MAchine Design and CAD Presentation. its topic is about Hydrodynamic Journal bearings, Heat Generated in a Journal Bearing
Design Procedure for Journal Bearing
And Examples
Q.1 A single plate clutch with both sides of the plate effective is required to transmit 25 kW at 1600 r.p.m. The outer diameter of the plate is limited to 300 mm and the intensity of pressure between the plates not to exceed 0.07N / m * m ^ 2 Assuming uniform wear and coefficient of friction 0.3, find the inner diameter of the plates and the axial force necessary to engage the clutch.
Q.2 A multiple disc clutch has radial width of the friction material as 1/5th of the maximum radius. The coefficient of friction is 0.25. Find the total number of discs required to transmit 60 kW at 3000 r.p.m. The maximum diameter of the clutch is 250 mm and the axial force is limited to 600 N. Also find the mean unit pressure on each contact surface.
Q.3 A cone clutch is to be designed to transmit 7.5 kW at 900 r.p.m. The cone has a face angle of 12°. The width of the face is half of the mean radius and the normal pressure between the contact faces is not to exceed 0.09 N/mm². Assuming uniform wear and the coefficient of friction between the contact faces as 0.2, find the main dimensions of the clutch and the axial force required to engage the clutch.
Q.4 A cone clutch is mounted on a shaft which transmits power at 225 r.p.m. The small diameter of the cone is 230 mm, the cone face is 50 mm and the cone face makes an angle of 15 deg with the horizontal. Determine the axial force necessary to engage the clutch to transmit 4.5 kW if the coefficient of friction of the contact surfaces is 0.25. What is the maximum pressure on the contact surfaces assuming uniform wear?
Q.5 A soft surface cone clutch transmits a torque of 200 N-m at 1250 r.p.m. The larger diameter of the clutch is 350 mm. The cone pitch angle is 7.5 deg and the face width is 65 mm. If the coefficient of friction is 0.2. find:
1. the axial force required to transmit the torque:
2. the axial force required to engage the clutch;
3. the average normal pressure on the contact surfaces when the maximum torque is being transmitted; and
4. the maximum normal pressure assuming uniform wear.
Q.6 A single block brake, as shown in Fig. 1. has the drum diameter 250 mm. The angle of contact is 90° and the coefficient of friction between the drum and the lining is 0.35. If the torque transmitted by the brake is 70 N-m, find the force P required to operate the brake. Q.7 The layout and dimensions of a double shoe brake is shown in Fig. 2. The diameter of the
brake drum is 300 mm and the contact angle for each shoe is 90°. If the coefficient of friction for the brake lining and the drum is 0.4, find the spring force necessary to transmit a torque of 30 N-m. Also determine the width of the brake shoes, if the bearing pressure on the lining material is not to exceed 0.28N / m * m ^ 2
This document discusses belt, rope, and chain drives used to transmit power between rotating shafts. It describes factors that affect the amount of power transmitted by belts, such as velocity, tension, and arc of contact. It also outlines conditions for proper belt use, types of belt drives based on power level, and sources of belt slippage. Additionally, it provides details on chain drives, including types of chains, construction, geometry considerations for sprockets and chain length, and recommended angle of contact.
Metal casting is a manufacturing process where liquid metal is poured into a mold and solidifies. Sand casting is a common type of metal casting that uses sand as the mold material. Key steps in sand casting include pattern making, molding, melting and pouring the metal, solidification, and cleaning. Sand provides advantages as a mold material such as low cost, high temperature stability, and permeability. Shell molding is an alternative casting method that uses a resin-bonded sand mixture to form the mold around a pattern.
This document discusses the design of shafts that can experience twisting moments, bending moments, or a combination of both. It provides equations to determine the diameter of shafts subjected to twisting moments only based on the torque and material shear stress. Similarly, it gives equations for sizing shafts experiencing bending moments only based on the bending moment and material bending stress. For shafts with combined loads, it describes two failure theories and the resulting equivalent moment equations that can be used for design.
1. The document discusses the constitution of alloys and phase diagrams. It describes different types of solid solutions like substitutional and interstitial solutions and classifies phase diagrams as unary, binary, and ternary.
2. The iron-iron carbide equilibrium diagram is examined in detail. It identifies the various phases involved like ferrite, austenite, and cementite. Critical temperatures like A1, A2, A3 are defined.
3. The microstructure and properties of steels and cast irons are determined by their position in the iron-carbon phase diagram and the phases present at room temperature. Hypoeutectoid steels contain ferrite and pearlite while hyp
This document provides an overview of casting processes and patterns used in manufacturing. It discusses various types of foundries based on production levels. Patterns are models used to form mold cavities and can be made from various materials like wood, metal, and plastic. Allowances must be provided in patterns to account for shrinkage, draft, machining needs, and potential distortions during solidification. Different types of patterns are used depending on the part geometry, including single-piece, split, gated, sweep, and skeleton patterns.
It is about introduction of gear train, its types and a little bit information about its types. After this PPT you'll get basic idea about Gear train and it's types.
Q.1 A single plate clutch with both sides of the plate effective is required to transmit 25 kW at 1600 r.p.m. The outer diameter of the plate is limited to 300 mm and the intensity of pressure between the plates not to exceed 0.07N / m * m ^ 2 Assuming uniform wear and coefficient of friction 0.3, find the inner diameter of the plates and the axial force necessary to engage the clutch.
Q.2 A multiple disc clutch has radial width of the friction material as 1/5th of the maximum radius. The coefficient of friction is 0.25. Find the total number of discs required to transmit 60 kW at 3000 r.p.m. The maximum diameter of the clutch is 250 mm and the axial force is limited to 600 N. Also find the mean unit pressure on each contact surface.
Q.3 A cone clutch is to be designed to transmit 7.5 kW at 900 r.p.m. The cone has a face angle of 12°. The width of the face is half of the mean radius and the normal pressure between the contact faces is not to exceed 0.09 N/mm². Assuming uniform wear and the coefficient of friction between the contact faces as 0.2, find the main dimensions of the clutch and the axial force required to engage the clutch.
Q.4 A cone clutch is mounted on a shaft which transmits power at 225 r.p.m. The small diameter of the cone is 230 mm, the cone face is 50 mm and the cone face makes an angle of 15 deg with the horizontal. Determine the axial force necessary to engage the clutch to transmit 4.5 kW if the coefficient of friction of the contact surfaces is 0.25. What is the maximum pressure on the contact surfaces assuming uniform wear?
Q.5 A soft surface cone clutch transmits a torque of 200 N-m at 1250 r.p.m. The larger diameter of the clutch is 350 mm. The cone pitch angle is 7.5 deg and the face width is 65 mm. If the coefficient of friction is 0.2. find:
1. the axial force required to transmit the torque:
2. the axial force required to engage the clutch;
3. the average normal pressure on the contact surfaces when the maximum torque is being transmitted; and
4. the maximum normal pressure assuming uniform wear.
Q.6 A single block brake, as shown in Fig. 1. has the drum diameter 250 mm. The angle of contact is 90° and the coefficient of friction between the drum and the lining is 0.35. If the torque transmitted by the brake is 70 N-m, find the force P required to operate the brake. Q.7 The layout and dimensions of a double shoe brake is shown in Fig. 2. The diameter of the
brake drum is 300 mm and the contact angle for each shoe is 90°. If the coefficient of friction for the brake lining and the drum is 0.4, find the spring force necessary to transmit a torque of 30 N-m. Also determine the width of the brake shoes, if the bearing pressure on the lining material is not to exceed 0.28N / m * m ^ 2
This document discusses belt, rope, and chain drives used to transmit power between rotating shafts. It describes factors that affect the amount of power transmitted by belts, such as velocity, tension, and arc of contact. It also outlines conditions for proper belt use, types of belt drives based on power level, and sources of belt slippage. Additionally, it provides details on chain drives, including types of chains, construction, geometry considerations for sprockets and chain length, and recommended angle of contact.
Metal casting is a manufacturing process where liquid metal is poured into a mold and solidifies. Sand casting is a common type of metal casting that uses sand as the mold material. Key steps in sand casting include pattern making, molding, melting and pouring the metal, solidification, and cleaning. Sand provides advantages as a mold material such as low cost, high temperature stability, and permeability. Shell molding is an alternative casting method that uses a resin-bonded sand mixture to form the mold around a pattern.
This document discusses the design of shafts that can experience twisting moments, bending moments, or a combination of both. It provides equations to determine the diameter of shafts subjected to twisting moments only based on the torque and material shear stress. Similarly, it gives equations for sizing shafts experiencing bending moments only based on the bending moment and material bending stress. For shafts with combined loads, it describes two failure theories and the resulting equivalent moment equations that can be used for design.
1. The document discusses the constitution of alloys and phase diagrams. It describes different types of solid solutions like substitutional and interstitial solutions and classifies phase diagrams as unary, binary, and ternary.
2. The iron-iron carbide equilibrium diagram is examined in detail. It identifies the various phases involved like ferrite, austenite, and cementite. Critical temperatures like A1, A2, A3 are defined.
3. The microstructure and properties of steels and cast irons are determined by their position in the iron-carbon phase diagram and the phases present at room temperature. Hypoeutectoid steels contain ferrite and pearlite while hyp
This document provides an overview of casting processes and patterns used in manufacturing. It discusses various types of foundries based on production levels. Patterns are models used to form mold cavities and can be made from various materials like wood, metal, and plastic. Allowances must be provided in patterns to account for shrinkage, draft, machining needs, and potential distortions during solidification. Different types of patterns are used depending on the part geometry, including single-piece, split, gated, sweep, and skeleton patterns.
It is about introduction of gear train, its types and a little bit information about its types. After this PPT you'll get basic idea about Gear train and it's types.
The document discusses design considerations for castings. It notes that casting involves pouring molten material into a mold to create complex shapes. Successful casting requires controlling variables like the material, casting method, cooling rate, and gases. The document outlines design considerations like designing parts for easy casting, selecting suitable materials and processes, locating parting lines and gates, and including features like sprues and risers. It also discusses designing parts to avoid defects from things like shrinkage, stress concentrations, and uneven cooling. The document concludes by mentioning some common casting defects and factors in the economics of casting like costs of molds, materials, and production rates.
This document discusses different types of phase diagrams that can be used to represent alloy systems. It describes four main types:
1) Complete solid solubility - The metals are soluble in both the liquid and solid states, forming a substitutional solid solution.
2) No solid solubility - The metals are soluble only in the liquid state and insoluble in the solid state, resulting in separate metal phases.
3) Partial solid solubility - The metals are soluble in the liquid state but only partially soluble in the solid state, allowing for intermediate phases.
4) Congruent melting - One phase changes isothermally into another phase without changing composition, represented as a vertical line on the phase diagram
Numerical methods for 2 d heat transferArun Sarasan
This document presents a numerical study comparing finite difference and finite volume methods for solving the heat transfer equation during solidification in a complex casting geometry. The study uses a multi-block grid with bilinear interpolation and generalized curvilinear coordinates. Results show good agreement between the two discretization methods, with a slight advantage for the finite volume method due to its use of more nodal information. The multi-block grid approach reduces computational time and allows complex geometries to be accurately modeled while overcoming issues at block interfaces.
This document provides information about lathe machines, including their construction, types, and specifications. It discusses the main components of lathes like the bed, headstock, tailstock, and carriage. It describes different types of lathes such as speed lathes, engine lathes, bench lathes, tool room lathes, capstan and turret lathes, and automatic lathes. It also covers topics like lathe operations, taper turning methods, thread cutting, and lathe attachments. Specification factors for lathes like height of centers, swing diameter, length between centers are defined.
Definition, Use, Types of beariings, Types of Journal bearing, Materials for journal bearing, Failures of journal bearing, Design terms for journal bearing, Types of roller contact bearing, applications of roller contact bearing, Designation of roller contact bearing, Design terms for roller contact bearing, comparison between journal and roller bearings, characteristics of bearings, selection procedure of bearings
Shell mold casting is a metal casting process that uses a resin-coated sand mixture to form a thin-walled mold shell around a metal pattern. The pattern is heated and pressed into the sand-resin mixture to form the shell, which is then cured in an oven. Two shell halves are joined to form the complete shell mold, into which molten metal is poured to create the casting. This allows for high-precision casting of small to medium parts like gear housings, cylinder heads, and connecting rods. The shell mold casting process provides advantages over sand casting like better surface finish and dimensional accuracy for the final casting.
The document discusses measurement and metrology of screw threads. It begins with definitions of screw thread terminology such as major diameter, minor diameter, pitch, angle, and forms of threads. It then describes methods for measuring the major diameter, minor diameter, effective diameter, and pitch of screw threads. The key measurement methods discussed are using micrometers, pitch gauges, and a tool maker's microscope. The goal is to understand principles and techniques for measuring characteristics of screw threads.
Heat can be transferred through conduction, convection, and radiation. Conduction involves the transfer of heat between objects in direct contact through collisions of atoms and molecules. It occurs at a rate directly proportional to the temperature gradient and the area, and inversely proportional to the material's thickness and thermal conductivity. Convection involves the transfer of heat by the circulation or movement of fluids such as gases and liquids, and can be natural or forced. Radiation is heat transfer between two bodies or a body and its environment without requiring physical contact. It occurs through electromagnetic waves.
Full mould casting is a casting process that uses an expanded polystyrene foam pattern surrounded by sand. Molten metal is poured directly into the mould, vaporizing the foam and allowing the metal to fill the entire mould cavity. This process is similar to lost wax casting but uses a thermally decomposable foam pattern instead of wax. The foam pattern can be designed using computer tools before the casting process. Some advantages are it is cheaper than investment casting, requires no drafts or risers, and has good dimensional accuracy and surface finish.
This document discusses optimization of cutting conditions for metal cutting operations. It introduces key factors like cutting speed, feed rate, and tool life that impact production time and cost. Equations are presented to calculate the optimum cutting speed and tool life that give minimum production cost and time. The relationships between these variables are illustrated with graphs. The document also provides examples of how to estimate costs for machine tools, operators, and tools to determine optimal cutting conditions for a given machining operation.
This document provides an overview of manufacturing processes and riser design concepts. It discusses solidification of castings, functions of risers, types of risers, and methods for riser design including the Chvorinov rule, modulus method, and NRL method. Examples are provided to demonstrate how to calculate riser dimensions using these methods based on properties of the casting such as volume, surface area, and solidification time.
Unit 4- balancing of rotating masses, Dynamics of machines of VTU Syllabus prepared by Hareesha N Gowda, Asst. Prof, Dayananda Sagar College of Engg, Blore. Please write to hareeshang@gmail.com for suggestions and criticisms.
Effectiveness for Counterflow heat exchangerElesh Koshti
1) The document discusses counter-flow heat exchangers and defines the logarithmic mean temperature difference (LMTD) for calculating heat transfer in counter-flow exchangers.
2) It then defines effectiveness as the ratio of actual heat transfer to maximum possible heat transfer and derives an equation for effectiveness in terms of the number of transfer units (NTU) and heat capacity ratio (R).
3) An example problem is then presented to calculate the mass flow rate of cooling water, effectiveness, and required heat exchange area for a given counter-flow exchanger problem.
This document discusses metallurgy and material science, specifically focusing on the iron-carbon phase diagram and the microstructures and transformations associated with steels. It describes the five individual phases in the Fe-C diagram, including ferrite, austenite, cementite, and liquid. It also discusses the three invariant reactions of peritectic, eutectic, and eutectoid. The document classifies different types of steels and cast irons based on their carbon content and describes the microstructures of hypoeutectoid, eutectoid, and hypereutectoid steels. It also discusses phase transformations in steels including pearlite, bainite, and martensite
The document provides information on different types of drilling machines. It discusses portable drilling machines, sensitive drilling machines, upright drilling machines, pillar drilling machines, radial drilling machines, and gang drilling machines. Upright drilling machines are larger and heavier than sensitive drilling machines and have power feed arrangements. Pillar drilling machines have a base, column, table, head, and spindle drive mechanism. Radial drilling machines can drill heavy workpieces in any position without needing to move them.
Patterns are models used to form cavities in molds for metal casting. There are different types of patterns based on their construction:
- Solid or one-piece patterns are made from a single piece for simple castings.
- Split patterns are made in two pieces for more complex shapes, with dowel pins to align the pieces.
- Loose-piece patterns have removable pieces to allow pattern withdrawal, connected by dowel pins.
- Match-plate patterns mount multiple split patterns on a plate, which is positioned between cope and drag molds.
Patterns are made larger than the intended casting to allow for material shrinkage and machining during production. Allowances are also made for draft,
This document provides an overview of the design of internal combustion (I.C.) engine components. It discusses the classification of I.C. engines as either diesel or petrol, two-stroke or four-stroke. Key engine components are described, including the cylinder, piston, connecting rod, crankshaft, and valve gear system. Design considerations and equations for determining dimensions of each component based on factors like material properties, engine size, speed, and operating pressures are presented. Guidelines are provided for thickness of walls, liners, heads, studs, rings, pins, and bearings.
Fabrication of metal matrix composites using stir casting methodAbhishekKumarSingh252
This document summarizes a project to fabricate metal-matrix composites using stir casting. The project aims to produce aluminum-silicon carbide (AlSiC) composites through stir casting to create strong, lightweight materials for use in industries like automotive and aerospace. Experiments are conducted by varying the composition of silicon carbide added to molten aluminum from 5-30% and stirring to ensure homogeneous mixing. The composites are then tested for properties like hardness and impact strength. The goal is to develop low-cost metal-matrix composite materials for industrial applications requiring high strength, stiffness, and other properties.
This presentation contains basic idea regarding spur gear and provides the best equations for designing of spur gear. One can Easily understand all the parameters required to design a Spur Gear
Here are the key steps to design a journal bearing from the given data:
1. Choose a length to diameter ratio (l/d) of 1.5 from the design handbook table.
2. Calculate the bearing pressure p = Load / (Length x Diameter). Check it is less than the maximum allowed.
3. Choose the lubricant SAE 10 and operating temperature of 55°C from the tables.
4. Calculate the bearing characteristic number K = (Viscosity x Speed) / Pressure. Check it exceeds the minimum value.
5. Choose a clearance ratio c/d from the table.
6. Calculate the coefficient of friction using the relation.
7.
lecture 4 (design procedure of journal bearing)ashish7185
This document provides information about the design procedure for sliding contact bearings. It defines key terms used in hydrodynamic journal bearings such as diametral clearance, radial clearance, eccentricity, minimum oil film thickness, and short/long bearings. It discusses bearing characteristic number and bearing modulus, and how they relate to the coefficient of friction. Equations are provided for critical pressure, heat generated in bearings, and heat dissipated by bearings. The design procedure involves selecting bearing dimensions, material properties, operating parameters, and verifying thermal equilibrium conditions.
The document discusses design considerations for castings. It notes that casting involves pouring molten material into a mold to create complex shapes. Successful casting requires controlling variables like the material, casting method, cooling rate, and gases. The document outlines design considerations like designing parts for easy casting, selecting suitable materials and processes, locating parting lines and gates, and including features like sprues and risers. It also discusses designing parts to avoid defects from things like shrinkage, stress concentrations, and uneven cooling. The document concludes by mentioning some common casting defects and factors in the economics of casting like costs of molds, materials, and production rates.
This document discusses different types of phase diagrams that can be used to represent alloy systems. It describes four main types:
1) Complete solid solubility - The metals are soluble in both the liquid and solid states, forming a substitutional solid solution.
2) No solid solubility - The metals are soluble only in the liquid state and insoluble in the solid state, resulting in separate metal phases.
3) Partial solid solubility - The metals are soluble in the liquid state but only partially soluble in the solid state, allowing for intermediate phases.
4) Congruent melting - One phase changes isothermally into another phase without changing composition, represented as a vertical line on the phase diagram
Numerical methods for 2 d heat transferArun Sarasan
This document presents a numerical study comparing finite difference and finite volume methods for solving the heat transfer equation during solidification in a complex casting geometry. The study uses a multi-block grid with bilinear interpolation and generalized curvilinear coordinates. Results show good agreement between the two discretization methods, with a slight advantage for the finite volume method due to its use of more nodal information. The multi-block grid approach reduces computational time and allows complex geometries to be accurately modeled while overcoming issues at block interfaces.
This document provides information about lathe machines, including their construction, types, and specifications. It discusses the main components of lathes like the bed, headstock, tailstock, and carriage. It describes different types of lathes such as speed lathes, engine lathes, bench lathes, tool room lathes, capstan and turret lathes, and automatic lathes. It also covers topics like lathe operations, taper turning methods, thread cutting, and lathe attachments. Specification factors for lathes like height of centers, swing diameter, length between centers are defined.
Definition, Use, Types of beariings, Types of Journal bearing, Materials for journal bearing, Failures of journal bearing, Design terms for journal bearing, Types of roller contact bearing, applications of roller contact bearing, Designation of roller contact bearing, Design terms for roller contact bearing, comparison between journal and roller bearings, characteristics of bearings, selection procedure of bearings
Shell mold casting is a metal casting process that uses a resin-coated sand mixture to form a thin-walled mold shell around a metal pattern. The pattern is heated and pressed into the sand-resin mixture to form the shell, which is then cured in an oven. Two shell halves are joined to form the complete shell mold, into which molten metal is poured to create the casting. This allows for high-precision casting of small to medium parts like gear housings, cylinder heads, and connecting rods. The shell mold casting process provides advantages over sand casting like better surface finish and dimensional accuracy for the final casting.
The document discusses measurement and metrology of screw threads. It begins with definitions of screw thread terminology such as major diameter, minor diameter, pitch, angle, and forms of threads. It then describes methods for measuring the major diameter, minor diameter, effective diameter, and pitch of screw threads. The key measurement methods discussed are using micrometers, pitch gauges, and a tool maker's microscope. The goal is to understand principles and techniques for measuring characteristics of screw threads.
Heat can be transferred through conduction, convection, and radiation. Conduction involves the transfer of heat between objects in direct contact through collisions of atoms and molecules. It occurs at a rate directly proportional to the temperature gradient and the area, and inversely proportional to the material's thickness and thermal conductivity. Convection involves the transfer of heat by the circulation or movement of fluids such as gases and liquids, and can be natural or forced. Radiation is heat transfer between two bodies or a body and its environment without requiring physical contact. It occurs through electromagnetic waves.
Full mould casting is a casting process that uses an expanded polystyrene foam pattern surrounded by sand. Molten metal is poured directly into the mould, vaporizing the foam and allowing the metal to fill the entire mould cavity. This process is similar to lost wax casting but uses a thermally decomposable foam pattern instead of wax. The foam pattern can be designed using computer tools before the casting process. Some advantages are it is cheaper than investment casting, requires no drafts or risers, and has good dimensional accuracy and surface finish.
This document discusses optimization of cutting conditions for metal cutting operations. It introduces key factors like cutting speed, feed rate, and tool life that impact production time and cost. Equations are presented to calculate the optimum cutting speed and tool life that give minimum production cost and time. The relationships between these variables are illustrated with graphs. The document also provides examples of how to estimate costs for machine tools, operators, and tools to determine optimal cutting conditions for a given machining operation.
This document provides an overview of manufacturing processes and riser design concepts. It discusses solidification of castings, functions of risers, types of risers, and methods for riser design including the Chvorinov rule, modulus method, and NRL method. Examples are provided to demonstrate how to calculate riser dimensions using these methods based on properties of the casting such as volume, surface area, and solidification time.
Unit 4- balancing of rotating masses, Dynamics of machines of VTU Syllabus prepared by Hareesha N Gowda, Asst. Prof, Dayananda Sagar College of Engg, Blore. Please write to hareeshang@gmail.com for suggestions and criticisms.
Effectiveness for Counterflow heat exchangerElesh Koshti
1) The document discusses counter-flow heat exchangers and defines the logarithmic mean temperature difference (LMTD) for calculating heat transfer in counter-flow exchangers.
2) It then defines effectiveness as the ratio of actual heat transfer to maximum possible heat transfer and derives an equation for effectiveness in terms of the number of transfer units (NTU) and heat capacity ratio (R).
3) An example problem is then presented to calculate the mass flow rate of cooling water, effectiveness, and required heat exchange area for a given counter-flow exchanger problem.
This document discusses metallurgy and material science, specifically focusing on the iron-carbon phase diagram and the microstructures and transformations associated with steels. It describes the five individual phases in the Fe-C diagram, including ferrite, austenite, cementite, and liquid. It also discusses the three invariant reactions of peritectic, eutectic, and eutectoid. The document classifies different types of steels and cast irons based on their carbon content and describes the microstructures of hypoeutectoid, eutectoid, and hypereutectoid steels. It also discusses phase transformations in steels including pearlite, bainite, and martensite
The document provides information on different types of drilling machines. It discusses portable drilling machines, sensitive drilling machines, upright drilling machines, pillar drilling machines, radial drilling machines, and gang drilling machines. Upright drilling machines are larger and heavier than sensitive drilling machines and have power feed arrangements. Pillar drilling machines have a base, column, table, head, and spindle drive mechanism. Radial drilling machines can drill heavy workpieces in any position without needing to move them.
Patterns are models used to form cavities in molds for metal casting. There are different types of patterns based on their construction:
- Solid or one-piece patterns are made from a single piece for simple castings.
- Split patterns are made in two pieces for more complex shapes, with dowel pins to align the pieces.
- Loose-piece patterns have removable pieces to allow pattern withdrawal, connected by dowel pins.
- Match-plate patterns mount multiple split patterns on a plate, which is positioned between cope and drag molds.
Patterns are made larger than the intended casting to allow for material shrinkage and machining during production. Allowances are also made for draft,
This document provides an overview of the design of internal combustion (I.C.) engine components. It discusses the classification of I.C. engines as either diesel or petrol, two-stroke or four-stroke. Key engine components are described, including the cylinder, piston, connecting rod, crankshaft, and valve gear system. Design considerations and equations for determining dimensions of each component based on factors like material properties, engine size, speed, and operating pressures are presented. Guidelines are provided for thickness of walls, liners, heads, studs, rings, pins, and bearings.
Fabrication of metal matrix composites using stir casting methodAbhishekKumarSingh252
This document summarizes a project to fabricate metal-matrix composites using stir casting. The project aims to produce aluminum-silicon carbide (AlSiC) composites through stir casting to create strong, lightweight materials for use in industries like automotive and aerospace. Experiments are conducted by varying the composition of silicon carbide added to molten aluminum from 5-30% and stirring to ensure homogeneous mixing. The composites are then tested for properties like hardness and impact strength. The goal is to develop low-cost metal-matrix composite materials for industrial applications requiring high strength, stiffness, and other properties.
This presentation contains basic idea regarding spur gear and provides the best equations for designing of spur gear. One can Easily understand all the parameters required to design a Spur Gear
Here are the key steps to design a journal bearing from the given data:
1. Choose a length to diameter ratio (l/d) of 1.5 from the design handbook table.
2. Calculate the bearing pressure p = Load / (Length x Diameter). Check it is less than the maximum allowed.
3. Choose the lubricant SAE 10 and operating temperature of 55°C from the tables.
4. Calculate the bearing characteristic number K = (Viscosity x Speed) / Pressure. Check it exceeds the minimum value.
5. Choose a clearance ratio c/d from the table.
6. Calculate the coefficient of friction using the relation.
7.
lecture 4 (design procedure of journal bearing)ashish7185
This document provides information about the design procedure for sliding contact bearings. It defines key terms used in hydrodynamic journal bearings such as diametral clearance, radial clearance, eccentricity, minimum oil film thickness, and short/long bearings. It discusses bearing characteristic number and bearing modulus, and how they relate to the coefficient of friction. Equations are provided for critical pressure, heat generated in bearings, and heat dissipated by bearings. The design procedure involves selecting bearing dimensions, material properties, operating parameters, and verifying thermal equilibrium conditions.
Design of Machine Elements - Unit 5 Procedures Kumaravel
This document discusses terms used in hydrodynamic journal bearings such as diameter clearance, radial clearance, diameteral clearance ratio, and minimum oil film thickness. It also discusses methods for determining the coefficient of friction, critical pressure, and Sommerfeld number for journal bearings. The document outlines a 10 step design procedure for selecting journal bearings including calculating bearing size, pressure, clearance, characteristics number, heat generation, and material selection. It also discusses components, types, and selection procedures for rolling element bearings.
The document discusses sliding contact bearings and hydrodynamic journal bearings. It provides classifications of bearings based on the nature of contact, advantages and disadvantages of sliding contact bearings over rolling contact bearings. It describes hydrodynamic and hydrostatic bearings. The document also includes examples of design calculations for hydrodynamic journal bearings, including determining minimum oil film thickness, coefficient of friction, power loss, oil flow rate, side leakage, and oil temperature selection.
1) The document provides two examples of designing journal bearings for centrifugal pumps. The first example calculates the dimensions, operating characteristics, and heat generation of a journal bearing. It determines artificial cooling is required.
2) The second example calculates the artificial cooling required and mass of lubricating oil needed to limit temperature rise to 10°C for a journal bearing operating at 1.4 N/mm^2 pressure and 900 rpm. It determines values for heat generation, dissipation, and lubricating oil mass.
3) Throughout, the document refers to design data and equations from the referenced machine design textbook to analyze and size the journal bearings.
Plain bearings are components used between machine parts that have relative motion to reduce friction and wear. There are two main types: plain/bush/sleeve bearings and anti-friction/ball/roller bearings. Plain bearings support rotary motion like in shafts and wheels or linear motion like in pistons. They are commonly made of materials like cast iron, brass, bronze, and polymers. The design of boundary lubricated plain bearings involves selecting materials based on properties like strength, ductility, and corrosion resistance. Dimensions are found using parameters like bearing pressure, velocity, and their product, ensuring they are below maximum allowable limits in design tables.
Design of sliding_contact_wearing_unitiiibalram yadav
A bearing is a machine element which support another moving machine element (known as journal). It permits a relative motion between the contact surfaces of the members, while carrying the load.
Effect of Bearing Design Parameters on the Minimum Oil Film Thickness of Hydr...IRJET Journal
This document discusses the effect of bearing design parameters on the minimum oil film thickness of hydrodynamic journal bearings. It presents a bearing design procedure that involves iteratively calculating heat generation and dissipation until they are equal, indicating stable operating temperature. Parameters like lubricant grade, geometry ratios (L/D and R/C), and lubrication system affect the minimum film thickness. The procedure determines operating temperature, viscosity, pressure, friction, and minimum film thickness for given load and speed conditions. Computer-aided design allows efficiently varying parameters to compare their influence on minimum film thickness.
This document provides an introduction to sliding contact bearings. It discusses the basic functions and applications of bearings, and classifications of bearings based on load direction and contact type. Specifically, it covers radial and thrust bearings, and sliding and rolling contact bearings. It describes the components, operation, and types of sliding contact or plain bearings, including journal, slipper, and thrust bearings. Key terms related to hydrodynamic journal bearings like diametral clearance are also defined.
Design Optimization and Analysis of a Steam Turbine Rotor GroovesIOSR Journals
1. The document describes a finite element analysis performed to optimize the design of steam turbine rotor grooves.
2. The analysis evaluated different fillet radii ranging from 13 to 50 mm to determine the maximum principal stress and stress concentration factor.
3. The optimal design was found to have a fillet radius of 40 mm, which reduced the stress concentration factor to 1.152 and deformation to 0.066121 mm.
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3. List of topics
Terms used in Hydrodynamic Journal Bearing
Bearing Characteristic Number and Bearing Modulus for Journal
Bearings
Coefficient of Friction for Journal Bearings
Critical Pressure of the Journal Bearing
Sommerfeld Number
Heat Generated in a Journal Bearing
Design Procedure for Journal Bearing
And Examples from 26.1 to 26.5
4. 1) Terms used in Hydrodynamic Journal Bearing
In Figure O is the Centre of the journal and O′ is the center of the
bearing.
Let D = Diameter of the bearing,
d = Diameter of the journal,
And l = Length of the bearing.
5. Terms used in Hydrodynamic Journal Bearing
Diametral Clearance
It the difference between the diameters of the bearing and the
journal.
c = D – d
Where,
c is the diametral clearance
D is the diameter of the bearing
And, d is the diameter of the journal
6. Terms used in Hydrodynamic Journal Bearing
Radial clearance
It is the difference between the radii of the bearing and the journal.
Diametral clearance ratio
It is the ratio of the diametral clearance to the diameter of the journal.
Diametral clearance ratio
7. Terms used in Hydrodynamic Journal Bearing
Eccentricity
It is the radial distance between the center (O) of the bearing and the displaced center
(O′) of the bearing under load. It is denoted by “e”.
e = c1 –h0
Minimum oil film thickness
It is the minimum distance between the bearing
and the journal, under complete lubrication
condition.
It is denoted by h0
and it occurs at the line of centers
8. Terms used in Hydrodynamic Journal Bearing
Attitude or eccentricity ratio
It is the ratio of the eccentricity to the radial clearance.
It is denoted by “ε”
9. Terms used in Hydrodynamic Journal Bearing
Short and long bearing
If the ratio of the length to the diameter of the journal (i.e. l / d) is
less than 1, then the bearing is said to be short bearing.
If the ratio of the length to the diameter of the journal (i.e. l / d) is
greater than 1, then the bearing is said to be long bearing.
10. 2) Bearing Characteristic Number and Bearing
Modulus for Journal Bearings
The coefficient of friction in design of bearings is of great importance,
because it affords a means for determining the loss of power due to
bearing friction.
It has been shown by experiments that the coefficient of friction for a
full lubricated journal bearing is a function of three variables, i.e.
1) ZN/ p 2) d /c 3) l /d
coefficient of friction expressed as
11. Bearing Characteristic Number and Bearing Modulus for
Journal Bearings
Where,
μ = Coefficient of friction,
φ = A functional relationship,
Z = Absolute viscosity of the lubricant, in kg / m-s,
N = Speed of the journal in r.p.m ,
p = Bearing pressure on the projected bearing area in N/mm2, = Load
on the journal ÷ l × d,
d = Diameter of the journal,
l = Length of the bearing, and
c = Diametral clearance.
The factor ZN / p is termed as bearing characteristic number and is a
dimensionless number.
The factor ZN/p helps to predict the performance of a bearing.
12. Bearing Characteristic Number and Bearing Modulus for Journal
Bearings
The curve PQ represents the thick film lubrication.
The curve Q and R, between this the
Viscosity or the speed (N) are so low, or the
Pressure P is also great that their
Combination ZN/P will reduce the film
Thickness so that partial metal to metal
Contact will occurs.
The curve △R represents the thin film
Or boundary lubrication or impact lubricant
Exist.
we see that the minimum amount of
Friction occurs at A, and at this point the
Value of ZN/P is known as bearing modulus.
Which is denoted by K.
13. Continue……
To prevent this condition the bearing should be designed for a value of ZN/P at
least3 times the minimum value of bearing modulus K.
If the bearing is subjected large fluctuation of load and heavy impact, the value
ZN/P=15K is used.
14. 3) Coefficient of Friction for Journal Bearings
In order to determine the coefficient of friction for well lubricated full journal
bearings, the following empirical relation established by McKee based on the
experimental data
Coefficient of friction
Where, Z is absolute viscosity of Lubricant in Kg/m-s
P is Bearing pressure on projected in N/mm2
N is the speed of journal in r.p.m.
d is the diameter of journal.
c is the diametral clearance
K is the factor to correct for end leakage.it depend upon the l/d
of the bearing.
15. 4) Critical Pressure of the Journal Bearing
The pressure at which the oil film breaks down so that metal to metal contact begins,
is known as critical pressure or the minimum operating pressure of the bearing.
It may be obtained by the following empirical relation, i.e.
Critical pressure or minimum operating pressure
Where , Z is in kg / m-s
16. 5) Sommerfeld Number
It is a dimensionless parameter used extensively in the design of
journal bearings.
Sommerfeld Number
17. 6) Heat Generated in a Journal Bearing
The heat generated in a bearing is due to the fluid friction of the part having
relative motion .
Heat generated in bearing;
Qg = μ.W.V N-m/s or J/s or watts
where
μ = Coefficient of friction,
W = Load on the bearing in N,
= Pressure on the bearing in N/mm2 × Projected area of the bearing in mm2
= p (l × d)
V = Rubbing velocity in m/s = πd N/60 ,d is in meters
N = Speed of the journal in r.p.m
18. Continue…
After the thermal equilibrium has been reached,
Heat will be dissipated at the outer surface of the bearing at the
same rate at which it is generated in the oil film.
Heat dissipated by the bearing(Qd);
Qd= C.A (t b – t a) J/s Or W i.e. (j/s=W)
Where,
C = Heat dissipation coefficient in W/m2/°C,
A = Projected area of the bearing in m2 = l × d,
tb= Temperature of the bearing surface in °C, and
ta = Temperature of the surrounding air in °C.
19. Continue…
It has been shown by experiments that the temperature of the bearing (tb) is
approximately mid-way between the temperature of the oil film (t0 ) and the
temperature of the outside air (ta).
20. 7) Design procedure for journal bearing
We know that when journal rotates in a bearing then large amount of heat gets
generated in a bearing due to fraction.
For the safe design of the journal bearing the dimension, speed of etc.
Dimension of journal and the type of
lubricant all should be selected in such a way
That the heat dissipation is maximum
Step for design of journal bearing
To determine the bearing length by choosing a ratio
Of l/d from table (26.3) for the desired application.
Check the bearing pressure with the corresponding (Pmaxi)value from table (26.3)
P=W/l.d <Pmaxi
According to the application the type and lubricant and its operating temp. (t0)
Can be selected from the table..,
For safe operation of journal bearing , the temperature should b/w 26.5°C ≤ to
≤60°C , with maximum temperature (t0) 82°C.
21. Continue …
Condition of lubricant will be determine from the bearing characteristic number ;
ZN/P compare this value with the minimum value of bearing Modulus(K) at minimum
point of friction
K= 1/3(ZN/P)
The value of ZN/P should be taken from the table (26.3)
a) if ZN/P <K , this for thin film or hydrostatic lubrication
b) if ZN/P > K ,this For Thick film or Hydrodynamic lubrication.
Determine coefficient of friction is given by;
µ=33/108 (ZN/P)(c/d)+K
The value of the c/d should be taken from the the table (26.3) .
Determine the heat generated in the bearing is given by
Qg = µ.V.W
where, V= velocity of rubbing ,
V= πdN/60, m/s
22. Continue….
Determine the heat dissipated from the bearing is given by;
Qd =C.A (t0 - ta )
Qd =C.l.d [1/2(t0 - ta )]
Determine the thermal equilibrium to see that the heat dissipate becomes at least
equal to the heat generated . In case of the heat generated is more then the heat
dissipated then either the bearing is redesigned or it is artificially cooled by water.
Artificial cooling (Qg > Qd ) is given by
Qt= m.s.t (mass. Specific .Temperature )
23. Given; W = 20 000 N ; N = 900 r.p.m, t0 = 55°C ; Z = 0.017 kg/m-s ; ta = 15.5°C ; p = 1.5 N/mm2 ; t
= 10°C ; C = 1232 W/m2/°C.
Solution :1) let us find the length of the journal ( l ), Assume the d of the journal ( d ) as 100 mm
l = 1.6 d = 1.6 × 100 = 160 mm …………Ans.
2) Bearing Pressure
p= 20 000 /160* 150=1.25
Z.N /p= 0.017 *900/ 1.25 =12.24
3)
From Table 26.3, we find that the operating value of
ZN/p=28
The minimum value of the bearing modulus at which the oil film will break is given by
3K=ZN/p
k = 1/3*(28)=9.33
Since the calculated value of bearing characteristic number 12.24 is more then 9.33
So, the bearing will operate under hydrodynamic conditions.
24. 4)
From Table 26.3, the clearance ratio (c/d) = 0.0013
5) coefficient of friction,
= 0.0031 + 0.002 = 0.0051 …… . [From Art. 26.13, k = 0.002]
6) Heat generated,
7) . Heat dissipated
… ( d” taken in meters)
25. We see that the heat generated is greater than the heat dissipated which
indicates that the bearing is warming up.
Therefore, either the bearing should be redesigned by taking t 0 = 63°C or the
bearing should be cooled artificially. We know that the amount of artificial
cooling required
= Heat generated – Heat dissipated
= Qg – Qd
= 480.7 – 389.3
= 91.4 W
>Mass of lubricating oil required for artificial cooling
Let m = Mass of the lubricating oil required for artificial cooling in kg / s.
We know that the heat taken away by the oil,
Qt = m.S.t = m × 1900 × 10= 19 000 m W
Equating this to the amount of artificial cooling required,
we have 19 000 m = 91.4
∴ m = 91.4 / 19 000 = 0.0048 kg / s = 0.288 kg / min Ans
26. Example 26.2. The load on the journal bearing is 150 kN due to turbine shaft of 300
mm diameter running at 1800 r.p.m. Determine the following 1. Length of the
bearing if the allowable bearing pressure is 1.6 N/mm2, and 2. Amount of heat to
be removed by the lubricant per minute if the bearing temperature is 60°C and
viscosity of the oil at 60°C is 0.02 kg/m-s and the bearing clearance is 0.25 mm.
Solution. Given : W = 150 kN = 150 × 103 N; d = 300 mm = 0.3 m ; N = 1800
r.p.m. ; p = 1.6 N/mm2 ; Z = 0.02 kg / m-s ; c = 0.25 mm
Length of the bearing
Let l = Length of the bearing in mm.
We know that projected bearing area,
A = l × d = l × 300 = 300 l mm2
and allowable bearing pressure ( p)
27. 2) Amount of heat to be removed by the lubricant