Antique Marine Steam Engine Solidoworks Project

1

Final Project: Antique Marine Steam Engine
Amy Gilliam
Michael Lagalle
Donovan Naghitorabi
Adrian Neyra
EML4024C
Monday 8:30am-11:20am
5/4/2015

2

Table of Contents
I. Introduction 3
II. Mechanical Design: Parts 4
1. Case Sub-Assembly Parts 4
2. Powertrain Sub-Assembly Parts 6
3. Cylinder Sub-Assembly Parts 12
4. Valve Sub-Assembly Parts 19
5. Piston Sub-Assembly Parts 22
6. Link Sub-Assembly Parts 24
7. Handle Sub-Assembly Parts 27
III. Mechanical Design: Assembly 29
1. Case Sub-Assembly 29
2. Powertrain Sub-Assembly 33
3. Cylinder Sub-Assembly 36
4. Valve Sub-Assembly 39
5. Piston Sub-Assembly 43
6. Link Sub-Assembly 44
7. Handle Sub-Assembly 49
8. Final Assembly 53
IV. Mechanism Model Mechanics 57
V. Mechanism Kinematics 57
VI. Structural Analysis 58
VII. Conclusion 60
VIII. References 60

3

I. Introduction
Steam engines are designed to perform mechanical work by utilizing the heat energy of
compressed steam. Originally invented by James Watt, for whom the corresponding unit of
power is named, the steam engine's advent was a critical development of the Industrial
Revolution, paving the way for many other inventions, such as the steamboat, steam trains, and
mills [1]. Steam engines function by using the pressure of compressed steam to apply force to a
piston or pistons, causing movement. For the purposes of this project, a steam engine was
modeled that utilizes eccentric components to account for the motion of a single piston. The
piston is linked to a powertrain assembly, which is housed within a case. The case is topped by a
cylinder which includes a ratchet-like piece that indicates the speed, to which the spring-loaded
handle is separately joined for control of the engine. The full assembly consists of seven sub-
assemblies and 52 individual components, not counting standard fasteners. For the sake of
modeling accuracy and time, standard fasteners were utilized from the McMaster-Carr website,
which are available for public use for this purpose [2]. The steam engine selected for this project
was designed to be utilized in marine applications and resembles one that might have been used
in the early 1900s. [3] This project was created using SolidWorks 2014. An image of the final
product is shown in Figure 1. This report will include descriptions of each of the parts and
instructions on how the sub-assemblies were created. It will also include analysis regarding the
mechanical properties of the assembly and its kinematics, as well as structural analysis and a
concluding statement.
Figure 1. Marine Steam Engine, full assembly

4

II. Mechanical Design: Parts
1. Case Sub-Assembly Parts
1.1 Case
The case is designed to house the main components of the steam engine, designed to
protect both the components inside the engine and to protect the operators from potential moving
object hazards. Because it is designed to house many components with little room for error, it is
a very complex piece, created from a large number of features, including boss extrusions,
revolved extrusions, extruded cuts, shells, sweeps, circular patterns, and mirrored features,
providing an opportunity to explore nearly every technique learned during this course. The case
is composed of cast alloy steel and is shown in Figure 2.
Figure 2. Case
1.2 Throttle Support
The throttle support is connected to the handle sub-assembly in the full assembly and
rests on the side of the case in the sub-assembly. The throttle support began as a boss extrusion
with cuts made to create the edges and to create the holes for fasteners. A revolved feature
created the shaft, and additional extruded cuts created the threads along the shaft and the nested
parts for where the fasteners will rest. The throttle support is composed of cast alloy steel. It is
shown in Figure 3.

5

Figure 3. Throttle support
1.3 Bushing
The bushing rests between the case and the main bearing cap in the assembly. It is a
simple piece, created from a single linear boss extrusion. The bushing is composed of brass. It is
shown in Figure 4.
Figure 4. Bushing
1.4 Main Bearing Cap
The main bearing cap is connected to the case around the bushing in the sub-assembly. It
is created with a pair of boss extrusions to create the main surfaces, with cut extrusions to create
the holes for the bushing and fasteners. A revolved extrusion and cut revolve are used to create
the hole in the center. The main bearing cap is composed of gray cast iron and is shown in Figure
5.

6

Figure 5. Main bearing cap
2. Powertrain Sub-Assembly Parts
2.1 Crankshaft
The crankshaft is what transmits the torque to the flywheel in the assembly. It also
connects to the link and is forced to rotate by the piston’s movement. The crankshaft was created
using boss- and cut-extrusions. Due to the nature of the disks attached to it, the crankshaft could
not be completed using a single revolve feature, and design intent could be better achieved by
using extrusions. However, the cuts along the disc features were created by cut-revolving a
triangle 360 degrees along their center lines. The part is composed of cast alloy steel. The
completed part is displayed in Figure 6.
Figure 6. Crankshaft
2.2 Flywheel
The flywheel is the last driven part in the assembly. One could connect a belt to the
flywheel to drive another part. The flywheel was created using a series of extrusions and cuts,

7

and most notably, three circular patterns were used for the cuts and small arc features. The
flywheel is composed of cast iron. The completed part is displayed in Figure 7.
Figure 7. Flywheel
2.3 Crank Pin
The crank pin connects the two halves of the crankshaft together. The crank pin was
created using a single extruded boss. The crank pin is composed of aluminum bronze. The
completed part is displayed in Figure 8.
Figure 8. Crank pin
2.4 Connecting Rod End Cap
The connecting rod end cap surrounds one half of the crank pin as part of the connection
to the piston. It is designed to rotate around the crank pin. This part was designed in one half,
which was then mirrored along the center plane. This was done due to the symmetry of the part
and saved time. The connecting rod end cap is composed of cast alloy steel. The completed part
is displayed in Figure 9.

8

Figure 9. Connecting rod end cap
2.5 Connecting Rod Center Block
The connecting rod center block sits on top of the connecting rod end cap, with the cap’s
pins sliding into its holes. It surrounds the other half of the crank pin as well. The connecting rod
center block is composed of cast alloy steel. The completed part is displayed in Figure 10.
Figure 10. Connecting rod center block
2.6 Connecting Rod
The connecting rod connects the crank shaft to the piston assembly. It sits on top of the
connecting rod center block and is secured with hex bolts. One significant feature in this part is
the one degree draft angle applied to the rod, increasing the diameter to its maximum at its

9

middle. The connecting rod is composed of cast alloy steel. The completed part is displayed in
Figure 11.
Figure 11. Connecting rod
2.7 Connecting Rod Insert
The connecting rod insert fits inside the top of the connecting rod. It was created with a
single boss extrude. The connecting rod insert is composed of aluminum bronze. The completed
part is displayed in Figure 12.
Figure 12. Connecting rod insert
2.8 Slipper
The slipper serves a very important purpose. It surrounds the connecting rod insert such
that the two parts’ circular cuts are concentric. The piston slides into the top hole of the slipper
and a pin runs through it, connecting it to the connecting rod insert. This allows the slipper to
rotate about the connecting rod insert, so that its top face can remain parallel to the floor, thereby

10

letting the piston move vertically. The slipper is composed of cast alloy steel. The completed part
Figure 13. Slipper
2.9 Connecting Rod Pin
The connecting rod pin slides into the slipper and serves to allow it to rotate, letting the
piston move vertically. It was created with a single revolved extrusion. The connecting rod pin is
composed of cast alloy steel. The completed part is displayed in Figure 14.
Figure 14. Connecting rod pin
2.10 Slipper Guide
The slipper guides connect to the slipper and slide along the interior of the case. Due to
their dynamic cross-sections, lofts were used in their design. The completed part is shown in
Figure 15.

11

Figure 15. Slipper guide
2.11 Collar half
The collar half is a simple, two-feature part whose purpose is to hug the exterior of the
case and help keep it in place. It was created with a boss extrusion to create the main structure
and an extruded cut to create the holes for fastener attachment to the assembly. It is composed of
cast alloy steel. The completed part is displayed in Figure 16.
Figure 16. Collar half

12

3. Cylinder Sub-Assembly Parts
3.1 Cylinder
The cylinder is the main hub of this sub assembly, and was the most complicated part of
this sub-assembly. All of the other sub-assemblies are connected to the Cylinder Sub-Assembly
in some form. This means that the connection slots must be exact, so as to not cause conflict with
any of the other sub-assemblies. The part is composed of cast iron. The part was made with
extrudes to get the two intersecting cylinders. The part was then cut away and shaped into the
cylinder shown in Figure 17.
Figure 17. Cylinder
3.2 Valve Cover
The valve cover is a very simple part that is designed to close the side of the cylinder. It
is also where the speed indicator will be attached. It was designed with a simple extruded boss of
a circle, and then the bolt holes were cut into it so that that they would line up perfectly with the
cylinders bolt holes. The extrude cut in the middle is for aesthetic reasons as well as eliminated
unneeded material. The valve cover is also composed of cast iron and is displayed in Figure 18.
Figure 18. Valve cover
3.3 Cylinder Cap
The cylinder cap is another simple part. This part is designed to close the top of the
cylinder. However, unlike the valve, the cylinder cap is designed to slide right on top of the
cylinder. It is designed with a sketch of a section view, which was then revolved around 360

13

degrees. This was to ensure that the that cap maintained the proper edge spacing between the
cylinder and itself. The cylinder cap is also composed of cast iron. The completed part can be
seen in Figures 19 and 20.
Figure 19. Cylinder cap, top view
Figure 20. Cylinder cap, bottom view
3.4 Cylinder Exhaust Valve
The Exhaust valve is designed to fit right into the top hole of the cylinder. This part is to
allow the exhaust of the engine to be vented out, as it sits on the chamber where the piston is
housed. It is designed with simple extrudes bosses and cuts, and then filleted to be aesthetically
pleasing. The hexagonal shape was created using the insert polygon sketch command and then
extruded up. The part is composed of brass and can be seen in Figure 21.

14

Figure 21. Cylinder exhaust valve
3.5 Bottom of Cylinder Packing Gland
The bottom of the packing gland is a simple part composed of cast alloy steel. It is
designed to close the gland and seal the cylinder holding a smaller rubber cylinder that serves as
a seal. It was designed with two simple extruded bosses, and then three holes extrude cut down
into the part. The beveling on the top face was done with a simple sketch that was revolved
around the central axis. The completed part is displayed in Figure 22.
Figure 22. Bottom of cylinder packing gland
3.6 Top of Cylinder Packing Gland
The top of the packing gland is also combined of cast alloy steel. It is designed to fit right
into the bottom of the main cylinder. It has a hollowed center, where the cylindrical packaging
will slide right into. It has two bolt holes that will align with bottom bolt holes of the cylinder as
well as the bolt holes on the bottom of the packing gland. The holes were created using extruded
cuts, and the detailed beveled work was done with revolved cuts. The final part can be seen in
Figure 23.

15

Figure 23. Top of packing gland
3.7 Packing for Cylinder
The packing for the cylinder is the packing that will go between the top and bottom
glands. It is a simple cylinder with beveled edges and a hole cut straight down the center. The
part is composed of a BUTYL rubber and is shown in Figure 24.
Figure 24. Packing for cylinder
3.8 Top of Valve Packing Gland
The valve packing gland has a similar intent as the cylinder packing gland. The top will
be inserted into the bottom of the horizontal cylinder. The part is composed of the same cast
alloy steel as the other packing system. This part was created in a very similar manner as the
exhaust valve. The complete part can be seen in Figure 25.
Figure 25. Top of valve packing gland

16

3.9 Bottom of Valve Packing Gland
The bottom of this packing gland is designed to screw right into the top connection of the
gland. The two parts are to house a packaging part which will serve as a seal. This bottom half
was designed with a rough sketch that was revolved, and then cut into shape. The final part can
be seen in Figure 26.
Figure 26. Bottom of valve packing gland
3.10 Valve Packing
The packing for the valve will go between the top and bottom glands. It is a simple
cylinder a rounded top and a hole cut straight down the center. The part is composed of a
BUTYL rubber and is shown in Figure 27.
Figure 27. Top of valve packing gland
3.11 Speed Indicator
The speed indicator controls the range of the piston firing. This in turn controls the speed
obtainable of the engine. The speed indicator was a complex part in terms of arriving at the
curve, that allowed for the proper speed setting placements. The part was made with simple
extrudes using the mid plane, after the sketch was completed. Then text was added onto the
handle at its corresponding notches. The part is composed of cast alloy steel. The finished part is
shown in Figure 28.

17

Figure 28. Speed indicator
3.12 Drain Cock
The drain cock is part of a ball valve that is attached to the bottom of the main cylinder. It
is a relatively simple part to design, with the use of revolves, mirrors, and the shell command.
There is an implied threading where the valve is connected to the cylinder. The drain cock is
composed of brass. The final part is shown in Figure 29.
Figure 29. Drain cock
3.12 Drain Cock Handle
The drain cock handle is the piece of the drain that rotates inside the drain cock. This
piece allows for drainage. It is designed to be like a ball valve, so it would be inserted into the
drain cock and rotate to open and close the path. This piece is also composed of brass. The part
was designed with revolved sketch of the grip, followed by a loft connecting the ball to the grip.
The drain cock handle can seen in Figure 30.

18

Figure 30. Drain Cock Handle
3.13 Pressure Valve Pipe
The pressure valve pipe is screwed into the side of the main cylinder. The pipe allows the
pressure valve to be screwed in. It was created with simple extrusions of circles and polygons,
then one cut down the center. The part is composed of brass. The final part is shown in Figure
31.
Figure 31. Pressure valve pipe
3.14 Pressure Valve
The pressure valve is the valve that adjusts the pressure level in the cylinder. It is a
simple round valve that has been shelled and beveled. It screws into the pressure valve pipe and
has slot where a acorn nut can sit and tighten the hold on the valve. The valve itself is made of
cast alloy steel. The finished part is show in Figure 32.

19

Figure 32. Pressure valve
3.15 Cylinder Packing Studs
The studs are used to lock the top of the cylinder packaging into the bottom of the main
cylinder. The bottom of the packaging is then bolted on to them using nuts, enclosing the
cylindrical package. The part was made with two simple extrudes from mid-plane. The studs are
composed of cast alloy steel. The finished part can be seen in Figure 33.
Figure 33. Cylinder Packing Studs
4. Valve Sub-Assembly Parts
4.1 Valve Rod Actuator
The valve rod actuator slides along the valve rod within the valve sub-assembly. It was
created with a revolved extrusion for the main shaft, with a series of boss extrusions to create the
shaft protruding from the side. A cut extrusion created the hole down the center. The part is
composed of aluminum bronze and is shown in Figure 34.

20

Figure 34. Valve rod actuator
4.2 Valve Rod
The valve rod is composed of a single circular extrusion, and in the sub-assembly it is
nested inside of the valve rod actuator, which moves along the valve rod. The part is composed
of alloy steel and is shown in Figure 35.
Figure 35. Valve rod
4.3 Slide Valve
The slide valve is the top piece of the valve sub-assembly. It was created with a boss
extrusion to create the main shape, with two blind cut extrudes to create the indentations in the
top and side. The slide valve is composed of aluminum bronze and is shown in Figure 36.

21

Figure 36. Slide valve
4.4 Sliding Block Front Piece
The sliding block front piece fits over the protruding rod of the valve rod actuator and lies
flush against the sliding block rear piece, creating a case to limit the motion of the actuating rod.
The part is created with a series of extrusions and cuts to create the details, including holes for
fastener attachments. There is also a fillet added to the inside edges of the slot. The sliding block
front piece is composed of cast alloy steel and is shown in Figure 37.
Figure 37. Sliding block front piece
4.5 Sliding Block Rear Piece
Some portions of this part were copied from the sliding block front piece to ensure a
proper fit. The sliding block rear piece also includes a base portion that allows the component to
be bolted to the full assembly, but lacks the slot in the front where the actuator's rod lives,
instead having a smooth base for the actuating rod to slide along. The sliding block rear piece is
composed of cast alloy steel and is shown in Figure 38.

22

Figure 38. Sliding block rear piece
4.6 Stephenson Valve Fastener
The Stephenson valve fastener is attached to the bottom of the valve rod actuator in the
valve sub assembly. It was created with a boss extrusion to create the hex nut-like portion at the
bottom, with a revolved extrusion to create the tapered cone and a revolved cut to create the
softened edges at the top of the hex nut. An extruded cut creates the hole in the center. The
Stephenson valve fastener is composed of aluminum and is shown in Figure 39.
Figure 39. Stephenson valve fastener
5. Piston Sub-Assembly Parts
5.1 Piston
The piston is what incoming steam interacts with inside the cylinder sub-assembly. The
piston was created using one extruded boss and two revolved cuts, and it is made out of cast
alloy steel. The completed part is shown in Figure 40.

23

Figure 40. Piston
5.2 Piston Rod
The piston rod is what was mated into the hinge body of the powertrain sub-assembly to
drive it. It is made of cast alloy steel and consists of a single revolved boss feature. The
completed part is shown in Figure 41.
Figure 41. Piston rod
5.3 Piston Ring
The piston ring fits into the revolved cuts on the piston. Unlike the piston and piston rod,
the piston rings are made out of cast iron. The completed part is shown in Figure 42.
Figure 42. Piston ring

24

6. Link Sub-Assembly Parts
6.1 Link
The link is a simply constructed piece, made with a single boss extrusion. It includes
three small holes at the bottom that are designed for bolts, where the eccentric rods will later be
attached and where the assembly will attach to the larger full assembly, and a larger slot where
the link screw bearing will fit. It is composed of cast alloy steel. The completed part is displayed
in Figure 43.
Figure 43. Link
6.2 Outer eccentric rod
The outer eccentric rod was one of the more complex parts in the design and required
numerous steps for its creation. The top section, where the piece will join with the link piece in
6.1, was created by using a boss extrude of the basic shape, with a hole cut out for the bolt to join
it with the link. Two separate lofts were used to create the middle segments of design, which
includes a slanted piece to allow it to easily pass over the inner eccentric rod. A combination of
boss extrusions, rotated cuts, and rotated extrusions was used to create the bottom part and the
handle on the side. The bottom is designed to be bolted to one of the eccentric rod caps, and the
fillets and protrusions are designed to match. It is composed of cast alloy steel. The completed
part is displayed in Figure 44.
Figure 44. Outer eccentric rod

25

6.3 Inner eccentric rod
The inner eccentric rod is remarkably similar to the outer eccentric rod in both form in
function, but it is not slanted in the center like the outer rod, so that the outer rod will easily pass
over it when the eccentric components of the assembly rotate. To ensure a proper fit and save
time, it was therefore created from the same file as the outer eccentric rod, but with a
modification made to the loft in the center to cause the rod to be straight. It is also composed of
cast alloy steel. The completed part is displayed in Figure 45.
Figure 45. Inner eccentric rod
6.4 Eccentric rod cap
The eccentric rod is designed to fit snugly against the outer eccentric rod and the inner
eccentric rod, and includes holes for being bolted in the same locations. For this reason, the first
part of the design was again copied from the outer eccentric rod, with the top arm and handle
pieces removed and the piece inverted physically to create the bottom of the ellipse. An extrusion
was added to the bottom to create the extra hump. Fillets were also used to create the appropriate
shape. It is composed of cast alloy steel. The completed part is displayed in Figure 46.
Figure 46. Eccentric rod cap

26

6.5 Link plate
The link plate was created with a single simple extrusion and contains three equally sized
holes. Two of these pieces are used in the full assembly, one on either side of the link screw
bearing. Three machine screws bind the two link plates together with the link screw bearing
between them and screwed into the center hole. It is composed of cast brass. The completed part
Figure 47. Link plate
6.6 Link screw bearing
The link screw bearing is also created with a single extrusion consisting of two nested
circles. It sits between the two link plates in the assembly and lies within the slot at the top of the
link, allowing it to roll along the path created by the curvature of the slot. It is composed of
brass. The completed part is displayed in Figure 48.
Figure 48. Link screw bearing

27

7. Handle Sub-Assembly Parts
7.1 Control lever
The control lever was created starting from a boss extrusion to create the bottom segment
of the arm, including two holes for attachment points. The second segment of the arm was
created using a loft, allowing it to shift axes slightly. The third segment, which contains the
circular hole and rectangular slot, was created by making a boss extrusion with the circular hole
and extruding it out in both directions from the top edge of the lever, then using a cut-extrude to
create the slot. The top portion, with the blade-like piece, was created using a boss extrude. It is
Figure 49. Control lever
7.2 Control lever pin
The control lever pin is in the running for simplest part in this design, consisting of a
single circular extrusion. It is used to pin the bottom of the grip to the control lever. It is
Figure 50. Control lever pin

28

7.3 Grip
The grip is a deceptively simple-looking piece. Its base was created with a pair of boss
extrusion and the shell command. The hole at the bottom allows it to nest around the control
lever at the top. Its "fin" piece was created through a pair of extruded surfaces, binding the edges
of the shape, and a boss extrusion. The very top portion above the hole was created with another
boss extrusion, and the hole itself was created with a cut-extrude. The hole in the top is to be
joined with the handle leaf spring piece by the handle spring pin in the sub- assembly. The metal
spring piece presses against the control lever, forcing the grip to rotate outwards relative to the
control lever but able to be pressed inwards by applying force to the spring piece. It is composed
of cast alloy steel. The completed part is displayed in Figure 51.
Figure 51. Grip
7.4 Handle leaf spring
The handle leaf spring is created from a boss extrusion along its side with a cut-extrude to
create the hole. The hole is pinned to the top of the grip by the handle spring pin in the sub-
assembly and the bottom presses against the control lever, forcing the grip outwards. It is
Figure 52. Handle leaf spring

29

7.5 Handle spring pin
The handle spring pin joins the handle spring piece and the grip. The handle spring pin is
composed of a single revolution about a central axis to create a mushroom-like shape. It is made
of cast iron steel. The completed part is displayed in Figure 53.

Figure 53. Handle spring pin
7.6 Suspension link
The suspension link is designed to join the handle sub assembly to the rest of the main
assembly through the link assembly. To create it, first a boss extrusion was made for the flush
hollow cylinder on one side./ Using its top plane as the sketch plane , another cylinder was made
on the opposite side and extruded in two directions with distances of .375in in one direction
downwards and .5in upwards relative to the sketch plane. The bar in the center was created on
the same plane and blind extruded downwards. Fillets were added as a final step. The part is
Figure 54. Suspension link
III. Mechanical Design: Assembly
1. Case Sub-Assembly
To begin the case sub-assembly, all necessary fasteners were downloaded from
McMaster-Carr's website. The required fasteners were three .25in 28x 1.5in round head machine
screws, a 1in 20 thread hex nut, and four .875in 14x 2.25in hex head bolts.
The first step was to insert a component for the case as the starting point, as shown in
Figure 55. For the sake of explanation, the transparency feature has been utilized on the case to
show the inside details.

30

Figure 55. Case sub-assembly step 1
The second step was to add two copies of the component for the bushing. Both bushings
were mated concentric and coincident with the corresponding holes on the case, as shown in
Figure 56.
The third step was to insert a component for the throttle support. This component was
mated concentric and coincident with the corresponding surfaces on the case, as shown in Figure
57.

31

The fourth step was to add two copies of the component for the main bearing cap. Both of
these components were mated to have their bottom faces coincident with the corresponding faces
of the case, allowing them to rest neatly over the top of the bushings, as shown in Figure 58.
The first fastener added to the assembly was the 1 in 20 thread hex nut, which was added
to the end of the throttle support and mated coincident and concentric with relevant circles of the
threads on the throttle support, as shown in Figure 59. It was also mated to be parallel with the
top plane to prevent the screw from being torqued any further.

32

The next step was to fasten the main bearing caps to the case by using the four .875in 14x
2.25in hex head bolts. The bolts were mated to have the bottom surfaces of the heads coincident
with the flat surfaces of the main bearing caps, and concentric with the relevant circles of the
threads mated to the holes for the fasteners, as shown in Figure 60.
The final step was to fasten the throttle support to the case using the three .25in 28x 1.5in
round head machine screws. Again, the bottom surfaces of the screw heads were mated to be
coincident with the flat surfaces of the throttle support and the screw thread circles were
concentric with the holes in the throttle support, as shown in Figure 61.

33

The full case sub-assembly, with transparency still turned on for literal clarity, is shown
in Figure 62.
Figure 62. Case sub-assembly
2. Powertrain Sub-Assembly
To begin the powertrain sub-assembly, all necessary fasteners were downloaded from
McMaster-Carr’s website. The required fasteners were two 0.2500-28-N acorn nuts, two 0.25-
20x2.75x.75-N round head bolts, two 0.2500-20-D-N hex nuts, two 0.375-24x1x1-N hex bolts,
and two 0.375 regular lock washers.
The first step was to mate the two crank shaft halves and the crank pin together, using
three concentric and two coincident mates, as shown in Figure 63.
Figure 63. Powertrain sub-assembly step 1
The next step was to mate the flywheel to the left end of the subassembly. This was done
with one concentric and one coincident mate, as shown in Figure 64.

34

Next, the connecting rod was attached. This was done with four width mates, two parallel
mates, and three coincident mates, as shown in Figure 65.
After attaching the connecting rod, the next priority was to connect the hinge body. The
pin fit concentric into the top of the connecting rod and the hinge body itself, and the only other
mate required was to set the top to be parallel with the Top Plane. The parallel mate was required
for the piston to move correctly. This portion is shown in Figure 66.

35

Finally, the two collar halves were mated concentrically to the crank shaft, and a width
mate was used between the flywheel and the nearest cylindrical extrusion. Then, the fasteners
were added to all components, as shown in Figure 67.
The full powertrain sub-assembly is shown in Figure 68.
Figure 68. Powertrain sub-assembly

36

3. Cylinder Sub-Assembly
To begin the cylinder sub-assembly, all necessary fasteners were downloaded from
McMaster-Carr’s website. The required fasteners were seven .625 in 11x 1.25in hex bolts, two
.4375in 20x 0.75in hex nuts, and one .4375in 20x 3.5x 1.125 in hex bolt.
The starting component of the assembly was chosen to be the main cylinder, as it was the
part that had the most connections to it. For simplicity of the setting forming this sub-assembly,
the part is fixed. To being the assembly the cases were placed on to the respective locations,
using concentric circle mate on the bolt hole location, this mate ensured no relative rotation.
Then a coincident mate was used to ensure no translation motion in the normal direction. Then
the exhaust valve was inserted into the top slot of the cylinder with a coincident and concentric
circle mate. During the concentric circle mate, the box to lock rotation was checked, as this valve
is actually screwed into place, as shown in Figure 69.
Figure 69. Cylinder sub-assembly step 1
To continue the assembly, the cylinder packing parts were mated to the bottom of the
cylinder. First, the top of the packaging was mated with concentric and coincident mates, then
the packaging was inserted into the hollowed out portion of the top. This portion is shown in
Figure 70.

37

The studs were then inserted into the top, using concentric circle and coindent mates.
This fixed the top of the packaging into the cylinder. Next the bottom was slid onto the the studs
using concentric circle and coindent mates. This is shown in Figure 71.
The next phase of the assembly was to connect the second packaging sub system. This
was connected to the bottom of the cylinder using similar connections as the exhaust valve. This
sub-system involved the same aspects as the packaging system above. It consisted of a top,
packaging, and a bottom. These steps are shown in Figure 72 and Figure 73.

38

The next part mated to the assembly was the ratchet-like speed indicator. It was mated
using a concentric circle with the smaller bolt hole of the valve cap. Subsequently, the cylinder
face of the indicator was made coincident with the face of the valve cover, as shown in Figure
74.
The drain cock was the next part to be mated to the assembly. The drain cock was mated
using the concentric circle with the locked rotation option check, then made coincident with the
side of the cylinder. The drain lever was mated with a concentric cirlcle with the handle and the
opening of the drain cock. The ball of the lever was then made coincident with the inside of the
of the drain cock, as shown in Figure 75.
The last major components to mated to the assembly were the pressure valves. This
involved inserting the threaded pipes into the two slots on the side of the cylinder. This was done
using concentric circles again locking rotation and coincident mates. The two valves were then
inserted into each respective pipe, again with coincident and cocnetric circle mates, as shown in
Figure 76.

39

The last phase of this sub-assembly was to apply fasteners to all of the bolt holes, studs,
and valves. The final cylinder sub-assembly is shown in Figure 79.
Figure 79. Cylinder sub-assembly
4. Valve Sub-Assembly
To create the valve sub-assembly, first all necessary fastener files were downloaded from
McMaster-Carr's website. The fasteners required for this assembly were eight .50 in 20x 1.5 in
hex bolts and a .375 in 24 thread hex nut.
The first components inserted for the sub-assembly were the valve rod actuator and the
valve rod. The valve rod actuator's hole was mated to be concentric with the outside of the valve
rod, allowing the valve rod actuator to slide freely along the valve rod, as shown in Figure 80.

40

Figure 80. Valve sub-assembly step 1
The next component added in was the slide valve. The indentation surface at the bottom
of the slide valve was mated to be coincident with the top surface of the valve rod, with the
circles at the edge of the valve rod and the indentation concentric, as shown in Figure 81. The
slide valve has transparency turned on for this image for the sake of illustration. The valve rod
actuator's flat front surface is also mated to be parallel with the front plane, preventing the piece
from rotating about the axis created by the slide valve.
The next component added to the assembly was the sliding block front piece. This
component was mated to have its bottom inner surface cut concentric with the main portion of
the actuator and with the flat surfaces around the fastener holes parallel to the front plane, again
to prevent rotation, as shown in Figure 82.

41

The sliding block rear piece was the next component inserted into the assembly. The
rounded surface inside was mated to be concentric with the valve rod actuator, once again, and a
single point at the edge of the semicircle on one end of the rear piece was mated with the
corresponding point at the end of the front piece, ensuring that the pieces would move together
as shown in Figure 83.
The last major component added to the assembly was the Stephenson valve fastener. The
bottom surface of the hex nut piece was mated to be coincident with the top surface of the valve
rod actuator, and the circle at the edge of the hole was mated to be concentric with the valve rod,

42

The first fastener added to the sub-assembly was the .325in 24 thread hex nut, which was
added to the bottom end of the valve rod. It was mated to have its hole concentric with the valve
rod, and its bottom surface coincident with the bottom surface of the valve rod, as shown in
Figure 85.
Finally, eight .5in 20x 1.5in hex bolts were inserted into the relevant holes on the sliding
block front piece and rear piece. The bottom surfaces of the heads of each bolt were mated with
the top surfaces of the front and rear pieces, and the bottom circles of the threads were mated
with the relevant holes in the front and rear pieces. All of the bolts rotations were locked to
ensure that they were equally torqued, as shown in Figure 86.
The full valve sub-assembly is shown in Figure 87.

43

Figure 87. Valve sub-assembly
5. Piston Sub-Assembly
The first step was to mate two of the piston rings concentrically to the piston, into their
corresponding revolved cut features, as shown in Figure 88.
Figure 88. Piston sub-assembly step 1
Next, the piston rod was mated concentrically to the underside of the piston and
coincident to the inner face, as shown in the full piston assembly in Figure 89.

44

Figure 89. Piston sub-assembly
6. Link Sub-Assembly
To create the link sub-assembly, first all necessary fastener files were downloaded from
McMaster-Carr's website to ensure that standard fasteners would be used in all cases to most
accurately replicate real world construction while avoiding collision issues that might be caused
by approximation. The fasteners required for this assembly were a .25in-28 machine threaded
hex nut, a .25in-28x1.25in slotted head machine screw, a .25in-20x1.75in round head bolt, a
.25in-20 hex nut, .25in-28x4in hex bolt, .25in-28 hex nut.
The first piece of the assembly was the link, as shown in Figure 90.
Figure 90. Link sub-assembly step 1
First, a component of the outer eccentric rod was inserted and mated coincident to the
outside hole on the link part, as shown in Figure 91.

45

Next, a component of the inner eccentric rod was inserted. It was mated coincident to the
inside hole on the link part opposite the outer eccentric rod, as shown in Figure 92.
The outer and inner eccentric rods were fastened to the link using two .25in 20x1.75in
round head bolts and two .25in 20 hex nuts, as shown in Figure 93. The hex nuts should be on
the side away from the outwards bend of the outer eccentric rod, mated using a series of
concentric and coincident mates based on the circles of the bolts and the nuts.

46

Subsequently, two copies of the eccentric rod cap part were added to the assembly, and
mated with the appropriate ends of the eccentric rods, using the holes to align the parts. The
fillets should match properly if alignment is achieved, as shown in Figure 94.
The eccentric rod caps were attached to the rest of the assembly using four .25in 28x4in
hex bolts and four matching 25in 28x4in hex nuts through the holes on the eccentric rod pieces,
as shown in Figure 95 and Figure 96. Again, this was accomplished by utilizing a series of
concentric and coincident mates with the eccentric rod pieces.
Figure 95. Link sub-assembly step 6, top

47

Figure 96. Link sub-assembly step 6, bottom
Next, a component for the link screw bearing was added. It was mated flush with the
edges of the link and tangent to the bottom surface of the slot so that it will slide along the slot,
Next, two copies of the link plate were added, one on either side of the screw bearing.
The center holes of the plate were mated coincident with the center hole of the screw bearing,
allowing the two side holes to be on either side, as shown in Figure 98. The two link plates were
also mated parallel to one another so that they will rotate together as necessary.

48

Three .25in 28x1.25in slotted head machine screws and three .25in 28x1.25in slotted
head machine threaded nuts fasten the two link plates and the link screw bearing together. The
fasteners through center of the link screw bearing and plates should be opposite of the rest of the
surrounding fasteners to create added stability and resistance to failure, as shown in Figure 99.
The final sub-assembly is shown in Figure 100.
Figure 100. Link sub-assembly

49

7. Handle Sub-Assembly
To create the handle sub-assembly, first all necessary fastener files were downloaded
from McMaster-Carr's website to ensure that standard fasteners would be used in all cases to
most accurately replicate real world construction. The fasteners necessary for this sub-assembly
are the .25in 20x1.5in round head bolt, .25in 20x2in round head bolt, and a .25in 20 hex nut.
First, the control lever arm began the assembly, as shown in Figure 101.
Figure 101. Handle sub-assembly step 1
A component was inserted for the grip. The holes on the grip were mated concentric with
the corresponding holes on the handle so that it fits snugly around it, as shown in Figure 102.

50

A component for the control lever pin was inserted next. It was mated concentric and
coincident with the corresponding holes on the control lever grip to fasten the handle and grip to
one another, as shown in Figure 103.
A component for the handle spring pin was inserted next. It was mated such that it is
coincident with the surface at the top of the grip and concentric with the corresponding hole. The
bottom edge was mated with the side surface of the handle, forcing the grip to rotate outwards
slightly, as shown in Figure 104.
Next, a component for the handle spring pin was inserted. It was mated it such that it is
coincident with the surface of the spring pin and concentric with the hole, fastening the handle
and spring together as shown in Figure 105.

51

Next, a component for the suspension link was added. This is an asymmetric piece, so
caution must be used when adding it to the assembly. The surface that is flush with the
rectangular beam connecting the two cylinders is mated flush with the surface of the handle, and
the circle at the edge of the hole of the cylinder is mated coincident with the hole on the handle,
The suspension link is fastened to the handle using the .25in 20x1.5in bolt and a
corresponding .25in 20 thread hex nut by using coincident and concentric mates with the
surfaces of the parts and the fastener holes, as shown in Figure 107. The bolt should be on the
side with the suspension link, with the hex nut on the side with the handle.

52

A 25in 20x2in bolt and a corresponding .25in 20 thread hex nut are attached in the same
orientation to the other side of the suspension link for later addition to the main assembly.
Threads should protrude to allow room for other components, as shown in Figure 108.
The completed handle sub-assembly is shown in Figure 109.
Figure 109. Handle sub-assembly

53

8. Final Assembly
The final assembly began with the case sub assembly, as shown in Figure 110.
Figure 110. Final assembly step 1
The next step was to add the powertrain sub assembly. For the crank shaft, a width mate
was used to secure it equidistant from the two case walls that surround it. A parallel mate was
used between the top face of the powertrain sub assembly and the Top Plane so that the piston
would move once inserted. Furthermore, the cylindrical hole the piston was inserted into had to
move only in the vertical direction (y-axis), which was accounted for by the double hinge system
present in the subassembly, as shown in Figure 111.
The link sub assembly was added next. The link arms were mated concentrically to the
two corresponding cylindrical bodies on the crank shaft. Additionally, the outer arm’s outer-most

54

face was mated coincident to the outer face of its corresponding cylindrical body. This
attachment is shown in Figure 112.
The handle sub assembly came next. This and the link sub assembly control the opening
and closing of the valve which steams enters the cylinder through. It was attached using
concentric and coincident mates, to the case and the link sub assemblies, as shown in Figure 113.

55

The valve sub assembly was then mated to both the case and the link sub assemblies. The
protruding cylinder in the valve subassembly was mated concentrically to the sliding follower in
the link sub assembly. Therefore, the motion of the follower determines the displacement of the
rod inside the valve sub assembly. This is shown in Figure 114.
The last component mated to the assembly was the cylinder sub assembly. In actuality,
the cylinder would be attached to a boiler at the top, and the valve sub assembly would open and
close a valve inside the cylinder sub assembly to control the amount of steam that enters the
engine. The steam would then enter the vertical portion of the cylinder sub assembly and push
the piston downward. The cylinder sub assembly was mated using concentric and coincident
mates, as shown in Figure 115.
An exploded view of the final assembly is shown in Figure 116. The final, rendered
assembly is shown in Figure 117.

56

Figure 116. Full assembly, exploded view
Figure 117. Final assembly, fully rendered

IV. Mech
T
included
were stan
be machi
mass pro
aligned to
T
SolidWo
was stuc
analysis
moved fr
V. Mech
T
which ca
powertra
allow the
through
contains
hanism Mo
The assembly
gray cast ir
ndard fasten
ined, and th
operties analy
o the origin
The use of
rks. Withou
k in a static
SolidWorks
reely. The m
hanism Kine
The case sub
an be secure
ain and pisto
e piston to m
the utilizati
valves to co
del Mechan
y is made o
ron, aluminu
ers available
e combined
ysis of the f
of the case s
sub-assemb
ut care given
c position, b
s needed to
mass properti
Figure
ematics
b-assembly t
ed to the sur
on cylinder r
move prope
ion of an a
ontrol the ste
nics
out of prima
um bronze,
e from McM
mass of the
full assembly
sub-assembly
lies was cr
n to how th
but after brea
perform be
es of the fina
118. Mass p
that houses
rface of a m
reside. The p
erly, doing m
ctuator. The
eam as well
57
arily cast all
and cast br
Master-Carr. T
e entire asse
y used the d
y.
rucial to th
he sub-assem
aking the as
ecame much
al assembly
properties o
the entire st
marine vesse
piston's oscil
mechanical w
e case is to
as a ratchet
loy steel; ho
ass. The fas
The parts us
embly is app
default coord
e functiona
mblies were
ssembly into
h simpler, an
are shown in
of full assem
tructure is d
el for use. In
llation is con
work by har
opped with
t bar to creat
owever othe
steners used
sed in the ass
proximately
dinate system
ality of the
separated, t
o rigid bodie
nd as a resu
n Figure 118
mbly
designed to
nside of the
ntrolled by e
rnessing the
a cylinder
te notches fo
er materials
d in the asse
sembly wou
321 pounds
m, with the o
CAD mod
the full asse
es, the nume
ult, the asse
8.
be a static
sub-assemb
eccentric dis
e power of s
assembly, w
or controllin
used
embly
uld all
. The
origin
del in
embly
erical
embly
piece
bly, a
scs to
steam
which
ng the

58

handle sub-assembly. The handle sub-assembly is also fastened to the throttle on the case, and by
moving the spring-loaded handle it is possible to control the entire machine by moving an
eccentric link sub-assembly, which is designed to fit snugly around the eccentric discs on the
powertrain.
VI. Structural Analysis
Because the mechanical movement of the piston is the form of work performed by the
steam within the steam engine, it seemed appropriate to conduct a motion analysis of the piston,
relative to the bottom face of case. In any reasonable application, the case would be fixed to a
surface of the location where it was to be utilized, and so utilizing this location as a datum
represents a reasonable approximation of the piston's relative motion. The linear displacement of
the piston relative to the bottom face of the case is shown in Figure 119. The piston's total
displacement is sinusoidal in nature as a result of the eccentricity of the plate to which it is
attached to the rod.
Figure 119. Linear displacement of piston relative to bottom of case
The linear velocity of the piston in the y-direction was also analyzed, and this is shown in
Figure 120. This graph appeared to have a slight bias and peaked at the location of the change in
concavity in the previous graph of the linear displacement.
Figure 120. Piston linear velocity (y-component)

59

Additionally, the linear acceleration in the y-direction was analyzed, and its graph is
shown in Figure 121. The acceleration had a much flatter peak at the top, with relatively narrow
valleys occurring at the changes in concavity of the velocity graph, as predicted by calculus.
Figure 121. Linear acceleration (y-component)
A structural analysis was performed on the powertrain sub-assembly. For the sake of this
analysis, a torque of 500 N m was applied on the shaft adjacent to the flywheel. The stress results
of this simulation are shown in Figure 122. The von Mises stresses experienced by the flywheel
were greatest at the smallest end of the shaft, near where the torques were applied. The stresses
experienced by the eccentric plates and wheel were very low comparatively speaking.
Figure 122. Stress on flywheel

60

VII. Conclusion
The parts created for this marine steam engine provided an opportunity to utilize all of
the techniques explored in this course, including but not limited to boss extrusions, extruded
cuts, revolved extrusions and cuts, lofts, sweeps, fillets, and patterns. By utilizing standard
fasteners, it was possible to properly secure all of the pieces together to more accurately simulate
what a real steam engine might have looked and behaved like, including conducting a motion
analysis on the piston relative to the case of the steam engine. Though steam engines have
largely fallen out of favor in modern applications due to their inherent shortcomings, such as
their weight, the dangers of using compressed steam as an operating fluid, and their inefficiency,
steam engines were critical in the Industrial Revolution, and in this instance served as a model
for understanding machine design. By modeling an antique steam engine it was possible to
simulate a number of complex interacting parts that are designed to utilize properties of
thermodynamics and fluid mechanics to perform mechanical work. In this way, this final project
also served as both a reminder of the history of modern engineering development and an
application for several years' worth of engineering coursework in a wide variety of courses,
allowing for knowledge integration both between individuals and over time.
VIII. References
[1] Wikipedia, 2015, "Steam Engine." http://en.wikipedia.org/wiki/Steam_engine
[2] McMaster-Carr, 2015, "McMaster-Carr Online Catalogue." http://www.mcmaster.com/
[3] Wikipedia, 2015, "Marine Steam Engine." http://en.wikipedia.org/wiki/Marine_steam_engine

Antique Marine Steam Engine Solidoworks Project

Recommended

Recommended

More Related Content

Similar to Antique Marine Steam Engine Solidoworks Project

Similar to Antique Marine Steam Engine Solidoworks Project (20)

Antique Marine Steam Engine Solidoworks Project