1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                         © by maxon motor...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                        ©...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                              © by maxon ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010                                         ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                © by m...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                   © b...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                               © by ma...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010                                      ...
3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010                                        © by max...
3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010                                         © by ma...
3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010                                            © by...
3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010                                                ...
3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010                                                ...
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Maxon dc motor sizing made easy presentation english version march 2010
Upcoming SlideShare
Loading in...5
×

Maxon dc motor sizing made easy presentation english version march 2010

593

Published on

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
593
On Slideshare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
29
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Maxon dc motor sizing made easy presentation english version march 2010

  1. 1. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Drive Selection: What is it all about? The context of motor selection Application and situation analysis Extracting key load parameters Seminar at Electromate © 2010, maxon motor ag, Sachseln, Switzerland Systematic selection process: Step 1 Step 1 overview situation power communication ambient condition step 2 step 3 step 4 step 5+6 step 7+8 load drive gear- motor type sensor head winding controller Book: Chapter 3 Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  2. 2. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Gain an overview mechanics operating mode power motion profile control concept control accuracy working points boundary conditions Drive system as a black box environment temperature, atmosphere impacts, vibration electrical power … boundary conditions current dimensions task voltage service life set values … commands emissions electro magnetic heat noise … mechanical power force, torque quality, accuracy velocity, speed resolution mech. play Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  3. 3. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Mechanical drive concept Drive design: linear – rotation Drive elements and coupling with load relative position of motor and load – e.g. bridge a distance with a belt Mechanical drive concept: Bearing Support of all the forces – Eccentric drive, cam, pump – rack guidance – pulley bearings of conveyors, cranes and belt drives Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  4. 4. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Operating modes continuous (S1) load time short term (S2) working cycles intermittent (S3) Control concept Controlled variable – torque, current – speed, velocity feedback sensor – position Controlled range, accuracy? – position resolution – speed stability What kind of communication? – communication with higher level host system – set value range: 0 … 5 V or -10 … +10 V – inputs and outputs (homing, temperature monitoring, …. Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  5. 5. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Task and control accuracy gearhead, command controller motor load drive control loop sensor The accuracy of control is the combined result of all components in a drive system! – resolution, precision – signal amplification, control parameter – phase shifts, time shifts, backlash, mech. play Particular boundary conditions dimensions – length, diameter service life – specific depending on load cycle, ambient conditions and application – given as service hours or numbers of working cycles – limited by the weakest component temperature, atmosphere – can influence the achievable power and service life noise, vibration – specific depending on load cycle, mounting and ambient conditions, application – influences on service life Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  6. 6. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Systematic selection process: Step 2 Step 1 overview situation power communication ambient condition step 2 step 3 step 4 step 5+6 step 7+8 load drive gear- motor type sensor head winding controller Book: Chapter 4 Working points Pair of – torque and speed – force and velocity standard representation: (x,y) = (M,n) or (F,v) speed n velocity v deceleration acceleration dwell torque M force F Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  7. 7. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Working point and motion profile n 1 2 3 4 1 t n extreme working point 2 4 3 1 M (M1,n1) acceleration friction and acceleration (M2,n2) const. speed friction only (M3,n3) deceleration friction helps during deceleration (M4,n4) dwell depending on friction Motion profiles general parameters – duration ∆ttot – max. velocity vmax – distance ∆s symmetrical triangular profile – for fast motions – minimum acceleration 3/3 profile – minimum power – thermally advantageous Book: P. 24/25 Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  8. 8. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Operating modes continuous operation (S1) – acceleration and deceleration can be neglected – constant load – duration: longer than all thermal time constants of the system in thermal equilibrium: constant temperatures typically: several minutes up to hours Tmax temperature load time Operating modes short term operation (S2) – very short operation time only elements with a correspondingly short time constant can heat up – long dwell times drive can cool down completely Tmax temperatur load time Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  9. 9. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Operating modes cyclic operation (general case) – load profile to be repeated permanently with relatively short dwell times duration of a cycle: typically up to several seconds – thermal equilibrium is reached on average only temperature variations – effective load (RMS) is an important key parameter MRMS = 1 t tot (t1M1 + t 2M2 + t 3M3 + ... 2 2 2 ) Tmax temperature load time Operating modes intermittent operation (S3) ON - OFF M t on RMS = ⋅ Mon – special case of cyclic operation t on + t off temperature • winding • housing 1s 10s 100s 1000s 10000s 10s 100s 1000s Time Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  10. 10. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Friction forces difficult to evaluate – many influencing factors: state of the interface layer normal force FN – varies upon time: ageing effects moving – typical coefficients of friction from direction tables (book p. 30/31) body tion brica r, lu laye face is friction force FN in te r bas FR = µ ⋅ FN estimation formula for ball bearings: MR = 0.5 ⋅ µR ⋅ F ⋅ d Acceleration of mass inertias additional force / torque ∆v Fa = m ⋅ a = m ⋅ necessary ∆t – basic equations for ∆ω π ∆n translation / rotation Mα = J ⋅ α = J ⋅ = J⋅ ∆t 30 ∆t mass inertias – translation: mass m – rotation: moment of mass inertia JX with respect to axis x Jx = r 2 ⋅ dm m 2 – example cylinder: Jx = ⋅r 2 Book: P. 40ff Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  11. 11. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Constant forces, preloading forces Example spring preload Example gravity speed n velocity v deceleration acceleration dwell torque M without gravity force F with gravity Determination of forces / torques simple measurements – precision needed: 5-10% – e.g. by means of pulleys and spring balances estimation of friction torques by means of friction coefficients µR using a motor for torque determination – by means of a current measurement and the torque constant kM – in original conditions – Suitable current measuring tool M = kM ⋅ I Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  12. 12. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Key load data for characterization average effective load (RMS) maximum load duration of a load cycle duration of the maximum load max. velocity or speed required position resolution required speed accuracy Load characterization dominating constant load – typically in cases of high friction – maximum forces exceed RMS load by less than 20% – maximum forces applied during short terms only => selection based on RMS load is sufficient dominated by peak load – typically in cases of highly dynamic drives with high acceleration – RMS value of load very small (< 50 % of maximum load) => selection based on maximum load values general case without domination of one load type Remark: Acceleration and friction in the mechanical drive are not taken into consideration yet! Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  13. 13. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Systematic selection process: Steps 3 & 4 Step 1 overview situation power communication ambient condition step 2 step 3 step 4 step 5+6 step 7+8 load drive gear- motor type sensor head winding controller Book: Chapters 5&6 Mechanical transformation by means of drive elements – also in series characteristic variables – reduction i – efficiency η – mass inertias – backlash transformation equations bearings Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  14. 14. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Screw drives speed 60 nin = ⋅ v out p torque p Fout Min = ⋅ 2π η torque for acceleration mout + mS p 2 π ∆nin Min,α = Jin + JS + ⋅ η 4π 30 ∆t α 2 Spindle drives spindel type: trapezoidal, metric, ball screws spindle type has influence on – efficiency, heating – possible working cycles, ON time – costs – accuracy, play, backlash – maximum load – life – application: actuators or positioning units Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  15. 15. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Gearhead stage speed nin = nout ⋅ iG torque Mout Min = iG ⋅ ηG torque for acceleration Jout + J2 π ∆nin Min,α = Jin + J1 + ⋅ iG ⋅ ηG 2 30 ∆t α maxon gear operation at high torques and low speeds 2 standard types: GS: spur gearhead GP: planetary gearhead lower power density high power density material options – plastic: lower power, lower costs – ceramic: higher power, longer life bearing options – ball bearing: standard for larger planetary gears – sleeve bearing: standard for GS and small GP Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  16. 16. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Most important gearhead data reduction - absolute reduction efficiency – as a function of torque gearhead limits – max. continuous torque (output) – intermittent torque (short-term = 1s) – max. input speed – temperature (lubrication) backlash load on bearings Operating range diagram recommended gear input speed output defines max. output speed speed n nmax,out = max,in i continuous intermittent operation operation output torque M Mcont Mmax Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  17. 17. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Systematic selection process: Steps 5 & 6 Step 1 overview situation power communication ambient condition step 2 step 3 step 4 step 5+6 step 7+8 load drive gear- motor type sensor head winding controller Book: Chapter 7&8 DC motor designs DC motors BLDC motors conventional, with iron core slotless slotted external rotor slotted coreless internal rotor Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  18. 18. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Systematic selection process: Steps 7 & 8 Step 1 overview situation power communication ambient condition step 2 step 3 step 4 step 5+6 step 7+8 load drive gear- motor type sensor head winding controller Book: Chapter 9 Controller: The Heart of the Drive System Communication Power Supply – Host, Master – cont. current – I/O – max. current controlled quantity – voltage Controller power digital – analogue Sensor … – measured quantity – resolution Motor – motor type Gearhead, mech. drive – power – reduction ratio – backlash Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  19. 19. 1. Drive selection: What is it all about?maxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Motion Control System Application Program Cycle (e.g. 5 ms) 11001.. command Path Generator Pos Position Set Value t Position/Speed Actual Control loop Position I Motor with Encoder Current Set Value and Drive t Current Actual Control loop Current PWM Clock Clock duty (e.g. 1 kHz) (e.g. 10 kHz) Driver, Power cycle Amplifier PWM (e.g. 50 kHz) Sensors Set value Output Actuator Measurement Feedback DC Tacho Incremental Encoder Resolver IxR Hall Sensor Speed ∆Pos/∆t Position Direction Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  20. 20. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 DC and BLDC Motors with Permanent Magnets Design, design variants Commutation: Graphite and precious metal brushes Brushless commutation Seminar at Electromate © 2010, maxon motor ag, Sachseln, Switzerland DC motor designs conventional, slotted e.g. Dunker motor coreless e.g. maxon Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  21. 21. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Coreless maxon DC motor (RE 35) self-supporting press ring commutator- winding shaft plate ball bearing brushes el. connections flange housing (magn. return) ball bearing commutator permanent magnet press ring (in the centre) Advantage coreless: no cogging no soft magnetic teeth to interact with the permanent magnet smooth running even at small speeds less vibration and noise any rotor position can be controlled in a simple way no nonlinear control behaviour Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  22. 22. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Advantage coreless: no iron losses no iron – no iron losses constant magnetization high efficiency, up to above 90% low no load current, typical < 50 mA no saturation effects in the iron core Even at the highest currents the produced torque remains proportional to the motor current. stronger magnets = stronger motors compact design small rotor inertia Advantage coreless: small inductance less brush fire – commutation: open and close a contact on an inductive load higher live expectancy less electromagnetic emissions easier to suppress interferences: – capacity between connections – ferrite core at motor cable but fast reaction of the current – problems in combination with pulsed supply (choke needed) Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  23. 23. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 maxon DC motor: Variants RE-Motor with NdFeB magnet graphite brushes ball bearing A-max-Motor with AlNiCo magnet precious metal brushes sintered sleeve bearing Commutation process _ + + 1 4 1 5 2 5 2 6 3 6 1 3 7 7 2 4 7 6 4 1 3 5 1 5 4 5 2 6 2 6 3 7 3 7 4 _ 1 4 Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  24. 24. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 DC commutation systems graphite graphite brush with 50% copper copper reduces contact and brush resistance graphite acts as lubricant spring precious metal bronze brush body with plated silver (with palladium) contact area silver copper commutator small contact and brush resistance (50mΩ) CLL for extended service life Precious metal brushes: CLL the problem arc production commutator wears off after short circuit commutator solution - capacitors between neighbouring C commutator segments C - energy is deviated into capacitor: C no arcs produced CLL disc RS Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  25. 25. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 DC commutation: pros and cons graphite precious metal well suited for high currents and well suited for smallest currents current peaks and voltages well suited for start-stop and well suited for continuous reversed operation operation bigger motors smaller motors very low friction and noise higher friction, higher no-load low electromagnetic emission currents favourable price not well suited for small currents more audible noise and not well suited for high currents electromagnetic emission and current peaks more expensive not well suited for start-stop operation maxon DC motor: service life service life life influencing factors no general statement possible the electric load: higher currents average conditions: 1000 - = higher electric wear (arcing) 3000 hours speed: higher speed = higher under extreme conditions: less mechanical wear than 100 hours type of operation: reversed under favourable conditions: operation = reduced service life more than 20000 hours temperature humidity with graphite brushes use graphite brushes and CLL (with precious metal ball bearings for extreme brushes) enhances service life operating conditions load on shaft (bearings) Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  26. 26. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Brushless DC motor names: EC motor, BLDC motor motor behavior similar to DC motor – design similar to synchronous motor (3 phase stator winding, rotating magnet) – the powering of the 3 phases according to rotor position main advantages: higher life, higher speeds slotless windings – similar advantages as coreless DC motors – no magnetic detent, less vibrations the more attractive, the smaller the costs and size of electronics maxon EC motor / brushless DC motor magn. return: preloaded laminated iron stack ball bearings PCB with Hall sensors control magnet shaft housing 3 phase knitted balancing rings maxon winding rotor el. connections winding and Hall sensors (permanent magnet) Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  27. 27. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 maxon EC motor design variants slotless slotted external rotor features in common – rotating permanent magent made of NdFeB – 3 phase winding in the stator (3 winding connections) – preloaded ball bearings slotted – electronic commutation internal rotor maxon EC motor: Coreless design design with coreless maxon winding – internal rotor with 1 or 2 pole pair maxon EC motor – many types: e.g. short – long, sterilisable, integr. electronics, … – typically for high speeds maxon EC-max – Philosophy: reliable EC motor at reasonable price maxon EC-powermax – Philosophy: the strongest possible motor Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  28. 28. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 maxon EC motor: Slotted design maxon EC-i – Philosophy: strong EC Motor at attractive price – dynamic motor, high cogging torque – slotted winding, internal rotor – several magnetic pole pairs flat maxon EC motor – Philosophy: flat EC Motor at an attractive price – slotted winding, external rotor – more than 4 magnetic pole pairs – relatively high torque but limited speed and dynamics DC and EC motor: Comparison maxon motor family RE (DC) EC EC-max (20 – 45 mm) EC-powermax EC-flat EC-i 40 000 min-1 5 W/cm3 2 mNm/cm3 10 ms max. speed power density torque density mech. time const. (min-1) (W/cm3) (mNm/cm3) (ms) Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  29. 29. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Interaction of rotor and stator current distribution in phases – 3 phases 3 phases – 6 possible current distributions winding – 6 winding magnetic field directions rotated by 60° – commutation every 60° field produced by winding Electronic commutations systems common goal: Applying the current to get the maximum torque perpendicular magnetic field orientation of - rotor (permanent magnet) - and stator (winding) knowledge of rotor position with respect to winding block comm.-Typ sine rotor position sensorless hall sensors encoder (+ HS) feedback DECS external DES DEC family electronics EPOS Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  30. 30. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Block commutation rotor position from Hall sensor signals φ north control magnet south Hall sensor 1 1 0 0 0 1 1 0 1 1 1 0 0 0 0 0 0 1 1 1 0 0° 60° 120° 180° 240° 300° 360° EC-max and EC flat: rotation angle φ Power magnet is probed directly Block commutation power stage EC motor controller + (MOSFET) (magnet, winding, sensor) phase 1 HS2 commutation logics phase 3 HS3 HS1 _ phase 2 rotor position feedback Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  31. 31. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Multipole EC motor: commutation 15° Sensorless block commutation rotor position detection without (Hall) sensors measuring the back EMF star point R R zero crossing of back EMF EMF time delay 30° R difficult at low speeds EMF flyback pulse 0° 60° 120° 180° 240° 300° 360° special starting procedure sensorless commutation similar to stepper motor only for continuous operation at high speeds Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  32. 32. 2. DC and BLDC Motors with Permanent Magnetsmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Sensorless block commutation virtual star point virtual star point in the electronics star or delta configuration controller for sensorless operation EMF ~1 kΩ R R ~1kΩ R R R kΩ R ~1 Y ∆ Sinusoidal commutation winding current rotor position must be known very accurately typical 2000 points per rev. 500 pulse encoder (Hall sensors for start: absolute rotor position) resolver as an alternative 0° 60° 120° 180° 240° 300° 360° rotation angle φ phase currents sinusoidal 120° phase shift Sinusoidal commutation for similar to synchronous motor with smooth running even at the variable frequency lowest speeds Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  33. 33. 3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Motor data and operating ranges of DC motors Motor behaviour: speed-torque line, current Motor data and operating ranges Seminar at Electromate © 2010, maxon motor ag, Sachseln, Switzerland DC motor as an energy converter electrical in mechanical energy – speed constant – torque constant PJ = R ⋅ I2 – speed-torque line Pel = U ⋅ I π Pmech = n ⋅M 30 applies to DC and EC motors – "EC" = "brushless DC" (BLDC) Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  34. 34. 3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Characteristic motor data describe the motor design and general behaviour independent of actual voltage or current strongly winding dependent values (electromechanical) – terminal resistance (phase to phase) R – terminal inductance (phase to phase) L – torque constant kM – speed constant kn almost independent of winding (mechanical) – speed-torque gradient ∆n/∆M – mechanical time constant τm – rotor mass inertia JMot Winding resistance resistance increases from left to right low resistance winding high resistance winding thick wire, few turns thin wire, many turns low rated voltage high rated voltage high rated and low rated and starting starting currents currents high specific speed low specific speed (min-1/V) (min-1/V) low specific torque high specific torque (mNm/A) (mNm/A) Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  35. 35. 3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Torque and current: torque constant current direction towards brush forces: force on current leading force conductor in a magnetic field torque: sum of all forces at the distance to the rotating axis influencing parameters: geometry field density design winding number magnetic force field M = kM ⋅ I current direction towards flange current I application Speed constant kn Speed n and induced voltage Uind – law of induction: changing flux in a conductor loop – induced voltage proportional to speed n = k n ⋅ Uind – basically the inverse of kM, but in different units Speed constant kn n0 = k n ⋅ U – mostly used for calculating no-load speeds n0 – unit: min-1 / V Generator constant ke – inverse of kn: motor as a generator (e.g. DC-Tacho). How much voltage is produced per rpm? – units: mV / min-1 V / 1000 min-1 Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  36. 36. 3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Motor as an electrical circuit U I applied motor voltage U: _ + U = L ⋅ ∂I + R ⋅ I + EMF ≅ R ⋅ I + Uind ∂t EMF R L Uind = U − R ⋅ I n M EMF: induced voltage Uind = U−R⋅ kn kM (winding) resistance R winding inductance L ⎛ 30000 R ⎞ n = kn ⋅ U − ⎜ ⋅ ⎟ ⋅M • voltage losses over L can be ⎜ π kM ⎟ 2 neglected in DC motors ⎝ ⎠ ∆n n = kn ⋅ U − ⋅M ∆M Speed-torque line speed n ∆n n = kn ⋅ U − ⋅M ∆M n0 U > UN n0 = k n ⋅ U ∆n U = UN ∆M MH torque M IA current I Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy
  37. 37. 3. Motor Data and Operating Rangesmaxon Seminar at Electromate, March 2010 © by maxon motor ag, 2010 Speed-torque gradient by how much is the speed reduced ∆n, if the output motor torque is enhanced by ∆M? ∆n 30000 n = ⋅R = i speed n ∆M π ⋅ kM 2 MiH M1, n1 strong motor: • flat speed-torque line, small ∆n/∆M n0 ∆n M2, n2 • not sensitive to load changes • e.g. strong magnet, bigger motor ∆M weak motor: • steep speed-torque line, high ∆n/∆M • sensitive to load changes • e.g. weak magnet, smaller motor MH torque M Winding series numerous winding variants adjust n electrical input power (voltage, at U constant current of power supply) mechanical output power thick wire (speed, torque) thin wire M speed-torque gradient basically constant for the winding series constant filling factor: a constant amount of copper fills the air gap Sold & Serviced By: ELECTROMATE Toll Free Phone (877) SERVO98 Toll Free Fax (877) SERV099 www.electromate.com sales@electromate.com DC motor sizing made easy

×