Actuator Components - University Of Maryland · 2016-10-29 · Actuator Components • Actuators – Hydraulics – Pneumatics – Electric Motors • Gearing • Bearings • Seals

Actuator Components ENAE 788X - Planetary Surface Robotics

U N I V E R S I T Y O FMARYLAND

Actuator Components

• Actuators – Hydraulics – Pneumatics – Electric Motors

• Gearing

• Bearings • Seals

1



Fundamental Elements of Robotics

2

SensingPlanning

and Reasoning

Actuation

Environment



Prime Mover Taxonomy

• Electrical – Direct Current – Alternating Current

• Non-Electrical – Hydraulics – Pneumatics – Chemical – Thermal – Stored Energy

3



Hydraulics and Pneumatics

4



Pneumatic Actuator Cutaway

5



Hydraulic System Schematic

6



Hydraulic Spool Valve Schematic

7



Brushed DC Motor Schematic

8



DC Brushed Motor Schematic

9



Brushed DC Motor Commutator

10



Brushless DC Motor

11



Brushless Outrunner Motor

12



DC Brushless Motor Schematic

13



Basic DC Motor Drive Characteristics

14



Effects of Temperature on DC Motors

15



Effects of Temperature on DC Motors

16



Speed as a Function of Torque

17



Standard DC Motor Characteristics

18



Motor Power

19

P = ⌧!

P = ⌧ (!NL + E⌧) = ⌧!NL + E⌧2

! = E⌧ + !NL (E < 0)

dP

d⌧= !NL + 2E⌧ = 0

⌧max power

= �!NL

2E



DC Motor Power and Efficiency

20



Typical DC Motor Specification

21



Standard Motor Specifications

22



Axial Flux Motor

23



Stepper Motor Exploded Image

24



Stepper Motor Schematic

25



Gearhead Motor Cutaway

26



Gear Forms

27



Gearing Calculations

28

Gear ratio ⌘ N

⌧output

= N⌘gear

⌧input

!output

=!input

N

Ioutput

= N2Iinput

⌧ = I!̇ =) I =⌧

!̇

Ioutput

=⌧output

!̇output

Ioutput

=N⌘

gear

⌧input

!̇input

N

Ioutput

= N2⌘gear

Iinput

!̇output

=!̇input

NFor ideal gearing,



Spur Gears

29



Spur Gear Parameters

30



Helical Gears

31



Planetary Gears

32



Bevel Gears

33



Bevel Gear Kinematics

34



Automotive Differential Schematic

35



Automotive Differential (more realistic)

36



Worm Gear

37



Chain Drives

38



Chain Drive with Idler

39



V-Belt Drive

40



Toothed Belt Drive

41



Rack and Pinion Gears

42



Screw Drive Schematic

43



Linear Actuator Cutaway

44



Cup-Style Harmonic Drive

45



Operating Principle of Harmonic Drives

46



Pancake Harmonic Drive

47

Documents

Actuator Components - University Of Maryland · 2016-10-29 · Actuator Components • Actuators – Hydraulics – Pneumatics – Electric Motors • Gearing • Bearings • Seals