Transfer of energy is accomplished through three basic means: The gear, the belt, and the chain.

Statics deals with forces and their effect on a body at rest. Dynamics is the study of force as it works on a rigid body in motion.

Figure 1. TRANSFER OF ENERGY FROM THE MOTOR TO THE END EFFECTOR

Work Of the Manipulator

• Work performed by a manipulator is defined as the movement of an object through distance.

• W = D x F

• D= Distance object moved

• F = force exerted

• Power = D x F / T

• T = time in seconds

Figure 2. ELECTRIC MOTOR AND A WEIGHT

Energy & Torque

• Energy is the capacity to do work.

• PE = W x H

• W = weight of the part

• H = Height to the ground

• KE = ½ M V2

• V = (2gD) 0.5 g = 32 ft/s2

• Torque is the turning effort that is required to rotate a mass through a radius.

• T = F x D

GEARS

• Gearing is the transmission of energy or power through the meshing or contact of the teeth of the gear.

Figure 3. SPUR GEAR DIMENSIONS

Gear • Drive Gear = Pinion

• Driven Gear = Output Gear

• Circumferences is called pitch circles

• Pitch diameter, pitch radius

• Center distance

Figure 4. SPUR GEAR TERMINOLOGY

Gear Ratio Even Number of Gears

Rotation dir. of output gear is opposite to input gear rotation dir.

Odd No. of Gears

Rotation dir. of output gear is the same as the input gear rotation dir.

ND = No. of teeth on a driven gear

NA = No. of teeth on a driver gear

Gear Ratio or GR = ND / NA

GEAR TRAINS

• Planetary Gear

• Stationary Gear = Sun Gear

• Rotational Gear = Planet Gear

• In the simple gear train, each gear has its own shaft.

• In the compound gear train, several gears can be connected to one gear shaft.

V-BELT

• Because of the physical location of components in many robots the energy transfer is through belts.

• The belt used in our robots is Synchronous Belt. Has evenly spaced teeth on the contact surface. More expensive than V-Belt but provides more positive contact with the pulley. It is also called “Timing Belt” and it should be used where direction of rotation constantly changes.

ADJUSTING BELT TENSION