**TM 9-8000**

Figure 28-5. Rzeppa Constant Velocity Joint

joint housing that positions the balls. The manner in

the pencil was limited to rolling in a direction

which this action is accomplished can be illustrated by

perpendicular to the long axis of the pencil, whereas the

placing a ruler across a round pencil on a table; if the

balls may move in any direction. When both shafts of

ruler is moved to cause the pencil to roll without slipping,

the constant-velocity joint are in line, that Is, at an angle

the pencil travel is exactly half that of the ruler. In this

of 180 degrees, the balls lie in a plane that is at 90

example there are three objects: the table top, the pencil,

degrees to the shafts. If it is assumed that the driving

and the ruler; two of which are movable members, and

shaft remains in the original position, any movement of

the third stationary. The inner race can be considered as

the driven shaft out of this line will cause the balls to

the stationary table top, the ball as the pencil, and the

move one-half the angular distance. Therefore, if the

driven race as the ruler. The same relative motion

driven shaft moves through an angle of 20 degrees, the

between the pencil and the ruler occurs between the

angle between the shafts will be reduced to 160 degrees,

outer (driven) race and the balls in the constant-velocity

the balls will move 10 degrees in the same direction, and

joint because the balls fit tight enough in the coupling to

the angle between the driving shaft

prevent slippage. The only difference is that motion of

TA233773

**28-6**