Lubrication improvement for variable speed drives

An automatic grease feeding system to provide for lubrication to variable pitch pulleys is disclosed having a stationary grease feeder providing pressurized grease lubrication through a stationary to rotating interface with the shaft carrying variable pitch pulley.

BACKGROUND OF THE INVENTION 
Prior art variable pitch pulley drive systems have suffered from an 
inability to provide for reliable lubrication of the variable pulley 
mechanism. More particularly, experience has proven that users of such 
systems neglect to lubricate such systems when needed, and furthermore are 
sometimes unable to properly lubricate the system since proper lubrication 
of such prior art systems required the user to adjust the pulley pitch 
while lubricating in order to coat all axial load bearing surfaces between 
the pulley and its respective shaft. The nature of some applications of 
such variable pitch pulley drives prohibited adjustment during 
lubrication. 
One approach to solving this problem which is followed by a number of 
manufacturers has been to provide a non-metallic keyed sleeve between the 
axially movable pulley half and the shaft which carries it. This has 
resulted in some degree of success, however, rapid wearout and limited 
peak torque capacity have continued to be problems with this approach. 
BRIEF SUMMARY OF THE INVENTION 
The present invention overcomes the shortcomings of the prior art by 
providing an improved lubrication system for a variable pitch pulley drive 
system having a pressurized grease feeder delivering lubricating grease to 
the pulley through a rotating seal-shaft interface.

DETAILED DESCRIPTION 
FIG. 1 shows a section view of a part of a variable speed drive 10 which 
has a variable pitch pulley 11 mounted on a shaft 12 by means of a bearing 
14 journaled in an end wall 16 of an enclosure for drive 10. The pitch of 
pulley 11 is varied by means (not shown) to move pulley half 44 from the 
position shown by a solid line to the position shown by the dot-dash line. 
This changes the pitch diameter of belt 13, varying the drive speed. A 
support 18 is secured to end wall 16 by suitable means such as rivets or 
screws 20. Support 18 encloses a stationary hollow pipe or sleeve 22 which 
receives a pressurized automatic grease feeder 24 at threaded engagement 
26. Grease feeder 24 has a hollow chamber 28 which may be fitted with 
grease by means of a conventional grease gun fitting 30. As grease is 
supplied through fitting 30 to chamber 28, a piston 32 is driven against 
coil spring 34 to the position shown. 
A seal cup 36 (preferably formed as a stamping) is received in threaded 
engagement with shaft 12 by threads 28. Cup 36 rotates with shaft 12 and 
carries a rotating lip seal 40 which rides against non-rotating sleeve or 
cylinder 22. Shaft 12 has a hollow passageway 42 extending from the end of 
the shaft in engagement with cup 36 to an axially movable sheave half 44. 
Sheave half 46 is fixed to shaft 12 while sheave half 44 is free to move 
axially, being carried by splines 41 on shaft 12. Radially directed 
apertures 43 connect passageway 42 with the spline interconnection between 
sheave half 44 and shaft 12. 
In operation, with cavity or chamber 28 filled with grease, piston 32 
forces grease through passageway 47 in feeder 24. The grease passes 
through hollow sleeve 22, seal cup 36, and passageway 42 and ultimately 
lubricates the mating splines on sheave half 44 and shaft 12. Seal 40 
prevents grease from escaping at the rotating interface. 
FIG. 2 shows an alternative embodiment where shaft 12 has a hollow 
extension 48 secured to it. Extension 48 rotates with shaft 12 and is 
received in stationary seal 50. Seal 50 and grease feeder 24 are mounted 
in a cap 52 which is secured to machine frame 16 by conventional machine 
screws or bolts 54. 
The invention is not to be taken as limited to all of the details thereof 
as modifications and variations thereof may be made without departing from 
the spirit or scope of the invention. Accordingly,