Background and Summary of the Invention
This invention relates generally to clutch/brake units and in particular to a reversing drive mechanism for the output shaft of a clutch/brake unit.
In prior art clutch/brake units, in order to have a reversing drive feature permitting the output shaft to be driven in either direction of rotation, an expensive reversing motor was necessary. The present invention eliminates the need for the expensive reversing motor and allows less expensive single direction of rotation drive motors to be attached to the input shaft while the output shaft is driven in either direction of rotation, with reversible direction of either the input or output shafts. This single direction of rotation further permits the vanes of any oil pumping device driven by any of the shafts of the units to be articulated or curved in one direction to improve the pumping capability of the pump.
The present invention further has the object of a heavy duty capability and quick response to change of direction by pneumatic controls. The present invention also has the further object of the capability of mounting the output shaft right-handed, left-handed or at any angular relationship with regard to the clutch/brake shaft and in any radial direction from that shaft.
Additional objects and advantages can be seen in the following specification and claims and attached drawings.
Brief Description of the Drawings
FIG. 1 is a side sectional view of the clutch/brake unit and reversing drive unit of the present invention.
Detailed Description of the Preferred Embodiments
Referring to FIG. 1, a clutch/brake unit 10 is illustrated similar to that described in applicant's U.S. Pat. No. 3,698,898, issued Oct. 10, 1972. The clutch/brake unit 10 is comprised of a housing 12, axially aligned input shaft 14 and main drive shaft 16 mounted in the housing 12, a non-rotatable pneumatically actuated piston 18 in the housing 12, a series of radially disposed clutch plates 20 mounted for rotation with the input shaft 14, a series of radially disposed brake plates 22 spaced axially from the clutch plates 20 and non-rotatably attached to the housing 12, a series of friction discs 24 mounted on the main drive shaft 16 for rotation therewith and adapted for selective frictional engagement with the clutch 20 and brake 22 plates, a clutch actuating member 26 and a brake actuating member 28 carried on the main drive shaft 16 adjacent the clutch 20 and brake 22 plates, securement bolts 30 extending between the last two members 26 and 28, whereby the members 26 and 28 are movable together axially of the main drive shaft 16, and a bearing 32 disposed between the piston 18 and the brake actuating member 28, through which the piston 18 drives the clutch 26 and brake 28 actuating members. Movement of the piston 18 in one direction serves to simultaneously frictionally engage the clutch plates 20 with certain of the friction discs 24 and to release the remaining friction discs 24 from frictional engagement with the brake plates 22, and movement of the piston 18 in the other direction serves to simultaneously release the clutch plates 20 from the frictional engagement with certain friction discs 24 and to frictionally engage the remaining friction discs 24 with the brake plates 22. Springs 34 are mounted in recesses 36 at one end of the housing 12 to normally urge the piston 18 toward a position wherein the springs 34 effect engagement of the brake 38 and release of the clutch 40. A pumping mechanism 42 is disposed on the input shaft 14 having a centrifugal pump 44 rotatable with the shaft 14 in an annular chamber 46. The pump 44 has vanes 48 at the outer periphery thereof to direct the fluid into an oil cooler 50 and other passageways 52, 54 of the oil delivery system of the clutch/brake unit 10. The vanes 48 may be curved in one direction (usually the direction of rotation) since the pump 44 will rotate in only one direction.
The main drive shaft 16 extends into a second housing 61 for the reversing drive mechanism 62 fixedly secured to the clutch/brake housing 12 by series of circumferentially spaced bolts 64. The housing 61 is comprised of an annular sidewall 66 and an end portion 68 secured to the sidewall by a series of circumferentially spaced bolts 70. The annular housing sidewall 66 includes bearings 72 for the main drive shaft 16. The annular housing sidewall 66 has an aperture 73 therein through which an extended, radially outwardly directed housing portion 74 is inserted in and secured to the housing sidewall 66 by series of circumferentially spaced bolts 76. The annular housing sidewall 66 further comprises bearings 78 at an intermediate location of the output shaft 16 secured to the annular housing sidewall 66 via a piston 80. The driving end 82 of the main drive shaft 16 is secured in bearings 84 fixedly secured by the end portion 70. The main drive shaft 16 has a pair of annular beveled gears 88 and 90 disposed to face one another at spaced apart locations. The gears 88 and 90 are spaced apart far enough so that a beveled pinion gear 92 may engage only one or the other when disposed at right angles thereto. The beveled pinion gear 92 is disposed on the output shaft 94 of the reversing drive unit 62, which output shaft 94 is rotatably secured within the extended housing portion 68 by bearings 96 and 98.
The piston 80 is sealingly engaged with the annular housing sidewall 66 by seals 100, 102, and 104 to provide two annular chambers 106 and 108. Chambers 106 and 108 communicate with ports 110 and 112 respectively. As air is alternatively fed to one of the two ports 110, 112, the piston 80 is forced in one direction or the other. The spaced apart beveled gears 88, 90 on the main drive shaft 16 are secured together by an intermediate portion 114 which is slidably disposed on splines 116 integral with the main drive shaft 16, which intermediate portion 114 is driven by the piston 80. Thus, the direction of rotation is determined by which of the two ports 110 or 112 is fed compressed air to force the intermediate portion 114 (and gears 88 and 90) to the right or to the left (as illustrated) and engage the respective annular gear 88, 90 to rotate the beveled pinion gear 92 and shaft 94 in one direction or the other relative to the single direction that the main drive shaft 16 is rotated.
It can be also clearly seen from the above disclosure that the reversing drive mechanism 62 may be operably associated between a drive motor and an extended input shaft 14 of the clutch/brake unit 10.
While it will be apparent that the preferred embodiment illustrated herein is well calculated to fulfill the object above stated, it will be appreciated that the present invention is susceptible to modification, variation and change without departing from the proper scope or fair meaning of the subjoined claims.