Sprag assembly for one-way clutches

#This invention relates to a sprag assembly for one-way overrunning clutches having an inner and an outer race wherein a sprag cage rotatably retains a series of sprags therein having inner and outer cam race engaging surfaces which are rotated into driving engagement with the races in one direction and are overrunning or disengaging in the other direction of relative operation of the inner and outer races. The sprags are provided with a counterweight portion specifically positioned with respect thereto which will cause the sprags to rotate in the nonengaging direction under the effects of centrifugal force when the cage is rotated in overrunning condition with one of said races against the effects of a sprag engaging and urging means whereby at a predetermined rotational speed, the sprags will become completely disengaged from the races during overrunning above the predetermined speed.

#Presently known types of overrunning clutches generally do not provide for total disengagement of the sprags with respect to a race being overrun thereby, and as a result, a large amount of localized wear takes place on the sprags between a race being overrun and the sprags.

#Under these conditions, the overrun race will probably wear uniformly, however, the sprags will engage the overrun race at a particular point on the sprag causing the sprag to wear nonuniformly. This nonuniform wear disrupts the appropriate operation thereof of the sprags.

#Other advantages and novel aspects of the invention will become apparent upon consideration of the following detailed description, in conjunction with the accompanying drawing wherein:

#FIG. 1 is a sectional view of a one-way overrunning sprag clutch showing the novel sprag assembly of this invention;

#FIG. 2 is a partially broken away sectional view taken along line 2--2 of FIG. 1 showing the details of the sprag assembly;

#A one-way cam or overrunning sprag clutch generally represented by the numeral 10 is disclosed herein (FIG. 1) for the purpose of illustrating the invention, and includes generally, among other things, an inner rotating drive member 11, an outer rotating drive member 12, bearings 13 supporting the outer member 12 on the inner member 11, lubricant seals 14, and the sprag assembly 15 (FIGS. 1-3) of this invention, which provides a drive or an overrunning condition between the inner and outer members 11 and 12. The inner member 11 is provided with an inner race surface 20 adjacent the sprag assembly 15 of this invention and the outer member 12 is similarly provided with an outer race surface 21 adjacent the sprag assembly 15 of this invention.

#The sprag assembly 15 of this invention includes generally two cage rings 22, two energizing springs 23, a series of cage spacers 24, a series of sprags 25, and a yieldable friction-drag or urging means 26 (FIG. 2). The cage rings 22 are provided with circumferentially spaced apertures 27 for receiving sprag trunnions 28 and are coaxially spaced apart an appropriate distance to receive the sprags 25 therebetween by the spacers 24 held in position by screws (FIGS. 1, 2 and 3).

#The sprags 25 are provided with the trunnions 28 thereof rotatably mounted in the apertures 27 of the cage rings 22 and are provided with outer cam surfaces 30 and inner cam surfaces 31 adapted to drivingly engage the outer race 21 and the inner race 20 when the inner race 20 is rotated clockwise with respect to the outer race 21 (FIGS. 2, 4 and 5) and to normally drivingly disengage and drag on the outer race in an overrunning condition when the inner race 20 is moved counterclockwise with respect to the outer race 21.