POLYMER SPRING CONTROLLED PULLEY ASSEMBLY FOR ROTARY DEVICES
First Claim
1. A drive system for a rotary device having a shaft, comprising:
- a pulley adapted to be rotated by a prime mover, the pulley having a first plurality of radial projections extending from an inner surface of the pulley;
a hub connected to the shaft and journaled within the pulley, the hub having a second plurality of radial projections extending from an outer surface of the hub, the first and second pluralities of projections being interleaved and forming a plurality of spaces therebetween;
a pair of annular members located on the hub axially on opposite sides of said projections that together with said projections and said spaces define a plurality of cavities; and
a plurality of solid resilient polymer spring members disposed in said cavities, said resilient polymer of said spring members being selected from the group consisting of polyether urethanes, polyester urethanes, and co-polyesters of fully polymerized hard segments of crystalline polybutylene-terephthalate (PBT) and soft segments of amorphous polyesters or polyethers, the spring members having a size relative to the cavities such that the spring members engage the first and second projections and, upon sudden relative angular bidirectional velocity changes between the prime mover and shaft and corresponding relative angular rotation of the pulley and the hub, the projections resiliently deform said spring members within said cavities to dampen the impact of said velocity changes on the shaft until a predetermined maximum relative angular rotation is reached.
1 Assignment
0 Petitions
Accused Products
Abstract
A drive system for a rotary device, such as an automotive alternator compensates for and reduces the effect of sudden bidirectional rotational velocity variations of the pulley caused by sudden acceleration and deceleration of an internal combustion engine without using a one-way clutch. The drive system comprises a pulley comprising a tubular barrel having a plurality of radial projections extending inwardly from its inner surface, and a cylindrical hub that is journaled within the pulley and connected to the alternator shaft. The hub has a plurality of radial projections extending outwardly from its outer circumference which are interleaved between the pulley projections. A plurality of solid resilient polymer spring members are disposed in the cavity spaces between the projections. Upon sudden acceleration or deceleration of the pulley, it rotates angularly relative to the hub and shaft to resiliently compress the polymer spring members, which exert a counter restoring force to eliminate the relative angular rotation.
31 Citations
24 Claims
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1. A drive system for a rotary device having a shaft, comprising:
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a pulley adapted to be rotated by a prime mover, the pulley having a first plurality of radial projections extending from an inner surface of the pulley; a hub connected to the shaft and journaled within the pulley, the hub having a second plurality of radial projections extending from an outer surface of the hub, the first and second pluralities of projections being interleaved and forming a plurality of spaces therebetween; a pair of annular members located on the hub axially on opposite sides of said projections that together with said projections and said spaces define a plurality of cavities; and a plurality of solid resilient polymer spring members disposed in said cavities, said resilient polymer of said spring members being selected from the group consisting of polyether urethanes, polyester urethanes, and co-polyesters of fully polymerized hard segments of crystalline polybutylene-terephthalate (PBT) and soft segments of amorphous polyesters or polyethers, the spring members having a size relative to the cavities such that the spring members engage the first and second projections and, upon sudden relative angular bidirectional velocity changes between the prime mover and shaft and corresponding relative angular rotation of the pulley and the hub, the projections resiliently deform said spring members within said cavities to dampen the impact of said velocity changes on the shaft until a predetermined maximum relative angular rotation is reached. - View Dependent Claims (2, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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3. (canceled)
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16. (canceled)
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17. (canceled)
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18. A drive system for a rotary device having a shaft, comprising:
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a pulley adapted to be connected to a drive belt, the pulley having a first plurality of radial projections extending from an inner surface of the pulley; a hub connected to the shaft and journaled within the pulley, the hub having a second plurality of radial projections extending from an outer surface of the hub, the first and second pluralities of projections being interleaved and forming a plurality of cavities therebetween; a plurality of solid spring members formed of a resilient polymer disposed in said cavities, the resilient polymer being selected from the group consisting of polyether urethanes, polyester urethanes, and co-polyesters of fully polymerized hard segments of crystalline polybutylene-terephthalate (PBT) and soft segments of amorphous polyesters or polyethers, wherein upon sudden relative angular bidirectional rotational deviations between the pulley and the hub, the projections resiliently deform said spring members within said cavities to dampen the impact of said rotational deviations on the shaft. - View Dependent Claims (19, 20, 21, 22, 23, 24)
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Specification