Shock-absorbing sprocket, drive assembly, and the like

Claim 2

In combination with a motorcycle, a motorcycle primary and/or secondary power transmission drive, including a driver sprocket, a driven sprocket, and a positive drive synchronous power transmission belt linking the sprockets in driving relationship and having teeth of desired pitch spaced along the inward driving surfaces of the belt meshing with mating teeth of the sprockets, wherein at least one of the sprockets is a torsionally shock-absorbing power transmission assembly having a hub with at least one radially protruding lug, a rim with circumferentially disposed teeth and at least one inwardly extending ear adapted to mate with the lug of the hub, outer flange bearings attached to and sandwiching the hub on either side thereof, ring surfaces attached to the rim and disposed axially on either side of the sprocket teeth respectively forming radial bearing surfaces with each of the flange bearings, and elastomeric cushion means interposed between the lug and ear to transmit torque therebetween, the cushion means being so configured relative to the shock-absorbing power transmission assembly to define a void volume of at least about 20 percent of the captive sprocket assembly volume determined by the hub, and rim surfaces and other portions of the shock-absorbing power transmission assembly, to accommodate in use angular deflections of at least 9 degrees of the hub relative to the rim.

Claim 3

The combination of claim 1 wherein said void volume is at least 20 percent and said angular deflections are at least 14 degrees at 200 ft.-lbs. torque.

Claim 4

A motorcycle primary or secondary power transmission comprising a driver sprocket, a driven sprocket and a synchronous polyurethane power transmission belt linking the sprockets in driving relationship and having teeth of desired pitch spaced along the inward driving surfaces of the belt meshing with mating teeth of the sprockets, wherein at least one of the sprockets is a torsionally shock-absorbing power transmission assembly having a hub with a plurality of radially protruding lugs, a rim with circumferentially disposed teeth and a plurality of inwardly extending ears adapted to mate with the lugs of the hub, outer flange bearings attached to and sandwiching the hub on either side thereof, ring surfaces attached to the rim and disposed axially on either side of the sprocket teeth respectively forming radial bearing surfaces with each of the flange bearings, and elastomeric cushion means interposed between the lugs and ears to transmit torque therebetween, the cushion means being so configured relative to the shock-absorbing power transmission assembly to define a relatively large void volume with the captive sprocket assembly volume determined by the hub, and rim surfaces and other portions of the shock-absorbing power transmission assembly, to accommodate in use angular deflections of at least 9 degrees of the hub relative to the rim.

Claim 5

A motorcycle primary or secondary power transmission comprising a driver sprocket, a driven sprocket and a synchronous polyurethane power transmission belt linking the sprockets in driving relationship and having teeth of desired pitch spaced along the inward driving surfaces of the belt meshing with mating teeth of the sprockets, wherein at least one of the sprockets is a torsionally shock-absorbing power transmission assembly having a hub with a plurality of radially protruding lugs, a rim with circumferentially disposed teeth and a plurality of inwardly extending ears adapted to mate with the lugs of the hub, outer flange bearings attached to and sandwiching the hub on either side thereof, ring surfaces attached to the rim and disposed axially on either side of the sprocket teeth respectively forming radial bearing surfaces with each of the flange bearings, and elastomeric cushion means interposed between the lugs and ears to transmit torque therebetween, the cushion means being so configured relative to the shock-absorbing power transmission assembly to define a relatively large void volume with the captive sprocket assembly volume determined by the hub, and rim surfaces and other portions of the shock-absorbing power transmission assembly, to accommodate in use angular deflections of at least 9 degrees of the hub relative to the rim.

Claim 6

The drive of claim 3 wherein the belt comprises: a body portion comprising a liquid cast elastomer material; a tensile section embedded within the body portion and extending longitudinally with respect to the intended direction of travel of the belt; said spaced belt teeth being disposed along the inner periphery of the body portion and containing said elastomeric material therein; and a band of wear-resistant fabric comprised of fibers positioned along the outer surface of the teeth, the fibers on the outermost, sprocket-engaging surface of the fabric band being substantially free from total encapsulation of said elastomeric material.

Claim 7

The drive of claim 3 herein the belt comprises: an elastomeric body portion, a tensile band embedded in the body, said belt teeth being integral with the body and containing an elastomeric material which is of the same or different material as said elastomeric body portion and which possesses a determined coefficient of friction, the belt teeth being positioned along the inner periphery sprocket-engaging surface of the belt and having a fibrous cover formed over the teeth and land portions between the teeth, the improvement comprising: said fibrous cover having its outer sprocket-engaging surface substantially free of said elastomeric material of the teeth, said free outer surface of the fibrous cover exhibiting a coefficient of friction which is substantially less than the determined coefficient of friction of the elastomeric material of the teeth.

Claim 8

A torsional vibration absorbing power transmission drive adapted to smooth and dampen torque pulses generated by an engine operable at low engine speeds, to which the vibration absorbing drive is connected, comprising a rotary driver member, a rotary driven member, an endless power transmission member trained about the rotary members in driving relationship, at least one of the rotary members being shock-absorbing and having a hub member having at least two lugs, an outer rim member having at least two radially inwardly extending ears adapted to matingly engage the lugs through torque-transmitting resilient elastomeric cushions interposed therebetween, characterized in that the shock-absorbing rotary member has outer flange bearings attached to and sandwiching the hub on either side thereof, and ring surfaces attached to the rim and disposed axially on either side thereof respectively forming radial bearing surfaces with each of the flange bearings, and the cushions occupy a portion of captive volumes defined within the shock-absorbing rotary member (under no load), the portion of the captive volume unoccupied by a cushion material defining void volume which is at least about 20 percent of the total captive volume, whereby upon rotation of the hub relative to the rim member, in addition to the inherent hysteresis of the elastomeric cushion members the damping properties of the vibration absorbing device are enhanced by frictional forces generated as the cushions are deflected into the unoccupied volume of the captive volumes and slide along wall portions of such captive volumes.

Claim 9

A torsional vibration absorbing power transmission drive adapted to smooth and dampen torque pulses generated by an engine operable at low engine speeds, to which the vibration absorbing drive is connected, comprising a rotary driver member, a rotary driven member, an endless power transmission member trained about the rotary members in driving relationship, at least one of the rotary members being shock-absorbing and having a hub member having at least two lugs, an outer rim member having at least two radially inwardly extending ears adapted to matingly engage the lugs through torque-transmitting resilient elastomeric cushions interposed therebetween, characterized in that the shock-absorbing rotary member has outer flange bearings attached to and sandwiching the hub on either side thereof, and ring surfaces attached to the rim and disposed axially on either side thereof respectively forming radial bearing surfaces with each of the flange bearings, and the cushions occupy a portion of captive volumes defined within the shock-absorbing rotary member (under no load), the portion of the captive volume unoccupied by a cushion material defining void volume which is at least about 20 percent of the total captive volume, whereby upon rotation of the hub relative to the rim member, in addition to the inherent hysteresis of the elastomeric cushion members the damping properties of the vibration absorbing device are enhanced by frictional forces generated as the cushions are deflected into the unoccupied volume of the captive volumes and slide along wall portions of such captive volumes.

Claim 10

The power transmission drive of claim 6 wherein the endless power transmission member is a power transmission belt.

Claim 11

The power transmission drive of claim 7 wherein the power transmission belt is a synchronous belt.

Claim 12

The vibration absorbing drive of claim 6 wherein the void volume is at least about 30 percent and the angular deflection of the hub relative to the rim is at least about 14 degrees at 200 ft.-lbs. torque.

Claim 13

In a shock-absorbing power transmission sprocket assembly, adapted to be used with a positive drive power transmission belt, the sprocket assembly having a hub with at least one radially protruding lug, the lug including a marginal end thereof, a rim with circumferentially disposed teeth and at least one inwardly extending ear adapted to mate with the lug of the hub, and cushioning means interposed between the lug and ear to transmit torque therebetween, the improvement comprising: a pair of outer flange bearings integral with and having a radial dimension at least coextensive with the marginal end of the protruding lug of the hub member, sandwiching the hub on either side thereof; a pair of ring surfaces integral with the rim and disposed axially on either side thereof, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the assembly; said ring surfaces having radial extensions which serve as flanges to retain the power transmission belt in meshing engagement with the teeth of the sprocket; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use a large angular deflection of the hub relative to the rim.

Claim 14

In a shock-absorbing power transmission sprocket assembly, adapted to be used with a positive drive power transmission belt, the sprocket assembly having a hub with at least one radially protruding lug, the lug including a marginal end thereof, a rim with circumferentially disposed teeth and at least one inwardly extending ear adapted to mate with the lug of the hub, and cushioning means interposed between the lug and ear to transmit torque therebetween, the improvement comprising: a pair of outer flange bearings integral with and having a radial dimension at least coextensive with the marginal end of the protruding lug of the hub member, sandwiching the hub on either side thereof; a pair of ring surfaces integral with the rim and disposed axially on either side thereof, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the assembly; said ring surfaces having radial extensions which serve as flanges to retain the power transmission belt in meshing engagement with the teeth of the sprocket; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use a large angular deflection of the hub relative to the rim.

Claim 15

A power transmission drive comprising a driver sprocket, a driven sprocket, and a positive drive synchronous power transmission belt linking the sprockets in driving relationship and having teeth of desired pitch spaced along the inward driving surfaces of the belt meshing with mating teeth of the sprockets, at least one of the sprockets being a shock-absorbing sprocket assembly having a hub with at least one radially protruding lug, the lug including a marginal end thereof; a rim with at least one inwardly extending ear adapted to mate with the lug of the hub; cushioning means interposed between the lug and ear to transmit torque therebetween; a pair of outer flange bearings integral with and having a radial dimension at least coextensive with the marginal end of the protruding lug of the hub member, sandwiching the hub on either side thereof; a pair of ring surfaces integral with the rim disposed axially on either side thereof, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the assembly, the rim carrying circumferentially disposed teeth positioned between the pair of ring surfaces; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use a large angular deflection of the hub relative to the rim.

Claim 16

A power transmission drive comprising a driver sprocket, a driven sprocket, and a positive drive synchronous power transmission belt linking the sprockets in driving relationship and having teeth of desired pitch spaced along the inward driving surfaces of the belt meshing with mating teeth of the sprockets, at least one of the sprockets being a shock-absorbing sprocket assembly having a hub with at least one radially protruding lug, the lug including a marginal end thereof; a rim with at least one inwardly extending ear adapted to mate with the lug of the hub; cushioning means interposed between the lug and ear to transmit torque therebetween; a pair of outer flange bearings integral with and having a radial dimension at least coextensive with the marginal end of the protruding lug of the hub member, sandwiching the hub on either side thereof; a pair of ring surfaces integral with the rim disposed axially on either side thereof, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the assembly, the rim carrying circumferentially disposed teeth positioned between the pair of ring surfaces; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use a large angular deflection of the hub relative to the rim.

Claim 17

A power transmission drive comprising a driver sprocket, a driven sprocket, a positive drive synchronous power transmission belt linking the sprockets in driving relationship and having teeth of desired pitch spaced along the inward driving surfaces of the belt meshing with mating teeth of the sprockets, at least one of the sprockets being a vibration resistant torsionally elastic sprocket assembly having a hub with at least two lugs protruding radially therefrom; a rim with circumferentially disposed teeth and at least two inwardly extending ears adapted to matingly engage the lugs of the hub; resilient cushioning means interposed between the lugs and ears to transmit torque therebetween; outer flange bearings integral with and sandwiching the hub on either side thereof; ring surfaces integral with the rim and disposed axially on either side of the teeth, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the sprocket assembly; said radial bearing surfaces being positioned symmetrically in the axial direction of either side of the teeth; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use an angular deflection of at least 9° of the hub relative to the rim.

Claim 18

A power transmission drive comprising a driver sprocket, a driven sprocket, a positive drive synchronous power transmission belt linking the sprockets in driving relationship and having teeth of desired pitch spaced along the inward driving surfaces of the belt meshing with mating teeth of the sprockets, at least one of the sprockets being a vibration resistant torsionally elastic sprocket assembly having a hub with at least two lugs protruding radially therefrom; a rim with circumferentially disposed teeth and at least two inwardly extending ears adapted to matingly engage the lugs of the hub; resilient cushioning means interposed between the lugs and ears to transmit torque therebetween; outer flange bearings integral with and sandwiching the hub on either side thereof; ring surfaces integral with the rim and disposed axially on either side of the teeth, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the sprocket assembly; said radial bearing surfaces being positioned symmetrically in the axial direction of either side of the teeth; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use an angular deflection of at least 9° of the hub relative to the rim.

Claim 19

A power transmission drive comprising a driver sprocket, a driven sprocket, and an endless chain linking the sprockets in driving relationship, at least one of the sprockets being a shock-absorbing sprocket assembly having a hub with at least one radially protruding lug, the lug including a marginal end thereof; a rim with at least one inwardly extending ear adapted to mate with the lug of the hub; cushioning means interposed between the lug and ear to transmit torque therebetween; a pair of outer flange bearings integral with and having a radial dimension at least coextensive with the marginal end of the protruding lug of the hub member, sandwiching the hub on either side thereof; a pair of ring surfaces integral with the rim disposed axially on either side thereof, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the assembly, the rim carrying circumferentially disposed teeth meshing with the chain and positioned between the pair of ring surfaces; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use a large angular deflection of the hub relative to the rim.

Claim 20

A power transmission drive comprising a driver sprocket, a driven sprocket, and an endless chain linking the sprockets in driving relationship, at least one of the sprockets being a shock-absorbing sprocket assembly having a hub with at least one radially protruding lug, the lug including a marginal end thereof; a rim with at least one inwardly extending ear adapted to mate with the lug of the hub; cushioning means interposed between the lug and ear to transmit torque therebetween; a pair of outer flange bearings integral with and having a radial dimension at least coextensive with the marginal end of the protruding lug of the hub member, sandwiching the hub on either side thereof; a pair of ring surfaces integral with the rim disposed axially on either side thereof, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the assembly, the rim carrying circumferentially disposed teeth meshing with the chain and positioned between the pair of ring surfaces; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use a large angular deflection of the hub relative to the rim.

Claim 21

A power transmission drive comprising a driver sprocket, a driven sprocket, and an endless chain linking the sprockets in driving relationship, at least one of the sprockets being a vibration resistant torsionally elastic sprocket assembly having a hub with at least two lugs protruding radially therefrom; a rim with circumferentially disposed teeth meshing with the chain and at least two inwardly extending ears adapted to matingly engage the lugs of the hub; resilient cushioning means interposed between the lugs and ears to transmit torque therebetween; outer flange bearings integral with and sandwiching the hub on either side thereof; ring surfaces integral with the rim and disposed axially on either side of the teeth, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the sprocket assembly; said radial bearing surfaces being positioned symmetrically in the axial direction of either side of the teeth; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use an angular deflection of at least 9° of the hub relative to the rim.

Claim 22

A power transmission drive comprising a driver sprocket, a driven sprocket, and an endless chain linking the sprockets in driving relationship, at least one of the sprockets being a vibration resistant torsionally elastic sprocket assembly having a hub with at least two lugs protruding radially therefrom; a rim with circumferentially disposed teeth meshing with the chain and at least two inwardly extending ears adapted to matingly engage the lugs of the hub; resilient cushioning means interposed between the lugs and ears to transmit torque therebetween; outer flange bearings integral with and sandwiching the hub on either side thereof; ring surfaces integral with the rim and disposed axially on either side of the teeth, respectively forming radial bearing surfaces with each of the flange bearings to accommodate limited, smoothed and dampened rotative motion between the hub and rim portions of the sprocket assembly; said radial bearing surfaces being positioned symmetrically in the axial direction of either side of the teeth; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hub to define a void volume of at least about 20 percent of the total captive volume defined between the hub, flange bearings and rim surfaces under no load condition, to accommodate in use an angular deflection of at least 9° of the hub relative to the rim.

Claim 23

A power transmission drive comprising a rotary driver member, a rotary driven member, an endless power transmission member linking the rotary members in driving relationship, at least one of the rotary members being a shock-absorbing power transmission assembly having a hub with at least one radially protruding lug; a rim with at least one inwardly extending ear adapted to mate with the lug of the hub; cushioning means interposed between the lug and ear to transmit torque therebetween; a pair of outer flange bearings integral with and sandwiching the hub on either side thereof; a pair of ring surfaces integral with the rim and disposed axially on either side thereof, respectively forming radial bearing surfaces with each of the flange bearings; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hug to define a relatively large void volume under no load condition, to accommodate in use a relatively large angular deflection of the hub relative to the rim.

Claim 24

A power transmission drive comprising a rotary driver member, a rotary driven member, an endless power transmission member linking the rotary members in driving relationship, at least one of the rotary members being a shock-absorbing power transmission assembly having a hub with at least one radially protruding lug; a rim with at least one inwardly extending ear adapted to mate with the lug of the hub; cushioning means interposed between the lug and ear to transmit torque therebetween; a pair of outer flange bearings integral with and sandwiching the hub on either side thereof; a pair of ring surfaces integral with the rim and disposed axially on either side thereof, respectively forming radial bearing surfaces with each of the flange bearings; and said cushioning means comprising elastomeric bodies so configured relative to the adjoining rim, flange bearings and hug to define a relatively large void volume under no load condition, to accommodate in use a relatively large angular deflection of the hub relative to the rim.

Claim 25

The power transmission drive of claim 15 wherein the endless power transmission member is a power transmission belt.

Claim 26

The power transmission drive of claim 16 wherein the power transmission belt is a synchronous power transmission belt.

Claim 27

The power transmission drive of claim 16 wherein the ring surfaces have radial extensions which serve as flanges to retain the power transmission belt during operation of the drive.

Claim 28

The power transmission drive of claim 15 wherein said void volume is at least 20 percent and wherein the angular deflection of the hub relative to the rim is at least 14° at 200 ft.-lbs. torque.

Claim 29

The power transmission drive of claim 15 wherein the radial bearing surfaces are positioned symmetrically in the axial direction on either side of the teeth, whereby in operation of the assembly the bearing load is symmetrically distributed with respect to the endless power transmission member, such as a chain or belt engaging the teeth of the assembly.

Claim 30

The power transmission drive of claim 15 wherein the flange bearings are in the form of disks having an outer diameter greater than the outside diameter of the hub together with the lugs protruding thereform.