Patent Application
20110221263
The present invention relates to a rotary unit, and more particularly, to a rotary unit cooperated with journal bearings to allow the hub assembly to be operated smoothly.
A conventional bicycle hub generally includes a driving tube connected to one end thereof and an axle extends through the hub and the driving tube. The driving tube includes a ratchet portion and a sprocket portion, and at least one bearing is located between the axle and the hub to le the hub together with the driving tube to rotate in one direction to drive the bicycle.
There are bearings used in the bicycle hub assembly to allow the hub to be rotated relative to the axle. The bearings used for hub assembly generally include two types which are the rolling contact bearings and the journal bearings. The rolling contact bearings mean that the two parts that have relative movement are in the form of rolling. The journal bearings include lubricant which provides a shear stress between the two parts that have relative movement. Most of the journal bearings are self-lubricating bearings.
A bicycle hub assembly known to applicant includes an axle which is connected to the bicycle frame and a hub is mounted to the axle. The hub includes ratchet grooves defined in one end thereof and a driving tube is connected to the ratchet grooves of the hub. The driving tube includes a sprocket portion to which the sprockets are connected. A self-lubricating bearing is located between the driving tube and the axle which extends through the self-lubricating bearing. The self-lubricating bearing includes an insertion which is inserted into the driving tube and a locking member is mounted to the axle and securely positions the driving tube and the self-lubricating bearing.
However, the thickness of the insertion of the self-lubricating bearing and the length of the sleeve have to be precisely manufactured, if the outer edges of the insertion and the sleeve are not located in flush with each other, the self-lubricating bearing will be locked and cannot rotate. The higher precision requirement increases the manufacturing cost of the hub assembly.
Another bicycle hub assembly known to applicant includes a hub mounted to the axle with multiple first bearings located therebetween. A driving tube is connected to one end of the hub by a clutch unit and at least one second bearing is located between the driving tube and the axle. Two restriction units are connected to two ends of the axle so as to restrict the axial movement of the hub relative to the axle. The restriction units include a ratchet ring which is threadedly connected to the hub, a collar located in the ratchet ring and connected to the driving tube, multiple pawls connected to exterior of the collar, and resilient members for keeping the pawls to be engaged with the ratchet ring. The axle includes a support portion extending radially from the axle and the support portion is located corresponding to the collar. A self-lubricating bear is mounted between the support portion and the collar, and includes inner surface which is mounted to the support portion. The self-lubricating bear further includes an outer surface which is engaged with an inner surface of the collar.
The self-lubricating bearing is located between the support portion and the collar, so that one end of the self-lubricating bearing is not well positioned, so that the self-lubricating bearing will loosen in the opened direction to affect the operation of the hub assembly.
The present invention intends to provide a hub assembly wherein the self-lubricating bearings are well positioned on both ends thereof to ensure smooth operation of the hub assembly.
The present invention relates to a hub assembly and comprises a hub and a driving tube is connected to one end of the hub. The driving tube includes a connection end at a first end thereof and a sprocket portion is located on a second end of the driving tube, wherein the connection portion is inserted into the hub. The sprocket portion has a reception hole defined in an end thereof. An axle extends through the hub and the driving tube. A rotary unit is located between the reception hole and the axle, and includes a tubular member which is mounted to the axle and includes a stop flange extends radially from an outer surface thereof. At least one space is defined between the tubular member, the stop flange and an inner periphery of the reception hole. At least one self-lubricating bearing is located in the space.
The primary object of the present invention is to provide a hub assembly and the self-lubricating bearings are well positioned so as to avoid the self-lubricating bearing from movement in axial direction.
Another object of the present invention is to provide a hub assembly wherein the self-lubricating bearings are clamped between the stop flange of the tubular member, the reception hole of the driving tube and the locking unit. The arrangement simplifies the steps of assembly and reduces manufacturing cost.
The present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, a preferred embodiment in accordance with the present invention.
Referring to
The driving tube 20 includes a connection end 21 at a first end thereof and a sprocket portion 22 located on a second end of the driving tube 20. The connection portion 21 is inserted into the hub 10 and the sprocket portion 22 has a reception hole 23 defined in an end thereof. The ratchet unit 50 is mounted to the connection end 21 of the driving tube 20 and co-rotated with the driving tube 20.
The rotary unit 40 is located between the reception hole 23 and the axle 30, and includes a tubular member 41 which is mounted to the axle 30 and includes a stop flange 411 extending radially from an outer surface thereof. Two spaces are defined between the tubular member 41, the stop flange 41 and an inner periphery of the reception hole 23. Two self-lubricating bearings 42, 43 are located in the two spaces respectively. The tubular member 41 includes a positioning shoulder 412 located in an inner periphery thereof and the axle includes a positioning flange 31 extending radially from an outer periphery thereof, the positioning flange 31 contacts the shoulder 412.
The sprocket unit 60 is mounted to the sprocket portion 22 of the driving tube 20 and co-rotated with the driving tube 20. In this embodiment, the sprocket unit 60 includes a single sprocket.
The locking unit 70 includes a locking ring 71, a resilient member 72 and a locking nut 73. The locking ring 71 has one side thereof contacting the sprocket unit 60. The resilient member 72 is a ring-shaped member and clamped between the locking nut 73 and the self-lubricating bearing 43. The locking nut 73 has one end extending through the resilient member 72 and contacting an end surface of the tubular member 41.
The two self-lubricating bearings 42, 43 are well positioned so that the rest of the parts are easily assembled and the rotation of the hub 10 is smooth. The two self-lubricating bearings 42, 43 do not move in axial direction.
When assembling, the axle 30 extends through the hub 10 and the self-lubricating bearing 42, the tubular member 41, the other self-lubricating bearing 43 are connected to the reception hole 23 in sequence. The two self-lubricating bearings 42, 43 are in contact with two sides of the stop flange 411. The ratchet unit 50 is then mounted to the connection end 21 and the positioning flange 31 contacts the shoulder 412. The sprocket unit 60 is then mounted to the sprocket portion 22 and the locking ring 71, the resilient member 72 and the locking nut 73 are mounted to the axle 30 one by one. The locking ring 71 is threadedly connected to the driving tube 20 and the locking nut 73 is threadedly connected to the axle 30. The locking ring 71 contacts the outside of the sprocket unit 60 and the resilient member 72 is clamped between the locking nut 73 and the self-lubricating bearing 43. The locking nut 73 extends through the resilient member 72 and contacts the end surface of the tubular member 41.
The two sides of self-lubricating bearing 42 are in contact with the stop flange 411 and the inner end of the reception hole 23 so that the self-lubricating bearing 42 is well positioned and does not move in axial direction.
The two sides of self-lubricating bearing 43 are in contact with the stop flange 411 and the resilient member 72 so that the self-lubricating bearing 43 is well positioned and does not move in axial direction.
The two self-lubricating bearings 42, 43 are precisely positioned so that other parts are easily assembled. The well positioned two self-lubricating bearings 42, 43 lead a smooth operation of the hub relative to the axle 30.
The positioning of the two self-lubricating bearings 42, 43 simplifies the steps of assembling of the hub assembly and reduces the manufacturing cost.
The cooperation between the positioning flange 31 and the shoulder 412 makes the assembling steps of the hub 10 and the axle 30 easy and convenient. By the arrangement, the driving tube 20 and the rotary unit 40 will not contact the sprocket unit 60 which is rotated with less friction.
While we have shown and described the embodiment in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.
