JP3080585U - Chainless bicycle transmission - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an improved chainless transmission device which can be easily installed on a bicycle frame. A chainless transmission for a bicycle includes a front casing (10), a rear casing (13), a crank axle (15), and a transmission assembly. The transmission assembly has a transmission shaft (16), a drive gear, a front gear (17), a rear gear (18), and a driven gear (19). Pipes (14) in front and rear casing to receive transmission shaft
Is connected. Two ears (102) extend from the front casing. Bicycle bottom bracket (3
A connector (11) is fixed to each ear for connection to 2). The transmission can be mounted directly on the bicycle frame. Facilitates installation of the transmission device on the frame. Further, the transmission shaft is capable of slight movement and rotation with respect to the rear gear. This prevents the transmission from bending when riding a bicycle. Improved transmission efficiency and useful life of chainless transmission

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a transmission device, particularly a chainless transmission device for a bicycle.

[0002]

[Prior art]

 Referring to FIG. 6, the conventional bicycle chainless transmission device includes a front casing 50, a rear casing 52, a crank axle 51, and a transmission shaft 54. The front casing 50 is fixed to the bottom bracket 62 of the bicycle frame 60. The crank axle 51 is rotatably received in the front casing 50. Each end of the crank axle 51 extends from a front casing 50 to which a pedal (not shown) is attached. A drive gear 55 is mounted on the crank axle 51 so as to rotate with the crank axle 51. A driven gear 58 is mounted on a rear axle 66 in a hub 64 of a rear wheel (not shown) and is received in the rear casing 52. The hub 64 is held between the rear casing 52 and a chain stay 68 connected to the bottom bracket 62. The rear wheel of the bicycle is mounted on a hub 64. A pipe 53 is connected between the front casing 50 and the rear casing 52 so as to receive the transmission shaft 54. The front gear 56 is attached to one end of the transmission shaft 54 so as to mesh with the drive gear 55. The rear gear 57 is attached to the other end of the transmission shaft 54 so as to mesh with the drive gear 58.

Accordingly, when the rider pedals the pedal connected to the crank axle 51, the crank axle 51 rotates with respect to the front casing 50. The hub 64 and the rear wheels rotate as a result of the transmission of rotational energy via the drive gear 55, front gear 56, transmission shaft 54, rear gear 57 and driven gear 58. The transmission can replace the traditional chain transmission of a bicycle.

However, when the rear wheel hits an object, the rear wheel having the hub 64 moves upward and vibrates. Since the rear gear 57 is fixed to the transmission shaft 54 and meshes with the driven gear 58, the rear gear 57 moves upward together with the hub 64 and vibrates. As a result, the transmission shaft 54 is bent to rotate the transmission shaft along the bent axis. When the transmission shaft 54 rotates, the frictional force increases and the transmission efficiency of the transmission shaft 54 decreases.

The conventional front casing 50 is received in the bottom bracket 62, and the base 502 is formed on the front casing 50 so that the pipe 53 can be connected to the front casing 50. A notch 622 is defined in bottom bracket 62 to engage base 502, and base 502 is exposed from notch 622 for connection with tube 53. However, the manufacturing process of the bicycle frame is complicated because the bottom bracket 62 needs to be machined to fit with the front casing 50. Furthermore, it is very difficult to place the transmission in the bicycle frame 60 when the actual position of the notch 622 is not at the desired position due to errors in the forming process.

[0006] To overcome this shortcoming, the present invention provides an improved chainless transmission that reduces or eliminates such problems.

[0007]

[Problems to be solved by the invention]

 SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved chainless transmission that is easily installed on a bicycle frame. Another object of the present invention is to provide a chainless transmission including other improvements.

[0008]

[Means for Solving the Problems, Functions and Effects of the Invention]

 The transmission includes a front casing, a rear casing, a crank axle, and a transmission assembly. The transmission assembly includes a transmission shaft, a drive gear, a front gear, a rear gear, and a driven gear. A tube is connected to the front casing and the rear casing to receive the transmission shaft. Two ears extend from the front casing. Connectors are secured to each ear for connection to the bicycle's bottom bracket. As a result, the bottom bracket does not require machining. The transmission device can be installed directly on a normal bicycle frame. It has become easy to install the transmission device on the frame.

[0009] The transmission shaft is slightly movable and rotatable with respect to the rear gear to prevent bending of the transmission shaft. The transmission efficiency and service life of the chainless transmission are improved.

[0010] Other objects, advantages and new features of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.

[0011]

[Embodiment of the invention]

 Referring to FIG. 1, the transmission device for a chainless bicycle according to the present invention includes a front casing 10, a rear casing 13, a crank axle 15, and a transmission assembly. The front casing 10 is connected to a bottom bracket 32 of the bicycle. Referring to FIGS. 1 to 3, two ears 102 extend from the front casing 10. The connector 11 has an annular protrusion 112 and is attached to each ear 102. The protrusion 112 of each connector 11 is fitted to one end of the bottom bracket 32. A plurality of bolts 12 extend through both ears 102, both protrusions 112 of connector 11, and bottom bracket 32. A nut 122 is screwed onto each bolt 12 so that the front casing 10 is attached to the bottom bracket 32 by the connector 11 and bolts 12. Since the front casing 10 can be mounted directly to the normal bottom bracket without any machining, the installation of the transmission on the frame 30 is facilitated. In addition, because the protrusion 112 of each connector 11 is round and rotatable with respect to the bottom bracket 32, the front casing 10 can be moved with respect to the bottom bracket 32 to adjust the angle and position of the front casing 10 with respect to the bottom bracket 32. It is rotatable. Mounting the transmission device on the bicycle frame 30 is easier and more flexible.

Referring to FIG. 1, a rear casing 13 is connected to a front casing 10 by a pipe 14. The base 104 is formed on the front casing 10 so that the chain stay 38 can be attached to the base 104. A rear wheel axle 36 in the hub 34 of the bicycle is engaged with the chain stay 38 and the rear casing 13. The seat stays are attached to each of the rear casing 13 and the chain stay 38 so that the rear fork assembly of the bicycle includes a tube 14, a rear casing 13, a chain stay 38, and a seat stay (not shown). Installed.

A crank axle 15 is rotatably mounted in the front casing 10. Each end of the crank axle 15 to which a pedal (not shown) is connected extends from the front casing 10 to the outside.

Referring to FIGS. 1, 4 and 5, the transmission assembly comprises a transmission shaft 16, a drive gear (not shown), a driven gear 19, a front gear 17, a rear gear 18, Is provided. The transmission shaft 16 is rotatably received in the tube 14. One end (first end) of the transmission shaft 16 extends into the front casing 10. The other end of the transmission shaft 16 extends into the rear casing 13. The drive gear (not shown) is mounted on the crank axle 15 so as to rotate therewith. The driven gear 19 is mounted on a rear wheel axle 36 of a bicycle hub 34. The driven gear 19 is received in the rear housing 13. The front gear 17 is mounted on one end of the transmission shaft 16 and is received in the front casing 10. The front gear 17 meshes with the drive gear. A tooth 162 is formed at an end of the transmission shaft 16 having the front gear 17. A columnar stub 172 extends from one side of the front gear 17. Internal teeth 174 that mesh with the teeth 162 of the transmission shaft 16 are defined in the stub 172, and the transmission shaft 16 rotates together with the front gear 17 by the engagement of the teeth 162 and the internal teeth 174. In practice, the end of the transmission shaft 16 having the teeth 162 extends through the front gear 17. A hole provided with a thread groove (screw hole) (not shown) is defined at the end of the transmission shaft 16 having the teeth 162. A bolt 21 extending through a washer 22 is screwed into the screw hole of the transmission shaft 16. As a result, the front gear 17 is fixed to the transmission shaft 16. In addition, a bearing 20 is received in the front casing 10 and presses against the peripheral surface of the stub 172 of the front gear 17. The bearing 20 is tightened between the front gear 17 and one end of the pipe 14. The rotation of the front gear 17 is made smoother.

The rear gear 18 is attached to the other end (second end) of the transmission shaft 16 and is received in the rear casing 13. The rear gear 18 meshes with the driven gear 19. A neck 164 having a diameter smaller than the diameter of the transmission shaft 16 is formed on the transmission shaft 16. A ball 166 having a diameter greater than the diameter of neck 164 is formed at the free end of neck 164. The through hole 168 is defined to extend radially through the ball 166. A stub 182 extends from one side of the rear gear 18. A central hole 184 having a diameter greater than the diameter of the neck 164 of the transmission shaft 16 is defined in the stub 182 of the rear gear 18. Neck 164 and ball 166 are received in central hole 184 of stub 182 such that a gap or gap is defined between the inner surface of central hole 184 and neck 164. A through hole 186 is formed in stub 182 and is aligned with through hole 168 of ball 166. Pin 24 extends through stub 182 and through holes 186, 168 in ball 166 to pivotally connect ball 166 to stub 182. In addition, a bearing 25 is received in the rear casing 13 and presses against the peripheral surface of the stub 182 of the rear gear 18. An annular groove 188 is defined on the outer peripheral surface of the stub 182. A fastener 26 is fixed in the groove 188 so as to be in contact with the bearing 25. As a result, the rotation of the rear gear 18 becomes smooth.

Referring to FIGS. 1, 4 and 5, when a bicycle rider steps on the pedal mounted on the crank axle 15, the crank axle 15 rotates. The transmission of rotational energy through the transmission assembly including the driving gear, the front gear 17, the transmission shaft 16, the rear gear 18, and the driven gear 19 causes the rear wheel axle 36 to rotate. Bicycles with a chainless transmission go forward.

In addition, because there is the gap between the neck 164 of the transmission shaft 16 and the stub 182 of the rear gear 18 and the ball 166 is pivotally mounted on the stub 182, the rear gear 18 Rotate in a certain range. This makes it possible to prevent the transmission shaft 16 from bending when the rear wheel hits the object. The rotation axis of the transmission shaft 16 is always kept straight. As a result, the transmission efficiency of the transmission shaft 16 is improved, and the useful life of the transmission device is extended.

While many features and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the present invention, the disclosure is of embodiments and the broad scope of the terms set forth in the utility model registration claims Detailed changes may be made in matters of shape, size and arrangement of each part within the principles of the present invention, throughout the content indicated by the general meaning.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a chainless transmission device according to the present invention.

2 is a partial side view of the transmission of FIG. 1 showing the attachment of the front casing to the bottom bracket of the bicycle.

FIG. 3 is a plan view including a partial cross section of the transmission device of FIG. 2 showing a front casing, a bottom bracket and mounting.

FIG. 4 is an exploded perspective view of a transmission shaft, a front gear, and a rear gear of FIG. 1;

5 is a cross-sectional side view of the transmission assembly of FIG.

FIG. 6 is an exploded perspective view of a conventional chainless transmission device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Front casing 11 Connector 12 Bolt 13 Rear casing 14 Pipe 15 Crank axle 16 Transmission shaft 17 Front gear 18 Rear gear 19 Driven gear 30 Frame 32 Bottom bracket 34 Hub 102 Ear part 112 Annular projection 122 Nut

Claims (3)

[Utility model registration claims] 1. A transmission device for a bicycle comprising a frame, a bottom bracket provided on the frame, and a hub having a rear wheel axle, comprising: a front casing;
A crank axle rotatably mounted on the front casing, the crank axle adapted to be connected to a pedal and extending from the front casing; a drive gear rotatably mounted on the crank axle; and the front casing A pipe having one end fixed to the pipe, a rear casing fixed to the other end of the pipe, and a first end extending into the front casing, the transmission shaft being rotatably received in the pipe. A transmission shaft having a second end extending into the rear casing; and a front shaft rotatably mounted on the first end of the transmission shaft and received in the front casing to mesh with the drive gear. A gear and a gear rotatably mounted on the second end of the transmission shaft and received in the rear casing. A gear, and a driven gear rotatably received in the rear casing and adapted to be mounted on the hub, the driven gear meshing with the rear gear, and two ears are provided on the front gear. Extending from the casing, a connector is secured to each ear, the connector having an annular projection adapted to be interference-fitted to one end of the bottom bracket, and a plurality of bolts are provided on the ear and the ear. A transmission device extending through a connector, wherein a nut is threadedly engaged with each bolt to attach the front casing to the bottom bracket with the connector. 2. A stub having teeth formed at a first end of the transmission shaft, a stub extending from one end of the front gear and having internal teeth meshing with teeth of the transmission shaft, and the front casing. A bearing received in the bearing mounted on a stub of the front gear;
A first end of the transmission shaft extending through the front gear, the first end having a threaded hole defined in the first end, and a bolt extending through a washer; 2. The bolt of claim 1, wherein said front gear includes a bolt that is freely rotatable with respect to said front casing, said screw being screwed into a threaded hole in said transmission shaft to secure the same to a first end of said transmission shaft. Transmission device. 3. A transmission shaft formed at a second end of the transmission shaft.
A neck having a diameter smaller than the diameter of the transmission shaft; a ball formed at a free end of the neck having a diameter larger than the diameter of the neck; a through hole defined radially through the ball; A stub extending from one end of the rear gear for connection with a transmission shaft, and a central hole having a diameter greater than the diameter of the neck of the transmission shaft, the stub of the rear gear being adapted to receive the ball and the neck. A central hole defined in the stub, a gap defined between the inner surface of the central hole and the neck, a through hole defined in the stub and aligned with a through hole of the ball, A pin extending through the through hole of the stub and the through hole of the ball so as to pivotally attach to the stub; and a pin received in the rear casing and attached to the stub of the rear gear. A chain stay, a groove defined around the outer periphery of the stub, a fastener held in the groove for securely holding the bearing, and a base formed on the front casing. And a base adapted to be mounted thereon, whereby the rear gear is pivotally connected to the second end of the transmission shaft and the rear gear is free to rotate with respect to the rear casing. The transmission device according to claim 1, wherein the transmission device is possible.