WO2009043204A1

WO2009043204A1 - Automatic speed variator for bicycle

Info

Publication number: WO2009043204A1
Application number: PCT/CN2007/003075
Authority: WO
Inventors: Hui Cheng
Original assignee: Hui Cheng
Priority date: 2007-09-29
Filing date: 2007-10-29
Publication date: 2009-04-09
Also published as: CN101397048A

Abstract

An automatic speed variator for bicycle is composed of a speed changing transmission device and a speed changing control device. The speed changing transmission device is a three-level planetary gear device (4-6) that is coaxial with the main axle. The speed changing control device includes a normally engaged output pallet (11) and two normally disengaged control pallets (12,13), and a centrifugal block balance disk (20) that controls the pallet and ratchet engagement. The output pallets are provided uniformly on the out circumference of the internal gear ring of the planetary gear and controlled by three-level reposition springs (19). The centrifugal block balance disk (20) includes a fixed disk (42) and a swing lever disk (45) that is radically fixed to the fixed disk. The swing lever disk (45) is hinged to the control pallet (12,13) by the shifting lever (42,48), the pallet-shifting lever (24,25). An arc recess is provided on the movement path defined by the pallet-shifting lever sliding and swing along the reposition spring. A roller bearing is provided between the swing lever disk (45) and the fixed disk (42).

Description

Bicycle automatic transmission technology field

The present invention relates to a transmission structure, and more particularly to an improved structure of a bicycle automatic transmission. Background technique

In the prior art, a Chinese utility model patent (Patent No.: ZL 2004 2 0070090.3) discloses a solid axle bicycle automatic transmission which is changed in the axial direction by a flexible pull sleeve and is different from the planetary gear train by a cross wheel. The input mode, and the shift control device must pass through a series of transmissions in the axial direction, so that a large axial transmission resistance is generated, resulting in inflexible shifting; the shifting device has a planetary gear train, and the shifting is realized by changing the input position. In the low, medium and high speed positions, the gear cross wheel is the driving component of the transmission. There is a large coupling force between the gear cross wheel and the transmission component of the planetary gear train. Only when this combination force is released can the edge be realized. The axial shift shifting shifting, therefore, when the speed is changed to reach the shifting request, the pedal is slowly slammed, and the transmission coupling force between the gear cross wheel and the gear position is released to realize automatic shift shifting, resulting in shifting. Control is difficult.

- Chinese invention patent application (Application No.: 200610046543.2) discloses an improved automatic bicycle transmission, which is mainly composed of a variable speed transmission and a shift control device. Wherein: the shifting transmission device is a three-stage planetary gear train structure coaxial with the main shaft, and the shifting control device comprises a planetary gear train with a uniform outer ring of the inner ring of the planetary gear train, three stages of the normally engaged output pawl controlled by the return spring and the normally off The control pawl of the opening action controls the centrifugal block balance plate of the pawl and the ratcheting movement, wherein the centrifugal block balance plate comprises a fixed disk and a pendulum plate mounted on the shaft diameter of the fixed disk, and the pendulum plate is connected through the gear The lever and the pawl pull lever are hinged to the control pawl. Although the shift control device can overcome the inflexibility caused by the large axial transmission resistance and the transmission coupling force between the gear cross wheel and the gear position, the shifting function is difficult, and the shifting function of the transmission is better realized. Action, but still has the following shortcomings:

1. The return spring action is not reliable. Since the main function of the return spring is to complete the engagement of the disengagement pawl and the ratchet, in the process of frequent swinging of the pawl, the return spring having a longer cantilever and a larger sliding stroke on the back of the pawl must ensure stability with the back of the pawl. And reliable contact. However, because the back of the pawl in the transmission is a completely smooth curved surface, the longer cantilever of the return spring cannot be stably positioned, and the phenomenon of slipping off the pawl during the very frequent swinging process will cause complete failure of the shifting action of the transmission. As a result, the entire transmission transmission is stuck and the transmission element is damaged.

2. The centrifugal block balance plate is not reliable. Since the centrifugal block balance plate is the core of the entire shift control device, and each drive mechanism of the shifting action element (such as the pawl and the pawl toggle lever) is completed, the sensitivity and the accuracy of the action of the centrifugal block balance plate determine The consistency of the transmission's shifting action, that is, the size of the individual shifting action of the transmission is completely determined. In this type of transmission, the rotary substructure having a plane friction between the swinging shaft and the fixed disc that controls the movement of the link hinged by the centrifugal block is controlled (where: the fixed disc is The main body of the centrifugal block balance disc; the swing rod disc is located on the outer circumference of the shaft diameter of the fixed disc, and the disc hole on the swing rod disc is connected with the pawl shifting rod through the gear connecting rod), so the friction force is large during work . In addition, various factors such as the degree of flatness (such as flatness, coaxiality, and axial pressing force) and the surface roughness of the part can also cause uncoordinated components and large individual differences in the components that complete the shifting action.

3. Centrifugal mass balance accuracy is low. In such a transmission, a component that completes the swinging motion in the centrifugal mass balance plate, that is, a flat friction pair is formed between the swinging plate and the fixed disk, and the pendulum disk and the fixed disk must form a certain radial direction between the rotating circumferential surfaces. The gap, which inevitably causes the uncertainty of the center of rotation of the centrifugal block, naturally forms a varying radius of rotation, so that the symmetrically arranged centrifugal block can not achieve mass balance, resulting in the radial positioning of the pendulum disk, which ultimately makes the transmission unable to form a certain Variable speed action. Summary of the invention

In order to overcome the above disadvantages, an object of the present invention is to provide a bicycle automatic transmission having high speed control and high reliability.

In order to achieve the above object, the technical solution of the present invention comprises: a shifting transmission device and a shifting control device, wherein: the shifting transmission device is a three-stage planetary gear train structure coaxial with the main shaft, and the shift control device includes a planetary gear train inner ring gear. The outer circumference is evenly distributed, the three-stage output engaging pawl controlled by the return spring and the control pawl of the normally disengaging action, and the centrifugal block balance disc which controls the engagement of the pawl and the ratchet, wherein the centrifugal block balance disc includes a fixed disk and a swing plate mounted on a shaft diameter of the fixed disk, the swing plate is hinged to the control pawl through the gear link and the pawl pull lever; and the pawl is pulled and swinged along the return spring a concave arc groove is added to the movement track; a rolling bearing is added between the shaft diameter of the pendulum plate and the fixed plate;

The rolling bearing is respectively installed between the swinging plate of the second to third planetary gears and the shaft diameter of the fixed disc; an adjusting pad is arranged between the rolling bearing; the outer ring of the rolling bearing is provided with a retaining ring, and the axial limit of the swinging plate is used The rolling bearing has an inner diameter of 22 mm to 25 mm, an outer diameter of 28 mm to 31 mm, and a bead diameter of 1.0 mm to 1.5 mm.

The present invention has been improved on the basis of the basic structure disclosed in the Chinese invention patent application (200610046543.2), overcoming the three shortcomings of the transmission described in the prior art. The fully automatic transmission of the present invention not only has the advantages of three-speed planetary gear train structure with the same variable speed, easy shift control, and the like, and particularly has the following beneficial effects:

1. The invention processes a concave arc groove on the smooth track of the pawl along the sliding track and the swing formed by the return spring to ensure stable and reliable contact between the return spring and the back of the pawl, so that the return spring The movement is completely deterministic and stabilizes the pawl force, does not produce an eccentric load, and the return spring action has reliability, and also completely avoids the possibility that the return spring is slipped and the transmission action malfunctions.

2. The rolling bearing is used to replace the plane friction pair formed by the pendulum plate and the fixed plate, which realizes the high sensitivity of the centrifugal block balance plate action and the high precision of the action, and at the same time ensures the consistency of the shifting action of the transmission. The radial bearing of the rolling bearing of the invention is only within the range of 1/1000 nm, has radial positioning accuracy unmatched by any means, and can realize high-precision rolling friction with axial self-preloading function, and the friction thereof The coefficient is almost negligible In this way, the inconsistency of the shifting action elements and the large individual differences due to various factors such as the machining accuracy of the parts and the surface roughness of the parts can be completely eliminated. DRAWINGS

Figure 1-1 is a front view of a prior art bicycle automatic transmission;

Figure 1-2 is a front view of the bicycle automatic transmission of the present invention;

Figure 2 is a cross-sectional view taken along line A-A of Figure 1;

Figure 3 is a cross-sectional view taken along line B-B of Figure 1;

Figure 4 is a schematic cross-sectional view taken along the line C-C of Figure 1 (for the structure of the return spring and the pawl);

Figure 5 is a front elevational view of the centrifugal block balancing disk of Figure 1;

Figure 6 is a schematic cross-sectional view taken along the line E-E of Figure 5.

Figure Ί is a partial cross-sectional view of a prior art two-stage shift control;

Figure 8 is a partial cross-sectional view showing a prior art three-speed shift control;

Figure 9 is a schematic view of the position of a prior art return spring;

Figure 10 is a schematic view showing the structure of the return spring and the pawl of the present invention (the thorn portion is provided with a concave type I melon groove); Figure 11-1 is a modified structural view of the centrifugal block balance disk of the present invention;

Figure 11-2 is a cross-sectional view taken along line L-L of Figure 11-1;

Figure 12-1 is a schematic view of the structure of the rolling bearing;

Figure 12-2 is a cross-sectional view taken along the line M-M of Figure 11-1. detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

In FIGS. 1-2, 1-2, and 3-9, the bicycle automatic transmission of the present invention has an axle 1 for being placed on the rear axle position of the bicycle. Specifically, the axle of the outer end of the hub casing 2 is provided with a power input sprocket 3 There is a shifting transmission and a shifting control device on the axle in the hub housing as the shifting output hub. The shifting transmission device has first-stage to third-stage planetary gear trains 4-6 mounted coaxially with the axle, and the inner ring gear 9 of the primary planetary gear train is connected to the power input sprocket as an input end of the shifting device. The carrier 7 is a planetary carrier of the secondary planetary gear train; the inner ring gear 8 of the secondary planetary gear train is a planetary carrier of the tertiary planetary gear train; the outer circumference of the carrier of the primary planetary gear train, the secondary planetary gear The outer circumference of the inner ring gear and the outer circumference of the inner ring gear 10 of the three-stage planetary gear train are respectively provided with three ratchets of one, two and three stages as the three output ends of the shifting device; the inner circumferences of the hub shell are respectively There are three stages of pawls 11~13 matched with the above three ratchets, the shaft holes of the pawls are sleeved on the pawl shafts 14 on the inner circumference of the hub shell; the first stage pawls 11 are the normally engaged output pawls; The stage pawl 12 and the third stage pawl 13 are control pawls of a normally disengaged action (lever type), with the shaft hole 15 as a fulcrum, one end being a pawl tooth 16 and the other end being provided with an axial shifting hole 18 The ratcheting arm 17 and the pawl dialing arm are respectively connected with a resetting elastic for disengaging the pawl from the ratchet Spring 19. The shift control device includes a centrifugal block balance plate 20 connected to the hub and coaxial with the axle, and the centrifugal block is flat On the weighing plate, there are four centrifugal blocks (uniformly distributed along the circumference), and the opposite two centrifugal blocks are a group, which constitutes a secondary centrifugal block 22 and a tertiary centrifugal block 23 (the mass of the tertiary centrifugal block is smaller than that of the secondary centrifugal The mass of the block), the secondary centrifugal block and the tertiary centrifugal block are respectively connected with axially arranged secondary pawl levers respectively inserted in the axial shifting holes of the secondary pawl and the third-stage pawl The 24 and 3rd stage pawl lever 25, the second level pawl lever 24 and the third stage pawl lever 25 are hinged with the gear link (the second pawl lever 24 is hinged to the second gear link). The three-stage pawl lever 25 is hinged to the third-speed link, and each gear link is hinged to the swing plate through the hole. One end of the hub housing can be fitted with any type of universal brake drum 26.

See Figure 4 for a schematic diagram of the relationship between the return spring and the pawl of the transmission in the prior art. In order to make the return spring complete the disengagement of the pawl and the ratchet, the longer cantilever and the return spring with a larger sliding stroke on the back of the pawl ensure stable and reliable backing of the pawl during the frequent swinging of the pawl. In the contact, the present invention processes a concave arc groove on the smooth back of the pawl dial arm along the movement track formed by the sliding and swinging of the return spring (as shown in FIG. 10, wherein: 19 is a return spring, 30 A recessed arcuate groove on the arm 17 is pulled for the pawl of the pawl. The result is: The movement of the return spring is completely certain, and the force of the pawl is stabilized, the eccentric load is not generated, the action is reliable, and the possibility that the reset spring is slipped and the transmission action is prevented is completely avoided.

For the structure of the centrifugal block balance disc in the prior art, see Figures 5 and 6, wherein: 41 is a fixed disc, 42 is a third-speed link, and 43 is a circlip (for fixing the swing sub-structure between the swing wand and the gear link) Pins), 44 for the pin, 45 for the pendulum plate (annular hollow structure with ear holes), 46 for the friction plate (between the two pendulum plates), 47 for the circlip, 48 for the second gear Rod.

The invention adds a miniature high-precision rolling bearing between the pendulum disk and the fixed plate of the centrifugal block balance plate (see Fig. 11-1-11-2, 12-1-12-2, wherein: 49 is a retaining ring, 50 is The rolling bearing, 51 is an adjusting pad); the rolling bearing is installed between the swinging plate of the second to third planetary gears and the fixed disk, and an adjusting pad is arranged between the two rolling bearings. In addition, each rolling bearing outer ring is provided with a circular wire retaining ring for the axial limit of the pendulum plate. The rolling bearing of the present embodiment has a miniature size, an inner diameter of 23.5, an outer diameter of 29.5 mm _{, and a} bead diameter of 1.2.

The invention adopts a miniature high-precision rolling bearing to replace the plane friction pair formed by the pendulum plate and the fixed plate, thereby realizing the high sensitivity of the centrifugal block balancing plate action and the high precision of the action, and ensuring the consistency of the shifting action of the transmission. The positioning accuracy is as follows: The radial clearance of the rolling bearing is within 1/1000 mm. At the same time, because the bearing has the inner ring motion track, it has the rolling friction of the axial self-preloading function, and its friction coefficient is almost negligible. Excluding. Due to the high positioning accuracy, the uncoordinated and large shifting of the shifting action elements due to various factors such as the machining accuracy of the parts (such as the flatness, the coaxiality, the axial pressing force) and the surface roughness of the parts are avoided. Individual differences.

The three planetary gear trains of the shifting device constitute a three-stage output, and have three increasing speed ratios of low, medium and high respectively compared with the input end. Since the primary pawl is a normally engaged pawl, the secondary pawl and the tertiary pawl are normally disconnected pawls, and when riding a bicycle, the vehicle is driven from a standstill at a low speed ratio; when the bicycle reaches a certain speed , quality The large secondary centrifugal block first generates radial displacement due to centrifugal force, and the radial displacement of the secondary centrifugal block drives the axially mounted secondary ratcheting lever to move the secondary ratcheting arm, due to the pawl dialing arm The smooth back of the pawl is machined with a concave circular arc groove along the movement track formed by the sliding and swinging of the return spring, so that the secondary pawl overcomes the pressure of the return spring and the secondary ratchet under the condition that the force is evenly and stably stabilized. When the meshing is achieved, the bicycle can be used at a medium speed ratio; when the bicycle reaches a higher speed, the smaller mass three-stage centrifugal block will also have a radial displacement due to the centrifugal force, and the axial three-stage pawl lever The three-stage pawl dialing arm is moved so that the three-stage pawl overcomes the pressure of the return spring and is engaged with the three-stage ratchet under the condition that the force is evenly and stably, and the bicycle can ride at a high speed ratio.

Example 2

The rolling bearing may have an inner diameter of 22 mm, an outer diameter of 28 mm _{, and a} bead diameter of 1.0 mm. Example 3

The rolling bearing may have an inner diameter of 25 mm, an outer diameter of 3 lmm, and a bead diameter of 1.50 mm.

Claims

Claim

1 . A bicycle automatic transmission comprising a shifting transmission device and a shifting control device, wherein: the shifting transmission device is a three-stage planetary gear train structure coaxial with the main shaft, and the shift control device comprises a planetary gear train inner ring outer circumference Uniform, three-stage, normally-engaged output pawl controlled by a return spring and a control pawl that normally disengages, and a centrifugal block balance disk that controls the engagement of the pawl and the ratchet, wherein the centrifugal block balance disk includes a fixed disk And a pendulum plate mounted on a fixed disk shaft diameter, the pendulum plate is hinged with the control pawl through the gear link, the pawl pull lever, and is characterized in that: the pawl toggle arm slides and swings along the return spring A concave arc groove is added to the formed motion track; a rolling bearing is added between the shaft diameters of the swing plate and the fixed plate.

A bicycle automatic transmission according to claim 1, wherein: ???said rolling bearings are respectively installed between the oscillating weight plates of the second to third stage planetary gears and the fixed disk shaft diameter.

3. The bicycle automatic transmission according to claim 1 or 2, characterized in that: an adjustment pad is provided between the rolling bearings.

4. The bicycle automatic transmission according to claim 1 or 2, wherein: the outer ring of the rolling bearing is provided with a retaining ring for axial limitation of the pendulum disk.

The bicycle automatic transmission according to any one of claims 1 to 4, characterized in that: the rolling bearing has an inner diameter of 22 mm to 25 mm, an outer diameter of 28 mm to 31 mm, and a bead diameter of 1.0 mm to 1.5 mni.