Bicycle inner transmission and bicycle

Abstract

The bicycle internal transmission can be installed in a five-way inner hole of a bicycle frame in a pressed mode and comprises a variable-speed shaft, a planetary gear transmission mechanism, a double-clutch mechanism and a bearing. When the variable-speed shaft rotates clockwise, direct power can be finally transmitted to the crankset through a third overrun clutch of the double-clutch mechanism, and when the variable-speed shaft rotates anticlockwise, the power can be transmitted to the crankset through a second overrun clutch of the double-clutch mechanism. The sun gear actively transmits speed reducing and torque increasing power to the crankset finally through the inner gear ring and the outer rings of the first overrunning clutch and the third overrunning clutch of the double-clutch mechanism, and a rider controls two different treading directions to achieve free switching of two power gears. The problem that a traditional bicycle cannot move forwards when pedaling backwards is solved.

Description

Technical Field

[0001] The present invention relates to an internal transmission for a bicycle and a bicycle. Background Art

[0002] Bicycles are low-carbon and environmentally friendly means of transportation commonly used in people's daily lives. In recent years, more and more people have participated in the green travel of cycling, and bicycles have become increasingly popular. However, existing bicycles must be pedaled forward to move forward. When pedaled backward, they either spin freely or move backward and cannot move forward. Summary of the Invention

[0003] The object of the present invention is to provide an internal transmission for a bicycle and a bicycle, which can also output power forward when the transmission shaft rotates counterclockwise or when the rider pedals backward to decelerate and increase torque, and can freely switch between two power gears by the rider controlling two different pedaling directions.

[0004] The present invention is implemented by adopting the following technical solutions: An internal transmission for a bicycle includes a transmission shaft, a planetary gear reduction mechanism, a dual clutch mechanism, a plurality of bearings, a chainring, and a flat key;

[0005] The planetary gear reduction mechanism includes a planet carrier, a sun gear, an internal gear ring, and a plurality of planet gears;

[0006] The dual clutch mechanism includes a first overrunning clutch, a second engaging portion, a third overrunning clutch, and a fourth output portion; The plurality of bearings includes a first bearing, a second bearing, and a third bearing;

[0007] The first bearing is press-fitted and installed in the inner hole of the planet carrier,

[0008] The second bearing is press-fitted and installed in the inner hole of the fourth output portion,

[0009] The third bearing can be press-fitted and fixedly installed in the inner hole of the bottom bracket of the bicycle frame,

[0010] The inner ring of the third bearing is installed on the outer circle of the second outer end portion of the fourth output portion;

[0011] The sun gear is integrally formed with the transmission shaft and is externally meshed with the plurality of planet gears. The plurality of planet gears are installed on the planet carrier and are internally meshed with the internal gear ring;

[0012] Both ends of the transmission shaft can be fixedly installed with a pair of cranks having a square hole or a spline structure;

[0013] The planet carrier, the internal gear ring, the first overrunning clutch, the second joint, the third overrunning clutch, the fourth output part, and the chainring are coaxially installed in sequence from the left end to the right end of the variable speed shaft. All the above overrunning clutches are standard parts of the same size, and both their inner and outer rings have key grooves. Among them, except that the second end face of the third overrunning clutch faces the left end of the variable speed shaft, the first end faces of the others all face the left end of the variable speed shaft; there is also a collar on the outer circumference of the variable speed shaft. The outer diameter of the collar is the same as the inner diameter of the overrunning clutch, and there is also a key groove on the collar. The key groove is connected to the inner key groove of the third overrunning clutch by a flat key; the first outer end face of the first overrunning clutch is integrally connected to the second outer end face of the internal gear ring. The second joint is used to bridge and connect the second inner end face of the first overrunning clutch and the second outer end face of the third overrunning clutch into one body. The first outer end face of the third overrunning clutch is integrally connected to the first outer end face of the fourth output part; the chainring is fixedly installed on the second outer end face of the fourth output part;

[0014] The planet carrier can be press-fitted and fixedly installed in the inner hole of the bottom bracket of the bicycle frame,

[0015] The outer diameters of the planet carrier and the third bearing are both larger than the outer diameters of the other components except the chainring; when the variable speed shaft rotates clockwise, the direct power is sequentially transmitted to the chainring through the key groove, the flat key, the inner ring of the third overrunning clutch, the outer ring of the third overrunning clutch, and the fourth output part. At the same time, the inner and outer rings of the first overrunning clutch and the internal gear ring are in an idling state; when the variable speed shaft rotates counterclockwise, the decelerated and torque-increased power is sequentially transmitted to the chainring through the sun gear driving the multiple planet gears, the internal gear ring, the outer ring of the first overrunning clutch, the inner ring of the first overrunning clutch, the second joint, the outer ring of the third overrunning clutch, and the fourth output part. At the same time, the inner ring of the third overrunning clutch is in an idling state.

[0016] Preferably, the multiple planet gears are 4 planet gears.

[0017] Preferably, the overrunning clutch of the dual clutch mechanism is a wedge overrunning clutch and the allowable torque is greater than or equal to 68 N·m.

[0018] Preferably, the connections between the end faces that are integrally connected are all welded.

[0019] Preferably, it further includes a plurality of steel balls. The second outer end face of the planet carrier further has a plurality of circular holes, and the circumference of the first outer end face of the internal gear ring further has semi-circular grooves. The second outer end face of the planet carrier and the first outer end face of the internal gear ring are in clearance fit; the plurality of steel balls are installed in the plurality of circular holes and the plurality of steel balls are tangentially engaged with the semi-circular grooves.

[0020] Preferably, the plurality of steel balls are four steel balls.

[0021] Preferably, the way of fixedly installing the chainring on the second outer end face of the fourth output part is spline movable connection and fixed installation with bolts or fixed installation by welding.

[0022] The present invention also provides a bicycle, and the bicycle internal transmission as described in any one of the above is press-fitted and fixedly installed in the through hole of the bottom bracket of the bicycle frame.

[0023] The beneficial effect of the present invention is that when the transmission shaft rotates counterclockwise or the rider pedals backward to decelerate and increase torque, power can also be output forward, and the rider can control two different pedaling directions to realize the free switching of two power gears.

[0024] The following further describes the implementation of the present invention in combination with the drawings and specific embodiments. Description of the Drawings

[0025] Figure 1 It is an exploded view of the bicycle internal transmission for realizing the present invention.

[0026] Figure 2 It is a partially transparent assembly diagram of the bicycle internal transmission for realizing the present invention.

[0027] Figure 3 It is a correct assembly diagram of the overrunning clutch of the bicycle internal transmission for realizing the present invention.

[0028] Reference numerals in the drawings: 1 - transmission shaft, 5 - chainring, 6 - flat key, 7 - a plurality of steel balls, 21 - planet carrier, 22 - sun gear, 23 - internal gear ring, 24 - at least three planet gears, 31 - first overrunning clutch, 32 - second engaging part, 33 - third overrunning clutch, 34 - fourth output part, 41 - first bearing, 42 - second bearing, 43 - third bearing Detailed Embodiments

[0029] In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0030] Examples of the embodiments are shown in the drawings, where like or similar reference numerals designate like or similar elements or elements having like or similar functions throughout.

[0031] In the description of the present invention, it should be understood that the terms "clockwise" and "counterclockwise" are only for the simplified description of the present invention. The so-called clockwise is equivalent to the rider pedaling forward, and the so-called counterclockwise is equivalent to the rider pedaling backward. It does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention. In addition, the terms "first", "second", "third", and "fourth" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. In the description of the present invention, unless otherwise specifically defined, the meaning of "a plurality" is two or more.

[0032] The terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium. It may be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0033] For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] Embodiment

[0035] See Figure 1 and Figure 2 , the present invention provides a specific embodiment of an internal bicycle transmission, including a transmission shaft 1, a planetary gear reduction mechanism, a dual clutch mechanism, a plurality of bearings, a chainring 5, and a flat key 6;

[0036] The planetary gear reduction mechanism includes a planet carrier 21, a sun gear 22, an internal gear ring 23, and a plurality of planet gears 24; the dual clutch mechanism includes a first overrunning clutch 31, a second engagement portion 32, a third overrunning clutch 33, and a fourth output portion 34;

[0037] The plurality of bearings includes a first bearing 41, a second bearing 42, and a third bearing 43;

[0038] Wherein the models of the first bearing 41 and the second bearing 42 are 61903, and the model of the third bearing 43 is 61809

[0039] The first bearing 41 is press-fitted into the inner hole of the planet carrier 21,

[0040] The second bearing 42 is press-fitted into the inner hole of the fourth output portion 34,

[0041] The third bearing 43 can be press-fitted and fixedly installed in the inner hole of the bottom bracket of the bicycle frame.

[0042] The inner ring of the third bearing 43 is installed on the outer circumference of the second outer end of the fourth output part 34.

[0043] The sun gear 22 has a thickness of 8 mm, a module of 0.8, and 24 teeth, is integrally formed with the transmission shaft 1, and is externally meshed with the multiple planet gears 24. The multiple planet gears 24 have a thickness of 8 mm, a module of 0.8, and 14 teeth, are installed on the planet carrier 21, and are internally meshed with the internal gear ring 23 which has a thickness of 8 mm, an outer diameter of 52 mm, and a module of 0.8 and 52 teeth.

[0044] Both ends of the transmission shaft 1 can be fixedly installed with a pair of cranks having a standard square hole or spline structure with a size of 12.6 mm. The outer diameter of the transmission shaft 1 is 17 mm and the length is 119.1 mm.

[0045] The planet carrier 21, the internal gear ring 23, the first overrunning clutch 31, the second engaging part 32 with an outer diameter of 52 mm, the third overrunning clutch 33, the fourth output part 34 with an outer diameter of 52 mm, and the chainring 5 with a thickness of 1.9 mm and 42 teeth are coaxially installed in sequence along the axial direction from the left end to the right end of the transmission shaft 1. The above overrunning clutches are all standard parts of the same size, and both their inner and outer rings have key grooves. Their model is CSK25PP or BCN255215. Among them, except that the second end face of the third overrunning clutch 33 faces the left end of the transmission shaft 1, the rest all have their first end faces facing the left end of the transmission shaft 1. Refer to Figure 3 , Figure 3 In, the installation states of the two overrunning clutches are shown by arrow symbols, one is clockwise and the other is counterclockwise. Among them, the correct installation state of the inner ring of the third overrunning clutch 33 in this embodiment is clockwise. There is also a ring platform on the outer circumference of the transmission shaft 1. The outer diameter of the ring platform is 25 mm, which is the same as the inner diameter of the overrunning clutch. There is also a key groove on the ring platform, and the key groove is connected to the inner key groove of the third overrunning clutch 33 by the flat key 6. The first outer end face of the first overrunning clutch 31 is connected to the second outer end face of the internal gear ring 23 as a whole. The second engaging part 32 is used to bridge and connect the second inner end face of the first overrunning clutch 31 and the second outer end face of the third overrunning clutch 33 as a whole. The first outer end face of the third overrunning clutch 33 is connected to the first outer end face of the fourth output part 34 as a whole. The chainring 5 is fixedly installed on the second outer end face of the fourth output part 34 and has a gap of about 0.1 to 0.3 mm from the third bearing 43.

[0046] The planet carrier 21 can be press-fitted and fixedly installed in the inner hole of the bottom bracket of the bicycle frame.

[0047] The outer diameters of both the planet carrier 21 and the third bearing 43 are 58 mm and are larger than the outer diameters of the other components except the chainring 5. When the transmission shaft 1 rotates clockwise, the direct power is sequentially transmitted to the chainring 5 through the keyway, the flat key 6, the inner ring of the third overrunning clutch 33, the outer ring of the third overrunning clutch 33, and the fourth output part 34. At the same time, the inner and outer rings of the first overrunning clutch 31 and the internal gear ring 23 are in an idling state. When the transmission shaft 1 rotates counterclockwise, the decelerated and torque-increased power is actively transmitted to the chainring 5 through the sun gear 22, the multiple planet gears 24, the internal gear ring 23, the outer ring of the first overrunning clutch 31, the inner ring of the first overrunning clutch 31, the second engaging part 32, the outer ring of the third overrunning clutch 33, and the fourth output part 34. At the same time, the inner ring of the third overrunning clutch 33 is in an idling state.

[0048] In this embodiment, to further ensure the reliability of the internal bicycle transmission, 4 planet gears 24 are adopted.

[0049] In this embodiment, the overrunning clutch can be a ratchet-pawl overrunning clutch or a friction overrunning clutch, such as a roller overrunning clutch or a wedge overrunning clutch. As a preference, in the embodiment of the present invention, a wedge overrunning clutch is adopted and the allowable torque is greater than or equal to 68 N·m, so that the internal bicycle transmission can operate normally.

[0050] In this embodiment, in order to reduce the size of the internal bicycle transmission, the connection mode between the connected end faces is all welded.

[0051] In this embodiment, the planet carrier 21 is always in a fixed state during operation, but its adjacent internal gear ring 23 is in motion. To prevent possible friction between the two, multiple steel balls 7 are installed in the multiple circular holes on the second outer end face of the planet carrier 21 and are tangent to the semicircular grooves on the circumference of the first outer end face of the internal gear ring 23, so that there is a gap of about 0.1 to 0.3 mm between the two end faces.

[0052] In this embodiment, considering the corresponding quantity designed for the multiple planet gears 24 in terms of structural design, the multiple steel balls 7 are preferably four steel balls 7.

[0053] In this embodiment, the preferred way to fixedly install the chainring 5 on the second outer end face of the fourth output part 34 is spline movable connection and fixed installation with bolts or preferably welded fixed installation, because welding can consider designing the dimensions of the components smaller and the weight lighter.

[0054] The present invention also provides a bicycle, in which the internal bicycle transmission described in any one of the above is fixedly installed by being pressed into the inner hole of the bottom bracket of the bicycle frame, and the bicycle can achieve effective shifting in any state.

[0055] The above are only the preferred embodiments of the present invention, rather than all embodiments. The patent scope of the present invention is not limited thereby. Any equivalent structural transformation made under the inventive concept of the present invention by using the content of the specification and drawings of the present invention is included in the patent protection scope of the present invention.

Claims

1. A bicycle internal transmission, characterized in that: It includes a variable-speed shaft (1), a planetary gear reduction mechanism, a dual-clutch mechanism, multiple bearings, a chainring (5) and a flat key (6); The planetary gear reduction mechanism includes a planet carrier (21), a sun gear (22), an internal gear ring (23) and multiple planet gears (24); the dual-clutch mechanism includes a first overrunning clutch (31), a second engaging portion (32), a third overrunning clutch (33) and a fourth output portion (34); The multiple bearings include a first bearing (41), a second bearing (42) and a third bearing (43); The first bearing (41) is press-fitted into the inner hole of the planet carrier (21); The second bearing (42) is press-fitted into the inner hole of the fourth output portion (34); The third bearing (43) can be press-fitted and fixedly installed in the inner hole of the bottom bracket of the bicycle frame; The inner ring of the third bearing (43) is installed on the outer circle of the second outer end portion of the fourth output portion (34); The sun gear (22) is integrally formed with the variable-speed shaft (1) and is externally meshed with the multiple planet gears (24), and the multiple planet gears (24) are installed on the planet carrier (21) and are internally meshed with the internal gear ring (23); Both ends of the variable-speed shaft (1) can be fixedly installed with a pair of cranks having a square hole or a spline structure; The planet carrier (21), the internal gear ring (23), the first overrunning clutch (31), the second engaging portion (32), the third overrunning clutch (33), the fourth output portion (34) and the chainring (5) are coaxially installed in sequence along the axial direction from the left end to the right end of the variable-speed shaft (1). The above overrunning clutches are all standard parts of the same size and both their inner and outer rings have key grooves. Among them, except that the second end face of the third overrunning clutch (33) faces the left end of the variable-speed shaft (1), the rest all have their first end faces facing the left end of the variable-speed shaft (1); there is also a ring platform on the outer circumference of the variable-speed shaft (1), the outer diameter of the ring platform is the same as the inner diameter of the overrunning clutch, and there is also a key groove on the ring platform. The key groove is connected to the inner key groove of the third overrunning clutch (33) by the flat key (6); the first outer end face of the first overrunning clutch (31) is connected to the second outer end face of the internal gear ring (23) as a whole, the second engaging portion (32) is used to bridge and connect the second inner end face of the first overrunning clutch (31) and the second outer end face of the third overrunning clutch (33) as a whole, and the first outer end face of the third overrunning clutch (33) is connected to the first outer end face of the fourth output portion (34) as a whole; the chainring (5) is fixedly installed on the second outer end face of the fourth output portion (34); The planet carrier (21) can be press-fitted and fixedly installed in the inner hole of the bottom bracket of the bicycle frame; The outer diameters of both the planet carrier (21) and the third bearing (43) are larger than the outer diameters of the remaining components except for the chainring (5); when the transmission shaft (1) rotates clockwise, the direct power is sequentially transmitted through the keyway, the flat key (6), the inner ring of the third overrunning clutch (33), the outer ring of the third overrunning clutch (33), and the fourth output part (34) to the chainring (5), while the inner and outer rings of the first overrunning clutch (31) and the internal gear ring (23) are in an idling state; when the transmission shaft (1) rotates counterclockwise, the decelerated and torque-increased power is actively transmitted through the sun gear (22) sequentially through the multiple planet gears (24), the internal gear ring (23), the outer ring of the first overrunning clutch (31), the inner ring of the first overrunning clutch (31), the second engaging part (32), the outer ring of the third overrunning clutch (33), and the fourth output part (34) to the chainring (5), while the inner ring of the third overrunning clutch (33) is in an idling state.

2. The internal bicycle transmission according to claim 1, wherein: The multiple planet gears (24) are 4 planet gears (24).

3. The internal bicycle transmission according to claim 1, wherein: The overrunning clutch of the dual clutch mechanism is a wedge overrunning clutch and the allowable torque is greater than or equal to 68 N·m.

4. The internal bicycle transmission according to claim 1, characterized in that: The connections between the end faces of the components connected as a whole are all welded.

5. The internal bicycle transmission according to claim 1, characterized in that: It further includes multiple steel balls (7). There are also multiple round holes on the second outer end face of the planet carrier (21). There is also a semi-circular groove on the circumference of the first outer end face of the internal gear ring (23). The second outer end face of the planet carrier (21) and the first outer end face of the internal gear ring (23) are in clearance fit; the multiple steel balls (7) are installed in the multiple round holes and the multiple steel balls (7) are tangentially engaged with the semi-circular groove.

6. The internal bicycle transmission according to claim 5, wherein: The multiple steel balls (7) are four steel balls (7).

7. The internal bicycle transmission according to claim 1, characterized in that: The chainring (5) is fixedly installed on the second outer end face of the fourth output part (34) in a spline movable connection and is fixedly installed with bolts or welded and fixed.

8. A bicycle, characterized in that: The internal bicycle transmission according to any one of claims 1 to 7 is press-fitted and fixedly installed in the inner hole of the bottom bracket of the bicycle frame.

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