KR101260050B1 - Mission - Google Patents

Abstract

PURPOSE: A transmission is provided to perform gear shift accurately without a clutch by using a ratchet. CONSTITUTION: A housing(102) comprises a plurality of planetary gears(140) along the axial direction. The plurality of planetary gears has a different gear ratio respectively. An input hub shaft(110) comprises a sprocket(11). The sprocket received a driving force in one side. The input hub shaft is extended through the axial direction in the housing. A plurality of input gears(130) is inserted into the input hub shaft. Circumferences of the plurality of input gears are geared to the plurality of planetary gears respectively. A ratchet unit(120) is installed on the input hub shaft along the axial direction. The ratchet unit transfers the rotary force of the input hub shaft to the input gear.

Description

Transmission {MISSION}

The present invention relates to a transmission which can be used for a bicycle, a motorcycle, an automobile or the like.

The transmission is a device that changes the speed or rotational force of a driving part mounted on an automobile or a bicycle. Generally, the transmission is equipped with a gear device and implements a desired number of stages according to the transmission ratio which is the difference between the input revolution speed and the output revolution speed. Transmissions are widely used in a variety of forms in industries, transport machines, devices and appliances where speed differences between input and output are required.

In the case of a conventional bicycle, a crankshaft with a pedal and a wheel drive shaft are connected by a chain, and the pressing force of the pedal is transmitted to the drive shaft of the wheel as rotational force. As the bike culture develops, there are also many cases where the bicycle is equipped with a transmission to implement various stages according to the terrain. A typical transmission mounted on a bicycle is a type in which a chain can be selectively hooked to a plurality of sprockets of different teeth. Such a shifting method is disadvantageous in that the operating lever is necessarily installed to change the sprocket, and there is a problem that the volume and weight also increase.

Unlike a form in which a sprocket having a different number of teeth outside is provided, a bicycle having a transmission gear built in a hub axis improves the appearance, but not only increases the price due to the complexity of the internal structure, And a clutch is required for automatic shifting.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a transmission capable of precisely shifting without using a clutch by using a ratchet.

According to an aspect of the present invention, there is provided a transmission including: a housing having a plurality of planetary gears having different gear ratios along an axial direction; An input hub shaft having a sprocket receiving a driving force at one side thereof and extending along the axial direction inside the housing; A plurality of input gears fitted to the input hub axes, the outer periphery thereof being engaged with the plurality of planetary gears, and arranged along the axial direction; And a ratchet wheel mounted on the input hub axle so as to be slidable along the axial direction and engaged with a corresponding one of the plurality of input gears at a slidable position to transmit the rotational force of the input hub axle to the corresponding input gear, Unit.

As an example related to the present invention, the transmission includes: an output gear installed at an output end of the plurality of planetary gears; And an output hub axis rotated by the output gear.

As an example related to the present invention, a hub gear is formed at one side of the output hub shaft to be engaged with the output gear, and the hub gear has a radius smaller than a distance between the center of the input hub shaft and the center of the planetary gear have.

As an example related to the present invention, the ratchet unit includes a ratchet holder slidably installed along the input hub axis; And a ratchet member provided on the ratchet holder and rotatably installed so that an end of the ratchet member is caught by a latching protrusion formed on an inner circumferential surface of the input gear.

As an example related to the present invention, guide grooves are formed along the axial direction on the outer peripheral surface of the input hub shaft, and the ratchet holder can be inserted into the guide grooves.

As an example related to the present invention, the transmission may further include an elastic member installed in the ratchet holder, and configured to provide an elastic force in a direction in which the ratchet member is extended.

In one embodiment of the present invention, one end of the ratchet member has an arcuate outer circumferential surface, and the ratchet holder may have an arc-shaped inner circumferential surface so as to guide the end of the ratchet member in a rotational direction.

In one embodiment of the present invention, one end of the ratchet member may be connected to the ratchet holder by a hinge shaft.

As an example related to the present invention, a recessed first seating groove may be formed on the latch jaw so that the end of the ratchet member can be seated.

As an example related to the present invention, a recessed second seating groove may be formed in the guide groove so that the end of the ratchet holder can be seated.

In this case, the first seating groove portion and the second seating groove portion may be offset from each other along the axial direction.

According to an embodiment of the present invention, a slot may be formed along the axial direction in the guide groove, and a guide protrusion formed to be slidable along the slot may be provided on the bottom surface of the ratchet holder.

As one example related to the present invention, the transmission includes a first cable having one end connected to the ratchet unit and the other end connected to an operating portion for manual operation; A return spring for providing an elastic force to return the ratchet unit to its original position when the tension of the first cable is removed; And a second cable connected to the return spring.

As an example related to the present invention, the transmission includes a third cable having one end connected to the ratchet unit; And a centrifugal weight connected to the other end of the third cable and installed so as to be movable in a radial direction in proportion to a rotational speed of the output hub shaft.

As an example related to the present invention, the plurality of planetary gears may be installed on a planetary gear shaft fixed to the housing.

Further, a transmission according to the present invention includes: a sprocket receiving a driving force; A plurality of planetary gears configured to be revolvable by the rotational force of the sprocket and having different gear ratios along the axial direction; A plurality of input gears arranged in the center of the planetary gears so as to be able to engage with the plurality of planetary gears and arranged along the axial direction; And a plurality of ratchet units arranged along the axial direction on the outer circumference and configured to selectively protrude the plurality of ratchet units so that the ratchet unit can be selectively hooked to the input gear.

In one embodiment of the present invention, the shaft is formed so as to be connected and rotated by a cable, and at one side of the shaft, a latching groove for each angular position corresponding to each of the ratchet units and a latching member for latching the latching groove are provided .

According to the one transmission relating to the present invention, since the rotational force is transmitted to the peripheral input gear by the ratchet unit that is slid, the ratchet unit provides the power transmission with certainty and accuracy of the shift. Such a sliding ratchet unit is effective not only for a manual shift but also for an automatic shift without a clutch.

As an example related to the present invention, it is possible to provide the shift accuracy by allowing the ratchet member or the ratchet holder to be hooked to the first seating groove portion or the second seating groove portion.

As another example related to the present invention, the ratchet unit is connected by a centrifugal weight so that automatic shifting is possible without any additional power.

1 is a conceptual diagram schematically showing a transmission 100 according to the present invention.
2 is a schematic cross-sectional view showing the relationship between the input gear 130 and the planetary gear 140 according to the present invention
3 is a cross-sectional view schematically showing the configuration of the ratchet unit 120 related to the present invention.
FIG. 4 is a conceptual diagram illustrating the principle of precise shifting by the ratchet holder 121 and the ratchet member 122,
5 is a conceptual view showing the principle of the configuration of the transmission 200 according to another example related to the present invention.
6 is a conceptual diagram for explaining the relationship between the shaft 251 of FIG. 5, the ratchet unit 220 and the engaging groove 280. FIG.
Figure 7 is a schematic cross-sectional view of the shaft 251 and the ratchet unit 220 of Figure 6

Hereinafter, a transmission relating to the present invention will be described in detail with reference to the accompanying drawings.

1 is a conceptual diagram schematically showing a transmission 100 relating to the present invention.

1, the transmission 100 is configured such that the driving force transmitted through the input hub shaft 110 is converted into the rotational force of the input gear 130 and the planetary gear 140 and then transmitted to the output gear 150 and the output hub 150. [ And is configured to be output through the shaft 160. In this process, the ratchet unit 120 slides on the input hub shaft 110 and can change the stage. Hereinafter, the configuration and operation of each component will be described in detail.

Here, the transmission 100 can be widely used not only in the transportation field of bicycles, motorcycles, or other automobiles, but also in home or industrial devices or apparatuses. Also, as will be described later, the transmission 100 can be applied to both the "automatic shift" method in which the gear is automatically changed in accordance with the speed and the "manual shift" have.

The input hub shaft 110 has a sprocket 111 on one side and extends along the axial direction to the inside of the housing 102. When the sprocket 111 is mounted on a bicycle, a motorcycle or the like, the sprocket 111 can receive the rotational force of a crankshaft connected to a prime mover or a pedal by a chain. In some cases, the sprocket 111 can be replaced by a mechanical element such as a gear or a pulley. The housing 102 is provided with a bearing at each position for rotatably supporting the input hub shaft 110 and the planetary gear 140.

The ratchet unit 120 is slidably supported on the input hub shaft 110. The detailed configuration of the ratetchet unit 120 and the relationship with the input hub axis 110 will be described in detail later with reference to FIG. The ratchet unit 120 serves to transmit the rotational force of the input hub shaft 110 to the input gear 130 at a sliding position.

The input gear 130 is composed of a number of gears corresponding to the number of stages to be realized by the movement of the ratchet unit 120. Each of the input gears 130 is fitted in the input hub shaft 110 and is arranged to gradually decrease or increase the gear ratio therebetween. The input gear 130 engaged by the ratchet unit 120 is restrained by the input hub shaft 110 to transmit the rotational force to the corresponding planetary gear 140 but the input gear 130 Rotate idle on the input hub axis 110. A plurality of engagement protrusions 132 are formed on the inner periphery of the input gear 130 so that the ratchet unit 120 can be engaged.

The planetary gears 140 are arranged along the axial direction with a number corresponding to each of the input gears 130 arranged at different gear ratios and arranged to engage with the respective input gears 130. Accordingly, the planetary gears 140 are arranged in the direction opposite to the arrangement of the input gears 130 in terms of the gear ratios.

Fig. 2 shows the relationship between the input gear 130 and the planetary gear 140. Fig. That is, as shown in FIG. 2, the planetary gear 140 is disposed around the input gear 130. However, the planetary gear 140 is in a state of 'rotating' in place, and is different from a method of revolving around the input gear 130, that is, 'idling'. That is, the planetary gear 140 is installed on the planetary gear shaft 141 which is 'fixed' (rotatable but fixed in position) to the housing 102. The planetary gear 140, which receives the rotational force of the input gear 130, transmits the planetary gear 140 to the planetary gear shaft 141. The planetary gear 140 may be disposed at a plurality of positions around the input gear 130. In Fig. 2, three planetary gears 140 are arranged. However, the arrangement of the planetary gears may be disposed at only one position around the input gear 130, or at two or four or more positions.

1, an output gear 150 for receiving the rotational force of the planetary gear 140 is disposed at one end of the planetary gear shaft 141. [ A hub gear 161 for receiving the rotational force of the output gear 150 is provided at one side of the output hub shaft 160. The hub gear 161 is adapted to be engaged with the output gear 150 and has a smaller radius than the distance between the center of the input hub shaft 110 and the center of the planetary gear 140. Since the hub gear 161 is surrounded by the output gears 150, it is possible to realize a high rotation speed in the case of transmitting power to the ring gear that is in contact with the planetary gear.

The output hub shaft 160 is connected to a structure 103 such as a wheel to finally transmit rotational force to a wheel or the like.

The ratchet unit 120 is able to transmit the rotational force of the input hub shaft 110 to the corresponding input gear 130 at a sliding position while moving axially along the input hub shaft 110. [ An automatic or manual mechanism may be installed to change the position of the ratchet unit 120. [ The first cable 171 connected to the ratchet unit 120 may be installed so that the user can manually pull the first cable 171. The pulled ratchet unit 120 is returned to the opposite side of the first cable 171 by the elastic force The second cable 172 and the return spring 174 can be mounted. The ratchet unit 120 can be moved to the high-end position by pulling the first cable 171 at the lower end position. When the tension of the first cable 171 is removed, the return spring 174 moves the ratchet unit 120 120 are moved in opposite directions.

The ratchet unit 120 is connected to the third cable 173 so as to be automatically shifted according to the rotational speed of the output hub shaft 160. The third cable 173 is connected to the centrifugal weight 175 disposed so as to be movable in the centrifugal direction along the guide 176 as the rotational speed of the output hub shaft 160 increases. When the rotation speed of the output hub shaft 160 is increased, the centrifugal weight 175 is moved in the direction away from the center, so that the third cable 173 pulls the ratchet unit 120 and moves toward the high end. Conversely, when the rotational speed of the output hub shaft 160 decreases, the ratchet unit 120 and the centrifugal weight 175 are moved to their original positions by the elastic restoring force of the return spring 174. [

3 is a cross-sectional view schematically showing the configuration of the ratchet unit 120 related to the present invention. At least one guide groove 112 is formed along the axial direction on the outer periphery of the input hub shaft 110 disposed inside the input gear 130. The ratchet unit 120 slides along the guide groove 112, . 3 shows a state of the ratchet unit 120 hung on the corresponding input gear 130 at a specific position of the plurality of input gears 130 slid.

The ratchet unit 120 includes a ratchet holder 121 slidably installed along the input hub shaft 110 and a ratchet member 122 mounted on the ratchet holder 121. The ratchet holder 121 serves as a carrier for moving the ratchet member 122. However, the ratchet holder 121 may be excluded from the configuration of the ratchet unit 120 as the case may be. In this case, the rotational force of the input hub shaft 110 is transmitted to the input gear 130 with only the ratchet member 122 without the ratchet holder 121.

The ratchet member 122 is rotatably installed so that the end of the ratchet member 122 can be caught by the engaging jaw 132 of the input gear 130. The ratchet member 122 may be connected to the ratchet holder 121 by a hinge shaft 127 in order to rotate the ratchet member 122. [ One end of the ratchet member 122 may have an arc-shaped outer circumferential surface 128 for the rotation of the ratchet member 122. The ratchet holder 121 may be configured to rotate the end of the ratchet member 122 And may have an arc-shaped inner circumferential surface 129. The ratchet member 122 is laid down when the ratchet holder 121 moves from one gear position to the adjacent gear position or does not transmit power and is rotated when the power is transmitted to be caught by the engagement protrusion 132. [ An elastic member 123 may be provided on the ratchet holder 121 to provide an elastic force in a direction in which the ratchet member 122 is extended. The elastic member 123 may be formed in the form of a leaf spring or the like. However, the elastic member 123 may be omitted from the configuration of the ratchet unit 120, and power transmission may be performed only by the ratchet member 122 without using the elastic member 123. [

A slot 113 is formed in the guide groove 112 along the axial direction and a guide protrusion 125 formed to be slidable along the slot 113 is formed on the bottom surface of the ratchet holder 121. The guide protrusion 125 is restrained by a slider 126 slidably installed along the outer circumferential surface of the stationary shaft 101. The slider 126 slides along the first cable 171 and the second cable 172, And the third cable 173. When the first cable 171, the second cable 172 or the third cable 173 is moved, the slider 126 and the guide protrusion 125 move, and the ratchet holder 121 moves accordingly. The width of the slot 113 may have a width such that it is not disturbed by the flow of the guide protrusion 125 because the ratchet holder 121 can be moved along the circumferential direction in the guide groove 112. [

FIG. 4 is a conceptual view showing an accurate shifting principle by the ratchet holder 121 and the ratchet member 122 according to an embodiment of the present invention. The engagement protrusions 132 formed on the input gears 130 may have a profile as shown in FIG. 4 when they are in the same phase. The latching jaw 132 is formed with a concave first seating groove portion 132a so that the end of the ratchet member 122 can be seated. The end portion of the ratchet member 122 may also be formed in a rounded shape 122a. The first seating groove portion 132a and the rounded end portion 122a of the ratchet member 122 are arranged such that when the ratchet member 122 is between one input gear 130 and the adjacent input gear 130, The gear 130 is guided to enter only one of them.

The guide groove 112 formed in the input hub shaft 110 may also have a recessed second seating groove 112a such that the ratchet holder 121 is located at a specified position among a plurality of positions. The ends of the ratchet holder 121 may also be formed in a rounded shape 121a. The second seating groove portion 112a and the round end portion 121a of the ratchet holder 121 are positioned such that the ratchet holder 121 is connected to the input gear 130 adjacent to the input gear 130, So that only one of the two input gears 130 is guided to enter.

It is possible that only one or both of the first seating groove portion 132a and the second seating groove portion 112a are formed. In the latter case, the first seating groove portion 132a and the second seating groove portion 112a may be offset from each other. When the ratchet member 122 is in the middle of the adjacent two input gears 130, the ratchet holder 121 is offset from the middle by the offset S, And is quickly moved to any one end by the guide action between the groove portions 112a. The offset S is of the order of one millimeter or less and is such that the ratchet member 122 and the ratchet holder 121 are exactly at an intermediate position of the offset S, Can be set to a distance.

5 is a conceptual view showing the principle of the structure of the transmission 200 according to another example of the present invention. Fig. 6 is a view showing the relationship between the shaft 251 of Fig. 5 and the ratchet unit 220 and the engagement groove 280 FIG. 7 is a schematic sectional view of the shaft 251 and the ratchet unit 220 of FIG. 6; FIG.

The transmission 200 shown in these drawings has a sprocket 211, a planetary gear 240, an input gear 230, a ratchet unit 220 and a shaft 251. Hereinafter, these configurations will be described.

The sprocket 211 is fixed to the planetary gear shaft 241 unlike the previous embodiment and revolves the planetary gear shaft 241.

The planetary gears 240 are arranged to have different gear ratios along the axial direction. The planetary gear 240 may be connected to a separate output gear as in the previous embodiment or may be connected to a ring gear separately disposed on the periphery of the planetary gear 240. [

A plurality of input gears 230 are arranged along the axial direction like the planetary gears 240. The input gear 240 is arranged to have an opposite tooth ratio to the planetary gear.

The input gear 230 is freely rotatably mounted to the shaft 251. However, when engaged by the ratchet unit 220, the corresponding input gear 230 is restrained by the fixed shaft 251, and the planetary gear 240 is revolved with the corresponding tooth ratio.

The ratchet unit 220 is arranged on the outer periphery of the shaft 251 along the axial direction. Exposure holes 252 are formed in the shaft 251 so that the selected one of the plurality of ratchet units 220 may be exposed.

The shaft 251 is connected by a plurality of cables 271, 272, and 273, and can rotate at a predetermined angle. Thus, the plurality of ratchet units 220 selectively engage the input gear 230 with the shaft 251.

According to Fig. 6, the exposure holes 252A, 252B, and 252C are arranged along the axial direction and the circumferential direction. The ratchet units 220a, 220b, 220c, 220d, 220e and 220f arranged inside are selectively exposed through the exposure holes 252A, 252B and 252C and are constrained to the corresponding input gear 230 at the time of exposure.

One side of the shaft 251 is provided with engaging grooves 280A, 280B and 280C for each angular position corresponding to each of the ratchet units 220 and a retaining piece 291 for engaging with the engaging grooves 280A, 280B and 280C. The sprocket 211 or the fixed housing or the like may include the operation protrusion 290 so that the catch 291 is automatically engaged in the catch groove 280. [ When the sprocket 211 is rotated and the operating projection 290 comes into contact with the latching piece 291, the latching piece 291 is pushed by the operating projection 290 and caught by the corresponding latching grooves 280A, 280B and 280C Loses. The engaging grooves 280A, 280B, and 280C and the engaging pieces 291 prevent the shaft 251 from being located at a position between any one of the adjacent ratchet units. The engaging groove or engaging piece may have a shape or structure different from that shown in Figs. As an example, the engagement groove or the engagement piece may be disposed on the side of the sprocket 211, not on the shaft 251, or on the outer side of the transmission 200. [ These engaging grooves 280A, 280B and 280C and the engaging piece 291 essentially prevent the power transmission between the input gear 230 and the input gear 230 from occurring.

8 is a conceptual view showing the relationship between the latching groove 380 and the latching piece 391 according to another example related to the present invention. In this example, the spring 393 and the mover 392 are provided so that the latching piece 391 is caught in the latching groove 380 or can be separated from the latching groove 380. The spring 393 is provided so as to apply an elastic force to the mover 392 toward the mover 390. The movable member 392 is in a state of being engaged with the operating projection 390 by the pushing force of the spring 393 when the sprocket 311 is rotated by receiving the driving force. On the other hand, when the sprocket 311 is not rotated, the mover 392 is moved to the left while pushing the spring 393 by the wedge action of the actuating projection 390. The mover 392 pushes the latching piece 391 to be caught in the latching groove 380 while being moved. Here, each latching groove 380 is a step, and an end corresponding to the latching groove 390 in which the latching piece 391 is located is realized. By this configuration, the latching piece 391 is caught by the corresponding latching groove 390, so that the step can be changed naturally.

The transmission described above is not limitedly applied to the configuration and method of the illustrated embodiments. The embodiments may be configured so that all or some of the embodiments may be selectively combined so that various modifications may be made.

100: transmission 101: stationary shaft
102: housing 110: input hub axis
111: Sprocket 112: Guide groove
113: Slot 120: Ratchet unit
121: ratchet holder 122: ratchet member
123: elastic member 130: input gear
132: engagement jaw 140: planetary gear
141: planetary gear shaft 150: output gear
160: Output hub shaft 161: Hub gear
171: first cable 172: second cable
173: third cable 174: return spring
175: Centrifugal Weights 176: Guide

Claims (17)

A housing provided with a plurality of planetary gears having different gear ratios along the axial direction;
An input hub shaft having a sprocket receiving a driving force at one side thereof and extending along the axial direction inside the housing;
A plurality of input gears fitted to the input hub axes, the outer periphery thereof being engaged with the plurality of planetary gears, and arranged along the axial direction; And
A ratchet unit mounted to be slidable along an axial direction on the input hub axis and engaged with a corresponding input gear of the plurality of input gears in a slidened position to transmit the rotational force of the input hub axle to the corresponding input gear, of,
Included, transmission.
The method according to claim 1,
An output gear installed at an output end of the plurality of planetary gears; And
Further comprising an output hub axis that is rotated by the output gear.
3. The method of claim 2,
A hub gear engaged with the output gear is formed at one side of the output hub shaft,
The hub gear having a radius less than a distance between the center of the input hub axis and the center of the planetary gear.
The method according to claim 1,
The ratchet unit includes:
A ratchet holder slidably installed along the input hub axis; And
And a ratchet member installed on the ratchet holder so as to be rotatable so that an end portion of the ratchet member is caught by an engagement protrusion formed on an inner circumferential surface of the input gear.
5. The method of claim 4,
Wherein a guide groove is formed along the axial direction on the outer peripheral surface of the input hub shaft, and the ratchet holder is inserted into the guide groove.
5. The method of claim 4,
And a resilient member provided on the ratchet holder and formed to be capable of providing an elastic force in a direction in which the ratchet member is extended.
5. The method of claim 4,
Wherein one end of the ratchet member has an arc-shaped outer peripheral surface, and the ratchet holder has an arc-shaped inner peripheral surface for rotatably guiding an end portion of the ratchet member.
5. The method of claim 4,
And one end of the ratchet member is connected to the ratchet holder by a hinge shaft.
6. The method of claim 5,
And a recessed first seating recessed portion is formed on the engagement protrusion so that an end of the ratchet member can be seated.
10. The method of claim 9,
And a second recessed groove is formed in the guide groove so that an end of the ratchet holder can be seated.
11. The method of claim 10,
And the first seating groove portion and the second seating groove portion are mutually offset along the axial direction.
6. The method of claim 5,
A slot is formed in the guide groove along the axial direction,
And a guide protrusion formed on the bottom surface of the ratchet holder so as to be slidable along the slot.
The method according to claim 1,
A first cable having one end connected to the ratchet unit and the other end connected to an operating portion for manual operation;
A return spring for providing an elastic force to return the ratchet unit to its original position when the tension of the first cable is removed; And
A second cable connected to the return spring,
Further included, the transmission.
3. The method of claim 2,
A third cable whose one end is connected to the ratchet unit; And
A centrifugal weight connected to the other end of the third cable and movable in a radial direction in proportion to a rotation speed of the output hub shaft,
Further included, the transmission.
The method according to claim 1,
Wherein the plurality of planetary gears are provided on a planetary gear shaft fixed to the housing.
A sprocket receiving a driving force;
A plurality of planetary gears configured to be revolvable by the rotational force of the sprocket and having different gear ratios along the axial direction;
A plurality of input gears arranged in the center of the planetary gears so as to be able to engage with the plurality of planetary gears and arranged along the axial direction; And
A plurality of ratchet units arranged along an axial direction on an outer periphery thereof and configured to selectively protrude the plurality of ratchet units so that the ratchet unit can be selectively hooked to the input gear, .
17. The method of claim 16,
The shaft is formed to be rotatable by being connected by a cable,
Wherein the shaft has a latching groove for each angular position corresponding to each of the ratchet units and a latching portion for latching the latching groove on one side of the shaft.

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