TWM452134U - Derailleur - Google Patents

Abstract

A derailleur suitable for installing to a bicycle is provided. The derailleur includes a transmission module, a linkage mechanism, a chain-guide and a torsion limitation module. The transmission module includes a body and a transmission axis. The linkage mechanism is fixed to the transmission module. The chain-guide is fixed to the linkage mechanism. The torsion limitation module includes a transmission element fixed to the transmission axis, a driven element connected to the linkage mechanism and an elastic element disposed between the transmission element and the driven element. When the transmission axis is driven by the body to rotate along an axis, the transmission axis drives the linkage mechanism to move through the elastic element leans the transmission element and the driven element. When the transmission axis is driven by the body to rotate along the axis but the linkage mechanism can't move, the transmission element moves relative to the driven element through twisting the elastic element along the axis.

Description

transmission

The present invention relates to a transmission, and more particularly to a front derailleur for a bicycle.

In recent years, the bicycle market has flourished, and both high-end bicycles of competition type and mass-type bicycles for leisure and entertainment have been favored by consumers. In general, the bicycle is often equipped with a transmission so that the bicycle can move the chain to different chainrings depending on the terrain and user needs. The transmission includes a front derailleur and a rear derailleur, wherein the front derailleur is disposed on the frame of the bicycle to control the position of the chain on the chain ring. Bicycles can be used with different front derailleurs depending on the frame structure or shifting line. In addition to the mechanical transmission, many bicycles are gradually adopting electronic transmissions.

The interior of the electronic transmission has a motor and gear set in which the motor is powered and transmitted to the drive shaft via the gear set. When the motor drives the drive shaft to rotate, the drive shaft drives the link mechanism, thereby causing the link mechanism to drive the chain guide to adjust the chain. Therefore, there is a linkage relationship between the link mechanism and the drive shaft. However, when the chain and the toothed disc are stuck and the chain guide and the link mechanism are unable to move, if the motor continues to drive the drive shaft to rotate, the rotating drive shaft generates torque with respect to the link mechanism. This torque rotates the gear set or motor via the drive shaft, causing damage to the gear set or motor.

US Patent No. US7291079 proposes a forward change of a motorized bicycle A speeder assembly that is provided with a jamming protection device on a motorized link that connects the motor. The motorized link is coupled to the drive shaft via a snap guard to transmit a rigid force connection relationship to move the chain guide. When the chain guide is jammed, the motorized link forms a connection relationship with the drive shaft through the snap guard to transmit a non-rigid force to continuously operate the drive shaft. U.S. Patent No. 7,442,136 discloses a front derailleur assembly for a motorized bicycle that is provided with a snap guard on a motorized link that connects the motor. The snap guard can allow the drive shaft to continuously rotate to drive the transmission member when the guide link cannot move, so as to prevent the drive shaft from generating torque with respect to the link mechanism and destroying the motor connected to the drive shaft.

The present invention provides a transmission having a mechanism to prevent damage to the transmission due to the chain and the chainring being stuck.

The present application proposes a transmission suitable for mounting to a bicycle. The transmission includes a transmission module, a link mechanism, a guide chain and a torque limiting module. The transmission module includes a body and a transmission shaft. The body is adapted to be fixed to a frame of the bicycle, and the transmission shaft is coupled to the body and driven to rotate by the body. The link mechanism is fixed to the transmission module and is driven by the transmission shaft to move relative to the body. The chain guide is fixed to the link mechanism and is driven by the link mechanism to be adapted to move a chain of the bicycle. The torque limiting module includes a transmission member, a linkage member and an elastic member. The transmission member is fixed to the transmission shaft and moves synchronously with the transmission shaft. The linkage is connected to the linkage mechanism. The elastic member is disposed between the transmission member and the linkage member. When the drive shaft is driven by the body When the shaft rotates, the transmission shaft moves the link mechanism relative to the body via the elastic member against the transmission member and the linkage member. When the drive shaft is driven by the body to rotate in the axial direction but the link mechanism is incapable of moving, the transmission member moves relative to the link member by twisting the elastic member along the axial direction.

In one embodiment of the present invention, when the drive shaft is rotated in the axial direction, the drive shaft drives the link mechanism to move relative to the body along the axial direction.

In an embodiment of the present invention, when the drive shaft rotates in the first clock direction along the axial direction, the link mechanism moves relative to the body along the axial direction toward the first clock direction, and when the drive shaft is axially opposite to When a second clock direction of the first clock direction is rotated, the link mechanism moves relative to the body in the second clock direction along the axial direction.

In an embodiment of the present invention, the elastic member has a preload so that the two ends of the elastic member respectively abut against the transmission member and the linkage member. When the transmission member and the linkage member move synchronously, the transmission member is preloaded. When the linkage is driven, when the transmission member and the linkage member move relative to each other, the transmission member twists the elastic member.

In an embodiment of the present invention, the transmission member is a first sleeve, the linkage member is a second sleeve, and the second sleeve and the elastic member are respectively sleeved on the transmission shaft, and the first sleeve is fixed to the first sleeve. The drive shaft is sleeved on the second sleeve to form a space to accommodate the elastic member.

In an embodiment of the present invention, the first sleeve has a first opening, and the second sleeve has a second opening, the first opening and the second opening are aligned with each other, and the two ends of the elastic member respectively abut On both sides of the first opening and the second opening.

In an embodiment of the present invention, the above-mentioned link mechanism is a four-link mechanism.

In an embodiment of the present invention, the four-bar linkage mechanism includes a first link, a second link, a third link, and a fourth link. The first link is fixed to the body, the second link and the third link are respectively connected to two sides of the first link, and the fourth link is connected with the second link and the third link with respect to the first link Rod. When the four-bar linkage moves relative to the body, the four-bar linkage deforms.

In an embodiment of the present invention, the second link and the third link are rotated relative to the contact with the first link to drive the fourth link relative to the first link to move the four-bar linkage. Movement relative to the body.

In an embodiment of the present invention, the guiding chain piece is fixed to the fourth connecting rod, the torque limiting module is disposed at the joint of the first connecting rod and the second connecting rod, and the linking member is fixed to the second connecting rod. . When the transmission member and the linkage member move synchronously, the linkage member drives the second link to move relative to the contact point and drives the chain guide moving chain disposed on the fourth link.

In an embodiment of the present invention, the guide chain and the fourth link are integrally formed members, and the linkage is a second link.

In an embodiment of the present invention, the guiding chain piece is fixed to the fourth connecting rod, the torque limiting module is disposed at the joint of the first connecting rod and the third connecting rod, and the linking member is fixed to the third connecting rod. When the transmission member and the linkage member move synchronously, the linkage member drives the third link to rotate relative to the contact to drive the chain guide moving chain disposed on the fourth link.

In an embodiment of the present invention, the above-mentioned guide chain piece and the fourth link are integrally formed members, and the linkage member is a third link.

In an embodiment of the present invention, the elastic member is a torsion spring.

Based on the above, the present application proposes a transmission suitable for mounting to a bicycle. The transmission is provided with a torque limiting module between the transmission module and the linkage mechanism. When the transmission shaft of the transmission module is driven by the body to rotate, the transmission shaft drives the linkage mechanism to move relative to the body via the elastic member against the transmission member and the linkage member. When the drive shaft is driven by the body to rotate but the link mechanism cannot move, the transmission member moves relative to the linkage via the torsion elastic member, so that the transmission shaft does not drive the link mechanism. Accordingly, the transmission has a mechanism to prevent damage due to the chain and the pinion, so that the transmission does not damage the transmission module due to the chain being stuck.

In order to make the above features and advantages of the present invention more comprehensible, the following embodiments are described in detail with reference to the accompanying drawings.

1 is a schematic view of a transmission of an embodiment of the present invention applied to a bicycle. Figure 2 is a perspective view of the transmission of Figure 1. Referring to FIG. 1 and FIG. 2 , in the embodiment, the transmission 100 includes a transmission module 110 , a link mechanism 120 , a chain guide 130 , and a torque limiting module 140 . In the present embodiment, the transmission 100 can be a front derailleur adapted to be mounted to the frame 52 of the bicycle 50 to enable the bicycle 50 to switch the position of the chain 54 on the chainring 56.

Specifically, referring to FIG. 1 and FIG. 2 , in the embodiment, the transmission module 110 includes a body 112 and a transmission shaft 114 . The body 112 is adapted to be secured to the frame 52 of the bicycle 50 to secure the transmission 100. The drive shaft 114 is coupled to the body 112 and is driven to rotate by the body 112. Linkage mechanism 120 It is fixed to the transmission module 110 and is driven by the transmission shaft 114 to move relative to the body 112. The chain guide piece 130 is fixed to the link mechanism 120 and is driven by the link mechanism 120 to move the chain 54 of the bicycle 50.

In detail, the transmission 100 of the present embodiment is an electronic transmission. Therefore, the interior of the body 112 has an electric motor and a gear set (not shown), wherein the electric motor is coupled to the gear set, and the drive shaft 114 is fixed to one of the gears of the gear set. When the electric motor provides driving power and transmits via the gear set, the transmission shaft 114 rotates through the linkage of the respective gears in the gear set and drives the link mechanism 120 to move relative to the body 112, thereby causing the link mechanism 120 to drive the guide chain 130 moves.

In the present embodiment, the drive shaft 114 rotates along the axial direction X of the drive shaft 114 and drives the link mechanism 120 to move relative to the body 112 along the axial direction X. When the chain 54 and the toothed disc 56 are locked, the electric motor and the gear set drive transmission shaft 114 continue to rotate but the link mechanism 120 or the guide link 130 cannot move to cause damage to the transmission 100. Therefore, the torque limiting module 140 is disposed on the transmission module 110 and the link mechanism 120 to prevent the transmission 100 from being damaged when the chain 54 and the chainring 56 are locked to each other.

Figure 3 is a partial exploded view of the transmission of Figure 2. Referring to FIG. 2 and FIG. 3 , in the embodiment, the torque limiting module 140 includes a transmission member 142 , a linking member 144 , and an elastic member 146 . The transmission member 142 is fixed to the transmission shaft 114 and moves synchronously with the transmission shaft 114. The linkage 144 is coupled to the linkage 120. The elastic member 146 is disposed between the transmission member 142 and the linkage member 144.

In the present embodiment, the transmission member 142 is the first sleeve 142a, and the first sleeve 142a has the first opening 142b. The linkage 144 is a second sleeve 144a, and the second sleeve 144a has a second opening 144b. The elastic member 146 is a torsion spring, but the invention is not limited thereto. The second sleeve 144a is sleeved on the transmission shaft 114 connected to the body 112. The first sleeve 142a is sleeved on the second sleeve 144a and fixed to the transmission shaft 114, so that the first sleeve 142a and the second sleeve 144a A space is formed therebetween, and the elastic member 146 is sleeved on the transmission shaft 114 and housed in the space.

On the other hand, the elastic member 146 has a preload. When the elastic member 146 is sleeved on the transmission shaft 114 and received in the space, the two ends of the elastic member 146 abut against the transmission member 142 and the linkage member 144 respectively. In addition, when the first sleeve 142a is sleeved on the second sleeve 144a, the first opening 142b of the first sleeve 142a and the second opening 144b of the second sleeve 144a are aligned with each other. Therefore, the two ends of the elastic member 146 abut against the two sides of the first opening 142b and the second opening 144b, respectively, as shown in FIG. Accordingly, when the transmission member 142 and the linkage member 144 move synchronously, the transmission member 142 drives the linkage member 144 via the pre-compression, and when the transmission member 142 moves relative to the linkage member 144, the transmission member 142 twists the elastic member 146.

4 is a side elevational view of the transmission of FIG. 2. Referring to FIG. 2 and FIG. 4, in the embodiment, the link mechanism 120 is two sets of four-bar linkage mechanisms 120a and 120b, but the present invention does not limit the number of four-bar linkage mechanisms. The four link mechanisms 120a and 120b are respectively connected to both sides of the body 112 of the transmission module 110. In addition, the four-bar linkages 120a and 120b are interconnected such that the four-bar linkages 120a and 120b are synchronously movable relative to the body 112. In this embodiment, the manner in which the four-bar linkages 120a and 120b are fixed to the body 112 is compared with the operation mode of being driven by the transmission module 110. In the same manner, the four-bar linkage mechanism 120a will be described in detail, and the description of the four-bar linkage mechanism 120b can be referred to the four-bar linkage mechanism 120a.

Specifically, the four-bar linkage mechanism 120a includes a first link 122, a second link 124, a third link 126, and a fourth link 128. In this embodiment, the first link 122 is formed on one side of the body 112, and in other embodiments, the first link 122 may be a rod fixed to the body 112, which is not limited by this creation. . The second link 124 and the third link 126 are respectively connected to two sides of the first link 122, and the second link 124 and the third link 126 are respectively rotatable relative to the joint of the first link 122 . The fourth link 128 connects the second link 124 and the third link 126 with respect to the first link 122.

On the other hand, in the present embodiment, the transmission shaft 114 is located at the junction of the first link 122 and the second link 124, and the torque limiting module 140 is disposed at the first link 122 and the second link 124. The contact member, wherein the transmission member 142 of the torque limiting module 140 is fixed to the transmission shaft 114 and moves synchronously with the transmission shaft 114, and the linkage 144 of the torque limiting module 140 is fixed to the second link 124 and connected to the second connection. The rods 124 move in synchronism.

In addition, in the present embodiment, the chain guide piece 130 and the fourth link 128 are integrally formed members, that is, the fourth link 128 can be regarded as being constituted by a part of the chain guide piece 130. However, in other embodiments, the fourth link 128 may be a rod connecting the second link 124 and the third link 126, and the guide link 130 is fixed to the fourth link 128. For the limit. The guide link 130 is moved by the fourth link 128. When the transmission member 142 and the linkage member 144 move synchronously, the linkage member 144 drives the joint of the second link 124 relative to the first link 122.

Therefore, when the four-bar linkage 120a is driven by the transmission shaft 114, the four-bar linkage 120a moves relative to the body 112 and is deformed. The transmission shaft 114 drives the second link 124 to rotate relative to the pivot point of the transmission shaft 114 and the second link 124, and drives the fourth link 128 to move relative to the first link 122, thereby driving the chain guide 130 to move and moving the chain. 54.

In addition, the torque limiting module 140 of the present embodiment is disposed on the four-bar linkage 120a. In other embodiments, the torque limiting module 140 can be disposed on the four-bar linkage 120b or in the four-bar linkage 120a. The torque limiting module 140 is separately disposed on the 120b, and the present creation is not limited thereto.

Similarly, in other embodiments not shown, the transmission shaft 114 can be located at the junction of the first link 122 and the third link 126, and the torque limiting module 140 is disposed at the first link 122 and the third. The joint of the connecting rod 126, wherein the linking member 144 is fixed to the third connecting rod 126 to move synchronously with the third connecting rod 126. When the transmission member 142 and the linkage member 144 move synchronously, the linkage member 144 drives the contact of the third link 126 with respect to the first link 122, thereby driving the movement of the chain guide 130 disposed on the fourth link 128. .

In addition, in the embodiment where the torque limiting module is disposed at the junction of the first link and the second link, the linking member may be the second link, and the torque limiting module is disposed at the first link and the third In the embodiment of the joint of the connecting rod, the linking member may be a third connecting rod, and the present invention is not limited thereto.

5 is a side view of the drive shaft of FIG. 4 driving the link mechanism relative to the body, wherein a partial enlarged view on the right side of FIG. 5 shows the first sleeve 142a as a cross-sectional state, that is, a partially enlarged view is omitted. a top cover of the sleeve 142a to clearly show the elastic member 146 and the first sleeve 142a and the second sleeve The relative position between 144a. Referring to FIG. 5, in the embodiment, when the transmission shaft 114 is driven by the electric motor and the gear set inside the body 112 and rotates along the axial direction X to the first clock direction D1, the transmission shaft 114 is abutted via the elastic member 146. The transmission member 142 and the linking member 144 drive the link mechanism 120 to move relative to the body 112 along the axial direction X toward the first clock direction D1.

In detail, since the elastic member 146 having the preload is abutted against the transmission member 142 and the linkage member 144, the first opening 142b of the transmission member 142 and the second opening 144b of the linkage member 144 are aligned with each other, so that the elastic member 146 abuts at the same time. On both sides of the first opening 142b and the second opening 144b. In other words, the first end E31 of the elastic member 146 simultaneously abuts the first side E11 of the first opening 142b and the first side E21 of the second opening 144b, and the second end E32 of the elastic member 146 is simultaneously aligned against each other. The second side E12 of the first opening 142b and the second side E22 of the second opening 144b.

Therefore, when the transmission shaft 114 is driven by the body 112 to rotate in the first clock direction D1, the transmission member 142 moves synchronously with the transmission shaft 114 to rotate in the first clock direction D1, and the transmission member 142 abuts via the elastic member 146. The member 144 drives the linkage 144 to rotate synchronously and rotates in the first clock direction D1. At this time, both sides of the first opening 142b of the transmission member 142 push the two ends of the elastic member 146, and both ends of the elastic member 146 push the two sides of the linking member 144 to drive the linking member 144.

Therefore, when the transmission member 142 moves synchronously with the transmission shaft 114, the torque limiting module 140 can be regarded as a rigid body to cause the linkage member 144 to move synchronously with the transmission member 142. At this time, the second link 124 and the linkage 144 generate a synchronous motion, thereby causing the second link 124 to drive the fourth The link 128 moves synchronously to drive the chain guide 130, and its operation can be regarded as a state from the state of FIG. 4 to the state of FIG.

Similarly, when the drive shaft 114 is driven by the body 112 and rotates along the axial direction X to the second clock direction D2 opposite to the first clock direction D1, the drive shaft 114 drives the link mechanism 120 along the axial direction X. The two clock direction D2 moves relative to the body 112. At this time, the transmission member 142 moves synchronously with the transmission shaft 114 and abuts against the linkage 144 via the elastic member 146 to drive the linkage 144 to rotate synchronously to the second clock direction D2.

Therefore, the linking member 144 drives the second link 124 to rotate synchronously to the second clock direction D2, so that the second link 124 drives the fourth link 128 to move synchronously to drive the chain guide 130, and the operation process can be regarded as a figure. The state of 5 is converted to the state of Figure 4. Accordingly, the chain guide 130 can adjust the position of the chain 54 on the chainring 56 via the drive of the drive shaft 114.

Figure 6 is a side elevational view of the drive shaft of Figure 4 driving the transmission member relative to the linkage in a first clockwise direction, wherein a partial enlarged view of the right side of Figure 6 omits the top cover of the first sleeve 142a to show the torque limit The relative positions of the components of the module 140. Referring to FIG. 6, in the embodiment, when the electric motor inside the body 112 and the gear set drive transmission shaft 114 rotate but the link mechanism 120 cannot move, the transmission member 142 moves relative to the linkage member 144 via the torsion elastic member 146. The drive shaft 114 continues to operate without driving the linkage 120.

Specifically, when the electric motor and the gear set inside the body 112 drive the transmission shaft 114, the transmission shaft 114 rotates. At this time, if the link mechanism 120 cannot move, for example, the chain 54 of the bicycle 50 is caught on the toothed disc 56, When the chain guide 130 cannot move the chain 54 and the link mechanism 120 is prevented from moving, the rotating transmission shaft 114 rotates relative to the link mechanism 120 to generate torque.

This torque is transmitted to the electric motor and gear set inside the body 112 via the transmission shaft 114, which easily causes damage to the electric motor and the gear set. Therefore, the torque limiting module 140 can temporarily stop the interlocking relationship between the transmission shaft 114 and the link mechanism 120 in this case, so that the transmission shaft 114 continues to rotate but does not drive the linkage mechanism 120.

In detail, in the present embodiment, when the transmission shaft 114 is driven by the body 112 to rotate in the first clock direction D1, the transmission member 142 moves in synchronization with the transmission shaft 114. At this time, the first side E11 of the first opening 142b of the transmission member 142 pushes the first end E31 of the elastic member 146. At the same time, since the link mechanism 120 does not move, the linkage 144 cannot be rotated. Therefore, the second side E22 of the second opening 144b of the linkage 144 abuts against the second end E32 of the elastic member 146. Accordingly, the elastic member 146 is twisted along the axial direction X, thereby causing the transmission member 142 to move relative to the linkage member 144, and the operation thereof can be regarded as a state from the state of FIG. 4 to the state of FIG.

Figure 7 is a side elevational view of the drive shaft of Figure 4 driving the transmission member in a second clock direction relative to the linkage member, wherein a partial enlarged view of the right side of Figure 7 omits the top cover of the first sleeve 142a to show the torque limit The relative positions of the components of the module 140. Referring to FIG. 7, similarly, in the present embodiment, when the transmission shaft 114 is driven by the body 112 to rotate in the second clock direction D2, the transmission member 142 moves synchronously with the transmission shaft 114. At this time, the second side E12 of the first opening 142b of the transmission member 142 pushes the elastic member 146. Second end E32. At the same time, since the link mechanism 120 does not move, the linkage 144 cannot be rotated. Therefore, the first side E21 of the second opening 144b of the linkage 144 abuts against the first end E31 of the elastic member 146. Accordingly, the elastic member 146 generates a twist along the axial direction X, thereby causing the transmission member 142 to move relative to the linkage member 144, and the operation thereof can be regarded as a state from the state of FIG. 4 to the state of FIG.

Therefore, it can be seen that by providing the torque limiting module 140 between the transmission module 110 and the link mechanism 120, the transmission shaft 114 can be rotated by the driving of the body 112 but the linkage mechanism 120 cannot move relative to the linkage mechanism. The rotation of 120 continues to complete the predetermined action to prevent the drive shaft 114 from rotating relative to the link mechanism 120 to generate torque and thereby transmitted to the electric motor and gear set inside the body 112 to cause damage to the electric motor and the gear set.

Figure 8 is a partial exploded view of a transmission of another embodiment of the present invention. Figure 9 is a side elevational view of the transmission of Figure 8. Referring to FIG. 8 and FIG. 9, in the present embodiment, the main difference between the transmission 100a and the transmission 100 is that the transmission member 142 of the torque limiting module 140a of the transmission 100a has a stopping portion 142c. The stopper portion 142c is located at one side of the first opening 142b and abuts against the second opening 144b. The elastic member 146 simultaneously abuts both sides of the first opening 142b and the second opening 144b, and one end of the elastic member 146 is overlapped with the stopper portion 142c.

When the drive shaft 114 is driven by the body 112 to rotate along the axial direction X to the first clock direction D1 or the second clock direction D2, both ends of the elastic member 146 abut against both sides of the first opening 142b of the transmission member 142. The two sides of the second opening 144b of the linking member 144 are such that the torque limiting module 140 can be regarded as a rigid body. At this time, the linking member 144 and the transmission member 142 can be synchronized. motion. Therefore, the transmission shaft 114 drives the link mechanism 120 to rotate in the first clock direction D1 or the second clock direction D2 to drive the chain guide 130. For the operation process, reference may be made to the operation of the transmission 100 shown in FIG.

10 is a side view of the drive shaft driving transmission member of FIG. 9 moving relative to the linking member in the second clock direction, wherein a partial enlarged view on the right side of FIG. 10 omits the top cover of the first sleeve 142a to show the torque limit. The relative position of each component of module 140a. Referring to FIG. 10, in the present embodiment, when the transmission shaft 114 is driven by the body 112 to rotate in the second clock direction D2, the transmission member 142 moves synchronously with the transmission shaft 114. At this time, the second side E12 of the transmission member 142 pushes the second end E32 of the elastic member 146. At the same time, since the link mechanism 120 does not move, the linkage 144 cannot be rotated. Therefore, the first side E21 of the linkage 144 abuts against the first end E31 of the elastic member 146. Accordingly, the elastic member 146 is twisted along the axial direction X, thereby causing the transmission member 142 to move relative to the linkage member 144, and the operation thereof can be regarded as a state from the state of FIG. 9 to the state of FIG.

In addition, when the transmission shaft 114 rotates in the second clock direction D2, the stopping portion 142c located on the second side E12 of the first opening 142b does not affect the movement of the transmission member 142 relative to the linking member 144 as the transmission member 142 rotates synchronously. . On the contrary, when the driving shaft 114 rotates in the first clock direction D1, the stopping portion 142c located on the second side E12 of the first opening 142b abuts against the linking member 144 to prevent the transmission member 142 from moving toward the first clock relative to the linking member 144. Direction D1 movement. In addition, the stopping portion 142c may also be disposed on the first side E11 of the first opening 142b of the transmission member 142, which is not limited thereto.

Accordingly, the torque limiting module 140a is disposed on the transmission member 142. The stop portion 142c provides the transmission 100a to twist the resilient member 146 in a single direction such that the transmission 100a continues to rotate relative to the linkage 120 when the drive shaft 114 is rotated by the drive of the body 112 but the linkage 120 is inoperable. The predetermined action is completed to prevent the drive shaft 114 from rotating relative to the link mechanism 120 to generate torque and thereby transmit to the electric motor and gear set inside the body 112 to cause damage to the electric motor and the gear set.

In summary, the present application proposes a transmission suitable for mounting to a bicycle. The transmission is provided with a torque limiting module between the transmission module and the linkage mechanism. When the transmission shaft of the transmission module is driven by the body to rotate, the transmission shaft abuts the transmission member and the linkage member via the elastic member to synchronously move the transmission member and the linkage member to drive the linkage mechanism to move relative to the body. When the drive shaft is driven by the body to rotate but the link mechanism cannot move, the transmission member moves relative to the linkage via the torsion elastic member so that the drive shaft does not drive the link mechanism. Accordingly, the transmission has a mechanism to prevent damage due to the chain and the pinion, so that the transmission does not damage the transmission module due to the chain being stuck.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any person having ordinary knowledge in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of protection of this creation is subject to the definition of the scope of the patent application attached.

50‧‧‧Bicycle

52‧‧‧ frame

54‧‧‧Chain

56‧‧‧ toothed disc

100, 100a‧‧‧Transmission

110‧‧‧Drive Module

112‧‧‧Ontology

114‧‧‧Drive shaft

120‧‧‧ linkage mechanism

120a, 120b‧‧‧ four-bar linkage

122‧‧‧First connecting rod

124‧‧‧Second connecting rod

126‧‧‧third link

128‧‧‧fourth link

130‧‧‧ Guide chain

140, 140a‧‧‧Torque Limit Module

142‧‧‧ Transmission parts

142a‧‧‧first sleeve

142b‧‧‧ first opening

142c‧‧‧stop

144‧‧‧ linkages

144a‧‧‧Second sleeve

144b‧‧‧second opening

146‧‧‧Flexible parts

D1‧‧‧First clock direction

D2‧‧‧second clock direction

E11, E21‧‧‧ first side

E12, E22‧‧‧ second side

E31‧‧‧ first end

E32‧‧‧ second end

X‧‧‧ axial

1 is a schematic view of a transmission of an embodiment of the present invention applied to a bicycle.

Figure 2 is a perspective view of the transmission of Figure 1.

Figure 3 is a partial exploded view of the transmission of Figure 2.

4 is a side elevational view of the transmission of FIG. 2.

Figure 5 is a side elevational view of the drive shaft of Figure 4 driving the linkage mechanism relative to the body.

Figure 6 is a side elevational view of the drive shaft of Figure 4 driving the transmission member relative to the linkage in a first clockwise direction.

Figure 7 is a side elevational view of the drive shaft of Figure 4 driving the transmission member in a second clockwise direction relative to the linkage.

Figure 8 is a partial exploded view of a transmission of another embodiment of the present invention.

Figure 9 is a side elevational view of the transmission of Figure 8.

Figure 10 is a side elevational view of the drive shaft of Figure 9 driving the transmission member in a second clock direction relative to the linkage.

100‧‧‧Transmission

110‧‧‧Drive Module

112‧‧‧Ontology

114‧‧‧Drive shaft

120‧‧‧ linkage mechanism

120a, 120b‧‧‧ four-bar linkage

130‧‧‧ Guide chain

140‧‧‧Torque limit module

142‧‧‧ Transmission parts

142a‧‧‧first sleeve

142b‧‧‧ first opening

144‧‧‧ linkages

144a‧‧‧Second sleeve

144b‧‧‧second opening

146‧‧‧Flexible parts

X‧‧‧ axial

Claims (14)

A transmission adapted to be mounted to a bicycle, the transmission comprising: a transmission module comprising a body and a transmission shaft, the body being adapted to be fixed to a frame of the bicycle, the transmission shaft being coupled to the body and receiving The main body is driven to rotate; a link mechanism fixed to the transmission module and driven by the transmission shaft to move relative to the main body; a guide chain fixed to the link mechanism and received by the connecting rod a chain that is adapted to move the bicycle; and a torque limiting module, comprising: a transmission member fixed to the transmission shaft and synchronously moving with the transmission shaft; a linkage member coupled to the linkage mechanism And an elastic member disposed between the transmission member and the linkage member, and the transmission shaft abuts the transmission member via the elastic member when the transmission shaft is driven by the body to rotate along an axial direction The linkage moves the linkage mechanism relative to the body, and when the transmission shaft is driven by the body to rotate along the axial direction but the linkage mechanism is incapable of moving, the transmission member is twisted along the axial direction. bomb Member relative to the motion of the interlocking member. The transmission of claim 1, wherein the drive shaft drives the link mechanism to move relative to the body along the axial direction as the drive shaft rotates along the axial direction. The transmission of claim 2, wherein the transmission When the moving shaft rotates along the axial direction in a first clock direction, the link mechanism moves relative to the body along the axial direction toward the first clock direction, and when the transmission shaft is opposite to the first clock along the axial direction When the second clock direction of the direction is rotated, the link mechanism moves relative to the body along the axial direction toward the second clock direction. The transmission of claim 1, wherein the elastic member has a preload so that both ends of the elastic member abut against the transmission member and the linkage member, respectively, when the transmission member is synchronized with the linkage member During the movement, the transmission member drives the linkage through the pre-compression, and the transmission member twists the elastic member when the transmission member moves relative to the linkage member. The transmission of claim 1, wherein the transmission member is a first sleeve, the linkage member is a second sleeve, and the second sleeve and the elastic member are respectively sleeved on the transmission shaft. The first sleeve is fixed to the transmission shaft and sleeved on the second sleeve to form a space to accommodate the elastic member. The transmission of claim 5, wherein the first sleeve has a first opening, the second sleeve has a second opening, the first opening and the second opening are aligned with each other, and the elasticity The two ends of the piece respectively abut against the first opening and the two sides of the second opening. The transmission of claim 1, wherein the link mechanism is a four-bar linkage mechanism. The transmission of claim 7, wherein the four-bar linkage includes a first link, a second link, a third link, and a fourth link, the first link is fixed The second link and the third link are respectively connected to two sides of the first link, and the fourth link is connected to the second link and the first link with respect to the first link Three links, when the four The four-bar linkage is deformed when the lever mechanism moves relative to the body. The transmission of claim 8, wherein the second link and the third link rotate relative to the contact with the first link to drive the fourth link relative to the first link Movement causes the four-bar linkage to move relative to the body. The transmission of claim 8, wherein the chain guide is fixed to the fourth link, and the torque limiting module is disposed at a joint of the first link and the second link, and the linkage The member is fixed to the second link, and when the transmission member moves synchronously with the linkage member, the linkage member drives the second link to move relative to the contact point and drive the guide chain disposed on the fourth link The piece moves the chain. The transmission of claim 10, wherein the chain guide and the fourth link are integrally formed members, and the linkage member is the second link. The transmission of claim 8, wherein the chain guide is fixed to the fourth link, and the torque limiting module is disposed at a joint of the first link and the third link, and the linkage The member is fixed to the third link, and when the transmission member moves synchronously with the linkage member, the linkage member drives the third link to rotate relative to the contact to drive the guide chain disposed on the fourth link The piece moves the chain. The transmission of claim 12, wherein the chain guide and the fourth link are integrally formed members, and the linkage member is the third link. The transmission of claim 1, wherein the elastic member is a torsion spring.