Key connection transmission structure and electric bicycle

Abstract

The utility model relates to a key connection transmission structure and an electric bicycle, the key connection transmission structure comprises a driving shaft and a transmission piece matched with the spline of the driving shaft, the outer wall of the driving shaft is circumferentially provided with an outer spline, the inner wall of the transmission piece is circumferentially provided with an inner spline, one end of the driving shaft is an installation end allowing the transmission piece to be sleeved in, and the other end of the driving shaft is an installation end allowing the transmission piece to be sleeved in. The driving shaft is provided with an axial limiting structure, the axial limiting structure abuts against the side, away from the installation end, of the transmission part after the transmission part is installed in place, the installation end of the driving shaft is provided with a limiting part for axially limiting the side, close to the installation end, of the transmission part, and axial limiting of the two ends of the transmission part can be achieved. In addition, radial limiting structures are further arranged at the positions, close to the axial limiting structures, of the transmission part and the driving shaft, radial limiting of the transmission part is achieved, the transmission part can stably conduct transmission even under the condition that the manufacturing precision is not high, and the problem that the transmission part shakes is avoided.

Description

Technical Field

[0001] The utility model relates to the technical field of transmission systems, in particular to a key-connected transmission structure and an electric bicycle. Background Art

[0002] The key connection transmission structure is a common torque transmission structure in the mechanical field. Taking an electric vehicle as an example, a drive shaft is provided on the motor side cover connecting seat of the electric vehicle, and the drive shaft is connected to the flywheel. In the prior art, the flywheel and the drive shaft are used for power transmission through spline matching, and the flywheel is circumferentially positioned by spline matching. However, in order to reduce costs, the processing accuracy of the external splines on the drive shaft and the internal splines on the flywheel is relatively low. The radial and axial shaking of the internal splines and the external splines is prone to occur only through the matching of the internal splines and the external splines. In the prior art, the axial freedom of the inner splines of the flywheel is limited only by the retaining spring, but the problem of radial shaking of the flywheel still occurs, which aggravates the wear of the inner and outer splines.

[0003] Therefore, it is a technical problem that technicians in this field need to solve urgently to limit the radial freedom of the key-connected torque transmission structure and avoid wear of the internal and external splines due to low machining precision. Utility Model Content

[0004] In order to solve the above problems, the utility model provides a key-connected transmission structure on one hand, which can limit the radial freedom of the key-connected torque transmission structure and avoid wear of the internal and external splines.

[0005] To achieve the above purpose, the utility model provides the following solutions:

[0006] A key-connected transmission structure comprises: a driving shaft, and a transmission member that cooperates with the driving shaft spline, the outer wall of the driving shaft is circumferentially provided with external splines, and the inner wall of the transmission member is circumferentially provided with internal splines, and is characterized in that one end of the driving shaft is a mounting end that allows the transmission member to be inserted, and an axial limiting structure is provided on the driving shaft, and the axial limiting structure abuts against a side of the transmission member away from the mounting end after the transmission member is installed in place, and the mounting end of the driving shaft is provided with a limiting member for axially limiting the side of the transmission member close to the mounting end, and a radial limiting structure is also provided at the position of the transmission member and the driving shaft close to the axial limiting structure.

[0007] Preferably, the radial limiting structure includes a positioning step and a positioning stop matched with the positioning step, one of the positioning step and the positioning stop is arranged on the end face of the axial limiting structure and is arranged circumferentially along the outer wall of the drive shaft, and the other of the positioning step and the positioning stop is arranged circumferentially along the inner wall of the transmission member.

[0008] Preferably, an elastic component capable of providing an axial pre-tightening force for the transmission member is also provided in the positioning stop.

[0009] Preferably, the radial limiting structure includes a plurality of positioning circular holes and a plurality of positioning bosses matched with the positioning circular holes, one of the plurality of positioning circular holes and the plurality of positioning bosses is arranged on the end face of the axial limiting structure abutting against the transmission member, and is arranged at intervals along the circumference of the drive shaft, and the other of the plurality of positioning circular holes and the plurality of positioning bosses is arranged on the end face of the transmission member used to abut against the axial limiting structure, and is arranged at intervals along the circumference of the transmission member.

[0010] Preferably, the external splines and the internal splines are involute splines, rectangular splines or triangular splines.

[0011] Preferably, the axial limiting structure is a shoulder arranged on the driving shaft, and an elastic component is arranged between the end surface of the shoulder and the transmission member.

[0012] Preferably, the elastic member is an O-ring or a wave washer.

[0013] Preferably, a limiting groove for accommodating the limiting member is circumferentially arranged on the outer wall of the driving shaft close to the mounting end.

[0014] Preferably, the limiting member is a retaining spring or a spring retaining ring.

[0015] On the other hand, the utility model also discloses an electric bicycle, comprising a flywheel and a hub shaft transmission connected to the flywheel, wherein the connection structure between the flywheel and the hub shaft is a key connection transmission structure as described in any one of the above items.

[0016] After the transmission part is assembled in place, the transmission part and the axial limiting structure arranged on the drive shaft are abutted against each other to achieve axial limiting on the side away from the mounting end. After the radial limiting structure arranged on the transmission part and the drive shaft cooperate, radial limiting of the transmission part can be achieved. Even if the manufacturing precision of the splines on the transmission part and the drive shaft is low, radial shaking of the transmission part will not occur due to the setting of the radial limiting structure. Finally, the setting of the limiting part achieves abutment against the side of the transmission part close to the mounting end, and axial limiting of the transmission part close to the mounting end can be performed.

[0017] It can be seen that the utility model has achieved the following technical effects compared with the prior art:

[0018] By setting an axial limiting structure away from the mounting end and a limiting member close to the mounting end, axial limiting of both ends of the transmission member can be achieved, and by setting a radial limiting structure on or near the axial limiting structure, radial limiting of the transmission member can be achieved, so that the transmission member can be transmitted smoothly even when the manufacturing precision is not high, thus avoiding the problem of radial shaking of the transmission member, reducing the wear of the transmission member caused by shaking, and improving the service life of the key-connected transmission structure.

[0019] Since the electric bicycle disclosed in the utility model adopts the above-mentioned key connection transmission structure, the electric bicycle has the corresponding technical advantages of the above-mentioned key connection transmission structure, which will not be described in detail in this application document. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the drawings required for use in the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0021] Attached Figure 1 It is a schematic diagram of the overall structure of the key-connected transmission structure disclosed in the utility model;

[0022] Attached Figure 2 for Figure 1 Schematic diagram of the exploded view of the key-connected transmission structure;

[0023] Attached Figure 3 This is a schematic diagram of the assembly of the key-connected transmission structure disclosed in the utility model;

[0024] Attached Figure 4 It is a schematic diagram of the driving shaft of the key-connected transmission structure disclosed in the utility model;

[0025] Attached Figure 5 It is a cross-sectional schematic diagram of a transmission member of a key-connected transmission structure disclosed in the utility model;

[0026] Among them, 1. driving shaft; 2. transmission part; 3. limiting part; 4. elastic member; 5. internal spline; 6. external spline; 7. positioning stop; 8. positioning step; 9. limiting groove; 10. shaft shoulder. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] One of the purposes of the utility model is to provide a key-connected transmission structure, which can not only position the axial direction of the torque transmission structure, but also limit the radial freedom of the key-connected torque transmission structure to avoid wear of the internal and external splines.

[0029] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0030] refer to Figure 2 and Figure 3 The key-connected transmission structure disclosed in the embodiment of the utility model at least includes a driving shaft 1, a transmission member 2, an axial limiting structure, a radial limiting structure and a limiting member 3. The outer wall of the driving shaft 1 is circumferentially provided with an external spline 6, and the inner wall of the transmission member 2 is circumferentially provided with an internal spline 5. The driving shaft 1 and the transmission member 2 are connected by splines. The end of the driving shaft 1 that allows the transmission member 2 to be inserted is the mounting end. The side of the driving shaft 1 away from the mounting end is provided with an axial limiting structure. When the driving shaft 1 and the transmission member 2 are connected by spline matching, the side of the transmission member 2 away from the mounting end abuts against the axial limiting structure to achieve axial limitation of the transmission member 2. A radial limiting structure is provided on the side of the driving shaft 1 close to the mounting end. A limiting member 3 is provided. When one end of the transmission member 2 abuts against the axial limiting structure of the drive shaft 1, the limiting member 3 is set at the installation end of the drive shaft 1, and the other end of the transmission member 2 abuts against the limiting member 3 to ensure the axial limitation of both ends of the transmission member 2. A radial limiting structure is provided at the position of the transmission member 2 and the drive shaft 1 close to the axial limiting structure. After the drive shaft 1 and the transmission member 2 are connected by spline cooperation, the radial direction of the transmission member 2 is limited by the radial limiting structure. Even if the manufacturing precision of the splines on the drive shaft 1 and the transmission member 2 is low, the radial limiting structure can effectively limit the transmission member 2 radially, thereby avoiding the problem of radial shaking of the transmission member 2 causing wear of the internal and external splines.

[0031] The assembly process of the key-connected transmission structure disclosed in the above embodiment is as follows:

[0032] When realizing the spline connection between the drive shaft 1 and the transmission member 2, the transmission member 2 is inserted from the mounting end of the drive shaft 1 and cooperates with the drive shaft 1 through the spline, so that the side of the transmission member 2 away from the mounting end abuts against the axial limiting structure, and the radial limiting structure arranged on the transmission member 2 and the drive shaft 1 cooperates to realize radial limitation of the transmission member 2, and the side of the transmission member 2 close to the mounting end abuts against the limiting member 3, thereby realizing the purpose of axial limitation of both ends of the transmission member 2 and radial limitation at the same time.

[0033] It can be seen that the key-connected transmission structure disclosed in the above embodiment realizes the limitation of radial freedom of the key-connected torque transmission structure, thereby avoiding wear of the internal and external splines.

[0034] refer to Figure 3-5 In one embodiment, the radial limiting structure includes a positioning step 8 and a positioning stop 7 matched with the positioning step 8. The positioning step 8 is arranged on the end face of the axial limiting structure, and the positioning step 8 is arranged along the circumference of the outer wall of the driving shaft 1. The positioning stop 7 is arranged on the circumference of the inner wall of the transmission member 2. When the transmission member 2 abuts against the axial limiting structure, the positioning step 8 cooperates with the positioning stop 7 to realize the radial limiting of the transmission member 2.

[0035] Alternatively, a positioning stop 7 is provided on the end face of the axial limiting structure, and the positioning stop 7 is provided along the circumference of the outer wall of the driving shaft 1, and a positioning step 8 is provided on the circumference of the inner wall of the transmission member 2. When the transmission member 2 abuts against the axial limiting structure, the positioning step 8 and the positioning stop 7 cooperate to realize radial limitation of the transmission member 2.

[0036] refer to Figure 3 As a preferred method, an elastic component 4 capable of providing axial preload for the transmission member 2 is also provided in the positioning stop 7. When the transmission member 2 is installed in place, the positioning stop 7 cooperates with the positioning step 8 to squeeze the elastic component 4 so that the elastic component 4 provides axial preload for the transmission member 2.

[0037] As another optional method, the radial limiting structure includes a plurality of positioning circular holes and a plurality of positioning protrusions adapted to the positioning circular holes. A plurality of positioning circular holes are arranged at intervals along the circumference of the drive shaft 1 on the end face of the axial limiting structure abutting against the transmission member 2, and a plurality of positioning protrusions are arranged at intervals along the circumference of the transmission member 2 on the end face of the transmission member 2 used to abut against the axial limiting structure. When the transmission member 2 abuts against the axial limiting structure, the plurality of positioning circular holes cooperate with the plurality of positioning protrusions to achieve radial limiting of the transmission member 2.

[0038] Alternatively, a plurality of positioning bosses are arranged at intervals along the circumference of the drive shaft 1 on the end face where the axial limiting structure abuts against the transmission member 2, and a plurality of positioning circular holes are arranged at intervals along the circumference of the transmission member 2 on the end face where the transmission member 2 abuts against the axial limiting structure. When the transmission member 2 abuts against the axial limiting structure, the plurality of positioning circular holes cooperate with the plurality of positioning bosses to realize radial limitation of the transmission member 2.

[0039] refer to Figure 2 As a preferred embodiment, the external spline 6 and the internal spline 5 are one of an involute spline, a rectangular spline or a triangular spline.

[0040] refer to Figures 1 to 3 In the embodiment of the utility model, the axial limiting structure is a shoulder 10 arranged on the drive shaft 1, and the end face of the shoulder 10 is used to abut against the transmission member 2 to achieve the limitation of the transmission member 2. When the transmission member 2 is installed in place, the end face of the shoulder 10 abuts against the transmission member 2, and the elastic member 4 is under pressure at this time. Through the squeezing of the elastic member 4 by the transmission member 2, the elastic member 4 applies an axial preload to the transmission member 2.

[0041] It should be noted that the axial limiting structure in the utility model can be used in conjunction with any of the radial limiting structures described above; when the radial limiting structure is a positioning circular hole and a positioning boss, in order to provide axial preload force to the transmission member 2, an elastic member 4 can be arranged between the transmission member and the end face of the axial positioning structure.

[0042] Those skilled in the art can understand that the role of the elastic component is to provide axial preload for the transmission part. Therefore, any elastic component that can play the above role can be applied to the present solution. Considering the cost savings and production convenience, the elastic component 4 in the embodiment of the utility model is an O-ring or a corrugated washer.

[0043] refer to Figure 4 As a preferred method, a limiting groove 9 for accommodating the limiting member 3 is circumferentially arranged on the outer wall of the driving shaft 1 near the mounting end. The limiting groove 9 is provided to limit the limiting member 3, so that the limiting member 3 can better provide axial limitation for the transmission member 2.

[0044] refer to Figure 2 As a preferred embodiment, the limiting member 3 is a retaining spring or a spring retaining ring. Of course, other limiting members including bolts can also be used to achieve axial limiting of the transmission member 2.

[0045] The utility model also discloses an electric bicycle in an embodiment, which includes a flywheel and a hub shaft. The connection structure between the flywheel and the hub shaft is a key connection transmission structure in any one of the above items. It is well known to those skilled in the art that in full electric drive, no human power output is required, so the flywheel does not provide power to the entire vehicle. In some power-assisted electric vehicles that require human assistance for power, the chain transmits the torque output by human power to the hub shaft through the flywheel to assist the electric vehicle to move; or when the electric vehicle is in a power-deficient or power-free state and requires human power drive, the chain transmits the torque output by human power to the hub shaft through the flywheel to drive the electric vehicle to move. As a preferred method, a key connection transmission structure is used between the flywheel and the hub, and the key connection transmission structure is the key connection transmission structure disclosed in any one of the above embodiments.

[0046] By attaching Figure 2 and attached Figure 3 It can be seen that when this type of key-connected transmission structure is applied in the field of electric bicycles, only very small modifications are required to achieve radial limitation of the flywheel. Specifically, a positioning step 8 is directly processed on the original shoulder end face, and the radial positioning can be achieved by utilizing the groove (i.e., the positioning stop 7) originally used to place the elastic component 4. One groove can be used for multiple purposes. The positioning stop 7 can be used as both a groove for placing the elastic component 4 and a positioning stop 7 for radial limitation. This design hardly increases the cost and reduces the material usage. It can be done with minimal modifications on the basis of the original structure of the drive shaft 1 and the transmission component 2, which can not only achieve radial limitation but also reduce costs.

[0047] Adaptive changes made according to actual needs are all within the protection scope of this utility model.

[0048] It should be noted that it is obvious to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any reference numerals in the claims should not be regarded as limiting the claims involved.

Claims

1. A key connection transmission structure, comprising: A driving shaft, and a transmission member that cooperates with the driving shaft spline, the outer wall of the driving shaft is circumferentially provided with external splines, and the inner wall of the transmission member is circumferentially provided with internal splines, characterized in that one end of the driving shaft is a mounting end that allows the transmission member to be inserted, and an axial limiting structure is provided on the driving shaft, and the axial limiting structure abuts against the side of the transmission member away from the mounting end after the transmission member is installed in place, and the mounting end of the driving shaft is provided with a limiting member for axially limiting the side of the transmission member close to the mounting end, and a radial limiting structure is also provided at the position of the transmission member and the driving shaft close to the axial limiting structure.

2. The key connection transmission structure according to claim 1, characterized in that: The radial limiting structure includes a positioning step and a positioning stop matched with the positioning step, one of the positioning step and the positioning stop is arranged on the end face of the axial limiting structure and is arranged circumferentially along the outer wall of the drive shaft, and the other of the positioning step and the positioning stop is arranged circumferentially along the inner wall of the transmission member.

3. The key connection transmission structure according to claim 2, characterized in that: An elastic component capable of providing an axial pre-tightening force for the transmission member is also arranged in the positioning stop.

4. The key connection transmission structure according to claim 1, characterized in that: The radial limiting structure includes a plurality of positioning circular holes and a plurality of positioning bosses matched with the positioning circular holes, one of the plurality of positioning circular holes and the plurality of positioning bosses is arranged on the end surface of the axial limiting structure abutting against the transmission member, and is arranged at intervals along the circumference of the drive shaft, and the other of the plurality of positioning circular holes and the plurality of positioning bosses is arranged on the end surface of the transmission member used to abut against the axial limiting structure, and is arranged at intervals along the circumference of the transmission member.

5. The key connection transmission structure according to claim 1, characterized in that: The external splines and the internal splines are involute splines, rectangular splines or triangular splines.

6. The key connection transmission structure according to claim 1, characterized in that: The axial limiting structure is a shaft shoulder arranged on the driving shaft.

7. The key connection transmission structure according to claim 3, characterized in that: The elastic component is an O-ring or a wave washer.

8. The key connection transmission structure according to claim 1, characterized in that: The outer wall of the driving shaft close to the mounting end is circumferentially provided with a limiting groove for accommodating the limiting member.

9. The key connection transmission structure according to any one of claims 1 to 6 and 8, characterized in that: The limiting member is a retaining spring or a spring retaining ring.

10. An electric bicycle, comprising a flywheel and a hub shaft drivingly connected to the flywheel, characterized in that: The connection structure between the flywheel and the hub shaft is a key connection transmission structure as described in any one of claims 1-9.

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