A clutch type electric bicycle sprocket drive mechanism

Abstract

The present invention discloses a clutch type electric bicycle sprocket drive mechanism, comprising a wheel axle, a motor end plate, a sprocket, an outer end plate and a reset spring, wherein the outer end plate, the sprocket and the motor end plate are sequentially mounted on the wheel axle from outside to inside; the outer end surface of the motor end plate is provided with a circle of teeth; the sprocket and the wheel axle are rotatably mounted, and there is a clearance sliding fit between the sprocket and the wheel axle, and the sprocket can slide along the axial direction of the wheel axle; a locking column matched with the teeth of the motor end plate is provided on the side of the sprocket opposite to the motor end plate; a ratchet pawl mechanism for driving the sprocket to approach the motor end plate is provided between the sprocket and the outer end plate; the reset spring is installed between the sprocket and the motor end plate, and provides a restoring force for the sprocket to separate from the motor end plate. The sprocket will mesh with the motor wheel for transmission only when in a riding state, thereby greatly reducing the working time of the sprocket and extending the service life of the sprocket; and reducing the running noise of the sprocket, avoiding the occurrence of heel rotation.

Description

Technical Field

[0001] The invention belongs to the technical field of electric bicycles, and in particular relates to a clutch type electric bicycle sprocket drive mechanism. Background Art

[0002] See attached Figure 6 and 7 The existing bicycle rear wheel drive structure is that the motor wheel is installed on the rear wheel shaft a, and the motor end plate b of the motor wheel is provided with a threaded opening b-1 for installing the flywheel (i.e., sprocket), and the flywheel c is installed on the threaded opening through a thread to achieve fixed installation with the motor wheel, and there is a circle of teeth on the outer ring of the flywheel, so that the outer ring of the flywheel is linked to the crank wheel plate through a chain to achieve chain transmission, and the inside of the flywheel adopts a ratchet pawl structure to ensure one-way transmission of riding. This flywheel transmission structure has the following problems:

[0003] 1. The flywheel always runs with the motor wheel, which greatly increases the working time of the flywheel. Since the flywheel has a ratchet and pawl structure to ensure one-way transmission during riding, the ratchet and pawl structure inside the flywheel is easily damaged, resulting in a shorter service life of the flywheel.

[0004] 2. After the flywheel has worked for a long time and aged, the crank is prone to follow-rotation (when the motor wheel is running, the friction inside the flywheel increases due to aging, which may drive the outer ring of the flywheel to rotate, and then the outer ring of the flywheel drives the chain to rotate, and the chain drives the crank to follow the rotation). The crank will cause the vehicle power-assist sensor to send a power-assist signal to the controller. The controller mistakenly thinks that the customer is using the power-assist function, causing the vehicle to run away, posing a hidden danger to the customer's travel safety.

[0005] 3. After the flywheel has been working for a long time and aged, a loud noise will occur when the motor wheel drives the flywheel to operate.

[0006] 4. The flywheel is installed on the motor end plate through threads. The flywheel is prone to thread removal when running for a long time, thus causing safety hazards. Summary of the invention

[0007] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a clutch type electric bicycle sprocket drive mechanism.

[0008] The present invention is achieved through the following technical solutions:

[0009] A clutch type electric bicycle sprocket drive mechanism comprises a wheel shaft, a motor end plate, a sprocket, an outer end plate and a return spring, wherein the outer end plate, the sprocket and the motor end plate are sequentially mounted on the wheel shaft from outside to inside;

[0010] The outer end surface of the motor end plate is provided with a circle of teeth;

[0011] The sprocket is rotatably mounted on the axle, and there is a clearance sliding fit between the sprocket and the axle, so that the sprocket can slide axially along the axle; a locking column matching the teeth of the motor end disc is arranged on the side of the sprocket opposite to the motor end disc;

[0012] A ratchet and pawl mechanism is arranged between the sprocket and the outer end disc. When the sprocket rotates in the forward direction, the ratchet and pawl mechanism drives the sprocket to approach the motor end disc, thereby realizing the transmission engagement between the sprocket and the motor end disc.

[0013] The return spring is installed between the sprocket and the motor end disc to provide a restoring force for the sprocket to separate from the motor end disc.

[0014] In the above technical solution, the outer end disc is fixedly mounted on the wheel axle by means of threads.

[0015] In the above technical solution, a pawl is arranged on the inner surface of the outer end disc, and a circle of ratchet teeth is arranged on the outer end surface of the sprocket.

[0016] In the above technical solution, the top action surface of the pawl and the tooth surface of the ratchet are mutually matching inclined surfaces.

[0017] In the above technical solution, the tooth spacing between the teeth on the motor end disk is larger than the diameter of the locking column, so that the locking column can smoothly enter between the teeth, and each tooth on the motor end disk is inclined. In this way, when the locking column just enters between the teeth, as the sprocket rotates, even if the sprocket loses the driving action of the ratchet and pawl mechanism, the locking column can continue to enter the root of the tooth under the guiding action of the tooth's own inclination.

[0018] In the above technical solution, the number of locking columns on the sprocket is not limited to one, and may be multiple.

[0019] In the above technical solution, the specific structure of the sprocket is as follows: it includes a cylinder body, a circle of retaining walls is arranged on the inner wall of the cylinder body, a bearing is arranged in the outer cylinder cavity of the retaining wall, and is installed on the wheel axle through the bearing, and there is a clearance fit between the bearing and the wheel axle, and can slide axially along the wheel axle; the inner cylinder cavity of the retaining wall is used to install the reset spring; a circle of chain teeth is arranged on the outer wall of the cylinder body, for installing the chain; a ratchet is processed on the outer end of the cylinder body, and the locking column is arranged on the outer wall of the inner end of the cylinder body.

[0020] In the above technical solution, a mounting groove for mounting the pawl is provided on the inner surface of the outer end disc, and the pawl is mounted in the mounting groove via a torsion spring.

[0021] In the above technical solution, a protective cover is arranged on the outer end disc, and the protective cover covers the ratchet teeth and pawls to play a role in dust protection.

[0022] The advantages and beneficial effects of the present invention are:

[0023] 1. The sprocket of the present invention does not have the risk of wire withdrawal and separation.

[0024] 2. The sprocket of the present invention will mesh with the motor wheel for transmission only when the vehicle is riding, thereby greatly reducing the working time of the sprocket and extending the service life of the sprocket; and reducing the operating noise of the sprocket and avoiding the occurrence of heel rotation.

[0025] 3. The sprocket of the present invention has no ratchet and pawl mechanism inside, thereby increasing the working stability and service life of the sprocket.

[0026] 4. The sprocket of the present invention is directly mounted on the wheel axle. Compared with the traditional sprocket mounted on the threaded opening of the motor end plate, its inner diameter is smaller. Therefore, it is beneficial to reduce the size of the sprocket and make the vehicle design more beautiful. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a three-dimensional structural schematic diagram of the sprocket drive mechanism of the clutch type electric bicycle of the present invention.

[0028] Figure 2 It is a cross-sectional view of the clutch type electric bicycle sprocket drive mechanism of the present invention.

[0029] Figure 3 It is a partial enlarged view of the ratchet pawl in the present invention.

[0030] Figure 4 It is a schematic diagram of a protective cover provided on the outer end plate of the present invention.

[0031] Figure 5 It is a schematic diagram of the structure between the sprocket and the outer end disc in the present invention when the pawl and ratchet restraint state is lost.

[0032] Figure 6 It is a schematic diagram of the structure of an existing bicycle motor wheel in the background technology.

[0033] Figure 7 It is a schematic diagram of the existing bicycle motor wheel and flywheel installation structure in the background technology.

[0034] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below in conjunction with specific embodiments.

[0036] Embodiment 1

[0037] See attached Figure 1-2A clutch type electric bicycle sprocket drive mechanism comprises a wheel shaft 1, a motor end plate 2, a sprocket 3, an outer end plate 4 and a return spring 5.

[0038] The motor end plate 2 is rotatably mounted on the wheel shaft 1, and a circle of teeth 2-1 is arranged on the outer end surface of the motor end plate.

[0039] The sprocket 3 is installed on the wheel shaft 1, and the sprocket 3 is located on the outside of the motor end disk 2. The sprocket 3 and the wheel shaft 1 are rotatably installed, and there is a clearance sliding fit between the sprocket 3 and the wheel shaft 1, and the sprocket can slide axially along the wheel shaft; a locking column 3-1 that matches the teeth 2-1 of the motor end disk is provided on the side of the sprocket 3 opposite to the motor end disk 2, and the locking column can be inserted between the teeth of the motor end disk, thereby realizing the transmission engagement between the sprocket 3 and the motor end disk 2.

[0040] The outer end disc 4 is fixedly mounted on the wheel axle 1 by means of threads, and the outer end disc 4 is located on the outside of the sprocket 3. A ratchet and pawl mechanism is provided between the sprocket 3 and the outer end disc 4. When the sprocket 3 runs forward, the ratchet and pawl mechanism drives the sprocket 3 to approach the motor end disc 2, thereby realizing the transmission engagement between the sprocket 3 and the motor end disc 2.

[0041] The return spring 5 is installed between the sprocket wheel 3 and the motor end disc 2 , and the return spring 5 provides a restoring force for the sprocket wheel 3 in the direction of the outer end disc 4 .

[0042] Furthermore, a ratchet 4-1 is provided on the inner surface of the outer end disc 4 (i.e., the side of the outer end disc 4 opposite to the sprocket 3), and a circle of ratchet teeth 3-2 is provided on the outer end surface of the sprocket 3. The number of ratchet 4-1 is not limited to one, and can be multiple; see the attached Figure 3 The top action surface of the pawl 4-1 and the tooth surface of the ratchet 3-2 are mutually matched inclined surfaces. When the sprocket 3 is driven to run in the forward direction, a relative repulsive force is generated between the top action surface of the pawl 4-1 and the ratchet 3-2, thereby driving the sprocket to move along the wheel shaft 1 toward the motor end disk 2.

[0043] Furthermore, the tooth spacing between the teeth on the motor end disk 2 is slightly larger than the diameter of the locking column 3-1, so that the locking column can smoothly enter the teeth, and each tooth on the motor end disk is inclined. In this way, when the locking column just enters the teeth, as the sprocket rotates, even if the sprocket 3 loses the driving action of the ratchet and pawl mechanism, the locking column 3-1 can continue to enter the root of the tooth under the guiding action of the tooth's own inclination.

[0044] Furthermore, the number of locking columns 3 - 1 on the sprocket 3 is not limited to one, and may be multiple.

[0045] Furthermore, the motor end plate 2 is provided with a circle of screw holes (not shown in the figure) for connecting with the motor wheel body through bolts.

[0046] Furthermore, the specific structure of the sprocket 3 is as follows: it includes a cylinder, a circle of retaining walls 3-4 is provided on the inner wall of the cylinder, a bearing 3-5 is provided in the outer cylinder cavity of the retaining wall, and is installed on the wheel axle 1 through the bearing, and the bearing and the wheel axle are clearance-fitted and can slide axially along the wheel axle; the inner cylinder cavity of the retaining wall is used to install the reset spring 5; a circle of chain teeth 3-3 is provided on the outer wall of the cylinder for installing the chain; a ratchet 3-2 is processed on the outer end of the cylinder (i.e., the end of the cylinder opposite to the outer end disk), and the locking column 3-1 is provided on the outer wall of the inner end of the cylinder (i.e., the outer wall of the cylinder opposite to the motor end disk).

[0047] Furthermore, a mounting groove for mounting the pawl is provided on the inner surface of the outer end disc, and the pawl is mounted in the mounting groove via a torsion spring.

[0048] For further information, see Appendix Figure 4 A protective cover 4-2 is arranged on the outer end plate, and the protective cover covers the ratchet pawl to play a dust protection role.

[0049] Embodiment 2

[0050] The operation method of the clutch type electric bicycle sprocket drive mechanism is as follows:

[0051] When the rider rides forward, the chain drives the sprocket to run forward. When the sprocket runs forward, the pawl on the outer end plate drives the sprocket to approach the motor end plate, so that the locking post on the sprocket enters between the teeth of the motor end plate. As the sprocket continues to run forward, the locking post enters the root of the teeth under the self-guiding action of the teeth. At this time, the pawl and ratchet constraints between the sprocket and the outer end plate are lost (see Appendix Figure 5 ), which does not affect the continued operation of the subsequent sprockets, and then the sprocket drives the entire motor wheel to operate, and the vehicle body moves forward.

[0052] When the rider stops riding, the sprocket moves outward under the action of the return spring and disengages from the transmission meshing with the teeth of the motor end plate. At this time, the rotation of the motor wheel will not drive the sprocket to rotate synchronously, thereby reducing the working time of the bearing inside the sprocket and greatly improving its service life.

[0053] When the rider pedals backward, the chain drives the sprocket to rotate in the opposite direction. At this time, the ratchet on the sprocket will press down the pawl on the outer end plate, and the pawl will not limit the direction of rotation of the sprocket.

[0054] For ease of explanation, spatial relative terms such as "upper", "lower", "left", "right" and the like are used in the embodiments to illustrate the relationship of one element or feature shown in the figure relative to another element or feature. It should be understood that, in addition to the orientation shown in the figure, the spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figure is inverted, the element described as being "under" other elements or features will be positioned "on" other elements or features. Therefore, the exemplary term "under" can include both upper and lower orientations. The device can be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used here can be interpreted accordingly.

[0055] Furthermore, relational terms such as “first” and “second” and the like are merely used to distinguish one component from another having the same name, but do not necessarily require or imply any such actual relationship or order between these components.

[0056] The present invention is described above by way of example. It should be noted that, without departing from the core of the present invention, any simple deformation, modification or other equivalent replacement that can be made by those skilled in the art without inventive effort falls within the protection scope of the present invention.

Claims

1. A clutch type electric bicycle sprocket drive mechanism, characterized in that: It includes a wheel shaft, a motor end plate, a sprocket, an outer end plate and a return spring, wherein the outer end plate, the sprocket and the motor end plate are sequentially mounted on the wheel shaft from outside to inside; The outer end surface of the motor end plate is provided with a circle of teeth; The sprocket is rotatably mounted on the axle, and there is a clearance sliding fit between the sprocket and the axle, so that the sprocket can slide axially along the axle; a locking column matching the teeth of the motor end disc is arranged on the side of the sprocket opposite to the motor end disc; A ratchet and pawl mechanism is arranged between the sprocket and the outer end disc. When the sprocket rotates in the forward direction, the ratchet and pawl mechanism drives the sprocket to approach the motor end disc, thereby realizing the transmission engagement between the sprocket and the motor end disc. The return spring is installed between the sprocket and the motor end disc to provide a restoring force for the sprocket to separate from the motor end disc; The outer end disc is fixedly mounted on the wheel axle by means of threads; A ratchet pawl is arranged on the inner surface of the outer end disc, and a circle of ratchet teeth is arranged on the outer end surface of the sprocket.

2. The clutch type electric bicycle sprocket drive mechanism according to claim 1, characterized in that: The top action surface of the pawl and the tooth surface of the ratchet tooth are mutually matched inclined surfaces.

3. The clutch type electric bicycle sprocket drive mechanism according to claim 1, characterized in that: The tooth spacing between the teeth on the motor end disk is greater than the diameter of the locking column, and each tooth on the motor end disk is set at an angle. When the locking column just enters the tooth space, as the sprocket rotates, even if the sprocket loses the driving action of the ratchet and pawl mechanism, the locking column can continue to enter the tooth root under the self-inclined guiding action of the tooth.

4. The clutch type electric bicycle sprocket drive mechanism according to claim 1, characterized in that: The number of locking posts on the sprocket is multiple.

5. The clutch type electric bicycle sprocket drive mechanism according to claim 1, characterized in that: The specific structure of the sprocket is as follows: it includes a cylinder, a circle of retaining walls is arranged on the inner wall of the cylinder, a bearing is arranged in the outer cylinder cavity of the retaining wall, and is installed on the wheel axle through the bearing, and there is a clearance fit between the bearing and the wheel axle, and can slide axially along the wheel axle; the inner cylinder cavity of the retaining wall is used to install the reset spring; a circle of chain teeth is arranged on the outer wall of the cylinder for installing the chain; ratchet teeth are processed on the outer end of the cylinder, and the locking column is arranged on the outer wall of the inner end of the cylinder.

6. The clutch type electric bicycle sprocket drive mechanism according to claim 1, characterized in that: A mounting groove for mounting the pawl is arranged on the inner surface of the outer end disc, and the pawl is mounted in the mounting groove through a torsion spring.

7. The clutch type electric bicycle sprocket drive mechanism according to claim 1, characterized in that: A protective cover is arranged on the outer end disc, and the protective cover covers the ratchet pawl.

Images