Torque sensing assembly and interior permanent magnet motor
By employing a spline groove and limiting ring structure in the torque sensing component of the electric bicycle's central shaft torque sensor, the problem of outer ring movement was solved, achieving high-precision detection and stable connection, and improving the speed measurement accuracy and reliability of the central motor.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHEJIANG LUYUAN ELECTRIC VEHICLE
- Filing Date
- 2025-07-02
- Publication Date
- 2026-06-23
AI Technical Summary
The outer ring of the torque sensor for the central shaft of existing electric bicycles is prone to shifting, which reduces the detection accuracy.
The torque sensing components, including a torque converter, a limit ring, and a positioning component, are used to ensure that the inner ring is fixed to the central shaft and the outer ring is fixed relative to the motor housing through structures such as spline grooves and spline mating, limit grooves and protrusions, and positioning grooves and bearings, thus achieving a stable connection.
This improved the detection accuracy of the torque sensor and the speed measurement accuracy of the mid-mounted motor, ensuring the reliability and stability of the sensor.
Smart Images
Figure CN224392878U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of mid-drive motor technology, and in particular to a torque sensing component and a mid-drive motor. Background Technology
[0002] Current electric bicycles typically include a torque sensor for detecting the torque of the bicycle's bottom bracket and a speed sensor for detecting the bicycle's speed. When detecting the bottom bracket torque, the excitation coil within the torque sensor and the corresponding detection coil work together to generate a torque detection signal. However, in related technologies, the fixed outer tube of the bottom bracket torque sensor in electric-assist bicycles or other bicycles is a segmented structure with a loose fit. This makes the outer ring of the torque sensor prone to shifting during actual use, reducing detection accuracy. Utility Model Content
[0003] The purpose of this invention is to provide a torque sensing component that has good installation stability and is not prone to shifting during testing, thus ensuring detection accuracy.
[0004] The purpose of this utility model is also to provide a mid-drive motor, which has good speed measurement accuracy and reliability.
[0005] To achieve this objective, the present invention adopts the following technical solution:
[0006] This utility model discloses a torque sensing component, which is installed between a central shaft and a motor housing. The torque sensing component includes: a torque converter having an inner ring and an outer ring, the inner ring having a spline groove that mates with a spline on the central shaft, a signal line of the torque converter being connected to the outer ring and passing through the motor housing along the axial direction of the central shaft; a limiting ring installed in a mounting hole in the motor housing, the limiting ring being sleeved on the first end of the torque converter and limiting the outer ring along the circumference of the torque converter; and two positioning members installed on the central shaft and respectively abutting against the first and second ends of the inner ring.
[0007] In some embodiments, one of the inner peripheral wall of the limiting ring and the outer peripheral wall of the outer ring is provided with a limiting groove extending axially along the central axis, and the other of the inner peripheral wall of the limiting ring and the outer peripheral wall of the outer ring is provided with a limiting protrusion, which can be inserted into the limiting groove.
[0008] In some specific embodiments, there are multiple limiting grooves and multiple limiting protrusions. The multiple limiting grooves are distributed circumferentially along the central axis, and the multiple limiting protrusions are distributed circumferentially along the central axis. The multiple limiting grooves and the multiple limiting protrusions are arranged in a one-to-one correspondence.
[0009] In some embodiments, the end of the limiting ring is provided with a limiting part, the mounting hole has a stepped surface, and a limiting groove that cooperates with the limiting part is provided on the stepped surface.
[0010] In some embodiments, the central shaft is provided with a retaining ring groove, and one of the positioning elements is a positioning retaining ring installed in the retaining ring groove, the positioning retaining ring abutting against the first end of the inner ring.
[0011] In some embodiments, the mounting hole includes a first hole and a second hole, the diameter of the first hole being larger than that of the second hole, the limiting ring being mounted in the first hole and abutting against the stepped surface formed by the first hole and the second hole; one of the positioning elements is a positioning bearing mounted in the second hole, the positioning bearing abutting against the second end of the inner ring.
[0012] In some specific embodiments, the torque sensing assembly further includes an external oil seal, which is mounted on the central shaft and located on the side of the positioning bearing opposite to the second end of the inner ring.
[0013] In some embodiments, the torque sensing assembly further includes an inner oil seal, which is installed between the radially outer side of the torque generator and the motor housing, and is disposed near the first end of the inner ring.
[0014] In some specific embodiments, the torque sensing component further includes a sealant and a sealing plug. The sealant fills the sealed cavity defined by the motor housing, the inner oil seal, and the torque generator. The signal line is fixed relative to the sealed cavity by the sealant. The sealing plug is sleeved on the signal line, and one end of the sealing plug extends into the sealed cavity.
[0015] This utility model also discloses a mid-mounted motor, including a central shaft, a motor housing, and a torque sensing component as described above. The motor housing is provided with a mounting hole, the central shaft passes through the mounting hole, and the torque sensing component is sleeved on the central shaft and installed in the mounting hole.
[0016] The torque sensing component of this invention offers the following advantages: During actual installation, first, a positioning component is installed inside the motor housing. Then, the torque converter is installed on the central shaft. Next, another positioning component is installed on the central shaft and abuts against the second end of the inner ring of the torque converter. A limiting ring is then installed into the mounting hole in the motor housing. Finally, the central shaft, on which the torque converter is mounted, is inserted into the mounting hole. Because the inner ring of the torque converter is connected via a spline groove and spline, it is fixed circumferentially. The two positioning components abut against the first and second ends of the inner ring, respectively, fixing it axially. The limiting ring limits the outer ring circumferentially along the torque converter. Due to the structural characteristics of the torque converter itself, the inner ring axially restricts the outer ring. Thus, both the axial and circumferential directions of the torque converter are stably restricted. The inner ring of the torque converter can rotate with the central shaft, while the outer ring is fixed relative to the motor housing, ensuring the accuracy of the torque converter's detection.
[0017] The beneficial effects of the mid-drive motor of this utility model are that, due to the torque sensing component mentioned above, the speed measurement accuracy and reliability of the mid-drive motor are better.
[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of the cooperation structure between the torque sensing component and the central shaft according to an embodiment of the present utility model;
[0020] Figure 2 This is a schematic diagram of the cooperation structure between the torque sensing component, the central shaft, and the motor housing according to an embodiment of the present utility model;
[0021] Figure 3 yes Figure 2 A schematic diagram of the structure from another direction shown.
[0022] Figure 4 yes Figure 2 An exploded view of the structure shown;
[0023] Figure 5 yes Figure 2 A cross-sectional view of the structure shown.
[0024] Figure label:
[0025] 100. Torque sensing assembly; 110. Torque generator; 111. Inner ring; 112. Outer ring; 1121. Signal line; 1122. Limiting protrusion; 120. Limiting ring; 121. Limiting groove; 122. Limiting part; 130. Sealing plug; 140. Positioning circlip; 150. Positioning bearing; 160. Outer oil seal; 170. Inner oil seal; 180. Sealing cavity;
[0026] 200, central shaft; 300, motor housing; 310, mounting hole; 311, first hole; 312, second hole. Detailed Implementation
[0027] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.
[0028] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0029] In the description of this embodiment, the terms "upper," "lower," "left," "right," "front," and "rear," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.
[0030] This utility model discloses a torque sensing component 100, referenced... Figure 1 , Figure 2 and Figure 3 As shown, the torque sensing assembly 100 is installed between the central shaft 200 and the motor housing 300, for reference. Figure 5As shown, the torque sensing assembly 100 includes a torque converter 110, a limiting ring 120, and two positioning members. The torque converter 110 has an inner ring 111 and an outer ring 112. The inner ring 111 of the torque converter 110 is provided with a spline groove that mates with the spline on the central shaft 200. The signal line 1121 of the torque converter 110 is connected to the outer ring 112 and passes through the motor housing 300 along the axial direction of the central shaft 200. The limiting ring 120 is installed in the mounting hole 310 of the motor housing 300. The limiting ring 120 is sleeved on the first end of the torque converter 110 and limits the outer ring 112 along the circumferential direction of the torque converter 110. The two positioning members are installed on the central shaft 200 and respectively abut against the first end and the second end of the inner ring 111. Understandably, during the actual installation process, one positioning component is first installed inside the motor housing 300, then the torque converter 110 is installed on the central shaft 200, and then another positioning component is installed on the central shaft 200, abutting against the second end of the inner ring 111 of the torque converter 110. Then, the limiting ring 120 is installed into the mounting hole 310 of the motor housing 300. Finally, the central shaft 200 with the torque converter 110 is inserted into the mounting hole 310. Since the inner ring 111 of the torque converter 110 is connected through the spline groove and spline, the inner ring 111 is fixed in the circumferential direction. The two positioning components abut against the first and second ends of the inner ring 111, respectively, thus fixing the inner ring 111 in the axial direction. The limiting ring 120 limits the outer ring 112 along the circumferential direction of the torque converter 110. Due to the structural characteristics of the torque converter 110 itself, the inner ring 111 restricts the outer ring 112 in the axial direction. Thus, the torque converter 110 is stably restricted in both the axial and circumferential directions. The inner ring 111 of the torque converter 110 can rotate together with the central shaft 200, while the outer ring 112 is fixed relative to the motor housing 300, ensuring the detection accuracy of the torque converter 110.
[0031] It should be noted that the torque generator 110 is existing technology, and the structure of its inner ring 111 and outer ring 112 can be obtained from existing technology. Therefore, the specific structure and testing principle of the inner ring 111 and outer ring 112 of the torque generator 110 will not be described here.
[0032] Optionally, the limiting ring 120 is made of nylon reinforced with glass fiber and is injection molded in one piece to ensure the strength of the parts while facilitating the molding and manufacturing of the parts.
[0033] refer to Figure 4As shown, the inner peripheral wall of the limiting ring 120 is provided with a limiting groove 121 extending axially along the central axis 200, and the outer peripheral wall of the outer ring 112 is provided with a limiting protrusion 1122, which can be inserted into the limiting groove 121. It is understood that during actual assembly, when the central axis 200 with the torque generator 110 is inserted into the mounting hole 310, the limiting protrusion 1122 can be inserted into the limiting groove 121. The cooperation between the limiting groove 121 and the limiting protrusion 1122 achieves the fixation of the limiting ring 120 and the outer ring 112, ensuring that the outer ring 112 remains fixed during testing, thereby improving the testing accuracy of the torque generator 110.
[0034] Optionally, there are multiple limiting grooves 121 and multiple limiting protrusions 1122. The multiple limiting grooves 121 are distributed circumferentially along the central axis 200, and the multiple limiting protrusions 1122 are distributed circumferentially along the central axis 200. The multiple limiting grooves 121 and multiple limiting protrusions 1122 are set in a one-to-one correspondence. Through the one-to-one cooperation of the multiple limiting grooves 121 and multiple limiting protrusions 1122, the connection stability between the limiting ring 120 and the outer ring 112 can be improved, ensuring that the outer ring 112 remains fixed during the test, thereby improving the testing accuracy of the torque generator 110.
[0035] It should be noted that in other embodiments of this utility model, the inner peripheral wall of the limiting ring 120 is provided with a limiting protrusion 1122 extending axially along the central axis 200, and another limiting groove 121 is provided on the outer peripheral wall of the outer ring 112. The shape and number of the limiting protrusion 1122 and the limiting groove 121 can be adjusted according to actual needs, and no specific limitation is made here on the number of the limiting protrusion 1122 and the limiting groove 121.
[0036] Optional, see reference Figure 4 As shown, the end of the limiting ring 120 is provided with a limiting part 122, and the mounting hole 310 of the motor housing 300 has a stepped surface, on which a limiting groove that mates with the limiting part 122 is provided. It can be understood that the mate between the limiting part 122 and the limiting groove can improve the stability between the limiting ring 120 and the motor housing 300, preventing relative rotation between the limiting ring 120 and the motor housing 300, thereby ensuring that the outer ring 112 remains fixed during testing, thus improving the testing accuracy of the torque converter 110.
[0037] Optional, see reference Figure 5As shown, the central shaft 200 is provided with a snap ring groove, one of the positioning components being a positioning snap ring 140 installed in the snap ring groove, which abuts against the first end of the inner ring 111. It is understandable that using a snap ring as a positioning component is advantageous because it simplifies the structure, facilitates installation, and reduces manufacturing costs. Furthermore, it effectively limits the axial movement of the inner ring 111, reducing the possibility of movement during testing and thus improving the testing accuracy of the torque converter 110.
[0038] Optional, see reference Figure 5 As shown, the mounting hole 310 includes a first hole 311 and a second hole 312. The diameter of the first hole 311 is larger than that of the second hole 312. The limiting ring 120 is installed in the first hole 311 and abuts against the stepped surface formed by the first hole 311 and the second hole 312. One of the positioning components is a positioning bearing 150 installed in the second hole 312, which abuts against the second end of the inner ring 111. It can be understood that using the positioning bearing 150 as a positioning component can, on the one hand, provide good support for the central shaft 200, reduce the friction between the central shaft 200 and the motor housing 300 during rotation, and help extend the service life of the central shaft 200 and the motor housing 300. On the other hand, it can better limit the axial movement of the inner ring 111, reduce the possibility of the inner ring 111 moving during the test, and improve the testing accuracy of the torque converter 110.
[0039] Optional, see reference Figure 5 As shown, the torque sensing assembly 100 also includes an outer oil seal 160, which is mounted on the central shaft 200 and located on the side of the positioning bearing 150 opposite to the inner ring 111. It is understood that the outer oil seal 160 effectively prevents impurities from entering the interior of the motor housing 300, ensuring a relatively clean internal environment for the motor.
[0040] Optional, see reference Figure 5 As shown, the torque sensing assembly 100 also includes an inner oil seal 170, which is installed between the radially outer side of the torque converter 110 and the motor housing 300, and is located near the first end of the inner ring 111. The inner oil seal 170 and the outer oil seal 160 form a double-layer sealing structure, further preventing impurities from entering the interior of the motor housing 300 and ensuring a relatively clean internal environment for the motor.
[0041] In some specific embodiments, the torque sensing assembly 100 further includes sealant and a sealing plug 130. The sealant fills the sealed cavity 180 defined by the motor housing 300, the inner oil seal 170, and the torque generator 110. The signal line 1121 of the torque generator 110 is fixed relative to the sealed cavity 180 by the sealant. The sealing plug 130 is sleeved on the signal line 1121, with one end of the sealing plug 130 extending into the sealed cavity 180. It is understood that the signal line 1121 is used for signal transmission between the torque generator 110 and the external control system. The sealant fixes the signal line 1121 relative to the sealed cavity 180, ensuring the stability of the signal line 1121 and preventing it from being pulled away from the outer ring 112 under external force. Furthermore, the sealant filling the sealed cavity 180 further prevents impurities from entering the interior of the motor housing 300, ensuring a relatively clean internal environment for the motor. The sealing plug 130 reinforces the signal line 1121, further improving its stability.
[0042] This utility model also discloses a mid-drive motor, including a central shaft 200, a motor housing 300, and a torque sensing component 100 as described above. The motor housing 300 has a mounting hole 310, the central shaft 200 passes through the mounting hole 310, and the torque sensing component 100 is sleeved on the central shaft 200 and mounted in the mounting hole 310. Due to the presence of the torque sensing component 100 described above, this mid-drive motor has better speed measurement accuracy and reliability.
[0043] In the description of this specification, references to terms such as "some embodiments," "other embodiments," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.
[0044] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. A torque sensing component, characterized in that, The torque sensing component is installed between the central shaft (200) and the motor housing (300), and the torque sensing component includes: A torque converter (110) has an inner ring (111) and an outer ring (112). The inner ring (111) is provided with a spline groove that mates with the spline on the central shaft (200). The signal line (1121) of the torque converter (110) is connected to the outer ring (112) and passes through the motor housing (300) along the axial direction of the central shaft (200). A limiting ring (120) is installed in the mounting hole (310) of the motor housing (300). The limiting ring (120) is sleeved on the first end of the torque generator (110) and limits the outer ring (112) along the circumference of the torque generator (110). Two positioning elements are mounted on the central shaft (200) and respectively abut against the first and second ends of the inner ring (111).
2. The torque sensing component according to claim 1, characterized in that, One of the inner peripheral wall of the limiting ring (120) and the outer peripheral wall of the outer ring (112) is provided with a limiting groove (121) extending axially along the central axis (200), and the other of the inner peripheral wall of the limiting ring (120) and the outer peripheral wall of the outer ring (112) is provided with a limiting protrusion (1122), which can be inserted into the limiting groove (121).
3. The torque sensing component according to claim 2, characterized in that, There are multiple limiting grooves (121) and multiple limiting protrusions (1122). The multiple limiting grooves (121) are distributed circumferentially along the central axis (200), and the multiple limiting protrusions (1122) are distributed circumferentially along the central axis (200). The multiple limiting grooves (121) and the multiple limiting protrusions (1122) are arranged in a one-to-one correspondence.
4. The torque sensing component according to claim 1, characterized in that, The end of the limiting ring (120) is provided with a limiting part (122), and the mounting hole (310) has a stepped surface, and a limiting groove that cooperates with the limiting part (122) is provided on the stepped surface.
5. The torque sensing component according to claim 1, characterized in that, The central shaft (200) is provided with a retaining ring groove, and one of the positioning components is a positioning retaining ring (140) installed in the retaining ring groove, and the positioning retaining ring (140) abuts against the first end of the inner ring (111).
6. The torque sensing component according to claim 1, characterized in that, The mounting hole (310) includes a first hole (311) and a second hole (312), the diameter of the first hole (311) is larger than that of the second hole (312), the limiting ring (120) is installed in the first hole (311) and abuts against the stepped surface formed by the first hole (311) and the second hole (312); one of the positioning elements is a positioning bearing (150) installed in the second hole (312), the positioning bearing (150) abuts against the second end of the inner ring (111).
7. The torque sensing component according to claim 6, characterized in that, The torque sensing assembly also includes an outer oil seal (160), which is mounted on the central shaft (200) and located on the side of the positioning bearing (150) away from the second end of the inner ring (111).
8. The torque sensing component according to claim 1, characterized in that, The torque sensing assembly also includes an inner oil seal (170), which is installed between the radial outer side of the torque generator (110) and the motor housing (300), and is located near the first end of the inner ring (111).
9. The torque sensing component according to claim 8, characterized in that, The torque sensing assembly also includes a sealant and a sealing plug (130). The sealant is filled in the sealed cavity (180) defined by the motor housing (300), the inner oil seal (170), and the torque generator (110). The signal line (1121) is fixed relative to the sealed cavity (180) by the sealant. The sealing plug (130) is sleeved on the signal line (1121), and one end of the sealing plug (130) extends into the sealed cavity (180).
10. A mid-drive motor, characterized in that, The device includes a central shaft (200), a motor housing (300), and a torque sensing component as described in any one of claims 1-9. The motor housing (300) is provided with a mounting hole (310), the central shaft (200) passes through the mounting hole (310), and the torque sensing component is sleeved on the central shaft (200) and mounted in the mounting hole (310).