Balanced type middle motor speed reducer

Abstract

The utility model relates to a balanced type middle motor reducer, and belongs to the field of motor equipment, the balanced type middle motor reducer comprises a shell, an input shaft, a reduction gear mechanism and a middle shaft assembly, the input shaft and the middle shaft assembly are both connected to the shell, the reduction gear mechanism is used for transmitting torque between the input shaft and the middle shaft assembly, and the reduction gear mechanism comprises an output gear; the output gear is coaxially located outside the middle shaft assembly, and the torque transmission point of the output gear to the middle shaft assembly is located in the middle of the middle shaft assembly in the length direction. The reduction gear mechanism comprises a reduction wheel set and a relay sleeve, the driving motor is connected to one end of the input shaft, the reduction wheel set is located at the end, away from the driving motor, of the input shaft, a stress gear and a transmission gear are coaxially connected to the relay sleeve, the reduction wheel set transmits torque to the stress gear, and the transmission gear transmits torque to the output gear. The transmission gear is flush with the output gear. The speed reducer is uniform in mass distribution, the center of gravity is centered, and overall installation and operation have high stability.

Description

Technical Field

[0001] The present application relates to the field of motor equipment, and particularly to a balanced mid-mounted motor reducer. Background Art

[0002] In the field of electric assist bicycles, a mid-mounted motor refers to a drive motor of an electric assist bicycle installed in the middle position of the vehicle body, i.e., the motor at the pedal position. The motor is connected to the vehicle body and transmits power through a chain to the rear wheel. At the same time, pedals are installed on both sides of the motor. In the case where the motor has no power, the rider can pedal to achieve human-powered riding of the bicycle.

[0003] The mid-mounted motor includes a drive motor, a reduction mechanism, and a central shaft assembly. The central shaft assembly includes a sprocket cylinder, a pedal shaft, and a transmission component. The reduction mechanism includes an input shaft and a plurality of gear pairs. The sprocket cylinder is located at the output end of the reduction mechanism. The sprocket cylinder is sleeved outside the pedal shaft. The transmission component is used to transmit the torque of the reduction mechanism to the sprocket cylinder, or transmit the torque of the pedal shaft to the sprocket cylinder. The rotating shaft of the drive motor is connected to the input shaft of the reduction mechanism. The two pedals are respectively located at both ends of the pedal shaft. All the gears of the gear pair are eccentrically arranged relative to the input shaft or the housing as a whole, which results in the imbalance of the center of gravity of the mid-mounted motor and may affect the assembly stability over a long time. Utility Model Content

[0004] In order to improve the above problems, the present application provides a balanced mid-mounted motor reducer.

[0005] A balanced mid-mounted motor reducer provided by the present application adopts the following technical solutions:

[0006] A balanced mid-mounted motor reducer includes a housing, an input shaft, a reduction gear mechanism, and a central shaft assembly. The input shaft and the central shaft assembly are both connected to the housing. The reduction gear mechanism is used to transmit torque between the input shaft and the central shaft assembly. The reduction gear mechanism includes an output gear. The output gear is coaxially located outside the central shaft assembly. The torque transmission point of the output gear to the central shaft assembly is located at the middle position in the length direction of the central shaft assembly. The reduction gear mechanism includes a reduction gear set and a relay sleeve. The drive motor is connected to one end of the input shaft. The reduction gear set is located at the end of the input shaft away from the drive motor. The relay sleeve is coaxially sleeved outside the input shaft. A force-bearing gear and a transmission gear are coaxially connected to the relay sleeve. The reduction gear set transmits torque to the force-bearing gear, and the transmission gear transmits torque to the output gear. The transmission gear and the output gear are flush.

[0007] By adopting the above technical solutions, the torque transmission structure between the input shaft and the central shaft assembly is centered relative to the input shaft and the central shaft assembly, so the overall weight distribution of the reducer is relatively uniform, and the assembly stability of the mid-mounted motor is better.

[0008] Preferably, the reduction gear mechanism further comprises a transition gear, wherein the transition gear is located between the input shaft and the middle shaft assembly, the transition gear is rotationally connected to the housing, and the transition gear is meshed with the transfer gear and the output gear at the same time.

[0009] By adopting the above technical solution, the transition gear serves as a connection between the transfer gear and the output gear. The transfer gear and the output gear can transmit the same linear speed without direct meshing. Under the premise that the input shaft and the middle shaft assembly remain unchanged, the size requirements of the transfer gear and the output gear are reduced.

[0010] Preferably, the shell includes a main shell and a secondary shell, the main shell and the secondary shell are detachably connected, the transition gear includes a wheel body and a wheel axle coaxially connected to each other, and the main shell is provided with a mounting groove for inserting one end of the wheel axle.

[0011] Preferably, the shell further comprises a backstop plate, which is detachably connected to the main shell, is located on the side of the wheel body away from the mounting groove, and is provided with a mounting hole for inserting the wheel axle.

[0012] By adopting the above technical solution, the backstop plate with the mounting hole and the main shell with the mounting groove together form a mounting structure for the transition gear, so that the transition gear can be stably rotatably mounted on the main shell.

[0013] Preferably, a PCB circuit board is also provided in the shell body, and the PCB circuit board is located between the main shell and the auxiliary shell, and is detachably connected to the main shell or the auxiliary shell.

[0014] Preferably, the PCB circuit board is connected to the main shell, and the stop plate is located in the space formed by the PCB circuit board and the inner cavity of the main shell.

[0015] Preferably, in a projection perpendicular to the surface of the backstop plate, the gear teeth of the transition gear and the output gear are both located within the surface of the backstop plate.

[0016] By adopting the above technical solution, the stop plate isolates the transition gear and the output gear relative to the PCB circuit board, thereby improving the safety of the electrical components during operation.

[0017] Preferably, an MR inductor is provided in the housing and beside the rotating shaft of the driving motor, a positioning magnetic ring is coaxially fixedly connected to the rotating shaft of the driving motor, and the positioning magnetic ring includes a plurality of staggered N-pole magnetic blocks and S-pole magnetic blocks along the circumferential direction.

[0018] By adopting the above technical solution, during the operation of the drive motor, the positioning magnetic ring and its shaft rotate synchronously, and the MR sensor determines the speed, rotation angle and other parameters of the drive motor by detecting the change of the magnetic field.

[0019] In summary, the present application includes at least one of the following beneficial technical effects:

[0020] 1. Through the settings of the output gear and the relay sleeve, the torque transmission structure between the input shaft and the middle shaft assembly is centered relative to the input shaft and the middle shaft assembly, so the overall weight distribution of the reducer is relatively uniform, and the assembly stability of the mid-mounted motor is better;

[0021] 2. Through the setting of the anti-back plate, the anti-back plate provides an installation basis for the other end of the transition gear, and at the same time isolates the transition gear and the output gear from the PCB circuit board, improving the safety of electrical components during operation. Description of the Drawings

[0022] Figure 1 is a schematic structural diagram for showing the internal structure of the housing in the embodiment of the present application.

[0023] Figure 2 is a schematic structural diagram for showing the installation structure of the anti-back plate and the PCB circuit board in the embodiment of the present application.

[0024] Description of the reference numerals: 1. Housing; 11. Main housing; 111. Installation groove; 12. Sub-housing; 13. Anti-back plate; 131. Installation hole; 14. MR sensor; 2. Driving motor; 21. Positioning magnetic ring; 3. Input shaft; 31. Gear rack; 4. Reduction gear mechanism; 41. Relay sleeve; 411. Load-bearing gear; 412. Transmission gear; 42. Reduction gear set; 421. Planetary gear; 422. Basic gear ring; 423. Connecting gear ring; 43. Transition gear; 44. Output gear; 5. PCB circuit board; 6. Middle shaft assembly; 61. Sprocket cylinder; 62. Pedal shaft; 63. Transmission component. Detailed Description of the Embodiment

[0025] The following further describes the present application in detail with reference to the attached Figure 1-2 drawings.

[0026] The embodiment of the present application discloses a balanced mid-mounted motor reducer, as Figure 1 shown, which includes a housing 1, a middle shaft assembly 6, an input shaft 3 and a reduction gear mechanism 4. The input shaft 3, the middle shaft assembly 6 and the reduction gear mechanism 4 are all installed on the housing 1, and the driving motor 2 is also installed on the housing 1. The rotating shaft of the driving motor 2 is coaxially connected with the input shaft 3 and can rotate synchronously; the reduction gear mechanism 4 is used to transmit torque from the input shaft 3 to the middle shaft assembly 6.

[0027] As Figure 1As shown, the reduction gear mechanism 4 includes a reduction gear set 42 and a relay sleeve 41. The reduction gear set 42 is located at one end of the input shaft 3 away from the drive motor 2. The relay sleeve 41 is coaxially sleeved outside the input shaft 3. A force-bearing gear 411 and a transmission gear 412 are integrally formed coaxially on the relay sleeve 41. The force-bearing gear 411 is located at one end of the relay sleeve 41 relatively close to the reduction gear set 42, and the transmission gear 412 is located at one end relatively close to the drive motor 2. During the process of torque transmission from the input shaft 3 to the relay sleeve 41 through the reduction gear set 42 to drive the relay sleeve 41, the rotational speed of the relay sleeve 41 is less than that of the input shaft 3 (in revolutions per minute).

[0028] As Figure 1 As shown, the reduction gear set 42 includes three planetary gears 421, a basic gear ring 422, and a connecting gear ring 423. A gear bracket 31 is fixedly connected to one end of the input shaft 3 away from the drive motor 2. The three planetary gears 421 are rotatably arranged on the gear bracket 31 and are arranged in a circumferential array relative to the axis of the input shaft 3. The basic gear ring 422 is fixedly connected to the housing 1, and the connecting gear ring 423 is rotatably connected to the housing 1. Both the basic gear ring 422 and the connecting gear ring 423 are coaxial with the input shaft 3. The connecting gear ring 423 is located on the side of the basic gear ring 422 facing the drive motor 2. All three planetary gears 421 are simultaneously meshed with both the basic gear ring 422 and the connecting gear ring 423. When the input shaft 3 drives the gear bracket 31 to rotate, each planetary gear 421 rolls synchronously relative to the connecting gear ring 423 and the basic gear ring 422. There is a difference in the number of teeth between the connecting gear ring 423 and the basic gear ring 422. Therefore, during the rolling of the planetary gears 421, the connecting gear ring 423 and the basic gear ring 422 can rotate relative to each other. The connecting gear ring 423 is also meshed with the force-bearing gear 411 while being meshed with the planetary gears 421, that is, the connecting gear ring 423 rotates synchronously with the relay sleeve 41. Thus, the input shaft 3 can transmit torque to the relay sleeve 41, and the rotational speed of the relay sleeve 41 is much less than that of the input shaft 3.

[0029] As Figure 1 and 2 As shown, the reduction gear mechanism 4 includes an output gear 44. The output gear 44 is coaxially connected to the middle shaft assembly 6. The middle shaft assembly 6 includes a sprocket cylinder 61, a foot pedal shaft 62, and a transmission component 63. A sprocket is fixedly connected to the end of the sprocket cylinder 61, and a bicycle chain is wound around the sprocket. Pedal plates are respectively connected to both ends of the foot pedal shaft 62. The transmission component 63 includes a one-way bearing, a synchronous sleeve, etc. The transmission component 63 is used to transmit the torque of the output gear 44 to the sprocket cylinder 61, or to transmit the torque of the foot pedal shaft 62 to the sprocket cylinder 61.

[0030] As Figure 1 and 2As shown, the housing 1 includes a main housing 11 and a sub-housing 12. The main housing 11 and the sub-housing 12 are detachably connected by bolts. The drive motor 2 is located inside the main housing 11. The reduction gear mechanism 4 further includes an intermediate gear 42. The intermediate gear 42 is located between the input shaft 3 and the middle shaft assembly 6 and is rotatably mounted inside the housing 1. The intermediate gear 42, the transmission gear 412, and the output gear 44 are flush, and the intermediate gear 42 meshes with both the transmission gear 412 and the output gear 44 simultaneously. The intermediate gear 42 includes a wheel body and a wheel shaft that are coaxially and fixedly connected to each other. An installation groove 111 for inserting one end of the wheel shaft is formed inside the main housing 11. The housing 1 further includes a retaining plate 13. The retaining plate 13 is detachably connected to the main housing 11 by bolts. The retaining plate 13 is located on the side of the wheel body facing away from the installation groove 111. An installation hole 131 for inserting the wheel shaft is formed on the retaining plate 13. Bearings that cooperate with the wheel shaft are provided both inside the installation hole 131 and inside the installation groove 111, enabling the intermediate gear 42 to rotate relative to the main housing 11 stably.

[0031] As Figure 1 and 2 shown, a PCB circuit board 5 is further provided inside the housing 1. The PCB circuit board 5 is located between the main housing 11 and the sub-housing 12 and is detachably connected to the main housing 11 by bolts. The PCB circuit board 5 is used to receive power signals or control signals to control the operation of the drive motor 2. The retaining plate 13 is located in the space formed by the PCB circuit board 5 and the inner cavity of the main housing 11. At the same time, in the projection along the direction perpendicular to the plate surface of the retaining plate 13, the teeth of the intermediate gear 42 and the output gear 44 are both within the range of the plate surface of the retaining plate 13. That is, during the operation of the mid-mounted motor, the retaining plate 13 can provide good isolation for the PCB circuit board 5, the intermediate gear 42, and the output gear 44, improving the safety of electrical components during operation.

[0032] As Figure 1 and 2 shown, an MR sensor 14 is provided inside the housing 1 beside the rotating shaft of the drive motor 2. A positioning magnetic ring 21 is coaxially and fixedly connected to the rotating shaft of the drive motor 2. The positioning magnetic ring 21 includes a number of N-pole magnetic blocks and S-pole magnetic blocks arranged alternately along the circumference. During the operation of the drive motor 2, the positioning magnetic ring 21 rotates synchronously with its rotating shaft. The MR sensor 14 detects the change in the magnetic field to judge parameters such as the rotational speed and rotational angle of the drive motor 2.

[0033] The implementation principle of a balanced mid-mounted motor reducer in an embodiment of this application is:

[0034] The reduction gear set 42 adopts the form of planetary gears 421 and a gear ring, and its circumferential distribution relative to the input shaft 3 is relatively balanced. The reduction gear set 42 and the drive motor 2 are symmetrically arranged at both ends of the input shaft 3. The relay sleeve 41, the intermediate gear 42, and the output gear 44 are relatively located at the central positions of the input shaft 3 and the central shaft assembly 6. Thus, the overall weight distribution of the in-wheel motor is also relatively balanced.

[0035] The above are all preferred embodiments of this application, and the protection scope of this application is not limited thereby. Therefore, all equivalent changes made according to the structure, shape, and principle of this application shall be covered within the protection scope of this application.

Claims

1. A balanced mid-mounted motor reducer, comprising a housing (1), an input shaft (3), a reduction gear mechanism (4) and a middle shaft assembly (6), wherein the input shaft (3) and the middle shaft assembly (6) are both connected to the housing (1), and the reduction gear mechanism (4) is used to transmit torque between the input shaft (3) and the middle shaft assembly (6), characterized in that: The reduction gear mechanism (4) comprises an output gear (44), the output gear (44) is coaxially located outside the middle shaft assembly (6), and the torque transmission point of the output gear (44) to the middle shaft assembly (6) is located at a central position in the length direction of the middle shaft assembly (6); The reduction gear mechanism (4) comprises a reduction wheel group (42) and a relay sleeve (41); the drive motor (2) is connected to one end of the input shaft (3); the reduction wheel group (42) is located at the end of the input shaft (3) away from the drive motor (2); the relay sleeve (41) is coaxially sleeved outside the input shaft (3); a force-bearing gear (411) and a transmission gear (412) are coaxially connected to the relay sleeve (41); the reduction wheel group (42) transmits torque to the force-bearing gear (411); the transmission gear (412) transmits torque to the output gear (44); and the transmission gear (412) and the output gear (44) are flush.

2. A balanced mid-mounted motor reducer according to claim 1, characterized in that: The reduction gear mechanism (4) further comprises a transition gear (43), wherein the transition gear (43) is located between the input shaft (3) and the middle shaft assembly (6), the transition gear (43) is rotationally connected to the housing (1), and the transition gear (43) is simultaneously meshed with the transmission gear (412) and the output gear (44).

3. A balanced mid-mounted motor reducer according to claim 2, characterized in that: The housing (1) comprises a main housing (11) and a secondary housing (12), wherein the main housing (11) and the secondary housing (12) are detachably connected, and the transition gear (43) comprises a wheel body and a wheel axle coaxially connected to each other, and the main housing (11) is provided with a mounting groove (111) for inserting one end of the wheel axle.

4. A balanced mid-mounted motor reducer according to claim 3, characterized in that: The housing (1) further comprises a stop plate (13), the stop plate (13) being detachably connected to the main housing (11), the stop plate (13) being located on a side of the wheel body away from the mounting groove (111), and a mounting hole (131) for inserting the wheel axle is provided on the stop plate (13).

5. A balanced mid-mounted motor reducer according to claim 4, characterized in that: A PCB circuit board (5) is also provided in the housing (1); the PCB circuit board (5) is located between the main housing (11) and the auxiliary housing (12), and is detachably connected to the main housing (11) or the auxiliary housing (12).

6. A balanced mid-mounted motor reducer according to claim 5, characterized in that: The PCB circuit board (5) is connected to the main shell (11), and the stop plate (13) is located in a space formed by the PCB circuit board (5) and the inner cavity of the main shell (11).

7. A balanced mid-mounted motor reducer according to claim 6, characterized in that: In a projection perpendicular to the plate surface of the backstop plate (13), the gear teeth of the transition gear (43) and the output gear (44) are both located within the plate surface of the backstop plate (13).

8. A balanced mid-mounted motor reducer according to claim 6, characterized in that: An MR inductor (14) is provided inside the housing (1) and beside the rotating shaft of the drive motor (2). A positioning magnetic ring (21) is coaxially fixedly connected to the rotating shaft of the drive motor (2). The positioning magnetic ring (21) includes a plurality of N-pole magnetic blocks and S-pole magnetic blocks arranged alternately along the circumferential direction.

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