Compact card-based torque sensing device

Abstract

The utility model discloses a compact card base torque sensing device, which comprises a card base arranged on a motor shaft on the outer side of an end cover of a hub motor and a torque sensing assembly on the card base, and is characterized in that the card base comprises a motor shaft sleeve and a card base shell, the motor shaft sleeve is sleeved and circumferentially fixed on the motor shaft, and the card base shell is arranged on the periphery of the motor shaft sleeve; the inner periphery of the flywheel placement part is supported on a motor shaft sleeve through a plurality of clamping base bearings, and the rear part of the outer periphery of the end cover connection part is connected with an end cover of the hub motor through a ratchet and pawl one-way clutch; the torque sensing assembly comprises a signal acquisition assembly located on the front portion of the outer periphery of the end cover connecting part and a signal transmission assembly located on the inner periphery of the end cover connecting part, and the signal acquisition assembly comprises at least one strain gauge attached to the surface of the outer periphery of the end cover connecting part and a first signal acquisition PCB electrically connected with the strain gauge. And a leading-out wire of the signal transmission assembly is led out from the front part of the card base shell. The torque sensor is simple and compact in structure, easy to assemble and maintain, and higher in torque signal acquisition precision.

Description

Technical Field

[0001] The utility model relates to a compact card-based moment sensor device. Background Art

[0002] The original electric bicycles on the market usually installed torque sensors on the bottom bracket of the middle shaft to detect and collect pedal force signals and control the speed of the electric bicycle. However, since the middle shaft torque sensor often requires the addition of structures inside the bottom bracket to be modified, there are many sensor points and lead wires, and the assembly process is complicated. In addition, the lead wires of the hub motor are located in different parts, so a set of special wiring harnesses and structures are required, resulting in high production costs.

[0003] For this reason, most electric bicycles currently directly place torque sensors on the card base outside the hub motor, thereby forming a card base torque sensor device, whose structure is usually to install a set of torque sensor components at the inner end of the card base (i.e., the end connected to the hub motor housing) through an integrated flange, and the torque sensor component is provided with a strain gauge for detecting the micro-deformation of the card base housing caused by the feedback force of the hub motor housing, thereby obtaining a torque signal; for example, the utility model patent with announcement number CN 216734643U discloses such a card base torque sensor device.

[0004] However, through practical application, we found that the existing card-based torque sensor device has the following problems:

[0005] 1. The signal acquisition component in the torque sensor assembly is set at the inner end of the connection between the card base and the wheel hub motor. It is actually installed at the end of the motor sleeve of the inner ring of the card base. Therefore, it needs to be installed deep inside the wheel hub motor housing. Not only is the structure complicated, but it is also extremely inconvenient to install and maintain. In addition, some PCB boards, coils and corresponding brackets of the signal transmission components of the torque sensor assembly need to be fixed to the motor shaft inside the wheel hub motor, which requires the wheel hub motor end cover to be disassembled for maintenance and replacement, which is inefficient and has high maintenance costs.

[0006] 2. The torque sensor assembly is arranged side by side along the axial direction of the card base at the inner side of the ratchet pawl one-way clutch, which makes the axial dimension of the entire card base elongated, occupies a large volume, and has a non-compact structure. In addition, the torque sensor assembly also needs to be equipped with a support plate structure connecting the card base and the hub motor housing, which has many parts and components, increasing the production cost.

[0007] 3. The ratchet and pawl are respectively set on the card base housing and the motor sleeve, and the strain gauge is attached to the motor sleeve or its integrated structure. As a result, when the pedal force is transmitted to the card base housing, it will be partially eliminated by the ratchet pawl and then transmitted to the hub motor housing, and finally react on the motor sleeve to produce micro deformation. This process greatly reduces the inductive sensitivity of the strain gauge, thereby affecting the detection accuracy of the torque signal. In actual use, users are often required to increase the pedal force to increase the inductive strength of the torque signal.

[0008] 4. The signal lead-out harness of the torque sensor assembly is often combined with the harness inside the hub motor and then led out through the non-card-based fixed end of the hub motor housing. When the torque sensor assembly needs to be tested or repaired separately, the signal lead-out harness of the torque sensor assembly needs to be separated from the combined harness, which is cumbersome and inefficient. Summary of the invention

[0009] The purpose of the utility model is to provide a compact card-based torque sensor device for the shortcomings of the existing card-based torque sensor device mentioned in the background technology, which is not only simple and compact in structure, easy to assemble and maintain, but also has higher torque signal acquisition accuracy.

[0010] The technical scheme of the utility model is: a compact card-based torque sensor device, comprising a card-based mounted on the motor shaft outside the end cover of the wheel hub motor and a torque sensor assembly arranged on the card-based, the card-based comprising a motor shaft sleeve that is sleeved and circumferentially fixed on the motor shaft and a card-based shell that is arranged on the periphery of the motor shaft sleeve, the torque sensor assembly comprising a signal acquisition assembly and a signal transmission assembly; the card-based shell is characterized in that the card-based shell has a flywheel placement portion located at the front and an end cover connection portion located at the rear, the inner periphery of the flywheel placement portion is supported on the motor shaft sleeve via a plurality of card-based bearings, the outer periphery rear portion of the end cover connection portion is connected to the end cover of the wheel hub motor via a ratchet pawl one-way clutch, and the signal acquisition assembly is arranged at the outer periphery front portion of the end cover connection portion;

[0011] The signal acquisition component includes at least one strain gauge attached to the outer peripheral surface of the end cover connection part and a first signal acquisition PCB board electrically connected thereto; and the signal transmission component is arranged on the inner periphery of the end cover connection part, and includes an external induction coil electrically connected to the first signal acquisition PCB board, an internal induction coil arranged corresponding to the external induction coil and a second signal acquisition PCB board electrically connected thereto, and the lead wire of the second signal acquisition PCB board is led out through the front part of the card base shell.

[0012] Furthermore, the signal transmission component in the utility model also includes an outer ring bracket and an inner ring bracket, the outer ring bracket is fixed to the inner periphery of the end cover connecting portion of the card base shell, the outer induction coil is fixed on the outer ring bracket, and the inner ring bracket is fixed on the motor sleeve, and the inner induction coil and the second signal acquisition PCB board are both fixed on the inner ring bracket.

[0013] Furthermore, the signal acquisition component in the utility model also includes an annular cover fixed to the front portion of the outer periphery of the end cover connecting portion, the annular cover covers the strain gauge, and the first signal acquisition PCB board is fixed on the inner side of the annular cover.

[0014] Furthermore, in the utility model, the outer peripheral surface of the end cover connecting portion is evenly spaced and attached with two or more strain gauges along the circumference, and these strain gauges are electrically connected to the first signal acquisition PCB board.

[0015] Furthermore, a ratchet is fixed on the outer peripheral rear portion of the inner end of the end cover connecting part in the utility model, and is connected and cooperated with a ratchet provided on the end cover of the hub motor to form the ratchet-pawl one-way clutch; or a ratchet is fixed on the outer peripheral rear portion of the inner end of the end cover connecting part, and is connected and cooperated with a ratchet provided on the end cover of the hub motor to form the ratchet-pawl one-way clutch.

[0016] Furthermore, in the utility model, an annular outer partition plate is integrally formed on the outer periphery of the end cover connecting portion, which separates the ratchet pawl one-way clutch and the signal acquisition component.

[0017] Furthermore, one end of the flywheel mounting portion in the utility model is connected to the end cover connecting portion at the rear through an enlarged step portion, and an annular inner partition is formed on the inner side of the card base shell to separate the signal transmission component and the card base bearing, and the inner periphery of the annular inner partition is provided with a toothed spline, and the second signal acquisition PCB board is provided with a back magnetic Hall element that senses the toothed spline for collecting the pedaling frequency signal.

[0018] Furthermore, the motor shaft sleeve in the utility model is provided with a lead hole parallel to the motor shaft, and the lead wire of the second signal acquisition PCB board passes through the lead hole and is led out from the front of the card base shell.

[0019] The working principle of the utility model is as follows:

[0020] As in conventional technology, the flywheel placement part of the card base housing in the utility model is used to install a transmission mechanism flywheel, such as a pulley or a sprocket, and then connected to the pedal of the electric bicycle via a corresponding belt transmission mechanism or chain transmission mechanism. The lead-out wire of the second signal acquisition PCB board in the signal transmission component is finally electrically connected to the controller of the electric bicycle.

[0021] When a person pedals an electric bicycle, the pedal force is transmitted to the card base shell (flywheel placement part) through a belt or chain transmission mechanism and drives the card base shell to rotate relative to the motor shaft sleeve. The card base shell then transmits the pedal force to the hub motor end cover through the ratchet pawl one-way clutch on the end cover connection part and drives the hub motor to rotate. At the same time, the end cover of the hub motor will give the card base shell a corresponding pawl or ratchet reaction force through the ratchet or pawl set thereon. After the pawl or ratchet on the card base shell is stressed, the card base shell will produce a micro-deformation, and the strain gauge will sense the micro-deformation and output the corresponding electrical signal, i.e., the torque signal, through the first signal acquisition PCB board. The torque signal is then wirelessly transmitted to the second signal acquisition PCB board through the internal and external induction coils in the signal transmission component, and finally output to the controller of the electric bicycle.

[0022] At the same time, the back magnetic Hall element installed on the second signal acquisition PCB board senses the toothed spline on the inner circumference of the card base shell. When the card base shell rotates and drives the toothed spline to rotate, the back magnetic Hall element senses and obtains the bicycle pedaling frequency signal and outputs it to the controller of the electric bicycle. Compared with the traditional pedaling frequency measuring structure that requires the installation of a magnetic ring, this pedaling frequency measuring mechanism makes the internal structure of the torque sensor device more compact and more effectively utilizes space.

[0023] The advantages of the utility model are:

[0024] The utility model has a simple and compact structure, is easy to assemble and maintain, and has higher torque signal acquisition accuracy. The specific advantages are as follows:

[0025] 1. The signal acquisition component of the torque sensor assembly in the utility model is arranged at the front of the ratchet pawl one-way clutch at the connection between the card base and the hub motor, that is, at the outer end of the hub motor housing, so the whole does not need to be installed deep into the hub motor housing as in conventional technology, so the structure is simplified, and installation and maintenance are extremely convenient. At the same time, the utility model does not need to disassemble the hub motor end cover for repairing and replacing the coil and corresponding bracket in its signal transmission assembly, which improves assembly efficiency and reduces maintenance costs.

[0026] 2. The torque sensor assembly in the utility model is divided into a signal collection assembly located outside the card base shell and a signal transmission assembly located inside the card base. The signal transmission assembly and the ratchet pawl one-way clutch are arranged along the radial direction of the card base, so that the axial size of the entire card base is reduced, the volume occupied by the torque sensor assembly is reduced, and its structure is more compact. In addition, the torque sensor assembly does not need to be equipped with a support plate structure for connecting the card base and the hub motor shell as in the prior art, which simplifies the parts and greatly reduces the production cost.

[0027] 3. In the utility model, since the strain gauge sensing part is located in front of the ratchet pawl one-way clutch, when it is working, the external pedal force on the card base shell will not be dissipated by the ratchet pawl one-way clutch and then transmitted to the end cover of the hub shell, and finally fed back to it to produce micro deformation, but directly fed back to itself in the form of the intermediate reaction force of the ratchet pawl, which enhances the sensitivity of the strain gauge on the card base shell, thereby greatly improving the detection accuracy of the torque signal. In actual use, the user does not need to increase the pedal force to increase the sensing intensity of the torque signal, and riding is more labor-saving.

[0028] 4. The signal lead wire of the torque sensor assembly in the utility model is led out from the front of the card base shell (the end facing away from the hub motor) and is not combined with the wiring harness inside the hub motor. When the torque sensor assembly needs to be tested or repaired separately, there is no need to perform cumbersome wiring harness separation operations, which can improve work efficiency.

[0029] 5. The back-magnetic Hall element installed on the second signal acquisition PCB board of the utility model senses the toothed spline on the inner circumference of the card base shell. When the card base shell rotates and drives the toothed spline to rotate, the back-magnetic Hall element senses and obtains the bicycle pedaling frequency signal and outputs it to the controller of the electric bicycle. Compared with the traditional pedaling frequency measuring structure that requires the installation of a magnetic ring, this pedaling frequency measuring mechanism makes the internal structure of the torque sensor device more compact and more effectively utilizes space. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The utility model is further described below in conjunction with the accompanying drawings and embodiments:

[0031] Figure 1 It is the main cross-sectional view of the structure of the utility model;

[0032] Figure 2 for Figure 1 AA section view;

[0033] Figure 3 for Figure 2 BB cross-section diagram;

[0034] Figure 4 It is a three-dimensional structural schematic diagram of the utility model;

[0035] Figure 5 The figure is a schematic diagram of the assembly structure of the utility model on the wheel hub motor.

[0036] Wherein: 1. motor shaft; 2. motor shaft sleeve; 201. lead hole; 3. card base shell; 301. flywheel placement part; 302. end cover connection part; 302a. annular outer partition; 4. signal acquisition component; 401. strain gauge; 402. first signal acquisition PCB board; 403. annular cover; 5. signal transmission component; 501. outer induction coil; 502. inner induction coil; 503. second signal acquisition PCB board; 504. lead wire; 505. outer ring bracket; 506. inner ring bracket; 6. card base bearing; 7. ratchet; 8. pawl; 9. step part; 10. annular inner partition; 10a. toothed spline; 11. hub motor; 11a. end cover; 12. transmission mechanism flywheel. DETAILED DESCRIPTION

[0037] Example: The following combination Figure 1~Figure 5 The specific implementation of the compact card-based torque sensor device provided by the utility model is described as follows:

[0038] First, Figure 1 and Figure 5 As shown, the easy-to-assemble hub motor end cover card base connection mechanism provided by the utility model is the same as the known technology, which has a card base installed on the motor shaft 1 outside the end cover 11a of the hub motor 11 and a torque sensor component arranged on the card base, and the card base is mainly composed of a motor sleeve 2, a card base bearing 3 and a card base bearing 6. Like the conventional setting, the motor sleeve 2 is sleeved and circumferentially fixed on the motor shaft 1, and the card base housing 3 is arranged on the periphery of the motor sleeve 2. The torque sensor component is composed of a signal acquisition component 4 and a signal transmission component 5.

[0039] Further integration Figure 1 and Figure 2 As shown, the card base housing 3 has a flywheel mounting portion 301 located at the front and an end cover connecting portion 302 located at the rear. The outer periphery of the flywheel mounting portion 301 is used to install the transmission mechanism flywheel 12, which is a sprocket in this embodiment, and is further connected to the pedal of the electric bicycle via a chain transmission mechanism, while the inner periphery of the flywheel mounting portion 301 is supported on the motor sleeve 2 via two card base bearings 6 placed side by side. The core structural improvement of the utility model is that the outer rear portion of the end cover connecting portion 302 is connected to the end cover 11a of the hub motor 11 via a ratchet pawl one-way clutch, and the signal acquisition component 4 is arranged at the outer front portion of the end cover connecting portion 302, and the signal transmission component 5 is arranged at the inner periphery of the end cover connecting portion 302.

[0040] Combination Figure 1 , Figure 2 and Figure 5As shown, in this embodiment, a ratchet 7 is fixed on the outer periphery rear portion of the inner end of the end cover connecting portion 302, which is connected and cooperated with the pawl 8 provided on the end cover 11a of the hub motor 11 to form the ratchet pawl one-way clutch. In addition, an annular outer partition plate 302a is integrally formed on the outer periphery of the end cover connecting portion 302 to separate the ratchet pawl one-way clutch and the signal acquisition component 4.

[0041] Recombination Figure 2 , Figure 3 and Figure 4 As shown, the signal acquisition component 4 in this embodiment includes two strain gauges 401 attached to the outer peripheral surface of the end cover connection part 302 and a first signal acquisition PCB board 402 electrically connected thereto. In this embodiment, the two strain gauges 401 are evenly spaced and attached to the outer peripheral surface of the end cover connection part 302 along the circumference, and these strain gauges 401 are electrically connected to the first signal acquisition PCB board 402, and the first signal acquisition PCB board 402 is made of a flexible substrate and can be bent into an arc. The signal acquisition component 4 also includes an annular cover 403 fixed to the front of the outer periphery of the end cover connection part 302, the annular cover 403 covers the strain gauges 401, and the first signal acquisition PCB board 402 is fixed inside the annular cover 403.

[0042] The signal transmission component 5 is arranged on the inner periphery of the end cap connection part 302, and includes an outer induction coil 501 electrically connected to the first signal acquisition PCB board 402, an inner induction coil 502 arranged corresponding to the outer induction coil 501, and a second signal acquisition PCB board 503 electrically connected thereto, and the lead wire 504 of the second signal acquisition PCB board 503 is led out through the front part of the card base shell 3. The signal transmission component 5 also includes an outer ring bracket 505 and an inner ring bracket 506, the outer ring bracket 505 is fixed on the inner periphery of the end cap connection part 302 of the card base shell 5, the outer induction coil 501 is fixed on the outer ring bracket 505, and the inner ring bracket 506 is fixed on the motor shaft sleeve 2, and the inner induction coil 502 and the second signal acquisition PCB board 503 are both fixed on the inner ring bracket 506. Similarly, the second signal acquisition PCB board 503 is also made of a flexible substrate and can be bent into an arc.

[0043] Combination Figure 1 and Figure 2 As shown, in this embodiment, one end of the flywheel mounting portion 301 is connected to the end cover connecting portion 302 at the rear through an enlarged step portion 9, and the inner side of the card base shell 3 is formed with an annular inner partition 10 that separates the signal transmission component 5 and the card base bearing 6, and the inner periphery of the annular inner partition 10 is provided with a toothed spline 10a, and the second signal acquisition PCB board 503 is provided with a back magnetic Hall element that senses the toothed spline 10a for collecting the pedaling frequency signal.

[0044] Recombination Figure 1 and Figure 5 As shown, in this embodiment, a lead hole 201 parallel to the motor shaft 1 is opened on the motor sleeve 2, and the lead wire 504 of the second signal acquisition PCB board 503 passes through the lead hole 201 and is led out from the front of the card base shell 3.

[0045] The working principle of the utility model is as follows:

[0046] As in conventional technology, the flywheel placement part 301 of the card base housing 3 in the utility model is used to install the transmission mechanism flywheel 12, such as a sprocket, and then connected to the pedal of the electric bicycle via the chain transmission mechanism. The lead wire 504 of the second signal acquisition PCB board 503 in the signal transmission component 5 is finally electrically connected to the controller of the electric bicycle.

[0047] When a person pedals the electric bicycle, the pedal force is transmitted to the card base housing 3 (flywheel placement part 301) through the chain transmission mechanism and drives the card base housing 3 to rotate relative to the motor shaft sleeve 2. The card base housing 3 then transmits the pedal force to the end cover 11a of the hub motor 11 through the ratchet pawl one-way clutch on the end cover connection part 302 and drives the hub motor 11 to rotate. At the same time, the end cover 11a of the hub motor 11 will give the card base housing 3 a corresponding reaction force of the pawl 8 through the ratchet 7 set thereon, and the pawl 8 on the card base housing 3 will cause the card base housing 3 to produce a micro deformation after the force is applied, and the strain gauge 401 senses the micro deformation and outputs a corresponding electrical signal, i.e., a torque signal, through the first signal acquisition PCB board 402. The torque signal is then wirelessly transmitted between the inner induction coil 502 and the outer induction coil 501 in the signal transmission component 5 to the second signal acquisition PCB board 503, and finally output to the controller of the electric bicycle.

[0048] At the same time, the back magnetic Hall element installed on the second signal acquisition PCB board 503 senses the toothed spline 10a on the inner circumference of the card base housing 3. When the card base housing 3 rotates and drives the toothed spline 10a to rotate, the back magnetic Hall element senses and obtains the bicycle pedaling frequency signal, and outputs it to the controller of the electric bicycle. Compared with the traditional pedaling frequency measuring structure that requires the installation of a magnetic ring, this pedaling frequency measuring mechanism makes the internal structure of the torque sensor device more compact and more effectively utilizes space.

[0049] Of course, the above embodiments are only for illustrating the technical concept and features of the utility model, and their purpose is to enable people familiar with the technology to understand the content of the utility model and implement it accordingly, and they cannot be used to limit the protection scope of the utility model. Any modifications made according to the spirit of the main technical solution of the utility model should be included in the protection scope of the utility model.

Claims

1. A compact card-base torque sensor device, comprising a card-base mounted on a motor shaft (1) outside an end cover (11a) of a hub motor (11) and a torque sensor component arranged on the card-base, the card-base comprising a motor shaft sleeve (2) sleeved and circumferentially fixed on the motor shaft (1) and a card-base housing (3) arranged on the periphery of the motor shaft sleeve (2), the torque sensor component comprising a signal acquisition component (4) and a signal transmission component (5); characterized in that The card base housing (3) comprises a flywheel placement portion (301) located at the front and an end cover connection portion (302) located at the rear, the inner periphery of the flywheel placement portion (301) being supported on the motor shaft sleeve (2) via a plurality of card base bearings (6), while the outer periphery rear portion of the end cover connection portion (302) is connected to the end cover (11a) of the hub motor (11) via a ratchet pawl one-way clutch, and the signal acquisition component (4) is arranged at the outer periphery front portion of the end cover connection portion (302); The signal acquisition component (4) comprises at least one strain gauge (401) attached to the outer peripheral surface of the end cover connection part (302) and a first signal acquisition PCB board (402) electrically connected thereto; and the signal transmission component (5) is arranged on the inner periphery of the end cover connection part (302), and comprises an external induction coil (501) electrically connected to the first signal acquisition PCB board (402), an internal induction coil (502) arranged corresponding to the external induction coil (501) and a second signal acquisition PCB board (503) electrically connected thereto, wherein the lead wire (504) of the second signal acquisition PCB board (503) is led out through the front part of the card base shell (3).

2. The compact card-based torque sensor device according to claim 1 is characterized in that The signal transmission component (5) further comprises an outer ring bracket (505) and an inner ring bracket (506); the outer ring bracket (505) is fixed to the inner periphery of the end cover connecting portion (302) of the card base housing (3); the outer induction coil (501) is fixed to the outer ring bracket (505); the inner ring bracket (506) is fixed to the motor shaft sleeve (2); and the inner induction coil (502) and the second signal acquisition PCB board (503) are both fixed to the inner ring bracket (506).

3. The compact card-based torque sensor device according to claim 1 is characterized in that The signal acquisition component (4) further comprises an annular cover (403) fixed to the front portion of the outer periphery of the end cover connection portion (302), the annular cover (403) covering the strain gauge (401), and a first signal acquisition PCB board (402) fixed inside the annular cover (403).

4. The compact card-based torque sensor device according to claim 1 or 3, characterized in that Two or more strain gauges (401) are attached to the outer peripheral surface of the end cover connecting portion (302) at even intervals along the circumference, and the strain gauges (401) are all electrically connected to the first signal acquisition PCB board (402).

5. The compact card-based torque sensor device according to claim 1, characterized in that A ratchet (7) is fixed on the outer rear portion of the inner end of the end cover connecting portion (302), and is connected and matched with a ratchet (8) provided on the end cover (11a) of the hub motor (11) to form the ratchet-pawl one-way clutch; or a ratchet (8) is fixed on the outer rear portion of the inner end of the end cover connecting portion (302), and is connected and matched with a ratchet (7) provided on the end cover (11a) of the hub motor (11) to form the ratchet-pawl one-way clutch.

6. The compact card-based torque sensor device according to claim 1 or 5, characterized in that An annular outer partition plate (302a) is integrally formed on the outer periphery of the end cover connecting portion (302) for separating the ratchet pawl one-way clutch and the signal acquisition component (4).

7. The compact card-based torque sensor device according to claim 1 is characterized in that One end of the flywheel placement portion (301) is connected to the end cover connection portion (302) at the rear via an enlarged step portion (9), and an annular inner partition (10) is formed on the inner side of the card base housing (3) for separating the signal transmission component (5) and the card base bearing (6), and a toothed spline (10a) is provided on the inner periphery of the annular inner partition (10), and a back magnetic Hall element for sensing the toothed spline (10a) is provided on the second signal acquisition PCB board (503) for collecting a pedaling frequency signal.

8. The compact card-based torque sensor device according to claim 1, characterized in that The motor shaft sleeve (2) is provided with a lead hole (201) parallel to the motor shaft (1); a lead wire (504) of the second signal acquisition PCB board (503) passes through the lead hole (201) and is led out from the front of the card base housing (3).

Images