Middle motor torque sensor

Abstract

The utility model discloses a central motor torque sensor, which comprises a motor main body, a central shaft, an induction shaft sleeve, a movable seat plate, a static seat, a left bearing and a right bearing, the motor main body is provided with a middle pipe. A strain gauge is pasted on the induction shaft sleeve. The middle shaft is rotatably arranged in the middle pipe in a penetrating manner, spline teeth are arranged on the middle shaft, the induction shaft sleeve is in transmission connection with the middle shaft through the spline teeth, the movable seat plate fixedly sleeves the induction shaft sleeve, a ratchet wheel matched with the induction shaft sleeve in a transmission sleeving manner is arranged on the right side of the action plate, a large gear is arranged on the outer ring of the ratchet wheel, and a crankset is mounted on the right side of the large gear in a pressing manner through five claws; the movable seat plate is provided with a movable seat, the movable seat is provided with a sending end PCB, a sending end coil and a magnetic ring, the static seat is installed on the assembly disc, and the static seat is provided with a receiving end PCB and a receiving end coil. According to the utility model, the torsion borne by the center shaft is measured through the strain gauges, and the measured torque signal is continuous, real-time and accurate.

Description

TECHNICAL FIELD

[0001] The utility model relates to the manufacturing technology of torque sensor, in particular to a kind of middle motor torque sensor used on electric bicycle. BACKGROUND

[0002] In this era of nationwide fitness, green travel, bicycle sports, with its close natural sports ground, aerobic exercise fitness, has been popular among more and more people.Electric assist bicycle as a new kind of bicycle, compared with traditional non-assisted bicycle and pure electric two-wheeled electric vehicle, electric assist bicycle can intelligently provide power according to the user's effort, can effectively reduce the user's fatigue while ensuring the user's riding experience and riding safety.

[0003] The commonly used sensors of electric assist bicycle in the market at present include speed sensor, pseudo torque sensor and torque sensor.The speed sensor can only sense the speed of user's pedaling or the speed of bicycle running, and cannot effectively feedback the user's intention.The pseudo torque sensor simulates the user's effort signal by processing speed signal, which is better than speed sensor in experience, but still cannot accurately feedback.The torque sensor measures the size of user's pedaling force and pedaling speed (torque sensor generally includes speed sensor) when riding, and can accurately feedback (controller adjusts motor output power according to torque signal) according to user's intention (effort size) in real time.Torque sensor is being more and more widely accepted by electric assist vehicle system. SUMMARY

[0004] The utility model provides a kind of middle motor torque sensor to solve the technical problem of the above prior art, which has simple structure, easy installation, and can ensure signal transmission continuity and accuracy.

[0005] The technical solution adopted by the utility model to solve the above technical problem is:

[0006] The utility model provides a kind of middle motor torque sensor, including motor body, middle shaft, induction shaft sleeve, dynamic seat plate, static seat and left bearing and right bearing;The bottom of motor body is equipped with middle pipe, and the surface of induction shaft sleeve is pasted with strain gauge;Middle shaft is rotatably supported and is arranged in middle pipe by left end bearing, and the middle part of this middle shaft is profiled with spline teeth, and induction shaft sleeve is connected by spline teeth set transmission, and right bearing is positioned and set in the middle part of induction shaft sleeve and is rotatably supported and cooperated with the right end port of middle pipe;Dynamic seat plate is fixedly set on induction shaft sleeve and is located at the right side of right bearing, and the right side of the dynamic plate is equipped with ratchet wheel matched with induction shaft sleeve transmission, and the outer ring of ratchet wheel is equipped with large gear, and the right side of large gear is press-fitted with toothed disc;Dynamic seat plate is fixedly installed on the left end surface of dynamic seat, and the dynamic seat is fixedly installed with sending end PCB, sending end coil and magnetic ring, and static seat is fixedly installed on the assembly disc profiled on the right end of middle pipe, and the static seat is fixedly installed with receiving end PCB, receiving end coil.

[0007] To optimize the above technical solutions, the specific measures taken also include:

[0008] The right end surface of the above-mentioned large gear is profiled with an outwardly convex boss body, a small support bearing is installed in the boss body to rotatably support the middle shaft, a motor end cover is arranged between the large gear and the toothed disc to protect the large gear, the dynamic seat plate, and the static seat, the motor end cover is cooperated with the assembly disc cover, and an asbestos pad is press-fitted between the motor end cover and the assembly disc.

[0009] The boss body of the above-mentioned large gear is externally sleeved with a large support bearing to rotatably support the motor end cover; a middle bearing is installed on the middle shaft at the left end of the induction shaft sleeve.

[0010] The centers of the above-mentioned sending end coil and receiving end coil are aligned, and the sending end coil and the receiving end coil are connected by non-contact electromagnetic induction signal transmission.

[0011] The above-mentioned magnetic ring is provided with 18 to 36 pairs of magnetic poles, and the receiving end PCB is provided with a Hall element cooperated with the magnetic ring to detect the rotational speed of the middle shaft.

[0012] The right side of the above-mentioned sending end coil and the left side of the receiving end coil are each provided with a magnetic shielding sheet to shield external electromagnetic signal interference.

[0013] The above-mentioned middle shaft is provided with a first snap spring to prevent the left bearing from axially moving and a second snap spring to prevent the middle bearing (Z3) and the induction shaft sleeve from axially moving.

[0014] The left end of the above-mentioned middle shaft is sleeved with a left oil seal to seal the left end port of the middle pipe, and the right end of the middle shaft is provided with a right oil seal between the five claws.

[0015] The first wave spring washer is matched with the first wave spring washer between the first snap spring and the left bearing shaft, and the second wave spring washer is matched with the second wave spring washer between the small supporting bearing and the ratchet wheel.

[0016] The middle shaft is formed with a square head and an internally threaded hole at two ends.

[0017] Compared with the prior art, the induction shaft sleeve of the utility model is connected through the spline tooth sleeve transmission, the induction shaft sleeve is further fixedly installed with a movable seat plate capable of rotating synchronously with the induction shaft sleeve, the movable seat plate is fixedly installed with a movable seat, and the movable seat is installed with a sending end PCB, a sending end coil and a magnetic ring. The static seat is fixedly installed on the assembly disc formed at the right end of the middle pipe, and the static seat is fixedly installed with a receiving end PCB and a receiving end coil. The sending end coil and the receiving end coil utilize the electromagnetic induction principle to non-contact signal transmission, which can greatly reduce the mechanical wear between components, improve the service life of the product, and ensure the continuity and accuracy of signal transmission at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is the sectional view of the utility model;

[0019] Figure 2 is the utility model's explosion view;

[0020] Figure 3 is one of the utility model's three-dimensional structure schematic view;

[0021] Figure 4 is another three-dimensional structure schematic view of the utility model from another perspective. DETAILED DESCRIPTION

[0022] The embodiments of the utility model are further described in detail below with reference to the drawings.

[0023] Figures 1 to 4 is the structure and assembly schematic view of the utility model.

[0024] The reference signs in the drawings are as follows: the first wave spring washer B1, the second wave spring washer B2, the asbestos washer D, the left oil seal F1, the right oil seal F2, the first snap spring K1, the second snap spring K2, the left bearing Z1, the right bearing Z2, the middle bearing Z3, the motor main body 1, the middle pipe 11, the assembly disc 12, the motor end cover 13, the motor output end gear 14, the middle shaft 2, the spline tooth 21, the square head 22, the internally threaded hole 23, the induction shaft sleeve 3, the movable seat plate 4, the movable seat 41, the sending end PCB 42, the sending end coil 43, the magnetic ring 44, the static seat 5, the receiving end PCB 51, the receiving end coil 52, the ratchet wheel 6, the large gear 7, the small supporting bearing 71, the large supporting bearing 72, the magnetic separation sheet 8, the toothed disc 9 and the five claws 91.

[0025] As Figures 1 to 4The utility model discloses a torque sensor for middle -position motor based on the principle of should piece, this torque sensor includes motor main body 1, the axle 2 of middle, induction axle sleeve 3, dynamic seat plate 4, static seat 5 and left bearing Z1 and right bearing Z2. Figure 2It can be seen that the bottom of the motor body 1 is provided with a middle tube 11 which is axially through, and a coaxial assembly disc 12 is formed at the right end of the middle tube 11. The middle shaft 2 is rotatably arranged in the middle tube 11, and the left bearing Z1 is sleeved on the left end of the middle shaft 2 and is in rotatable supporting cooperation with the middle tube 11. The two ends of the middle shaft 2 are both formed with a square head 22 and an internally threaded hole 23, the square head 22 can be rotatably sleeved with the crank of the bicycle, and the internally threaded hole 23 can be installed with a bolt to lock the crank. The middle part of the middle shaft 2 is formed with a spline tooth 21, the left end of the induction shaft sleeve 3 is formed with a spline groove matched with the spline tooth 21, the induction shaft sleeve 3 is sleeved on the middle shaft 2 and is connected in transmission cooperation by the matching of the spline tooth 21 and the spline groove. The middle part of the induction shaft sleeve 3 is formed with a bearing mounting position, the right bearing Z2 is positioned and sleeved on the bearing mounting position formed on the induction shaft sleeve 3 and is in rotatable supporting cooperation with the right end of the middle tube 11. The movable seat plate 4 of the utility model is fixedly sleeved on the induction shaft sleeve 3 and is located at the right side of the right bearing Z2, and the right side of the movable seat plate 4 is provided with a ratchet wheel 6. The outer circumferential surface of the right end of the induction shaft sleeve 3 is also formed with a spline tooth, and the ratchet wheel 6 is also sleeved on the induction shaft sleeve 3 and is connected in transmission cooperation with the induction shaft sleeve 3 through the spline tooth. The outer ring of the ratchet wheel 6 is provided with a large gear 7, and the right side surface of the large gear 7 is fixedly press-fitted with a toothed disc 9 through five claws 91. The periphery of the large gear 7 is formed with teeth, and the teeth are engaged with the motor output end gear 14 of the motor body 1. The outer circumferential surface of the induction shaft sleeve 3 is equally radially pasted with 4 to 6 groups of strain gauges, when the cyclist transmits the torsional moment to the middle shaft 2 by pedaling the crank, the middle shaft 2 transmits the received torsional moment to the toothed disc 9 through the induction shaft sleeve 3, the ratchet wheel 6 and the large gear 7. The induction shaft sleeve 3 is slightly deformed under stress, and the strain gauges arranged on the induction shaft sleeve 3 can convert the slight deformation into electrical signals. The utility model is fixedly installed with a movable seat 41 on the left end surface of the movable seat plate 4, and the movable seat 41 is fixedly installed with a sending end PCB 42, a sending end coil 43 and a magnetic ring 44. The electrical signals converted by the strain gauges are transmitted to the sending end PCB 42 through a cable, and the sending end PCB 42 transmits the received electrical signals to the sending end coil 43. The utility model is fixedly installed with a static seat 5 on the assembly disc 12 formed at the right end of the middle tube 11, and the static seat 5 is fixedly installed with a receiving end PCB 51 and a receiving end coil 52. The receiving end coil 52 is arranged in non-contact correspondence with the sending end coil 43, the centers of the two are aligned, and the sending end coil 43 and the receiving end coil 52 utilize the electromagnetic induction principle and signal transmission cooperation. The advantage of utilizing the electromagnetic induction principle for signal transmission is that it can reduce mechanical wear while ensuring continuous, real-time and accurate signals. The receiving end coil 52 transmits the received induction electrical signals to the receiving end PCB 51, and the receiving end PCB 51 outputs the received electrical signals after operation processing.

[0026] In the embodiment Figure 1 and Figure 2As shown, the right end face of the gear wheel 7 is formed with a convex boss body, a small supporting bearing 71 is installed in the boss body and matched with the rotating support of the middle shaft 2, a motor end cover 13 is arranged between the gear wheel 7 and the toothed disc 9, the motor end cover 13 is matched with the cover assembly of the assembly disc 12, and the gear wheel 7, the moving seat plate 4 and the static seat 5 can be protected by the cover sleeve. In order to ensure the sealing performance, the motor end cover 13 and the assembly disc 12 are further pressed with an asbestos pad D.

[0027] In the embodiment, the boss body of the gear wheel 7 is sleeved with a large supporting bearing 72, and the outer ring of the large supporting bearing 72 is matched with the bearing hole of the motor end cover 13 in the rotating support. In order to improve the stability of the rotation of the middle shaft 2, a middle bearing Z3 is installed on the middle shaft 2 and located at the left end of the induction shaft sleeve 3.

[0028] In the embodiment, the magnetic ring 44 is provided with 18 to 36 pairs of magnetic poles, and the receiving end PCB 51 is provided with a Hall element matched with the magnetic ring 44 and used for detecting the rotating speed of the middle shaft 2.

[0029] In the embodiment, the right side of the sending end coil 43 and the left side of the receiving end coil 52 are each provided with a magnetic shielding sheet 8. According to the Faraday cage principle, the magnetic shielding sheet 8 can shield external electromagnetic signal interference, so as to ensure the accuracy of signal transmission.

[0030] In the embodiment, the middle shaft 2 is provided with a first clamping spring K1 for preventing the axial movement of the left bearing Z1 and a second clamping spring K2 for preventing the axial movement of the middle bearing Z3 and the induction shaft sleeve 3.

[0031] The left end of the middle shaft 2 is sleeved with a left oil seal F1 matched with the left end sealing of the middle pipe 11, and the right end of the middle shaft 2 is provided with a right oil seal F2 between the five claws 91.

[0032] The first clamping spring K1 is matched with a first corrugated gasket B1 between the shaft of the left bearing Z1, and the small supporting bearing 71 is matched with a second corrugated gasket B2 between the ratchet wheel 6. The corrugated gasket can eliminate the tolerance gap between the two components.

[0033] The strain gauge measures the torsion force received by the middle shaft, and the torque signal obtained by the measurement is continuous, real-time and accurate.

[0034] The best embodiment of the utility model has been illustrated, and various changes or modifications made by those skilled in the art will not deviate from the scope of the utility model.

Claims

1. A mid-mounted motor torque sensor, comprising a motor body (1), a central shaft (2), a sensing bushing (3), a moving base plate (4), a stationary base (5), and a left bearing (Z1) and a right bearing (Z2); the bottom of the motor body (1) is provided with a central tube (11), and strain gauges are attached to the surface of the sensing bushing (3); characterized in that: The central shaft (2) is rotatably supported by the left bearing (Z1) and passes through the central tube (11). The central shaft (2) has a spline tooth (21) formed in the middle. The sensing bushing (3) is connected to the central shaft (2) through the spline tooth (21). The right bearing (Z2) is positioned and fitted in the middle of the sensing bushing (3) and rotatably supports the right end of the central tube (11). The moving base plate (4) is fixedly fitted on the sensing bushing (3) and located to the right of the right bearing (Z2). The right side of the moving base plate is provided with a transmission connection with the sensing bushing (3). The ratchet (6) is fitted with a large gear (7) on its outer ring. A toothed plate (9) is pressed onto the right side of the large gear (7) by a five-jaw (91). A moving seat (41) is fixedly installed on the left end face of the moving seat plate (4). A transmitting PCB (42), a transmitting coil (43), and a magnetic ring (44) are fixedly installed on the moving seat (41). A stationary seat (5) is fixedly installed on the assembly plate (12) formed on the right end of the middle tube (11). A receiving PCB (51) and a receiving coil (52) are fixedly installed on the stationary seat (5).

2. The mid-mounted motor torque sensor according to claim 1, characterized in that: The right end face of the large gear (7) is formed with an outwardly protruding boss body. A small support bearing (71) that mates with the rotational support of the central shaft (2) is installed in the boss body. A motor end cover (13) is provided between the large gear (7) and the gear plate (9) to protect the large gear (7), the moving seat plate (4) and the stationary seat (5). The motor end cover (13) is fitted with the mounting plate (12), and an asbestos pad (D) is pressed between the motor end cover (13) and the mounting plate (12).

3. A mid-mounted motor torque sensor according to claim 2, characterized in that: The large gear (7) has a large support bearing (72) on its boss body for rotating and cooperating with the motor end cover (13); the central shaft (2) has a central bearing (Z3) installed at the left end of the sensing shaft sleeve (3).

4. A mid-mounted motor torque sensor according to claim 3, characterized in that: The centers of the transmitting coil (43) and the receiving coil (52) are aligned, and the transmitting coil (43) and the receiving coil (52) are connected in a non-contact manner for electromagnetic induction signal transmission.

5. A mid-mounted motor torque sensor according to claim 4, characterized in that: The magnetic ring (44) is provided with 18 to 36 pairs of magnetic poles, and the receiving end PCB (51) is provided with a Hall element that cooperates with the magnetic ring (44) to detect the rotation speed of the central shaft (2).

6. A mid-mounted motor torque sensor according to claim 5, characterized in that: A magnetic shielding sheet (8) for shielding external electromagnetic signal interference is provided on the right side of the transmitting coil (43) and the left side of the receiving coil (52).

7. A mid-mounted motor torque sensor according to claim 6, characterized in that: The central shaft (2) is provided with a first retaining ring (K1) to prevent the left bearing (Z1) from axially moving and a second retaining ring (K2) to prevent the central bearing (Z3) and the sensing bushing (3) from axially moving.

8. A mid-mounted motor torque sensor according to claim 7, characterized in that: The left end of the central shaft (2) is fitted with a left oil seal (F1) that is compatible with the left port seal of the central tube (11), and the right end of the central shaft (2) is provided with a right oil seal (F2) between the five claws (91).

9. A mid-mounted motor torque sensor according to claim 8, characterized in that: The first retaining ring (K1) and the left bearing (Z1) are fitted with a first corrugated washer (B1), and the small support bearing (71) and the ratchet (6) are fitted with a second corrugated washer (B2).

10. A mid-mounted motor torque sensor according to claim 9, characterized in that: The two ends of the central shaft (2) are formed with square heads (22) and internal threaded holes (23).

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