A worm gear deceleration type middle-embedded motor and moped

Abstract

The application discloses a worm-gear deceleration type middle-arranged motor, which comprises a motor assembly, a deceleration assembly, a middle shaft, a detection assembly, a shell and a power output part; the deceleration assembly comprises a worm connected with the motor assembly and a worm gear coaxially arranged with the middle shaft; the detection assembly comprises a transmission sleeve and a torque detection device; the transmission sleeve is sleeved on the middle shaft and connected with the power output part; at least a part of the transmission sleeve can be deformed due to a torsional torque; the shell comprises a closed shell for accommodating the deceleration assembly; the closed shell is filled with lubricant; the shell further comprises a cover fixed at one end of the closed shell; the torque detection device is installed in the cover; the transmission sleeve penetrates through the cover; one end of the transmission sleeve extends into the closed shell; a first one-way clutch is arranged between the worm gear and the transmission sleeve; the other end of the transmission sleeve penetrates out of the cover and is connected with the power output part. The middle-arranged motor has reasonable internal layout and is convenient to install.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of moped, in particular to a worm gear deceleration type middle motor and moped. BACKGROUND

[0002] The middle motor is the core component of the electric moped, and the existing middle motor generally decelerates the rotational speed output by the rotor based on the planetary gear reducer, harmonic reducer and other reduction mechanisms. In terms of layout, the rotor is generally installed in a biased or coaxial manner with the middle shaft.

[0003] In the prior art, patents CN206664847U, CN106972693A (and its same-day application for a utility model) and CN109292034A (and its same-day application for a utility model) all involve middle motors that use worm gear mechanisms to decelerate the rotational speed output by the motor. These middle motors are suitable for use on electric vehicles. Although patent CN109292034A has a pedal, it does not have a torque feedback device and cannot adaptively assist.

[0004] In other types of middle motors, some have torque feedback devices, such as the middle motor shown in CN115149719A. Due to the relatively simple lubrication conditions of the reduction mechanism, the reduction mechanism and the torque feedback device are installed in the same cavity, and the motor housing is relatively traditional. For worm gear mechanisms, the lubrication conditions are relatively high, so the internal layout of the motor needs to be redesigned to ensure the rationality of the cavity design and the convenience of installation, which is the main technical problem. In addition, the structure of the torque feedback device in patent CN115149719A is complex, making production and installation difficult, which is the second technical problem. SUMMARY

[0005] The present application provides a worm gear deceleration type middle motor and moped with a reasonable internal layout and convenient installation to overcome the deficiencies in the prior art.

[0006] Technical solution: To achieve the above-mentioned purpose, the worm gear deceleration type middle motor of the present application comprises a motor assembly, a reduction assembly, a middle shaft, a detection assembly, a housing and a power output; the reduction assembly comprises a worm connected to the motor assembly and a worm gear coaxially arranged with the middle shaft; the detection assembly comprises a transmission sleeve and a torque detection device, the transmission sleeve is sleeved on the middle shaft and connected to the power output, at least a part of the transmission sleeve can be deformed due to the torsional torque received;

[0007] The housing comprises a sealed housing for accommodating the reduction assembly, and the sealed housing is filled with a lubricant;

[0008] The housing further comprises a cover fixed at one end of the closed housing, and the torque detection device is installed in the cover;

[0009] The transmission sleeve passes through the closed housing, and one end of the transmission sleeve extends into the cover; a first one-way clutch is arranged between the worm gear and the transmission sleeve; the other end of the transmission sleeve is exposed outside the closed housing and connected to the power output.

[0010] Further, the transmission sleeve passes through the entire closed housing, and a first bearing and a first oil seal are respectively arranged between the two sides of the closed housing and the transmission sleeve.

[0011] Further, the worm is connected with a shaft body, and the shaft body extends out of the closed housing; a second bearing and a second oil seal are arranged between the shaft body and the closed housing.

[0012] Further, the transmission sleeve is composed of a rigid sleeve and a torque deformation sleeve, and the two are connected through spline; the rigid sleeve passes through the entire closed housing, and the first bearing and the first oil seal are respectively arranged between the two sides of the closed housing and the transmission sleeve, and the third bearing is respectively arranged between the two ends of the torque deformation sleeve and the two ends of the cover; the cover and the power output are respectively arranged on the two sides of the closed housing; the power output is fixed at the end of the rigid sleeve.

[0013] Further, the reduction ratio of the speed reduction assembly is not greater than 45; the width of the closed housing in the axial direction of the middle shaft is not greater than 100 mm.

[0014] Further, a second one-way clutch is installed between the transmission sleeve and the middle shaft, and the second one-way clutch is arranged at the end of the torque deformation sleeve away from the rigid sleeve.

[0015] Further, the torque detection device comprises two parallel circuit boards, namely a first circuit board and a second circuit board, which are respectively fixed on the transmission sleeve and in the cover; the torque detection device further comprises a strain gauge fixed on the transmission sleeve, and the strain gauge is connected to the first circuit board; the first circuit board and the second circuit board are respectively provided with a first coil and a second coil on the end face facing the other circuit board.

[0016] Further, the number of strain gauges is two, and the two are installed on the transmission sleeve with an interval of 180°; the first circuit board has two half-bridge units, and the two half-bridge units are respectively connected to the two strain gauges.

[0017] The first circuit board middle part has a through hole, and two half-bridge units are connected by a connecting line along the edge of the through hole to form a full-bridge.

[0018] A moped comprises a frame, a front wheel assembly and a rear wheel are respectively installed on the front and rear sides of the frame, a worm gear reduction type middle motor is installed on the middle part of the frame, and a power supply is connected to the worm gear reduction type middle motor.

[0019] The frame has at least one pipe connected to the worm gear reduction type middle motor, and the axial direction of the motor assembly is consistent with the extension direction of the end of the pipe.

[0020] Further, the power supply is installed in the pipe.

[0021] Advantages: the worm gear reduction type middle motor and the moped have the following advantages:

[0022] (1) By setting the closed housing accommodating the worm gear mechanism and the cover accommodating the torque detection device, dry and wet separation inside the housing can be achieved, on the one hand, the worm gear mechanism and the first one-way clutch can run under the condition of sufficient lubrication, on the other hand, the torque detection device can run in a dry and dust-free environment, the cover is closed by the outer wall of the closed housing, which can improve the compactness of the structure.

[0023] (2) The torque detection device is designed reasonably, simple in structure, easy to install, and can reduce the manufacturing cost and assembly difficulty. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a first sectional view of the worm gear reduction type middle motor.

[0025] Figure 2 It is a second sectional view of the worm gear reduction type middle motor.

[0026] Figure 3 It is a structure diagram of the first coil on the first circuit board.

[0027] Figure 4 It is a bridge structure schematic diagram of the half-bridge unit on the first circuit board.

[0028] Figure 5 It is a structure schematic diagram of the moped.

[0029] In the figure: 1-motor assembly; 11-motor housing; 12-stator; 13-rotor; 2-reduction assembly; 21-worm; 21a-shaft; 22-worm gear; 3-middle shaft; 4-detection assembly; 41-transmission sleeve; 41a-rigid sleeve; 41b-torque deformation sleeve; 42-torque detection device; 43-cadence sensor; 421-first circuit board; 422-second circuit board; 423-strain gauge; 424-half-bridge unit; 425-connecting line; 5-housing; 51-sealed housing; 51a-mounting surface; 52-cover; 6-power output member; 71-first bearing; 72-first oil seal; 73-second bearing; 74-second oil seal; 75-third bearing; 8-first one-way clutch; 9-second one-way clutch; 10-frame; 101-pipe fitting; 20-front wheel assembly; 30-rear wheel; 40-power supply; 50-needle roller bearing. DETAILED DESCRIPTION

[0030] The present invention will be further described below with reference to the accompanying drawings.

[0031] like Figures 1-2 The worm gear reduction mid-mounted motor shown includes a motor assembly 1, a reduction assembly 2, a central shaft 3, a detection assembly 4, a housing 5, and a power output member 6; both ends of the central shaft 3 are connected to pedal cranks; the reduction assembly 2 includes a worm 21 connected to the motor assembly 1 and a worm wheel 22 coaxially arranged with the central shaft 3; the detection assembly 4 includes a transmission sleeve 41, a torque detection device 42, and a cadence sensor 43, and the torque detection device 42 and the cadence sensor 43 are all installed around the transmission sleeve 41 without increasing the axial length of the motor; the transmission sleeve 41 is sleeved on the central shaft 3 and connected to the power output member 6, and at least a portion of the transmission sleeve 41 can be deformed due to the torsional torque received; a needle bearing 50 can be provided between the transmission sleeve 41 and the central shaft 3 to maintain the smoothness and coaxiality of the relative rotation between the two;

[0032] The outer shell 5 includes a sealed shell 51 for accommodating the reduction assembly 2, and the sealed shell 51 is filled with lubricant; the outer shell 5 also includes a cover shell 52 fixed at one end of the sealed shell 51, and the torque detection device 42 is installed in the cover shell 52; the transmission sleeve 41 passes through the sealed shell 51, and one end of the transmission sleeve 41 extends into the cover shell 52; a first one-way clutch 8 is provided between the worm gear 22 and the transmission sleeve 41; the other end of the transmission sleeve 41 is exposed from the sealed shell 51 and is connected to the power output member 6, where the power output member 6 is a sprocket.

[0033] In the structure, the reduction assembly 2 is based on a worm and gear mechanism, the worm and gear mechanism has a large reduction ratio, is thin as a whole, and occupies a small axial space, so that the thickness of the middle motor can be effectively reduced and the compactness of the structure is improved.

[0034] The structure of the housing 5 is reasonable, the closed shell 51 accommodating the worm and gear mechanism and the cover 52 accommodating the torque detection device 42 are arranged, the dry and wet separation of the inside of the housing 5 can be realized, on one hand, the worm and gear mechanism and the first one-way clutch 8 can operate under the condition of sufficient lubrication, on the other hand, the torque detection device 42 can operate in a dry and dust-free environment, the cover 52 is closed by the outer wall of the closed shell 51, and the compactness of the structure can be improved.

[0035] Preferably, the transmission sleeve 41 passes through the entire closed shell 51, and the first bearing 71 and the first oil seal 72 are arranged between the two sides of the closed shell 51 and the transmission sleeve 41, respectively.

[0036] In the embodiment, the transmission sleeve 41 is composed of a rigid sleeve 41a and a torque deformation sleeve 41b, and the two are connected by spline connection, wherein the rigid sleeve 41a passes through the entire closed shell 51, the first bearing 71 and the first oil seal 72 are arranged between the two sides of the closed shell 51 and the transmission sleeve 41, respectively, the third bearing 75 is arranged between the two ends of the torque deformation sleeve 41b and the two ends of the cover 52, respectively, the cover 52 and the power output 6 are arranged on the two sides of the closed shell 51, respectively, and the power output 6 is fixed to the end of the rigid sleeve 41a, that is, the power output by the worm 22 is directly transmitted to the power output 6 through the rigid sleeve 41a. In this way, since the rigid sleeve 41a has rigidity, the airtightness of the closed shell 51 can be ensured, the torque deformation sleeve 41b can be deformed to enable the torque detection device to obtain torque data according to the deformation amount of the torque deformation sleeve 41b, and the stability of both the rigid sleeve 41a and the torque deformation sleeve 41b can be ensured.

[0037] Preferably, the shaft 21a is connected to the worm 21, the worm 21 and the shaft 21a can be integrally formed or separately formed and assembled together, and the shaft 21a extends out of the closed shell 51; the second bearing 73 and the second oil seal 74 are arranged between the shaft 21a and the closed shell 51.

[0038] Preferably, the mounting surface 51a is formed on the closed shell 51, and the open end of the cover 52 is buckled and fixed on the mounting surface 51a.

[0039] Preferably, the motor assembly 1 comprises a motor housing 11 fixed on the closed shell 51, and further comprises a stator 12 and a rotor 13; the rotor 13 is fixed on the shaft body 21a, and specifically, the worm 21 is formed with the shaft body which extends into the motor housing 11 and is fixedly connected with the rotor 13.

[0040] Preferably, a second one-way clutch 9 is arranged between the transmission sleeve 41 and the middle shaft 3, and the second one-way clutch 9 is arranged on the torque deformation sleeve 41b away from the rigid sleeve 41a. That is, the second one-way clutch 9 and the power output 6 are respectively arranged at two ends of the transmission sleeve 41, and the power provided by the middle shaft 3 is transmitted to the power output 6 via the torque deformation sleeve 41b and the rigid sleeve 41a.

[0041] The torque detection device 42 comprises two parallel circuit boards, i.e. a first circuit board 421 and a second circuit board 422, and the positions of the two circuit boards can be exchanged, and the two circuit boards are respectively fixed on the transmission sleeve 41 and in the shell 52; the torque detection device 42 further comprises a strain gauge 423 fixed on the torque deformation sleeve 41b, and the strain gauge 423 is connected with the first circuit board 421; a step frequency sensor 43 is connected with the second circuit board 422, and the first circuit board 421 and the second circuit board 422 are respectively provided with a first coil and a second coil on the end faces facing each other. Figure 3 As shown in the figure, the first coil is a vortex conductive line printed on one end face of the first circuit board 421, and the other end face of the first circuit board 421 is provided with a first circuit connected with the first coil, so as to avoid electromagnetic interference between the first circuit and the first coil; similarly, the second coil is a vortex conductive line printed on one end face of the second circuit board 422, and the other end face of the second circuit board 422 is provided with a second circuit connected with the second coil. The second circuit is connected with a power supply and a control system, and the second circuit can generate an alternating current on the second coil, so that the second coil generates an alternating magnetic field, and the first coil generates an alternating current through the principle of electromagnetic induction. The first circuit comprises a rectifier circuit for rectifying the alternating current, and the rectifier circuit supplies power to other parts of the first circuit. At the same time, the first circuit receives the electric signal generated by the strain gauge 423 to obtain torque data, and modulates the torque data to form an alternating magnetic field on the first coil. Through the principle of electromagnetic induction, the second coil receives the torque data, and the second circuit outputs the received torque data to the control system, and the control system dynamically adjusts the operating power of the motor assembly 1 according to the torque data.

[0042] Preferably, the number of strain gauges 423 is two, and the two strain gauges are installed on the transmission sleeve 41 with an interval of 180°. Figure 4As shown, the first circuit board 421 has two half-bridge units 424, and the two half-bridge units 424 are respectively connected to the two strain gauges 423; the first circuit board 421 has a through hole in the middle, and the two half-bridge units 424 are connected by a connecting line 425 along the edge of the through hole to form a full-bridge, and the connecting line 425 and the first coil are arranged on the two end surfaces of the first circuit board 421, so that the connecting line 425 and the first coil can be effectively staggered to avoid signal interference therebetween.

[0043] The strain gauge 423 is mounted on the torque deformation sleeve 41b close to one end of the rigid sleeve 41a, so that when the user transmits power to the power output member 6 through the pedal, the transmission sleeve 41 can be fully deformed, and the deformation calculated by the strain gauge 423 can reflect the size of the user's force, and when the motor assembly 1 intervenes through the speed reduction assembly 2, the power is directly transmitted to the power output member 6.

[0044] With the above structure, the moped with the above-mentioned center motor can realize the following three modes:

[0045] The first mode is pure human power mode, the motor assembly 1 does not operate, the worm gear is fixed, the middle shaft 3 rotates in the positive direction under the action of human power, at this time, the second one-way clutch 9 plays a role of connecting the torque on the middle shaft 3 to the transmission sleeve 41, and the power transmitted by the second one-way clutch 9 is transmitted to the power output member 6 in sequence through the torque deformation sleeve 41b and the rigid sleeve 41a to drive the moped to move. At this time, the first one-way clutch 8 does not play a connecting role.

[0046] The second mode is motor-assisted mode, on the one hand, human power makes the middle shaft 3 rotate in the positive direction, and the second one-way clutch 9 plays a role of connecting the torque on the middle shaft 3 to the torque deformation sleeve 41b; on the other hand, the motor assembly 1 operates, the first one-way clutch 8 plays a role of connecting, and the torque is transmitted to the rigid sleeve 41a through the worm gear mechanism, the combined force of human power and the motor assembly 1 makes the transmission sleeve 41 rotate, and the transmission sleeve 41 transmits power to the power output member 6. In this case, the torque detection device 42 obtains torque data according to the deformation of the torque deformation sleeve 41b, and the control system of the moped dynamically adjusts the operating power of the motor assembly 1 according to the torque data to distribute the appropriate assist torque, thereby reducing the difficulty of riding for the user.

[0047] The third mode is pure electric mode, the motor assembly 1 operates, the first one-way clutch 8 plays a role of connecting, and the torque is transmitted to the transmission sleeve 41 through the worm gear mechanism, and the transmission sleeve 41 transmits power to the power output member 6. In this case, the user can make the middle shaft 3 not rotate, reverse or rotate slowly in the positive direction, and since the rotation speed of the transmission sleeve 41 is faster than that of the middle shaft 3, the second one-way clutch 9 does not play a connecting role.

[0048] Preferably, the reduction ratio of the reduction assembly 2 is not greater than 45; and the width of the sealed housing 51 in the axial direction of the central shaft 3 is not greater than 100 mm.

[0049] The assembly sequence of the above-mentioned mid-mounted motor is as follows: step s1, assemble the rigid sleeve 41a, the first one-way clutch 8, the worm gear 22, the worm 21, and the motor part 1 together; step s2, install the first circuit board 421 and the strain gauge 423 on the torque deformation sleeve 41b, and establish a connection between the first circuit board 421 and the strain gauge 423; step s3, install the torque deformation sleeve 41b, the second circuit board 422 and the cadence sensor 43 into the cover shell 52; step s4, install the central axis 3 to the rigid sleeve 41a or the torque deformation sleeve 41b; step s5, install the cover shell 52 on the sealed shell 51, and establish a connection between the rigid sleeve 41a and the torque deformation sleeve 41b, buckle the open end of the cover shell 52 onto the mounting surface 51a, and fix the cover shell 52 relative to the mounting surface 51a with screws.

[0050] A power-assisted vehicle, such as Figure 5 As shown, it includes a frame 10, with a front wheel assembly 20 and a rear wheel 30 mounted on the front and rear sides of the frame 10 respectively; the above-mentioned worm gear reduction mid-mounted motor is mounted in the middle of the frame 10; and also includes a power supply 40 connected to the worm gear reduction mid-mounted motor;

[0051] The vehicle frame 10 has at least one pipe 101 connected to the worm gear reduction mid-mounted motor, and the axial direction of the motor assembly 1 is consistent with the extension direction of the end of one of the pipes 101. Here, the motor assembly 1 can be built into the end of the pipe 101, or the motor housing 11 of the motor assembly 1 can be fixed to the end of the pipe 101 and continue to extend along the extension direction of the end of the pipe 101, or the pipe 101 can constitute a part of the motor housing 11. Figure 2 As shown, the installation angle of the axis of the rotor 13 of the motor assembly 1 relative to the central shaft 3 is between 0-180°. Preferably, the motor assembly 1 is located on the upper side of the plane passing through the center line of the central shaft 3.

[0052] Preferably, the power supply 40 is installed in the pipe 101 .

[0053] By adopting the above structure, the motor assembly 1 and the power supply 40 can be effectively hidden, making the structure of the power-assisted bicycle streamlined. Compared with a bicycle without power assistance, it appears to have fewer redundant parts. Integrating the motor assembly 1 and the power supply 40 into the frame 10 can also reduce the external mounting structure and reduce the weight of the power-assisted bicycle.

[0054] The above merely describes the preferred embodiments of the present application, and it should be pointed out that those skilled in the art can make several improvements and refinements without departing from the principles of the present application, and these improvements and refinements should also be considered as the protection scope of the present application.

Claims

1. A worm-reduction type middle-mounted motor, comprising a motor assembly (1), a reduction assembly (2), a middle shaft (3), a detection assembly (4), a housing (5) and a power output (6); the reduction assembly (2) comprises a worm (21) connected to the motor assembly (1) and a worm gear (22) coaxially arranged with the middle shaft (3); the detection assembly (4) comprises a transmission sleeve (41) and a torque detection device (42), the transmission sleeve (41) is sleeved on the middle shaft (3) and connected to the power output (6), at least a part of the transmission sleeve (41) can be deformed due to the torsional torque; characterized in that: the housing (5) comprises a closed housing (51) for accommodating the reduction assembly (2), the closed housing (51) is filled with lubricant; the housing (5) further comprises a cover (52) fixed to one end of the closed housing (51), the torque detection device (42) is installed in the cover (52); the transmission sleeve (41) passes through the closed housing (51), and one end of the transmission sleeve (41) extends into the cover (52); a first one-way clutch (8) is arranged between the worm gear (22) and the transmission sleeve (41); the other end of the transmission sleeve (41) is exposed from the closed housing (51) and connected to the power output (6); first bearings (71) and first oil seals (72) are respectively arranged between the two sides of the closed housing (51) and the transmission sleeve (41); the transmission sleeve (41) is composed of a rigid sleeve (41a) and a torque deformation sleeve (41b), and the two are connected by spline; the rigid sleeve (41a) passes through the entire closed housing (51), the first bearings (71) and the first oil seals (72) are respectively arranged between the two sides of the closed housing (51) and the transmission sleeve (41), and the third bearings (75) are respectively arranged between the two ends of the torque deformation sleeve (41b) and the two ends of the cover (52); the cover (52) and the power output (6) are respectively arranged on the two sides of the closed housing (51); the power output (6) is fixed to the end of the rigid sleeve (41a); the torque detection device (42) comprises two parallel circuit boards, namely a first circuit board (421) and a second circuit board (422), which are respectively fixed on the transmission sleeve (41) and in the cover (52); the torque detection device (42) further comprises a strain gauge (423) fixed on the transmission sleeve (41), the strain gauge (423) is connected to the first circuit board (421); the first circuit board (421) and the second circuit board (422) are respectively provided with first coils and second coils on the end faces facing the other circuit board.

2. The worm-reduced central motor according to claim 1, characterized in that, The worm (21) is connected with a shaft body (21a) which extends out of the closed housing (51); the shaft body (21a) and the closed housing (51) are provided with a second bearing (73) and a second oil seal (74).

3. The worm-reduced central motor according to claim 2, characterized in that, The reduction ratio of the reduction assembly (2) is not greater than 45; the width of the closed housing (51) in the axial direction of the shaft (3) is not greater than 100 mm.

4. The worm-reduced central motor according to claim 1, wherein A second one-way clutch (9) is installed between the transmission sleeve (41) and the shaft (3), and the second one-way clutch (9) is arranged on the torque deformation sleeve (41b) away from the rigid sleeve (41a).

5. The worm-reduced central motor according to claim 1, wherein The number of strain gauges (423) is two, which are installed on the transmission sleeve (41) at intervals of 180°; the first circuit board (421) has two half-bridge units (424), and the two half-bridge units (424) are respectively connected to two strain gauges (423). The first circuit board (421) has a through hole in the middle, and the two half-bridge units (424) are connected by a connecting line (425) along the edge of the through hole to form a full-bridge.

6. A moped, characterized in that It comprises a frame (10), the front and rear sides of the frame (10) are respectively provided with a front wheel assembly (20) and a rear wheel (30); the middle part of the frame (10) is provided with the worm and gear reduction type middle motor according to any one of claims 1-5; further comprising a power supply (40) connected to the worm and gear reduction type middle motor; The frame (10) has at least one pipe (101) connected to the worm and gear reduction type middle motor, and the axial direction of the motor assembly (1) is consistent with the extension direction of the end of the pipe (101).

7. Scooter according to claim 6, characterized in that The power supply (40) is installed in the pipe (101).

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