Wheel hub motor with safety brake for wheelchair

Abstract

The present invention relates to a wheel hub motor for a wheelchair with a safety brake device, which is characterized in that: a plurality of stator support sleeve through holes are provided on the electromagnet moving piece, a stator support sleeve is passed through the stator support sleeve through hole, the electromagnet moving piece is slidably connected with the stator support sleeve, one end face of the stator support sleeve is in contact with the electromagnet seat, and the other end face of the stator support sleeve is in contact with the stator, the stator is fixed to the electromagnet seat by the stator fixing screw to form an inclusive space structure of the electromagnet moving piece and the friction plate, a friction plate is arranged between the electromagnet moving piece and the stator, and the outer circle of the friction plate is evenly distributed with connecting wings, and the connecting wings are embedded with the rotor grooves at the corresponding positions of the rotor to form an integrated structure. Beneficial effect: The support sleeve is built into the center hole of the friction plate, which maximizes the effective force arm size of the friction plate. Under the same pressure conditions, the same friction torque can be achieved with a smaller size, thereby achieving the purpose of lightweight and miniaturization.

Description

Technical Field

[0001] The invention belongs to the field of motors, and in particular relates to a wheel hub motor with a safety brake device for a wheelchair. Background Art

[0002] Considering the physical condition of people using wheelchairs, wheel hub motors for wheelchairs must have a braking function, and the braking resistance must meet certain conditions, such as being able to stop on a 9-10 degree slope. In order to meet the requirements of the braking function, existing wheel hub motors for wheelchairs generally use a wheel hub motor plus an electromagnetic brake device to achieve the braking function. At the same time, in order to meet the requirements of greater braking force, traditional designs all use larger electromagnetic brake devices. The traditional design concept is that the friction torque that can be generated by the friction plate is related to the pressure on the friction plate and the size of the friction surface arm of the friction plate. Therefore, in order to increase the friction torque, the existing wheel hub motor for wheelchairs must increase the overall outer diameter of the electromagnetic brake device. Although this design concept can increase the friction torque and meet the torque requirements, it leads to an increase in the size and weight of the wheelchair motor, which cannot meet the requirements of lightweight and miniaturization. At present, with the advent of an aging society, folding wheelchairs have become a development trend required by the market. In order to facilitate wheelchair users to move wheelchairs when changing cars or airplanes, the market urgently needs to promote miniaturized folding wheelchairs that are light in weight and as small as possible after folding. Since the wheel hub motors are installed on the left and right sides of the wheelchair, the wheel hub motors are too large and the axial dimension is too long. After folding, the axial distance between the two wheel hub motors must be very large, which cannot meet the requirements of miniaturization. The development of a wheel hub motor with a simple and compact structure and small size is an urgent issue to be solved in the industry to promote miniaturized and lightweight folding wheelchairs.

[0003] Inventive content

[0004] In order to overcome the deficiencies in the prior art, the present invention provides a wheel hub motor for a wheelchair with a safety brake device, so that the motor has a simple and compact structure, a small size and a light weight.

[0005] In order to achieve the above-mentioned purpose, the present invention is implemented through the following technical scheme: a wheel hub motor for a wheelchair with a safety brake device, including a stator, a rotor and a brake anti-slip mechanism mainly composed of an electromagnet seat, an electromagnet coil, an electromagnet movable plate, an electromagnet movable plate reset spring, a friction plate and a manual unlocking unit, wherein the center of the electromagnet seat is provided with a coil fixing boss, the electromagnet coil is sleeved on the coil fixing boss, and the coil fixing boss is provided with an electromagnet movable plate reset spring countersunk hole, wherein the electromagnet movable plate is provided with a plurality of stator support sleeve through holes, and the stator support sleeve through holes penetrate There is a stator support sleeve, the electromagnet moving piece is slidably connected to the stator support sleeve, one side end face of the stator support sleeve is in contact with the surface of the coil fixing boss of the electromagnet seat, and the other side end face of the stator support sleeve is in contact with the stator, and the stator is fixed to the electromagnet seat by a stator fixing screw to form an inclusive space structure of the electromagnet moving piece and the friction plate, a friction plate is arranged between the electromagnet moving piece and the stator, and the outer circle of the friction plate is evenly distributed with connecting wings, and the connecting wings are embedded with the rotor grooves at the corresponding positions of the rotor to form an integrated structure, the stator support sleeve is fixed on the surface of the coil fixing boss, and the stator support sleeve is completely contained in the inner circle of the friction plate.

[0006] The height of the stator support sleeve is the thickness of the electromagnet moving plate + the thickness of the friction plate + 0.1 mm to 0.2 mm.

[0007] The number of the stator support sleeve through holes and the stator support sleeve is 3-4, and they are arranged on concentric circles.

[0008] The electromagnet movable plate is provided with an unlocking screw through hole, the unlocking screw is screwed with the unlocking screw threaded hole on the electromagnet seat, the rear end of the unlocking screw is provided with a screwdriver transverse groove, and the fixed plate is provided with a manual unlocking process hole corresponding to the unlocking screw through hole position.

[0009] The friction plate is provided with a friction plate step facing the electromagnet moving plate, and the diameter of the friction plate step is smaller than the diameter of the electromagnet stator.

[0010] Beneficial effects: Compared with the prior art, the support sleeve is built into the center hole of the friction plate, which maximizes the effective force arm of the friction plate. Under the same pressure conditions, the same friction torque can be achieved with a smaller size, achieving the purpose of lightweight and miniaturization. The motor structure is simple and compact, small in size and light in weight, which helps to achieve lightweight and miniaturization of folding wheelchairs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a partial cross-sectional view of the structure of the present invention;

[0012] Figure 2 This is the left side view of the exploded view of the electromagnetic brake part;

[0013] Figure 3 This is the exploded right view of the electromagnetic brake part;

[0014] Figure 4 It is a three-dimensional cross-sectional view of the electromagnetic brake part;

[0015] Figure 5 This is a partial exploded view of the electromagnetic brake part.

[0016] In the figure: 1, main shaft, 2, stator, 3, rotor, 3-1, rotor groove, 4, rotor support bearing, 5, electromagnet seat, 5-1, unlocking screw threaded hole, 5-2, electromagnet movable plate reset spring countersink, 5-3, threaded hole, 5-4, coil fixing boss, 5-5, ball ejection spring countersink, 6, electromagnet coil, 7, electromagnet movable plate, 7-1, unlocking screw through hole, 7-2, stator support sleeve through hole, 8, friction plate, 8-1, connecting wing, 8-2, friction plate stepped platform, 9, stator, 9-1, manual unlocking process hole, 10, stator support sleeve, 11, stator fixing screw, 12, unlocking screw, 13, electromagnet movable plate reset spring, 14, end cover, 15, end cover support bearing, 16, wheel hub, 17, positioning ball, 18, ball ejection spring, 19, unlocking signal switch, 20, protective cover, 21, unlocking handle. DETAILED DESCRIPTION

[0017] The following is a detailed description of the specific implementation methods provided according to the present invention in combination with the preferred embodiments:

[0018] As shown in the accompanying drawings for details, this embodiment discloses a wheel hub motor for a wheelchair with a safety brake device, including a main shaft 1, a stator 2, a rotor 3, a rotor support bearing 4, an end cover 14, an end cover support bearing 15, a wheel hub 16, a tire provided outside the wheel hub, and an electromagnetic brake structure mainly composed of an electromagnet seat 5, an electromagnet coil 6, an electromagnet movable plate 7, an electromagnet movable plate return spring 13, a friction plate 8, and a stator 9, and also includes a manual unlocking unit and together with the electromagnetic brake structure constitutes a brake anti-slip mechanism. The manual unlocking unit includes an unlocking screw 12 and an unlocking handle 21. A circular hole is provided on the electromagnet movable plate, i.e., an unlocking screw through hole 7-1. An unlocking screw threaded hole 5-1 is provided on the electromagnet seat. After the unlocking screw passes through the circular hole, the middle section of the unlocking screw thread is screwed with the unlocking screw threaded hole. The front end of the unlocking screw is fixedly connected to the unlocking handle. The unlocking handle drives the unlocking screw to rotate clockwise or counterclockwise. At the same time, the unlocking screw moves axially forward and backward through its thread pitch. The unlocking screw drives the electromagnet movable plate and the friction plate to move axially forward and backward synchronously. Reset spring countersunk holes 5-2 are symmetrically provided on both sides of the unlocking screw threaded hole. The reset spring countersunk holes are built with electromagnet movable plate reset springs 13. A protective cover 20 is provided at the outer end of the anti-slip mechanism. A positioning ball 17 is provided between the top of the ejection spring and the inner side surface of the front end of the unlocking handle. A ball ejection spring countersunk hole 5-5 is provided on the electromagnet seat. A ball ejection spring countersunk hole is built with a ball ejection spring 18. An unlocking signal switch 19 is fixedly connected to the electromagnet seat.

[0019] The preferred improvement of this embodiment is a wheel hub motor for a wheelchair with a safety brake device, comprising a stator, a rotor and a brake anti-slip mechanism mainly composed of an electromagnet seat, an electromagnet coil, an electromagnet rotor, an electromagnet rotor reset spring, a friction plate and a manual unlocking unit, wherein the electromagnet rotor is provided with a plurality of stator support sleeve through holes, a stator support sleeve is passed through the stator support sleeve through holes, the electromagnet rotor is slidably connected with the stator support sleeve, one end face of the stator support sleeve contacts the electromagnet seat, and the other end face of the stator support sleeve contacts the stator, the stator is fixedly connected with the electromagnet seat by a stator fixing screw to form an inclusive space structure of the electromagnet rotor and the friction plate, a friction plate is arranged between the electromagnet rotor and the stator, the outer circle of the friction plate is evenly distributed with connecting wings, and the connecting wings are engaged with the rotor grooves at the corresponding positions of the rotor to form an integrated structure. The height of the stator support sleeve is the thickness of the electromagnet rotor + the thickness of the friction plate + 0.1mm to 0.2mm.

[0020] The preferred solution of this embodiment is that the electromagnet movable plate is provided with an unlocking screw through hole, the unlocking screw is screwed with the unlocking screw threaded hole on the electromagnet seat, the left end of the unlocking screw is provided with a screwdriver transverse groove, and the fixed plate is provided with a manual unlocking process hole 9-1 at the position corresponding to the unlocking screw through hole. The function of the manual unlocking process hole is: after the electronic brake assembly is assembled, the screwdriver transverse groove at the rear end of the unlocking screw can be exposed through the manual unlocking process hole, and manual unlocking can be achieved using a screwdriver.

[0021] The preferred solution of this embodiment is that the friction plate is provided with a friction plate step 8-2 facing the direction of the electromagnet moving plate. The diameter of the friction plate step in this embodiment is smaller than the diameter of the electromagnet stator. The purpose of providing the friction plate step is to prevent bending stress from being generated at the contact portion between the friction plate and the outer diameter of the electromagnet stator, and to prevent the electromagnet moving plate from impacting the outer edge of the friction plate during repeated attraction and release actions, thereby causing premature damage to the friction plate. When the electromagnet moving plate is released, it only fits against the friction plate step to avoid damage to the outer edge of the friction plate.

[0022] Working process and principle

[0023] When the electric wheelchair is in a non-electric driving state, the electromagnet is powered off. The electromagnet movable plate presses the friction plate onto the stator under the action of the electromagnet movable plate reset spring. The friction plate is sandwiched between the stator and the movable plate and is squeezed, generating friction to prevent the rotor from rotating, and generating anti-slip resistance for the wheel hub motor to prevent slipping. When electric driving is required, the electromagnet is energized to attract the electromagnet movable plate along the axial movement of the main shaft. The friction plate will no longer be squeezed by the stator and the movable plate. The friction plate can rotate freely between the stator and the movable plate as the rotor rotates. The rotational movement of the rotor is free from resistance, and the wheel hub motor drives the wheelchair to travel. When the battery of the electric wheelchair is low on power, the motor and the electromagnet cannot work. Since the electromagnet cannot work, the movable plate is always in a state of squeezing the friction plate. The friction plate prevents the rotor from rotating, and the wheelchair cannot be pushed manually. At this time, if you want to push the wheelchair manually, you first need to manually release the anti-slip resistance so that you can easily push the wheelchair.

[0024] Figure 1-4 As shown in the figure, the unlocking screw and the electromagnet movable plate support sleeve are both arranged inside the middle hole of the friction plate, and the friction plate rotates freely around the unlocking screw and the electromagnet support sleeve, and the outer diameter connecting wing of the friction plate can be directly keyed to the rotor, which greatly simplifies the connection structure between the friction plate and the rotor. Compared with the existing electromagnetic brake friction plate center connection method with the rotor, it not only reduces the radial size but also can remove the connecting piece connecting the rotor and the center of the friction plate, which reduces both the weight and the axial size, reduces the overall motor volume and weight, and is conducive to realizing lightweight and miniaturization of wheelchairs.

[0025] The friction torque of the electromagnetic brake device is related to the pressure on the friction plate and the size of the friction plate lever arm. The present invention places the support sleeve inside the center hole of the friction plate, which maximizes the effective lever arm size of the friction plate. Under the same pressure conditions, the same friction torque can be achieved with a smaller size, achieving the purpose of lightweight and miniaturization.

[0026] The assembly sequence is as follows: install the coil and the electromagnet movable plate reset spring in the electromagnet seat, the unlocking screw passes through the unlocking screw through-hole on the electromagnet movable plate and is screwed into the electromagnet seat, hook the electromagnet movable plate through the cap of the unlocking screw, overcome the elastic force of the electromagnet movable plate reset spring to pull the electromagnet movable plate to the electromagnet surface, and make the movable plate close to the electromagnet seat, insert the four stator support sleeves into the stator support sleeve through-holes respectively and align them with the threaded holes on the electromagnet seat, place the hollow part of the hollow friction plate on the movable plate to accommodate the above-mentioned stator support sleeve and the unlocking screw, and the stepped table of the friction plate contacts the movable plate, then place the stator and penetrate the stator and the stator support sleeve with screws to screw them to the electromagnet seat, so that a certain distance is maintained between the stator and the electromagnet surface, and this distance is the same as the height of the stator support sleeve, and is equal to the sum of the thickness of the friction plate and the stator plus the movable gap of the movable plate, and the specific size of the gap is 0.1mm~0.2mm. When the electromagnet with the motor plate is attracted to the electromagnet seat, the above gap exists between the moving plate and the fixed plate, so that the friction plate can rotate freely between the fixed plate and the moving plate. When the electromagnet is powered off, the fixed plate is separated from the electromagnet seat by the reset spring, and the above gap exists between the moving plate and the electromagnet seat. The friction plate is clamped by the moving plate and the fixed plate. At this time, the friction plate is restricted from rotating, providing anti-slip resistance to the motor rotor. When manually unlocking, the unlocking handle drives the unlocking screw to rotate, forcibly pulling the moving plate back and pressing it against the electromagnet seat to generate the above gap between the moving plate and the fixed plate, so that the friction plate can rotate freely, removing the anti-slip resistance.

[0027] The detailed description of the wheel hub motor for a wheelchair with a safety brake device with reference to the above embodiment is illustrative rather than restrictive, and several embodiments can be listed according to the limited scope. Therefore, changes and modifications without departing from the overall concept of the present invention should fall within the scope of protection of the present invention.

Claims

1. A wheel hub motor for a wheelchair with a safety brake device, comprising a stator, a rotor and a brake anti-slip mechanism mainly composed of an electromagnet seat, an electromagnet coil, an electromagnet rotor, an electromagnet rotor return spring, a friction plate and a manual unlocking unit, wherein the center of the electromagnet seat is provided with a coil fixing boss, the electromagnet coil is sleeved on the coil fixing boss, and the coil fixing boss is provided with an electromagnet rotor return spring countersunk hole, wherein the characteristics are: The electromagnet moving piece is provided with a plurality of stator support sleeve through holes, and a stator support sleeve is passed through the stator support sleeve through holes. The electromagnet moving piece is slidably connected with the stator support sleeve, and one end face of the stator support sleeve contacts with the surface of the coil fixing boss of the electromagnet seat, and the other end face of the stator support sleeve contacts with the stator. The stator is fixedly connected with the electromagnet seat by a stator fixing screw to form an inclusive space structure of the electromagnet moving piece and the friction plate. A friction plate is arranged between the electromagnet moving piece and the stator, and the outer circle of the friction plate is evenly distributed with connecting wings, and the connecting wings correspond to the rotor. The rotor grooves at the positions are embedded in an integrated structure, the stator support sleeve is fixed on the surface of the coil fixing boss, and the stator support sleeve is completely contained in the inner circle of the friction plate; an unlocking screw through hole is provided on the electromagnet moving plate, the unlocking screw is screwed with the unlocking screw threaded hole on the electromagnet seat, a screwdriver transverse groove is provided at the rear end head of the unlocking screw, and a manual unlocking process hole is provided on the stator corresponding to the unlocking screw through hole position; the friction plate is provided with a friction plate step facing the electromagnet moving plate, and the diameter of the friction plate step is smaller than the diameter of the electromagnet stator.

2. The wheel hub motor with a safety brake device for a wheelchair according to claim 1, characterized in that: The height of the stator support sleeve is the thickness of the electromagnet moving plate + the thickness of the friction plate + 0.1mm~0.2mm.

3. The wheel hub motor with a safety brake device for a wheelchair according to claim 1, characterized in that: The number of the stator support sleeve through holes and the stator support sleeve is 3-4, and they are arranged on concentric circles.

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