In-wheel motor with electronic brake module

Abstract

Disclosed herein an in-wheel motor with a brake module. The in-wheel motor comprises an upper cover 1 of a circular shape, having a shaft 10 coupled in the center, a brake module 2 positioned in a lower part of the upper cover 1 and installed on an upper part of a stator 3 fixedly installed on the shaft 10, and a rotor 4 coupled to the upper cover 1 and installed on an outer circumferential surface of the stator 3 to rotate, wherein the brake module 2 comprises: a brake ring 20 having a ring shape and having a plurality of braking protrusions 20A protruding upward, and a brake driving part 21 installed on an outer side of the brake ring 20 to move the brake ring 20 downward, and the plurality of braking protrusions 20A are inserted into braking grooves 11 formed on the upper cover 1, respectively.

Description

IN-WHEEL MOTOR WITH ELECTRONIC BRAKE MODULE

[0001] The present invention relates to an in-wheel motor provided within a wheel of a vehicle. More specifically, the present invention relates to an in-wheel motor with an electronic brake module for preventing the rotation of the rotor of a motor when the driving of the in-wheel motor is stopped.

[0002] In general, in-wheel motors are used in transportation devices which use electric motors as a power source, such as vehicles, robots, electric bicycles, electric wheelchairs, etc. Such in-wheel motors are widely used to drive the wheels of transportation devices because the motors can be installed in-wheel, without requiring a separate drive shaft or transmission, thereby saving space.

[0003] When such in-wheel motors are used in server robots or electric wheelchairs, a brake module must be installed to prevent sliding when the server robots or electric wheelchairs are stopped or parked on a slope. In particular, the brake module plays a very important role when the floor surface is sloped, because if the robot or electric wheelchair cannot prevent the wheels from sliding down the slope while stationary, safety may be compromised.

[0004] Korean Patent Laid-Open No. 10-2020-0092776 discloses a structure for rim brakes by installing a brake device on the outside of the rim coupled to the outside of the rotor. The brake device has the advantage of having a simple structure in which a pin is coupled to a groove formed on a brake drum, but since the brake device is installed on the outer side of the rim, there are limitations in reducing the size of the motor.

[0005] Korean Patent No. 10-1284046 discloses a structure in which a brake drum is installed inside an in-wheel motor, and the brake drum is operated by a brake shoe installed outside the housing. In this patent, the housing in which the brake shoe is installed has a double housing and is located inside the stator, and the brake drum must be installed in the rotor housing, resulting in a complex structure and a large number of parts.

[0006] Accordingly, the present inventors suggest an in-wheel motor of a new structure, capable of reducing the size of the motor by providing a brake module inside the in-wheel motor.

[0007] It is an object of the present invention to provide an in-wheel motor that can reduce the size of the motor by installing the brake module on an inner side of the rotor.

[0008] It is another object of the present invention to provide an in-wheel motor having a brake module of a simple structure.

[0009] It is yet another object of the present invention to provide an in-wheel motor that is electronically operated by a power source to have excellent braking performance.

[0010] The above and other inherent objects of the present invention may all be easily achieved by the description of the present invention described below.

[0011] An in-wheel motor with a brake module according to the present invention comprises an upper cover 1 of a circular shape, having a shaft 10 coupled in the center, a brake module 2 positioned in a lower part of the upper cover 1 and installed on an upper part of a stator 3 fixedly installed on the shaft 10, and a rotor 4 coupled to the upper cover 1 and installed on an outer circumferential surface of the stator 3 to rotate, wherein the brake module 2 comprises: a brake ring 20 having a ring shape and having a plurality of braking protrusions 20A protruding upward, and a brake driving part 21 installed on an outer side of the brake ring 20 to move the brake ring 20 downward, and the plurality of braking protrusions 20A are inserted into braking grooves 11 formed on the upper cover 1, respectively.

[0012] In the present invention, the brake driving part 21 is coupled to an upper part of the stator core 30 of the stator 3.

[0013] In the present invention, the brake driving part 21 comprises a bobbin 230 around which a coil 240 is wound, an upper case 210 and a lower case 220 are coupled to an upper part and a lower part of the bobbin 230, respectively, and a plurality of fixing protrusions 221 formed on the lower case 220 to protrude downward are coupled to a plurality of coupling holes 304B formed on an upper part of the stator core 30.

[0014] In the present invention, a plurality of first magnets 260 are installed on an upper part of the inner circumferential surface of the bobbin 230, a plurality of second magnets 270 are installed on a lower part of the inner circumferential surface of the bobbin 230, and a plurality of ring yokes 250 are installed between the first magnet 260 and the second magnet 270.

[0015] In the present invention, when power is applied to the brake driving part 21, the brake ring 20 moves downward, and the braking protrusion 20A inserted into the braking groove 11 is separated from the braking groove 11.[

[0016] The present invention has the effect of providing an in-wheel motor that can reduce the size of the motor by installing the brake module on the inner side of the rotor, has a brake module of a simple structure, and is electronically operated by a power source to have excellent braking performance.

[0017] Fig. 1 is a perspective view of an in-wheel motor according to the present invention;

[0018] Fig. 2 is a top exploded perspective view of an in-wheel motor according to the present invention;

[0019] Fig. 3 is a bottom exploded perspective view of an in-wheel motor according to the present invention;

[0020] Fig. 4 is an exploded perspective view of an upper cover and a shaft of an in-wheel motor according to the present invention;

[0021] Fig. 5 is an exploded perspective view of a rotor of an in-wheel motor according to the present invention;

[0022] Fig. 6 is a perspective view of a brake module of an in-wheel motor according to the present invention;

[0023] Fig. 7 is an exploded perspective view of a brake module and a stator core of an in-wheel motor according to the present invention;

[0024] Fig. 8 is a bottom exploded perspective view of a brake ring in a brake module of an in-wheel motor according to the present invention; and

[0025] Fig. 9 is an exploded perspective view of a brake driving part of an in-wheel motor according to the present invention.

[0026] Hereinafter, the present invention will be explained in detail with reference to the accompanying drawings.

[0027] Fig. 1 is a perspective view of an in-wheel motor according to the present invention. Fig. 2 is a top exploded perspective view of an in-wheel motor according to the present invention. Fig. 3 is a bottom exploded perspective view of an in-wheel motor according to the present invention. Fig. 4 is an exploded perspective view of an upper cover 1 and a shaft 10 of an in-wheel motor according to the present invention. Fig. 5 is an exploded perspective view of a rotor 4 of an in-wheel motor according to the present invention.

[0028] Referring to Figs. 1 to 5 together, the in-wheel motor according to the present invention comprises an upper cover 1, a brake module 2, a stator 3, and a rotor 4.

[0029] The upper cover 1 has a shaft 10 fixedly coupled in the center to protrude downward. For reference, "upper" is used herein to mean an upward direction and "lower" to mean a downward direction with reference to Figs. 1 and 2. The upper cover 1 is coupled to an upper part of the rotor 4, and the stator 3 fixed to the shaft 10 is positioned inside the rotor 4. The rotor 4 is rotatably coupled to an outer circumferential surface of the shaft 10 fixed to the outside of the stator 3. Thus, the rotor 4 rotates together with the upper cover 1 having the shaft 10 as an axis. A tire (not shown) may be coupled to an outer circumferential surface of the rotor 4.

[0030] The brake module 2 is installed on an upper part of the stator 3. The brake module 2 has a brake ring 20 and a brake driving part 21, and the brake ring 20 is positioned on an inner side of the brake driving part 21 to be movable up and down.

[0031] A wiring tube 5 is installed through a hollow hole 102 of the shaft 10. The wiring tube 5 receives therein lead wires (not shown) for supplying an external power to the brake module 2 and the stator 3.

[0032] The upper cover 1 has a circular shape, and forms a through hole 10A in the center part for the shaft 10 to penetrate and be coupled. An upper bearing insert 10B is formed around the through hole 10A so that an upper bearing 13 is coupled to the upper bearing insert 10B. Preferably, the upper bearing 13 is a ball bearing.

[0033] The outer circumferential surface of the upper bearing 13 is pressedly fixed to the upper bearing insert 10B, and the inner circumferential surface of the upper bearing 13 is coupled to the outer circumferential surface of the shaft 10 so that the upper cover 1 is rotatably supported with respect to the shaft 10.

[0034] A plurality of braking grooves 11 are formed on a lower part of the upper cover 1 and / or around the upper bearing inserts 10B of the upper cover 1. Braking protrusions 20A protruding upward from the brake ring 20 of the brake module 2 may be coupled to the braking grooves 11.

[0035] A plurality of first coupling holes 12 are formed along the outer circumferential surface of the upper cover 1. The first coupling hole 12 is a configuration for a coupling means such as a bolt to penetrate, so that the upper cover 1 may be coupled to a rotor housing 41 of the rotor 4.

[0036] The shaft 10 has a fixing plate 101 formed to be larger than the diameter of the shaft 10 on an upper part thereof. Thus, the shaft 10 has a "T" shape when viewed from the side. A plurality of fixing holes 101A are formed on the fixing plate 101. The fixing hole 101A is formed to fix the fixing plate 101 to a main body of the robot, vehicle or electric wheelchair by a coupling means such as a bolt.

[0037] The shaft 10 of the present invention has an internally hollow shape. A hollow hole 102 is formed inside the shaft 10 so that the hollow hole 102 penetrates from the fixing plate 101 on an upper part of the shaft 10 to a lower part of the shaft 10. A wiring tube 5 is installed to penetrate the hollow hole 102.

[0038] The rotor 4 comprises a rotor housing 41, a lower cover 42, a yoke 43, a rotor magnet 44, and a lower bearing 45. The rotor housing 41 is integrally formed with the lower cover 42 in a cup shape, and the stator 3 is positioned in an inner space of the rotor housing 41.

[0039] A plurality of second coupling holes 41A are formed on an upper surface of the rotor housing 41 at locations corresponding to the first coupling holes 12 of the upper cover 1. A coupling means such as a bolt or a screw, penetrates the first coupling hole 12 and is coupled to the second coupling hole 41A so that the rotor housing 41 is coupled to the upper cover 1.

[0040] A ring-shaped magnetic yoke 43 is coupled on an inner circumferential surface of the rotor housing 41, and a plurality of rotor magnets 44 are attached to the inner circumferential surface of the yoke 43. The rotor magnets 44 are spaced apart from the teeth 302 of the stator 3 at certain intervals to face each other.

[0041] A lower bearing insert 42A is formed on an upper part and / or a center part of the lower cover 42. An outer circumferential part of the lower bearing 45 is pressedly coupled to the lower bearing insert 42A. A lower end of the shaft 10 is coupled to an inner circumferential part of the lower bearing 45 so that the lower cover 42 and the rotor housing 41 are rotatably supported with respect to the shaft 10.

[0042] The stator 3 comprises a stator core 30, an upper insulator 31, a lower insulator 32, and a PCB cover 33.

[0043] The stator core 30 has a core base 301 of a cylindrical shape, a plurality of teeth 302 radially protruding from the core base 301, and a shaft coupling part 303 to which the shaft 10 is coupled. The shaft coupling part 303 may be a hole vertically penetrating the core base 301, and as illustrated in Fig. 7, may be a cylindrical member having a shaft coupling hole 303A to which the shaft 10 is coupled. Fig. 7 illustrates the shaft coupling part 303 has a cylindrical shape in which a shaft coupling hole 303A is formed in the center. In this case, the outer circumferential surface of the shaft coupling part 303 and the inner circumferential surface of the core base 301 are connected by a plurality of bridges 304. The space between the bridge 304 and the core base 301 and the shaft coupling part 303 is a cooling hole 305, which serves to cool the heat generated by the stator 3 as air passes therethrough, and to reduce the weight of the stator core 30 and save materials.

[0044] The upper insulator 31 made of an insulating material covers an upper part of the stator core 30. The lower insulator 32 made of an insulating material covers a lower part of the stator core 30. In particular, the upper part and the lower part of the teeth 302 of the stator core 30 are wrapped by the upper insulator 31 and the lower insulator 32, and in this state, a winding coil is wound around each tooth 302 as illustrated in Fig. 2. The upper insulator 31 and the lower insulator 32 may be formed to cover a portion of the upper part and the lower part of the core base 301 and / or shaft coupling part 303. The PCB cover 33 is coupled to a lower part of the lower insulator 32 and receives a printed circuit board (PCB) therein.

[0045] The brake module 2 is coupled to an upper part of the stator 3. The brake module 2 comprises a brake ring 20 and a brake driving part 21. The brake module 2 puts on a brake so as to stop rotating when the upper cover 1 coupled to the rotor 4 to rotate together stops rotating. A detailed configuration of the brake module 2 is described with reference to Figs. 6 to 9 below.

[0046] Fig. 6 is a perspective view of a brake module 2 of an in-wheel motor according to the present invention. Fig. 7 is an exploded perspective view of a brake module 2 and a stator core 30 of an in-wheel motor according to the present invention. Fig. 8 is a bottom exploded perspective view of a brake ring 20 in a brake module 2 of an in-wheel motor according to the present invention. Fig. 9 is an exploded perspective view of a brake driving part 21 of an in-wheel motor according to the present invention.

[0047] As illustrated in Figs. 6 to 9, the brake module 2 of the present invention comprises a brake ring 20 having a ring shape, and a brake driving part 21 having a ring shape and positioned on an outer circumferential surface of the brake ring 20. The brake ring 20 is positioned on an inner side of the brake driving part 21 to be movable up and down.

[0048] Specifically, the brake ring 20 is pushed upward by a spring 200 installed on a lower part of the brake ring 20 when the in-wheel motor is not driven, so that the braking protrusions 20A formed on an upper part of the brake ring 20 are coupled to the braking grooves 11 of the upper cover 1, thereby stopping the upper cover 1 and the rotor 4. Thus, even when a device with an in-wheel motor, such as a server robot or an electric wheelchair, is located on a slope, the device is stopped without slipping down the slope.

[0049] When the in-wheel motor is driven, power is applied to the brake driving part 21 to create a magnetic field inside the brake driving part 21, and the brake ring 20, which is magnetic, is pulled downward by the magnetic field. Thus, the brake ring 20 moves downward as the spring 200 of the lower part is compressed, causing the braking protrusions 20A to be separated from the braking grooves 11, allowing the upper cover 1 and the rotor 4 to rotate.

[0050] As mentioned above, preferably, the brake ring 20 is magnetic and has a ring shape. A plurality of braking protrusions 20A are formed to protrude upward from the brake ring 20. A plurality of spring coupling protrusions 20B are formed to protrude downward on a lower part of the brake ring 20.

[0051] A spring 200 is coupled to the spring coupling protrusion 20B, and the spring coupling protrusion 20B is positioned with the spring 200 coupled to a spring receiving hole 304A formed on the stator core 30. The spring 200 is positioned between the spring receiving hole 304A and the brake ring 20 to exert a force that elastically pushes the brake ring 20 upward, thereby causing the braking protrusion 20A to be coupled to the braking groove 11.

[0052] In Fig. 7, the spring receiving hole 304A is formed on the bridge 304 of the stator core 30, but the location of the spring receiving hole 304A is not limited thereto. The spring receiving hole 304A may be formed on the core base 301 or the upper insulator 31, rather than on the bridge 304.

[0053] The brake driving part 21, which is a device that creates a magnetic field when power is applied, comprises an upper case 210, a lower case 220, a bobbin 230, and a coil 240.

[0054] The bobbin 230 has a ring shape, and the upper part and the lower part of the bobbin 230 have an outwardly extending flange shape. A coil 240 is wound around the outer surface of the bobbin 230. The upper case 210 is coupled to an upper part of the bobbin 230 and the lower case 220 is coupled to a lower part of the bobbin 230 to enclose the bobbin 230 around which the coil 240 is wound. A plurality of fixing protrusions 221 protrude downwardly of the lower case 220. An end of the coil 240 is drawn out through an outlet 222 formed on one side of the lower case 220 and electrically connected to a printed circuit board housed in the PCB cover 33.

[0055] The fixing protrusion 221 of the lower case 220 is coupled to a coupling hole 304B formed on the stator core 30 to serve to fix the brake driving part 21. In Fig. 7, the coupling hole 304B is formed on the bridge 304 of the stator core 30, but the location of the coupling hole 304B is not limited thereto. The coupling hole 304B may be formed on the core base 301 or the upper insulator 31, rather than on the bridge 304.

[0056] A plurality of first magnets 260 may be installed on an upper part of the inner circumferential surface of the bobbin 230 as illustrated in Fig. 8. A plurality of second magnets 270 may be installed on a lower part of the inner circumferential surface of the bobbin 230. A plurality of ring yokes 250 may be installed between the first magnet 260 and the second magnet 270. The first magnet 260 and the second magnet 270 serve to complement the electromagnetic force generated by the coil 240 wound around the bobbin 23, and thus may be installed on the inner circumferential surface of the bobbin 230 or omitted, as needed.

[0057] It should be noted that the description of the present invention described above is merely an example for understanding the present invention, and is not intended to limit the scope of the present invention. It should be construed that the scope of the present invention is defined by the appended claims, and all modifications and alternations of the present invention fall within the protection scope of the present invention.

Claims

1.An in-wheel motor with a brake module, comprising:an upper cover 1 of a circular shape, having a shaft 10 coupled in the center;a brake module 2 positioned in a lower part of the upper cover 1 and installed on an upper part of a stator 3 fixedly installed on the shaft 10; anda rotor 4 coupled to the upper cover 1 and installed on an outer circumferential surface of the stator 3 to rotate;wherein the brake module 2 comprises: a brake ring 20 having a ring shape and having a plurality of braking protrusions 20A protruding upward; and a brake driving part 21 installed on an outer side of the brake ring 20 to move the brake ring 20 downward, andthe plurality of braking protrusions 20A are inserted into braking grooves 11 formed on the upper cover 1, respectively.2.The in-wheel motor of claim 1, wherein the brake driving part 21 is coupled to an upper part of the stator core 30 of the stator 3.3.The in-wheel motor of claim 2, wherein the brake driving part 21 comprises a bobbin 230 around which a coil 240 is wound, an upper case 210 and a lower case 220 are coupled to an upper part and a lower part of the bobbin 230, respectively, and a plurality of fixing protrusions 221 formed on the lower case 220 to protrude downward are coupled to a plurality of coupling holes 304B formed on an upper part of the stator core 30.4.The in-wheel motor of claim 3, wherein a plurality of first magnets 260 are installed on an upper part of the inner circumferential surface of the bobbin 230, a plurality of second magnets 270 are installed on a lower part of the inner circumferential surface of the bobbin 230, and a plurality of ring yokes 250 are installed between the first magnet 260 and the second magnet 270.5.The in-wheel motor of claim 1, wherein when power is applied to the brake driving part 21, the brake ring 20 moves downward, and the braking protrusion 20A inserted into the braking groove 11 is separated from the braking groove 11.

Images