Electric vehicle and method of manufacturing the same

Abstract

The present application provides an electric vehicle and a manufacturing method thereof, which is configured to reduce the bearings, gears, and brakes arranged on the outside of rotating parts, and reduce the heat generation. The outer ring of the wheel is formed by a sliding bearing, and the inner ring opposite to the outer ring is supported by a support frame of a suspension device, and is provided with a stator constituting a motor. The rotor opposite to the stator of the inner ring is arranged on the other outer ring. The brake device is arranged on the outside of the sliding bearing and the outer ring, and can clamp the brake disc on the inner ring.

Description

Technical Field

[0001] This invention relates to an electric vehicle equipped with a hub motor and a method for manufacturing the same. Background Technology

[0002] Currently, motor technology is advancing, and high-speed rotating motors, reducers, and brakes are now integrated into wheels. The higher the rotational speed, the more frictional heat is generated, necessitating increased cooling power consumption to reduce heat generation within the enclosed space of the wheel. Such a hub motor has been described in Patent Document 1. Because the hub motor is integrated into various devices within the wheel, the components are close to each other, and the brake is enclosed, preventing heat from escaping. The extensive use of metal rolling bearings and gears generates heat due to high-speed rotation, thus increasing the power consumption for cooling.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 3440082 Summary of the Invention

[0006] The technical problem that the invention aims to solve

[0007] The goal is to directly connect the rotor to the wheel, which has fewer rotating parts such as bearings and gears, and where the brakes are located on the outside and heat generation is reduced.

[0008] Technical solutions for solving technical problems

[0009] To achieve the above objectives, the electric vehicle of the present invention comprises an outer ring for mounting wheels formed by sliding bearings and an inner ring opposite thereto, the inner ring being supported by a support frame of a suspension device and having a stator constituting a motor, and a rotor opposite to the stator of the inner ring being provided on the other outer ring.

[0010] In this case, a braking device is provided on the outer ring of the sliding bearing, which can clamp the brake disc on the inner ring.

[0011] Furthermore, the device can be configured such that a resin metal is provided on the sliding surfaces of the outer and inner rings. One or more recesses are provided on the outer ring to position the resin metal, and the resin metal has protrusions that are accommodated in the plurality of recesses, with a circuit for lubricating oil and air to escape from the bottom of the recesses.

[0012] In addition, a drive motor with a reducer and an electromagnetic clutch is installed in the support frame. By switching to the electromagnetic clutch, the driving force can be transmitted to the support ring only at low speeds and during reversal.

[0013] The electric vehicle manufacturing method of the present invention is characterized in that, during the process of forming an outer ring for mounting a wheel and an inner ring opposite it by a sliding bearing, and setting resin metal on the sliding surface of the outer ring and the inner ring, a softening agent is used to temporarily soften the resin metal, a gap-filling gasket corresponding to an oil gap is embedded between the resin metal and the inner ring, the outer ring is mounted using a side ring, the resin metal is decomposed after curing, the gap-filling gasket is removed, and an oil gap of a specified value is formed.

[0014] The effects of the invention

[0015] With the above structure, in this invention, because the wheel's rotation mechanism is a sliding bearing structure, there are no rolling bearings or other heat sources in the main rotation mechanism. Furthermore, because the braking device is located outside the outer rim, it provides a heat dissipation function. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the tire mounting section of an electric vehicle according to an embodiment of the present invention.

[0017] Figure 2 yes Figure 1 Enlarged cross-sectional view.

[0018] Figure 3 This is a cross-sectional view of the tire mounting section of the electric vehicle according to the second embodiment.

[0019] Figure 4 This is an enlarged cross-sectional view of the tire mounting portion of the electric vehicle according to the third embodiment, including the resin shaft metal, the cooling jacket for the inner ring and stator, and a portion of the cooling circuit.

[0020] Figure 5 This is a diagram showing the installation of the side ring that forms the oil gap in the resin shaft metal. Detailed Implementation

[0021] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the embodiments described below are only a portion of suitable methods for implementing the present invention; changes to the structure or method, even if they result in the same effect, can also be considered part of the present invention.

[0022] Figure 1 , Figure 2 The figures show a cross-sectional view and a partial enlarged cross-sectional view of the hub motor constituting the electric vehicle of the present invention. As shown in the figures above, the wheel 12 has a tire 10 mounted on it, and the wheel 12 is directly mounted on the sliding bearing 16 via a protrusion 14 provided near the outer side of the inner circumferential surface.

[0023] The sliding bearing 16 consists of multiple outer rings 18 and inner rings 20, which slide together via a stepped sliding surface 22. The step on the sliding surface 22 is higher on the vehicle body side so that the inner ring 20 can be removed facing the vehicle body side. In addition, in order to prevent lateral vibration of the sliding bearing 16, it is configured such that a side ring 24 is installed on the smallest step portion on the inner ring 20 side to suppress the maximum protrusion of the outer ring 18.

[0024] A ring-shaped support ring 26 is installed on the outer ring 18 to cover the central opening of the tire 10 on the outer side of the vehicle. This support ring 26 extends beyond the side portion of the inner ring 20, leaving the radial center of the tire 10 open. The open end is bolted and covered by a flat cover 28. An L-shaped support frame 30 is installed on the inner side of the inner ring 20. The L-shaped front end of the support frame 30 is mounted on the outer surface of the inner ring 20, extending with its base plate facing the center of the tire. The central portion is covered by a cover 32 and secured with bolts. Furthermore, the support frame 30 is supported by the suspension device 34 at both the upper and lower positions.

[0025] A stator 36, forming part of the hub motor, is disposed at a corner of the support frame 30, and a rotor 38, opposite the stator 36, is disposed on its lower surface. That is, the stator 36 is glued to the support frame 30 and thus serves as the stator frame. The opposing rotor 38 is fixed to the support ring 26 mounted on the outer ring 18 via a base 40. Therefore, when the rotor 38 is subjected to a driving force, the tire 10 rotates via the base 40, the support ring 26, and the outer ring 18, and the rotational driving force is transmitted by sliding relative to the inner ring 20.

[0026] In addition, such as Figure 1 , Figure 2 As shown, in the above embodiment, a brake disc 42 is mounted on the extended end of the outer ring 18. On the other hand, a braking device 44 capable of holding the brake disc is mounted on a support frame 30 located on the lower surface of the wheel. This enables an electric vehicle to have brakes that are in contact with outdoor air.

[0027] like Figure 2 As shown, on the sliding surface 22 of the sliding bearing 16, multiple positioning recesses 46 are provided on the outer ring 18, allowing resin metal 48 to exist on the sliding surface 22, and protrusions 50 are provided thereto to accommodate the multiple recesses 46. Because the resin metal 48 has a low coefficient of friction and suppresses heat generation, it does not produce metal powder, thus maintaining the quality of the lubricating oil for a long time. An escape passage 52 for lubricating oil and air is provided at the bottom of the recesses 46 of the outer ring 18. It should be noted that an oil seal 54 is disposed between the outer ring 18 and the inner ring 20.

[0028] In the electric vehicle of the embodiment described above, the tire 10 is configured to rotate via a sliding bearing 16, and the braking means rely on a brake disc 42 provided at the extended end of the outer ring 18 and a braking device 44 provided in the support frame 30. Therefore, since the tire 10 is driven by rotation, problems such as noise from gear mechanisms and rolling bearings, as well as cooling problems of the brakes, can be solved simultaneously.

[0029] then, Figure 3 The second embodiment is shown. In this embodiment, a drive motor 56 is mounted in the center of the support frame 30, thereby mounting a front-end reducer 58 and an electromagnetic clutch 60, which are held together with the opposing support ring 26. On the other hand, an air supply pipe 62 and a return pipe 64 for cooling are connected at two locations on the support frame 30. This is to allow the driving force to be transmitted to the support ring 26 and even the tire 10 only at low speeds and when reversing, by switching operations.

[0030] According to this embodiment, the drive motor 56 can be activated even with a large initial movement, while simultaneously forcibly blowing cooling air.

[0031] Figure 4 This describes the third embodiment. Cooling jackets 66 are formed at multiple locations on the support frame 30. Additionally, a cooling jacket 68 is also formed on the fixed side of the sliding bearing 16, i.e., the inner ring 20. The cooling jackets 66 and 68 are interconnected via a connecting passage 70, allowing cooling oil to flow between them. The cooling jacket 68 on the inner ring 20 has an outlet 72 extending to the sliding surface 22, enabling the supply of cooling oil to the sliding surface.

[0032] According to this embodiment, because the sliding surface 22 of the sliding bearing 16, which is prone to heat generation, can be cooled by cooling oil at all times, stable operation is possible.

[0033] Figure 5 This is an explanatory diagram of the fourth embodiment. A resin metal 48 with a low coefficient of friction is provided between the sliding surfaces 22 of the sliding bearing 16. During installation of the resin metal 48, a softener is used to temporarily soften the resin metal 48. A gap-filling gasket 74, corresponding to an oil gap, is embedded between the inner ring 20 and the resin metal 48, and between the side ring 24 and the resin metal 48. The outer ring 18 is installed using the side ring 24. After the resin metal 48 cures, it decomposes, and the gap-filling gasket 74 is removed, thereby forming an oil gap of a specified value.

[0034] This allows for a simple installation method for the resin metal 48.

[0035] As described above, in this invention, because the wheel's rotation mechanism is a sliding bearing structure, there are no rolling bearings or other heat sources in the main rotation mechanism. Furthermore, because the braking device is located outside the outer rim, it provides a heat dissipation function.

[0036] The resin metal entering between the outer and inner rings has a low coefficient of friction, generates less heat, and does not produce metal powder, thus maintaining the quality of the lubricating oil for a long time and enabling its application in stator cooling.

[0037] The stator's support frame is the size of a wheel. The large-diameter rotor generates torque even at low speeds, eliminating the need for a speed reducer. The direct connection between the rotor and the wheel lacks gears and bearings, thus reducing heat generation. The reduced power consumption for cooling and fewer moving parts lower the risk of failure.

[0038] Large-diameter brake discs, about the size of a wheel, improve braking performance, are easy to inspect visually, and are exposed to outdoor air, resulting in good heat dissipation for the brake discs and braking system.

[0039] Explanation of reference numerals in the attached figures

[0040] 10 Tire; 12 Wheel; 14 Protrusion; 16 Sliding Bearing; 18 Outer Ring; 20 Inner Ring; 22 Sliding Surface; 24 Side Ring; 26 Support Ring; 28 Cover; 30 Support Frame; 32 Cover; 34 Suspension Device; 36 Stator; 38 Rotor; 40 Base; 42 Brake Disc; 44 Braking Device; 46 Recess; 48 Resin Metal; 50 Protrusion; 52 Air Exit Passage; 54 Oil Seal; 56 Drive Motor; 58 Reducer; 60 Electromagnetic Clutch; 62 Air Supply Pipe; 64 Return Pipe; 66 Cooling Jacket; 68 Cooling Jacket; 70 Connecting Path; 72 Outlet; 74 Gap Filler Gasket.

Claims

1. An electric vehicle, characterized in that, An outer ring for mounting a wheel and an inner ring opposite it are formed by a sliding bearing. The inner ring is supported by a support frame of the suspension device and has a stator that constitutes a motor. On the other hand, a rotor opposite the stator of the inner ring is provided on the outer ring. A resin metal is provided on the sliding surface between the outer ring and the inner ring. One or more recesses for positioning the resin metal are provided on the outer ring. The resin metal has protrusions that are accommodated in the plurality of recesses and a circuit for lubricating oil and air to escape from the bottom of the recesses.

2. The electric vehicle according to claim 1, characterized in that, A drive motor with a reducer and an electromagnetic clutch is installed in the support frame. By switching to the electromagnetic clutch, the driving force is transmitted to the support ring only at low speed and during reversal.

3. A method for manufacturing an electric vehicle, characterized in that, In the process of forming an outer ring for mounting a wheel and an inner ring opposite it by a sliding bearing, and setting resin metal on the sliding surface of the outer ring and the inner ring, a softener is used to temporarily soften the resin metal, and a gap-filling gasket equivalent to an oil gap is embedded between the resin metal and the inner ring. The outer ring is installed using a side ring. After the resin metal is cured, it is decomposed, and the gap-filling gasket is removed to form an oil gap of a specified value.

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