Electric machine and actuator

Abstract

The utility model discloses a motor and actuator, the motor includes stator and rotatablely configured in the rotor central of stator, the rotor includes the pivot, is fixed with first interval sleeve and second interval sleeve on the pivot, the side end of stator is equipped with end cover, the axial one side of end cover is provided with first accommodating hole, is equipped with the shaft sleeve in first accommodating hole, the axial other side of end cover is provided with wear plate, the shaft sleeve and wear plate are located between first interval sleeve and second interval sleeve, first interval sleeve is adjacent to the shaft sleeve in the axial, second interval sleeve is adjacent to the wear plate in the axial. The utility model discloses through the shaft sleeve, wear plate on end cover and the first interval sleeve, second interval sleeve on the pivot act on to limit the axial excursion of pivot, can bear bigger axial force and low cost.

Description

Technical Field

[0001] This utility model relates to the field of power device technology, specifically to an electric motor and an actuator. Background Technology

[0002] Electric motors, as devices for converting electrical energy into mechanical energy, are widely used in our production and daily lives. For example, in electric vehicles, they work in conjunction with the transmission mechanism to act as actuators, driving doors, windows, and other mechanisms. Typically, an electric motor consists of a stator and a rotor that rotates relative to the stator. The rotor's shaft extends outwards and is connected to the load via the transmission mechanism. During operation, the motor shaft experiences significant axial movement due to the load's motion. To address this, some motors incorporate expensive ball bearings in their end caps to limit this axial movement, relying on the friction pair between the outer ring of the ball bearing and the end cap to bear the axial force. However, this design limits the axial force it can withstand and, to some extent, increases the motor's cost. Utility Model Content

[0003] In view of this, the present invention aims to provide a low-cost motor and an actuator having the motor, which can effectively limit the axial movement of its shaft.

[0004] On one hand, this utility model provides an electric motor, including a stator and a rotor rotatably disposed at the center of the stator. The rotor includes a shaft, on which a first spacer sleeve and a second spacer sleeve are fixedly disposed. An end cover is disposed at the side end of the stator. A first receiving hole is provided on one axial side of the end cover, and a bushing sleeve is disposed in the first receiving hole. A wear-resistant plate is provided on the other axial side of the end cover. The bushing sleeve and the wear-resistant plate are located between the first spacer sleeve and the second spacer sleeve. The first spacer sleeve is axially adjacent to the bushing sleeve, and the second spacer sleeve is axially adjacent to the wear-resistant plate.

[0005] The motor may exhibit one or more of the following features, either individually or in combination.

[0006] In some embodiments, the end cap is an injection molded part, the end cap has a second receiving hole on the side where the wear-resistant plate is located, the wear-resistant plate is disposed in the second receiving hole, and the end cap has an integrally formed partition between the first receiving hole and the second receiving hole, the partition forming the bottom wall of the first receiving hole and the second receiving hole.

[0007] In some embodiments, the wear-resistant plate is an oil-containing porous component; or the wear-resistant plate is a plate-shaped component made of one or more of polytetrafluoroethylene, nylon, engineering plastics or polyoxymethylene as the matrix and graphite, molybdenum disulfide, glass fiber as the filler.

[0008] In some embodiments, the oil-impregnated porous component is an oil-impregnated powder metallurgy sintered component.

[0009] In some embodiments, the wear-resistant plate is an oil-impregnated iron-copper powder metallurgy sintered part.

[0010] In some embodiments, the first spacer sleeve and the second spacer sleeve are metal powder sintered parts.

[0011] In some embodiments, a first washer is provided between the first spacer sleeve and the bushing, and a second washer is provided between the second spacer sleeve and the wear-resistant plate.

[0012] In some embodiments, the bushing and the wear-resistant plate are tightly fitted and fixed in the end cover, and there is a gap between the wear-resistant plate and the rotating shaft. The first spacer sleeve and the second spacer sleeve are tightly fitted and fixed on the rotating shaft.

[0013] In some embodiments, the outer peripheral wall of the wear-resistant plate is non-circular and is stopped by the end cap.

[0014] In some embodiments, the axial gap between the components between the first spacer sleeve and the second spacer sleeve is not greater than 0.15 mm.

[0015] In some embodiments, when the wear-resistant plate rotates relative to the first washer, an oil film layer is formed between the contact surfaces of the two.

[0016] On the other hand, this utility model provides an actuator, including the aforementioned motor and a speed reduction transmission mechanism connected to the rotating shaft of the motor.

[0017] Compared with the prior art, the actuator and motor provided by this utility model have bushings and wear-resistant plates respectively arranged on both axial sides of the end cover, which interact with the first spacer sleeve and the second spacer sleeve on the rotating shaft to limit the axial movement of the rotating shaft; the end cover is an injection molded part and a partition is formed between the bushing sleeve and the wear-resistant plate to withstand the axial impact of the rotating shaft, which can withstand a large axial force and has low cost. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of one embodiment of the motor of this utility model.

[0019] Figure 2 for Figure 1 The top view of the motor shown.

[0020] Figure 3 for Figure 2 Sectional view along line II-II.

[0021] Figure 4 for Figure 1 The exploded view of the motor shown.

[0022] Figure 5 for Figure 4 The exploded view of the end cover of the motor shown.

[0023] Figure 6 for Figure 5 Another perspective view.

[0024] Figure 7 for Figure 3 A magnified view of center circle VIII.

[0025] Figure 8 This is a schematic diagram of another state of the motor of this utility model.

[0026] Explanation of icon numbers:

[0027] 100. Electric motor;

[0028] 20. Stator; 22. Stator housing; 24. Permanent magnet; 26. Shaft hole; 28. Sliding bearing;

[0029] 30. Rotor; 32. Shaft; 321. First spacer sleeve; 323. Second spacer sleeve; 325. First washer; 327. Second washer; 34. Iron core; 36. Commutator;

[0030] 40. End cap; 41. First receiving hole; 42. Bushing; 43. Second receiving hole; 44. Wear-resistant plate; 45. Partition plate; 46. Cover plate; 47. Perforation; 48. Seal; 49. Brush;

[0031] 50. Circuit board; 52. Magnetic ring. Detailed Implementation

[0032] To facilitate understanding of this utility model, a more comprehensive description will be provided below with reference to the accompanying drawings. One or more embodiments of this utility model are exemplarily shown in the drawings to enable a more accurate and thorough understanding of the disclosed technical solutions. However, it should be understood that this utility model can be implemented in many different forms and is not limited to the embodiments described below.

[0033] This invention provides an electric motor and an actuator using the electric motor, which can be used in vehicles to drive load movement or rotation, such as in electric vehicles to drive door opening and closing, window raising and lowering, and multi-directional seat adjustment.

[0034] Figure 1 This is a schematic diagram of a specific embodiment of the motor of this utility model. The motor 100 is preferably a permanent magnet direct current (PMDC) motor, which has advantages such as small size, high efficiency, and simple structure. Figure 1-4As shown, the motor 100 includes a stator 20 and a rotor 30 rotatably disposed at the center of the stator 20; a transmission mechanism, such as a worm gear, rack and pinion, etc., can be connected between the rotor 30 and the load (such as a car door, window, or seat). This mechanism can adjust the relationship between the rotational speed and torque, change the transmission direction, optimize power distribution, etc., to match the motor's performance with the load requirements, allowing the load to rotate or move at an appropriate speed. The specific structure of the transmission mechanism can refer to the relevant structures of existing actuators, and will not be elaborated here.

[0035] like Figure 3-6 As shown, the stator 20 includes a cylindrical stator shell 22 and an annular permanent magnet or multiple tile-shaped permanent magnets 24 attached to the inner wall of the stator shell 22. The rotor 30 is disposed in the center of the stator 20 and includes a shaft 32, an iron core 34 sleeved on the shaft 32, and multiple coils (not shown) wound on the iron core 34. When the coils are energized, they generate a periodically changing magnetic field, which interacts with the magnetic field of the permanent magnets 24 of the stator 20, driving the rotor 30 to rotate continuously. The transmission mechanism is connected to the shaft 32 of the rotor 30, driving the load to rotate or move at an appropriate speed.

[0036] In this embodiment, one end of the stator housing 22 is open to facilitate the assembly of the rotor 30, etc. An end cap 40 covers and closes the open end of the stator housing 22, and the outer end of the rotating shaft 32 (e.g., Figure 3 The top portion (as shown) extends outward through end cap 40 and connects to the transmission mechanism. Please also refer to... Figure 3 and Figure 6 The end cap 40 is preferably made of low-cost plastic, and a first receiving hole 41 is formed in the center of its inner side (the side facing the stator housing 22), and a bushing 42 is installed in the first receiving hole 41. The bushing 42 can be fixed in the first receiving hole 41 by means of interference fit or other means to support the rotation of the rotating shaft 32.

[0037] like Figure 3 and Figure 5As shown, a second receiving hole 43 is formed in the center of the outer side of the end cap 40 (the side facing away from the stator housing 22). A wear-resistant plate 44 is installed in the second receiving hole 43. The outer peripheral wall of the wear-resistant plate 44 is non-circular to allow for a stop connection with the inner wall of the second receiving hole 43. Alternatively, it can be fixedly installed in the second receiving hole 43 by other means such as interference fit, bonding, welding, or snap-fit, ensuring a stable fit between the wear-resistant plate 44 and the end cap 40. The wear-resistant plate 44 is an oil-impregnated porous part, such as an oil-impregnated powder metallurgy sintered part. Preferably, it is a sintered porous structure, such as iron-copper powder metallurgy sintered part, with oil injected into the internal pores under pressure. The wear-resistant plate 44 can be oiled by machining the internal pores. Alternatively, it can be a plate-shaped part made of a material with self-lubricating properties, such as a matrix of polytetrafluoroethylene, nylon, engineering plastics, or polyoxymethylene, and fillers of graphite, molybdenum disulfide, or glass fiber. The wear-resistant plate 44 has the structural strength to prevent deformation and damage under impact, the wear resistance to meet the operating requirements of the motor, the lubrication performance to reduce wear on the grinding parts and friction noise, and the ability to quickly transfer frictional heat when the motor rotates at high speed.

[0038] like Figure 5 and Figure 6 As shown, the end cap 40 forms an annular partition 45 between the first receiving hole 41 and the second receiving hole 43. The partition 45 protrudes radially inward relative to the walls of the first receiving hole 41 and the second receiving hole 43, with an inner diameter slightly larger than the outer diameter of the rotating shaft 32, forming the bottom wall of the first receiving hole 41 and the second receiving hole 43. During assembly, the outer end of the rotating shaft 32 sequentially passes through the bushing 42, the partition 45, and the wear-resistant plate 44. Preferably, the rotating shaft 32 is clearance-fitted with the bushing 42, the partition 45, and the wear-resistant plate 44.

[0039] like Figure 4 , Figure 7-8 As shown, a first spacer sleeve 321 and a second spacer sleeve 323 are spaced apart on the rotating shaft 32. The first spacer sleeve 321 is located on the side of the bushing 42 opposite to the partition plate 45 and adjacent to the bushing 42. The second spacer sleeve 323 is located on the side of the wear-resistant plate 44 opposite to the partition plate 45 and adjacent to the wear-resistant plate 44. Preferably, the first spacer sleeve 321 and the second spacer sleeve 323 can be made of sintered metal powder, such as stainless steel powder, and are fixedly connected to the rotating shaft 32 by means of interference fit or other methods, so that they can rotate synchronously with the rotating shaft 32.

[0040] In one embodiment, the first spacer sleeve 321 has a first washer 325 disposed on its side facing the bushing 42, and the second spacer sleeve 323 has a second washer 327 disposed on its side facing the wear-resistant plate 44. The first washer 325 and the second washer 327 can be separately formed sheets, and can be flat washers or corrugated washers, used to adjust the gap between components and ensure assembly accuracy.

[0041] like Figure 3 , Figure 5 As shown, a circuit board 50 is provided on the outer side of the end cover 40 (i.e., the side opposite to the stator housing 22) for connecting an external power supply to power the coils of the rotor 30. Preferably, a Hall sensor is provided on the circuit board 50, and a magnetic ring 52 is fixedly sleeved on the rotating shaft 32 and corresponds to the Hall sensor. By sensing the change in the magnetic field of the magnetic ring 52 by the Hall sensor, the position of the rotor 30 can be determined, thereby controlling the operation of the motor 100.

[0042] like Figure 4-5 As shown, a cover plate 46 is provided on the side of the end cover 40 away from the motor housing 22. The cover plate 46 seals the end cover 40 to prevent external moisture, dust, etc. from entering the end cover and affecting electrical safety. A through hole 47 is provided in the center of the cover plate 46 for the shaft 32 to pass through to connect to the transmission mechanism or load. Preferably, a sealing element 48 is provided on the outer side of the cover plate 46 at the position corresponding to the through hole 47 to block the through hole 47.

[0043] like Figure 3 As shown, the stator housing 22 has a shaft hole 26 formed in the center of its side opposite to the end cover 40, and a sliding bearing 28 is disposed in the shaft hole 26. In this way, the two ends of the rotating shaft 32 are supported by the sliding bearing 28 and the bushing 42 respectively, which improves the coaxiality and makes the rotation of the rotor 30 more stable.

[0044] like Figure 3-4 as well as Figure 6 As shown, the motor 100 can be a brushed motor, with brushes 49 disposed on the inner side of its end cover 40 (i.e., the side facing the stator housing 22). The terminals of the brushes 49 pass through the end cover 40 and are electrically connected to the circuit board 50. A commutator 36 is disposed on the rotating shaft 32, and the commutator 36 has multiple commutator segments, each of which is electrically connected to a coil. During the rotation of the rotor 30, the brushes 49 sequentially contact or separate from each commutator segment, causing the corresponding coil to be energized or de-energized, thereby generating a periodically changing magnetic field.

[0045] like Figure 7As shown, during motor operation, when the shaft 32 moves axially, the first spacer sleeve 321 may occasionally touch the bushing 42 through the first washer 325, preventing the shaft 32 from moving further upward. Because the bushing 42 is an oil-impregnated bearing, even if the first washer 325 rubs against the bushing 42, lubricating oil will seep out from the holes of the bushing 42, forming a continuous oil film on the contact surface to prevent dry friction and thus not affect the rotation of the rotor. Or, as... Figure 8 As shown, the second spacer 323 may occasionally touch the wear-resistant plate 44 through the second washer 327, preventing the shaft 32 from moving further downward. Because the wear-resistant plate 44 is an oil-impregnated sintered powder metallurgy part, during actual use, the rapid rotation of external components such as the second washer 327 generates negative pressure, causing the lubricating oil inside the wear-resistant plate 44 to flow out onto the lubrication contact surface. When the second washer 327 stops rotating, the lubricating oil is drawn back into the pores. Even if the second washer 327 rubs against the wear-resistant plate 44, the lubricating oil will seep out from the pores of the wear-resistant plate 44, forming a continuous oil film on the contact surface to prevent dry friction and thus not affect the rotor's rotation. This effectively limits the axial movement of the shaft 32 and ensures the normal operation of the motor.

[0046] When the rotating shaft 32 moves up and down along the axial direction, its axial impact force is transmitted to the partition 45 through the bushing 42 or the wear-resistant plate 44. The partition 45 is preferably integrally formed with the end cover 40 and has a certain axial thickness T. The axial thickness T of the partition 45 can be set according to the axial impact force that needs to be withstood. The greater the axial impact force, the greater the thickness of the partition 45. As a rigid load-bearing structure, the axial partition 45 can directly bear axial force through its own material strength and structural dimensions (such as thickness and contact area). Compared with the existing technology that relies on the friction pair between the outer ring of the ball bearing and the end cover, it can break through the upper limit of friction and bear greater axial force. With the rigid positioning of the partition 45 and the lubrication function of the sintered wear-resistant plate 44, the total clearance between the components between the first spacer sleeve 323 and the second spacer sleeve 325, i.e., the axial play, can be stably controlled. It is mainly the sum of the axial clearance H1 between the first spacer sleeve 321 and the bushing 42 and the axial clearance H2 between the second spacer sleeve 323 and the wear-resistant plate 44, which can reduce it to 0.15mm or even less than 0.1mm, reduce shaft movement, and improve running accuracy and stability.

[0047] This application can effectively limit the axial movement of the motor shaft 32 by cooperating with the spacer sleeves 321 and 323, the bushing 42, and the wear plate 44. The wear plate 44 is made of oil-containing porous parts or materials with self-lubricating properties. The materials are inexpensive and the manufacturing process is simple, which can effectively reduce costs compared to using ball bearings. At the same time, the end cover 40 is injection molded and integrally formed into the partition 45, which can not only withstand greater axial forces, but also further reduce the cost of the motor 100.

[0048] It should be noted that the above embodiments only illustrate preferred embodiments of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the present invention. It should be pointed out that those skilled in the art can make several modifications and improvements without departing from the concept of the present invention, such as combining different features in various embodiments, and these should all fall within the protection scope of the present invention.

Claims

1. An electric motor comprising a stator and a rotor rotatably disposed at the center of the stator, the rotor including a shaft, on which a first spacer sleeve and a second spacer sleeve are fixedly disposed, characterized in that, The stator is provided with an end cap on one side, and a first receiving hole is provided on one axial side of the end cap. A bushing is provided in the first receiving hole, and a wear-resistant plate is provided on the other axial side of the end cap. The bushing and the wear-resistant plate are located between the first spacer sleeve and the second spacer sleeve. The first spacer sleeve is axially adjacent to the bushing sleeve, and the second spacer sleeve is axially adjacent to the wear-resistant plate.

2. The motor as described in claim 1, characterized in that, The end cap is an injection molded part. The end cap has a second receiving hole on the side where the wear-resistant plate is located. The wear-resistant plate is disposed in the second receiving hole. The end cap has an integrally formed partition between the first receiving hole and the second receiving hole. The partition forms the bottom wall of the first receiving hole and the second receiving hole.

3. The motor as described in claim 1, characterized in that, The wear-resistant plate is an oil-containing porous component; or the wear-resistant plate is a plate-shaped component made of one or more of polytetrafluoroethylene, nylon, engineering plastics or polyoxymethylene as the matrix and graphite, molybdenum disulfide, glass fiber as the filler.

4. The motor as described in claim 3, characterized in that, The oil-impregnated porous component is an oil-impregnated powder metallurgy sintered component.

5. The motor as described in claim 4, characterized in that, The wear-resistant plate is an oil-impregnated iron-copper powder metallurgy sintered part.

6. The motor as described in claim 1, characterized in that, The first spacer sleeve and the second spacer sleeve are metal powder sintered parts.

7. The motor as described in claim 1, characterized in that, A first washer is provided between the first spacer sleeve and the bushing, and a second washer is provided between the second spacer sleeve and the wear-resistant plate.

8. The motor as described in claim 1, characterized in that, The bushing and wear-resistant plate are tightly fitted and fixed in the end cover. There is a gap between the wear-resistant plate and the rotating shaft. The first spacer sleeve and the second spacer sleeve are tightly fitted and fixed on the rotating shaft.

9. The motor as described in claim 8, characterized in that, The outer peripheral wall of the wear-resistant plate is non-circular and is fixedly connected to the end cap.

10. The motor as described in claim 9, characterized in that, The axial clearance between the components between the first spacer sleeve and the second spacer sleeve is no greater than 0.15 mm.

11. The motor as described in claim 7, characterized in that, When the wear-resistant plate rotates relative to the first washer, an oil film layer is formed between the contact surfaces of the two.

12. An actuator, characterized in that, It includes the motor as described in any one of claims 1-11 and the speed reduction transmission mechanism connected to the rotating shaft of the motor.

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