Rotating structure of electric compressor

Abstract

The present invention relates to a rotating structure of an electric compressor, comprising: a motor housing having a main bearing and an auxiliary bearing mounted at both ends of the central axis thereof; the crankshaft and the motor shell are coaxially arranged, the two ends of the crankshaft in the axis direction are installed on the main bearing and the auxiliary bearing respectively, and the two axial ends of the crankshaft are in clearance fit with bearing inner rings of the main bearing and the auxiliary bearing in the radial direction; the motor rotor is mounted on the crankshaft, and the motor rotor synchronously rotates along with the crankshaft; and the motor stator is arranged in the motor shell and between the motor stator and the motor rotor. According to the rotating structure of the electric compressor, rigid connection between the crankshaft and the main bearing is changed into clearance connection and elastic connection, a transmission route of operation vibration of the motor is cut off, and therefore the vibration performance of the compressor is improved. And meanwhile, under the action of magnetic force, the rotor iron core and the stator iron core can be completely aligned in the axial direction, so that the operation noise and vibration of the motor are reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of compressors, and in particular to a rotating structure of an electric compressor. Background Art

[0002] The rotating mechanism of a scroll electric compressor consists of a motor rotor, crankshaft, eccentric sleeve, main bearing, secondary bearing, and a rotating plate assembly. The compressor motor rotor is press-fitted onto the crankshaft, while the stator is fixed within the motor housing. The rotor-crankshaft assembly is press-fitted onto the main bearing. During assembly, the crankshaft passes through the secondary bearing, creating a clearance fit. When the compressor is running, power is supplied to the motor stator through the three-phase terminals. The stator generates a magnetic field, which rotates the permanent magnet rotor. Simultaneously, power is transmitted to the compressor via the crankshaft, which is press-fitted within the rotor.

[0003] However, in actual use, it was found that the compressor had the following disadvantages: Disadvantage 1: The motor rotor and crankshaft, crankshaft and main bearing, main bearing and support plate are all interference fit links. The vibration generated by the motor operation is easily transmitted to the outside world from the motor rotor → crankshaft → main bearing → support plate, affecting the vibration performance of the compressor.

[0004] Disadvantage 2: The motor stator and motor rotor are respectively assembled on the motor housing and crankshaft in an interference fit manner. Due to assembly errors and processing errors, the motor stator core and the motor rotor core are offset in the axial position, resulting in worse motor operation noise and vibration. Summary of the Invention

[0005] To this end, the technical problem to be solved by the present invention is to overcome the problem in the prior art that the assembly structure between the click rotor and the click stator causes vibration during the operation of the motor, affecting the normal operation of the motor.

[0006] In order to solve the above technical problems, the present invention provides a rotating structure of an electric compressor, comprising: a motor housing, with a main bearing and a secondary bearing installed at both ends of the central axis; a crankshaft, which is coaxially arranged with the motor housing, and the two ends of the crankshaft in the axial direction are respectively installed on the main bearing and the secondary bearing, and the axial ends of the crankshaft are radially clearance-fitted with the inner rings of the main bearing and the secondary bearing; a motor rotor, which is installed on the crankshaft, and the motor rotor rotates synchronously with the crankshaft; a motor stator, which is installed in the motor housing, and there is a magnetic force between the motor stator and the motor rotor. The rotating structure of the electric compressor described in the present invention, by changing the rigid connection between the crankshaft and the main bearing into a clearance connection and an elastic connection, cuts off the transmission path of the motor operation vibration, thereby improving the vibration performance of the compressor. At the same time, under the action of the magnetic force, the rotor core and the stator core can be completely aligned in the axial direction, reducing the operating noise and vibration of the motor.

[0007] In one embodiment of the present invention, a first elastic support body is provided between the crankshaft and the inner ring of the main bearing. The first elastic support body is sleeved on the crankshaft and is used to limit the axial direction of one end of the crankshaft.

[0008] In one embodiment of the present invention, a second elastic support body is provided between the crankshaft and the inner ring of the auxiliary bearing, the second elastic support body is sleeved on the crankshaft, and the second elastic support body is used to limit the axial direction of the other end of the crankshaft.

[0009] In one embodiment of the present invention, the crankshaft is in the shape of a cylindrical rod, a limiting boss is provided on the outer wall of the crankshaft near one end of the main bearing, and the first elastic support body is located between the limiting boss and the inner ring of the main bearing.

[0010] In one embodiment of the present invention, a limiting step is provided on the circumferential outer wall of the crankshaft near one end of the auxiliary bearing, and the second elastic support body is located between the limiting step and the inner ring of the auxiliary bearing.

[0011] In one embodiment of the present invention, one end of the crankshaft is elastically matched with the first elastic support body, and the other end of the crankshaft is elastically matched with the second elastic support body.

[0012] In one embodiment of the present invention, the motor rotor is interference-pressed onto the crankshaft.

[0013] In one embodiment of the present invention, the motor stator is interference-mounted in the motor housing.

[0014] In one embodiment of the present invention, the first elastic support body is an O-ring.

[0015] In one embodiment of the present invention, the second elastic support body is an O-ring.

[0016] The above technical solution of the present invention has the following beneficial effects compared with the prior art: The rotating structure of the electric compressor described in the present invention is such that the motor rotor is press-fitted onto the crankshaft with an interference fit, and the crankshaft is placed between the main bearing and the secondary bearing. The crankshaft establishes an elastic connection with the main bearing and the secondary bearing axially through an elastic support body, and radially has a clearance fit with the main bearing and the secondary bearing. The motor generates vibrations during operation as a vibration source, and the vibrations are transmitted to the outside world via the transmission path of the motor rotor → crankshaft → main bearing → support plate. Since the rigid fit between the crankshaft and the main bearing is transformed into an elastic fit and a clearance fit established by the elastic support body, the vibration of the vibration source is absorbed by the elastic deformation of the elastic support body, the vibration transmission path is blocked, and the vibration will not be transmitted to the outside world. Due to the magnetic force between the motors, the stator core and the rotor core are completely aligned during operation, reducing the noise of the motor operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings, wherein Figure 1 is a cross-sectional view of a rotating structure of an electric compressor in a preferred embodiment of the present invention; Figure 2 For the present invention Figure 1 A partial enlarged view of point A in the middle; Figure 3 For the present invention Figure 1 A partial enlarged view of point B in the middle.

[0018] Explanation of the reference numerals in the accompanying drawings in the specification: motor housing 1, main bearing 11, auxiliary bearing 12, crankshaft 2, limiting boss 21, limiting step 22, motor rotor 3, motor stator 4, first elastic support body 5, second elastic support body 6. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0020] Reference Figure 1-3 As shown, the rotating structure of the electric compressor of the present invention includes several main parts: a motor housing 1, a crankshaft 2, a motor rotor 3 and a motor stator 4; the motor housing 1, a main bearing 11 and a secondary bearing 12 are installed at both ends of the central axis of the motor housing 1, and the main bearing 11 and the secondary bearing 12 are respectively installed at the head and tail ends of the motor housing 1; the crankshaft 2 is coaxially arranged with the motor housing 1, and the two end portions of the crankshaft 2 in the axial direction are respectively installed on the main bearing 11 and the secondary bearing 12, and the crankshaft 2, the main bearing 11 and the secondary bearing 12 are kept coaxially arranged, and the axial ends of the crankshaft 2 are radially clearance-fitted with the inner rings of the main bearing 11 and the secondary bearing 12; the motor rotor 3 is installed on the crankshaft 2, and the motor rotor 3 rotates synchronously with the crankshaft 2; the motor stator 4 is installed in the motor housing 1, and there is a magnetic force between the motor stator 4 and the motor rotor 3.

[0021] In the above structure, a first elastic support body 5 is provided between the crankshaft 2 and the inner ring of the main bearing 11. The first elastic support body 5 is sleeved on the crankshaft 2 and is used to define the axial direction of one end of the crankshaft 2. A second elastic support body 6 is provided between the crankshaft 2 and the inner ring of the secondary bearing 12. The second elastic support body 6 is sleeved on the crankshaft 2 and is used to define the axial direction of the other end of the crankshaft 2. One end of the crankshaft 2 is elastically mated with the first elastic support body 5, and the other end of the crankshaft 2 is elastically mated with the second elastic support body 6.

[0022] In the above structure, the crankshaft 2 is in the shape of a cylindrical rod, and a limiting boss 21 is provided on the outer wall of the crankshaft 2 near the main bearing 11. The limiting boss 21 is annular and fixedly arranged on the circumferential outer wall of the crankshaft 2 near the main bearing 11, so that an annular groove is formed between the limiting boss 21 and the inner ring of the main bearing 11. The first elastic support body 5 is located in the annular groove between the limiting boss 21 and the inner ring of the main bearing 11 to provide elastic support for one end of the crankshaft 2.

[0023] In the above structure, a limiting step 22 is provided on the circumferential outer wall of the crankshaft 2 near one end of the auxiliary bearing 12. The limiting step 22 is an annular transition step on the outer circumference of the crankshaft 2, so that an annular groove is formed between the limiting step 22 and the inner ring of the auxiliary bearing 12. The second elastic support body 6 is located in the annular groove between the limiting step 22 and the inner ring of the auxiliary bearing 12 to provide elastic support for the other end of the crankshaft 2.

[0024] Specifically, the motor rotor 3 is press-fitted onto the crankshaft 2 , and the motor stator 4 is installed in the motor housing 1 .

[0025] Specifically, the first elastic support body 5 and the second elastic support body 6 are both O-rings.

[0026] Based on the above structure, the working principle of the rotary structure of the electric compressor of the present invention is as follows: The motor rotor 3 is press-fitted onto the crankshaft 2, and the motor stator 4 is fixed in the motor housing 1. One end of the crankshaft 2 is placed in the auxiliary bearing 12, and the radial clearance fit with the auxiliary bearing 12 is ( Figure 3 The other end of the crankshaft is in the main bearing 11, and has a radial clearance fit with the main bearing 11 ( Figure 2 C in the middle), the axial direction is supported by the first elastic support body 5. The axial and radial degrees of freedom of the crankshaft 2 are not rigidly restricted, which allows the motor rotor 3 and the crankshaft 2 to move slightly in the axial direction during assembly. When the motor is running, due to the magnetic force between the motor stator 4 and the motor rotor 3, the motor rotor core is pulled to move and align with the motor stator core, avoiding axial offset caused by assembly and manufacturing errors, and optimizing the motor operation noise and vibration performance. Since the crankshaft 2 and the main bearing 11 and the auxiliary bearing 12 are clearance fit in the radial direction, and are elastically fit through the first elastic support body 5 and the second elastic support body 6 in the axial direction, the transmission route of the motor rotor 3 operation vibration is blocked (motor rotor → crankshaft → main bearing → housing), and the vibration generated by the motor rotor 3 operation is transmitted to the crankshaft 2 and will no longer be transmitted to other parts, thereby improving the vibration performance of the compressor.

[0027] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A rotating structure of an electric compressor, characterized in that: include: The motor housing has main bearings and auxiliary bearings mounted on both ends of its central axis; A crankshaft is coaxially arranged with the motor housing, and the two ends of the crankshaft in the axial direction are respectively mounted on the main bearing and the auxiliary bearing, and the axial ends of the crankshaft are radially clearance-fitted with the inner rings of the main bearing and the auxiliary bearing; A motor rotor is mounted on the crankshaft and rotates synchronously with the crankshaft; The motor stator is installed in the motor housing, and there is magnetic force between the motor stator and the motor rotor.

2. The rotary structure of the electric compressor according to claim 1, characterized in that: A first elastic support body is provided between the crankshaft and the inner ring of the main bearing. The first elastic support body is sleeved on the crankshaft and is used to limit the axial direction of one end of the crankshaft.

3. The rotating structure of the electric compressor according to claim 2, characterized in that: A second elastic support body is provided between the crankshaft and the inner ring of the auxiliary bearing. The second elastic support body is sleeved on the crankshaft and is used to limit the axial direction of the other end of the crankshaft.

4. The rotating structure of the electric compressor according to claim 3, characterized in that: The crankshaft is in the shape of a cylindrical rod. A limiting boss is provided on the outer wall of the crankshaft near one end of the main bearing. The first elastic support body is located between the limiting boss and the inner ring of the main bearing.

5. The rotating structure of the electric compressor according to claim 3 or 4, characterized in that: A limiting step is provided on the circumferential outer wall of the crankshaft near one end of the auxiliary bearing, and the second elastic support body is located between the limiting step and the inner ring of the auxiliary bearing.

6. The rotating structure of the electric compressor according to claim 5, characterized in that: One end of the crankshaft is elastically matched with the first elastic support body, and the other end of the crankshaft is elastically matched with the second elastic support body.

7. The rotating structure of the electric compressor according to claim 1, characterized in that: The motor rotor is interference-pressed onto the crankshaft.

8. The rotating structure of the electric compressor according to claim 7, characterized in that: The motor stator is interference-mounted in the motor housing.

9. The rotating structure of the electric compressor according to claim 1, characterized in that: The first elastic support body is an O-ring.

10. The rotating structure of the electric compressor according to claim 9, characterized in that: The second elastic support body is an O-ring.

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