Scroll compressor

Abstract

The present application provides a scroll compressor, which comprises a housing, a scroll mechanism, a motor driving the scroll mechanism through a driving shaft, and a bearing seat in which a first bearing and a second bearing are arranged and which are arranged on one side of the motor in an axial direction to support the driving shaft, wherein the motor and the bearing seat are accommodated inside the housing, and the scroll compressor further comprises a first balance block matched with the driving shaft, and the bearing seat, the first bearing and the second bearing constitute a first cavity in which the first balance block is located. According to the present application, the load on the bearing of the scroll compressor is significantly reduced, thereby prolonging the service life of the bearing and the compressor.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of compressors, and more particularly, to a cantilever scroll compressor and a balance weight configuration for the cantilever scroll compressor. BACKGROUND

[0002] This section provides background information which is not necessarily prior art.

[0003] Scroll compressors generally include a scroll mechanism composed of a fixed scroll member and an orbiting scroll member. The orbiting scroll member is supported by a main bearing housing to provide axial constraint and performs a translational rotation relative to the fixed scroll member under the drive of an eccentric member. During the operation of the scroll compressor, centrifugal force or centrifugal moment generated by the rotation of the eccentric member can cause vibration of the compressor. A balance weight is usually provided on the rotating member, such as the upper end of the drive shaft, to provide a counteracting centrifugal force or centrifugal moment to balance the unbalance amount generated by the eccentric member.

[0004] In the existing cantilever scroll compressor, on the one hand, since the bearing set is arranged on one side of the motor, the axial spacing of the two bearings in the bearing set is small, and the mass of the balance weight arranged on the drive shaft is large, which causes a large load on the bearings, affecting the service life of the bearings and the compressor; on the other hand, since the balance weight stirs the lubricating oil when the scroll compressor is running, additional power loss is generated and the oil circulation control of the compressor is adversely affected.

[0005] Therefore, it is necessary to provide an improved scroll compressor to improve the service life of the bearings and the compressor and improve the performance of the compressor. SUMMARY

[0006] This section provides a general summary of the application, and not a comprehensive disclosure of the full scope or all the features of the application.

[0007] The purpose of the present application is to provide a scroll compressor which reduces the load on the bearings and effectively controls oil circulation, and in particular, a cantilever scroll compressor which has higher assembly precision, lower noise and better performance.

[0008] According to one aspect of the present application, a scroll compressor is provided, which includes a housing, a scroll mechanism, a motor driving the scroll mechanism through a drive shaft, and a bearing housing in which a first bearing and a second bearing are arranged, the first bearing and the second bearing being arranged on one side of the motor in an axial direction to support the drive shaft, wherein the motor and the bearing housing are accommodated inside the housing, and the scroll compressor further includes a first balance weight coupled with the drive shaft, the bearing housing, the first bearing and the second bearing configuring a first cavity, and the first balance weight being located in the first cavity.

[0009] Optionally, the bearing seat is an integrated bearing seat.

[0010] Optionally, the first bearing is closer to the scroll mechanism than the second bearing, and the first balance block has a maximum lateral radial dimension that is smaller than a lateral radial dimension of the first bearing.

[0011] Optionally, the first cavity has a radial dimension that is equal to or slightly greater than a maximum lateral radial dimension of the first balance block.

[0012] Optionally, the first cavity has an axial height that is equal to or slightly greater than an axial height of the first balance block.

[0013] Optionally, the bearing seat includes a bearing arrangement portion, a thrust portion, and an extension portion, the second bearing is arranged at the bearing arrangement portion, the thrust portion supports the scroll mechanism, the extension portion extends from the bearing arrangement portion to the thrust portion, a second cavity for accommodating the first bearing and a portion of the scroll mechanism is formed inside the thrust portion, and the first cavity is formed inside the extension portion.

[0014] Optionally, the first cavity has a radial dimension that is smaller than a radial dimension of the second cavity.

[0015] Optionally, a step portion is arranged between an inner wall of the thrust portion and an inner wall of the extension portion, and the first bearing is arranged at the step portion.

[0016] Optionally, the first balance block is arranged substantially centrally in the axial direction between the first bearing and the second bearing.

[0017] Optionally, the scroll compressor further includes a second balance block, and the second balance block is arranged on an opposite side of the motor from the first balance block.

[0018] In general, according to the bearing seat and the balance block of the scroll compressor of the present application, the axial spacing between the two bearings in the bearing set can be effectively increased, thereby reducing the load on the bearings and improving the service life of the bearings and the compressor. Since the balance block is arranged inside the bearing seat, the internal space of the compressor can be effectively utilized, and the agitation of the lubricating oil by the balance block can be significantly reduced, thereby reducing power loss, effectively controlling oil circulation of the compressor, and optimizing the vibration and noise problems of the compressor. In addition, in combination with the integrated design of the bearing seat, the assembly precision of the compressor is further improved, thereby improving the performance of the compressor. BRIEF DESCRIPTION OF DRAWINGS

[0019] The foregoing and other features and characteristics of the present application will become more apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example only the principles of the application. The same reference signs in the drawings indicate the same components. In the drawings:

[0020] Figure 1 A longitudinal sectional view of a scroll compressor according to an embodiment of the present application is shown.

[0021] Figure 2 An enlarged detail view of a portion A in Figure 1 is shown;

[0022] Figure 3 A longitudinal sectional view of a scroll compressor according to a first comparative example is shown; and

[0023] Figure 4 A longitudinal sectional view of a scroll compressor according to a second comparative example is shown. DETAILED DESCRIPTION

[0024] The application will now be described in detail with reference to the accompanying drawings. Figures 1 to 4 A preferred embodiment of the present application will be described in detail. The following description is merely exemplary in nature and is not intended to limit the present application and its applications or uses. Throughout the drawings, corresponding or like components or parts are denoted by like reference numerals.

[0025] Reference will now be made to Figure 1 The overall configuration of the scroll compressor according to the embodiment of the present application will be described. As shown in Figure 1 , the scroll compressor 10a includes a housing 6, a scroll mechanism composed of a fixed scroll member 7 and an orbiting scroll member 8, a bearing housing 1a, a motor 9 and a drive shaft 11 for driving the scroll mechanism, etc., wherein the bearing housing 1a, the motor 9 and the drive shaft 11 are all disposed in an inner space surrounded by the housing 6. The orbiting scroll member 8 includes an end plate, a hub portion formed on one side of the end plate, and scroll blades formed on the other side of the end plate. One end of the drive shaft 11 is provided with an eccentric crank pin, and an unloading bushing is provided between the eccentric crank pin and the hub portion of the orbiting scroll member 8. The orbiting scroll member 8 is translated relative to the fixed scroll member 7 (i.e., the central axis of the orbiting scroll member 8 rotates around the central axis of the fixed scroll member 7, but the orbiting scroll member 8 itself does not rotate around its own central axis) to achieve compression of fluid by driving the drive shaft 11 with the motor 9. In particular, in a cantilever type scroll compressor as shown in Figure 1 , the side of the orbiting scroll member 8 provided with the hub portion is supported by the bearing housing 1a. The bearing housing 1a is provided with a bearing set including a first bearing 2 and a second bearing 3. The first bearing 2 and the second bearing 3 are arranged in an axial direction on one side of the motor 9 (shown as the upper side of the motor 9 in Figure 1 ), thereby supporting the drive shaft 11. The first bearing 2 is generally located closer to the scroll mechanism relative to the second bearing 3, for example, at the end of the drive shaft 11, while the second bearing 3 is generally located closer to the motor 9 relative to the first bearing 2.

[0026] During the operation of a scroll compressor, the centrifugal force or torque generated by the rotation of the eccentric component can cause compressor vibration. Typically, a counterweight can be installed on the rotating component to provide a counter-centrifugal force or torque to balance the imbalance generated by the eccentric component. For example, the counterweight can be mounted on the drive shaft, on the unloading bushing, or integrated with the unloading bushing. Figure 1 The diagram shows a first balancing block 4a and a second balancing block 5 used to balance torque. The first balancing block 4a is arranged on one side (upper side) of the motor 9 and connected to the drive shaft 11, while the second balancing block 5 is arranged on the opposite side (lower side) of the motor 9. Furthermore, the first balancing block 4a is housed in a first cavity 12 formed by the bearing housing 1a, the first bearing 2, and the second bearing 3, which is axially located between the first bearing 2 and the second bearing 3.

[0027] Specifically, such as Figure 2 As shown, the bearing housing 1a includes a thrust portion 15a, an extension portion 16a, and a bearing mounting portion 18a. The thrust portion 15a can be constructed in a generally annular shape, with a thrust surface on its upper end face that abuts against the side of the end plate of the moving scroll member 8 where a hub is provided, for supporting the moving scroll member 8. The thrust surface can be formed on the upper end face of the thrust portion 15a, or it can be formed separately from the thrust portion 15a. The inner side of the thrust portion 15a also has a generally cylindrical second cavity 14 for accommodating and mounting the hub of the moving scroll member 8, the first bearing 2, and a part of the drive shaft 11. The bearing mounting portion 18a can also be constructed in a generally annular shape, with a central hole formed in its center for the drive shaft 11 to pass through. The second bearing 3 is disposed in the bearing mounting portion 18a around the central hole, thereby supporting the drive shaft 11 mounted in the central hole. The extension 16a is configured to extend from the thrust portion 15a toward the bearing mounting portion 18a, and can be configured as a generally frustum-shaped cone, with a generally cylindrical first cavity 12 formed on its inner side for accommodating the first counterweight 4a and a portion of the drive shaft 11. The radial dimension of the first cavity 12 is smaller than the radial dimension of the second cavity 14. That is, a step portion 17a is formed between the inner wall of the thrust portion 15a and the inner wall of the extension 16a, the first bearing 2 is arranged at this step portion 17a, above the first cavity 12, and the second bearing 3 is arranged at the bearing mounting portion 18a, below the first cavity 12. Preferably, the first bearing 2 is a rolling bearing, and the second bearing 3 is a sliding bearing.

[0028] In scroll compressors, especially in cantilever scroll compressors where the first and second bearings are located on the same side of the motor, the mass of the first balance block is typically large. If the axial distance between the first bearing 2 and the second bearing 3 is small, the load on the bearings will be greater, which will affect the service life of both the bearings and the compressor. For example, Figure 3 andFigure 4 A scroll compressor 10 according to a first comparative example and a scroll compressor 10' according to a second comparative example are shown respectively, wherein the scroll compressors 10, 10' each comprise a housing 6, a scroll mechanism composed of a fixed scroll member 7 and an orbiting scroll member 8, a bearing housing 1, a motor 9 and a drive shaft 11 for driving the scroll mechanism, etc. The bearing housing 1 is provided with a first bearing 2 and a second bearing 3, and only a second cavity 14 is formed in the bearing housing 1. As shown in the first comparative example, the first cavity 14 contains a hub portion of the orbiting scroll member 8, the first balance weight 4, the first bearing 2 and a portion of the drive shaft 11, and the first balance weight 4 is arranged above the first bearing 2. Due to the need to leave space for installing the first balance weight 4 above the first bearing 2, the axial spacing between the first bearing 2 and the second bearing 3 is small. Figure 3 As shown in the second comparative example, the second cavity 14 contains the hub portion of the orbiting scroll member 8, the first bearing 2 and a portion of the drive shaft 11, and the first balance weight 4 is arranged immediately above the motor 9. Due to the need to leave space for installing the first balance weight 4 below the second bearing 3, the axial spacing between the first bearing 2 and the second bearing 3 is also small. Figure 4 As shown in the second comparative example, the second cavity 14 contains the hub portion of the orbiting scroll member 8, the first bearing 2 and a portion of the drive shaft 11, and the first balance weight 4 is arranged immediately above the motor 9. Due to the need to leave space for installing the first balance weight 4 below the second bearing 3, the axial spacing between the first bearing 2 and the second bearing 3 is also small.

[0029] It can be known from the analysis of the force bearing of the bearing set of the scroll compressor according to the first comparative example and the scroll compressor according to the present application that, in the case that the eccentric load borne by the drive shaft is the same, the balance moment provided by the first bearing and the second bearing is also the same, and then if the axial spacing between the first bearing and the second bearing is small, the load borne by the first bearing and the second bearing is large. In the present application, the axial spacing between the first bearing and the second bearing is larger than that in the first comparative example, so that the load on the first bearing and the second bearing is smaller than that in the first comparative example, thereby being beneficial to the reliability and service life of the bearings. According to the test results, compared with the first comparative example, the load on the first bearing 2 in the bearing set of the scroll compressor according to the present application is reduced by 25%, and the load on the second bearing 3 is reduced by 50%.

[0030] Similarly, compared with the second comparative example, since the first balance weight 4a of the present application is arranged between the first bearing and the second bearing, the axial spacing between the first bearing and the second bearing is significantly increased, and the load borne by the first bearing and the second bearing is reduced, thereby improving the service life of the bearings and the compressor. Preferably, the first balance weight 4a is arranged substantially centrally between the first bearing 2 and the second bearing 3 in the axial direction, thereby further reducing the load borne by the first bearing 2 and the second bearing 3.

[0031] Preferably, in this invention, the bearing housing 1a is constructed as a single, integrally formed bearing housing. The first cavity 12 can be defined as a cavity jointly enclosed by the extension 16a of the bearing housing 1a, the first bearing 2, and the second bearing 3. On the one hand, compared to a split design, the integrally formed bearing housing 1a reduces the accumulation of tolerances and the use of fasteners during the assembly process, resulting in better alignment of the two bearings in the bearing housing 1a, higher compressor assembly accuracy, thereby improving compressor performance and reducing vibration and noise. For example, in a split bearing housing where the extension and bearing mounting portion are connected by fasteners, three tolerances will accumulate during the installation process of the split bearing housing, while the integral bearing housing of this invention has only one tolerance during installation. The tolerance of the integral bearing housing can be only one-quarter of the cumulative tolerance of the split bearing housing.

[0032] On the other hand, the first cavity 12 is formed as a smaller and relatively closed cavity. Compared with a completely open space, there is less lubricating oil in the first cavity 12. The first balance block 4a is installed in the first cavity 12, which can reduce the agitation of the lubricating oil during compressor operation and effectively control the compressor oil circulation. The lubricating oil operation process in the scroll compressor 10a will be described in detail below.

[0033] exist Figure 1 In the scroll compressor 10a shown, lubricating oil is typically stored at the bottom of the housing 6. Correspondingly, a channel (not shown in the figure) extending generally axially is formed in the drive shaft 11, extending upwards from a central hole formed at the lower end of the drive shaft 11 to an eccentric hole at the end face of the eccentric crankpin. The end of the central hole is immersed in the lubricating oil at the bottom of the housing 6 or is otherwise supplied with lubricating oil. During compressor operation, lubricating oil is supplied to one end of the central hole. The lubricating oil entering the central hole is pumped or thrown into the eccentric hole by centrifugal force during the rotation of the drive shaft 11 and flows upwards along the eccentric hole until it reaches the end face of the eccentric crankpin. The lubricating oil discharged from the end face of the eccentric crankpin flows downwards along the gap between the unloading bushing and the eccentric crankpin, and the gap between the unloading bushing and the hub, to the second cavity 14 of the bearing housing 1a and lubricates the first bearing 2. Some of the lubricating oil flows downwards through the first bearing 2 to the first cavity 12. In other words, the second cavity 12 contains less lubricating oil compared to the open space or the second cavity 14. This is because the balance block agitates the lubricating oil as the drive shaft rotates during compressor operation, resulting in additional power loss. Figure 3 Compared to the arrangement of the first balance block 4 within the second cavity 14 shown in the previous invention, in this invention, the first balance block 4a is arranged within the first cavity 12, which has less lubricating oil. This effectively reduces the agitation of the lubricating oil by the first balance block 4a, thereby reducing power loss. Furthermore, compared to... Figure 4The first balance block 4 is arranged outside the bearing housing 1a (i.e. in an open space) as shown, but in the present application, the first balance block 4a rotates inside the bearing housing 1a, which can greatly reduce the lubricating oil outside the bearing housing 1a from being atomized in the casing 6 due to the rotation of the balance block, thereby avoiding too much lubricating oil from entering the scroll mechanism, so as to effectively control the lubricating oil circulation and improve the performance of the compressor. Furthermore, since the first balance block 4a is arranged inside the bearing housing 1a in the present application, the internal space of the compressor is more effectively utilized, so that the structure of the compressor is more compact, thereby reducing the vibration and noise of the compressor and improving the performance of the compressor.

[0034] Referring to the drawings Figure 1 and Figure 2 The installation of the bearing housing 1a and the balance block 4a in the present application will be described. First, the second bearing 3 is installed in the bearing housing 1a, and the drive shaft 11 passes through the first cavity 12 and the second cavity 14 of the bearing housing 1a, thereby forming the support of the second bearing 3 to the drive shaft 11. Then, the first balance block 4a is installed in the first cavity 12 from above through the second cavity 14. Generally, the first balance block 4a is configured to include a counterweight portion substantially in the shape of a circular arc and a mounting portion substantially in the shape of a ring for mounting the balance block to the drive shaft, and the counterweight portion extends beyond the mounting portion in the axial direction. Therefore, during the installation of the first balance block 4a, the drive shaft 11 needs to pass through the mounting portion of the first balance block 4a, and then the first balance block 4a is installed into the first cavity 12 along the drive shaft 11 from top to bottom. Finally, the first bearing 2 is installed at the stepped portion 17a of the bearing housing 1a above the first balance block 4a, thereby forming the support of the first bearing 2 to the drive shaft 11.

[0035] In order to achieve the above installation process, the maximum outer radial dimension R1 of the first balance block 4a is smaller than the outer radial dimension R2 of the first bearing 2. Here, the "maximum outer radial dimension" refers to the maximum outer radial dimension of the first balance block 4a in the radial direction. For example, when the first balance block 4a is configured in an irregular shape, i.e. the radial dimensions of the portions of the first balance block 4a along the circumferential direction are different, the outer radial dimension of the portion of the first balance block 4a along the circumferential direction with the largest radial dimension is the maximum outer radial dimension of the first balance block 4a. In addition, preferably, the radial dimension of the first cavity 12 is equal to or slightly larger than the maximum outer radial dimension of the first balance block 4a, and the axial height of the first cavity 12 is equal to or slightly larger than the axial height of the first balance block 4a, so that the first balance block is just accommodated in the first cavity 12, thereby further reducing the size of the second cavity 12, the agitation of the lubricating oil in the first cavity 12 by the first balance block 4a, and saving the internal space of the compressor.

[0036] According to the bearing seat and the balance block provided by the application, the load on the bearing of the cantilever compressor can be effectively reduced, the bearing of the compressor can be centered, the service life of the bearing and the compressor can be prolonged, and the performance of the compressor can be ensured. Meanwhile, the compressor adopting the bearing seat and the balance block is more compact, has high space utilization, and is beneficial to the improvement of the noise and vibration of the compressor.

[0037] The balance block for the scroll compressor and the scroll compressor according to the preferred embodiments of the application are described above in combination with the specific embodiments. It can be understood that the above description is only exemplary but not restrictive, and various modifications and changes can be conceived by those skilled in the art with reference to the above description without departing from the scope of the application. The modifications and changes are also included in the protection scope of the application.

Claims

1. A scroll compressor (10a), comprising: a housing (6); a scroll mechanism; a motor (9) driving the scroll mechanism through a drive shaft (11); a bearing housing (1a) in which a first bearing (2) and a second bearing (3) are arranged, the first bearing (2) and the second bearing (3) being arranged on one side of the motor (9) in an axial direction to support the drive shaft (11); wherein the motor (9) and the bearing housing (1a) are housed inside the housing (6), the bearing housing (1a), the first bearing (2) and the second bearing (3) constituting a first cavity (12), and a first balance weight (4a) is arranged in the first cavity (12) in mating with the drive shaft (11), wherein the bearing housing (1a) comprises a bearing arrangement portion (18a) where the second bearing (3) is arranged, a thrust portion (15a) supporting the scroll mechanism, and an extension portion (16a) extending from the bearing arrangement portion (18a) to the thrust portion (15a), a second cavity (14) for accommodating the first bearing (2) and a part of the scroll mechanism is formed inside the thrust portion (15a), the first cavity (12) is formed inside the extension portion (16a), and no balance weight is arranged in the second cavity (14).

2. The scroll compressor (10a) according to claim 1, characterized in that, The bearing housing (1a) is an integrated bearing housing.

3. The scroll compressor (10a) according to claim 1, characterized in that, The first bearing (2) is closer to the scroll mechanism than the second bearing (3), and a maximum outer radial dimension of the first balance weight (4) is smaller than an outer radial dimension of the first bearing (2).

4. The scroll compressor (10a) according to any one of claims 1 to 3, characterized in that, A radial dimension of the first cavity (12) is equal to or slightly greater than a maximum outer radial dimension of the first balance weight (4a).

5. The scroll compressor (10a) according to any one of claims 1 to 3, characterized in that, An axial height of the first cavity (12) is equal to or slightly greater than an axial height of the first balance weight (4a).

6. The scroll compressor (10a) as set forth in claim 1, characterized by, A radial dimension of the first cavity (12) is smaller than a radial dimension of the second cavity (14).

7. The scroll compressor (10a) as set forth in claim 1, characterized by, A step portion (17a) is arranged between an inner wall of the thrust portion (15a) and an inner wall of the extension portion (16a), and the first bearing (2) is arranged at the step portion (17a).

8. The scroll compressor (10a) according to any one of claims 1 to 3, characterized in that, The first balance weight (4a) is arranged substantially centrally in an axial direction between the first bearing (2) and the second bearing (3).

9. The scroll compressor (10a) according to any one of claims 1 to 3, characterized in that, The scroll compressor (10a) further comprises a second balance weight (5) arranged on an opposite side of the motor (9) from the first balance weight (4a).

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