CN220505305U - Scroll compressor with oil blocking structure - Google Patents

Abstract

The utility model provides a scroll compressor, which comprises a compression mechanism and a driving mechanism, wherein the compression mechanism comprises an movable scroll, the driving mechanism comprises a driving shaft, an eccentric pin which is engaged with the movable scroll to drive the movable scroll is arranged at the shaft end of the driving shaft, an unloading bush and a driving bearing are arranged between the eccentric pin and the movable scroll, the unloading bush is positioned at the radial outer side of the eccentric pin, rotates together with the eccentric pin and can radially move relative to the eccentric pin, the driving bearing is positioned at the radial outer side of the unloading bush, an oil way flowing through a radial gap between the eccentric pin and the unloading bush is taken as a first oil way, an oil way flowing through a radial gap between the unloading bush and the driving bearing is taken as a second oil way, and the scroll compressor further comprises an oil blocking structure which is arranged in the first oil way and is used for increasing the flowing resistance of lubricating oil in the first oil way.

Description

Scroll compressor with oil blocking structure

Technical Field

The present utility model relates to a scroll compressor having a structure capable of improving lubrication of a drive bearing.

Background

This section provides background information related to the present disclosure, which does not necessarily constitute prior art to the present utility model.

Referring to fig. 10, the scroll compressor 1 generally has a compression mechanism CM including a fixed scroll 50 and an movable scroll 10, a drive shaft 20 connected to a motor 60 of a drive mechanism DM, and the like. The driving shaft 20 is provided at its shaft end near the orbiting scroll 10 with an eccentric pin 21, and the eccentric pin 21 is configured to be inserted inside the hub 11 of the orbiting scroll 10 and to be in driving engagement with the orbiting scroll 10 through an unloading bushing 30 provided radially outside the eccentric pin 21 and a driving bearing 40 provided radially outside the unloading bushing 30, thereby making the orbiting scroll 10 orbit with respect to the fixed scroll 50. During operation of the scroll compressor 1, there is relative movement between the unloader bushing 30 and the drive bearing 40, resulting in wear of the drive bearing 40.

For this purpose, an oil supply passage 22 penetrating the drive shaft is provided in the drive shaft 20 so that lubricating oil can flow from the bottom oil sump 55 through the passage to between the unloading bushing 30 and the eccentric pin 21 and between the unloading bushing 30 and the drive bearing 40 through the oil hole at the top of the eccentric pin 21 to lubricate the unloading bushing 30 and the drive bearing 40.

Nevertheless, since the gap between the unloading bushing 30 and the drive bearing 40 is small and the gap between the eccentric pin 21 and the unloading bushing 30 is much larger, a considerable amount of lubricating oil will flow into the gap between the eccentric pin 21 and the unloading bushing 30 and back into the bottom oil sump 55, resulting in a small amount of oil flowing into between the unloading bushing 30 and the drive bearing 40 that effectively lubricates the drive bearing 40, resulting in severe wear and even premature failure of the drive bearing 40.

There may be several means to improve the wear of the drive bearing: for example, changing the drive bearing to have a larger size, however, in the event that the design of the scroll compression mechanism has been set, the size of the drive bearing will not be changed; or the material of the drive bearing may be changed and less abrasive materials are used to make the drive bearing, however, for new materials, it is often necessary to perform longer-term experiments to verify the suitability of the material and the possible risks, etc.

Accordingly, there is a need for a scroll compressor that can achieve the technical effect of significantly improving drive bearing wear by minimal modification to existing designs.

Disclosure of Invention

The object of the present utility model is to provide a scroll compressor which is capable of significantly improving the wear of the drive bearing by simple structural adjustment and/or by adding simple structural features.

The general idea of the present utility model is to increase the flow resistance of the lubricating oil through the oil passage between the unloading bushing and the eccentric pin, at the inlet or at the outlet in the scroll compressor by adding simple structural features and/or simply adapting the existing structure, thereby reducing the lubricating oil flowing into the oil passage to a certain extent, thereby increasing the amount of lubricating oil flowing into the oil passage between the unloading bushing and the drive bearing, thereby improving the lubrication condition of the drive bearing and thus reducing or preventing wear on the drive bearing.

The utility model provides a scroll compressor, which comprises a compression mechanism and a driving mechanism, wherein the compression mechanism comprises an movable scroll, the driving mechanism comprises a driving shaft, an eccentric pin which is engaged with the movable scroll to drive the movable scroll is arranged at the shaft end of the driving shaft, an unloading bush and a driving bearing are arranged between the eccentric pin and the movable scroll, the unloading bush is positioned at the radial outer side of the eccentric pin, rotates together with the eccentric pin and can radially move relative to the eccentric pin, the driving bearing is positioned at the radial outer side of the unloading bush, an oil way flowing through a radial gap between the eccentric pin and the unloading bush is taken as a first oil way, and an oil way flowing through a radial gap between the unloading bush and the driving bearing is taken as a second oil way, and the scroll compressor is characterized by further comprising an oil blocking structure which is arranged at the first oil way and is configured to increase the flowing resistance of lubricating oil in the first oil way.

Preferably, the second oil passage includes an oil groove provided on an outer peripheral surface of the unloader bush, the oil groove extending in an axial direction from a top end surface of the unloader bush.

Preferably, the oil sump terminates in a step near the bottom of the unloader bushing.

Preferably, the second oil passage further includes a recess provided on the top end surface of the unloading bush, which is connected to the oil groove.

Preferably, the oil blocking structure includes a radially extending protrusion for reducing the flow area of the first oil passage.

Preferably, the oil barrier is in the form of a radially extending annular gasket.

Preferably, the gasket is disposed against an end face of the unloader bush to reduce a flow area at an end portion of the first oil passage.

Preferably, the spacer is disposed against a bottom end face of the unloader bushing.

Preferably, the first oil passage further includes one or more notches provided on the bottom end surface of the unloading bushing.

Preferably, the ratio of the total flow area of both the oil groove and the slot is between 1.2 and 3.

Preferably, the unloader bush is provided at one end with a recess recessed radially outwardly along an inner peripheral surface thereof, the spacer being mounted in the recess.

Preferably, the radial protrusion is provided on an inner circumferential surface of the unloading bushing and/or an outer circumferential surface of the eccentric pin.

The scroll compressor according to the embodiment of the utility model has at least the following advantageous technical effects: the lubrication of the driving bearing can be obviously improved only by simple structural adjustment and/or simple structural features, and the driving bearing has low implementation cost and small implementation difficulty.

Drawings

The features and advantages of the present utility model will be more readily understood from the detailed description provided below, taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a longitudinal cross-sectional view of a portion of a scroll compressor according to an embodiment of the present utility model;

FIG. 2 is an enlarged partial longitudinal cross-sectional view of the scroll compressor illustrated in FIG. 1;

fig. 3a, 3b, 3c are perspective, top and bottom views of an unloading bushing of a scroll compressor according to an embodiment of the present utility model;

FIG. 4 is a perspective view of a portion of a scroll compressor according to an embodiment of the present utility model;

FIG. 5 is a perspective view of a oil blocking structure and an unloading bushing of a scroll compressor according to an embodiment of the present utility model;

FIGS. 6a, 6b, 6c are perspective, top and cross-sectional views of an oil blocking structure of a scroll compressor according to an embodiment of the present utility model;

FIG. 7 is a longitudinal cross-sectional view of a portion of a scroll compressor according to yet another embodiment of the present utility model;

FIG. 8 is a longitudinal cross-sectional view of an unloader bushing of the scroll compressor of FIG. 7;

FIG. 9 is a top view of a oil blocking structure of a scroll compressor according to yet another embodiment of the present utility model; and

fig. 10 is a longitudinal sectional view of a conventional scroll compressor.

Detailed Description

The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the utility model, its application, or uses. The same reference numerals are used to denote the same parts throughout the various drawings, and thus the construction of the same parts will not be repeated.

As shown in fig. 1, which shows a longitudinal sectional view of a portion of a scroll compressor according to an exemplary embodiment of the present utility model. The scroll compressor includes a compression mechanism and a driving mechanism for driving the compression mechanism. The compression mechanism includes an orbiting scroll 10 and a non-orbiting scroll (not shown). The drive mechanism includes a motor (not shown) and a drive shaft 20. The drive shaft 20 is provided at its shaft end adjacent the orbiting scroll 10 with an eccentric pin 21, the eccentric pin 21 projecting axially from a shoulder 24 of the drive shaft and being eccentric to the central axis of the drive shaft 20. The eccentric pin 21 can be inserted inside the hub 11 of the orbiting scroll 10 and configured such that the driving shaft 20 can drive the orbiting scroll 10 to orbit with respect to the fixed scroll by driving engagement of the eccentric pin 21 with the hub 11. Between the orbiting scroll 10 and the eccentric pin 21, there are provided an unloading bushing 30 and a driving bearing 40, the unloading bushing 30 being provided radially outside the eccentric pin 21, being rotatable together with the eccentric pin 21 and being radially movable with respect to the eccentric pin 21 to provide radial flexibility to the compression mechanism, so that there is a certain radial clearance between the unloading bushing 30 and the eccentric pin 21 and also a certain degree of wear. The drive bearing 40 is arranged radially outside the unloader bush 30. The drive bearing 40 may have a cylindrical shape and is fitted with the hub 11. When the scroll compressor is in an operating state, the unloading bushing 30 will rotate together with the eccentric pin 21, and the driving bearing 40 will orbit together with the orbiting scroll 10 with respect to the fixed scroll, so that there is a relative movement between the unloading bushing 30 and the driving bearing 40, resulting in wear between the outer surface of the unloading bushing 30 and the inner surface of the driving bearing 40, which are in contact with each other. For this purpose, an oil supply passage 22 penetrating the drive shaft 20 is provided in the drive shaft 20 so that lubricating oil can flow out from the oil pool through the oil supply passage 22 through the lubricating oil hole 23 at the top of the eccentric pin 21 and between the eccentric pin 21 and the unloading bush 30 and between the unloading bush 30 and the drive bearing 40 to lubricate the contact surfaces of the two, respectively, and at the same time, to cool the unloading bush 30 and the drive bearing 40, etc.

Specifically, as shown in fig. 2, which shows a partially enlarged longitudinal sectional view of the scroll compressor shown in fig. 1, the lubricating oil flowing out of the lubricating oil hole 23 at the top of the eccentric pin 21 will travel along two paths, wherein a portion of the lubricating oil flows into the gap between the eccentric pin 21 and the unloading bushing 30 as described above, and this portion flows directly back to the bottom oil pool and does not participate in the lubrication of the contact surface between the unloading bushing 30 and the drive bearing 40; another portion of the lubricating oil flows into the gap between the unloader bush 30 and the drive bearing 40, which portion of the lubricating oil actually participates in lubrication of the contact surfaces of the unloader bush 30 and the drive bearing 40. The gap between the eccentric pin 21 and the unloading bushing 30 is referred to herein as a first oil passage 100, and the gap between the unloading bushing 30 and the drive bearing 40 is referred to as a second oil passage 200, as shown, the radial dimension of the first oil passage 100 is significantly larger than the radial dimension of the second oil passage 200, and therefore the flow resistance of the lubricating oil in the first oil passage 100 is significantly smaller, and a larger amount of lubricating oil will flow into the first oil passage 100 and directly back to the bottom oil pool, resulting in that only a smaller amount of lubricating oil can participate in the lubrication of the drive bearing 40, that is, a smaller amount of lubricating oil is effective for lubricating the drive bearing 40.

To improve lubrication of the drive bearing 40, simple structural adjustments or simple structural features may be added to the unloader bushing 30 to increase the amount of lubrication oil that enters the second oil passage 200.

Fig. 3a, 3b, 3c show perspective, top and bottom views, respectively, of an unloading bushing 30 of a scroll compressor according to an embodiment of the present utility model. As shown, the unloading bush 30 has a hollow cylindrical shape, which can be accommodated in the inner cavity of the hub 11 and can be disposed between the eccentric pin 21 and the inner circumferential wall of the hub 11 in such a manner as to surround the eccentric pin 21, and the inner hollow cavity of the unloading bush 30 may have a shape matching the shape of the eccentric pin 21 so as to be rotatable together with the eccentric pin 21.

In some embodiments, an oil groove 32 having a certain width in the circumferential direction is provided on the outer circumferential surface 31 of the unloading bushing 30. The oil groove 32 may extend in an axial direction from the top end face of the unloader bushing 30, e.g., from the top end face to the bottom end face of the unloader bushing 30, or more preferably, the oil groove 32 may extend from the top end face of the unloader bushing 30 to a location a distance from the bottom end face such that the oil groove 32 terminates in a step 33 near the bottom of the unloader bushing, as shown.

By providing the oil groove 32 on the outer peripheral surface 31 of the unloading bushing 30, the flow area of the second oil passage 200 is increased, thereby allowing a larger amount of lubricating oil to flow into the second oil passage 200 from the lubricating oil hole 23 at the top of the eccentric pin 21; at the same time, by providing the stepped portion 33, it is also possible to store a certain amount of lubricating oil in the outer peripheral surface 31 of the unloading bush 30, i.e., the contact surface of the unloading bush 30 and the drive bearing 40, and thus a certain oil storage level is formed, so that it is possible to provide better lubrication of the drive bearing 40 and better cooling of the components such as the drive bearing 40 and the unloading bush 30.

More preferably, a recess 34 may be provided on the top end surface of the unloading bushing 30 at a position where it meets the oil groove 32 to facilitate guiding the lubricating oil flowing out of the lubricating oil hole 23 at the top of the eccentric pin 21 into the oil groove 32. In the drawings of the present application, the recess 34 is shown as a V-groove and has a width corresponding to the width of the oil groove 32. However, it will be appreciated that other shapes or other sizes of recesses are possible.

By providing the recess 34 on the top end surface of the unloading bush 30, it is advantageous to guide a larger amount of lubricating oil into the oil groove 32, and thus it is possible to increase the amount of lubricating oil in the second oil passage 200 and the amount of lubricating oil stored in the contact surface of the unloading bush 30 with the drive bearing 40.

In some embodiments, in order to improve lubrication of the drive bearing 40, the scroll compressor according to the present utility model is provided with an oil blocking structure 300, which oil blocking structure 300 is configured to increase the flow resistance of the lubricating oil in the first oil passage 100, so that the amount of lubricating oil passing through the first oil passage 100 can be reduced to some extent, and thus the amount of lubricating oil entering the second oil passage 200 can be increased to increase the effective amount of lubricating oil participating in lubrication of the drive bearing 40. The oil blocking structure 300 according to the embodiment of the utility model may be disposed in the first oil passage 100.

Fig. 4 shows a perspective view of a portion of the scroll compressor shown in fig. 1. In the following drawings, for clarity of illustration of the components, it is possible to further omit the orbiting scroll in the scroll compressor, the drive bearing, etc., and it will be understood by those skilled in the art that the second oil passage 200 is disposed outside the unloading bushing 30.

As shown in fig. 1, 2 and 4, the oil blocking structure 300 according to the embodiment of the present utility model is disposed under the unloading bushing 30, in particular, between the bottom end surface of the unloading bushing 30 and the shoulder 24 of the driving shaft 20, and is abutted against the bottom end surface of the unloading bushing, in other words, the oil blocking structure 300 is disposed at the lower end portion of the first oil passage 100, as shown in fig. 5, which shows the positional relationship of both the oil blocking structure 300 and the unloading bushing 30 of the scroll compressor as shown in fig. 1, 2 and 4. In this embodiment, the oil blocking structure 300 reduces the flow area of at least a portion at the outlet (lower end portion) of the first oil passage 100. Alternatively, the oil blocking structure 300 may also be provided above the unloading bushing 30 and against the top end surface of the unloading bushing 30, reducing the flow area of at least a portion at the inlet (upper end) of the first oil passage 100, i.e., the oil blocking structure 300 may be arranged at the upper end of the first oil passage 100.

In this example embodiment, the oil blocking structure 300 is in the form of an annular gasket 301, that is, the oil blocking structure 300 has a circular inner circumference and a circular outer circumference that are concentrically arranged, whereby the flow area of the first oil passage can be reduced in the entire circumferential direction and has a thinner thickness. Fig. 6a, 6b, 6c show a perspective view, a top view and a cross-sectional view, respectively, of the annular gasket 301. The annular washer 301 can pass through the eccentric pin 21 and be arranged substantially coaxially with the unloading bushing 30. The inner Zhou Zhishao of the annular gasket 301 is smaller than the inner periphery of the unloader bush 30 at a partial position in the circumferential direction, so that the radial clearance at the end portion of the first oil passage 100 is reduced at least partially, and the flow resistance of the lubricating oil in the first oil passage 100 is increased, so that the amount of the lubricating oil flowing into the first oil passage 100 is reduced to some extent, and the lubricating oil has to flow into the second oil passage 200.

It should be noted that the inner Zhou Zhishao of the annular gasket 301 may be larger than the outer periphery of the eccentric pin 21 at a partial position in the circumferential direction so as not to completely block the first oil passage 100 to ensure that the lubricating oil is not blocked.

As shown in fig. 1 and 2, the bottom end surface of the hub portion 11 of the orbiting scroll 10 of the scroll compressor is disposed at a certain axial distance from the shoulder portion 24 of the drive shaft 20, and therefore, even if the outer circumference of the annular gasket 301 exceeds the outer circumferential surface 31 of the unloading bushing 30 in the radial direction, it does not form any obstruction to the second oil passage 200. For example, the outer circumference of the oil blocking structure 300 may also be non-circular, as long as it is suitable for installation into a scroll compressor.

Fig. 7 shows a longitudinal sectional view of a portion of a scroll compressor according to yet another embodiment of the present utility model, the oil blocking structure of which is disposed inside the unloading bushing 30. Fig. 8 shows a longitudinal section of the unloading bushing of this embodiment. As shown in fig. 8, a circular recess 35 may be provided along the inner circumferential surface at the top of the unloader bushing 30, the recess 35 being recessed radially outwardly from the inner circumferential surface of the unloader bushing 30 and having an axial depth that is less than half the axial length of the unloader bushing 30. An oil blocking structure is mounted in the recess 35. Alternatively, a similar recess may be provided in the bottom of the unloader bush 30, and the oil blocking structure may be installed in the recess.

Fig. 9 shows a top view of the oil blocking structure of this embodiment. The oil blocking structure of this embodiment is in the form of a gasket 302, the outer periphery of which is circular and slightly smaller than the radial dimension of the recess 35 to facilitate installation in the recess 35. The inner periphery of the oil blocking structure 302 has a shape matching the shape of the eccentric pin 21, but should be larger than the outer periphery of the eccentric pin 21 at least at a part of the position in the circumferential direction, similarly to the foregoing embodiment, so as not to completely block the first oil passage 100.

Although the provision of the oil blocking structure in the form of a gasket at the upper or lower end portion of the first oil passage 100 or at the top or bottom of the unloading bushing 30, respectively, has been described above to increase the flow resistance of the lubricating oil in the first oil passage 100, it will be appreciated that the oil blocking structure 300 may take other forms, in particular may take other forms of protrusions, in particular may take other forms of radially extending protrusions. The oil blocking structure 300 may also be provided at any position in the first oil passage 100 other than the upper end portion and the lower end portion. For example, one protrusion (particularly, radial protrusions) or a plurality of protrusions spaced apart/staggered may be provided on the inner circumferential surface of the unloading bushing 30 or on the outer circumferential surface of the eccentric pin 21 to reduce the radial clearance of the first oil passage 100 at least at a partial position in the circumferential direction, thereby increasing the flow resistance of the lubricating oil in the first oil passage 100. For example, the above-described gasket may also be provided in the passage of the first oil passage (i.e., the radial gap between the eccentric pin and the unloading bushing), in which case the gasket may be regarded as a radially extending projection. Preferably, the protruding portion may extend from the inner circumferential surface of the unloading bushing 30 to a position spaced apart from the outer circumferential surface of the eccentric pin 21 or from the outer circumferential surface of the eccentric pin 21 to a position spaced apart from the inner circumferential surface of the unloading bushing 30 so as not to completely block the first oil passage 100. Alternatively, the radial dimension of the entire outer circumference of the eccentric pin 21 may be increased or the radial dimension of the entire inner circumference of the unloader bush 30 may be decreased in an appropriate manner to decrease the radial gap therebetween over the entire first oil passage 100.

In some embodiments, the amount of lubrication oil flowing into the second oil passage 200 may also be increased by reducing the flow resistance of lubrication oil in the second oil passage 200 in an appropriate manner. For example, the size of the oil groove 32 on the unloading bush 30 may be increased, for example, the width (the dimension in the circumferential direction) and/or the depth (the dimension in the radial direction) of the oil groove 32 may be increased, which may increase the flow area of the second oil passage 200 on the one hand, reduce the flow resistance of the lubricating oil in the second oil passage 200, and may also cause more lubricating oil to be stored in the oil groove 32 on the other hand, so that the effective amount of lubricating oil for the drive bearing 40 is increased, thereby providing better lubrication for the drive bearing 40 and better cooling for the components of the drive bearing 40 and the unloading bush 30, etc.

Additionally, in case the annular gasket 301 as a oil blocking structure abuts against the bottom end surface of the unloading bushing, in order to reduce the resistance when lubricating oil flows back to the bottom oil sump for facilitating the recovery of lubricating oil, one or more notches 36 may be provided in the bottom end surface of the unloading bushing 30, as shown in fig. 3a, 3b, 3c and fig. 5, two notches 36 being provided, which notches 36 are circumferentially spaced apart from the oil groove 32 and are located substantially symmetrically on both sides of the oil groove 32, which may avoid an excessive amount of lubricating oil flowing into the oil groove 32 via the notches 34. It will be appreciated that other numbers of notches may be provided or notches may be provided at other locations than those shown.

Furthermore, by providing the notches 36 and adjusting the ratio of the flow areas of the oil grooves 32 to the notches 36, an optimal balance of the amounts of lubrication oil flowing through the second oil passage 200 and the first oil passage 100 can be achieved, i.e. it can be ensured that an appropriate amount of lubrication oil is stored between the unloading bushing 30 and the drive bearing 40, preferably the ratio of the flow areas of the oil grooves 32 to the notches 36 is between 1.2-3. If the number of slots 36 and/or oil grooves 32 is more than one, the ratio of the total flow area of both oil grooves 32 and slots 36 may be between 1.2-3.

Alternatively, it is also possible to achieve the optimal balance of the amounts of lubricating oil flowing through the first oil passage 100 and the second oil passage 200 by adjusting the flow area ratio of the first oil passage 100 and the second oil passage 200.

Those skilled in the art will appreciate that the various added structural features described above, such as the oil groove 32, the step 33, the recess 34, the recess 35, the notch 36, etc. on the unloader bushing 30 may be accomplished by simple machining, and further, structural features such as radial protrusions may be accomplished mechanically or by adhesion, etc.

The scroll compressor according to the present utility model can significantly improve lubrication of the drive bearing by simple structural adjustment and/or addition of simple structural features, for example by simple addition of shims, simple machining, etc., thereby improving wear of the drive bearing with less machining difficulty, which can avoid the enormous effort and cost of redesigning the drive bearing, even the scroll compressor, with significant cost effectiveness. It should also be appreciated that the various features of the specific examples described above with reference to the drawings may be altered, interchanged, added, or deleted without departing from the spirit of the utility model.

Meanwhile, the scroll compressor according to the present utility model can ensure that a certain amount of lubricating oil is stored between the unloading bushing and the driving bearing, so that a good lubricating effect on the contact surface between the unloading bushing and the driving bearing can be ensured over a long period of time, thus prolonging the service lives of the unloading bushing and the driving bearing to further reduce costs.

The particular examples shown are for purposes of illustration only and are not intended to be limiting, as the specific examples described above are susceptible to variations. While some embodiments and variations of the present utility model have been specifically described, it will be understood by those skilled in the art that the present utility model is not limited to the embodiments and variations described above and shown in the drawings, but may include other various possible combinations and combinations. Other modifications and variations can be effected by those skilled in the art without departing from the spirit and scope of the utility model. All such modifications and variations are intended to be within the scope of the present utility model. Moreover, all the components described herein may be replaced by other technically equivalent elements.

Reference numerals:

scroll compressor 1

Orbiting scroll 10

Hub 11 of orbiting scroll 10

Drive shaft 20

Eccentric pin 21

Oil supply passage 22

Lubricating oil hole 23

Shoulder 24

Unloading bushing 30

Outer peripheral surface 31 of unloading bush 30

Oil groove 32

Step 33

Recess 34

Recess 35

Notch 36

Drive bearing 40

First oil passage 100

Second oil passage 200

Oil-blocking structure 300

Annular gasket 301

Gasket 302

Claims (12)

1. A scroll compressor comprising a compression mechanism including an orbiting scroll and a drive mechanism including a drive shaft provided at an axial end with an eccentric pin engaged with the orbiting scroll to drive the orbiting scroll, an unloading bushing located radially outward of the eccentric pin, rotatable with the eccentric pin and radially movable with respect to the eccentric pin, and a drive bearing located radially outward of the unloading bushing with an oil passage flowing through a radial gap between the eccentric pin and the unloading bushing being a first oil passage and an oil passage flowing through a radial gap between the unloading bushing and the drive bearing being a second oil passage, characterized in that the scroll compressor further includes an oil blocking structure provided to the first oil passage, the oil blocking structure being configured to increase a flow resistance of lubricating oil in the first oil passage.

2. The scroll compressor of claim 1, wherein the second oil passage includes an oil groove provided on an outer peripheral surface of the unloader bushing, the oil groove extending in an axial direction from a top end surface of the unloader bushing.

3. The scroll compressor of claim 2, wherein the oil sump terminates in a step near the bottom of the unloader bushing.

4. The scroll compressor of claim 2, wherein the second oil passage further includes a recess provided on the top end surface of the unloader bushing that interfaces with the oil sump.

5. The scroll compressor of any one of claims 2 to 4, wherein,

the oil blocking structure includes a radially extending protrusion for reducing a flow area of the first oil passage.

6. The scroll compressor of claim 5, wherein the oil blocking structure is in the form of a radially extending annular gasket.

7. The scroll compressor of claim 6, wherein the gasket is disposed against an end face of the unloader bushing to reduce a flow area at an end of the first oil passage.

8. The scroll compressor of claim 7, wherein the gasket is disposed against a bottom end surface of the unloader bushing.

9. The scroll compressor of claim 8, wherein the first oil passage further comprises one or more notches provided on the bottom end surface of the unloader bushing.

10. The scroll compressor of claim 9, wherein a ratio of a total flow area of both the oil sump and the slot is between 1.2-3.

11. The scroll compressor of claim 6, wherein the unloader bushing is provided at one end with a recess recessed radially outwardly along an inner peripheral surface thereof, the gasket being mounted in the recess.

12. The scroll compressor of claim 5, wherein the protrusion is provided on an inner circumferential surface of the unloading bushing and/or an outer circumferential surface of the eccentric pin.