US20110150690A1

US20110150690A1 - Oil supply structure for refrigerant compressor

Info

Publication number: US20110150690A1
Application number: US12/763,822
Authority: US
Inventors: Yueh-Ju Tang; Shu-Er Huang; Yu-Choung Chang
Original assignee: Industrial Technology Research Institute ITRI
Current assignee: Industrial Technology Research Institute ITRI
Priority date: 2009-12-17
Filing date: 2010-04-20
Publication date: 2011-06-23
Also published as: TW201122305A; TWI384157B

Abstract

An oil supply structure for a refrigerant compressor is connected to a main shaft of the refrigerant compressor. The oil supply structure has a concave recessed from a periphery to a center, an oil hole penetrating the center of the concave and in communication with an oil supply passage of the main shaft, and at least one blade protruding from the concave and extending from the periphery towards the oil-hole. A rotation direction of the blade is opposite to a rotation direction of the main shaft. Through a simple structure in a form of an impeller, the oil supply structure can generate the function of a centrifugal pump by the concave and the blade during rotation, so as to change the supply of a lubricating oil according to changes in the rotation rate.

Description

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This application claims priority to and the benefit of Taiwan Patent Application No. 098143294, filed Dec. 17, 2009, the contents of which are incorporated herein in their entireties by reference.

BACKGROUND OF THE DISCLOSURE

1. Technical Field
The present disclosure relates to the field of a refrigerant compressor, and more particularly to an oil supply structure having a simple structure and capable of improving the reliability of lubricating oil supply.
2. Related Art
A revolving-driven refrigerant compressor achieves the effect of compressing a refrigerant gas by relative rotation of an orbiting pump element and a fixed pump element. However, when the orbiting element rotates, significant friction occurs at junctions between the orbiting element and a base body, a bearing, and a fixing member. Therefore, an oil supply pump is required to supply a lubricating oil to portions of the junctions between the moving elements at which the friction occurs for lubrication.
In the field of refrigerant compressors, a positive displacement oil pump such as a gear pump is generally used to supply a fixed amount of lubricating oil to lubricate the parts requiring lubrication. In the gear pump, an eccentricity and a difference in the numbers of inner and outer teeth are used as changes of the volume of the oil supply mechanism, and the gear pump has advantages of a positive displacement volume pump of high head and constant displacement. However, in the refrigerant compressor, a pressure inside the case is used as a back pressure of the gear pump, and since the pressure is variable, but the gear needs to work under a steady back pressure, a spring member is generally used as a pressure accumulator to dynamically compensate for the back pressure, in order to prevent the volume efficiency from decreasing due to leakage; or a friction plate is designed so as to reduce an axial variable load of the gear pump. In any case, the structure of the gear pump has disadvantages such as requiring a large number of elements and having a poor assembly efficiency.
The pump with the swing rotors also belongs to positive displacement volume pumps, and has similar advantages and disadvantages to the gear pump, except that the stator and the rotors are circular, which are easily manufactured. However, since a swing-driven crankshaft requires eccentric driving and friction loss occurs at the contact point, the type of the pump with the rocking rotors has disadvantages of noise and power loss.
Although the positive displacement volume pump can provide constant displacement, the positive displacement volume pump needs to be designed to be capable of accurately estimating the demand on the supply of the lubricating oil. Once the rotation rate or operation condition is significantly changed, the positive displacement volume pump cannot provide a response in real time to the corresponding demand on the supply of the lubricating oil.
For example, during operation at a high rotation rate, when the flow of the lubricating oil needs to be increased to lubricate the bearing and dissipate the heat, the positive displacement volume pump cannot rapidly increase the flow of the lubricating oil, which leads to a decrease in the temperature resistance of the bearing of the compressor, resulting in that the bearing may be damaged after operation at a high rotation rate for a long time. The problems are generally overcome by using an excessive oil supply design, but in this manner, when the large amount of the lubricating oil is not required during operation at a low rotation rate, problems such as excessive oil supply and power loss on the oil transmission of the main shaft will occur.

SUMMARY

Accordingly, the present disclosure is directed to an oil supply structure for a refrigerant compressor, which can reduce the number of components required and is capable of changing the supply of a lubricating oil according to the rotation rate of a main shaft.
In order to achieve the objectives, the oil supply structure of the present disclosure is connected to one end of a main shaft of a refrigerant compressor extending to an oil tank. The oil supply structure has a concave formed on one end opposite to the main shaft and recessed from a periphery to a center, an oil hole penetrating the oil supply structure from the center of the concave and in communication with an oil supply passage of the main shaft, and at least one blade protruding from the concave and extending from the periphery towards the oil hole. A rotation direction of the blade is opposite to a rotation direction of the main shaft.
In the oil supply structure of the present disclosure, the function of a centrifugal pump is generated by the inwardly recessed concave and the blade during rotation, such that the oil supply structure of the present disclosure generates different centrifugal forces according to changes in the rotation rate, so as to change the amount of the lubricating oil flowing into the oil hole and pressurize the lubricating oil, thereby improving the oil feeding efficiency for lubrication.
The oil supply structure of the present disclosure is only structure in a form of an impeller, which has a simple structure and a small number of mechanical elements, and thus can be easily manufactured and assembled.
In an embodiment, the oil supply structure is integrated with the main shaft to form a unity, and is directly molded on one end of the main shaft by integral molding.
In an embodiment, the oil supply structure is an impeller, the impeller has a main body, the main body is slightly in a horn shape and has a columnar end and an expanded end, the columnar end is used to be assembled to and combined with the oil supply passage of the main shaft, the concave is formed on the expanded end, the oil hole penetrates the main body, and each blade protrudes from the concave. In an implementation, the columnar end is used to be combined with the oil supply passage of the main shaft in a tight-fitting manner.
In an embodiment, the refrigerant compressor is transversely disposed, and an oil collector is sleeved on an outer edge of the oil supply structure. The oil collector has a main body having a hollow chamber, the main body has an oil suction pipe extending downwards therefrom, and the oil suction pipe extends into the lubricating oil of the oil tank, such that the oil supply structure can stably suck the lubricating oil.
In order to make the aforementioned features and characteristics of the present disclosure more comprehensible, embodiments accompanied with figures are described in detail below.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic cross-sectional structural view of the present disclosure applied to a revolving-driven compressor;

FIG. 2 is a schematic cross-sectional structural view of the present disclosure;

FIG. 3 is a three-dimensional outside view of the present disclosure;

FIG. 4 is a schematic cross-sectional structural view of a second embodiment of the present disclosure;

FIG. 5 is a three-dimensional outside view of the second embodiment of the present disclosure;

FIG. 6 is a schematic cross-sectional structural view of a third embodiment of the present disclosure; and

FIG. 7 is a schematic cross-sectional structural view of a fourth embodiment of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, for purpose of explanation, numerous specific details are set forth in order to provide a through understanding of the disclosed embodiments. It will be apparent, however, that one or more embodiments may be practiced without these specific details. In other instances, well-known structures and devices are schematically shown in order to simplify the drawing.
Embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.
FIG. 1 is a schematic cross-sectional structural view of the present disclosure applied to a revolving-driven compressor, FIG. 2 is a schematic cross-sectional structural view of the present disclosure, and FIG. 3 is a three-dimensional outside view of the present disclosure.
In this embodiment, the revolving-driven refrigerant compressor is described and shown by taking a scroll compressor as an example, but the present disclosure is not limited thereto. In the structure of the compressor 1, a motor stator 11 and a motor rotor 12 are disposed in a housing 10, and the motor rotor 12 is combined with a main shaft 13.
One end of the main shaft 13 has an eccentric shaft 14, the eccentric shaft 14 is connected to an orbiting scroll 15, the orbiting scroll 15 is rotatably disposed in the housing 10, and a fixed scroll 16 is disposed corresponding to the orbiting scroll 15. Therefore, when the motor rotor 12 and the main shaft 13 rotate, the eccentric shaft 14 drives the orbiting scroll 15 to perform an engaging movement of revolving rather than rotating relative to the fixed scroll 16, and perform compression operations such as suction, compression, and discharging on a refrigerant in the above movement manner.
In order to provide the lubricating oil required during the rotation of the orbiting scroll 15, an oil tank 17 is disposed on one side of the housing 10 away from the fixed scroll 16, and one end of the main shaft 13 opposite to the eccentric shaft 14 extends to the oil tank 17 and is connected to an oil supply structure 2.
Referring to FIG. 2 and FIG. 3, the oil supply structure 2 of the present disclosure is an impeller structure in a form of a centrifugal pump, the oil supply structure 2 has a concave 21 recessed from a periphery to a center on one end opposite to the main shaft 13, an oil hole 22 on the center of the concave 21, and at least one blade 23 protruding from a surface of the concave 21 and extending from the periphery of the concave 21 towards the oil hole 22. A rotation direction of the blade 23 is opposite to a rotation direction of the main shaft, and a surface of the blade 23 is inclined towards the oil hole 22, such that the inclination of the surface of the blade 23 has a fluid guiding function.
In this embodiment, the oil supply structure 2 is directly fabricated on the end of the main shaft 13 opposite to the eccentric shaft 14 by electrical discharge machining or other methods, such that the oil supply structure 2 is integrated with the main shaft 13 to form a unity. The concave 21 is in a form of a concave camber. The oil hole 22 extends into the main shaft 13, and the main shaft 13 has an oil supply passage connected to the oil hole 22. The oil supply passage is formed by a first passage 131 and a second passage 141 (as shown in FIG. 1). The first passage 131 extends from a center of one end of the main shaft 13 connected to the oil supply structure 2 towards an other end of the main shaft 13, the second passage 141 extends from a center of the eccentric shaft 14 towards the first passage 131, and meets and communicates with the first passage 131 in the main shaft 13, such that the lubricating oil can be supplied from the oil hole 22 through the first passage 131 and the second passage 141 to the orbiting scroll 15 for lubrication. In this embodiment, the oil supply structure 2 has six blades 23, and the number and inclined angle of the blades 23 and the recessed depth of the concave 21 may be adjusted according to the amount of oil to be supplied.
In the oil supply structure 2 of the present disclosure, the function of a centrifugal pump is generated by the inwardly recessed concave and the blades, such that the oil supply structure 2 of the present disclosure generates different centrifugal forces according to changes in the rotation rate, so as to determine the amount of the lubricating oil flowing into the oil hole and pressurize the lubricating oil, and achieve an appropriate lubrication effect by oil injection under the guide of the first passage 131 and the second passage 141, thereby improving the oil feeding efficiency for lubrication. The oil supply structure 2 of the present disclosure is an impeller structure in a form of a centrifugal pump, which has a simple structure, can effectively reduce the number of mechanical elements, and thus can be easily manufactured and assembled.
Further, the oil supply structure 2 of the present disclosure has speed characteristic of the centrifugal pump, and is capable of adjusting the supply of the lubricating oil according to the rotation rate of the main shaft 13, so as to achieve the effect of providing a stable oil supply through flow variation, thereby avoiding a problem that due to an excessively slow response to the increase of the amount of the lubricating oil, a bearing of the orbiting scroll 15 is heated due to friction and the heat cannot be dissipated in time, resulting in that the bearing of the orbiting scroll 15 is damaged due to heat accumulation.
In addition, a thickness of a lubricating oil film is correlated to the friction loss of the compressor, and both excessive lubricating oil and insufficient lubricating oil affect the lifetime of the bearing and power consumption of the compressor. The present disclosure has the effect of providing a stable oil supply through flow variation, and is capable of adjusting the supply of the lubricating oil according to the rotation rate of the main shaft 13, so as to prevent an excessive or insufficient supply of the lubricating oil, thereby increasing the lifetime and reliability of the bearing of the compressor, and reducing the power loss of the main shaft 13.
FIG. 4 is a schematic cross-sectional structural view of a second embodiment of the present disclosure, and FIG. 5 is a three-dimensional outside view of the second embodiment of the present disclosure. The oil supply structure is a separate impeller 4. The impeller 4 has a separate main body 40. The main body 40 is slightly in a horn shape and has a columnar end 401 and an expanded end 402. The columnar end 401 is used to be combined with the a first passage 331 of a main shaft 33 in a tight-fitting manner, such that the main body 40 can rotate along with the main shaft 33. The concave 41 is formed on the expanded end 402, the oil hole 42 penetrates the main body 40, and a plurality of blades 43 is formed on the concave 41.
After the separate impeller 4 is combined with the main shaft 33, the same effect as the oil supply structure according to the first embodiment can also be achieved.
FIG. 6 is a schematic cross-sectional structural view of a third embodiment of the present disclosure. Referring to FIG. 6, the revolving-driven compressor 5 is transversely disposed. An oil supply structure 6 is integrally formed on one end of the main shaft 53 extending to the oil tank 57. An oil collector 7 is sleeved on an outer edge of the oil supply structure 6. The oil collector 7 has a main body 70 having a hollow chamber, the main body 70 has an oil suction pipe 71 extending downwards therefrom, and the oil suction pipe 71 extends into the lubricating oil of the oil tank 57, so as to ensure that the oil supply structure 6 can obtain the lubricating oil. Thus, this embodiment can also achieve the same effect as the first embodiment.
Definitely, in addition to the application to the revolving-driven compressor as described in the above embodiments, the oil supply structure for the refrigerant compressor of the present disclosure may also be applied to other types of refrigerant compressors. FIG. 7 is a schematic cross-sectional structural view of a fourth embodiment of the present disclosure. Referring to FIG. 7, in this embodiment, the oil supply structure for the refrigerant compressor of the present disclosure is implemented on a rotary compressor. The rotary compressor 8 includes a motor 81 for driving a main shaft 82. The main shaft 82 penetrates a compression mechanism 83 and includes an eccentric shaft 821 corresponding to the compression mechanism 83, so as to drive a rotor 84 to operate in the compression mechanism 83. The oil supply structure 9 of the present disclosure is disposed on one end of the main shaft 82 penetrating the compression mechanism 83. Thus, the same effect of improving the oil supply efficiency as the first embodiment can also be achieved.
In addition, the present disclosure may also be applied to a transversely disposed rotary compressor, and during implementation, the application can be realized by simply combining the oil collector in the third embodiment with the fourth embodiment.
The disclosure being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.

Claims

1. An oil supply structure for a refrigerant compressor, connected to one end of a main shaft of the refrigerant compressor extending to an oil tank, comprising:

a concave, formed on one end opposite to the main shaft, and recessed from a periphery to a center;

an oil hole, penetrating the oil supply structure from the center of the concave, and in communication with an oil supply passage of the main shaft; and

at least one blade, protruding from the concave, and extending from the periphery towards the oil hole, wherein a rotation direction of the blade is opposite to a rotation direction of the main shaft.

2. The oil supply structure for a refrigerant compressor according to claim 1, wherein the oil supply structure is integrated with the main shaft to form a unity and is directly molded on one end of the main shaft.

3. The oil supply structure for a refrigerant compressor according to claim 2, wherein the oil supply structure is directly molded on one end of the main shaft.

4. The oil supply structure for a refrigerant compressor according to claim 1, wherein the oil supply structure is an impeller, the impeller has a main body, the main body is slightly in a horn shape and has a columnar end and an expanded end, the columnar end is used to be combined with the oil supply passage of the main shaft, the concave is formed on the expanded end, the oil hole penetrates the main body, and the blade protrudes from the concave.

5. The oil supply structure for a refrigerant compressor according to claim 4, wherein the columnar end and the oil supply passage of the main shaft are configured to be assembled together, so as to enable the impeller to be directly combined with the oil supply passage of the main shaft.

6. The oil supply structure for a refrigerant compressor according to claim 1, wherein the refrigerant compressor is transversely disposed, and an oil collector is sleeved on an outer edge of the oil supply structure, so as to suck the lubricating oil.

7. The oil supply structure for a refrigerant compressor according to claim 6, wherein the oil collector has a main body having a hollow chamber, the main body has an oil suction pipe extending downwards therefrom, and the oil suction pipe extends into the lubricating oil of the oil tank of the refrigerant compressor.