JPH074367A - Scroll compressor - Google Patents

Abstract

PURPOSE:To reduce load applied to thrust bearings by pressure difference between both end parts of a driving shaft so as to prevent the seizure of the thrust bearings and thereby to improve the durability of the thrust bearings. CONSTITUTION:Thrust bearings 26, 37 are interposed between a driving shaft 10 and a block 18 so as to seal the high pressure side and low pressure side, and an oil feeding through-hole 39 is formed in such a way that one end is opened to the high pressure side shut off by the thrust bearings 26, 37 and that the other end is opened to a space partitioned by the end part of an oscillating shaft 21 extended being decentered from the driving shaft to and by an insert hole with the oscillating shaft 21 inserted therein. An annular clearance formed by the oscillating shaft 21 and the insert hole is provided with specified throttle, so that high pressure lubricating oil is supplied to the end part of the oscillating shaft 21 through the oil feeding through-hole 39 to obtain the high pressure state. Pressure difference between both ends of the driving shaft 10 can be thereby eliminated, and load applied to the thrust bearings 26, 37 can be reduced.

Description

Detailed Description of the Invention

[0001] The present invention relates to a scroll type compressor for compressing sucked refrigerant by changing the volume of a compression chamber formed by a fixed scroll member and an orbiting scroll member.

[0002]

2. Description of the Related Art Conventionally, in a scroll type compressor, a compression chamber is defined by a fixed scroll member and an orbiting scroll member, and the orbiting scroll member swings with respect to the fixed scroll member. Lubrication and sealing on the sliding contact surface of are important problems.

To solve this problem, for example, Japanese Patent Laid-Open No. 3-14
The scroll compressor disclosed in Japanese Patent No. 9391 has a rotary positive displacement oil pump configured and arranged to reliably supply a sufficient flow rate to a bearing regardless of the flow rate of lubricating oil supplied to a compression work space. It is possible to do. As a result, a large amount of lubricating oil can be secured against a high load applied to the orbiting drive bearing, the eccentric bearing, and the first main bearing.

[0004]

However, in the above-mentioned reference, when the fixed scroll member and the orbiting scroll member are made of a material other than iron, such as aluminum, for reasons such as weight reduction and cost reduction of the compressor, Since the back pressure applied to the orbiting scroll member is high, the orbiting scroll member is pressed toward the fixed scroll member side, and the sliding contact portion between the orbiting scroll member and the fixed scroll member is seized. Occurs.

Further, the pressure of the high pressure chamber is applied to one side of the drive shaft, and the low pressure or the intermediate pressure is applied to the other side of the drive shaft. Therefore, the load of the drive shaft is always biased toward the orbiting scroll member. Therefore, the load of the drive shaft is provided by the thrust bearing. However, if this load is large, seizure of the thrust bearing will occur, and since this load is always applied,
There is a problem that the durability of the thrust bearing is shortened.

Therefore, according to the present invention, the load on the thrust bearing is reduced by eliminating the pressure difference between both ends of the drive shaft, seizure of the thrust bearing is prevented, and the durability of the thrust bearing is improved. It is to provide a scroll type compressor that can be improved.

[0007]

Therefore, the present invention is
An electric motor, which is arranged in a high-pressure space in the closed case and includes a stator fixed in the closed case and a rotor fixed to the drive shaft, and a swing shaft eccentrically extending to the drive shaft, An orbiting scroll member having an insertion hole into which the orbiting shaft is inserted, a fixed scroll member that meshes with the orbiting scroll member to form a compression chamber, and the fixed scroll member is fixed in a hermetically sealed case, A block for rotatably sandwiching the orbiting scroll member with the fixed scroll member, and a thrust bearing is interposed between the drive shaft and the block to seal the high pressure side and the low pressure side, and one end of the block is provided. The oil supply through-hole is formed so as to open on the high-pressure side blocked by the thrust bearing and open at the other end into a space defined by the end of the swing shaft and the insertion hole.

[0008]

Therefore, in the present invention, the thrust bearing is interposed between the drive shaft and the block to shut off the high pressure side and the low pressure side, and one end is opened to the high pressure side shut off by the thrust bearing, and the other is opened. By forming an oil supply through hole that opens into a space defined by the end of the swing shaft whose end is eccentrically extended to the drive shaft and the insertion hole into which the swing shaft is inserted, high-pressure lubricating oil is formed. Since the oil can be supplied to the end portion of the swing shaft via the oil supply through hole, the pressure difference between the upper end and the lower end of the drive shaft can be eliminated, and the above problem can be achieved.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

In the scroll compressor 1 shown in FIG. 1, a cylindrical member 3 provided with a refrigerant suction port 2, a lid member 4 closing the upper end of the cylindrical member 3, and a bottom member closing the lower end. The closed case 6 is constituted by 5 and. The lid member 4 includes a refrigerant discharge port 7 and an electric motor 8.
The power supply terminal 9 is provided.

The electric motor 8 is, for example, a DC brushless motor, a drive shaft 10, a rotor (rotor) 11 fixed to the drive shaft 10 and having permanent magnets arranged around the drive shaft 10, and an inner peripheral surface of the cylindrical member 3. And a stator (stator) 13 around which a coil 12 is wound.

The drive shaft 10 is rotatably held by a drive shaft holding member 14 via a bearing 15, an upper balance weight 16 is arranged near the upper end, and a rotor 11 is fixed below the upper balance weight 16. ing. A lower balance weight 17 is fixed below the rotor 11, and a lower portion of the balance weight 17 is inserted into a through hole 19 formed in a block 18 described below and is rotatably held by a main bearing 20. . Further, a swing shaft 21 is provided at the lower end of the drive shaft 10 so as to be eccentric with respect to the central axis of the drive shaft.

The block 18 is fixed to the inner peripheral surface of the cylindrical member 3 and has a through hole 19 formed through the center thereof. A fixed scroll member 22 described below is fixed to the lower end surface by a screw 27. As a result, an orbiting scroll member 23, which will be described below, is rotatably held. Further, in order to hold the drive shaft 10, the drive shaft 10 and the block 1
In addition to the main bearing 20, a thrust bearing (second thrust bearing) 37 is interposed between the eight. The lower portion of the through hole 19 is formed so that the projecting portion 23b in which the insertion hole 23a of the swing scroll member 23 is formed can swing.
It has a large diameter.

An Oldham ring housing groove 25 for housing an Oldham ring 24 for preventing rotation of the orbiting scroll member 23 is formed on the sliding surface of the block 18 with the orbiting scroll member 23. Further, the sliding surface is provided with a first lubricating oil groove having an appropriate throttle.
Thrust bearings 26 are provided.

The orbiting scroll member 23 has an upper end surface
It has a projecting portion 23b projecting in the center and an insertion hole 23a formed in the projecting portion 23b and into which the swing shaft 21 is inserted. A scroll 23c is formed.

The fixed scroll member 22 has a fixed scroll 22a that meshes with the orbiting scroll 23c to define a compression chamber 28, and the refrigerant suction port 2 and the compression chamber 28 are provided on one side. Inhalation chamber 2 interposed between the tip and
2b is formed, and a refrigerant outlet 22c that communicates with the final stage of the compression chamber 28 is formed in the center of the lower end surface. A cover 30 that defines the refrigerant discharge passage 29 is fixed to the lower end surface of the fixed scroll member 22. A bypass passage 31 that connects the compression chamber 28 and the refrigerant discharge passage 29 is formed near the middle stage of the compression chamber 28, and is opened when the pressure in the compression chamber 28 exceeds a predetermined value. It has become so.

The scroll type compressor 1 having the above construction
When the electric motor 8 is driven, the oscillating scroll member 23 eccentrically attached to the drive shaft 10 of the electric motor 8
Performs a swinging motion with respect to the fixed scroll member 22,
The compression chamber 28 defined by the orbiting scroll 23c and the fixed scroll 22a gradually decreases in volume from the suction side to the discharge side. As a result, the refrigerant sucked from the refrigerant suction port 2 is compressed and discharged from the refrigerant outlet 22c to the refrigerant discharge passage 29, and the fixed scroll member 2
2 and the coolant passage 3 continuously formed in the block 18.
2 and an extension pipe 33 attached to the block 18 and a space (high pressure chamber) 34 in which the electric motor 8 is arranged.
Then, the refrigerant is discharged from the refrigerant outlet 7 to the next stage of the cooling cycle.

In the high pressure chamber 34, the lubricating oil separated by the rotation of the electric motor 8 is stored in the oil sump 35 formed on the upper portion of the block 18. Since the pressure of the high pressure chamber 34 is applied to the lubricating oil accommodated in the oil sump 35, the differential pressure between the high pressure and the low pressure on the suction side of the compression chamber 28 causes a difference from the lubricating oil suction port 36 shown in FIG. It flows into the space 41 above the second thrust bearing 37.

The lubricating oil flowing into the space 41, while lubricating the main bearing 20, ascends the oil supply groove 38 formed on the outer peripheral surface of the drive shaft 10 to reach the upper end, and The second path is the path extending from the space 41 above the thrust bearing 37 to the space 40 defined by the end of the swing shaft 21 and the insertion hole 23a through the oil supply through hole 39. In the oil supply groove 3
It flows out from the upper end of 8 and returns to the oil sump 35 again.

In the latter route, the swing shaft 2
The pressure in the space 40 is maintained at a high pressure by the action of reducing the clearance formed by the outer peripheral surface of No. 1 and the inner peripheral surface of the insertion hole 23a. The lubricating oil passes through this clearance and passes through the outer peripheral surface of the swing shaft 21 and the insertion hole 23a.
While lubricating the sliding portion of the inner peripheral surface of the above, it reaches the space 42 below the second thrust bearing 37.

The space 42 is formed by the insertion hole 23 on the upstream side.
The intermediate pressure or the low pressure is adjusted by the throttling action due to the clearance between the a and the swing shaft 21 and the throttling action formed in the first thrust bearing 26 on the downstream side. By the pressure difference with the low pressure of
Through the thrust bearing 26 of the Oldham ring storage groove 25
It is possible to adjust the amount of lubricating oil. As a result, the lubricating oil reaching the Oldham ring housing groove 25 reaches the suction chamber 22b formed in the fixed scroll member 22 after lubricating the Oldham ring 24, and is sucked into the compression chamber 28 together with the sucked refrigerant. To seal and lubricate the compression chamber 28.

Therefore, since the space 40 is maintained at a high pressure by the throttling action of the clearance formed by the outer peripheral surface of the swing shaft 21 and the inner peripheral surface of the insertion hole 23a, the space 40 is maintained in the swing shaft 21. The high pressure is applied from the lower side to the upper side, whereby the downward load applied to the drive shaft 10 can be reduced, and thus the load on the second thrust bearing 37 can be reduced.

[0023]

As described above, according to the present invention, the thrust bearing is interposed between the drive shaft and the block to shut off the high pressure side and the low pressure side, and one end is shut off by the thrust bearing. An oil supply through hole is formed in the space defined by the end of the swing shaft that is open to the high pressure side and has the other end eccentrically extending to the drive shaft and the insertion hole into which this swing shaft is inserted. Further, since the annular clearance formed by the swing shaft and the insertion hole has a predetermined throttle, high-pressure lubricating oil can be supplied to the end of the swing shaft through the oil supply through hole. In addition, since the pressure difference between the upper end and the lower end of the drive shaft can be eliminated, the load applied to the thrust bearing can be reduced, seizure of the thrust bearing can be prevented, and the durability can be improved.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a scroll compressor according to an embodiment of the present invention.

FIG. 2 is a partially enlarged sectional view of a scroll compressor according to an embodiment of the present invention.

[Explanation of reference numerals] 1 scroll type compressor 6 hermetically sealed case 8 electric motor 10 drive shaft 11 rotor 13 stator 18 block 20 main bearing 21 swing shaft 22 fixed scroll member 23 swing scroll member 23a insertion hole 26 first thrust bearing 28 compression chamber 34 high pressure chamber 35 oil sump 36 lubricating oil introduction hole 37 second thrust bearing 39 oil supply through hole

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location F04C 29/02 361 A 6907-3H

Claims (1)

[Claims] 1. An electric motor, which is arranged in a high-pressure space in a closed case and is constituted by a stator fixed in the closed case and a rotor fixed to a drive shaft, and eccentrically extended to the drive shaft. An oscillating shaft, an oscillating scroll member having an insertion hole into which the oscillating shaft is inserted, a fixed scroll member that meshes with the oscillating scroll member to form a compression chamber, and the fixed scroll member in a closed case. And a block for rotatably sandwiching the orbiting scroll member with the fixed scroll member, and a thrust bearing is interposed between the drive shaft and the block to seal the high pressure side and the low pressure side. An oil supply through hole is formed, one end of which opens on the high-pressure side blocked by the thrust bearing, and the other end of which opens into a space defined by the end of the swing shaft and the insertion hole. Scroll type compressor characterized by