JPH074369A - Scroll compressor - Google Patents

Abstract

PURPOSE:To prevent the seizure of thrust bearings and improve the durability of the thrust bearings by reducing load applied to the thrust bearings. CONSTITUTION:In annular thrust bearings 26, 37 disposed between a driving shaft 10 and a block 18 so as to receive a thrust load applied to the driving shaft 10, an annular oil groove 37a is formed annularly on the contact sliding face with the driving shaft 10, and a groove is formed to communicate this annular oil groove 37a with the outer peripheral side face so as to supply high pressure lubricating oil to the annular oil groove 37a from a lubricating oil lead-in hole through this communicating groove. The energizing force for energizing the driving shaft 10 upward can be thereby increased, and the thrust load can be reduced by this energizing force part.

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.

For this reason, the present invention provides a scroll type compressor capable of preventing the seizure of the thrust bearing and improving the durability of the thrust bearing by reducing the load applied to the thrust bearing. It is in.

[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 an oscillating scroll member eccentrically attached to the drive shaft, A fixed scroll member that meshes with the orbiting scroll member to form a compression chamber; and a block that fixes the fixed scroll member in a hermetically sealed case and that sandwiches the orbiting scroll member with the fixed scroll member so as to freely rotate. An annular thrust bearing which is arranged between the drive shaft and the block and receives a thrust load applied to the drive shaft, and an oil reservoir which is formed in the block and near the thrust bearing and which is formed below the high pressure chamber. In a scroll compressor having a lubricating oil introduction hole, an annular oil groove is formed on the thrust bearing in a sliding contact surface with the drive shaft. And forming, the annular oil groove and the outer peripheral side surface to form a groove for communicating the is to supply the high-pressure lubricating oil from the lubricating oil introducing hole in the annular oil groove through the groove.

[0008]

Therefore, according to the present invention, there is provided an annular thrust bearing which is arranged between the drive shaft and the block and receives a thrust load applied to the drive shaft. The drive shaft is formed by forming a groove and forming a groove that communicates the annular oil groove with the outer peripheral side surface, and supplying high-pressure lubricating oil from the lubricating oil introduction hole to the annular oil groove through the groove. Since the urging force for urging the engine can be increased and the thrust load can be reduced by this urging force, the above-mentioned 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 provided between the parts 8. The through hole 1
The lower part of 9 is the insertion hole 23 of the orbiting scroll member 23.
The diameter is formed to be large so that the protruding portion 23b where a is formed can swing.

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.
Leading to. In the high-pressure chamber 34, the lubricating oil is separated by the rotation of the electric motor 8 or the electric motor 8 is cooled, and then sent out from the refrigerant discharge port 7 to the next step. The separated lubricating oil is stored in the oil pool 35 formed on the upper portion of the block 18.

A high pressure from the high pressure chamber 34 is applied to the lubricating oil contained in the oil sump 35, and the lubricating oil is supplied to each part by the differential pressure between the high pressure and the low pressure on the suction side of the compression chamber 28. The lubricating oil contained in the oil sump 33 is sucked through the lubricating oil suction port 36 and flows near the upper portion of the second thrust bearing 37.

The second thrust bearing 37 has a structure shown in FIG.
As shown in (a), an annular oil groove 37a formed in an annular shape at a position apart from the inner circumference by a predetermined value, and the annular oil groove 37a and the outer circumference of the annular oil groove 37a radially outward from the annular oil groove 37a. A groove 37b that connects the side surfaces is formed. Also,
In another embodiment shown in FIG. 2 (b), the second thrust bearing 37 'has an annular oil groove 37a' formed in an annular shape at a position distant from the inner circumference by a predetermined value, and the annular oil groove 37a '.
A groove 37b 'is formed outwardly in the tangential direction to communicate with the annular oil groove 37a' and the outer peripheral side surface. Thereby, the grooves 37b, 3 of the second thrust bearings 37, 37 'are
High-pressure lubricating oil is supplied to 7b 'and the annular grooves 37a, 37a'.

While the main bearing 20 is being lubricated, the lubricating oil rises in the oil supply groove 38 formed on the outer peripheral surface of the drive shaft 10 to reach the upper end, and the oil from the thrust bearing 37. It is divided into a path that passes through the supply through hole 39 and reaches the bottom of the insertion hole 23a. From here, the lubricating oil rises along the sliding portion while lubricating the sliding portion between the insertion hole 23a and the swing shaft 21, and the protruding portion 23b.
The lubrication of the Oldham ring 24 is performed from the upper end to the outside through the bearing 26 to the Oldham ring housing groove 25.

After that, the lubricating oil is used as the fixed scroll member 2.
It reaches the suction chamber 22b formed in 2, and is sucked into the compression chamber 28 together with the sucked refrigerant to seal and lubricate the compression chamber 28.

In the scroll type compressor as described above, the high pressure chamber 34 in which the electric motor 8 is arranged has a high pressure,
Further, since the lower end portion of the drive shaft 10 has a low pressure or an intermediate pressure, a thrust load is applied to the drive shaft 10 downward.

In order to receive this thrust load, as shown in FIG. 3, a second thrust bearing 37 "(annular oil groove 37
a) and the radial groove 37b are not formed), but when all the thrust load applied to the drive shaft 10 is received by the second thrust bearing 37 ″, the second thrust bearing 37 ″ is provided. This will cause a problem such as seizure of, and shortening of life. Therefore, it is necessary to reduce the thrust load applied to the second thrust bearing 37 ″ as much as possible. For this reason, it has been considered to supply high-pressure lubricating oil to the second thrust bearing 37 ″.

In this case, the second thrust bearing 37 "
Is applied with a pressure of the lubricating oil that gradually decreases from the high pressure Pd on the outer peripheral surface to the low pressure Ps on the inner peripheral surface, and the upward biasing force F1 corresponds to the pressure indicated by the diagonal lines in the pressure characteristic of FIG. It becomes the integrated size.

On the other hand, in the second thrust bearings 37, 37 'according to the present invention, the grooves 37b, 37b'.
Since the high-pressure lubricating oil is supplied to the annular oil grooves 37a, 37a, the pressure becomes high Pd, and the pressure characteristics shown in FIG. 4 are obtained. Therefore, the upward biasing force F2 becomes larger than the above-mentioned F1, and the thrust is increased. The load can be considerably reduced.

[0026]

As described above, according to the present invention, the annular oil groove and the annular oil groove are provided in the annular thrust bearing which is arranged between the drive shaft and the block and receives the thrust load applied to the drive shaft. A groove extending to the outer peripheral surface is formed, and high-pressure lubricating oil from the lubricating oil introducing hole is supplied to the annular oil groove through this groove, so that the drive shaft is brought into contact with the thrust bearing and the drive shaft. Since the urging force that urges the thrust bearing acts, the load on the thrust bearing can be reduced, which can prevent seizure of the thrust bearing and improve the durability of the thrust bearing.

[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 plan view (a) and a side view (b) of a thrust bearing according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram illustrating a biasing force when an annular oil groove and a groove are not formed.

FIG. 4 is an explanatory diagram illustrating a biasing force when an annular oil groove and a groove are formed.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 scroll type compressor 6 hermetic case 8 electric motor 10 drive shaft 11 rotor 13 stator 18 block 22 fixed scroll member 23 rocking scroll member 26 (first) thrust bearing 34 high pressure chamber 35 oil sump 36 lubricating oil introduction hole 37, 37 'Thrust bearing (second thrust bearing) 37a, 37a' Annular oil groove 37b, 37b 'Groove

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

Claims (1)

[Claims] 1. An electric motor arranged in a high-pressure space in a hermetically sealed case, the electric motor comprising a stator fixed to the hermetically sealed case and a rotor fixed to a drive shaft, and an oscillator mounted eccentrically on the drive shaft. A dynamic scroll member, a fixed scroll member that meshes with the orbiting scroll member to form a compression chamber, the fixed scroll member is fixed in a closed case, and the orbiting scroll member is rotatable with the fixed scroll member. A block sandwiched between the drive shaft and the drive shaft, and an annular thrust bearing arranged between the drive shaft and the block for receiving a thrust load applied to the drive shaft; formed on the block; formed near the thrust bearing and below the high pressure chamber. A scroll-type compressor having a lubricating oil introduction hole communicating with an oil reservoir, wherein the thrust bearing is in sliding contact with the drive shaft. Forming an annular oil groove on the surface and forming a groove communicating the annular oil groove with the outer peripheral side surface, and supplying high-pressure lubricating oil from the lubricating oil introducing hole to the annular oil groove via this groove. Scroll type compressor.