JPH11324944A - Scroll compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the lubricating oil from flowing out to an external of a compressor and prevent the lubrication failure and the seizure caused by the shortage of the lubricating oil by mounting a permanent magnet on one of a revolving scroll end plate and a thrust face opposite thereto, mounting a magnetic body on the other one, and making flow the magnetic fluid including the lubricating oil as the base oil between both to form a magnetic fluid bearing. SOLUTION: A magnetic body 92 is mounted on a revolving scroll end plate 21 and a permanent magnet 91 is mounted on a thrust face 64 to form a magnetic fluid bearing structure therebetween. The porous materials 93 are respectively mounted on an inner peripheral side of the magnetic member 92 and an inner peripheral side of the permanent magnet 91. By sealing a space between a balance weight chamber 61 and an inlet cavity 16 by the magnetic fluid bearing structure, the flowing out of the lubricating oil 81 to an external of a compressor through the inlet cavity 16 can be prevented. Further as the porous materials 93 store the lubricating oil 81, the lubricating state can be properly kept at all times.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor in which an electric motor and a scroll compressor are connected to each other by a rotating shaft.

[0002]

2. Description of the Related Art FIGS. 3 and 4 are a longitudinal sectional view of a conventional scroll compressor and a longitudinal sectional view around a thrust bearing. In the figure, a scroll-type compression mechanism is provided at an upper portion inside a housing 8, and an electric motor 4 is provided at a lower portion, and these are linked to each other by a rotating shaft 5. The scroll-type compression mechanism includes a fixed scroll 1, a revolving scroll 2, an Oldham ring 3 that allows the revolving orbiting motion of the revolving scroll 2 but prevents its rotation, a frame 6 on which the fixed scroll 1 and the electric motor 4 are locked, and a rotating shaft. Upper bearing 71 and lower bearing 72 for supporting the orbit 5, orbiting bearing 73 and thrust bearing 74 for supporting the orbiting scroll 2
Etc. are provided.

[0003] The fixed scroll 1 is a fixed scroll end plate 1.
1 and a fixed scroll spiral wrap 1 erected on the inner surface thereof
2, a discharge port 13 and a discharge valve 17 for opening and closing the discharge port 13 are provided at the center of the fixed scroll end plate 11. The orbiting scroll 2 includes an orbiting scroll end plate 21,
Orbiting scroll spiral wrap 22 erected on its inner surface
And a boss 23 protruding from the center of the outer surface of the orbiting scroll end plate 21. A drive bush 54 is fitted in the boss 23 and is rotatably supported via an orbiting bearing 73. A slide groove 55 is formed in the drive bush 54, and an eccentric drive pin 53 projecting from the upper end surface of the rotary shaft 5 is slidably fitted in the slide groove 55. At the lower end of the drive bush 54, a balance weight 63 for balancing dynamic imbalance due to the revolving orbiting motion of the orbiting scroll 2 is fixed.

The lubricating oil 81 stored in the inner bottom of the housing 8 is sucked up from the inlet hole 51 by centrifugal force due to the rotation of the rotary shaft 5, passes through the oil supply hole 52, and the lower bearing 72, the upper bearing 71, and the drive bush 54. After being lubricated, it is discharged to the bottom of the housing 8 through the balance weight chamber 61 and the oil drain hole 62. When the electric motor 4 is driven, the rotational torque is transmitted to the orbiting scroll 2 via the rotating shaft 5, the eccentric drive pin 53, the drive bush 54, and the orbiting bearing 73, and the orbiting scroll 2 is prevented from rotating by the Oldham link 3. While revolving around.

[0005] By the orbiting motion of the orbiting scroll 2, the compressed gas enters the housing 8 via the suction pipe 82 and cools the electric motor 4, and then from the suction passage 15, the spiral wraps 12 and 22 of the fixed scroll 1 and the orbiting scroll 2. Through a suction cavity 16 formed therearound, it is sucked into a plurality of sealed spaces 24 formed by meshing the fixed scroll 1 and the orbiting scroll 2. The closed space 2 is formed by the orbital movement of the orbiting scroll 2.
As the volume of 4 decreases, it reaches the center while being compressed, and from here it is discharged through a discharge port 13 to a discharge cavity 14 formed on the back side of the fixed scroll end plate 11 by pushing up a discharge valve 17, Further, it is discharged outside through the discharge hole 18 and the discharge pipe 83.

At the same time, the lubricating oil 81 stored in the oil reservoir at the inner bottom of the sealed housing 8 is
1 and is supplied to a revolving turning mechanism including a lower bearing 72, an upper bearing 71, an eccentric drive pin 53, a drive bush 54, a turning bearing 73 and the like through an oil supply hole 52 formed in the rotating shaft 5. Lubricate these.

The lubricating oil 81 that has lubricated the orbital turning mechanism and the lubricating oil 81 that has flowed through the slide groove 55 enter the balance weight chamber 61 formed at the center of the upper surface of the frame 6. A part of the lubricating oil 81 that has entered the balance weight chamber 61 enters the oil supply groove 65 formed in the thrust surface 64, and in the course of flowing through the oil supply groove 65, the orbiting scroll 2 revolves around the thrust surface 64. It is pulled out to lubricate the thrust surface 64. The lubricating oil that has flowed through the oil supply groove 65 and the lubricating oil that has lubricated the thrust surface 64 flow out from the outer peripheral edge of the thrust surface 64 to lubricate the Oldham ring 3. On the other hand, the surplus lubricating oil that has entered the balance weight chamber 61 returns to the bottom of the housing 8 through the oil drain hole 62.

At this time, when the rotation speed of the rotating shaft 5 increases, the centrifugal force due to the rotation of the rotating shaft 5 increases,
The amount of the lubricating oil 81 sucked up from the inlet hole 51 increases. As a result, the amount of lubricating oil for lubricating the lower bearing 72, the upper bearing 71, and the drive bush 54 increases, and a large amount of lubricating oil 81 accumulates in the balance weight chamber 61.

The oil accumulated in the balance weight chamber 61 is
Although part of the lubricating oil 81 is discharged to the bottom of the housing 8 through the oil drain hole 62, the other lubricating oil 81 passes through the sliding surface between the thrust bearing 74 and the back surface of the orbiting scroll end plate 21, and It flows out to the suction cavity 16 from the clearance of the mating surface with the orbiting scroll end plate 21. Suction cavity 1
The lubricating oil 81 that has flowed out to the compressor 6 is discharged to the outside of the compressor together with the compressed gas, and the amount of the lubricating oil 81 stored at the bottom of the housing 8 gradually decreases, resulting in poor lubrication or poor lubrication. An accident such as seizure may occur.

For this reason, as described in Japanese Patent Application Laid-Open No. 5-149275, an annular oil seal groove 76 is provided on the back surface of the orbiting scroll end plate, and an oil seal material 75 is provided in the groove. At least one surface of the thrust bearing blocks the inner and outer oil passages. The oil accumulated in the oil sump in this manner is removed by the oil seal member 75 disposed in the oil seal groove 76 of the orbiting scroll end plate.
Outflow to the suction cavity 16 is prevented.

Japanese Patent Application Laid-Open No. Hei 6-10872 discloses that
When the frequency of the current supplied to the electric motor 4 is increased or decreased by an inverter to increase or decrease the rotation speed, the inlet hole 51
A method is disclosed in which an inverted U-shaped siphon pipe is connected to the outlet of the oil drain hole 62 and the top of the siphon pipe is located above the thrust surface 64 in order to suppress fluctuations in the flow rate of the lubricating oil 81 sucked up from the pipe. Have been.

In addition, as a dynamic pressure bearing device, there is disclosed a Japanese Utility Model Application Laid-Open No.
There is a hydrodynamic bearing device which uses an attractive force of a permanent magnet and maintains an axial position constant using a permanent magnet and a magnetic fluid as disclosed in Japanese Patent No. 67819.

[0013]

However, the above-mentioned scroll compressor has the following disadvantages.

First, in the prior art described in Japanese Patent Application Laid-Open No. 5-149275, (1) an oil seal member 75 disposed in an oil seal groove 76 of an end plate is brought into contact with a thrust surface 64 to slide. As a result, the sliding friction loss increases, and as a result, the efficiency of the compressor decreases.

When the frequency of the current supplied to the electric motor 4 is increased or decreased by an inverter to increase or decrease the rotation speed,
As a result, the lubricating oil 81 sucked up from the inlet hole 51
Fluctuates. Therefore, during low-speed rotation, the amount of the lubricating oil 81 supplied to the thrust surface 64 decreases, and poor lubrication on the thrust surface 64 occurs.

Next, in the prior art described in Japanese Patent Application Laid-Open No. 6-10872, it is necessary to position the top of the siphon tube above the thrust surface 64. The supply amount of oil 81 cannot be adjusted.

Furthermore, in the prior art described in Japanese Utility Model Laid-Open No. 5-67819, (4) the permanent magnets are concentric with a slight gap so that the magnetic poles of the permanent magnets are parallel to the axial direction. And the structure in which the position in the axial direction is kept constant by the attraction force of the permanent magnets, the refrigerant pressure changes depending on the operating conditions as in the case of a compressor, and the orbiting scroll spiral wrap 22 It is inconvenient when moving in the direction.

[0018]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and as a means for solving the above-mentioned problems, according to the first aspect of the present invention, the electric motor and the scroll type compressor are constituted by a rotary shaft. In a scroll compressor in which the scroll type compressor is provided with a fixed scroll, an orbiting scroll, and an Oldham ring, one of an orbiting scroll end plate constituting the orbiting scroll and a thrust surface opposed to the orbiting scroll end plate. A magnetic fluid is arranged by disposing a permanent magnet on the other side, disposing a magnetic body on the other side, and injecting a magnetic fluid based on lubricating oil of a scroll compressor between the permanent magnet and the magnetic body. It is characterized by the following.

According to a second aspect of the present invention, in the scroll compressor according to the first aspect, the permanent magnet and the magnetic body are formed in an annular shape concentric with a center axis of the electric motor.
Further, a porous material is provided on the inner peripheral side or the outer peripheral side of the permanent magnet and the magnetic body.

According to a third aspect of the present invention, in the scroll compressor according to the first aspect, the width of the permanent magnet or the magnetic body provided on the orbiting scroll end plate is set on the thrust surface. Alternatively, it is characterized in that it is wider by at least the orbital diameter of the orbiting scroll than the width of the permanent magnet.

According to a fourth aspect of the present invention, in the scroll compressor according to the first aspect, an Oldham ring is disposed between the orbiting scroll end plate and the thrust surface, and the orbiting scroll end plate and the Oldham ring are disposed. A magnetic fluid bearing is disposed between the thrust surface and the Oldham ring.

According to the first aspect of the present invention, since the oil seal is provided by the magnetic fluid bearing structure formed between the orbiting scroll end plate and the thrust surface facing the orbiting scroll end plate, the lubricating oil is compressed through the suction cavity. It does not flow out of the machine and does not cause poor lubrication or seizure due to insufficient lubricating oil. Furthermore, since a magnetic fluid using the lubricating oil of a scroll compressor as a base oil is used, even if the base oil decreases due to evaporation due to a rise in temperature, the lubricating oil is supplied from the bottom of the housing. Can be maintained.

According to the second aspect of the present invention, a porous material is disposed on at least one of the orbiting scroll end plate and the thrust surface constituting the magnetic fluid bearing.
Since the lubricating oil is stored in the porous material when the electric motor is rotating at high speed, the lubricating oil is supplied from the porous material to the magnetic fluid bearing structure at the start of operation or at low speed, so that the lubrication on the thrust surface 4 is performed. Defects can be prevented. Further, a fluid film is formed on the ferrofluid bearing structure by a magnetic fluid, and fluid lubrication is performed without direct contact between the orbiting scroll end plate and the thrust surface, so that sliding friction loss can be reduced.

According to the third and fourth aspects of the present invention, the permanent magnet and the magnetic body are formed in an annular shape, or the width of the permanent magnet or the magnetic body disposed on the orbiting scroll by a length that the orbiting scroll moves by the orbital orbital motion. The structure of the magnetic fluid bearing part becomes a shape suitable for the scroll revolving orbiting motion by making the width larger than the width of the magnetic material or permanent magnet disposed on the thrust surface, and configuring the Oldham ring with a magnetic material. The bearing structure can be simplified.

Since the magnetic fluid bearing structure is used, the magnetic fluid is always held between the orbiting scroll end plate and the thrust surface by the magnetic force of the permanent magnet.
There is no limitation on the installation direction of the compressor body, and the compressor can be a horizontal scroll compressor.

[0026]

FIG. 1 shows a first embodiment of a scroll compressor according to the present invention in which a magnetic fluid bearing structure is formed between an orbiting scroll end plate 21 and a thrust surface 64. FIG. In the first embodiment, the shape of the permanent magnet 91 and the magnetic body 92 is an annular shape concentric with the center axis of the electric motor 4, and the annular width (W1) of the magnetic body 92 provided on the orbiting scroll end plate 21.
Is the annular width (W2) of the permanent magnet 91 disposed on the thrust surface 64 and the length (W) of the orbital diameter of the orbiting scroll 2.
It is formed so as to be equal to or greater than the sum of 3). At this time, the orbiting scroll end plate 21 and the frame 6 are made of a non-magnetic material such as aluminum. In this embodiment, the magnetic body 92 provided on the orbiting scroll end plate 21
And a porous material 93 is disposed on the inner peripheral side of the permanent magnet 91 disposed on the thrust surface 64. The porous material 93 may be provided only on one of the permanent magnets or on the outer side of the magnetic body, and the porous material 93 may be provided on the outer peripheral side. The structure of Example 1 is most preferable. Further, in this embodiment, the magnetic body 92 is provided on the orbiting scroll end plate 21 and the thrust surface 6 is provided.
Although the permanent magnets 91 are provided in 4, it is of course possible to replace the magnetic material with the permanent magnets, or to use both permanent magnets. The configuration of the other parts is the same as the conventional one shown in FIG.

The flow of the compressed gas in this embodiment is the same as that in FIG. 3, and the flow of the lubricating oil 81 is as follows. The lubricating oil 81 stored at the bottom of the housing 8 is sucked up by the centrifugal force of the rotating shaft 5,
The lower bearing 72, the upper bearing 71, the eccentric drive pin 53, the drive bush 54,
It is supplied to a revolving turning mechanism including a turning bearing 73 and the like to lubricate them. The lubricating oil 81 that has lubricated the orbital turning mechanism and the lubricating oil 81 that has flowed through the slide groove 55 enter the balance weight chamber 61 formed at the center of the upper surface of the frame 6. Part of the lubricating oil 81 that has entered the balance weight chamber 61 enters an oil supply groove 65 formed in the thrust surface 64,
In the course of flowing through the oil supply groove 65, the revolving orbiting motion of the orbiting scroll 2 lubricates the Oldham ring 3 and is drawn out to the thrust surface 64 to lubricate the thrust surface 64. At this time, the magnetic body 92 disposed on the orbiting scroll end plate 21 moves in the radial direction from the center axis of the electric motor 4 by the distance of the orbital diameter. The magnetic fluid 9 is held between the permanent magnet 91 and the magnetic body 92 by the magnetic force of the permanent magnet 91. However, since the annular width of the magnetic body 92 is increased by the distance of the orbital diameter, the orbiting scroll 2 revolves. The permanent magnet 91 and the magnetic body 92 always keep a state of facing each other even if they make a turning movement. Therefore, a magnetic fluid bearing is formed therebetween.

At this time, the space between the balance weight chamber 61 and the suction cavity 16 is sealed by a magnetic fluid bearing structure, and the lubricating oil 81 does not flow out of the compressor through the suction cavity 16.
It does not cause poor lubrication or seizure due to lack of oil. Since the lubricating oil 81 is stored in the porous material 93, even when the lubricating oil 81 supplied from the bottom of the housing 8 is small at the time of low speed rotation such as at the start of operation, the lubricating oil 81 is stored in the porous material 93. By supplying 81, a good lubrication state can be maintained. In the magnetic fluid bearing structure, the magnetic fluid 9 is used.
Since the fluid film is formed, the orbiting scroll end plate 21 and the thrust surface 64 are fluidly lubricated without directly contacting with each other, so that sliding friction loss can be reduced. That is, in the magnetic fluid bearing structure, the two functions of the thrust bearing and the oil seal are simultaneously performed. Further, since the magnetic fluid 9 using the lubricating oil 81 of the scroll compressor as the base oil is used, even if the base oil decreases due to evaporation or the like due to temperature rise, the lubricating oil 81 is supplied from the bottom of the housing 8. The ferrofluid structure can be maintained. On the other hand, the surplus lubricating oil that has entered the balance weight chamber 61 returns to the bottom of the housing 8 through the oil drain hole 62.

FIG. 2 shows a second embodiment of the magnetic fluid bearing structure of the present invention. In the present embodiment, the Oldham ring 3 and the magnetic body 92 in the first embodiment are integrated, and a permanent magnet 91 is disposed on each of the thrust surface 64 and the orbiting scroll end plate 21 facing the Oldham ring 3. .
At this time, the magnetic fluid 9 forms a magnetic fluid bearing between the thrust surface 64 and the Oldham ring 3, and between the orbiting scroll end plate 21 and the Oldham ring 3, respectively. In this manner, the Oldham ring 3 has a function of preventing rotation of the orbiting scroll 2, a function of a thrust bearing, and a function of an oil seal. The configuration of the other parts, the flow of the compressed gas, and the flow of the lubricating oil 81 are the same as in the first embodiment.

[0030]

As described above, the present invention has the following effects.

The orbiting scroll end plate 21 and the thrust surface 64
To form a lubricating oil 81
Can be prevented from flowing out of the compressor through the suction cavity 16.

The orbiting scroll end plate 21 and the thrust surface 64
Forming a ferrofluid bearing between the boundary lubrication state and the boundary lubrication state including contact between solids (friction coefficient 0.0
From about 1 to 1.0) to fluid lubrication (friction coefficient about 0.002). In the conventional scroll compressor, the friction loss of the thrust bearing portion is about 25% of the friction loss of the entire compressor.
% (The amount of friction loss is about 30 W), but by employing a magnetic fluid bearing structure, sliding friction loss is reduced to 1/5 or less, and the efficiency of the compressor is improved.

By using the lubricating oil 81 of the scroll compressor as the base oil of the magnetic fluid 9, the lubricating oil 81 is supplied from the bottom of the housing 8 even if the base oil decreases due to evaporation due to temperature rise. The ferrofluid structure can be maintained.

Since the lubricating oil 81 is stored in the porous material 93, the lubricating oil 81 is supplied from the porous material 93 to the magnetic fluid bearing structure at the start of operation or at a low speed so that the thrust surface 6
4 can prevent poor lubrication.

In the magnetic fluid bearing, since the magnetic fluid 9 is held by the magnetic force of the permanent magnet 91, there is no restriction on the installation direction of the compressor body, and the compressor can be a horizontal scroll compressor.

[Brief description of the drawings]

FIG. 1 shows a configuration diagram of a first embodiment of the present invention.

FIG. 2 shows a configuration diagram of a second embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of a conventional scroll compressor.

FIG. 4 is a longitudinal sectional view showing the vicinity of a thrust bearing of a conventional scroll compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fixed scroll 2 Orbiting scroll 3 Oldham ring 4 Electric motor 5 Rotating shaft 6 Frame 7 Bearing 8 Housing 9 Magnetic fluid 11 Fixed scroll end plate 12 Fixed scroll spiral wrap 13 Discharge port 14 Discharge cavity 15 Intake passage 16 Suction cavity 21 Orbital scroll end Plate 22 Orbiting scroll spiral wrap 23 Boss 53 Eccentric drive pin 54 Drive bush 61 Balance weight chamber 64 Thrust surface 65 Oil supply groove 81 Lubricating oil 82 Suction pipe 83 Discharge pipe 91 Permanent magnet 92 Magnetic body 93 Porous material

Claims (4)

[Claims] 1. A scroll compressor comprising an electric motor and a scroll compressor interlocked by a rotating shaft, wherein the scroll compressor includes a fixed scroll, a orbiting scroll, and an Oldham ring. A permanent magnet is provided on one of the plate and the thrust surface facing the orbiting scroll end plate, and a magnetic material is provided on the other, and lubricating oil for a scroll compressor is provided between the permanent magnet and the magnetic material. A scroll compressor wherein a magnetic fluid bearing is formed by injecting a magnetic fluid as a base oil. 2. The permanent magnet and the magnetic body are formed in an annular shape concentric with the center axis of the electric motor, and a porous material is provided on the inner or outer peripheral side of the permanent magnet and the magnetic body. The scroll compressor according to claim 1, wherein 3. The width of a permanent magnet or a magnetic material disposed on the end plate of the orbiting scroll is made wider than the width of the magnetic material or permanent magnet disposed on the thrust surface by at least the revolving diameter of the orbiting scroll. The scroll compressor according to claim 1, wherein: 4. An Oldham ring is disposed between the orbiting scroll end plate and the thrust surface, and a magnetic fluid bearing is disposed between the orbiting scroll end plate and the Oldham ring and between the thrust surface and the Oldham ring. The scroll compressor according to claim 1, wherein: