JP4298829B2 - Scroll compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a scroll compressor suitable as a refrigerant compressor for refrigeration and air conditioning, and an air or other gas compressor.
[0002]
[Prior art]
Bearing oil supply in a scroll compressor provided with bearings on the upper side and the lower side of the electric motor section is described in Japanese Patent Laid-Open No. 3-37390.
[0003]
[Problems to be solved by the invention]
As shown in FIG. 6 of the prior art described above, when bearings are provided on the upper side and the lower side of the electric motor, respectively, an advantage is that the rotation of the rotating shaft and the inclination of the shaft are reduced, and stable operation can be performed in a wide rotational speed range. Is obtained. However, in the structure in which the oil contained in the discharge gas supplies oil to the main bearing and the auxiliary bearing on the opposite side as in this prior art, the refrigerant circulation amount changes depending on the operating conditions, and accordingly the speed of the discharge gas As a result, the amount of oil carried changes, and the degree of separation from the discharge gas around the main and sub-bearings changes, so the amount of oil is not stable and flaking, galling, and seizure occur due to insufficient oil supply. There was a risk.
[0004]
The present invention has been made in view of the above-described problems, and its purpose is to achieve stable operation in a wide rotational speed range by configuring the sub-bearing portion of the main and sub-bearing portions with ball or roller bearings. Another object of the present invention is to provide a scroll compressor that can reliably supply oil to a main bearing and a sub-bearing on the upper side and the lower side of an electric motor section even if the circulation amount of a refrigerant or the like changes depending on operating conditions.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, a scroll compressor according to the present invention is characterized by what is stated in claims 1 to 3, and in particular according to the invention according to claim 1 as an independent claim. The scroll compressor is a compression in which a fixed scroll and an orbiting scroll in which a spiral wrap is placed upright on a base plate are meshed with each other, and the back surface of the orbiting scroll is engaged with a crankpin portion of a rotary shaft inside a sealed container. A motor unit that is below the compressor unit and drives the rotating shaft, and a main bearing unit and a sub-bearing unit that are disposed above and below the motor unit and support the rotating shaft. An oil supply means for supplying lubricating oil to the main bearing portion through an oil supply hole provided in the rotary shaft from an oil reservoir inside or outside the sealed container, A bearing in the sub-bearing portion with constituting a bearing having rolling elements such as balls or rollers, a seal member provided between the rotary shaft and the shaft受凾for accommodating the ball or roller bearings, the shaft受凾internal the It sealed against the discharge pressure internal portion space in the closed container of the bearing凾外portion, the gap between the rolling elements of the ball or roller bearings, lubrication inside the sealed container or external oil reservoir and the rotation in the shaft It is characterized by being a part of an oil supply passage connecting the holes.
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the scroll compressor according to the present invention will be described below.
[0007]
FIG. 1 is a cross-sectional view of a scroll compressor. Inside the airtight container 9, a compressor unit 6 is disposed above, a motor unit 8 is disposed below the compressor unit 6, and an oil sump 12 is disposed below the compressor unit 6, and the compressor unit 6 and the motor are disposed via the rotary shaft 3. The part 8 is connected. The compressor unit 6 is formed with a fixed scroll 1 in which a spiral wrap 1b is erected on a base plate 1a and a revolving scroll 2 in which a spiral wrap 2b is erected on a base plate 2a by meshing the wraps with each other. The fixed scroll 1 is provided with a suction port 1c and a discharge port 1d. The rotating shaft 3 is supported by a main bearing portion 7 and a sub-bearing portion 10 that are respectively arranged on the upper side and the lower side of the electric motor unit 8. The auxiliary bearing portion 10 is fixed to the hermetic container 9 via the lower frame 9d. A crankpin portion 3 a is provided at the tip of the rotary shaft 3, and the crankpin portion 3 a is inserted into a boss 2 c protruding below the base plate 2 a of the orbiting scroll 2. A slewing bearing 2e is provided in the boss 2c, and has a structure that slides with the crankpin portion 3a. An Oldham joint 5 is disposed on the back surface of the base plate 2 a of the orbiting scroll 2. The Oldham joint 5 constitutes an anti-rotation mechanism that makes the orbiting scroll 2 orbit with respect to the fixed scroll 1 without rotating.
[0008]
When the crankpin portion 3a rotates eccentrically by the rotation of the rotary shaft 3 connected to the motor portion 8, the compressor portion 6 turns without turning the orbiting scroll 2 relative to the fixed scroll 1 by the rotation prevention mechanism of the Oldham joint 5. The gas is sucked into the sealed chamber formed by the fixed scroll wrap 1a and the orbiting scroll wrap 2a through the suction pipe 9a and the suction port 1c. Due to the swivel motion, the sealed chamber moves to the central portion and the volume is reduced to compress the gas, and the compressed gas is discharged from the discharge port 1d to the discharge chamber 9c. The gas discharged into the discharge chamber 9c circulates in the discharge pressure internal space 9e around the compressor unit 6 and the motor unit 8, and then is discharged from the discharge pipe 9b to the outside of the compressor.
[0009]
Next, the oil supply path of the differential pressure oil supply method will be described. The orbiting scroll base plate 2a is provided with a back pressure hole 2d for communicating a compression chamber formed by combining wraps with the back pressure chamber 4c on the back of the orbiting scroll base plate 2a. (Back pressure) is maintained at an intermediate pressure between the suction pressure and the discharge pressure. A seal bearing portion 4b provided on the frame 4 prevents discharge gas from flowing into the back pressure chamber 4c. On the other hand, the oil reservoir 12 is under a discharge pressure, and a system for supplying oil using a differential pressure between the discharge pressure and the back pressure is a differential pressure oil supply system. FIG. 2 is an enlarged cross-sectional view in the vicinity of the auxiliary bearing portion 10. The auxiliary bearing portion 10 is assembled with a ball bearing 10a inside the bearing rod 10d , and a seal member 10c for sealing the ball bearing 10a against the discharge pressure internal space 9e in the sealed container 9 is provided above the ball bearing 10a. It has a structure prepared for. The rotating shaft 3 is provided with a lateral hole 3c penetrating the oil supply hole 3b in the rotating shaft direction at the upper part of the fitting portion with the ball bearing 10a. A closing member 3 d is incorporated at the lower end of the rotating shaft 3. The oil in the oil sump 12 enters the bearing rod 10d through the oil supply pipe 11 fixed to the bearing rod 10d, passes through the rolling elements 10b while lubricating the ball bearing 10a, and passes to the upper portion of the ball bearing 10a. The oil supply hole 3b enters from 3c. The seal member 10c prevents the refrigerant gas from entering from the outside of the bearing rod 10d or the oil from flowing out from the inside of the bearing rod 10d. The oil that has entered the oil supply hole 3b enters the back pressure chamber 4c through a path passing through the bearing clearance of the slewing bearing 2e and two paths passing through the bearing clearance of the seal bearing portion 4b and the main bearing portion 7 from the lateral hole 3e. The oil that has entered the back pressure chamber 4c enters the compression chamber through the back pressure hole 2d and is discharged into the discharge chamber 9c of the sealed container 9 together with the refrigerant gas compressed from the discharge port 1d. The oil is separated from the refrigerant gas in the discharge pressure internal space 9 e of the sealed container 9 and returns to the oil reservoir 12.
[0010]
FIG. 3 shows an example in which an oil reservoir is provided outside. An oil tank 13 is provided outside the sealed container 9, and an oil reservoir 13a in the oil tank 13 and a bearing rod 10d of the auxiliary bearing portion 10 are connected by an oil pipe 13b and an oil supply pipe 13c. The upper space 13d of the oil reservoir 13a of the oil tank 13 and the discharge pipe 9b of the sealed container 9 are connected by a discharge pipe 13e. The pressure in the oil tank 13 is a discharge pressure, and the oil in the oil reservoir 13a is guided to the bearing rod 10d through the oil pipe 13b by the differential pressure between the discharge pressure and the back pressure. The oil path from the bearing rod 10d to the discharge pipe 9b is the same as in the above example. The oil discharged into the hermetic container 9 passes through the discharge pipe 13e together with the refrigerant gas and enters the oil tank 13, where it is separated from the refrigerant gas and returns to the oil reservoir 13a.
[0011]
FIG. 4 is an example in which the auxiliary bearing portion 10 is configured by a roller bearing 10a. As with the ball bearing 10a, the oil passes between the rolling elements 10b and escapes from the bottom to the top while lubricating the roller bearing 10a. The oil that has fallen into the upper part of the roller bearing 10a enters the oil supply hole 3b through the lateral hole 3c.
[0012]
FIG. 5 shows an example in which an oil supply pump 14 is incorporated in the lower part of the bearing rod 10a. The oil in the oil reservoir 12 is guided into the bearing rod 10d by the oil supply pump 14, and enters the oil supply hole 3b as in the above example. In the present embodiment, the pressure in the sealed container can be configured with either the suction pressure or the discharge pressure.
[0013]
【The invention's effect】
According to the present invention, by configuring the auxiliary bearing portion of the main auxiliary auxiliary bearing portion with a ball or a roller bearing, stable operation can be performed in a wide rotational speed range, and the circulation amount of the refrigerant or the like changes depending on the operation conditions. In addition, oil supply to the main and sub bearing parts can be ensured, and flaking, galling and seizure of the ball or roller bearing due to insufficient oil supply can be prevented, and a highly reliable scroll compressor can be provided.
[Brief description of the drawings]
FIG. 1 shows a cross-sectional view of a scroll compressor according to a first embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a sub bearing portion in the first embodiment of the present invention.
FIG. 3 shows a scroll compressor and external oil tank system diagram according to a second embodiment of the present invention.
FIG. 4 is an enlarged sectional view of a sub-bearing portion in a third embodiment of the present invention.
FIG. 5 is an enlarged cross-sectional view of a secondary bearing portion in a fourth embodiment of the present invention.
FIG. 6 is a cross-sectional view of a conventional scroll compressor provided with main and sub both bearings.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Fixed scroll 1a ... Base plate 1b ... Lap 1c ... Suction port 1d ... Discharge port 2 ... Orbiting scroll 2a ... Base plate 2b ... Wrap 2c ... Boss 2d ... Back pressure hole 2e ... Swivel bearing 3 ... Rotating shaft 3a ... Crank pin Portion 3b ... Oil supply hole 3c ... Horizontal hole 3d ... Close member 3e ... Horizontal hole 4 ... Frame 4a ... Bearing flange 4b ... Seal bearing portion 4c ... Back pressure chamber 5 ... Oldham joint 6 ... Compressor portion 7 ... Main bearing portion 7a ... Roller bearing 8 ... Electric motor part 9 ... Sealed container 9a ... Suction pipe 9b ... Discharge pipe 9c ... Discharge chamber 9d ... Lower frame 9e ... Discharge pressure inner space 10 ... Sub-bearing part 10a ... Ball or roller bearing 10b ... Rolling element 10c ... Seal member 10d ... Bearing shaft 10e ... Bolt 11 ... Oil supply pipe 12 ... Oil reservoir 13 ... Oil tank 13a ... Oil reservoir 13b ... Oil pipe 13d ... Oil supply pipe 13d ... Upper space 13e ... Discharge pipe 13f ... Discharge pipe 14 ... Oil supply pump

Claims (3)

A compressor part in which a fixed scroll and a turning scroll in which a spiral wrap is placed upright on a base plate are engaged with each other inside the sealed container, and the back surface of the base plate of the orbiting scroll is engaged with the crankpin part of the rotary shaft, An electric motor section that is below the compressor section and drives the rotary shaft; a main bearing section and an auxiliary bearing section that are disposed above and below the electric motor section to support the rotary shaft; and In a scroll compressor comprising: an oil supply means for supplying lubricating oil to the main bearing portion through an oil supply hole provided in the rotary shaft from an internal or external oil reservoir,
The bearing in the sub-bearing portion is constituted by a bearing having rolling elements such as balls or rollers, and a seal member is provided between the bearing rod housing the ball or roller bearing and the rotating shaft, and the inside of the bearing rod is It seals with respect to the discharge pressure internal space in the said airtight container in the outside of this bearing rod, and the clearance gap between the said rolling elements of this ball | bowl or a roller bearing is the oil reservoir inside the said airtight container, or the outside in the said rotating shaft. A scroll compressor characterized by being a part of an oil supply passage connecting the oil supply holes.   The scroll compressor according to claim 1, wherein the oil supply means is a differential pressure oil supply means using a differential pressure between an intermediate pressure during compression in the compressor section and a discharge pressure in the oil reservoir.   The scroll compressor according to claim 1, wherein the oil supply means is pump oil supply means directly connected to a lower end of the rotating shaft.

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