JPH0799151B2 - Scroll compressor - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a scroll compressor that compresses a refrigerant gas or the like by engaging a pair of spiral side plates with each other and rotating one of them.

[Conventional technology]

This type of scroll compressor is used for a refrigerating device, a refrigerant compressor of an air conditioner, and the like, and is disclosed in, for example, JP-A-60-206989.
The one disclosed in the publication is constructed as shown in the longitudinal sectional view in FIG. That is, at the upper end of the closed container 2 fixed on the foot 1, a fixed scroll 3 integrally formed by a disc-shaped end plate 3a and a scroll side plate 3b protruding from the lower surface thereof is provided. The upper bearing frame 4 is fixed to the upper bearing frame 4 on one side with a plurality of bolts 5. The upper bearing frame 4 and the lower bearing frame 6 integrally connected to the upper bearing frame 4 have a main shaft 7 and an upper main bearing 8 and a lower portion. It is rotatably supported via the main bearing 9. Reference numeral 10 denotes a motor / stator formed in a cylindrical shape and fixed to the lower bearing frame 6 with a plurality of bolts 11.
A motor rotor 12 fixed to the main shaft 7 by press fitting, shrink fitting, etc. is fitted, and the main shaft 7 is configured to rotate via the motor rotor 12 by energizing the motor. Reference numeral 13 denotes an oil cap that is inserted into a hole of a cover 15 that covers an oil sump 14 below the closed container 2 and is fixed to the lower end of the main shaft 7 by press fitting, shrink fitting, etc., and the suction port 13a at the lower end thereof is the oil sump. Opened into oil 16 stored in 14.

An eccentric hole 7a having an axis eccentric with respect to the axis of the main shaft 7, that is, the axis of the upper main bearing 8 is formed at the upper end of the main shaft 7. An orbiting scroll shaft 17a indicated by is rotatably supported by an orbiting bearing 18. The orbiting scroll 17 includes a base plate 17b integrally formed with the shaft 17a, and the top surface of the base plate 17b is
A scroll side plate 17c, which is formed in a spiral shape and engages with the scroll side plate 3b of the fixed scroll 3, is provided in a protruding manner. A suction port 20 and a discharge port 21 are formed in the outer peripheral portion and the central portion of the crescent-shaped compression chamber 19 formed between the scroll side plates 3b and 17c, respectively. It is connected to a device outside the machine via a suction pipe 2a and a discharge pipe 22. Reference numeral 23 is a concentric circular thrust bearing that contacts the inner circumference of the upper main bearing 8 and extends outward.
An Oldham coupling 24 is provided between the orbiting scroll 17 and the upper bearing frame 4 to regulate the rotation of the orbiting scroll 17.

An eccentric portion with respect to the axis of the main shaft 7 is provided with an oil supply hole 25 opened at the lower end into the oil cap 13 in the axial direction. The oil supply hole 25 communicates with the eccentric hole 7a. Through the oil hole 26, the inside of the oil sump 14, the rocking bearing 18, the lower main bearing 9
And communicate with each other.

With the above configuration, when the main shaft 7 rotates due to the driving force generated by the motor-stator 10 and the motor-rotor 12 when the motor is energized, the orbiting scroll 17
Is revolved by the eccentric action while the rotation is regulated by the Oldham coupling 24, and the refrigerant gas sucked from the suction pipe 2a cools the motor rotor 12 and the motor stator 10, and then revolves around the scroll side plate of the orbiting scroll 17. It is taken into the compression chamber 19 formed between the stationary scroll 3 and the scroll side plate 3b of the stationary scroll 3 from the suction port 20 and compressed. The compressed refrigerant gas is discharged from the discharge pipe 22 to the outside of the compressor through the discharge port 21.

When the main shaft 7 rotates, the centrifugal force acts on the oil sump.
The oil 16 in the oil 14 is supplied to the suction port 13a of the oil cap 13
After that, the rocking bearing 18 and the lower main bearing 9 are lubricated, and then the rocking bearing 18 is lubricated in the order of the upper main bearing 8 and the thrust bearing 23. Oil 16 which lubricated each of these bearings 18, 9, 8 and 23 is
It falls due to gravity and is returned to the oil sump 14.

[Problems to be Solved by the Invention] However, in such a conventional scroll compressor, the main shaft 7 is controlled by controlling the rotation speed by an inverter or the like.
When the number of revolutions is increased, the angular velocity of the main shaft 7 increases, the amount of oil supplied to each bearing 18, 8, 9, 23 by centrifugal action increases, and more oil 16 than required is supplied, and the refrigerant Since the circulation amount increases and the flow velocity of the refrigerant gas in the closed container 2 increases, as a result, the oil 16 after lubricating each bearing is sucked into the compression chamber 19 together with the refrigerant gas and compressed before returning to the oil sump 14. There was a problem that the oil was discharged to the outside of the machine, the amount of oil held in the compressor decreased, and the sliding part seized.

The present invention has been made to solve such problems, and it is an object of the present invention to provide a scroll compressor capable of supplying an optimum amount of oil to each bearing even if the rotation speed of a main shaft increases. Has an aim.

[Means for Solving the Problems]

In order to achieve such an object, in the present invention, a bypass hole that branches from an oil supply hole that penetrates the eccentric portion of the main shaft and opens outside the main shaft, and a valve that opens and closes this bypass hole with a predetermined hydraulic pressure from the oil supply hole. And.

[Work]

When the main shaft rotates, the oil in the oil sump is supplied to each bearing through the oil supply hole by the action of centrifugal force. When the rotational speed of the main shaft increases and the centrifugal force increases, the valve is opened by the hydraulic pressure that exceeds a predetermined pressure, and excess oil is discharged from the bypass hole and returns to the oil sump.

〔Example〕

1 and 2 show an embodiment of a scroll compressor according to the present invention, FIG. 1 is a vertical sectional view thereof, and FIG. 2 is an enlarged vertical sectional view of the vicinity of a lower portion of a main shaft. In the figure, members having the same structure as the conventional scroll compressor shown in FIG. A vertical main shaft 7 is axially supported by upper and lower main bearings 8 and 9 fixed to the closed container 2 side as a housing, and an eccentric hole 7a formed in an upper end portion of the main shaft 7 has a main shaft 7a. A shaft 17a of an orbiting scroll 17 that revolves with the rotation of 7 and compresses a refrigerant gas or the like between the fixed scroll 3 on the closed container 2 side is pivotally supported via an orbiting bearing 18. 23 is an orbiting scroll
It is a thrust bearing that receives a load of 17 in the axial direction.

An eccentric portion of the main shaft 7 with respect to the axial center thereof is provided with an oil supply hole 25 having an opening 25a at the lower end opened into the oil cap 13 and penetrating in the axial direction parallel to the axial center, and the upper end thereof is an eccentric hole.
It is opened to 7a. The oil supply hole 25 is communicated with the lower main bearing 9 by an oil passage hole 26.

In this device, a bypass hole 27 that branches off from the main shaft 7 and opens to the outside of the main shaft 7 is formed near the lower end of the oil supply hole 25.
A valve 28 is provided in the radial direction of the oil supply hole 25 on the side opposite to the shaft center, and a valve 28 for opening and closing the bypass hole 27 is provided. valve
Reference numeral 28 denotes a valve holder 29 which is formed in a hollow ring shape so as to balance the rotation and is positioned and fixed to a portion corresponding to the bypass hole 27 of the main shaft 7 by press fitting, shrink fitting, etc., and a bypass hole 27 accommodated in the valve holder 29. Of the valve seat 30 and a compression coil spring 31 that biases the valve body 30 in the closing direction of the bypass 27, and a discharge hole 32 is formed on the lower surface of the valve holder 29. It is open. The spring force of the compression coil spring 31 is set so that the valve body 30 opens when the oil 16 entering the bypass hole 27 from the oil supply hole 25 reaches a predetermined pressure.

With the above configuration, when the main shaft 7 is rotated by the driving force generated by the motor-stator 10 and the motor-rotor 12, the orbiting scroll 17 revolves eccentrically while being fixed while rotating. The refrigerant gas is compressed with the scroll 3.

When the main shaft 7 rotates, the centrifugal force acts on the oil sump.
The oil inside 14 is the same as the oil inlet 13a of the oil cap 13 and the oil supply hole 25.
Then, the rocking bearing 18 and the lower main bearing 9 are lubricated, and then the rocking bearing 18 is lubricated in the order of the upper main bearing 8 and the thrust bearing 23. Oil 16 which lubricated each of these bearings 18, 9, 8 and 23 is
It falls due to gravity and is returned to the oil sump 14.

The rotation speed is controlled by an inverter or the like, and as the rotation speed of the main shaft 7 increases, the amount of oil supplied to each bearing 18, 8, 9, 23 increases due to the centrifugal action, but at the same time, the centrifugal force also increases and the valve 28 Since the valve body 30 moves in the opening direction against the elastic force of the compression coil spring 31, a part of the oil 16 supplied to the bearings 18, 8, 9, 23 is partially bypassed by the bypass hole 27 and the discharge hole 32. Through the oil sump 14
Returned to. In this case, the spindle 7 when the valve 28 starts to open
The number of rotations and the opening degree of the valve 28 can be arbitrarily set by changing the elastic force of the compression coil spring 31.

Even if the rotational speed of the main shaft 7 increases in this way, each bearing 18,8,
The amount of oil supplied to 9,23 does not increase significantly, and due to the method of setting the elastic force of the compression coil spring 31, each bearing 18,8,9 It can be supplied to the compression chamber 19 with the suction gas.
The amount of oil sucked into the compressor and discharged to the outside of the compressor is reduced, and the amount of oil retained in the compressor does not become too small.

FIG. 3 is an enlarged vertical sectional view of the vicinity of the lower portion of the main shaft showing another embodiment of the present invention corresponding to FIG. 2. In this embodiment, the valve element 30 of the valve 28A is attached to the main shaft 7. Plate spring 33 fixed
Is biased in the closing direction by. The other constructions and effects are the same as those of the above-mentioned embodiment.

〔The invention's effect〕

As is apparent from the above description, according to the present invention, in the scroll compressor, the bypass hole that branches from the oil supply hole penetrating the eccentric portion of the main shaft and opens to the outside of the main shaft, and the bypass hole is provided with the predetermined hydraulic pressure from the oil supply hole. By providing a valve that opens and closes with a valve, even if the rotation speed of the main shaft increases and the amount of oil supplied to each bearing increases due to centrifugal action, the valve opens and more than the required amount of oil is discharged from the bypass hole. It will be returned to the oil sump,
The oil retaining performance of the compressor is improved, the seizure of the bearing does not occur, and a highly reliable scroll compressor can be obtained.

[Brief description of drawings]

1 to 3 show an embodiment of a scroll compressor according to the present invention. FIG. 1 is a vertical sectional view thereof, FIG. 2 is an enlarged vertical sectional view of the vicinity of a lower portion of a spindle, and FIG. FIG. 4 is an enlarged vertical sectional view of the vicinity of the lower portion of the main shaft showing another embodiment of FIG. 2 and FIG. 4 is a vertical sectional view of a conventional scroll compressor. 2 ... Airtight container, 3 ... Fixed scroll, 7 ... Spindle,
7a ... Eccentric hole, 8 ... Upper main bearing, 9 ... Lower main bearing,
14 …… oil sump, 16 …… oil, 17 …… swing scroll, 25…
… Lubrication hole, 25a …… Opening, 27 …… Bypass hole, 28 ……
valve.

Claims (1)

[Claims] Claim: What is claimed is: 1. A vertical main shaft rotatably supported by a main bearing on the housing side, and a main shaft rotatably supported by an eccentric hole in the upper end of the main shaft and revolves as the main shaft rotates to compress a gas between the fixed scroll on the housing side. And an oil supply hole that penetrates an eccentric portion with respect to the shaft center of the main shaft in parallel with the shaft center and communicates the lower oil reservoir with the upper eccentric hole. In a scroll compressor configured to supply oil in the oil sump to each bearing via the oil supply hole and an eccentric hole by force, a bypass hole branched from the oil supply hole and opening to the outside of the main shaft; A scroll compressor provided with a valve that opens and closes a hole with a predetermined hydraulic pressure from the oil supply hole.