JPH025787A - scroll compressor - Google Patents

Abstract

PURPOSE:To supply oil in optimum amount to bearings even though the revolving speed of the spindle has increased, by furnishing a valve opening and closing with a certain specified pressure at a bypass hole, which diverges from the oil supply hole and opens to the outside of the spindle. CONSTITUTION:Near the bottom of an oil supply hole 25 a bypass hole 27 is furnished, which diverges from the oil supply hole 25 and opens to the outside of a spindle 7, and further a valve 28 to open and close this bypass hole 27 is furnished. This valve 28 consists of a valve holder 29, a valve body 30 to fit with the valve seat of the bypass hole 27, and a compression coil spring 31. The spring force of this compression coil spring 31 is set so that the valve body 30 opens when the oil 16 intruding into the bypass hole 27 from the abovementioned oil supply hole 25 attains a specified pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a scroll compressor that compresses refrigerant gas by engaging a pair of spiral side plates with each other and rotating one of the side plates.

[Conventional technology]

This type of scroll compressor is used in refrigerant compressors for refrigeration equipment and air conditioners, etc.
The device disclosed in Japanese Patent No. 6989 is constructed as shown in FIG. 4 in a longitudinal cross-sectional view. That is, a disk-shaped end plate 3a is attached to the upper end of the closed container 2 fixed on the leg 1.
A fixed scroll 3 integrally formed with a spiral scroll side plate 3b protruding from the lower surface thereof is fixed to an upper bearing frame 4 of an example of a closed container with a plurality of bolts 5. A main shaft 7 is rotatably supported by a lower bearing frame 6 integrally connected thereto via an upper main bearing 8 and a lower main bearing 9. Reference numeral 10 denotes a motor stator formed in a cylindrical shape and fixed to the lower bearing frame 6 by a plurality of holes 11, into which the motor stator fixed to the main shaft 7 by press-fitting, burning out, etc. - The rotor 12 is fitted, and by energizing the motor, the main shaft 7 is connected via the motor/rotor I2.
is configured to rotate. 14 is inserted into a hole in a cover 15 that covers the oil reservoir 14 at the bottom of the closed container 2, and the main shaft 7
An oil camp is fixed at the lower end by press-fitting, burning out, etc., and the intake port 13a at the lower end is an oil sump 14.
It opens into the oil 16 stored in the tank.

An eccentric hole 7a is formed at the upper end of the main shaft 7, and the eccentric hole 7a has an axis eccentric to the axis of the main shaft 7, that is, the axis of the upper main bearing 8. An FZ movable scroll shaft 17a indicated by is rotatably supported via a swing bearing 18. 1z moving scroll 17 is
It has a base plate 17b integrally formed with the shaft 17a, and a scroll side plate 17c that is formed in a spiral shape and engages with the scroll side plate 3b of the fixed scroll 3 projects from the upper surface of the base plate 17b. There is. Scroll side plate 3b
A suction port 20 and a discharge port 21 are formed at the outer circumference and the center of the crescent-shaped compression chamber 19 formed between 17c, and these suction port 2O and discharge port 2] are the suction pipe 2a. and a discharge pipe 22 to equipment outside the machine. Reference numeral 23 designates J of the upper main bearing 8: a concentric thrust bearing that extends outward with the inner circumferential circle touching the end; This is an Oldham joint that is provided to restrict the rotation of the oscillating scroll 17.

An oil supply hole 25 with an opening 25a at the lower end opened into the oil cap I3 is provided in the eccentric portion of the main shaft 7 with respect to the axis, and the oil supply hole 25 communicates with the eccentric hole 7a. The inside of the oil reservoir 14 and the rocking bearing 1 are connected through the oil hole 26.
8. The lower main bearing 9 is communicated 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 oscillating scroll 17 restricts its rotation by the Oldham joint 24. The refrigerant gas sucked in from the suction pipe 2a cools the motor rotor 12 and the motor stator lO, and then the scroll side plate 1 of the revolving oscillating scroll 17.
7c and the scroll side of stationary fixed scroll 3 +
It is taken into the compression chamber 19 formed between N3b through the suction port 20 and compressed. The compressed refrigerant gas is discharged from the discharge pipe 22 through the discharge port 21 to the outside of the compressor.

Furthermore, when the main shaft 7 rotates, the oil 16 in the oil reservoir 14 is drained from the suction port 13a of the oil cap 13 due to the action of centrifugal force.
Oil is supplied to the swing bearing 18 and the lower main bearing 9 through the oil supply hole 25, and then from the swing bearing 18 to the upper main bearing 8. The thrust bearing 23 is lubricated in this order. Each of these bearings 18, 9,
The oil 16 that has lubricated the oil 8.23 falls due to gravity and is returned to the oil sump 14.

[Problem to be solved by the invention]

However, in such conventional scroll compressors, the rotation speed is controlled by an inverter, etc., and the main shaft 7 is
When the rotational speed of the main shaft 70 is increased, the angular velocity of the main shaft 70 increases and each bearing 1B due to centrifugal action.

8.9.23 Refueling increased and oil I6 exceeded the required amount
is supplied, and the amount of refrigerant circulated increases so that the airtight container 2
As a result, the oil pressure 6 after lubricating each bearing is sucked into the compression chamber 19 together with the refrigerant gas and discharged to the outside of the compressor before returning to the oil reservoir 14.
There were problems such as a decrease in the amount of oil retained in the compressor and the sliding parts seizing up.

The present invention was made in order to solve these problems, and it is an object of the present invention to provide a scroll compressor that can supply an optimal amount of oil to each bearing even when the rotational speed of the main shaft increases. The purpose is

[Means to solve the problem]

In order to achieve such an object, the present invention provides a bypass hole that branches off from an oil supply hole passing through the eccentric portion of the main shaft and opens to the outside of the main shaft, and a valve that opens and closes this bypass hole using a predetermined hydraulic pressure from the oil supply hole. and has been established.

[For production]

When the main shaft rotates, centrifugal force causes oil in the oil reservoir to be supplied to each bearing through the oil supply hole. When the rotational speed of the main shaft increases and centrifugal force increases, the oil pressure that exceeds a predetermined pressure opens the valve, and excess oil is discharged from the bypass hole and returned to the oil reservoir.

(Embodiment) FIGS. 1 and 2 show an embodiment of a scroll compressor according to the present invention, in which FIG. 1 is a longitudinal sectional view thereof, and FIG. 2 is an enlarged longitudinal sectional view of the vicinity of the lower part of the main shaft.

In the figure, members having the same configuration as those of the conventional scroll compressor shown in FIG. 4 are designated by the same reference numerals, and a detailed explanation thereof will be omitted, and a brief explanation will be given below. A vertical main shaft 7 is attached to the upper and lower main bearings 8°9 fixed to the side of the closed container 2 serving as a casing.
is pivotally supported, and an eccentric hole 7a formed at the upper end of the main shaft 7 has an airtight container 24 that revolves with the rotation of the main shaft 7.
! A shaft 17a of an oscillating scroll I7 that compresses refrigerant gas and the like between the fixed scroll 3 of an oscillating scroll I4 is supported via an oscillating bearing 18. 23 is a thrust bearing that receives the load in the axial direction of the orbiting scroll 17.

An oil supply hole 25 with an opening 25a at the lower end opened into the oil cap 13 is provided in the eccentric part of the main shaft 7 with respect to the axis, parallel to the axis and penetrating in the axial direction. It is opened at 7a. Further, the oil supply hole 25 is communicated with the lower main bearing 9 through an oil passage hole 26 .

In this device, a bypass hole 27 is located near the lower end of the oil supply hole 25 and branches from the oil supply hole 25 to open to the outside of the main shaft 7.
is provided in the radial direction on the opposite axis side of the oil supply hole 25,
Further, a valve 28 for opening and closing the bypass hole 27 is provided. The valve 28 includes a valve holder 29 formed in a hollow annular shape so as to maintain rotational balance and is positioned and fixed in the corresponding part of the bypass hole 27 of the main shaft 7 by press-fitting, sintering, etc. 27, and a compression coil spring 31 that biases the valve body 30 in the closing direction of the bypass hole 27. The lower surface of the valve holder 29 has a discharge hole 32 is opened. The spring force of the compression coil spring 31 is then applied to the oil supply hole 2.
The valve element 30 is set to open when the oil 16 entering the bypass hole 27 from the oil valve 5 reaches a predetermined pressure.

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, the oscillating scroll 17 eccentrically revolves and is fixed while being restricted from rotating. The refrigerant gas is compressed between the scroll 3 and the scroll 3.

When the main shaft 7 rotates, oil in the oil reservoir I4 is supplied to the TF dynamic bearing I8 and the main bearing 9 through the suction port 13a of the oil cap 13 and the oil supply hole 25 due to the action of centrifugal force. Further, from the swing bearing 18 to the upper main bearing 8. The thrust bearing 23 is lubricated in this order. Each of these bearings 18,9
．． The oil 16 that has lubricated the oil 8.23 falls due to gravity and is returned to the oil sump 14.

The rotation speed is controlled by an inverter, etc., and as the rotation speed of the main shaft 7 increases, each bearing lB, 8, 9.2 is
The amount of oil supplied to bearings 1B and 3 increases, but at the same time the centrifugal force also increases, and the valve body 30 of the valve 28 moves in the opening direction against the elastic force of the compression coil spring 31. 8,
A part of the oil 16 supplied to 9.23 is returned to the oil sump 14 via the bypass hole 27 and the discharge hole 32. in this case,
The rotational speed of the main shaft 7 and the opening degree of the valve 28 when the valve 28 starts to open 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,
The amount of oil supplied to bearings 18, 8 and 23 does not increase significantly, and due to the way the elastic force of the compression coil spring 31 is set, only a certain amount of oil is supplied to each bearing 18, 8 at a certain rotation speed or higher.
, 9.23, the amount of oil 1 that is sucked into the compression chamber 19 with the suction gas 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 cross-sectional view of the vicinity of the lower part of the main shaft showing another embodiment of the present invention corresponding to FIG. It is biased in the closing direction by a fixed leaf spring 33. The other configurations and effects are the same as in the previous embodiment.

〔Effect of the invention〕

As is clear from the above description, in a scroll compressor according to the present invention, a bypass hole that branches off from an oil supply hole penetrating the eccentric portion of the main shaft and opens outside the main shaft, and a predetermined hydraulic pressure from the oil supply hole are connected to the bypass hole. By installing a valve that opens and closes at the same time, even if the rotational speed of the main shaft increases and the amount of oil supplied to each bearing due to centrifugal action increases, the valve will open and more oil than necessary will be discharged from the bypass hole. Because it is returned to the oil sump,
This has the effect of improving the oil retention performance of the compressor, preventing seizure of bearings, and providing a highly reliable scroll compressor.

[Brief explanation of the drawing]

1 to 3 show an embodiment of a scroll compressor according to the present invention, FIG. 1 is a longitudinal sectional view thereof, FIG. 2 is an enlarged longitudinal sectional view near the bottom of the main shaft, and FIG. 3 is an embodiment of the present invention. Another embodiment of the present invention is shown in an enlarged vertical cross-sectional view near the lower part of the main shaft corresponding to FIG. 2, and FIG. 4 is a vertical cross-sectional view of a conventional scroll compressor.

Claims (1)

[Claims] Oscillation that compresses gas between a vertical main wheel that is supported by a main bearing on the housing side and a fixed scroll on the housing side that is supported on an eccentric hole at the upper end of this main shaft and revolves with the rotation of the main shaft. The oil supply hole is provided with a scroll and an oil supply hole that penetrates an eccentric part of the main shaft in parallel with the shaft center and communicates a lower oil reservoir with the upper eccentric hole, and the oil is supplied by centrifugal force caused by rotation of the main shaft. In a scroll compressor configured to supply oil in a reservoir to each bearing through the oil supply hole and the eccentric hole, a bypass hole that branches from the oil supply hole and opens to the outside of the main shaft, and a bypass hole that is connected to the oil supply hole are provided. A scroll compressor characterized by being provided with a valve that opens and closes with a predetermined oil pressure from a hole.