JPH05149269A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To eliminate necessity for decreasing the bore of a delivery port so as to reduce a compression loss by arranging a delivery valve, actuated to open/close by a pressure difference between a compression mechanism and a high pressure side thus to guide delivery gas to the outside from the compression mechanism, in a discharge cover. CONSTITUTION:A valve seat 17a of a delivery valve 17 is arranged in an opening surface of a high pressure chamber 42, formed between a back surface of a fixed scroll 1 and a discharge cover 31 and further to appear in a ventilating port 31a, to mount a valve unit 17b to this valve seat. The valve unit 17b is covered with a retainer 17c, and an opening, not shown, connected to a high pressure side 44 is drilled in this retainer. The valve unit 17b is vertically moved by a pressure difference between a compression mechanism C or the compression chamber 42 and the high pressure side 44 to actuate the delivery valve 17 opened/closed. Thus by arranging the delivery valve 17 in the discharge cover 31, even in the case that an area of the high pressure chamber 42 arranged with the delivery valve 17 is decreased in the past by coping with a back pressure load, necessity for decreasing the bore of a delivery port 13 in accordance with a size of the delivery valve 17 is eliminated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll type fluid machine used as a compressor or an expander.

[0002]

2. Description of the Related Art FIG. 2 is a vertical sectional view of an example of a conventional scroll type compressor. The interior of the closed housing 8 is partitioned by a discharge cover 31 into a high pressure side 44 and a low pressure side 45. Inside the low-pressure side 45, a scroll type compression mechanism C is arranged at an upper part thereof and an electric motor M is arranged at a lower part thereof, which are interlockingly connected to each other via a rotary shaft 5. The electric motor M includes a rotor Ma and a stator Mb, the rotor Ma is fixed to the rotating shaft 5, and the stator Mb is fixed by being press-fitted into the hermetically sealed housing 8.

The scroll compression mechanism C comprises a fixed scroll 1 and an orbiting scroll 2. The fixed scroll 1 includes an end plate 11 and a spiral wrap 12 provided upright on the inner surface of the end plate 11. The discharge port 1 is provided at the center of the end plate 11.
3 is provided. The orbiting scroll 2 is provided with an end plate 21 and a spiral wrap 22 provided upright on the inner surface of the orbiting scroll 2, and a drive bush 54 is rotated through a orbiting bearing 73 in a boss 23 provided upright on the outer surface of the end plate 21. The eccentric pin 5 which is freely inserted and protrudes from the upper end of the rotary shaft 5 into a slide hole 55 formed in the drive bush 54.
3 is slidably fitted.

The fixed scroll 1 and the orbiting scroll 2 are eccentric with respect to each other by a predetermined distance, and are meshed with each other at an angle of 180 degrees to form a plurality of closed spaces 24. The orbiting scroll 2 is a closed housing 8
A slidably supported on a frame 6 fixed inside and allowing rotation of the swivel scroll 2 between the swivel scroll 2 and the frame 6 but preventing the rotation thereof. The mechanism 3 is provided.

The fixed scroll 1 is floatably mounted on a frame 6 via a support spring 32 arranged on the outer periphery of the end plate 11.
Supported by. On the back surface of the end plate 11 of the fixed scroll 1, a concentric cylindrical flange 15 centered on the center thereof,
16 is protruded upward, and is enclosed by the cylindrical flanges 38 and 39 protruded downward on the lower surface of the discharge cover 31 between these in a sealed and slidable manner. An intermediate pressure chamber 40 is formed, and the intermediate pressure chamber 40 communicates with the sealed space 24, which is in the middle of compressing gas, through a pressure guiding hole 41 formed in the end plate 11. A high pressure chamber 42 is formed on the inner peripheral side of the intermediate pressure chamber 40, and a low pressure chamber 43 is formed on the outer peripheral side. The upper end of the rotary shaft 5 is supported by an upper bearing 71 provided on the frame 6, and the lower end thereof is supported by a lower bearing 72.

By driving the electric motor M, the orbiting scroll 2 is driven by a revolving orbiting mechanism composed of a rotating shaft 5, an eccentric pin 53, a drive bush 54, a boss 23, etc., and the orbiting scroll 2 is rotated by a rotation preventing mechanism 3. While being blocked, it makes a revolution revolution motion on a circular orbit having a radius of revolution revolution. Then, the gas becomes the suction pipe 8
2 into the low pressure chamber 45, and is sucked into the closed space 24 via a path (not shown). And the orbiting scroll 2
As the volume of the closed space 24 decreases due to the orbiting motion of the
From the high pressure chamber 42 to the high pressure side 44
Then, it is discharged from there through the discharge pipe 83.
At this time, the fixed scroll 1 is pressed against the orbiting scroll 2 by the back pressure load due to the gas pressure in the high pressure chamber 42 and the intermediate pressure chamber 40, and gas leakage from the sealed space 24 is suppressed. When the liquid is sucked into the closed space 24, the fixed scroll 1 floats and the liquid is released to prevent the scroll type compression mechanism C from being damaged.

At the same time, the lubricating oil stored in the oil sump 81 at the bottom of the closed housing 8 is sucked up from the lower end of the rotary shaft 5 by utilizing centrifugal force, and passes through the oil supply hole 52 formed in the rotary shaft 5. Eccentric pin 53, upper bearing 7
1, after lubricating the sliding portions such as the rotation preventing mechanism 3 and the slewing bearing 73, the oil returns to the oil sump 81 through a path (not shown) and is stored there.

On the other hand, when the operation of the compressor is stopped, the discharge valve 17 is closed to prevent the gas from flowing backward from the high pressure side 44 into the compression mechanism C, thereby preventing the reverse rotation of the rotary shaft 5. This prevents the sliding part from running out of oil.

[0009]

In the scroll type compressor of this type, the discharge valve 17 which opens and closes based on the pressure difference between the compression mechanism C and the high pressure side 44 is provided on the rear surface of the fixed scroll 1 facing the high pressure chamber 42. It was installed.

However, in order to apply a stable back pressure load with little fluctuation to the fixed scroll 1, it is desirable to make the area of the high pressure chamber 42 small, especially when the displacement amount of the compression mechanism C is small. Therefore, there is a case where a sufficient space for installing the discharge valve 17 cannot be secured. On the other hand, the discharge valve 17 of a small size
However, since the diameter of the discharge port 13 must be reduced according to the size of the discharge valve 17, the discharge pressure loss increases, and there is a problem that the capacity of the compressor deteriorates.

An object of the present invention is to provide a scroll type fluid machine in which the diameter of the discharge port does not need to be reduced and the pressure loss does not increase even when the area of the high pressure chamber is reduced.

[0012]

DISCLOSURE OF THE INVENTION The present invention is to solve the above-mentioned problems by providing a discharge cover for partitioning the inside of a hermetically sealed housing into a high pressure side and a low pressure side, and providing a fixed scroll and an orbiting scroll on the low pressure side. A scroll-type fluid machine that accommodates a compression mechanism provided and presses the fixed scroll against the orbiting scroll by a fluid pressure introduced into a high-pressure chamber formed between the back surface and the discharge cover, A scroll type fluid machine characterized in that a discharge valve for guiding the gas discharged from the compression mechanism to the outside by opening and closing based on the pressure difference between the compression mechanism and the high pressure side is installed in the discharge cover. It is about.

[0013]

In the present invention, since the discharge valve is installed on the discharge cover, it is not necessary to reduce the diameter of the discharge port even when the area of the high pressure chamber is small and the space for installing the discharge valve is insufficient. The discharge pressure loss will not increase.

[0014]

1 is a vertical sectional view of a first embodiment of the present invention. In the figure, 31a is a discharge cover 3 for partitioning the inside of the closed housing 8 into a high pressure side 44 and a low pressure side 45.
Reference numeral 1 denotes a ventilation port provided to serve as the gas flow path, and 17 denotes a discharge valve provided at the ventilation port 31a. 17a, 1
Reference numerals 7b, 17c, and 17c are components of the discharge valve 17, 17a is a valve seat, 17b is a valve body, 17c is a retainer, and 17d is a retaining ring. The parts other than the above are the same as those of the conventional technique, and thus the description thereof will be omitted.

In this embodiment, the ventilation port 3 is formed between the back surface of the fixed scroll 1 and the discharge cover 31.
A ring-shaped valve seat 17a is arranged on the opening surface of the high-pressure chamber 42 facing 1a, and the disc-shaped valve body 1 is mounted on the valve seat 17a.
7b is mounted. A retainer 17c is attached so as to cover the valve body 17b with a gap. The retainer 17c is provided with an opening (not shown) communicating with the high pressure side 44, and the retainer is fixed in place by a retaining ring. There is. Therefore, the discharge valve 17 is opened / closed by vertically moving the valve body 17b based on the pressure difference between the compression mechanism C or the high-pressure chamber 42 and the high-pressure side 44, and is discharged from the compression mechanism C during operation of the compressor. The discharged gas pushes up the valve body 17b from the high pressure chamber 42 through the discharge port 13 and enters the high pressure side 44, from which it is discharged to the outside through the discharge pipe 83. On the other hand, immediately after the operation of the compressor is stopped, the pressure on the high pressure side 44 communicating with the outside of the compressor is higher than the pressure of the compression mechanism C. In this case, the pressure difference between the two causes Since the discharge valve 17 is closed, the gas does not flow backward from the high pressure side 44 into the compressor C, and the sliding portion is prevented from running out of oil due to the reverse rotation of the rotary shaft 5.

It should be noted that depending on the area of the high pressure chamber 42, the ventilation port 3
The discharge valve 17 can be freely installed in the discharge cover 31 by appropriately setting the width of 1a. Further, the discharge valve 17 may be one that opens and closes based on the pressure difference, and for example, a so-called reever valve shown in the conventional example of FIG. 2 can be used.

Thus, by installing the discharge valve 17 in the discharge cover 31, it is not necessary to reduce the diameter of the discharge port 13 even when the area of the high pressure chamber 42 is small and the space for installing the discharge valve 17 therein is not sufficient. Therefore, the discharge pressure loss is not increased.

[0018]

In the scroll type fluid machine of the present invention, a discharge cover for partitioning the closed housing into a high pressure side and a low pressure side is provided, and a compression mechanism having a fixed scroll and an orbiting scroll is housed on the low pressure side. In a scroll type fluid machine in which the fixed scroll is pressed against the orbiting scroll by a fluid pressure introduced into a high pressure chamber formed between the back surface and the discharge cover, the fixed scroll is discharged from the compression mechanism. Since a discharge valve for guiding the gas to the outside by opening and closing based on the pressure difference between the compression mechanism and the high pressure side is installed in the discharge cover, even if the area of the high pressure chamber is reduced, the discharge port Scroll type fluid machine with improved capacity and less discharge pressure loss, eliminating the need to reduce the bore diameter It is possible to provide a.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view of an essential part of an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a conventional scroll compressor.

[Explanation of symbols]

 C compression mechanism 1 fixed scroll 2 orbiting scroll 8 hermetic housing 17 discharge valve 17a valve seat 17b valve body 17c retainer 17d retaining ring 31 discharge cover 31a vent hole 42 high pressure chamber 44 high pressure side 45 low pressure side

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Toshiyuki Shikauchi 3-1, Asahimachi, Nishibiwajima-cho, Nishikasugai-gun, Aichi Prefecture Mitsubishi Heavy Industries, Ltd. Air Conditioning Factory

Claims (1)

[Claims] 1. A discharge cover for partitioning a sealed housing into a high pressure side and a low pressure side is provided, and a compression mechanism having a fixed scroll and an orbiting scroll is housed on the low pressure side. In a scroll type fluid machine configured to be pressed against the orbiting scroll by a fluid pressure introduced into a high pressure chamber formed between the compression mechanism and the high pressure side, the gas discharged from the compression mechanism The discharge valve that is opened and closed based on the pressure difference
A scroll-type fluid machine characterized by being installed on the discharge cover.