JPS5929790A - Scroll type hydraulic machine - Google Patents

Abstract

PURPOSE:To enable a turning scroll to be pressed against a fixed scroll by housing compressively a piston and a spring in a cylinder provided at the rear side of the turning scroll of a casing to press the piston against the turning scroll with a spring force before start. CONSTITUTION:A cylinder 17 communicating to the atmosphere and a back pressure chamber 15 is provided at the rear side of a turning scroll 3 of a casing 1 and houses a piston 18 and a spring 19. Before start, the turning scroll 3 is pressed against a fixed scroll 2 through the piston 18 by the force of the spring 19. Thus, when the back pressure is insufficient, the turning scroll 3 is pressed against the fixed scroll 2 by the force of the spring 19 through the piston 18 so that the anti-wear property of the turning scroll 3 can be improved and the life of a bearing (not shown) in a boss (not shown) of the turning scroll 3 can be extended

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to improvements in scroll type fluid machines.

As shown in FIG. 1, a conventional scroll compressor has a fixed scroll fixed to a casing 1 and having a spiral wrap 2b provided vertically on an end plate 2a, and a spiral wrap 3b provided vertically on an end plate 3a. and an orbiting scroll 3 having both wraps 2b.

3b is inside and the mirror plate 3a is assembled with the phase shifted.
An Oldham ring 4 and a key 5 are provided between the back surface of the orbiting scroll 3 and the casing 1, and a crankshaft 7 connected to a main shaft 6 is rotatably attached to the center of the orbiting scroll 3 via a bearing 8. It is constructed so that it revolves around the Earth without rotating.

The main shaft 6 has a bearing 9 and a sealing device 1 in the casing 1.
The main shaft 6 is rotatably supported via the main shaft 6 and connected to a prime mover (not shown), and a balancer l is provided at both ends of the main shaft 6.
la and llb are respectively attached. Further, a discharge port 13 and a suction port 12 are provided in the center and outer peripheral portions of the end plate 2a of the fixed scroll 2, respectively, and the suction port 12 is provided with a lubricating oil jet hole 14.

In the conventional scroll compressor as described above, when the main shaft 6 is rotated by the prime mover, the orbiting scroll 3 rotates around the center of the fixed scroll 2 while being prevented from rotating. Due to this rotation, the wrap 2 of both scrolls 2 and 3
Since the compression chamber formed between b and 3b is continuously reduced, the gas sucked in through the suction port 12 is compressed and discharged through the discharge port 13.

When compression is performed in this manner, the end plates 2a and 3a of the fixed scroll 2 and the orbiting scroll 3, the Oldham ring 4, and the key 5 are sliding relative to each other. Therefore, in order to make the sliding smooth and seal the wraps 2b and 3b in the radial and axial directions, lubricating oil is injected from the injection hole 14 into the suction port 12, and this lubricating oil is applied to the sliding surface along with the gas. Supplies to moving parts and seal parts.

In addition, in order to obtain a force for pressing the orbiting scroll 3 against the fixed scroll 2, two small holes 16 are provided axially symmetrically at appropriate positions on the end plate 3a of the orbiting scroll, and gas pressure is provided on the back side of the orbiting scroll 3. It is configured to flow into the back pressure chamber 15.

However, with the means for pressing the orbiting scroll 3 against the fixed scroll 2 as described above, during a transitional period such as during startup when sufficient pressure cannot be obtained, the orbiting scroll 3 is not sufficiently pressed against the fixed scroll 2. Because of the rotation, the life of the boss bearing 8 of the orbiting scroll 3 is not shortened, but the wraps 2b, 3b of both scrolls 2, 3 and the end plate 2a.

This has the drawback of causing serious damage to the portion 3a and significantly reducing the wear resistance, resulting in a decrease in the reliability of the entire machine.

The present invention aims to eliminate the above-mentioned drawbacks,
A cylinder that communicates with the atmosphere and the back pressure chamber is provided on the back side of the orbiting scroll in the casing, and a piston and a spring are housed in this cylinder. At startup, the piston is pressed against the orbiting scroll by the force of the spring. , is characterized in that the orbiting scroll is brought into pressure contact with the fixed scroll.

An embodiment of the present invention will be described below with reference to the drawings.

In FIGS. 2 and 3, ■ is a casing, 2 is a fixed scroll consisting of an end plate 2a and a spiral wrap 2b provided vertically on this end plate 2a;
is fixed to the casing 1. - 3 is an orbiting scroll consisting of an end plate 3a and a spiral wrap 3b provided vertically on the end plate 3a, and the wrap 3b is combined with the fixed scroll wrap 2b out of phase. 15
1 is a back pressure chamber formed by the back surface of the orbiting scroll 3 and the skeleton 1; 16 is a small hole provided at an appropriate position on the end plate 3a of the orbiting scroll 3 and axially symmetrical; The space between the υ uppers 2b and 3b and the back pressure chamber 15 are communicated with each other.

17 is a cylinder provided on the back side of the orbiting scroll 3 in the casing 1, and this cylinder 17 is connected to the passage 20.
It communicates with the back pressure chamber 15 and the atmosphere side through a and 20b, respectively. Reference numerals 18 and 19 denote a piston and a piston biasing spring housed in the cylinder 17, and 21 denotes an O-ring provided in the cylinder 17. The piston 18 is provided with a truncated conical recess 18a as shown in FIGS. 4 and 5 on its top surface, and through holes 18b are provided radially in the radial direction, communicating with the recess 18a.

The rest of the structure is the same as the conventional example shown in FIG. 1, so it will be omitted from the drawings and description.

Next, the operation of this embodiment configured as described above will be explained.

Before starting, the orbiting scroll 3 is pressed against the fixed scroll 2 by the force of the spring 19 via the piston 18. The spring 19 is designed to have enough force to maintain the state shown in FIG. is set to . In this way, when the back pressure is not sufficient, the orbiting scroll 3 is pressed against the fixed scroll 2 by the spring 19 via the piston 18, which improves the wear resistance of the orbiting scroll 3 and prevents the bearing of the boss portion of the orbiting scroll 3. (not shown).

Thereafter, when the pressure in the back pressure chamber 15 becomes sufficient, the piston 18 separates from the orbiting scroll 3 as shown in FIG. 3 due to the pressure difference between the back pressure (gas pressure) of the cylinder 17 and atmospheric pressure. The orbiting scroll 3 is pressed against the fixed scroll 2 by back pressure as in the conventional example. At this time, a part of the back pressure is introduced into the recess 18a of the piston 18 through the through hole 18b and presses the piston 18 toward the opposite side of the orbiting scroll, thereby making it easier for the piston 18 to separate from the orbiting scroll 3. .

When the back pressure becomes sufficient, the υ piston 18 is strongly pressed toward the anti-orbiting scroll side by this back pressure, and the biston 18 quickly separates from the orbiting scroll 3. Power loss due to friction with the scroll 3 can be prevented.

In addition, in scroll fluid machines, lubrication is performed using the differential pressure between the discharge pressure and each oil supply part, so the time during which the orbiting scroll 3 is operated apart from the fixed scroll 2 at startup, in other words, If the unstable time at startup is long, the supply of oil to each oil supply section will be delayed, which may cause an accident. However, in this embodiment, as described above, at the time of startup, the orbiting scroll 3 is repelled by the piston 18.
9 is pressed against the fixed scroll 3, each oil supply section can be smoothly lubricated and accidents can be prevented.

As explained above, according to the present invention, at startup, the orbiting scroll is pressed against the fixed scroll by mechanical means,
By pressing the orbiting scroll against the fixed scroll using gas pressure during normal operation, it improves the wear resistance of the orbiting scroll and extends the life of its boss bearing.
The reliability of the entire machine can be improved.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view of a conventional scroll compressor, FIGS. 2 and 3 are cross-sections of essential parts showing the operating state of an embodiment of a scroll-type fluid machine according to the present invention, and FIGS. 4 and 5 are cross-sectional views of a conventional scroll compressor. FIG. 3 is a plan view and a cross-sectional view of the piston of the same embodiment. l...Casing, 2...Fixed scroll, 3 rotating scrolls, 15...Back pressure chamber, 17...Cylinder, 18...Piston, 18a...Concavity, 18b...
・Through hole, 2nd area 4 areas Otaro/Zakari

Claims (1)

[Claims] (1) In a scroll-type fluid machine constructed by combining a fixed scroll and an orbiting scroll with their respective wraps inside, and the orbiting scroll is configured to revolve without rotating, the orbiting scroll rear side of the casing. A cylinder is provided that communicates with the atmosphere side and the back pressure chamber, a piston and a spring are housed in this cylinder, and the piston is pressed against the orbiting scroll by the force of the spring at startup, thereby turning the orbiting scroll into a fixed scroll. A scroll-type fluid machine that is characterized by being pressed in the opposite direction. 2. The scroll-type fluid machine according to claim 1, wherein a recess is provided at the top of the piston, and a through hole communicating with the recess is provided in the radial direction.