JPS6069280A - scroll compressor - Google Patents

Abstract

PURPOSE:To provide a rotary scroll with proper axial force by a method wherein a back pressure chamber, formed by the rotary scroll and a frame, is communicated with an operating chamber and an oil chamber is formed at the engaging part of the rotary scroll and a crank shaft. CONSTITUTION:The crank shaft 8 is formed with an oil introducing hole 11, inclined with respect to the axial center line thereof, and one end of the oil introducing hole 11 is opened at the oil chamber 10 while the other end thereof is opened on the axial center line of the shaft at the lower end of the crank shaft 8. The back pressure chamber 14 at the opposite lapping side of the mirror plate 4 of the rotary scroll 6 is constituted of the fixed scroll 3, the frame 9, the crank shaft 8 and the rotary scroll 6. The back pressure chamber 14 is communicated with a compression chamber 16 through a small hole 15 and pushes the rotary scroll 6 into the axial direction with a proper force together with the oil pressure of the oil chamber 10.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a scroll compressor for refrigeration air conditioners (room air conditioners, package air conditioners, chiller units, freezer/refrigerator units, refrigerators, etc.), helium liquefaction, and the like.

[Background of the invention]

Two (2) scrolls each having a spiral wrap standing upright on an end plate are interlocked with each other, and one scroll is rotated relative to the other scroll without apparently rotating on its own axis. A scroll compressor in which a two-moon-shaped compressor formed between scrolls is moved from the suction port toward the discharge port (the center of the end plate) and simultaneously reduces the volume is disclosed in Japanese Patent Application Laid-Open No. 53-35840. There is.

In such a scroll compressor, both end plates receive a force (separation force) in the direction of separating them from each other due to the gas pressure in the compression chamber between both scrolls, so in order to prevent both end plates from separating, It is necessary to apply an axial force to the scroll that is greater than the force generated by the gas pressure. on the other hand,
The magnitude of the separation force varies depending on changes in suction pressure and discharge pressure, and the degree of influence is smaller on discharge pressure than on suction pressure.

As a means of applying axial force to the scroll, it is known to apply gas pressure during the compression process to the back surface of the orbiting scroll (3), as shown in Japanese Patent Application Laid-Open No. 119412/1983. .

However, in this method, the axial force applied to the orbiting scroll is generated by the gas pressure in the compression chamber, so the magnitude of the axial force follows only changes in suction pressure, and does not depend on changes in discharge pressure. Doesn't really follow. Therefore, due to changes in discharge pressure, the relationship between the separation force and the axial force acting on the orbiting scroll breaks down (exceeds the permissible range).
It is not possible to constantly apply an appropriate axial force to the orbiting scroll.

[Purpose of the invention]

An object of the present invention is to provide a scroll compressor that can always apply an appropriate axial force to an orbiting scroll regardless of changes in suction pressure and discharge pressure.

[Summary of the invention]

The feature of this invention is that the orbiting scroll and the frame guide the gas pressure in the working chamber formed by both the orbiting and fixed scrolls to the back pressure chamber formed on the back lap side of the orbiting scroll. The oil guide hole formed in the crankshaft is opened into the oil chamber formed by the engagement of the orbiting scroll with the crank pin of the crankshaft, and the oil from the oil guide hole is supplied to the oil chamber to reduce the back pressure. The axial pressing consists in applying a force to the orbiting scroll both by the gas pressure in the chamber and by the hydraulic pressure in the oil chamber.

[Embodiments of the invention]

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

The fixed scroll 3 has an end plate 1 and a spiral wrap 2 formed upright thereon, and the orbiting scroll 6 has a disk-shaped end plate 4 and a spiral wrap 2 formed upright thereon. Both wraps 2 and 5 are an involute curve or a curve approximated thereto. The fixed scroll 3 and the orbiting scroll 6 each have a lap 2,
5 are interlocking. A frame 9 is coupled to the fixed scroll 3, and this frame 9 is connected to the orbiting scroll 6.
is surrounding. An Oldham ring key (5)-7 for preventing rotation of the orbiting scroll 6 is arranged between the frame 9 and the opposite side of the end plate 4 of the orbiting scroll 6.

A crankshaft 8 is rotatably supported at the center of the frame 9 via a bearing 9a. This crankshaft 8 is equipped with a crank pin 8a on its head, and the crank pin 8a is formed at a position eccentric from the center of the crankshaft 8 by a distance corresponding to the turning radius, and has a diameter comparable to that of the crankshaft 8. .

A boss portion 4 is provided on the opposite side of the end plate 4 of the orbiting scroll 6.
The crank pin 8a is inserted into the boss portion 4b via a bearing 4a, and an oil chamber 10 is formed between the upper end surface Bal of the crank pin 8a and the end plate 4.

The crankshaft 8 is formed with an oil guide hole 11 that is inclined with respect to the shaft center line. One end of the oil guide hole 11 opens into the oil chamber 10, and the other end is located at the lower end of the crankshaft 8 and the shaft. It opens on the center line.

Further, in the middle of the oil guide hole 11, an oil supply hole 12 that supplies oil to the bearing 9a and an oil supply hole 1 that supplies oil to the bearing 4a are provided.
3 have been contacted.

(6) Fixed scroll 3. Frame 9. Crankshaft8.
and the orbiting scroll 6, the orbiting scroll 6
A back pressure chamber 14 is formed on the opposite side of the mirror plate 4. This back pressure chamber 14 is communicated with a compression chamber 16 through a small hole 15 formed in the end plate 4.

On the crankshaft 8 (at the lower part of the bearing 9a),
Motor rotor 17 is coupled, motor stator 18 is
It is supported by chamber 19. Fixed scroll 3. Orbiting scroll 6, crankshaft 8. Frame 9. Oldham ring key 7, and motor (motor rotor 1)
7. The stator 18 ) is housed inside the chamber 19 .

A discharge port 21 formed in the fixed scroll 3 opens in a discharge chamber 20 formed by the chamber 19 and the fixed scroll 3, and a motor chamber 22 formed by the frame 9 and the chamber 19 and a discharge port 21 formed in the fixed scroll 3 are opened. The chamber 20 is communicated with the fixed scroll 3 and the frame 9 by holes 23, 24 and a pipe 25 formed in series with each other.

(7) Reference numeral 26 is a balance weight coupled to the crankshaft 8, 27 is a lift cup coupled to the lower end of the crankshaft 8, 28 is a compressed gas discharge pipe, and 29 is a suction pipe. , numeral 30 is an inlet.

Next, the operation will be explained.

Power is supplied to the coil of the stator 18 via a hermetic terminal (not shown), and the motor rotor 17 rotates.

Due to the rotation of the motor rotor 17, the crankshaft 8
rotates, and the orbiting scroll 6, which is engaged with the crank pin 8a, orbits at a radius substantially equal to the eccentricity of the crank pin 8a. Since the orbiting scroll 6 is prevented from rotating on its own axis, that is, rotating around the crank pin 8a, by the Oldham ring key 7, it orbits without apparently rotating on its axis. Due to the orbiting motion of the orbiting scroll 6, the compression chamber 16 moves from the outer periphery of the end plates 1 and 4 toward the center, and at the same time reduces the volume, whereby gas is sucked from the suction port 30, ) It is compressed and discharged from the discharge port 21 into the discharge chamber 20 . In the discharge chamber 20, oil contained in the discharged gas is separated,
Oil flows into the motor chamber 22 through the holes 23, 24, and gas flows through the holes 23, 24 and the pipe 25, respectively.

The compressed gas entering the motor chamber 22 is transferred to the motor stator 18.
It passes around the rotor 17 and from the discharge pipe 28 to the condenser (
(not shown). When the compressed gas passes through the motor chamber 22, it removes heat from the motor (the compressed gas is quite hot, but the coils of the stator 17 are even hotter) and cools the motor.

On the other hand, the oil that has entered the motor chamber 22 is collected at the bottom of the chamber 19, and this oil is stored in the frying oil cup 27. The oil is supplied to the bearings 9a, 4a through the oil guide hole 11 and the oil supply hole 12.13.

Further, oil from the oil guide hole 11 is also supplied to the oil chamber 10.

Next, the axial pressing force applied to the orbiting scroll 3 will be explained. Since the discharge chamber 20 communicates with the discharge port 21 and the motor chamber 22 communicates with the discharge chamber 20, the oil at the bottom of the motor chamber 22 has a pressure equal to the discharge pressure (9). Since the oil chamber 10 communicates with the motor chamber 22 via the oil guide hole 11, there is a hydraulic pressure approximately equal to the discharge pressure in the oil chamber 10. Since the gas pressure in the compression process is led to the back pressure chamber 14, gas pressure exists in the back pressure chamber 14, and the orbiting scroll 6 handles the oil pressure in the oil chamber 10 and the gas pressure in the back pressure chamber 14. fixed scroll by both 3
An axial force (axial pressing is a force) is applied in the direction of .

On the other hand, if the suction pressure changes, for example, becomes lower, the pressure in all the compression chambers 16 will decrease accordingly, and the separation force acting between both scrolls 3 and 6 will become smaller. At this time, the influence of the decrease in suction pressure on the discharge pressure is negligible.

Further, if the discharge pressure changes, for example increases, the pressure only in the compression chamber 16a communicating with the discharge port increases accordingly, and the separation force acting between both scrolls 3 and 6 becomes slightly larger. At this time, each compression chamber 16 due to the increase in discharge pressure
The influence on the pressure (excluding the compression chamber 16a) is negligible.

Therefore, when the suction pressure changes, the axial pressing force applied to the orbiting scroll 6 by the gas pressure changes, following the change in the separation force acting between the scrolls 3 and 6 due to the change in suction pressure. The separation force acting on the orbiting scrolls 3 and 6 maintains a constant relationship between the forces (the axial pressing force is larger than the separation force by an appropriate amount), and when the discharge pressure changes, the discharge Following the change in the separation force acting between both scrolls 3 and 6 due to a change in pressure, the axial pressing force applied to the orbiting scroll 6 by the hydraulic pressure changes, and the separation force acting on the orbiting scroll and the axial direction change. Pressure maintains a constant relationship (same as above) with force.

According to the embodiment described above, the axial pressing against the orbiting scroll not only maintains the force properly at all times regardless of fluctuations in suction and discharge pressures, but also simultaneously supplies lubricating oil to each bearing and slide. It has an effect that can be done.

(Effects of the Invention) (11) As described above, according to the present invention, force can always be applied to the orbiting scroll by proper axial pressing regardless of changes in suction pressure and discharge pressure.

[Brief explanation of the drawing]

The figure is a longitudinal sectional view of an embodiment of the present invention. 1.4... End plate, 2,5... Wrap, 3... Fixed scroll, 6... Orbiting scroll, 7... Oldham ring key, 8... Crankshaft, 9...
flame. 10... Oil chamber, 11... Oil pumping hole, 14 River back pressure chamber, 1
5...Small hole, 16...Compression chamber. Agent Patent attorney Akio Takahashi (12)

Claims (1)

[Claims] 1. A fixed scroll having an end plate and a spiral wrap, and an orbiting scroll having an end plate and a spiral wrap, the wraps of which are engaged with each other, and a crankshaft supported by a frame via bearings. The orbiting scroll engages with the fixed scroll, and the orbiting scroll rotates without apparently rotating on its own axis relative to the fixed scroll, thereby causing a space between the two scrolls to move between the suction port and the discharge port along with the orbiting motion. and a plurality of working chambers whose volumes change are formed, the crankshaft having a passage connecting the front pressure chamber and the back pressure chamber formed by the orbiting scroll and the frame with the working chamber; 1. A scroll compressor having an oil chamber formed by engagement between an orbiting scroll and a crankshaft at the head thereof, and an oil guide hole opening into the oil chamber in the crankshaft. (1) 2. The scroll compressor according to claim 1, wherein the passage connecting the back pressure chamber and the working chamber is a small hole formed in the end plate of the orbiting scroll. 3. The scroll compressor according to claim 1, wherein the oil guide hole is inclined with respect to the axial center line of the crankshaft. 4. In claim 1, a fixed scroll;
A scroll compressor in which the orbiting scroll, frame, crankshaft, motor rotor, stator, and Oldham ring key are housed in a sealed chamber.