JPH0571798B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a scroll compressor used in a refrigeration cycle or the like, and particularly relates to a thrust support method for a scroll that performs an orbiting motion and to prevention of inclination.

Conventional configuration and its problems The conventional configuration will be explained with reference to FIGS. 1 and 2. 1
2 is a sealed casing, 2 is an electric motor section, and a mechanical section main body 7 consisting of a block 3, a fixed scroll 4, an orbiting scroll 5, and an automatic prevention mechanism 6 is fixed to the upper part thereof. The fixed scroll 4 is
It consists of an end plate 4a and a lap 4b formed of an involute or a curve similar to an involute standing upright on the end plate 4a and having a uniform thickness and height, and is fixed to the block 3 by the end plate 4a. Moreover, the orbiting scroll 5 has an end plate 5a and an end plate 5.
It is composed of a lap 5b that stands upright at the top of the fixed scroll 4 and has the same curve as the lap 4b of the fixed scroll 4.
a indicates the end plate 4a of the fixed scroll 4 and the block 3.
They are sandwiched and supported with a slight clearance between them, and are restrained by an automatic prevention mechanism 6.

The fixed scroll 4 and the orbiting scroll 5 are aligned with the end ends 4b', 5b' of each wrap 4b, 5 shifted by a certain angle.

8 is a discharge hole, 9 is a suction hole, and the discharge hole 8 is provided in the center of the involute of the fixed scroll 4. Further, the suction hole 9 is provided to penetrate the outer edge of the end plate 4a of the fixed scroll 4. 10 is a projection provided on the opposite side of the orbiting scroll 5 from the wrap 5b, and is concentric with the center of the involute of the wrap 5b. 11 is block 3
The electric motor section 2 and the orbiting scroll 5 are connected by housing the protrusion 10 of the orbiting scroll 5 in a boss section 11a provided at the end of the mechanical section main body 7 side and eccentric from the shaft center. ing. 12 is a back pressure chamber formed on the back surface of the orbiting scroll 5, and is sealed from the wrap 5b side of the orbiting scroll 5 by end plates 5a and 4a.
It communicates with a compression space 13 formed by the fixed scroll 5 and the orbiting scroll 4 via communication holes 14a and 14b. 15 is a suction pipe, and 16 is a discharge pipe.

Next, the compression mechanism of the scroll compressor will be explained. The rotational movement of the shaft 11 accompanying the rotation of the electric motor section 2 is transmitted to the orbiting scroll 5 via the boss section 11a and the projection section 10, but the automatic prevention mechanism 6
Due to this action, the orbiting scroll 5 rotates around the center of the involute of the fixed scroll 4 without rotating. At this time, the end 5b' of the wrap 5b of the orbiting scroll 5 is the wrap 4b of the fixed scroll 4, and the end 4b' of the wrap 4b of the fixed scroll 4 is the end 5b' of the wrap 5b of the fixed scroll 4.
Inhalation is completed when the two contact points of the wraps 4 and 5b approach the center of the involute as the orbiting scroll 5 revolves, and the pressure in the compression space 13 increases.

Due to the compression mechanism of this scroll compressor, the refrigerant sucked into the suction pipe 15 through the suction hole 9 is once discharged into the sealed casing 1 through the compressed discharge hole 8 and then through the discharge pipe 16. Discharged to a cooling system (not shown). At this time, as the pressure in the compression space 13 increases, a thrust force is generated between the fixed scroll 4 and the orbiting scroll 5 that tends to separate them in the axial direction. If the fixed and orbiting scrolls 4 and 5 are separated by this thrust force, the seal between the axial end faces of the laps 4b and 5b will be incomplete, increasing leakage and reducing efficiency. Back pressure chamber 12
In addition, an intermediate pressure that has not reached the discharge pressure during the compression stroke is introduced through the communication holes 14a and 14b to apply a pressing force to the orbiting scroll 5 that is greater than the thrust force caused by the compressed gas. However, in the actual compression stroke, the thrust force due to the compressed gas is
The orbiting scroll 5 is not point symmetrical with respect to the involute center, and therefore, in the conventional method of pressing the back surface of the orbiting scroll 5 with equal distribution, the orbiting scroll 5 is tilted, and a part of the lap 5b of the orbiting scroll 5 is However, there was a problem that the compressed gas leaked away from the end plate 4a of the fixed scroll 4 and the efficiency decreased.

In addition to the conventional example described above, there is a method of introducing high-pressure gas to the back of the orbiting scroll 5 to maintain the thrust force due to compression.At high pressures, there is no problem in terms of sealing, but on the other hand, the pressing force is too large and mechanical loss occurs. There are problems such as an increase in energy consumption and a decrease in efficiency. In addition, in a method in which low pressure is introduced to the back surface of the orbiting scroll 5 and a compression spring made of a coiled spring is arranged, the coiled spring presses the rotating member against the fixed member, and the coiled spring slides. In order to prevent bending in the direction, the structure is complicated in that it is necessary to support the coil in the spring.

OBJECT OF THE INVENTION The present invention solves the drawbacks of the above-mentioned conventional examples.
The purpose is to prevent tilting of the orbiting scroll due to uneven thrust force of compressed gas.

Structure of the Invention The present invention introduces low pressure to the back surface of the orbiting scroll, and arranges a cylindrical spring on the rear surface to maintain the thrust force of the compressed gas, thereby tilting the orbiting scroll due to the uneven thrust force of the compressed gas. This is to prevent

DESCRIPTION OF EMBODIMENTS An embodiment of the present invention will be described below as shown in FIGS. 3, 4, and 5.
This will be explained using figures.

Incidentally, the same parts as in the conventional example are given the same reference numerals, and the description thereof will be omitted.

Numerals 17 and 18 are a fixed scroll and an orbiting scroll, respectively, and have laps 17b and 18b of the same shape as the conventional scrolls, which stand upright on end plates 17a and 18a. Further, the end plate 18a of the orbiting scroll 18 is
It does not come into contact with the end plate 17a of the fixed scroll 17. Reference numeral 19 designates a plurality of cylindrical springs provided between the back surface of the orbiting scroll 18 and the block 3, which are housed in the groove 3a of the block 3, and are also inserted into the laps 17b and 18b and the end plates 18a and 17a during assembly.
A preload is applied to ensure reliable contact with the Further, 20 is a back pressure chamber of the orbiting scroll 18, which communicates with the suction hole 9.

In the above configuration, the refrigerant gas received through the suction hole 9 is compressed in the compression space 13 as in the conventional case, but a portion of the suction gas enters the back pressure chamber 20. Therefore, the thrust force acting on the orbiting scroll 18 due to compression is partially supported by the uniformly distributed load due to the low pressure gas of the suction gas, and is mostly supported by the preload of the cylindrical spring 19. Further, if the thrust force applied to the orbiting scroll 18 is not point symmetrical with respect to the involute center and the orbiting scroll 18 is tilted, the cylindrical spring 19
As it flexes as shown by the solid line in the figure, the spring force acts in the direction to eliminate the inclination.

Therefore, the seal on the axial end face of the wrap 18b of the orbiting scroll 18 is always perfect, and compressed gas does not leak, thereby preventing a decrease in efficiency. Further, there is no need to seal between the back pressure chamber 20 and the suction hole 9, and therefore, there is no problem of wear between the end plates 17a and 18a of the fixed scroll 17 and the orbiting scroll 18. Furthermore, the structure is simpler than when using a compression spring.

Effects of the Invention As is clear from the above description, the present invention comprises two mutually interlocking scrolls having an end plate and a lap standing upright on the end plate, a block that fixes one of the two scrolls, and a block that prevents the rotation of the other scroll. A cylindrical spring is provided between the block and the rotating scroll to support the rotating scroll and whose axis is substantially parallel to the rotating direction. Furthermore, since low pressure is introduced to the back surface of the scroll that performs an orbiting motion, it maintains a thrust force that is not symmetrical with respect to the center of the involute that acts on the scroll that performs an orbiting motion by compression, and prevents the inclination of the scroll. Correction is performed using spring force, and therefore there is no leakage, which prevents a drop in efficiency. In addition, since low pressure is introduced to the back of the scroll that performs the orbiting movement, there is no need for a seal between the end plates of both scrolls. The structure can be simplified compared to the case where a compression spring made of a coiled spring is used.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional scroll compressor, Fig. 2 is a sectional view taken along the -' line in Fig. 1,
FIG. 3 is a sectional view of a scroll compressor showing an embodiment of the present invention, FIG. 4 is a sectional view taken along the line -' in FIG. 3, and FIG. 5 is an enlarged sectional view of a cylindrical spring portion. 3...Block, 6...Rotation prevention mechanism, 17...
...Fixed scroll, 17a...Fixed scroll end plate, 17b...Fixed scroll wrap, 18
... Orbiting scroll, 18a... Orbiting scroll end plate, 18b... Orbiting scroll wrap, 1
9...Cylindrical spring.

Claims (1)

[Claims] 1. An end plate, two mutually interlocking scrolls having laps standing upright on the end plate, a block for fixing one of the two scrolls, an anti-rotation mechanism for preventing rotation of the other scroll, and a rotation prevention mechanism for preventing rotation of the other scroll; A cylindrical spring is provided between the scroll that moves, supports the scroll that moves, and has its axis substantially parallel to the rotating direction, and the scroll that moves that moves. A scroll compressor in which the entire surface of the end plate opposite to the lap side faces a back pressure chamber into which suction gas is introduced.