JPH04164182A - Scroll type fluid machine - Google Patents

Abstract

PURPOSE:To prevent the fluid leak by supporting the force in the axial direction by a plurality of thrust balls which are held by a retainer ring member and nipped between a fixed scroll side and a swing scroll side. CONSTITUTION:A plurality of pin members 34 installed on a housing 1 side having a fixed scroll 5 are inserted from one side into a groove 29 in the radial direction of a retainer ring member 27, and a plurality of pin members 33 installed on a swing scroll 3 side are inserted from the opposite side to the pin member 34 at the housing 1 side into the other radial direction groove 30. Further, a plurality of thrust balls 26 are inserted and held in a hole an the retainer ring member 27, and support the axial direction force because these thrust balls 26 are nipped between the fixed scroll 5 side and the swing scroll 3 side, and the relative position in the axial direction of the scrolls 5 and 3 is kept constant. Accordingly, sealing performance is improved, and the fluid leak is prevented.

Description

[Detailed description of the invention] [Industrial application field] The present invention is applicable to air compressors, pumps, blowers, etc. 1) The present invention relates to scroll-type fluid machines used in

[Conventional technology]

A scroll type fluid machine meshes a pair of scrolls formed by an involute curve or the like to form one or more arc-shaped compression chambers between them, and
By applying relative rocking motion between these scrolls, the volume of the compression chamber decreases as the compression chamber moves from the outer periphery of each scroll toward the center. The purpose of this is to pressurize the fluid.

When one of a pair of scrolls is fixed to the machine frame as a fixed scroll and the other is made to swing relative to the fixed scroll as an oscillating scroll (movable scroll), the oscillating scroll does not oscillate or revolve. It is necessary to regulate it so that it does not rotate. Many inventions and ideas have been made regarding mechanisms for this purpose, but among them, the first conventional example is Utility Model No. 62-1.
In the device described in 99983, a large number of plate pins fixed to the machine frame side and the same number of movable pins attached to the oscillating scroll are inserted into an annular ring in pairs, so that the movable pins is restrained to prevent the swinging scroll from rotating.

In addition, JP-A-1-262, which will be taken up as a second conventional example,
Publication No. 392 describes a mechanism that can be called a modification of the Oldham joint, and this mechanism consists of a fixed guide pin fixed to the machine frame side and a fixed guide pin fixed to the swinging scroll side at right angles to the fixed guide pin. It consists of turning guide pins and a pin sliding ring in which these guide pins are slidably provided.

[Problem to be solved by the invention]

In the case of a scroll-type fluid machine, when the oscillating scroll is oscillated relative to the fixed scroll as described above, the arc-shaped compression chamber formed between these two scrolls moves toward the center, and As the volume decreases, the pressure of the fluid within the compression chamber increases, creating a force that tends to separate the two scroll portions forming the walls of the compression chamber. This force can be divided into an axial force that attempts to move the oscillating scroll away from the fixed scroll, and a radial force that attempts to change the oscillating radius of the oscillating scroll.

Therefore, in order to prevent pressurized fluid from leaking from the seam (sealing part) of the two scrolls that form the compression chamber, the axial position of the oscillating scroll and the oscillating radius (the fixed It is necessary to reliably support the oscillating scroll in both the axial and radial directions so that the amount of eccentricity relative to the scroll does not change during operation.

However, in the first conventional example, although a large number of plate pins and movable pins are used, at any moment of operation, only one pin acts to prevent the rotation of the oscillating scroll. ~There are only two pins, and the other pins are idle. In addition, two pins are placed inside the annular ring, and the movable pin is rotated around the plate pin with a rotation radius equal to the eccentricity of the eccentric shaft. If you want to reduce the amount of eccentricity itself, the pin diameter needs to be 172 or less than the ring diameter and a value equivalent to the eccentricity, so the pin diameter may be very small.
Problems with the strength of the pin will occur (for example, if the eccentricity is 2 m)
m, a pin with a diameter of 2111111 or less is required)
. Furthermore, even though each pin and ring exhibits a transfer prevention effect only in a specific position, there is also the waste of having to manufacture all of them with high precision. Furthermore, the radius of rotation determined by each ring and pin is
It is necessary to set an appropriate play so as not to interfere with the rotation radius determined by other pin and ring pairs or the eccentric radius of the shaft.

In addition, in the second conventional example, the length of the guide pin is very long, and the pin sliding ring not only slides and supports the guide pin, but also receives thrust force in the axial direction.
It has to be large and durable, the guide pin needs to be thick, and it is necessary to cross the two guide pins, so the intersection of the pins becomes thick and the There are problems such as the need for a special structure.

[Means to solve the problem]

The present invention provides a means for solving the above-mentioned problems, including a plurality of pin members attached to a housing having a fixed scroll and extending in the axial direction, and a rocking member that engages with the fixed scroll and swings. A retainer provided at a position where a plurality of pin members attached to the scroll side and extending in the axial direction and a radial groove that receives and guides these two types of pin members from opposite sides intersect with each other. A rotation prevention and axial force support mechanism comprising a ring member and a plurality of thrust balls held by the retainer ring member and sandwiched between the fixed scroll side and the oscillating scroll side to support axial force. A scroll type fluid machine is provided.

[For production]

A plurality of pin members provided in the axial direction on the housing side having the fixed scroll are inserted from one side into one of the radial grooves provided at orthogonal positions of the retainer ring member, so that the retainer ring member The ring member has a degree of freedom only in the direction of the one groove, and can move only in that direction.

Further, in the other radial groove orthogonal to the one groove of the retainer ring member, a plurality of pin members are provided in the axial direction on the oscillating scroll side from the side opposite to the pin member on the housing side. is inserted, has a degree of freedom only in the direction of the other radial groove, and is movable only in that direction.

Therefore, the oscillating scroll is prevented from rotating with respect to the housing or the fixed scroll, and only oscillation (revolution) is allowed, so that the oscillating scroll performs accurate oscillating motion as a scroll-type fluid machine.

In addition, a plurality of thrust balls are inserted and held in the holes of the retainer ring member, and these thrust balls are held between the fixed scroll side and the oscillating scroll side, so that they are held in the axial direction. supports the force and keeps the relative axial position of both scrolls constant,
Moreover, the friction when the oscillating scroll oscillates relative to the fixed scroll in the presence of an axial force is significantly reduced.

I [Example] Figures 1 to 3 show an example in which the scroll type fluid machine of the present invention is implemented as a compressor.
It mainly consists of a housing 1, a fixed scroll housing 2 fastened to the housing 1 by bolts (not shown), an oscillating scroll 3 that engages with the housing 1, a shaft 4 for driving the oscillating scroll 3, and the like.

The fixed scroll housing 2 has a fixed scroll part 5 therein, and in the case shown in the figure, the fixed scroll housing 2 and the fixed scroll part 5 are formed as one body, but they are separated. They may be made as solid pieces and fixed to each other.

The fixed scroll portion 5 is formed of a spiral wall, and a discharge port 6 is provided at the center of the innermost circumference. This discharge port 6 is opened toward the outside of the fixed scroll housing 2, and a discharge check valve 7 is provided so as to close the opening.

This discharge check valve 7 is connected to the discharge port 6 by a spring 8.
The pressure on the discharge port 6 side is applied to the spring 8.
The fluid is allowed to flow out from the discharge port 6 only when the above is overcome. In the illustrated embodiment, this spring 8
and discharge check valve 7 are held by holder 9,
The discharge check valve 7 is internally movable by the stroke allowed by the holder 9. This holder 9 holds the discharge check valve 7 and the spring 8, and has a structure that allows fluid to escape to the rear thereof.

Further behind the seal 11 is a port 10 that fixes the holder 9 to the fixed scroll housing 2 and serves as a connection part of the sleeve that sends the discharged fluid to the outside.
It is screwed onto the fixed scroll housing 2 with the two sides in between.

The housing 1 to which the fixed scroll housing 2 is fixed forms the main outer shell of this compressor, and has a hollow cylindrical shape, and one end surface is precisely connected to the fixed scroll housing 2. Therefore, mutual positioning is performed via pins 12 (FIG. 3). Moreover, precisely positioned bearings 13 and 14 are held inside the housing 1, and these bearings 13 and 14 hold the shaft 4 on their inner ring sides, so that the axis of the shaft 4 is aligned with the fixed scroll housing. It is in a state where it is positioned with sufficient accuracy with respect to 2. The shaft 4 has one end protruding toward the right end surface of the cylindrical housing 1 in FIG. 1, and forms a connecting portion 15 with a drive source. The other end extends toward the fixed scroll housing, and an eccentric shaft 16 and a balancer holder 17 are formed at the tip thereof. Although both the eccentric shaft 16 and the balancer holder 17 are integral with the shaft 4, they are at positions offset from each other in substantially opposite directions with respect to the axis of rotation of the shaft 4. The balancer holder 17 has a balancer 18.
19 is fixed by means such as a screw, and rotates together with the shaft 4. Since the eccentric shaft 16 is eccentric with respect to the shaft 4 by a precisely determined amount, when the connection part I5 of the shaft 4 with the drive source is rotated, the eccentric shaft 16
The shaft 4 rotates with rocking around the rotation axis of the shaft 4, which is defined relative to the fixed scroll housing 2. The eccentric shaft 16 is a precision cylindrical shaft, into which a bearing 20 press-fitted and fixed to the orbiting scroll 3 is rotatably fitted. That is, the oscillating scroll 3 is supported by this eccentric shaft 16 and has the same center. An oscillating scroll section 21 corresponding to the fixed scroll section 5 is formed on the opposite side of the oscillating scroll 3 from the bearing 20 . The fixed scroll section 5 and the swinging scroll section 21 are a combination of scroll grooves and teeth that are mutually received. In addition, the height of the teeth or the depth of the groove of each scroll part is equal to each other, and the two scroll parts 5.21 can slide in the axial direction with the tips of the teeth and the bottom of the groove lightly touching each other. However, in order to avoid damage and wear due to mutual sliding, the tip seals 22 and 23 made of wear-resistant sealing material are fitted at the tip of each tooth. There is. In addition, the dimensions of the teeth of each scroll are as follows: the thickness of the teeth is t1, the width of the groove is d, and the subscript on the oscillating scroll 3 side is m.
, the subscript representing the fixed scroll housing 2 side is f,
If the amount of eccentricity of the eccentric shaft 16 with respect to the shaft 4 is δ, then d, -tm! The following relationship is satisfied: -12Xδ a, -tr =2xδ.

A swing race 24 is provided around the holding portion of the bearing 20 of the swing scroll 3. A fixed race 25 is also provided on the inner surface of the housing 1 so as to face the swing race 24. These two races 24 and 25 are connected to the shaft of the oscillating scroll 3 and the housing 1 to which each is attached.
The two opposing races 24, 25 have surfaces parallel to each other, so that the two opposing races 24, 25 have surfaces parallel to each other. A plurality of thrust balls 26 are sandwiched between these two surfaces, and the relative movement of the two races 24 and 25 is made possible by the transfer of these holes 26. It prevents A retainer ring 27 for holding a number of thrust balls 26 between the two races 24, 25 is provided between the two races. Further, in order to prevent the retainer ring 27 from tilting or shifting, small diameter holder balls 28 are incorporated in several places on both sides of the retainer ring 27. Since the structure of this part is complex and is the central part of the present invention, an exploded view in the axial direction is shown in FIG.

The retainer ring 27 has a hole or the like for accommodating and positioning the thrust ball 26, and also has hemispherical recesses for holding the holder ball 28 on both sides.

The depth of this holding portion is set so that the height between the holder balls 28 held on opposite sides is slightly smaller than the diameter of the thrust ball 26.

In addition to these, the retainer ring 27 has two types of grooves 29 and 30 as two diametric notches perpendicular to each other.
is provided. These grooves 29, 30 have two parallel faces, and their width is large enough to accommodate, with slight play, the outer ring of a small-diameter bearing 31, 32 attached to a pin, which will be described later. To explain this part in more detail,
FIG. 3 shows a cross section (8-0-B in FIG. 2) passing through the two types of grooves 29 and 30 of the retainer ring 27. (By the way, Figure 1 is C-○-D in Figure 2.
It corresponds to a cross section. ) The bearing 32 that engages with the groove 30 has its inner side fitted into a pin 33 that is press-fitted and fixed to the back surface of the oscillating scroll 3 so as to be freely movable, while the bearing 3I that engages with the groove 29 is inserted into the housing. The pin 34 is press-fitted into the pin 34 and is removably inserted into the pin 34. With the above configuration, the retainer ring 27
is movable relative to the housing 1 only in the direction of the groove 29 by shifting the pin 34 fixed to the housing 1 and the bearing 31 fitted therein.

On the other hand, the oscillating scroll 3 and the retainer ring 27 are also in a state where they can move relative to each other only in the direction of the groove 3o due to the rolling of the pin 33 and the bearing 32. Even when the shaft 4 rotates, the scroll 3 can move only in the composite direction of the two directions of the grooves 29 and 30, and as a result of suppressing relative rotation, it performs a so-called rocking motion.

Figure 4 shows an operational diagram of the scroll compressor.

This figure is shown as a cross section taken along a plane perpendicular to the axis, and in the axial direction, it is sealed on two surfaces parallel to the plane of the paper. The oscillating scroll section 21 has a similar spiral shape to the fixed scroll section 5, and the oscillating scroll 3 remains oscillated at an angle shifted by 180 degrees from each other, and the volume of the chamber 35 formed between the two scrolls is increased. is moved toward the center of the scroll while decreasing. This process is continuously performed to compress the fluid, but since the basic operations thereof are well known, a detailed explanation will be omitted.

In order to perform this compression and transfer more reliably, the compressed chamber 35
It is necessary to ensure that the seal is properly sealed. The present invention aims to improve this part.

In FIG. 1, when the connecting portion 15 of the shaft 4 is rotated by external power, the eccentric shaft 16 at the tip also rotates around the axis of the shaft 4, and the The swinging scroll 3 also tries to rotate in the same way. However, as described above, the grooves 29 and 30 of the retainer ring 27 and the bearings 31 and 32 cause the swinging scroll 3 to swing with respect to the housing 1 without changing its relative angle. Therefore, as shown in FIG.
is compressed and guided to the center. The fluid compressed within the chamber 35 is then discharged toward the discharge port 6 at the center.

In this process, as the internal pressure of the chamber 35 and the like rises, a force acts on the oscillating scroll 3 in the axial direction to the right in FIG. 1. However, this force is
5 to the thrust ball 26, and the housing 1
Since the swing scroll 3 is supported by the race 25 provided on the side thereof, the swing scroll 3 does not separate from the fixed scroll housing 2. Thereby, the two scroll parts 5 and 2
Tip seals 22 and 23 attached to each tip of 1
However, a good sealing condition can be maintained with the sealing surface. FIG. 5 shows changes in the positional relationship between the retainer ring 27 and the orbiting scroll 3 with respect to the housing 1 during the above operation.

Next, in Figure 4, (a) → (b) → (C) → (d)
Looking at the chamber 35 that is being compressed, as mentioned above, axial sealing is achieved by the axial support by the thrust ball 26 and the tip seals 22 and 23, but radial sealing is achieved by the two parts forming the chamber 35. This is achieved by portions (sealing portions) 36 and 37 where the scroll portions 5 and 21 are in contact with each other or close to each other with a very narrow gap at both ends of the chamber 35. These two seal parts 36 and 37 are
According to the relative rocking movement of the two scroll parts 5 and 21,
The movement progresses as shown in (a) → (b) → (C) → (d) in FIG. It is necessary to perform the rocking while keeping 5 and 21 as close as possible. Of course, if the two scroll parts 5 and 21 come into contact at the seal parts 36 and 37 and the gap becomes 0, the sealing condition will be the best, but since abrasion occurs during the rocking process, it is impossible to bring them into contact with strong force. . In other words,
It is necessary to swing the swinging scroll 3 while maintaining a very close distance relationship between the two scroll parts 5 and 21, such that the two scroll parts 5 and 21 touch each other or not, or separate or do not separate. This is particularly important when realizing a non-lubricated scroll type fluid machine. This is because the sealing effect of the lubricating oil and the friction prevention effect when the two scroll parts 5 and 21 come into contact cannot be expected.

In order to obtain accurate relative motion between these two scroll parts 5 and 21, in addition to increasing the machining accuracy of both scroll parts, ■ accurate positioning of the shaft 4, and ■ eccentricity of the eccentric shaft 16 with respect to the shaft 4. (1) Prevention of relative rotation of both scroll parts 5 and 21, etc. are necessary conditions. Among these, point (2) depends on the machining accuracy of the shaft 4 and housing 1, but point (2) can be achieved with high precision by implementing the present invention.

Compared to the first conventional example described above, in the case of the present invention, pin 3
The number of pins 33 and 34 is small, and these pins 33 and 34 always have the effect of preventing the orbiting scroll 3 from rotating at any rotation angle of the shaft 4. Also, each pin 33.34
moves in only one direction via the retainer ring 27 and bearings 31, 32, and is not affected by the amount of eccentricity. In other words, the diameter of the pins 33 and 34 can be set regardless of the amount of eccentricity, and since the manufacturing accuracy and dimensions are unrelated to the amount of eccentricity, even if the play is small, it will hinder eccentric rotation. There isn't. Moreover, since the play can be reduced to a minute value, a more accurate transfer prevention effect can be obtained.

Furthermore, compared to the second conventional example, in the case of the present invention, since the axial force is received by the thrust ball 26, it is possible to use smaller bearings 31, 32 and pins 33, 34. The length of pins 33 and 34 is the bearing 31
．． It can be as short as necessary to insert 32.

Furthermore, as a result, the groove 29.3 of the retainer ring 27
Since the pins 33 and 34 can be accommodated from both sides in the 0, and the space between them is also used to accommodate the thrust ball 26, the wall thickness of the anti-rotation mechanism is extremely thin, making it more compact. It will be advantageous for. Moreover, since a pin of a special shape is not required, the cost does not increase.

In the embodiment shown in FIG. 1, the fixed scroll housing 2 and the scroll portion 5 are integral, but they may be molded and processed as separate parts and then fixed to each other by fastening means. Further, although the races 24 and 25 are separate from the swinging scroll 3 and the housing 1, it goes without saying that they may be constructed as one piece.

Furthermore, the grooves 29 and 30 do not have to be perpendicular to each other (in short, they only need to intersect).

〔Effect of the invention〕

According to the present invention, since the rotation of the oscillating scroll with respect to the fixed scroll is completely prevented and the axial position is accurately maintained, the sealing property of the arc-shaped compression chamber formed between both scrolls is improved. The leakage of fluid from the chamber is reduced, and the efficiency of the fluid machine is improved.

Furthermore, the structure of the rotation prevention and axial force support mechanism is simple, and it is easy to make it compact and robust, and there are few parts that require high-precision machining, which reduces costs.

Furthermore, since this mechanism uses rolling thrust balls to support the axial force, there is less friction due to the swinging of the swinging scroll during operation, and less power is required for driving.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view showing an embodiment of the present invention, Fig. 2 is an exploded perspective view of the main parts, Fig. 3 is a longitudinal sectional view showing a cross section different from Fig. 1, and Fig. 4 is a general view. FIG. 5 is a diagram illustrating the function of the scroll in a scroll-type fluid machine, and FIG. 5 is a diagram illustrating the function of preventing rotation according to the present invention. DESCRIPTION OF SYMBOLS 1... Housing, 2... Fixed scroll housing, 3... Oscillating scroll part 4... Shaft, 5
...Fixed scroll part, 6...Discharge port, 7...
・Discharge check valve, end...spring, 9...holder,
10...Port, 11...Seal,
12...pin, 13.14...bearing,
15... Connection part, 16... Eccentric shaft, 17... Balancer holder, 18.19... Balancer, 20... Bearing, 21... Oscillating scroll part, 22.23... Chip Sea Nope 24... Swing race, 25... Fixed race, 26... Thrust ball, 27... Retainer ring, 28... Holder ball, 29.30... Groove, 31.32...・
Bearing, 33.34... Pin, 35... Chamber, 36.37... Radial seal portion. (C) Q (b) (C1) 677-

Claims (1)

[Claims] a plurality of pin members attached to a housing side having a fixed scroll and extending in the axial direction; a plurality of pin members attached to an oscillating scroll side that engages with the fixed scroll and oscillates and extends in the axial direction; a retainer ring member provided at a position where radial grooves for receiving and guiding these two types of pin members from opposite sides of each other intersect with each other; A scroll-type fluid machine characterized by comprising a rotation prevention and axial force support mechanism consisting of a plurality of thrust balls that are sandwiched between an oscillating scroll side and support an axial force.