JPH0643513Y2 - Scroll compressor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a scroll compressor used in an air compressor, a refrigerant compressor, or the like, and more specifically to an axial shape of a scroll side plate of the scroll compressor.

[Conventional technology]

Conventionally, the scroll compressor was basically constructed as shown in FIG. In FIG. 4, 1 is a fixed scroll, 2 is an orbiting scroll, 1a is a discharge port, P is a compression chamber, O is a fixed point on the fixed scroll 1, and O'is a fixed point on the orbiting scroll 2. In the fixed scroll 1 and the orbiting scroll 2, as shown in FIG. 5, spiral side plates 101, 20 having the same shape but opposite winding directions on the base plate, respectively.
1 are integrally formed and combined with each other as shown in FIGS. 4 and 5, and at each point B, the spiral side plates 101, 20
1 are in contact with each other on their axial side surfaces. This spiral side plate 1
The shapes of 01 and 201 are formed by an involute curve or the like, as is conventionally known.

Next, the operation of this scroll compressor will be described.

In FIG. 4, the fixed scroll 1 is stationary with respect to the space, and the orbiting scroll 2 is combined with the fixed scroll 1 as shown in the figure, and performs a rotational motion without changing its posture with respect to the space. , 0 °, 90 °, 180 ° and 270 ° as shown in FIGS. 4 (a) to 4 (d). With the movement of the orbiting scroll 2, each point B moves toward the center, and the crescent-shaped compression chamber P formed between the fixed scroll spiral side plate 101 and the orbiting scroll spiral side plate 201 sequentially decreases its volume. The gas taken into the compression chamber P is compressed and discharged from the discharge port 1a. During this period, the distance between the fixed points O to O'of each scroll is kept constant, and if the gap between the spiral side plates 101 and 201 is represented by Z and the thickness is represented by t, then
O '= Z / 2-t. Z corresponds to the pitch of the spiral side plates 101 and 201.

A specific configuration of such a scroll compressor that operates according to the operation principle will be described with reference to FIG. FIG. 5 shows an example disclosed in JP-A-60-24330,
In the figure, 1 is a fixed scroll, 2 is an orbiting scroll, 1a is a discharge port, P is a compression chamber, 1b is a suction port, 3 is a main shaft, and 4 is a frame. Reference numerals 101 and 201 denote spiral side plates of the fixed scroll 1 and the orbiting scroll 2, respectively, and reference numerals 102 and 202 denote base plates of the fixed scroll 1 and the orbiting scroll 2, respectively. Also, A is the end faces 101a, 201a of the spiral side plates 101, 201 and the bottom faces 202a, 10a of the mating base plates 202, 102 which are in contact with the end faces 101a, 201a, respectively.
It is an axial gap with 2a.

Here, the orbiting scroll 2 is fixed to the fixed scroll 1 in a state where the surface opposite to the surface on which the spiral side plate 201 is formed is supported by the frame 4 and the fixed scroll 1 as shown in FIG. The scroll 1 is fixed to the frame 4. When the main shaft 3 rotates as shown by the arrow, the orbiting scroll 2 connected to the main shaft 3 starts to move, but the orbiting scroll 2 performs a revolving motion without rotation by a rotation preventing device (not shown). As a result, the fluid to be compressed is sucked from the suction port 1b, compressed according to the operating principle shown in FIG. 4, and discharged from the discharge port 1a.

In such a compressor, the radial seal, that is, the leakage in the radial direction of the spiral through the gap A, is relatively large compared to the fluid intake volume because the leak line length corresponds to the longitudinal length of the spiral. It greatly affects the efficiency of the machine. As a method for sealing in the radial direction, means for preventing the leakage of the fluid to be compressed by making the gap A small, for example, sucking oil together with the fluid to be compressed through the suction port 1b and forming an oil film in the minute gap A However, in order to uniformly provide such a minute gap, the dimensional accuracy of each part such as the fixed scroll 1, the orbiting scroll 2 and the frame 4 is required to be high. In some cases, each part may be selected at the time of assembly. There was a problem in workability and assembling, such as having to fit them. Further, during operation, the temperature in the vicinity of the discharge port 1a becomes high due to the compressed fluid. As a result, if the local thermal expansion exceeds the minute gap A or more, there is no escape and seizure occurs. Therefore, assuming the amount of thermal expansion, it is necessary to uniformly increase the gap in the entire A surface in advance, but if this is done, it will be more than the optimum gap required to form an effective oil film. As a result, there were many cases in which there was a large amount of leakage and the sealing effect was not achieved.

On the other hand, in addition to such non-contact seals, spiral side plates 101, 20
A method is considered in which a groove is formed on the end face of 1 along the longitudinal direction of the spiral, a sealing material is fitted into the groove, and leakage is prevented by a contact seal.

An example of such a sealing method will be described with reference to FIGS. That is, FIG. 6 is a partial cross-sectional view in the vicinity of the portion A between the base plate side surface 102a of the fixed scroll 1 and the spiral side plate end surface 201a of the orbiting scroll 2, which is an end surface 201 of the spiral side plate 201.
A groove 5 having a rectangular cross-section that opens along the longitudinal direction of the spiral is formed in a, and a seal material 6 having the same shape as the groove 5 is formed in the groove 5 so that an end surface 6a of the seal material is in close contact with the bottom surface 102a of the fixed scroll base plate 102a. To prevent gas from leaking, and to seal the back surface 6c and groove bottom
It is fitted so as to form a gap with 5a.

In such a sealing method, sealing can be effectively performed against leakage in the radial direction of the spiral through the gap A between the end surface of the spiral side plate and the bottom surface of the base plate. Also, the sealing material 6 is the groove bottom 5a.
Since it can escape in the direction, seizure due to thermal expansion of the sealing material end surface 6a does not occur. However, the spiral side plates 101, 20
Between the compression chambers P partitioned by the points B with one another, when the gap A is large, the compressed fluid tends to leak along the side surface 6b of the protruding portion of the sealing material in the spiral longitudinal direction.

That is, FIG. 7 is a partial cross-sectional view of the vicinity of the contact points B of the spiral side plates 101, 201 as seen from above, and FIG. 8 is a fragmentary perspective view of the spiral side plates 101, 201. As shown by the solid arrow from the high pressure side compression chamber P _H ,
The state where gas leaks to the low pressure side compression chamber P _L on the downstream side along the side surface 6b of the protruding portion of the sealing material is shown.

[Problems to be solved by the invention]

As described above, although the above-described type of sealing method effectively seals in the radial direction, there is a gap along the side surface 6b of the protruding portion of the sealing material, so that leakage in the spiral longitudinal direction inevitably occurs and compression efficiency is improved. That is, the deterioration of performance cannot be avoided. In particular, in consideration of seizure due to thermal expansion of the inner peripheral side end surface of the spiral side plate, when the axial height of the spiral side plates 101, 201 is made low and the gap A is made large, the longitudinal length is increased at the outer peripheral part of the spiral side plate with small thermal expansion. Directional leakage increases.

As described above, the conventional sealing method has the contradictory problems of improving reliability by preventing seizure and preventing performance deterioration due to gas leakage.

The purpose of the present invention is to solve the above-mentioned conventional problems, and it is possible to prevent seizure on the inner peripheral side of the spiral side plate to improve reliability and prevent leakage on the outer peripheral side of the spiral side plate. It is to provide an efficient scroll compressor.

[Means for solving problems]

A scroll compressor according to the present invention includes a fixed scroll and a orbiting scroll that are rotatably supported, which are formed by spirally forming side plates protruding from an end plate surface and are combined with each other.
The fixed scroll and the orbiting scroll are fitted into a groove formed along the spiral longitudinal direction on the spiral side plate end faces and slidably contact each other on the opposite end plate faces of the scrolls. In a scroll compressor provided with a seal member that seals a leakage of a compressed fluid between a side plate end surface of a scroll and an end plate surface of the scroll on the opposite side, spiral side plates of both scrolls have inner peripheral sides. The axial height of the portion surrounding the discharge-side compression chamber having the largest volume formed at the moment when the tip is separated from the spiral side plate of the counterpart scroll is lower than the other outer peripheral portions.

[Action]

According to the scroll compressor of the present invention, the inner peripheral side of the spiral side plate is lower than the outer peripheral side, and the axial gap on the inner peripheral side is larger. Even if the axial gap on the outer peripheral side is set to be small to prevent leakage in the longitudinal direction, the axial gap on the inner peripheral side is sufficiently large. Prevents seizure from touching.

〔Example〕

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

FIG. 1 is a perspective view of the orbiting scroll 2, and FIG. 2 is a sectional view taken along the axial direction when the fixed scroll 1 and the orbiting scroll 2 are combined. In the figure, 1 is a fixed scroll, 11
1, 121a are the inner and outer peripheral sides of the fixed scroll spiral side plate, 111a and 121a are the inner and outer peripheral side end surfaces, and 102a are the same.
a is the bottom of the fixed scroll base plate, 2 is an orbiting scroll, 21
1, 221 are inner and outer peripheral sides of the orbiting scroll spiral side plate, and 211a, 221a are inner and outer peripheral end surfaces,
a is the bottom of the orbiting scroll base plate, 6 is a sealing material, and 6a, 6b, 6c
Represents the end face, side face and back face of the sealing material, and 5a represents the bottom of the groove provided in the spiral side plate.

The definition of the inner side and the outer side of the spiral side plate in the present invention will be described with reference to FIG. In Figure 3, 131,23
Reference numeral 1 denotes the inner peripheral side tips of the spiral side plates of the fixed scroll 1 and the orbiting scroll 2, respectively, and in FIG.
131 and 231 are points 2 on the spiral side plate of the orbiting scroll 2.
32 and the point 132 on the spiral side plate of the fixed scroll 1 are in contact with each other, and the points 131 to 132 on the spiral side plate of the fixed scroll 1 and the points 231 to 232 on the spiral side plate of the orbiting scroll 2 are in contact with each other. A discharge side compression chamber P ₁ is formed so as to be surrounded and surrounded. Further, 133a and 134a are points on the spiral side plate of the fixed scroll 1 and 233a and 234a are points on the spiral side plate of the orbiting scroll 2. In FIG. 3 (a), the points 133a, 234a, and 134a are shown. The points 233a are in contact with each other, and the points 131 to 133 on the spiral side plate of the fixed scroll 1
Point up to a and point 2 on the scroll side plate of the orbiting scroll 2
Surrounded by the portion from 32 to point 234a, the intermediate pressure compression chamber
P ₂ is formed and a point 231 on the spiral side plate of the orbiting scroll ₂ is formed.
To the point 233a and the portion from the point 132 to the point 134a on the spiral side plate of the fixed scroll 1, the intermediate pressure compression chamber P ₃ is formed.

Now, when the orbiting scroll 2 oscillates and rotates from the state of FIG. 3 (a), as shown in FIG. 3 (b), the inner peripheral side tips 131, 231 of the spiral side plates of the fixed scroll 1 and the orbiting scroll 2 are shown.
Are separated from the spiral side plate of the opposite scroll, and the compression chambers P ₁ , P ₂ , and P ₃ communicate with each other. At the moment when the compression chambers P ₁ , P ₂ and P ₃ communicate, the contact points of both scrolls in Fig. 3 (a)
133a and 234a and 134a and 233a move to points 133b and 234b and 134b and 233b in FIG. 3 (b) respectively, and a discharge side compression chamber P ₄ is newly formed with these points as boundaries. The discharge side compression chamber P ₄ formed at the moment when the inner peripheral ends 131, 231 of the scroll side plates of both scrolls are separated from the spiral side plates of the opposite scroll, has the largest volume in the entire compression stroke as the discharge side compression chamber, Further, since the discharge side compression chamber is filled with the discharge gas, the temperature of the portion forming the discharge side compression chamber in the spiral side plate becomes higher than the temperature of other portions. Particularly when the backflow of the high-pressure side refrigerant gas occurs from the discharge port 1a depending on the operating conditions, the temperature difference with other parts becomes further large. Therefore, in the spiral side plate, the inner peripheral side tips of both scrolls form the discharge side compression chamber at the moment when the inner peripheral side tips of both scrolls separate from the spiral side plate of the other side scroll, that is, in FIG. When it is separated from the spiral side plate of, the part from point 131 to point 134b and point 231 to point 234b
The parts up to are defined as the inner peripheral side of the spiral side plate, and the other parts are defined as the outer peripheral side.

Returning to FIG. 1 and FIG. 2, h _i and h _o are axial heights of the inner and outer circumference sides of the spiral side plate, and δ _i and δ _o are inner and outer end surfaces of the spiral side plate, respectively. And the bottom surface of the other side of the scroll base plate, that is, the inner and outer peripheral axial gaps excluding the sealing material, Δh indicates the difference in height between the outer peripheral side and the inner peripheral side of the spiral side plate, and part C indicates the spiral. The boundary between the inner peripheral side and the outer peripheral side of the side plate is shown.

The height of the end surface of the spiral side plate is a constant value of h _o on the outer peripheral side 221a, but as shown in FIG. 1, it decreases stepwise by Δh at the C portion, and the height on the inner peripheral side 211a is It becomes a constant value h _i . Since h _i = h _o −Δh and the distance between the base plates of both scrolls is constant, that is, h _i + δ _i = h _o + δ _o
i = δ _o + Δh. That is, the axial gap δ _i on the inner peripheral side 211 of the spiral side plate is larger than the axial gap δ _o on the outer peripheral side 221 by Δh. Here, the bottom 202a of the scroll base plate
To the end face 6a of the sealing material is constant irrespective of the inner peripheral side and the outer peripheral side, and the sealing material rear surface 6c and the spiral side plate groove bottom portion 5a.
There is a gap between and. The shape of the spiral side plate is the same for the fixed scroll 1.

In a scroll compressor having a fixed scroll and an orbiting scroll having the above-described structure, even if the axial height h _i of the spiral side plate inner peripheral sides 111, 211 increases during operation due to thermal expansion, Axial height h of side 111, 211
_{Since i} is set to be smaller than the outer peripheral sides 121 and 221, the spiral side plate end surfaces 111a and 211a are aligned with the counterpart scroll base plate surfaces 202a and 102a.
No seizure will occur on contact with 2a. Also, the outer peripheral side 121,
Since the axial gap δ _o of 221 is small, the leakage of compressed fluid in the longitudinal direction is also small, and the performance does not deteriorate. Since the axial height of the seal material end surface 6a is constant, the seal material end surface 6a on the inner peripheral side is transferred to the mating scroll base plate bottom surface 10 due to thermal expansion.
Although it is pressed against 2a or 202a, there is a gap between the bottom 5a of the groove provided in the spiral side plate and the back surface 6c of the sealing material,
Since the sealing material 6 can escape in the groove bottom 5a direction,
The seizure of the end surface 6a of the sealing material does not occur.

Although the axial height of the inner peripheral side of the spiral side plate is stepwise lower than that of the outer peripheral side in the above-described embodiment, it may be continuously reduced. Further, the sealing material is not limited to the above-described type, but may be, for example, a type in which a follow-up contact seal is performed by applying some force to the back surface of the sealing material.

[Effect of device]

As described above, according to the present invention, the fixed scroll and the orbiting scroll which are rotatably supported are formed by combining the spiral side plates protruding from the end plate surface, and are combined with each other. Fitted in a groove formed along the longitudinal direction of the spiral side plate end face with the orbiting scroll and slidably contacting the end plate faces of the scrolls on the opposite side with the side plate end faces of the scrolls. In a scroll compressor provided with a seal member for respectively sealing leakage of compressed fluid between the end plate surface of the scroll on the other side,
The spiral side plates of both scrolls have an axial height of a portion surrounding the discharge-side compression chamber having the largest volume formed at the moment when the inner peripheral end of each scroll separates from the spiral side plate of the opposite scroll. Since it is configured to be lower than the other outer peripheral portions, seizure of the spiral side plate does not occur, performance does not deteriorate due to leakage of compressed fluid in the longitudinal direction, and a highly reliable and highly efficient scroll compressor can be obtained.

[Brief description of drawings]

1 is a perspective view showing an orbiting scroll of a scroll compressor according to an embodiment of the present invention, and FIG. 2 is a sectional view showing a fixed and orbiting scroll of the scroll compressor.
3 (a) and 3 (b) are explanatory views showing the inner peripheral side and the outer peripheral side of the spiral side plate in the fixed and orbiting scrolls, and FIGS. 4 (a) to 4 (d) are scroll compressions. FIG. 5 is an explanatory view showing the operating principle of the machine, FIG. 5 is a sectional view showing a conventional scroll compressor, and FIGS. 6, 7, and 8 are partial views showing a sealing structure of each part in the conventional scroll compressor. FIG. 1 ... Fixed scroll, 2 ... Swing scroll, 5 ...
Grooves, 6 ...... sealant, P ₄ ...... discharge side compression chamber. In the drawings, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] 1. A fixed scroll which is formed by projecting a spiral side plate on an end plate surface and is combined with each other, an orbiting scroll which is rotatably supported, and a spiral of the fixed scroll and the orbiting scroll. -Shaped side plate end faces are fitted into grooves formed along the longitudinal direction of the spiral and slidably contact each other with the end plate faces of the scrolls on the opposite side, and the side plate end faces of the both scrolls and the scroll on the opposite side. In a scroll compressor provided with a seal member for respectively sealing leakage of compressed fluid between the end plate surface, the spiral side plates of both scrolls have inner ends on the inner peripheral side of the spiral side plate of the opposite scroll. A scroll compressor characterized in that the axial height of the portion surrounding the discharge-side compression chamber having the largest volume formed at the moment of separation is made lower than the other peripheral portions.