JPH1150979A - Displacement fluid machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a discharging valve easily manufactured, assembled and adjusted, in a displacement fluid machine in which one space is formed of a cylinder inner wall surface and a displacer outer wall surface when a displacer and a cylinder are arranged between end plates and the cylinder center and the displacer center are matched to each other, and a plurality of spaces are formed when the positional relationship of the displacer and the cylinder is in the turning position. SOLUTION: A plurality of discharging ports 8a corresponding to the number of working chambers are provided on an end plate-shaped sub bearing 8 laminated on a plate-shaped cylinder member, and discharging valves 9 are arranged. A valve part 94 having elasticity is brought in contact with a valve seat 84 formed on the outlet side of each discharging port 8a, and a plurality of valve parts 94 and stopper parts 104 are provided on valve plates 90 and retainers 100 as plate materials for constituting the discharging valves 9 whose lift amount H is regulated by the stopper parts 104.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pump, a compressor, an expander, and the like, and more particularly, to a positive displacement fluid machine.

[0002]

2. Description of the Related Art A reciprocating type fluid machine which moves a working fluid by repeating a reciprocating motion of a piston in a cylindrical cylinder has been used as a positive displacement type fluid machine, and a cylindrical piston has been eccentric in a cylindrical cylinder. A rotary (rolling piston type) fluid machine that moves a working fluid by rotating, meshing a pair of fixed scroll and orbiting scroll having an upright spiral wrap on an end plate, and orbiting the orbiting scroll. 2. Description of the Related Art A scroll type fluid machine that moves a working fluid by a hydraulic fluid is known.

[0003] Reciprocating fluid machines have the advantage of being easy and inexpensive to manufacture because of their simple structure, but the stroke from the end of suction to the end of discharge is as short as 180 ° in terms of the rotation angle of the rotating shaft. The problem is that the flow velocity in the discharge process is high, the performance is reduced due to the increase in pressure loss, and the reciprocating motion of the piston makes it impossible to completely balance the unbalanced inertial force of the rotating shaft system. There is a problem that is large.

[0004] In the rotary type fluid machine, although the stroke from the end of suction to the end of discharge is 360 ° in the rotation angle of the rotating shaft, the problem that the pressure loss in the discharge process increases is smaller than that of the reciprocating type fluid machine. Since the gas is discharged once per rotation of the shaft, the fluctuation of the gas compression torque is relatively large, and there is a problem of vibration and noise as in the reciprocating fluid machine.

Further, in the scroll type fluid machine, the stroke from the end of the suction to the end of the discharge requires a rotation angle of the rotary shaft of 360 °.
The pressure loss during the discharge process is small due to the long length as described above (usually about 900 ° for air-conditioning applications), and the fluctuations in the gas compression torque during one rotation are generally limited because a plurality of working chambers are formed. There is an advantage that vibration and noise are small. However, it is necessary to manage the clearance between the spiral wrap in the lap meshing state and the clearance between the end plate and the tip of the lap, so that high-precision processing must be performed and the processing cost is high. There is. In addition, there is a problem that the stroke from the end of suction to the end of discharge is as long as 360 ° or more in the rotation angle of the rotating shaft, and the longer the period of the compression process, the more internal leakage increases.

By the way, the displacer for moving the working fluid does not rotate relative to the cylinder into which the working fluid is sucked, but revolves around a substantially constant radius, that is, rotates to convey the working fluid. Japanese Patent Application Laid-Open No. 55-23353 (Reference 1), U.S. Pat.
02869 (Document 3) and JP-A-6-28075
No. 8 (Reference 4). The displacement type fluid machine proposed here comprises a piston having a petal shape in which a plurality of members (vanes) extend radially from the center, and a cylinder having a hollow portion substantially similar to the piston, This piston moves the working fluid by revolving in the cylinder. Also, Japanese Patent Application Laid-Open No. 4-179888 (Document 5)
Discloses a bypass valve provided in a scroll compressor.

[0007]

Problems to be Solved by the Invention Documents 1 to 4 mentioned above
Does not have a reciprocating part unlike the reciprocating type, so that the imbalance of the rotating shaft system can be balanced. Therefore, vibration is small,
Furthermore, since the relative sliding speed between the piston and the cylinder is low, the friction loss can be relatively reduced.

However, the rotation angle of the rotating shaft from the end of suction to the end of discharge of each working chamber formed by the plurality of vanes and cylinders constituting the piston is small,
There will be a time lag (time lag) between the end of the working fluid discharge and the start of the next (compression) stroke (end of suction), and the working chamber from the end of suction to the end of discharge will have a rotating shaft. Since it is formed to be deviated around, the mechanical balance is poor, and the rotation moment acting to rotate the piston itself acts excessively on the piston as a reaction force from the compressed working fluid, and There is a drawback that reliability problems such as friction and wear of the electrode tend to occur. When the positive displacement fluid machine of the present invention is applied to a compressor, the discharge ports of the individual working chambers are arranged on the same circumference with respect to the center axis of the cylinder.

An object of the present invention is to provide a positive displacement fluid machine provided with a discharge valve having a simple structure disposed at the discharge port.

[0010]

In order to achieve the above object, a displacement type fluid machine according to the present invention is arranged such that a displacer and a cylinder are arranged between end plates, and the center of the cylinder is aligned with the center of the displacer. In the displacement type fluid machine, a single space is formed by the inner wall surface of the cylinder and the outer wall surface of the displacer, and a plurality of spaces are formed when the positional relationship between the displacer and the cylinder is set at a turning position. The discharge valve provided in the discharge port is constituted by one retainer laminated on one valve plate having elasticity. A plurality of valve portions corresponding to the plurality of discharge ports are formed on the valve plate, and a stopper for restricting the lift amount of the valve portion is formed on the retainer.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The features of the present invention described above will be further clarified by the following embodiments. Hereinafter, an embodiment of the present invention will be described with reference to the drawings. First, the structure of a positive displacement fluid machine according to one embodiment of the present invention will be described with reference to FIGS. FIG. 1A is a longitudinal sectional view (AA sectional view of FIG. 1B) showing a main part of a hermetic compressor when a positive displacement type fluid machine according to an embodiment of the present invention is used as a compressor. )
FIG. 2A is a plan view showing a state in which a compression chamber is formed as viewed in the direction of the arrow BB in FIG. 2A. FIG. 2 is a diagram showing the principle of operation of the positive displacement compression element. FIG. It is a longitudinal section of a hermetic compressor when used as a compressor.

In FIG. 1, a positive displacement element 1 and an electric element 2 for driving the same are provided in a closed container 3 (not shown).
Is stored. The details of the positive displacement compression element 1 will be described. FIG. 1 (b) shows a combination of three sets of the same contour shape.
A strip wrap is shown. The inner peripheral shape of the cylinder 4 is formed such that the hollow portion has the same shape every 120 ° (center o ′). At the end of each hollow portion, there are a plurality of (in this case, three wraps, there are three) quasi-arc shaped vanes 4b protruding inward. The displacer 5 is disposed inside the cylinder 4 and is shifted from the center of the cylinder 4 by ε so as to mesh with the inner peripheral wall 4a (the portion having a larger curvature than the vane 4b) and the vane 4b. . When the center o ′ of the cylinder 4 and the center o of the displacer 5 are matched,
A gap having a constant width is formed as a basic shape between the two contour shapes.

Next, the operation principle of the positive displacement compression element 1 will be described with reference to FIG.
And FIG. The symbol o is the center of the displacer 5, and the symbol o 'is the center of the cylinder 4 (or the rotating shaft 6). Symbols a, b, c, d, e, and f denote contact points at which the inner peripheral wall 4a and the vane 4b of the cylinder 4 mesh with the displacer 5. Here, looking at the inner peripheral contour shape of the cylinder 4, three combinations of the same curves are connected smoothly in succession at three locations. Focusing on one of these, the curve forming the inner peripheral wall 4a and the vane 4b can be regarded as one thick vortex curve (the tip of the vane 4b is considered to be the beginning of the vortex). The curve (ga) means that the winding angle, which is the sum of the respective arc angles constituting the curve, is approximately 360 ° (the design concept is 360 °, but the value is not exactly the value due to manufacturing errors. Note that this winding angle is a vortex curve of the outer wall curve (g).
-B) is a vortex curve with a winding angle of approximately 360 °. As described above, the one inner peripheral contour shape is formed from the inner wall curve and the outer wall curve. The two spiral curves are arranged at substantially equal pitches (120 ° because they are three wraps), and the outer wall curve and the inner wall curve of the adjacent spiral body are connected smoothly with each other by a smooth connection curve (bb ′) such as an arc. ), The entire inner peripheral contour shape of the cylinder 4 is formed. The outer peripheral shape of the displacer 5 is also configured in the same principle as that of the cylinder 4.

The spiral body composed of three curves is arranged at a substantially equal pitch (120 °) on the circumference. This is for the purpose of uniformly distributing the load accompanying the compressing operation described later and for the purpose of manufacturing. In consideration of easiness, especially when these are not a problem, the pitch may be unequal.

Now, the compression operation by the cylinder 4 and the displacer 5 configured as described above will be described with reference to FIG. Reference numeral 7a denotes a suction port, and 8a denotes a discharge port, which are provided on end plates corresponding to three places, respectively. By rotating the rotating shaft 6, the displacer 5 revolves around the center o ′ of the cylinder 4, which is a fixed side, with a turning radius ε (= oo ′) without rotating around the center o ′, and moves around the center o of the displacer 5. A plurality of working chambers 15 (a plurality of closed spaces surrounded by a cylinder inner peripheral contour (inner wall) and a displacer outer contour (side wall), which are spaces in which suction is completed and a compression (discharge) process is performed. That is, the space from the end of suction to the end of discharge.If the above-mentioned winding angle is 360 °, this space disappears at the end of compression, but the suction ends at that moment. However, when used as a pump, a space communicating with the outside via a discharge port is formed (in this embodiment, three working chambers are always provided).

One hatched working chamber surrounded by the contact points a and b (partitioned at the end of suction, the two working chambers are connected immediately after the compression stroke is started. ). FIG.
(1) is a state in which the suction of the working gas from the suction port 7a into this working chamber is completed. FIG. 2 (2) shows a state in which the 90 ° rotation shaft 6 has rotated from this state, FIG. 2 (3) shows a state in which the rotation has advanced 180 ° from the beginning, and FIG. 2 (3) shows a state in which the rotation has further advanced and has rotated 270 ° from the beginning. It is FIG.2 (4).
When rotated 90 ° from FIG. 2 (4), it returns to the initial state of FIG. 2 (1). As a result, the working chamber 15 reduces its volume as the rotation proceeds, and the discharge port 8a is closed by the discharge valve 9 (shown in FIG. 1), so that the working fluid is compressed.

When the pressure in the working chamber 15 becomes higher than the external discharge pressure, the discharge valve 9 automatically opens due to the pressure difference, and the compressed working gas is discharged through the discharge port 8a. The rotation angle of the rotating shaft from the end of suction (compression start) to the end of discharge is 360 °, and the next suction stroke is prepared while each compression and discharge stroke is being performed. Starts compression. For example, focusing on the space formed by the contacts a and d, the suction has already been started from the suction port 7a at the stage of FIG. 2A, and the volume increases as the rotation progresses. When the state is reached, this space is divided. Fluid corresponding to this divided amount is supplemented from the space formed by the contacts b and e.

The manner of supplementation will be described in detail. FIG.
In the space formed by the contacts a and d adjacent to the working chamber formed by the contacts a and b in the state (1), suction has started. This space is once expanded as shown in FIG. 2 (3), and then divided in FIG. 2 (4). Therefore, not all the fluid in the space formed by the contacts a and d is compressed in the space formed by the contacts a and b. The same amount of fluid as the volume of the fluid that has been divided and not taken into the space formed by the contacts a and d is shown in FIG.
The space formed by the contacts b and e in the suction process in (4) is divided as shown in FIG. 2A, and flows into the space formed by the contacts e and b near the discharge port. Is filled by the flowing fluid. This is because, as described above, the wraps are arranged at a uniform pitch. That is, since the shapes of the displacer and the cylinder are formed by repeating the same contour shape,
Each working chamber can compress substantially the same amount of fluid even if fluid is obtained from different spaces.

Although it is possible to perform processing so that the volumes formed in the respective spaces are equal even if the pitch is not uniform, the productivity is poor. In any of the above prior arts, the space in the suction process is closed and the internal fluid is compressed and discharged as it is, whereas the space in the suction process adjacent to the working chamber is divided in this way. Performing the compression operation is one of the features of the present embodiment.

As described above, the working chambers that perform a continuous compression operation are distributed at substantially equal pitches around the rotary bearing 5a located at the center of the displacer 5, and each of the working chambers has a phase. And the compression is performed. That is,
Focusing on one space, the rotation angle of the rotating shaft is 360 ° from the suction to the discharge, but in the case of the present embodiment, three working chambers are formed and these discharge at a phase shifted by 120 °. When operated as a compressor that compresses a refrigerant that is a fluid, the refrigerant is discharged three times within a rotation angle of 360 ° of the rotating shaft.

Assuming that the space at the moment when the compression operation is completed (the space surrounded by the contact points a and b) is one space, when the winding angle is 360 ° as in this embodiment, any compression Even in the machine operating state, the space in the suction stroke and the space in the compression stroke are designed to be alternated, so that the next compression stroke is started immediately after the compression stroke is completed. Fluid can be compressed smoothly and continuously.

Next, the volume having such a shape (turning)
A compressor incorporating the mold compression element 1 will be described with reference to FIGS. In FIG. 3, in addition to the cylinder 4 and the displacer 5 described in detail above, a revolving-type compression element 1 includes a rotary shaft 6 for driving the displacer 5 by driving a displacer 5 with a crank 6a fitted into a bearing at the center of the displacer 5. A main bearing 7 and an auxiliary bearing 8 which also serve as an end plate for closing both end openings of the cylinder 4 and a bearing for supporting the rotary shaft 6, a suction port 7a formed on an end plate of the main bearing 7, It has a discharge port 8a formed on the end plate of the bearing 8, and a discharge valve 9 for opening and closing the discharge port 8a with a differential pressure. However, the discharge valve 9 may be of a reed valve type. 5b is a through hole formed in the displacer 5. Reference numeral 10 denotes a suction cover attached to the main bearing 7, and reference numeral 11 denotes a discharge cover for integrally forming the discharge chamber 8b with the sub bearing 8.

The electric element 2 includes a stator 2a and a rotor 2b, and the rotor 2b is fixed to the rotating shaft 6 by shrink fitting or the like. The electric element 2 is constituted by a brushless motor for improving electric motor efficiency, and is driven and controlled by a three-phase inverter. However, 2 may be another motor type, for example, a DC motor or an induction motor. Reference numeral 12 denotes a lubricating oil 12 stored at the bottom of the closed container 3, and the lower end of the rotary shaft 6 is immersed therein. 13 is a suction pipe, 1
Reference numeral 4 denotes a discharge pipe, and reference numeral 15 denotes the above-described working chamber formed by engagement of the inner peripheral wall 4a and the vane 4b of the cylinder 4 with the displacer 5. The discharge chamber 8b is separated from the pressure in the closed container 3 by a seal member 16 such as an O-ring.

The flow of the working gas (refrigerant gas) when the displacement type fluid machine in this embodiment is used as an air conditioning compressor will be described with reference to FIG. As indicated by the arrow in the drawing, the working gas that has entered the closed casing 3 through the suction pipe 13 enters the suction cover 10 attached to the main bearing 7, and passes through the suction port 7a to the positive displacement compression element 1. enter,
Here, the rotation of the rotating shaft 6 causes the displacer 5 to perform a revolving motion, and the volume of the working chamber is reduced, so that the working chamber is compressed. The compressed working gas passes through a discharge port 8a formed in the end plate of the sub-bearing 8, pushes up the discharge valve 9, and pushes up the discharge chamber 8
b, and flows out through the discharge pipe 14.
The reason why the gap is formed between the suction pipe 13 and the suction cover 10 is to cool the electric motor element by flowing the working gas into the electric motor element 2 as well.

The lubricating oil 12 stored inside is sent to each sliding portion from the bottom through a hole provided inside the rotary shaft by a differential pressure or centrifugal pump oil to be lubricated. This part is also supplied to the inside of the working chamber through the gap.

Here, an example of a method of forming the contours of the displacer 5 and the cylinder 4 which are the main components constituting the positive displacement compression element 1 of the present invention will be described with reference to FIGS. I will give you an example). FIG. 4 (a)
(B) is an example of the shape of the displacer whose planar shape is formed by a combination of arcs as an example, (a) is a plan view, and (b) is a side view. FIGS. 5A and 5B show FIG.
(A) is a plan view and (b) is a side view of an example of a cylinder shape which meshes with a pair of displacers shown in FIG. FIG. 6 is a diagram in which the center o of the displacer shown in FIG. 4 and the center o ′ of the cylinder shown in FIG.

In FIG. 4 (a), in the planer shape of the displacer, the same contour shape is continuously connected at three places around the center o (center of the equilateral triangle IJK). The contour shape is formed by a total of seven arcs from the radius R1 to the radius R7, and the points p, q, r, s, t, u, v, w
Are connection points of arcs of different radii. The curve pq is
An arc of radius R1 centered on one side IK of the equilateral triangle, where point p is at a distance R7 from vertex I. The curve qr is an arc of a radius R2 having a center on an extension of a straight line connecting the connection point q and the center of the radius R1, and the curve rs is a connection point r and a radius R2.
Similarly, the curve st is a circular arc having a radius R3 having a center on a straight line connecting the connection point s and the center of the radius R3. The curve tu is an arc of a radius R5 having a center on an extension of a straight line connecting the connection point t and the center of the radius R4, and the curve uv is a connection point u and a radius R5
An arc having a radius R6 centered on a centroid o on an extension of a straight line connecting the centers of the circles is a radius R7 centered on a vertex J on a straight line connecting the connection point v and the center (centroid o) of the radius R6. Is an arc.

The radii R1, R2, R3, R4, R5
The angle of each of the arcs of R6 is determined by the condition that the contacts are connected smoothly (the tangents at the contacts have the same inclination). When the contour shape from the point p to the point w is rotated counterclockwise around the centroid o by 120 °, the point p overlaps the point w, and when the contour shape is further rotated by 120 °, the contour shape around the entire circumference is completed. This gives the displacer a planar shape,
The displacer is formed by giving the thickness h. When the plane shape of the displacer is determined, when the displacer makes a swiveling motion with a turning radius ε, the contour shape of the cylinder meshes with the displacer, as shown in FIG. 6, the normal distance outside the curve constituting the contour shape of the displacer. Is an offset curve of ε.

The outline shape of the cylinder will be described with reference to FIG. The triangle IJK is the same equilateral triangle as in FIG. The contour shape is formed by a total of seven circular arcs like the displacer, and the points p ′, q ′, r ′, s ′, t ′,
u ′, v ′, w ′ are connection points of arcs having different radii. A curve p′q ′ is an arc having a radius (R1−ε) centered on one side IK of an equilateral triangle, where the point p ′ is at a distance of (R7 + ε) from the vertex I. The curve q'r 'is an arc of a radius (R2-?) Having a center on an extension of a straight line connecting the connection point q' and the center of the radius (R1-?), And the curve r's 'is a connection point r' and a radius An arc of a radius (R3-ε) having a center on a straight line connecting the center of (R2-ε), and a curve s′t ′ is similarly centered on a straight line connecting s ′ and the center of the radius (R3-ε). This is an arc having a radius (R4 + ε). The curve t'u 'is an arc having a radius (R5 +?) Having a center on an extension of a straight line connecting the connection point t' and the center of the radius (R4 +?), And the curve u'v 'is a curve of the radius of the connection point u' and the radius (R5 +?). An arc of radius (R6 + ε) centered on centroid o ′ on an extension of a straight line connecting the centers,
The curve v′w ′ is an arc having a radius (R7 + ε) centered on a vertex J on a straight line connecting the connection point v ′ and the center (center o ′) of the radius (R6 + ε).

Note that the radii (R1-ε), (R2-ε),
(R3-ε), (R4 + ε), (R5 + ε), (R6 +
The angle of each arc of ε) is determined by the condition that the connection is made smoothly at each contact point (the inclination of the tangent line at the connection point is the same) as in the displacer. The contour shape from the point p 'to the point w' is represented by 12
When rotated by 0 °, the point p ′ coincides with the point w ′, and 12
When rotated by 0 °, the contour shape of the entire circumference is completed. Thereby, the planar shape of the cylinder is obtained. Cylinder thickness H
Is slightly thicker than the thickness h of the displacer.

FIG. 6 is a diagram showing a part of the center o of the displacer and the center o 'of the cylinder overlapped. The gap formed between the displacer and the cylinder is set to ε equal to the turning radius. It is desirable that this gap be ε over the entire circumference. However, within a range where the working chamber formed by the outer peripheral contour of the displacer and the inner peripheral contour of the cylinder operates normally, for some reason, this relationship is not satisfied. There is no problem even if there are collapsed parts.

Although the method of forming the contours of the outer wall of the displacer and the inner wall of the cylinder by combining a plurality of arcs has been described here, the present invention is not limited to this, and the present invention is not limited to this. A similar contour shape can be formed by a combination of curves.

The operation and effect of the embodiment described with reference to FIGS. 1 to 6 will be described below. FIG. 7 shows the volume change characteristic of the working chamber according to the present invention (represented by the ratio between the suction volume Vs and the working chamber volume V) with the rotation angle θ of the rotating shaft from the end of suction as the horizontal axis.
Are shown in comparison with other types of compressors. Accordingly, the volume change characteristic of the positive displacement compression element 1 according to the present embodiment is based on a kind of operating condition of an air conditioner having a discharge start volume ratio of 0.37 (for example, when the working gas is Freon HCFC22, the suction pressure Ps = 0.6).
4MPa, discharge pressure Pd = 2.07MPa), the compression process is almost the same as the reciprocating type, and the compression process is completed in a short time, so that leakage of working gas is reduced, and the capacity and efficiency of the compressor are reduced. Can be improved. On the other hand, the discharge process is about 5 times longer than the rotary type (rolling piston type).
The pressure loss is reduced by 0% longer and the discharge flow rate is reduced, and the fluid loss (excess compression loss) in the discharge process can be greatly reduced to improve the performance.

FIG. 8 shows a change in the amount of work during one rotation of the rotating shaft, that is, a change in the gas compression torque T in this embodiment, in comparison with other types of compressors (where Tm is an average torque). ). Thus, the torque fluctuation of the displacement type compression element 1 of the present invention is very small, about 1/10 of that of the rotary type, and is equivalent to that of the scroll type. Since there is no mechanism for performing the rotation, the vibration and noise of the compressor in which the inertia of the rotary shaft system is balanced can be reduced.

Further, as shown in FIG. 4, since the contour is not a long spiral shape as in a scroll type, the processing time and cost can be reduced, and there is no end plate (end plate) for maintaining the spiral shape. Therefore, as compared with the scroll type, which cannot be processed by penetrating the jig, it can be manufactured by the same processing as the rotary type. Further, since the thrust load due to the gas pressure does not act on the displacer, it is easy to manage the axial clearance which has an important effect on the performance of the compressor as seen in a scroll compressor, so that the performance can be improved. Furthermore, as a result of the calculation,
Compared to scroll compressors with the same volume and outer diameter,
The thickness can be reduced, and the compressor can be reduced in size and weight.

Next, the relationship between the above-mentioned winding angle and the rotation angle θc of the rotating shaft from the end of suction to the end of discharge will be described.
In the above-described embodiment, the winding angle is described as 360 °, but the rotation angle θc of the rotating shaft can be changed by changing the winding angle. For example, in FIG. 2, since the winding angle is 360 °, the rotation angle θc of the rotating shaft from the end of suction to the end of discharge returns to the original state when the rotation angle θc is 360 °. When the rotation angle θc of the rotating shaft from the end of suction to the end of discharge is reduced by making the winding angle smaller than 360 °, a state occurs in which the discharge port communicates with the suction port, and the expansion action of the fluid in the discharge port occurs. This causes a problem that the fluid once sucked flows backward. When the winding angle is larger than 360 °, the rotation angle of the rotating shaft is also larger than 360 °, and two working chambers having different sizes are formed from the end of the suction to the time of communicating with the space having the discharge port. When this is used as a compressor, irreversible mixing loss occurs when the two working chambers merge because the pressure rises of these two working chambers are different from each other, resulting in an increase in compression power. Further, even if it is used as a liquid pump, it is difficult to apply it as a pump because an operation chamber that does not communicate with the discharge port is formed. For this reason, it can be said that the winding angle is desirably 360 ° as much as possible within the range of allowable accuracy.

The rotation angle θc of the rotating shaft in the compression stroke of the fluid machine described in the above-mentioned Japanese Patent Application Laid-Open No. 55-23353 (Reference 1) is θc = 180 °.
The rotation angle θc of the rotating shaft during the compression stroke in the fluid machine described in Japanese Patent Application Laid-Open No. 869 (Reference 3) and Japanese Patent Application Laid-Open No. 6-280758 (Reference 4) is θc = 210 °. In the period from the end of the discharge of the working fluid to the start of the next compression stroke (end of suction), the rotation angle θ of the rotating shaft is described in Reference 1.
c is 180 °, and in References 3 and 4, it is 150 °.

When the rotation angle θc of the rotating shaft during the compression stroke is 210 °, each working chamber (reference numerals I, II,
FIG. 9 (a) shows a compression stroke diagram of the compression strokes indicated by III and IV).
However, the number of rows N = 4. The rotation angle θc of the rotation shaft is 360
Although four working chambers are formed in ゜, the number n of working chambers simultaneously formed at a certain angle is n = 2 or 3. The maximum value of the number of working chambers formed simultaneously is 3, which is smaller than the number of working chambers.

Similarly, FIG. 10A shows the case where the number of threads N = 3 and the rotation angle θc of the rotating shaft in the compression stroke is 210 °.
Also in this case, the number n of working chambers formed at the same time is n = 1 or 2, and the maximum value of the number of working chambers formed at the same time is 2, which is smaller than the number of rows. In such a state, the working chamber is formed to be deviated around the rotation axis, so that a mechanical imbalance occurs, the rotation moment acting on the displacer becomes excessive, the contact load between the displacer and the cylinder increases, and There is a problem that performance is reduced due to an increase in friction loss and reliability is reduced due to wear of the vane.

In order to solve this problem, in the present embodiment, the rotation angle θc of the rotating shaft from the end of suction to the end of discharge (sometimes referred to as a compression stroke) is expressed as (((N−1) / N) · 360゜) <θc ≦ 360 ゜ (Formula 1) The outer contour of the displacer and the inner contour of the cylinder are formed. In other words, the above-mentioned winding angle is in the range of Expression 1.

Referring to FIG. 9B, the rotation angle θc of the rotating shaft in the compression stroke is larger than 270 °, and the number n of working chambers formed simultaneously is n = 3 or 4, and The maximum value of the number is four. This value is the number of articles N
(= 4).

In FIG. 10 (b), the rotation angle θc of the rotating shaft in the compression stroke is larger than 240 °, and the number n of working chambers formed simultaneously is n = 2 or 3, and The maximum number is 3. This value is the number of articles N
(= 3).

As described above, the rotation angle θc of the rotation shaft in the compression stroke
Since the maximum value of the number of working chambers becomes equal to or more than the number N of rows by making the lower limit value of the left side of Equation 1 larger than the value on the left side of Equation 1, the working chambers are dispersedly arranged around the rotation axis. In addition, the rotational balance acting on the displacer is reduced, the contact load between the displacer and the cylinder is reduced, and the reliability of the contact portion can be improved as well as the performance is improved by reducing the mechanical friction loss.

On the other hand, the upper limit of the rotation angle θc of the rotation shaft in the compression stroke is 360 ° according to the equation (1). The upper limit of the rotation angle θc of the rotation shaft in this compression stroke is 360 °. As described above, the time lag from the end of the discharge of the working fluid to the start of the next compression stroke (end of suction) can be made zero, and the gas in the gap volume occurring when θc <360 ° can be re-established. It is possible to prevent a reduction in suction efficiency due to expansion, and to prevent irreversible mixing loss that occurs when the two working chambers merge due to different pressure increases in the two working chambers when θc> 360 °. The latter will be described with reference to FIG.

FIG. 11 shows a positive displacement type fluid machine in which the compression stroke is 375 ° at the rotation angle θc of the rotating shaft. FIG. 11 (a)
5 shows a state in which the suction of the two working chambers 15a and 15b has been completed. At this time, the pressures of the two working chambers 15a and 15b are equal at the suction pressure Ps. The discharge port 8a is located between the working chambers 15a and 15b, and does not communicate with both working chambers. FIG. 11B shows a state in which the rotation has been advanced by 15 ° at the rotation angle θc of the rotation shaft from this state.
This is a state immediately before the discharge port 8a and both working chambers 15a and 15b communicate with each other. At this time, the volume of the working chamber 15a is as shown in FIG.
The compression is progressing smaller than at the end of the suction in (a), and the pressure is higher than the suction pressure Ps. On the other hand, the volume of the working chamber 15b is larger than that at the end of suction, and the pressure is also lower than the suction pressure Ps due to the expansion action. When the next instantaneous working chambers 15a and 15b are united (communicated), irreversible mixing as shown by an arrow in FIG. 11C occurs, and performance degradation due to an increase in compression power occurs. Therefore, the upper limit of the rotation angle θc of the rotation shaft in the compression stroke is desirably 360 °.

FIGS. 12A and 12B show a compression element of a positive displacement fluid machine described in Document 3 or 4, wherein FIG. 12A is a plan view and FIG. 12B is a side view. The number of threads N is 3, and the rotation angle θc (winding angle) of the rotating shaft in the compression stroke is 210 °. In this figure, the number n of working chambers is n = 1 or 2, as shown in FIG. This figure shows a state where the rotation angle θ of the rotating shaft is 0 °, and the number n of working chambers is two. As is apparent from this figure, the space on the right side of the space formed by the outer peripheral contour of the displacer and the inner peripheral contour of the cylinder does not become a working chamber, and the suction port 7a and the discharge port 8a communicate with each other. I have. Therefore, the discharge port 8a
The gas once flowing into the cylinder 4 from the suction port 7a flows backward due to the re-expansion of the gas in the gap volume, and the suction efficiency is reduced.

Now, let us consider a case where the rotation angle θc of the rotating shaft in the compression stroke of the positive displacement fluid machine shown in FIG. 12 is expanded by using the concept of the present embodiment. In order to increase the rotation angle θc of the rotation shaft in the compression stroke, the winding angle of the contour curve of the cylinder 4 must be increased as shown by a two-dot chain line. It is difficult to make the rotation angle θc of the rotation shaft of the compression stroke larger than 240 ° so that the thickness becomes thin and the maximum value of the number n of the working chambers becomes more than the number N of rows (N = 3).

FIG. 13 shows an embodiment of the compression element of the displacement type fluid machine having the same stroke volume (suction volume), the same outer diameter, and the same turning radius as the displacement type fluid machine shown in FIG. The rotation angle θc of the rotation shaft in the compression stroke of the compression element shown in FIG. 13 realizes 360 ° larger than 240 °. This is because, in the compression element shown in FIG. 12, the gap between the seal points forming the working chamber is formed by a smooth curve, and therefore, for example, the rotation of the rotation shaft during the compression stroke is performed based on the concept of the present embodiment. Although a maximum of 240 ° is the limit for increasing the angle θc, in the compression element according to the present embodiment shown in FIG. 13, the distance between the sealing points (ac) is not smooth (in the case of a uniform curve). However, the shape in the vicinity of the contact b is formed so as to protrude when viewed from the displacer, and a constriction exists in the middle of each strip of the displacer from the center to the tip. These are also applicable to the embodiment shown in FIG. With these shapes,
The winding angle from the contact a to the contact b is larger than 240 ° 3
60 °, and the winding angle from the contact point b to the contact point c can be 360 °, which is larger than 240 °.
As a result, the rotation angle θc of the rotating shaft in the compression stroke can be set to 360 ° which is larger than 240 °, and the maximum value of the number n of working chambers can be set to the number N or more. For this reason, the working chambers are dispersed and the rotation moment can be reduced.

Further, when the cylinder height (thickness) of the compression element shown in FIG. 12 is set to H due to the increase in the number of working chambers that can function effectively, the compression element shown in FIG. Since the cylinder height is 0.7H, which is 30% lower, the size of the compression element can be reduced.

FIG. 14 is an explanatory diagram of the load and moment acting on the displacer 5 in this embodiment.
The symbol θ is the rotation angle of the rotating shaft 6, and ε is the turning radius. With the compression of the working gas, a tangential force Ft perpendicular to the eccentric direction and a radial force Fr corresponding to the eccentric direction act on the displacer 5 due to the internal pressure of each working chamber 15 as shown in the figure. The resultant force of Ft and Fr is F. A rotational moment M that attempts to rotate the displacer due to the deviation of the resultant force F from the center o of the displacer 5 (arm length 1).
(= F · l) works. The reaction force R1 and the reaction force R2 at the contact points e and b of the displacer 5 and the cylinder 4 support the rotation moment M. In the present invention, moments are always received at two or three contact points near the suction port 7a, and no reaction force acts on the other contact points.

The displacement type compression element 1 of the present invention includes a crank part 6 a of a rotating shaft 6 fitted to the center of a displacer 5.
The working chambers in which the rotation angle of the rotating shaft from the end of suction to the end of discharge is substantially 360 ° at a substantially equal pitch are distributed and arranged, so that the point of action of the resultant force F is located at the center o of the displacer 5. Close to the moment of arm length l
Can be reduced to reduce the rotation moment M.
Therefore, the reaction force R1 and the reaction force R2 are reduced. Also,
As can be seen from the positions of the contact point g and the contact point b, the sliding portion between the displacer 5 and the cylinder 4 receiving the rotation moment M is located near the suction port 7a of the working gas having a low temperature and a high oil viscosity. It is possible to provide a highly reliable positive displacement fluid machine in which the oil film of the moving part is secured and the problem of friction and wear is solved.

FIG. 15 shows a comparison between the compression element shown in FIG. 12 and the compression element shown in FIG. 13 in terms of the rotation moment M acting on the displacer during one rotation of the shaft due to the internal pressure of the working fluid. The calculation conditions are the refrigerating conditions of the working fluid HFC134a (suction pressure Ps = 0.095 MPa, discharge pressure Pd = 1.43 MPa). Accordingly, in the compression element according to the present embodiment in which the maximum value of the number n of the working chambers is equal to or greater than the number of the working chambers, the working chambers from the end of the suction to the end of the discharge are dispersed around the rotation axis at a substantially equal pitch. It is possible to provide a structure in which the mechanical balance is improved and the load vector due to compression is substantially directed to the center. Therefore, the rotation moment M acting on the displacer can be reduced. As a result, the contact load between the displacer and the cylinder is reduced, so that the mechanical efficiency can be improved and the reliability as a compressor can be improved.

Here, the suction port 7a and the discharge port 8a
The relationship between the period in which is communicated and the rotation angle of the compression stroke rotation shaft will be described. The time lag Δθ represented by the rotation angle of the rotating shaft during the period in which the suction port and the discharge port communicate with each other, that is, from the end of the discharge of the working fluid to the start of the next compression stroke (end of suction) is the rotation axis of the compression stroke. As the rotation angle θc of
θ = 360 ° −θc. If Δθ ≦ 0 ゜,
Since there is no period in which the suction port and the discharge port communicate with each other, the suction efficiency does not decrease due to the re-expansion of the gas in the clearance volume of the discharge port. When Δθ> 0 °, since there is a period in which the suction port and the discharge port communicate with each other, the suction efficiency is reduced due to the re-expansion of the gas in the clearance volume of the discharge port, and the (refrigeration) capacity of the compressor is reduced. Will decrease. Further, a decrease in the suction efficiency (volume efficiency) leads to a decrease in the adiabatic efficiency, which is the energy efficiency of the compressor, or the coefficient of performance.

The rotation angle θc of the rotating shaft in the compression stroke is determined by the winding angle of the contour curve of the displacer or cylinder and the positions of the suction port and the discharge port. When the winding angle of the contour curve of the displacer or cylinder is set to 360 °, the rotation angle θc of the rotating shaft in the compression stroke is 36 °.
The angle can be set to 0 ° and θc <360 ° by moving the seal point of the suction port or the discharge port. However, θc> 360 ° cannot be achieved. For example, the rotation angle θc = 375 ° of the rotating shaft in the compression stroke of the compression element shown in FIG. 11 can be changed to θc = 360 ° by changing the position and size of the discharge port. This can be realized by increasing the discharge port so that the working chamber 15a and the working chamber 15b communicate with each other immediately after the suction end state in FIG. By performing such a change, it is possible to reduce irreversible mixing loss that occurs due to the difference in pressure rise between the two working chambers that occurred when θc = 375 °.
Therefore, it can be said that the winding angle of the contour curve is a necessary condition for determining the rotation angle θc of the rotating shaft in the compression stroke, but is not a sufficient condition.

The embodiment described above, that is, FIG.
In the embodiment shown in (1), the closed type compressor in which the pressure in the closed casing 3 is maintained at a low pressure (suction pressure) has been described. However, the use of the low pressure type has the following advantages. (1) Since the heating of the electric element 2 by the compressed high-temperature working gas is small and the electric element 2 is cooled by the suction gas, the temperatures of the stator 2a and the rotor 2b are reduced, and the motor efficiency is improved to improve the performance. be able to. (2) In a working fluid compatible with the lubricating oil 12 such as Freon, the pressure is low, so that the proportion of the working gas dissolved in the lubricating oil 12 is reduced, so that the oil bubbling phenomenon in bearings and the like is less likely to occur, and the reliability is improved. Performance can be improved. (3) The pressure resistance of the sealed container 3 can be reduced, and the thickness and weight can be reduced.

Next, a type in which the pressure in the sealed container 3 is maintained at a high pressure (discharge pressure) will be described. FIG.
FIG. 6 is an enlarged cross-sectional view of a main part of a high-pressure hermetic compressor using a swirling fluid machine according to another embodiment of the present invention as a compressor. In FIG. 16, components denoted by the same reference numerals as those in FIGS. 1 to 3 are the same components and perform the same operations. In the drawing, reference numeral 7b denotes a suction chamber formed integrally with the main bearing 7 by a suction cover 10, which is separated from the pressure (discharge pressure) in the sealed container 3 by a seal member 16 or the like. Reference numeral 17 denotes a discharge passage communicating between the inside of the discharge chamber 8b and the closed container 3. The operation principle and the like of the positive displacement compression element 1 are the same as those of the low pressure (suction pressure) type described above.

The flow of the working gas is indicated by an arrow in the drawing, and the working gas that has entered the suction chamber 7b through the suction pipe 13 passes through a suction port 7a formed in the main bearing 7 and is displaced by the positive displacement element. 1, where the rotation of the rotating shaft 6 causes the displacer 5 to make a revolving motion, and the volume of the working chamber 15 is reduced, thereby being compressed. The compressed working gas pushes up the discharge valve 9 through the discharge port 8a formed in the end plate of the sub bearing 8 to enter the discharge chamber 8b, and the discharge passage 1
7, the air enters the closed container 3, and flows out from a discharge pipe (not shown) connected to the closed container 3. The advantage of such a high-pressure type is that the lubricating oil 12 is at a high pressure, so that the lubricating oil 12 supplied to each bearing sliding portion by the centrifugal pump action or the like due to the rotation of the rotary shaft 6 has a gap between the end faces of the displacer 5. And the like, it is easy to be supplied into the cylinder 4 through the like, and thus the sealing property of the working chamber 15 and the lubrication property of the sliding portion can be improved.

As described above, in the compressor using the positive displacement fluid machine of the present invention, it is possible to select either the low-pressure type or the high-pressure type according to the specifications and use of the equipment, the production equipment, etc., and the degree of freedom in design is greatly increased. To expand.

Next, a method of manufacturing the displacer according to the embodiment of the present invention, particularly, a method of finishing the outer peripheral contour having a unique shape will be described. FIG. 17 is an explanatory diagram of this.
FIG. 18 is a cross-sectional view of the outer peripheral processing state of the displacer. In the figure, reference numeral 18 denotes a processing jig comprising a base 18a, a plurality of pins 18b fixed to the base 18a, and a clamp 18c for fixing a workpiece. Reference numeral 19 denotes a processing tool, which includes a grinding tool 19a, a cutting tool 19b, and the like. The raw material of the displacer 5 made by casting, forging, or the like is first processed at both end faces, and the positioning through hole 5b and the bearing 5a are precisely positioned.

Next, as shown in FIG.
Is fitted along the pin portion 18b of the processing jig 18 and is fixed to the base 18a by a clamp 18c with a screw or mechanical force. This mounting state (Fig. 1
In 8), using a machining center or the like, a grinding tool 19 is used.
a, finishing processing of the outer peripheral contour is performed by the cutting tool 19b and the like. Thus, a plurality of through holes 5b are formed around the bearing 5a at the center of the displacer 5, and the through holes 5b are formed.
Since “b” is used as a positioning reference for attachment to the processing jig 18, accurate positioning is possible, and deformation or the like during cutting / grinding is prevented, so that the dimensional accuracy of the contour shape can be improved. In addition, since the through holes are shared with the assembly and positioning of the inspection jig, the assembling and inspection operations can be performed efficiently. Furthermore, it contributes to the weight reduction of the displacer 5. On the other hand, the processing of the inner peripheral contour of the cylinder 4 is performed by fixing the outer periphery of the cylinder 4 to a mounting jig and using a machining center or the like. In order to increase the rigidity of the vane 4b of the cylinder 4, the cylinder 4 may be fixed to the end plate surface of the main bearing 7, or the cylinder 4 and the main bearing 7 may be integrally formed.

FIG. 19 is an explanatory view showing the structure of the discharge valve 9 provided at the outlet of the discharge port 8a of the auxiliary bearing 8. A concave portion 82 is formed on the outlet side of the discharge port 8a of the auxiliary bearing 8, and a valve seat 84 of the discharge port 8a is formed in the concave portion 82. Discharge valve 9 arranged opposite to valve seat 84
Is constituted by a valve plate 90 and a retainer 100.

FIG. 20 is a plan view of the valve plate 90. The valve plate 90 is formed of a single plate having a hole 91 at the center thereof for fitting into the boss of the sub bearing 8.
The valve plate 90 has a number of arms 92 facing the discharge ports of the positive displacement fluid machine. That is, in this embodiment, three arms 92 are provided. The valve plate 90 is formed by stamping a highly elastic plate material such as flapper valve steel (steel strip for a valve plate). Therefore, the arm 92 has elasticity. A valve portion 94 is formed at the distal end of the arm 92. The valve portion 94 is separated from and brought into contact with the valve seat 84 of the discharge port 8a.
The discharge port 8a is opened and closed. Valve plate 9
0 has three through holes 96, and the valve plate 90 is fixed to the auxiliary bearing 8 using the through holes 96.

FIG. 21 is a plan view and a front view of the retainer 100. Retainer 100 has a planar shape that approximates the planar shape of valve seat 90. A central portion has a hole 101 to be fitted to the boss of the auxiliary bearing 8, and includes three arms 102 corresponding to the arms of the valve seat 90. The tip of the arm 102 is connected to the stopper 104 bent at a predetermined angle via the bent portion 103. The retainer 100 has three through holes 106 and is fixed to the sub bearing 8 with bolts or the like in phase with the through hole 96 of the valve plate 90.

As shown in FIG. 19, the valve plate 90
When the retainer 100 and the retainer 100 are fixed to the sub bearing 8, the valve portion 94 of the valve plate 90 contacts the valve seat 84 of the discharge port 8a, and the stopper portion 104 of the retainer 100
4 is positioned at a distance H away from H.4. That is, the stopper portion 104 of the retainer 100 has a function of defining the lift amount of the valve portion 94 of the valve plate 90.

FIG. 22 is a plan view showing the positional relationship of the discharge valve 9 with respect to the protrusion 4b of the cylinder 4 and the discharge port 8a.

FIG. 23 shows the bearing surface 8 formed on the sub bearing 8.
1, the discharge port 8a, the recess 8
FIG. 2 is a cross-sectional view illustrating a relationship between a discharge passage 17 and the like.

FIG. 24 shows a discharge port 8a provided in the sub bearing, a bolt hole 86 for mounting the discharge valve 9, a discharge passage 17, and a bolt hole 8d for fixing the sub bearing together with the cylinder end plate to the main bearing. FIG. 25 is a plan view showing the arrangement.
FIG. 25 is a sectional view taken along line BB of FIG. 24.

[0068]

As described above, according to the present invention, the displacer and the cylinder are arranged between the end plates, and when the center of the cylinder is aligned with the center of the displacer, the inner wall surface of the cylinder and the outer wall surface of the displacer are arranged. An end plate having a suction port and an end plate having a discharge port in a displacement type fluid machine in which a single space is formed and a plurality of spaces are formed when a positional relationship between the displacer and the cylinder is set at a turning position. And a cylinder containing a flat displacer disposed between both end plates,
A plurality of discharge valves disposed on the outlet side of the discharge port, the valve including a rotary shaft having a crank portion disposed at a substantially central portion of the cylinder, and a plurality of discharge valves disposed on the valve plate; Of the retainer. With this configuration, a plurality of discharge valves can be easily manufactured, and a positive displacement fluid machine that can be easily assembled and adjusted can be received.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view and a plan view of a compression element of a hermetic compressor in which a positive displacement fluid machine according to the present invention is applied to a compressor.

FIG. 2 is an explanatory view of the operation principle of the positive displacement fluid machine according to the present invention.

FIG. 3 is a longitudinal sectional view of a positive displacement fluid machine according to the present invention.

FIG. 4 is a diagram showing a contour configuration method of a displacer of the positive displacement fluid machine according to the present invention.

FIG. 5 is a diagram showing a method of forming a contour of a cylinder of the positive displacement fluid machine according to the present invention.

FIG. 6 is a diagram in which the displacer and the cylinder shown in FIGS. 4 and 5 are superimposed.

FIG. 7 is a diagram showing a volume change characteristic of a working chamber in the present invention.

FIG. 8 is a graph showing a change in gas compression torque according to the present invention.

FIG. 9 is a diagram showing a relationship between a rotation angle of a rotation shaft and a working chamber in a four-row wrap.

FIG. 10 is a diagram showing a relationship between a rotation angle of a rotation shaft and a working chamber in the three-row wrap.

FIG. 11 is an operation explanatory diagram when the winding angle of the compression element is larger than 360 °.

FIG. 12 is a view for explaining an enlargement of a winding angle of a compression element.

FIG. 13 is a modified example of the positive displacement fluid machine shown in FIG. 1;

FIG. 14 is a diagram illustrating loads and moments acting on the displacer of the present invention.

FIG. 15 is a diagram showing a relationship between a rotation angle of a rotation shaft of a compression element and a rotation moment ratio.

FIG. 16 is a vertical sectional view of a main part of a hermetic compressor according to another embodiment of the present invention.

FIG. 17 is an explanatory diagram of the outer peripheral contour processing of the displacer according to the present invention.

FIG. 18 is a sectional view showing a state in which a processing jig of the displacer according to the present invention is attached.

FIG. 19 is an enlarged sectional view of a discharge valve.

FIG. 20 is a plan view of a valve plate.

FIG. 21 is a plan view and a front view of a retainer.

FIG. 22 is a plan view showing a positional relationship between a discharge port and a discharge valve.

FIG. 23 is a sectional view of the auxiliary bearing 8;

FIG. 24 is a plan view showing the arrangement of a discharge port, a discharge valve, and the like.

FIG. 25 is a sectional view taken along line BB of FIG. 24;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Displacement type compression element 2 Electric element 3 Airtight container 4 Cylinder 4a Inner peripheral wall 4b Vane 4c Bolt hole 5 Displacer 5a Slewing bearing 5b Through hole 6 Rotation shaft 8 Secondary bearing 8a Discharge port 9 Discharge valve 82 Recess 84 Valve seat 90 Valve plate 92 Arm 94 Valve 100 Retainer 102 Arm 104 Stopper

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Kazuo Sekigami 800 Futami Tomita, Ohira-cho, Shimotsuga-gun, Tochigi Prefecture Inside the Hitachi, Ltd.Cooling Division (72) Inventor Kenji Tojo 390 Muramatsu, Shimizu-shi, Shizuoka Prefecture Inside Air Conditioning Systems Division, Hitachi, Ltd.

Claims (4)

[Claims] 1. A displacer and a cylinder are disposed between end plates, and when the cylinder center and the displacer center are aligned, one space is formed by the cylinder inner wall surface and the displacer outer wall surface, and the displacer and the cylinder are formed. In a positive displacement fluid machine in which a plurality of spaces are formed when the positional relationship between the end plate having a plurality of spaces is formed, an end plate having a suction port and an end plate having a discharge port, and a flat displacer disposed between the both end plates are provided. And a rotary shaft having a crank portion disposed substantially at the center of the cylinder, and a discharge valve that opens and closes with a differential pressure of a fluid is provided on the outlet side of the discharge port. Fluid machine. 2. A displacer and a cylinder are arranged between end plates, and when the cylinder center and the displacer center are aligned, one space is formed by the cylinder inner wall surface and the displacer outer wall surface, and the displacer and the cylinder are formed. In a positive displacement fluid machine in which a plurality of spaces are formed when the positional relationship between the end plate having a plurality of spaces is formed, an end plate having a suction port and an end plate having a discharge port, and a flat displacer disposed between the both end plates are provided. And a rotary shaft having a crank portion disposed substantially at the center of the cylinder, and a discharge valve that opens and closes with a differential pressure of fluid at the outlet side of the discharge port. A positive displacement fluid comprising: a plate-shaped valve portion that comes into contact with a valve seat formed on an outlet side of an outlet, and a stopper portion that sets a lift amount of the valve portion. machine. 3. A displacer and a cylinder are disposed between end plates, and when the cylinder center and the displacer center are aligned, one space is formed by the cylinder inner wall surface and the displacer outer wall surface, and the displacer and the cylinder are formed. In a positive displacement fluid machine in which a plurality of spaces are formed when the positional relationship between the end plate having a plurality of spaces is formed, an end plate having a suction port and an end plate having a discharge port, and a flat displacer disposed between the both end plates are provided. And a rotary shaft having a crank portion disposed substantially at the center of the cylinder, and a discharge valve that opens and closes with a differential pressure of fluid at the outlet side of the discharge port. It has a plate-shaped valve portion that comes into contact with and separates from a valve seat formed on the outlet side of the outlet, and a stopper portion that sets the lift amount of the valve portion. A positive displacement fluid machine characterized in that a plurality of discharge ports are formed in a lube plate and a stopper portion is formed in one retainer laminated on the valve plate. 4. The displacement type fluid machine according to claim 3, wherein the valve plate and the retainer are fixed to the end plate by a fixing tool inserted into a hole passing through both.