JPS60175791A - Rolling piston type rotary fluid machine - Google Patents

Abstract

PURPOSE:To produce a compact fluid machine by containing an arc type rolling vane contacting hermetically with an eccentric rolling piston in a vane chamber thereby reducing the frictional loss caused through the differential pressure between suction and delivery pressures. CONSTITUTION:An eccentric shaft 36 is fitted at the rear end of an input shaft 34 while a rolling piston 46 is mounted rotatably through an eccentric pin 38. Vane chamber 54 is axial parallel with the cylinder bore 14 and containing an arc type rolling vane 58. The rolling vane 58 is supported rollably in the vane chamber to enable angular displacement in the direction to approach/depart from the operating chamber while following the displacement of rolling piston.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a rolling piston type rotary fluid machine used as a paccum pump, an air pump, a compressor, an oil pump, etc. This invention relates to an improvement in a partition mechanism, that is, a vane mechanism, which partitions a suction chamber, a discharge chamber, etc.

"Prior art" A rolling piston with a cylindrical outer circumferential surface rolls within a cylindrical cylinder bore formed in a housing, and this rolling piston cooperates with a vane that partitions the working chamber into a suction chamber and a discharge chamber. 2. Description of the Related Art A rolling piston type rotary fluid machine that sucks in and discharges fluid sound is known. In this conventional rolling piston type rotary fluid machine, the vane that partitions the working chamber into a discharge chamber and a suction chamber is a flat plate, and the vane is housed in a guide slot formed in the housing of the fluid machine. The piston is slid against the piston so as to follow the rolling piston by the force of the spring. During operation of this fluid machine, a load due to the pressure difference between suction pressure and discharge pressure acts on the vane, so the frictional force applied to the sliding part between the guide slot and the vane is constant. Friction loss increases. especially,
When this fluid machine is driven by an electric motor, the load torque of the motor increases, resulting in a decrease in rotational speed, leading to a decrease in pump performance of the fluid machine. Furthermore, since the housing must be enlarged to accommodate the springs and vanes, there is also the disadvantage that the overall size of the fluid machine increases.

``Object of the Invention'' The present invention was devised in view of the problem of constriction in the prior art, and provides a fluid machine that reduces friction loss due to the pressure difference between suction pressure and discharge pressure, and provides a continuous fluid machine. The purpose is to

"Structure of the Invention" The gist of the present invention is to achieve the above object by providing a rotatable structure to a vane that slides into sliding contact with a rolling piston and partitions a working chamber into a suction chamber and a discharge chamber.

In the simplest embodiment of the present invention, the housing of this fluid machine has a vane chamber formed of a cylindrical bore parallel to the cylinder bore and adjacent to the cylinder over the entire length of the cylinder bore. The axis of the cylindrical bore of this vane chamber is located outside the cylindrical surface of the cylinder pore. Further, the cylindrical bore forming the vane chamber intersects with the outer peripheral surface of the rolling piston at the lowest position.

An arc-shaped swinging vane is housed coaxially in the vane chamber of the vane, and is rotatably supported by the housing. This arc-shaped oscillating vane has a sealing edge that slides over its entire length on the rolling piston, and a partially cylindrical outer peripheral wall that has an outer diameter slightly smaller than the radius of the vane chamber and extends over the entire length of the vane chamber. It is equipped with This partially cylindrical outer circumferential wall extends circumferentially over an angular range such that it forms a sufficient sealing area with the vane chamber circumferential wall at the lowest position of the rolling piston.

This arc type swinging vane is biased toward the rolling piston by a biasing means such as a linear cylinder, and its sealing edge comes into sliding contact with the rolling piston.

Because of this configuration, the load due to the pressure difference generated between the suction chamber and the discharge chamber during operation of the fluid machine acts in the normal direction to the partially cylindrical outer circumferential wall of the arc-type swinging vane. Therefore, it acts radially inward toward the rotation axis of the swing vane. Since the rotating shaft of the swing vane is rotatably supported by the housing, the frictional force between the swing vane and the vane chamber does not increase due to the pressure difference. Therefore, the friction loss of this fluid machine can be minimized. In addition, in conventional rolling piston type rotary fluid machines, the flat vanes were displaced linearly following the displacement of the rolling piston, but with the structure of the present invention, arc type oscillating vanes are used. is displaced in the rotation angle direction according to the displacement of the rolling piston, so
The size of the fluid machine will also be 9 parts.

In a preferred embodiment of the present invention, the inner diameter of the inner circumferential wall of the vane chamber and the outer diameter of the outer circumferential wall of the swinging vane are such that the swinging vane does not substantially contact the circumferential wall of the vane chamber; A sealing gap of a very small distance is formed between the swing vane and the outer circumferential wall of the swing vane.

With such dimensions, the mechanical frictional resistance between the swinging vane and the circumferential wall of the vane chamber becomes substantially zero. Therefore, friction losses in the fluid machine are minimized. however,
Since the sealing gap between the circumferential wall of the vane chamber and the outer circumferential wall of the swinging vane is an extremely small force distance, the loss of fluid flowing through the sealing gear horn is substantially negligible. The seal between the vane chamber and the swinging vane is thus maintained substantially well.

Preferably, the biasing means comprises a mainspring or torsion coil spring fixed at one end to the housing and at the other end to the swing vane, the preload of which is such that when the rolling piston is in its lowest position, It is set so that the spring load is substantially zero and is maximum when it is in the uppermost position. If the spring preload is set in this way, the swinging vane will not receive any spring load at the lowest position of the rolling piston, and only the rotational inertia of the swinging vane will act on the sealing edge of the swinging vane. ing. This inertial force is sufficient to seal between the sealing edge and the rolling piston. Therefore, sealing performance can be ensured while minimizing the frictional force between the sealing edge and the rolling piston.

In a preferred embodiment, the outer periphery of the rolling piston is provided with a layer of elastic material. This layer of elastic material acts to buffer the impact when the rolling piston rolls on the cylinder deck, and also slides on the oscillating vane as the rolling piston rotates while rolling from its lowest position to its highest position. This serves to facilitate the upward retreat of the swinging vane.

Preferably, side plates are provided at both axial ends of the swinging vane, and arcuate grooves are provided on the outer surfaces of these side plates. An arcuate sealing member axially outwardly biased by a spring is fitted into this groove. In this way, the side seals at both axial ends of the swing vane become more reliable.

Furthermore, a partially cylindrical notch is provided in the partially cylindrical outer peripheral wall of the swing vane, and a partially cylindrical sealing member radially outwardly biased by a spring is fitted into the notch. This configuration ensures a radial seal between the vane chamber and the swinging vane.

In another preferred embodiment of the invention, the spring for biasing the swinging vane is arranged inside the swinging vane. With such a configuration, the length of the nozzle in the axial direction can be reduced, and the fluid 'fM rod can be made compact.

Other features and effects of the present invention will become clearer as the embodiments of the present invention are described with reference to the accompanying drawings. An example is shown below. This compressor 10 includes a housing 12. The housing 12 includes a cylinder 16 in which a cylindrical cylinder bore 14 is formed, a front side plate 18, a rear side plate 20. and m=. A cover 22 is arranged in front of the front side plate 18.
The cylinder 16, the front plate 18, the rear plate 20, and the cover 22 are integrally connected to each other by four through delts 30 with O-rings 24, 26, and 28 interposed therebetween. An input shaft 34 is rotatably supported on the cover 22 by a υ bearing 32 that includes rollers such as ball bearings. An eccentric shaft 36 is fitted to the rear end of the input shaft 34 with a yaw stop or a line so that the input shaft 34 and the eccentric shaft 36 can rotate together. An l-center pin 38 and a balance weight 40 are integrally formed on the eccentric shaft 36. As can be seen from FIG. 1, the axial center of the eccentric bin 38 is offset from the axial center of the input shaft 34 by an eccentric amount ρ. Therefore, the axis of the eccentric bin 38 rotates in a circle 42 having a radius ρ, as shown in FIG. The balance weight 40 can be shaped like a fan and can be removably attached to the eccentric shaft 36, as in the prior art.

A rolling piston 46 is rotatably mounted on the eccentric bin 38 via a rolling bearing 44 such as a ball bearing. As can be seen from FIG. 2, the rolling piston 46 has a cylindrical outer circumferential surface 48 as in the prior art.

The rolling piston 46 is provided with a layer 50 of an elastic material such as rubber on the outside thereof. This elastic material layer 50 has the function of buffering the impact when the rolling piston 46 moves on the inner circumferential wall of the cylinder 714, and also has the function of facilitating the retreat of the swinging vane, which will be described later. It is also possible not to provide this elastic material layer 50, but in that case, the clearance between the outer circumferential surface of the rolling piston 46 and the inner circumferential wall of the cylinder 714 is a non-lubricated console.

10 to 20μm in case of servo, 40μm in case of oil supply type
It is preferable to set the thickness to 60 μm. The clearance between both axial end surfaces of the rolling piston 46 and the front and rear side plates 18.degree. 20 is preferably 10 to 20 .mu.m in the case of a non-lubricated piston, and 40 to 60 .mu.m in the case of a lubricated piston. As the input shaft 34 rotates, the rolling piston 46 rolls on the inner circumferential surface of the cylinder arm 14, and rotates around its axis.

A cylindrical shape 752 is formed in the cylinder 16 adjacent to the cylinder gear 14 and directly above the cylinder 714, and this cylindrical shape? A 52 constitutes a vane chamber 54.

As can be seen from FIG. 2, the vane chamber 54 has a cylinder 71.
4, its axis 0 is parallel to cylinder bore 14
It is located outside the cylindrical surface of. Further, although FIG. 2 shows the rolling piston 46 at its lowest position, the cylindrical bore 52 is positioned to intersect with the outer peripheral surface of the rolling piston 46 at its lowest position. There is. Therefore, the working chamber 56 whose cylinder is formed by A 14 and the vane chamber 54 whose cylindrical shape is formed by A 52 communicate with each other.

An arc-shaped swinging vane 58 is housed coaxially within the vane chamber 54, and the swinging vane 58 follows the displacement of the rolling piston 46 toward the working chamber 56 or towards the working chamber 56. It extends in such a way that it can be angularly displaced in the direction of moving away from the object. In the illustrated embodiment, this swinging vane 5
8 consists of a substantially cylindrical outer circumferential wall 60 and side walls 62 and 64 integrally formed at both axial ends of the outer circumferential wall 6o.

A vane shaft 66 is press-fitted into the center of this swinging vane 58, and this vane shaft 66 is rotatably supported by the front and rear side plates 18 and 2o by rolling wheel bearings 68 and 7 degrees such as pole bearings. . As can be seen from FIG. 2, the outer circumferential surface of the outer circumferential wall 60 of the swing page 758 is approximately semi-cylindrical, and the outer diameter of the outer circumferential wall 60 is slightly smaller than the inner diameter of the cylindrical pore 52. This allows the swinging vane 58 to rotate freely without substantially contacting the cylindrical diameter 52. However, the distance between the cylindrical shape 52 and the outer peripheral surface of the swing vane must be determined such that a sealing gap of a sufficiently small distance is formed therebetween. If this compressor is an oil-free type, this sealing gear horn should be 10 to 20 μm.
It is preferable to set it to m, and in the case of an oil supply type, it is 40 to 60 μm.
It is preferable to set it to m. The extent of the outer circumferential wall 60 of the swinging vane 58 in the rotation angle direction does not necessarily have to be semicircular as shown in FIG. If a sufficient sealing area is formed between the swinging vane 58 and the outer circumferential wall 60, it may be fan-shaped with an angle of up to 180°. In the embodiment shown in FIG. 2, from point X to point y'!
1. The arcuate region between and forms the sealing region when the piston 46 is in its lowest position. The clearance between the side walls 62 and 64 of the swinging vane 58 and the side plates 18 and 20 of the housing is 10 to 10 in the case of an oil-free compressor.
It is preferably 20 μm, and 40 to 60 μm in the case of an oil supply type.

A sealing edge 72 is provided at the leading end of the swing vane 58.
is formed. In the embodiment of FIG. 2, this sealing edge 72 has a slightly semicircular cross-sectional shape. This sealing edge 72 is always in line contact with the outer peripheral surface of the rolling piston 46, as will be described later with reference to FIG.

The radii of the cylindrical dea 52 and the swinging vane 58 and the positions of their axes are such that when the rolling piston 46 descends to its lowest position, the virtual outer circumferential surface of the swinging vane 58 and the outer circumferential surface of the piston 46 are 1 to 1. The piston 46 intersects the vane shaft 66 and the side wall 62.6 over a distance of 2 mm and when the piston 46 is raised to its uppermost position.
It must be set so that it does not come into contact with the knob portion 74 of No. 4.

As can be seen from FIG. 1, the swinging vane 58 has a structure in which the central portion is hollowed out to an extent that no problem arises in terms of strength in order to reduce the weight.

The swing vane 58 is made of a material with low density, such as carbon, resin, aluminum, or the like.

A disc-shaped notch is provided in the front side plate 18 of the housing, and a thinly wound spring 76 is accommodated in this notch. The inner end of this spiral winding 76 is connected to the vane shaft 6.
6, and its outer end is fixed to a knock pin 78 fixed to the front plate 18. This spiral spring 76 urges the swinging vane 58'lf to rotate counterclockwise in Figure 2.

The preload of the spiral spring cup 76 is the rolling piston 4.
6 reaches the lowest position (the position shown in FIG. 2), it is set so that almost no rotational biasing force acts on the swinging page 758. Therefore, when the piston 46 reaches the lowest position, the swing vane 58 is almost in a free state, and the sealing edge 72 of the swing vane 58 comes into contact with the rolling piston 46 due to its own rotational inertia. .

By setting the preload of the spiral spring 76 in this manner, it is possible to minimize the frictional force between the swing page 758 and the rolling piston 46. Nausu coiled spring 76
A torsion coil spring or the like may be used instead.

Next, the operation of the fluid machine of the present invention will be explained with reference to FIG. Fig. 3(a) shows when the rolling piston 46 is at the highest level, Fig. 3(6) shows when the piston 46 has rotated 90° clockwise, and Fig. 3(c) shows when the piston 46 is at the lowest position. position, and FIG. 3(d) shows the respective positions of the oscillating vanes 58 when the piston 46 has made an additional 900 revolutions.

In the position shown in Fig. 3 (,), air is sucked into the working chamber 56 through the suction port 80, and the volume of the working chamber 56 is at its maximum, and the maximum amount of air is sucked into the working chamber 56. There is. In this state, the maximum rotational biasing force is stored in the spring 76 (FIG. 1) and the sealing edge 72 of the swing vane 58 is in contact with the piston 46 at point A.

Next, when the input shaft 34 (Fig. 1) rotates 90 degrees, the third
In the position shown in Figure (b), the working chamber 56 is divided into a discharge chamber 82 and a suction chamber 84. In this position, air is being sucked into the suction chamber 84 from the suction port 80, while the volume of the discharge chamber 82 is reduced and air is being discharged from the discharge port 86.

Sealing edge 72 of swing vane 58 and piston 46
The contact point with the sealing edge 72 has moved to point B.
The restoring force of the spring 76 urges the spring 76 to rotate counterclockwise, ensuring contact with the piston. piston 4
6 and the cylinder pore 14 are in line contact at position E. The blow-through of compressed air from the discharge chamber 82 to the suction chamber 84 is at point B.

The sealing gap between the inner circumferential surface of the 8-point 2-cylindrical shape 752 and the outer circumferential surface of the swinging vane, as well as the swinging vane 58
This occurs in the gaps between both end surfaces of the side plates 18 and 2o, but since each gap is very small, blow-through does not actually pose a problem.

In the position shown in FIG. 3(,), the piston 46 has rotated to the lowest position, and the suction chamber 84 and the discharge chamber 82 have approximately the same volume. Compared to the state shown in FIG. 3(b), more air is being sucked into the suction chamber 84 through the suction port 8o, and the discharge chamber 82 is further reduced in size and air is being discharged through the discharge port 86. Sealing edge 72 and piston 4
6 has moved to point 0, and the point of contact between piston 46 and cylinder bore 14 has moved to point F.

In the position shown in FIG. 3(C), the stored force of the spring 76 is almost released, and the swing vane 58 is almost in a free state. Therefore, the swing vane 58 rotates counterclockwise from the state shown in FIG. 3(b) due to the restoring force of the spring 76, and the seal at the seal point C is ensured by its own rotational inertia force. The pressure difference generated between the discharge chamber 82 and the suction chamber 84 acts in the normal direction to the cylindrical outer circumferential surface of the outer circumferential wall 60 of the swing vane 58 . That is, the force due to the pressure difference acts toward the axis of the vane shaft 66. Since this vane shaft 66 is supported by rolling bearings 68 and 70, and since a small gap is ensured between the cylindrical dea 52 and the swinging vane 58, the above pressure difference is Even if it increases to 758
Frictional force is almost never generated. This point is significantly different from that in conventional fluid machines using flat vanes, in which the sliding friction of the flat vanes 6 increases due to the pressure difference between the discharge chamber and the suction chamber.

In the position shown in FIG. 3(a), the suction chamber 82 has further expanded, and the discharge chamber 82 has further contracted.◎The sealing point between the swinging vane 58 and the piston 46 has moved to point D. The sealing point between the piston 46 and the cylinder A 14 has moved to the G position. As the piston 46 moves from the state shown in FIG. 3(c) to the state shown in FIG. 3(d), the piston 46 pushes up the swinging vane 58 clockwise.

Therefore, restoring force is stored in the thinly wound spring 76. When the swinging vane 58 retreats clockwise while being pushed up by the piston 46 in this manner, the layer 5o of elastic material provided on the surface of the piston 46 plays a special role. That is, as the piston 46 rotates clockwise on the inner peripheral surface of the cylinder 714, the piston 46 rotates counterclockwise. A clockwise rotational force acts on the swinging bay 758 due to the frictional force. Therefore, the swinging vane 58 can easily retreat clockwise. In this embodiment, the layer of elastic material is provided on the outer circumferential surface of the piston 46, but it goes without saying that the same effect can be obtained even if the cylinder is placed on the inner surface of the piston 714.

4 and 5 show a second embodiment of the present invention.

Components common to the embodiment shown in FIGS. 1 and 2 are designated by the same reference numerals, and their description will be omitted. The feature of this second embodiment is that the vane shaft and the thinly wound spring of the swinging vane are arranged inside the swinging vane. That is, the vane shirt 90 of the swinging vane 58 is 1. t
A support portion 9 extends radially from the cylinder 16 toward the axis of the vane chamber 54 via a wheel bearing 92.
It is rotatably supported by 4. Spiral spring 9
6 is accommodated in the inner space of the swing vane 58, one end of which is fixed to the vane shaft 90, and the other end is fixed to the support portion 94. In the first embodiment, the spiral spring 76 and the bearings 68 and 70 of the vane shaft 66 are connected to the side plates 18 and 20 outside the vane chamber 54.
However, according to the second embodiment, the side plates 18 and 20 are made thinner and the axial length of the fluid machine 10 is increased. There is an advantage that the axial dimension of the fluid machine 10 can be made smaller.

6 to 8 show modified examples of the swinging vane. Side walls 62 and 64 of the swinging vane 58 have arc-shaped grooves 9, respectively.
A sealing member 100 of a circular arc A is fitted into this groove 98 via a wave washer (not shown). This seal member 100 is made of resin or other material with good sliding properties. The gap between the seal member 100 and the groove 98 is preferably 10 to 20 μm to allow the seal member 100 to move freely within the groove 98. Since the sealing member 100 is pressed against the side plates 18 and 20 by the spring force of the wave washer in this manner, fluid leakage from both end faces of the swing vane 58 is reduced and pump performance is improved.

9 to 12 show still other modifications of the swinging vane. As shown in FIGS. 9 and 10, the swinging vane 58
A partially cylindrical notch 102 is provided on the outer periphery of the housing, and a sealing member 104 as shown in FIGS. 11 and 12 is fitted into this notch 102 via a spring (not shown). has been done.

This sealing member 104 eliminates a radial gap between the hammer vane 58 and the vane chamber cylindrical bore 52. Therefore, the outer circumferential wall 6 of the cylindrical dea 52 and the swinging vane 58
Fluid is more completely prevented from blowing through the gap between the pump and the pump, improving pump performance.

"Effects of the Invention" The effects of the present invention have been explained in detail above, but to reiterate the most important effect here, it is that friction loss due to the pressure difference between the discharge pressure and the suction pressure is significantly reduced. This also means that the dimensions of the fluid machine will be large or small.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of the M1 embodiment of the rolling piston type rotary fluid machine of the present invention, Fig. 2 is a sectional view taken along the line ■-■ in Fig. 1, and Fig. 3 is a longitudinal sectional view of the M1 embodiment of the rolling piston type rotary fluid machine of the present invention. Fig. 4 shows the position of the rolling piston and the swinging vane in Fig. 4.
The figure is a longitudinal sectional view of a fluid machine according to a second embodiment of the present invention, FIG. 5 is a sectional view taken along the line ■-V in FIG. 4, and FIG. Fig. 7 is a sectional view taken along the arrow ■-■ in Fig. 6, Fig. 8 is a plan view of the arcuate seal member, and Fig. 9 is a cross-sectional view of the arc-shaped seal member.
10 is a sectional view of yet another modification of the swinging vane, FIG. 11 is an end view of a semi-cylindrical seal member, and FIG. 12 is a sectional view taken from the -■ arrow in FIG. 10 is a sectional view taken in the direction of Kariya. 10...Rolling piston type rotary fluid machine (compressor), 12...Housing, 14...Cylinder there, 16...Cylinder, 18...Front side plate ,2
0... Rear side plate, 22... Cover, 24, 25,
26...0 ring, 30...ruto through, 32...
・Rolling bearing, 34... Input shaft, 36... Eccentric shaft, 38... Eccentric bottle, 40... Balance weight, 42... Circle, 44... Rolling bearing, 46...
...Rolling piston, 48...Outer circumferential surface, 50...
- Elastic material layer, 52... Cylindrical bore, 54... Vane chamber, 56... Working chamber, 58... Swinging vane, 60...
...Outer peripheral wall, 62.64...Side wall, 66...Vane shaft, 68.70...Rolling bearing, 72...
Sealing edge, 74...Hub part, 76...Thin coil spring, 78...Knock bottle, 80...Suction port, 82...Discharge chamber, 84...Suction chamber, 86...Discharge Outlet, 90... Vane shaft, 92... Pole bearing, 94... Support part, 96... Spring, 98...
...Groove, 100...Sealing member, 102...Notch, 104...Sealing member O Patent applicant: Japan Auto Parts Research Institute Co., Ltd. Patent application representative Patent attorney Akira Aoki Patent attorney Kazu Nishidate Patent Attorney Hiroshi Ito Patent Attorney Akira Yamaguchi Patent Attorney Masaya Nishiyama (27) Total 3 days ((1) (b) (C) (d) Figure 4 Figure 5 To 1 Figure 6 1-Vll = hiVl 甐8E 'Setting 9: ?': tofuX - ㅅ 11 ・' -Xl1 -xn 1g-12gon

Claims (1)

[Claims] 1. A rolling piston (46) with a cylindrical outer peripheral surface rolls within a cylindrical cylinder dea (14) formed in the housing (12), and the working chamber (56) is connected to the suction chamber ( 84)
In a rolling piston rotary fluid machine of the type that sucks in and discharges fluid by cooperating with a vane that partitions the housing into a discharge chamber (82) and a discharge chamber (82), the housing (12) is provided with an outer surface of the cylinder bore (14). a vane chamber (54) consisting of a cylindrical bore (52) having an axis (0) and intersecting the outer peripheral surface of the rolling piston (46) in its lowest position;
't- the cylinder is formed parallel to A (14) and adjacent to A (14) over the entire length of A (14);
6) Partial cylindrical shape extending over the entire length of the vane chamber (54) over an angular range such as to maintain a sufficient sealing area between the vane chamber and the peripheral wall of the vane chamber at the lowest position, and having an outer diameter slightly smaller than the vane chamber radius. outer peripheral wall (60)
and a sealing edge (72) that slides into contact with the rolling piston over its entire length.
2) is rotatably supported by an arc-type swinging vane (58
), and the arc-type swinging vane (58) is biased to rotate in a direction in which the sealing edge (72) contacts the rolling piston (46) by a biasing means (76). A rolling piston type rotary fluid machine. 2. The inner diameter of the inner circumferential wall of the vane chamber (54) and the outer diameter of the outer circumferential wall (60) of the swing vane (58) do not substantially come into contact with the circumferential wall of the swing vane chamber; The rolling piston type rotary fluid machine according to claim 1, wherein a sealing gap of a minute distance is formed between the peripheral wall and the outer peripheral wall of the swing vane. 3. The biasing means (76) has one end attached to the housing (1).
2) and the other end is fixed to the swing vane (58), and the preload of the spring is such that the spring load is substantially zero at the lowest position of the rolling piston (46). The rolling piston type rotary fluid machine according to claim 1, wherein the rolling piston type rotary fluid machine is set to be maximum at the highest position. 4. The rolling piston type rotary fluid machine according to claim 3, wherein the spring (96) is disposed inside the swing vane (58). 5. A layer of elastic material (
50) The rolling piston type rotary fluid machine according to claim 1, characterized in that: 50) is provided. 6. Side plates (
62, 64) are provided, an arc-shaped #I (98) is provided on the outer surface of the side plate, and an arc-shaped #I (98) is provided in the groove (98) with a spring biased outward in the axial direction. The rolling piston type rotary fluid machine according to claim 1, wherein the sealing member (100) is fitted. 7. Partial cylindrical outer peripheral wall (60) of the swing vane (58)
) is provided with a partially cylindrical notch (102), into which is fitted a partially cylindrical sealing member (104) biased radially outwardly by a spring. A rolling piston type rotary fluid machine according to claim 1. 8. The rolling piston type rotary fluid machine according to claim 1, wherein the machine is a rotary compressor that discharges compressible fluid. 9. The rolling piston type rotary fluid machine according to claim 1, wherein the machine is a pump that discharges incompressible fluid.