JPH0652077B2 - Rolling piston type rotary fluid machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a rotary fluid machine that can be used as a vacuum pump or a compressor, and more particularly to a rolling piston type rotary fluid machine. The present invention particularly relates to a rolling piston type rotary fluid machine which does not require lubrication of moving parts.

[Prior art]

A rolling piston with a cylindrical outer peripheral surface rolls in a cylindrical cylinder bore formed in the housing, and a vane that partitions the working chamber into a suction chamber and a discharge chamber cooperates with this rolling piston to suck and discharge the fluid. Rolling piston rotary fluid machines of the type known are known. In this conventional rolling piston type rotary fluid machine, a vane that partitions the working chamber into a discharge chamber and a suction chamber is a flat plate, and the vane is stored in a guide slot formed in the housing of the fluid machine. It is brought into sliding contact with the piston so that it follows the rolling piston by the force of the spring. During the operation of this fluid machine, the load due to the pressure difference between the suction pressure and the discharge pressure acts on the vane, so that the frictional force applied to the sliding portion between the guide slot and the vane becomes large, so that the friction loss of the fluid machine is lost. Grows larger.

This problem is solved by the rolling piston type rotary fluid machine disclosed in JP-A-60-175791. In this fluid machine, a cylindrical vane chamber is formed in the housing, and an arc type swinging vane is arranged in the vane chamber. This swinging vane has a partially cylindrical outer peripheral wall, and can swing about its rotation axis. The swinging vane is biased toward the rolling piston by a spring, and a sealing edge provided at the tip of the vane is pressed against the outer peripheral surface of the piston to seal between the vane and the piston. In this fluid machine, the load due to the pressure difference between the suction chamber and the pressure chamber acts in the normal direction to the outer peripheral wall of the arc type swinging vane and in the radial direction to the rotating axis of the swinging vane. There is an advantage that the friction loss of the swinging vane due to the pressure difference can be minimized.

[Problems of conventional technology]

However, in the fluid machine of JP-A-60-175791, since the sealing edge at the tip of the swinging vane and the outer peripheral surface of the rolling piston are in sliding contact with each other, wear of both is prevented and heat generation of the sliding portion is suppressed, In addition, lubrication of sliding parts is indispensable to further reduce sliding friction. Such lubrication is not preferable when the fluid machine is used as a vacuum pump. This is because the oil mist generated in the working chamber of the fluid machine due to lubrication flows back to the space to be evacuated and contaminates the space when the operation of the machine is stopped. Also, when used as a gas compressor,
Oil mist mixes in the compressed gas and contaminates it.
When used as a refrigerant compressor of a refrigeration system, it is necessary to add lubricating oil to the refrigerant.

[Object of the Invention]

It is an object of the present invention to improve the rolling piston type rotary fluid machine with arc type swinging vanes so that no lubrication of moving parts is required.

Another object of the present invention is to further reduce the sliding friction loss of the moving part.

[Means and Actions for Solving Problems]

In order to solve the problems of the prior art, the present invention provides an arc-type swinging vane that accommodates a rolling piston in a working chamber formed in a housing and divides the working chamber into a suction chamber and a discharge chamber in a sealing relationship. It is swingably supported by the housing, and the piston rolls along the inner wall of the working chamber while the sealing edge of the arc-shaped profile of the swing vane follows the outer peripheral surface of the piston in a sealing relationship, so that suction and discharge of fluid can be performed. In the rolling piston type rotary fluid machine of the type to be performed, it is composed of a member driven in synchronization with the arc type oscillating vane and the rolling piston, and a predetermined distance is provided between the sealing edge of the arc type oscillating vane and the outer peripheral surface of the piston. The swinging vane is swung so that the sealing edge follows the outer peripheral surface of the piston while maintaining a small clearance. Characterized in that a order of positive swing control mechanism outside the working chamber.

According to the present invention, the positive swing control mechanism including the members driven in synchronization with the arc type swing vane and the rolling piston is provided outside the working chamber. The action of maintaining a predetermined minute clearance between the sealing edge of the arc type swinging vane and the outer peripheral surface of the piston is performed without being affected by the pressure of the fluid of FIG. Therefore, even if the sealing edge is not in contact with the outer peripheral surface of the piston, it is possible to reliably follow it and maintain a minute clearance at all rotation angles, while maintaining a sufficient sealing effect. Also, it is possible to solve the problems of power loss due to sliding friction between the arc type swinging vane and the outer peripheral surface of the piston, and their wear.

〔Example〕

Embodiments of the present invention will be described below with reference to the accompanying drawings.
Referring to FIGS. 1-3, fluid machine 10 has a housing 12 made of a light alloy such as an aluminum alloy. The housing 12 is composed of a cylinder 14, a front side plate 16, and a rear side plate 18. Cylinder 1 in the illustrated embodiment
4 and the front side plate 16 are integrally formed, and the cylinder 14
The rear plate 18 and the rear plate 18 are airtightly fastened, for example, by four bolts 20. An extension portion 22 extends forward from the front side plate 16, and a cover 24 is attached to the extension portion 22 by a bolt 2
It is concluded by 6.

A cylindrical cylinder bore 28 is formed in the cylinder 14, and a rolling piston 30 having a cylindrical outer peripheral surface is mounted therein. The piston 30 can be made of light alloy. In order to allow the piston 30 to roll without sliding contact between the side surface of the piston 30 and the side plates 16 and 18, and to perform a seal between the two so that fluid leakage can be sufficiently prevented, the piston 30 The axial length of is preferably set so that a minute clearance of about 10 μm is secured on both sides of the piston 30 at the steady motion temperature of the engine.

The piston 30 is driven by an eccentric shaft 32. The eccentric shaft 32 is coaxially arranged with respect to the cylinder bore 28, and both ends thereof are bearing assemblies 34, 36.
It is pivotally supported by the cover 24 and the rear side plate 18 via. A drive pulley (not shown) can be mounted on the free end of the shaft 32 in a known manner to rotate the shaft. The shaft 32 has an eccentric portion 38, and the rolling piston 30 is coaxially mounted around the eccentric portion 38 via a bearing assembly 40. As shown in FIG. 1, the axis of the eccentric portion 38 is eccentric to the axis of the shaft 32 by a distance ρ. Therefore, when the shaft 32 is rotated, the axis of the piston 30 moves along a locus of a circle having a radius ρ centered on the axis of the shaft 32. In order to prevent fluid leakage while preventing the inner wall surface of the cylinder bore 28 from slidingly contacting the outer peripheral surface of the piston 30, the piston 3
The outer diameter of 0 is set so that a radial clearance of about 10 μm is formed between the outer peripheral surface of the piston and the inner wall surface of the cylinder bore. If such a radial clearance is provided, theoretically the outer peripheral surface of the piston 30 does not contact the inner wall surface of the cylinder bore 28, so that the piston 30 does not roll on the inner wall surface of the cylinder bore, and the piston 30 does not rotate on the shaft eccentric portion 38. The rotation motion centering around the shaft 32 will be performed almost exclusively, and the revolution motion centering around the shaft 32 axis will be performed. However, such movement of the piston 30 is also referred to as "rolling" in this specification. Eccentric shaft 32 and cover 2
4, the front side plate 16 and the rear side plate 18 are sealed by the seal members 42, 44 and 46.

As best seen in FIG. 3, the cylinder 14 is formed with a cylindrical bore 48 parallel to and adjacent to the cylinder bore 28, which defines a vane chamber 50. Since the bore 48 intersects the cylinder bore 28,
The vane chamber 50 merges with a working chamber 52 defined by the cylinder bore 28.

An arc type swinging vane 54 made of an aluminum alloy or the like is coaxially housed in the vane chamber 50. This swing vane 54 includes a partially cylindrical arc portion 56, fan-shaped side plates 58 and 60 for supporting the arc portion 56, a sealing edge 62 having an arc-shaped profile, and an arc portion 56.
And a vane shaft 6 coaxial therewith. The vane shaft 64 is integrally rotatably fixed to the side plates 58 and 60,
It is pivotally supported by front and rear side plates 16, 18 of the housing via bearing assemblies 66, 68. Sealing members 70 and 72 seal between the side plates 16 and 18 and the vane shaft 64. A radial clearance of about 10 μm is provided between the outer peripheral surface of the arc portion 56 of the swinging vane 54 and the bore 48, and the outer peripheral surface of the arc portion 56 does not slide on the inner wall surface of the vane chamber 50, but is sufficient between both. A fluid seal is ensured. Similarly, a minute axial clearance is also provided between the outer peripheral surfaces of the side plates 58 and 60 of the swing vane and the end surface of the vane chamber 50. The circumferential extent of the arc portion 56 is such that at any swing position of the swing vane 54, a sufficient angular range of sealing area is provided between the interior wall of the vane and the arc portion.

As shown in FIG. 3, the housing 12 has a suction port 74.
And a discharge port 76 are provided, which are the working chamber 5
It is open to 2. A discharge valve 82 including a reed valve 78 and a stopper 80 is provided in the discharge port 76, and is fixed to the housing 12 by a bolt 84.

A positive swing control mechanism 88 is provided in a chamber 86 defined between the cover 24 and the front plate 16. When the rolling piston 30 rolls, the swing control mechanism 88 keeps a small clearance between the arcuate surface of the sealing edge 62 of the swing vane 54 and the outer peripheral surface of the rolling piston 30 while keeping the sealing edge 62 stable. The swinging motion of the swinging vane 54 is controlled so as to follow the outer peripheral surface of the piston. The swing control mechanism 88 includes a cam plate 90 fixed to the eccentric shaft 32 in the chamber 86.
And a cam follower 92 that engages with this cam plate,
It has a rocking lever 94 that connects the cam follower and the vane shaft 64. The cam plate 90 has a circular profile with the same radius as the radius of the piston 30, and its axis is eccentric in the same direction as the axis of the eccentric portion of the eccentric shaft 32 by the same distance. Therefore, no matter which angular position the piston 30 rolls as the eccentric shaft 32 rotates, the cam plate 90 rotates so that its profile always matches the profile of the piston 30. The cam plate 90 is preferably formed of a material having the same coefficient of thermal expansion as the piston 30, but on the other hand, in order to prevent friction due to engagement with the cam follower 92, it is formed of a wear resistant metal such as a steel alloy. Preferably. When the piston 30 is made of a light alloy and the cam plate 90 is made of a steel alloy, it is preferable that the radiuses of the two be equal at the steady operating temperature of the fluid machine 10.

In the illustrated embodiment, the cam follower 92 comprises a commercially available rolling bearing assembly. The bearing assembly 92 includes an outer race 96 and an inner race 98.
The inner race 98 is fitted to a pin 102 projecting from the outer end of the swing lever 94 in parallel with the vane shaft 64. The inner end of the lever 94 is integrally connected to the vane shaft 64. Therefore,
When the swinging vane 54 swings around the vane shaft 64, the cam follower (that is, the bearing assembly) 92.
It will be understood that also swings around the vane shaft 64. The length and angular position of the swing lever 94 are determined so that the axis of the cam follower 92 coincides with the axis of the arcuate profile of the sealing edge 62 of the swing vane 54. In the illustrated embodiment, the outer diameter of the outer race 96 of the cam follower 92 is larger than the radius of the arcuate profile of the sealing edge 62 by, for example, about 10 μm. Thus, the profile of the outer race 96 is coaxial but slightly radially outward of the profile of the sealing edge 62. With this configuration, when the cam follower 92 is in contact with the cam plate 90,
A clearance of about 10 μm is secured between the outer peripheral surface of the piston 30 and the arcuate surface of the vane edge 62 of the swinging vane 54. Instead of the above-mentioned configuration, the radius of the cam plate 90 may be set to be slightly larger than the radius of the piston 30, and the radius of the cam follower 92 may be the same as the radius of the sealing edge 62. Can be secured.

The cam follower 92 of the swing lever 94 is the cam plate 90.
Is urged by the spring 104 in the direction of abutting against the. A lower end of the spring 104 is supported by a lower spring bearing 106 fixed to the lever 94, and an upper end thereof is supported by an upper spring bearing 108. The upper spring support 108 is supported by the front side plate 16 via a pin 110.

Next, to explain the operation of this fluid machine, the suction port 74 is connected to the space to be evacuated through an appropriate conduit when used as a vacuum pump, and the discharge port when used as a compressor. 76 is properly connected to the pressure feeding line.

When the eccentric shaft 32 rotates by receiving an external driving force, the rolling piston 30 rolls as described above, and
The cam plate 90 rotates integrally with the shaft 32.
The cam follower 92 is pressed against the cam plate 90 by the action of the spring 104, and the cam follower 92 follows the profile of the cam plate 90. Therefore, as the cam plate 90 rotates, the swing lever 94 causes the vane shaft 6 to move.
Reciprocating rocking motion is performed around 4 and the vane shaft 6
The rocking vane 54 integrated with 4 is forcibly rocked. Second
The figure shows the angular position of the cam plate 90 when the swing lever 94 swings to the top dead center position, and each of FIGS. 4, 5 and 6 shows the angular position when the phase advances by 90 °. . Also,
FIGS. 3, 7, 8, and 9 show the positions of the rolling piston 30 and the swinging vane 54, and are shown in FIGS.
It corresponds to the phase of FIG. As described above, since the outer diameter of the cam follower 92 is slightly larger than the radius of the arcuate profile of the sealing edge 62, the piston 30
The swinging vanes 54 are forcibly swung while maintaining a slight clearance between the outer peripheral surface of the and the sealing edge 62. This small clearance forms a sealing gap between the piston 30 and the swinging vane 54, which allows the piston 30 to rotate without sliding contact with the sealing edge 62 of the swinging vane 54, and through this gap. As a result, it is possible to effectively prevent the fluid from blowing through from the high pressure side region to the low pressure side region in the working chamber 52.

Sealing between the inner wall surface of the cylinder bore 28 forming the working chamber 52 and the outer peripheral surface of the piston 30 is performed by a minute clearance therebetween. Since this minute clearance is provided, the piston 30 can roll without slidingly contacting the inner wall surface of the cylinder bore and substantially preventing blow-through of fluid. Further, the seal between the inner wall surface of the bore 48 forming the vane chamber 50 and the outer peripheral surface of the arc portion 56 of the swing vane 54 is performed by a slight clearance therebetween. Further, minute clearances are provided at both axial ends of the piston 30 and the swing vane 54, respectively.
They move without sliding contact with the housing 12, and substantially prevent blow-through of fluid. Thus, the stationary housing 12 of this fluid machine 10
Since there is no sliding part between the movable part 30 and 54 and the sliding part, and in particular, there is no sliding part between the swinging vane 54 and the piston 30, it is necessary to lubricate the working chamber 52 with lubricating oil or the like. It is possible to operate the machine without it.

The rolling piston 30 rolls, and the swinging vane 5
As the No. 4 follows, two variable capacity spaces are formed in the working chamber 52. In the phase of Figs.
Is in the suction stroke, and this space 110 acts as a suction chamber. In the phases of FIGS. 7, 8 and 9, the space 112 is in the compression and discharge stroke and acts as a discharge chamber.

When the piston 30 rolls from the phase shown in FIG. 7 to the phases shown in FIGS. 8, 9, and 3, the volume of the variable volume space 110 increases,
The fluid is sucked from the suction port 74. When the piston further rolls, the space 112 is cut off from the suction port (7th space).
(FIG. 8), the volume gradually decreases and the fluid is discharged from the discharge port 76 (FIGS. 8 and 9). The pump action is performed by repeating the above cycle.

〔The invention's effect〕

As described above, the present invention, in a rolling piston type rotary fluid machine provided with an arc type swinging vane, in order to control the swinging motion of the swinging vane, is synchronized with the arc type swinging vane and the rolling piston, respectively. A positive swing control mechanism composed of driven members is provided outside the working chamber,
Since a predetermined small clearance is always secured between the sealing edge of the swinging vane and the outer peripheral surface of the piston, there is no sliding portion in the working space. Therefore, it is not necessary to lubricate the movable parts, and the working fluid can be maintained in a clean state, which is an excellent technical effect. Further, sliding friction loss is reduced, so that power consumption is reduced. Also, wear on the moving parts is reduced, which significantly improves the durability and reliability of the machine.

Also, when the positive swing control mechanism is composed of a cam plate and a cam follower, the clearance between the sealing edge and the piston can be accurately controlled, so that the blow-through of fluid from the high pressure side to the low pressure side is minimized. Therefore, it is possible to provide a fluid machine having excellent performance.

[Brief description of drawings]

1 is a sectional view of the fluid machine of the present invention, and FIG. 2 is a sectional view of FIG.
The sectional view taken along the line II-II shows the cam plate rotated to the top dead center position. FIG. 3 shows the sectional view taken along the line III-III in FIG. 1 where the piston is in phase with FIG. FIGS. 4, 5 and 6 are sectional views similar to FIG. 2 showing that the cam plates are in a phase further advanced by 90 °, and FIGS.
FIG. 9 is a sectional view similar to FIG. 3 and shows the pistons in phases corresponding to FIGS. 4, 5 and 6, respectively. 10 ... Fluid machine, 12 ... Housing, 24 ... Cover, 28 ... Cylinder bore forming working chamber 52, 30 ... Rolling piston, 32 ... Eccentric shaft, 38 ... Eccentric part of shaft 32, 48 ... ... Bore forming the vane chamber 50, 50 ... Vane chamber, 52 ... Working chamber, 54 ... Arc type swinging vane, 56 ... Arc portion of swinging vane, 58, 60 ... Swing vane side plate, 62 ... … Sealing edge of swing vane, 64 …… vane shaft, 88 …… active swing control mechanism, 90 …… cam plate, 92 …… cam follower, 94 …… swing lever, 104 …… spring.

Claims (3)

[Claims] 1. A rolling piston is housed in a working chamber formed in a housing, and an arc type swinging vane that divides the working chamber into a suction chamber and a discharge chamber in a sealing relationship is swingably supported by the housing. A rolling piston type rotary fluid of the type in which the piston rolls along the wall surface of the working chamber while the sealing edge of the arc-shaped profile of the oscillating vane follows the outer peripheral surface of the piston in a sealing relationship. In a machine, the arc type swing vane and a member that are driven in synchronism with the rolling piston are respectively provided, and the sealing edge is maintained while maintaining a predetermined minute clearance between the sealing edge of the arc type swing vane and the outer peripheral surface of the piston. Activates the positive swing control mechanism to swing the swing vane to follow the outer peripheral surface of the piston. A rolling piston type rotary fluid machine characterized by being provided outside the chamber. 2. The positive swing control mechanism has (a) a profile equal to or slightly larger than the profile of the rolling piston, the axis of which moves in the same phase along the locus of the piston axis. Therefore, it has a cam plate that rotates in synchronization with the piston, and (b) a circular profile having a radius slightly larger than or equal to the radius of the arc-shaped profile of the sealing edge of the swinging vane, and on the outer circumference of the cam plate. (C) The cam follower and the (c) swingable vane swing around the swing axis of the swing vane in synchronism with the swing vane, and the axis of the cam follower has the same phase along the trajectory of the axis of the sealing edge of the swing vane. A rocking lever that pivotally supports the cam follower so that the cam follower can be rocked, and (d) a biasing means that biases the cam follower to contact the cam plate. Become Te claims as set forth in claim 1, wherein the rolling piston type rotary fluid machine. 3. A rolling piston type rotary fluid machine according to claim 2, wherein said cam follower comprises a rolling bearing assembly carried by a swing lever.