JP4529328B2 - Compressor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a compressor.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a compressor used in, for example, a pulse tube refrigerator has a piston and a cylinder that are fitted to each other to form a compression chamber, a linear motor that drives the cylinder in the axial direction, and 2 that supports both ends of the cylinder. With two flexure bearings.
[0003]
The flexure bearing has a substantially disk shape, an outer support portion fixed to the casing of the compressor, a flexure portion formed on the radially inner side of the outer support portion and having a plurality of spiral grooves, and the flexure portion. And an inner support portion that has a through hole. The cylinder is penetrated and fixed in the through hole of the inner support portion.
[0004]
The two flexure bearings are arranged with the spiral grooves swirling in opposite directions. As a result, when the cylinder is driven and moved in the axial direction, a force in the opposite direction in the circumferential direction acts on both ends of the cylinder, and the vibration in the torsional direction of the cylinder is canceled by the force in the opposite direction in the circumferential direction. The vibration of the cylinder, and hence the vibration of the compressor is reduced.
[0005]
[Problems to be solved by the invention]
However, since the conventional compressor has the two flexure bearings arranged in opposite directions, the piston is inclined with respect to the piston axis by the force in the circumferential direction opposite from the flexure bearing. Move while. As a result, there is a problem that the cylinder comes into contact with the piston, which causes vibration of the compressor. Further, there is a problem that the cylinder and the piston are worn due to the contact between the cylinder and the piston.
[0006]
SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a compressor that can reliably prevent vibrations and has little wear on cylinders and pistons.
[0007]
[Means for Solving the Problems]
In order to achieve the above object, a compressor according to a first aspect of the present invention includes a compression element that fits together and forms a compression chamber, a linear motor that axially drives one of the compression elements, and the drive A compressor comprising two flexure bearings supporting both ends of the compression element to be
The two flexure bearings are characterized in that when the compression element moves in the axial direction, the portions supporting the compression element are arranged in the same direction so as to rotate in the same direction.
[0008]
According to the compressor of the first aspect, when the compression element is driven by the linear motor and moves in the axial direction, the two flexure bearings are arranged in the same direction. The part supporting the compression element rotates in the same direction. Thereby, one compression element supported by the two flexure bearings moves without contacting the other compression element. Therefore, the compressor does not generate vibration due to contact between the compression elements. Further, since the two compression elements do not contact each other, wear is reliably prevented.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.
[0010]
FIG. 1 is a cross-sectional view showing a compressor according to an embodiment of the present invention. The compressor includes a piston 1 and a cylinder 2 as compression elements, and the piston 1 and the cylinder 2 are fitted to each other to form a compression chamber 3. The cylinder 2 is connected to a coil portion 12 via a connecting member 11, and the coil portion 12 is inserted into a space 14 formed open to one end of a substantially cylindrical yoke 13. It is made to oppose the permanent magnet 15 arrange | positioned at the radial inside of the space 14. FIG. The coil unit 12, the yoke 13, and the permanent magnet 15 constitute a linear motor 5. The end of the piston 1 that is not fitted to the cylinder 2 is fixed to a casing (not shown). A gas passage 17 extending in the axial direction is provided at the center of the piston 1. Both ends of the cylinder 2 are connected to substantially disc-shaped flexure bearings 7, 7.
[0011]
FIG. 2A is a diagram showing the flexure bearing 7. The flexure bearing 7 includes an outer support portion 21, a flexure portion 23 including three spiral grooves 22, 22, 22 formed on the radially inner side of the outer support portion 21, and a radially inner side of the flexure portion 23. And an inner support portion 26 having a through hole 25. The cylinder 2 is penetrated and fixed in the through hole 25 of the inner support portion, and the outer support portion 21 is fixed to a casing (not shown). The flexure portion 23 sandwiched between the outer support portion 21 and the inner support portion 26 is relatively easily deformed in the direction perpendicular to the paper surface of FIG. 2A, but hardly deforms in the radial direction of the flexure bearing. Thus, the cylinder fixed by the inner support portion 26 is supported so as to be movable in the axial direction with respect to the casing fixed by the outer support portion 21.
[0012]
The two flexure bearings 7 and 7 are arranged in the same direction with the spiral grooves 22 swirling in the same direction.
[0013]
When the compressor having the above configuration is operated, an alternating current is applied to the coil portion 12 located in the magnetic circuit formed by the yoke 13 and the permanent magnet 15 via a wiring (not shown). As a result, axially alternating thrust is generated in the coil portion 12, and the cylinder 2 connected to the coil portion 12 via the connecting member 11 advances and retreats in the axial direction. As a result, the volume of the compression chamber 3 formed between the cylinder 2 and the piston 1 decreases and increases, and a pressure fluctuation is generated in the gas in the compression chamber 3. The pressure fluctuation of the gas is sent through a gas passage 17 of the piston toward a regenerator (not shown), a pulse tube, and a buffer tank connected in series to the compressor, and the pressure fluctuation of the gas is sent by the buffer tank. Are converted, and cold heat is generated at the low temperature end of the pulse tube.
[0014]
When the cylinder 2 moves in the axial direction, the inner support portion 26 of the flexure bearing fixed to the cylinder 2 also moves in the axial direction, and the flexure portion 23 connected to the inner support portion 26 is deformed. . When the flexure portion 23 is deformed, the inner support portion 26 rotates counterclockwise in the direction in which the spiral groove 22 of the flexure portion 23 faces radially outward from the center, that is, in FIG. Since the two flexure bearings 7 and 7 for fixing both ends of the cylinder 2 are arranged in the same direction of the spiral groove 22, when the cylinder 2 moves in the axial direction, the two flexure bearings 7 and 7 7 inner support portions 26 rotate in the same direction. Therefore, the cylinder 2 rotates with its axis substantially coincided with the piston 1. As a result, the cylinder 2 and the piston 1 do not come into contact with the shaft as in the conventional case, so that vibration and wear due to the contact between the cylinder and the piston can be reliably prevented. Thereby, the vibration of the compressor can be effectively prevented, and the durability of the compressor can be effectively improved.
[0015]
FIG.2 (b) is a figure which shows the flexure bearing of other embodiment. Since this embodiment is the same as the embodiment of FIG. 1 except for the flexure bearing, FIG. 1 is used instead. The flexure bearing 31 includes a substantially annular outer support portion 32, three plate springs 34, 34, 34 having one end fixed to the inner surface of the outer support portion 32, and other plate springs 34, 34, 34. It consists of a substantially triangular inner support portion 35 with fixed ends. The plate springs 34, 34, 34 face the tangential direction of the outer support portion 32. The plate springs 34, 34, 34 are formed of laminated steel plates in which a plurality of steel plates are laminated in the axial direction of the flexure bearing. The other ends of the plate springs 34, 34, 34 are fixed to flanges 35a, 35a, 35a formed so as to protrude clockwise from the apex of the inner support portion 35 in FIG. . The inner support portion 35 has a through hole 36 in the center, and the cylinder 2 is fitted and fixed to the through hole 36. The inner support portions 35 of the flexure bearing are fixed to both ends of the cylinder 2, and the cylinder 2 is supported by the two flexure bearings 31 and 31. The two flexure bearings 31, 31 are arranged in the same direction so that the protruding directions of the flange portions 35a, 35a, 35a from the apex of the inner support portion are the same.
[0016]
When the compressor including the flexure bearing 31 is driven, the cylinder 2 advances and retracts in the axial direction, and the inner support portion 35 fixed to the cylinder 2 advances and retracts in the axial direction. At this time, the three leaf springs 34, 34, 34 are deformed, and the inner support portion 35 to which the other ends of the three leaf springs 34, 34, 34 are fixed is shown in FIG. The bearing 31 rotates clockwise. Since the two flexure bearings 31, 31 are arranged in the same protruding direction of the flanges 35a, 35a, 35a from the apex of the inner support portion, both ends of the cylinder 2 rotate in the same direction. . As a result, the cylinder 2 rotates with the piston 1 and the shaft substantially aligned with each other, so that the cylinder 2 and the piston 1 do not come into contact with each other because the shaft is twisted as in the prior art. As a result, vibration and wear due to contact between the cylinder and the piston can be surely prevented, noise of the compressor can be effectively prevented, and the durability of the compressor can be effectively improved.
[0017]
In the above embodiment, the flexure bearings 7 and 31 are the flexure bearing 7 having the spiral grooves 22, 22, 22 and the flexure bearing 31 having the leaf springs 34, 34, 34, but the cylinder moves. Then, any flexure bearing may be used as long as the flexure bearing is formed so that the connecting portion with the cylinder rotates.
[0018]
In the said embodiment, although the flexure bearings 7 and 31 supported the cylinder 2, you may support a piston. In this case, when the piston is moved by the linear motor, contact between the piston and the cylinder is effectively prevented.
[0019]
Although the said compressor was used for the pulse tube refrigerator, you may use it for other refrigerators, such as a Stirling refrigerator, for example.
[0020]
【The invention's effect】
As is clear from the above, according to the compressor of the first aspect of the present invention, a compression element that fits together and forms a compression chamber, a linear motor that drives one of the compression elements in the axial direction, In the compressor comprising two flexure bearings that support both ends of the driven compression element, the two flexure bearings have portions that support the compression element when the compression element moves in the axial direction. Since they are arranged in the same direction so as to rotate in the same direction, one of the compression elements supported by the two flexure bearings rotates with the other compression element approximately aligned with its axis, The compressor vibration due to the contact of the compression element can be effectively prevented, and further, the wear of the compression element can be effectively prevented.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a compressor according to an embodiment of the present invention.
2A is a plan view showing a flexure bearing provided in the compressor of FIG. 1, and FIG. 2B is a plan view showing a flexure bearing provided in a compressor according to another embodiment. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Piston 2 Cylinder 3 Compression chamber 5 Linear motor 7 Flexure bearing 11 Connection member 12 Coil 13 Yoke 14 Space 15 Permanent magnet 17 Gas passage

Claims (1)

A compression element (1, 2) that fits together and forms a compression chamber (3), a linear motor (5) that drives one of the compression elements (1, 2) in the axial direction, and the driven In the compressor comprising two flexure bearings (7, 7) supporting both ends of the compression element (2)
The two flexure bearings (7, 7) are arranged in the same direction so that when the compression element (2) moves in the axial direction, the portion supporting the compression element (2) rotates in the same direction. The compressor characterized by having.

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