JPH1018985A - Fluid compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid compressor capable of dynamically balancing its crankshaft having a crank part for rotating a roller. SOLUTION: A fluid compressor has a compression mechanism part 3 which rotates a roller 11 eccentrically arranged in a cylinder 5 to compress refrigerant gas inducted between the cylinder 5 and the roller 11. The compression mechanism part 3 has a crankshaft 9 which is arranged inside the roller 11 and is provided with a crank part 9a for rotating the roller 11 in the cylinder 5. The crankshaft 9 is provided with two counterweights 9b and 10 sandwiching the crank part 9a in the axial direction thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a compression mechanism for compressing a fluid to be compressed such as a refrigerant gas, which is used in, for example, a refrigeration cycle apparatus.

[0002]

2. Description of the Related Art Conventionally, a fluid compressor has been used which is used in a refrigeration cycle apparatus or the like and compresses and discharges a refrigerant gas introduced therein. As one of such fluid compressors, there is a helical blade type fluid compressor represented by Japanese Patent Publication No. 7-107391. Since this fluid compressor has a structure in which a cylinder and a roller rotate, the peripheral speed becomes large, and it is necessary to consider sliding loss in a bearing. Therefore, a fluid compressor shown in FIG. 3 has been considered as a configuration for reducing the sliding speed by reducing the peripheral speed.

[0003] In Fig. 3, reference numeral 1 denotes a sealed case whose axial direction is directed horizontally. The compression mechanism 3 and the electric motor 4 are accommodated in the closed case 1. In other words, the right part in FIG.

[0004] The compression mechanism 3 has a cylinder 5 which is a hollow cylindrical body whose both ends are open. The above cylinder 5
The main bearing 6 is mounted and fixed on one side (the left side in the figure) of the cylinder via a fixture 7, and the opening of the cylinder 5 is closed. On the other side (the right side in the drawing), a sub-bearing 8 is mounted and fixed via a fixture 7, and the opening of the cylinder is closed.

[0005] A crankshaft 9 is inserted along the axis of the main bearing 6 and the sub-bearing 8 and is rotatably supported. The crankshaft 9 not only penetrates into the cylinder 5 between the main bearing 6 and the sub-bearing 8 but also protrudes from the main bearing 6 to the left in the drawing, and a rotating shaft of the electric motor unit 4 described later. Construct 9Z. Further, on the peripheral surface of the crankshaft 9 between the main bearing 6 and the sub-bearing 8, there is integrally provided a crank portion 9a having an axis b that is eccentric by a predetermined dimension e from the crankshaft axis a.

A roller 11 is interposed between the crankshaft 9 and the cylinder 5 described above. The roller 11 is a cylindrical body whose both ends are open, and its axial length matches the axial length of the cylinder 5.

A stepped bore 12 is provided on the inner periphery of the roller 11.
In particular, a portion of the crankshaft 9 opposed to the crank portion 9a has the same width as these crank portions and is rotatably slidably in contact with the outer peripheral surface of the bore shaft support portion 1.
2a.

A spiral groove 14 is provided on the outer peripheral surface of the roller 11 to gradually decrease the pitch from the end on the side where the sub-bearing 8 is attached to the end on the side where the main bearing 6 is attached. The blade 15 is wound so as to be able to enter and exit freely.

On the other hand, the electric motor unit 4 includes a rotor 45 fitted to a rotating shaft 9Z of the crankshaft 9 protruding from the main bearing 6, and the case body with a predetermined gap from the outer peripheral surface of the rotor. 1a Stator 4 fitted on inner peripheral surface
And 6.

In the fluid compressor configured as described above, the refrigerant gas as the fluid to be compressed is compressed as follows. That is, the motor unit 4 is energized to rotate the crankshaft 9 integrally with the rotor 45. The rotational force of the crankshaft 9 is transmitted to the roller 1 via the crank 9a.
1 is transmitted.

The crank 9a is eccentrically provided, and the inner pivot 12a of the roller 11 is rotatably engaged therewith, so that the roller 11 is pressed by the crank 9a. In addition, since the Oldham mechanism 13 interposed between the main bearing 6 and the roller 11 regulates the rotation of the roller, the roller 11 makes a revolving motion without rotating.

On the other hand, low-pressure refrigerant gas is sucked from the suction pipe 17 and guided to the compression chamber 16. With the turning movement of the roller 11, the rolling contact position of the roller with respect to the inner peripheral surface of the cylinder 5 gradually moves in the circumferential direction, and the blade 15 moves in and out of the spiral groove 14. That is, blade 1
5 moves in the radial direction of the roller 11.

[0013] The refrigerant gas guided to the compression chamber 16 is sequentially transferred to the compression chamber 16 with the swirling motion of the roller 11 from where the blade 15 is formed in a spiral shape. The pitch of the blades 15 is set so as to gradually decrease from the suction portion A to the discharge portion B. Since the volume of the compression chamber 16 partitioned by the blades is gradually reduced, the refrigerant gas is sequentially transferred through the compression chamber. Compressed during
In the compression chamber closest to the discharge section B, the pressure rises to a predetermined pressure and is increased.

The high-pressure gas is discharged from the compression chamber 16 of the discharge section B, and is guided to the space on the motor section 4 side. Then, the air is guided to the space on the side of the compression mechanism 3 and is filled. The high-pressure gas is guided to the discharge pipe from where the open end of the discharge pipe 18 is opposed to this space, and is led to the condenser therefrom.

As described above, in the fluid compressor of the present invention, the roller 11 is swirled with respect to the fixed cylinder 5 in the compression mechanism section 3. The peripheral speed decreases.
Therefore, the sliding loss on the thrust surface of the roller 11 can be reduced, and the compression efficiency can be improved instead.

[0016]

The above-mentioned conventional fluid compression mechanism in which the roller 11 makes a revolving motion has the following problems. That is, since the crankshaft 9 is formed with the crank portion 9a, it is necessary to cancel the imbalance due to the turning motion of the rollers 11 and reduce the vibration. Therefore, a balance weight 9b is provided on the peripheral surface between the main bearing 6 pivot portion and the auxiliary bearing 8 pivot portion.

However, if there is only one balance weight, dynamic balance cannot be attained. Therefore, it is necessary to attach at least one to each of the main bearing side and the sub-bearing side of the crank portion 9a. However, when the crankshaft 9 in which two balance weights are integrally provided is used, there is a problem that the balance weight cannot pass through the lumen pivot 12a and cannot be assembled. Although it is conceivable to use a balance weight thinner than the lumen pivot 12a, there is a possibility that sufficient dynamic balance cannot be obtained.

On the other hand, a second balance weight can be provided on the motor section 4 side, but there is a possibility that the crankshaft 9 may be bent in a high rotation range. Accordingly, the present invention provides a fluid compressor for compressing a fluid to be compressed introduced between a cylinder and a roller by rotating the roller eccentrically arranged in the cylinder, thereby forming a crank for rotating the roller. It is an object of the present invention to provide a fluid compressor that can balance the dynamics of a crankshaft and facilitate assembly.

[0019]

In order to solve the above-mentioned problems and to achieve the object, the invention according to the first aspect of the present invention is directed to the invention in which the above-mentioned cylinder and the above-mentioned roller are rotated by eccentrically moving a roller eccentrically arranged in the cylinder. And a compression mechanism for compressing the fluid to be compressed introduced between the cylinder and the compression mechanism, the compression mechanism being provided in the roller, and having a crank portion for rotating the roller in the cylinder. A crankshaft, and the crankshaft is provided with two balance weights provided so as to sandwich the crank portion in the axial direction.

According to a second aspect of the present invention, in the first aspect, the crankshaft is supported by a main bearing and a sub-bearing, and the balance weight is provided by the main bearing and the sub-bearing. And is located between.

According to a third aspect of the present invention, in the first aspect, one of the balance weights is formed integrally with the crankshaft, and the other balance weight is formed of the crankshaft. The shaft is detachably formed.

According to a fourth aspect of the present invention, in the third aspect, relative movement of the other balance weight in the circumferential direction and the axial direction with respect to the crankshaft is restricted. .

The invention described in claim 5 is the first invention.
In the invention described in 2 or 3, the compression mechanism is:
Spiral grooves formed along the peripheral surface of the roller and formed at a pitch that gradually decreases, and a plurality of compressions which are fitted into the spiral grooves so as to be able to move in and out to gradually reduce the volume of the space with the cylinder. A spiral blade that forms a partition in the chamber, and gradually compresses the compressed fluid sucked into the compression chamber on the side where the pitch of the spiral groove is large, on the side where the pitch of the spiral groove is small. It is compressed while being transferred to the chamber.

As a result of taking the above measures, the following operation occurs. In the invention described in claim 1, the crankshaft having the crank portion for rotating the roller in the cylinder is provided with two balance weights provided with the crank portion interposed therebetween in the axial direction.
A dynamic balance can be obtained, and a balance between weight balance and moment can be ensured.

According to the second aspect of the present invention, since the balance weight is disposed between the main bearing and the sub-bearing supporting the crankshaft, for example, a crank generated when the balance weight is attached to the motor side. The flexure of the shaft can be prevented.

According to the third aspect of the present invention, one of the balance weights is formed integrally with the crankshaft, and the other balance weight is formed by fitting to the crankshaft. The other balance weight can be attached after the shaft has been incorporated into the roller. For this reason, when the crankshaft is incorporated into the roller, the crankshaft can be easily inserted even if the roller has a portion having a small inner diameter such as a portion in contact with the crank portion.

In the invention described in claim 4, the relative movement of the other balance weight with respect to the crankshaft in the circumferential direction and the axial direction is restricted.
Dynamic balance can be maintained.

According to the fifth aspect of the present invention, the compression mechanism is provided along the peripheral surface of the roller with a spiral groove formed at a gradually decreasing pitch, and is fitted in the spiral groove so as to be able to freely enter and exit. A helical blade that forms a space with the cylinder into a plurality of compression chambers that gradually reduces the volume, and gradually compresses the fluid to be compressed sucked into the compression chamber on the side where the pitch of the helical groove is large. The helical groove is compressed while being transferred to the compression chamber on the side where the pitch is smaller. For this reason, a helical blade type fluid compressor with good assemblability can be provided.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A helical blade type fluid compressor disclosed herein is used for, for example, a refrigeration cycle of an air conditioner. And Note that, in this figure, the same reference numerals are given to the same functional portions as those in FIG.

As shown in FIG. 1, the closed case 1 has a case body 1a whose both ends are open with its axial direction being horizontal.
Upper lid 1b for closing one end opening of this case body 1a
And a lid plate 1c for closing the opening at the other end.

In the closed case 1, a compression mechanism 3 and a motor 4 are housed. That is, the closed case 1
In FIG. 1, the compression mechanism 3 is located on the right side and the motor section 4 is located on the left side with respect to the substantially central portion in the axial direction of FIG.

The compression mechanism 3 is a hollow cylindrical body having both ends opened, and a pair of flanges 5 are formed on the outer peripheral surfaces of both ends.
a and 5b have the cylinder 5 projected. At least one flange 5a of the cylinder 5 is press-fitted to a case main body 1a constituting the closed case 1 to fix and position the cylinder 5.

A main bearing 6 is mounted and fixed on one side (the left side in the figure) of the cylinder 5 via a fixture 7, and an opening of the cylinder is closed. On the other side (the right side in the drawing), a sub-bearing 8 is mounted and fixed via a fixture 7, and the opening of the cylinder is closed.

A crankshaft 9 is inserted along the axis of the main bearing 6 and the sub-bearing 8 and is rotatably supported. The crankshaft 9 not only penetrates into the cylinder 5 between the main bearing 6 and the sub-bearing 8 but also protrudes from the main bearing 6 to the left in the drawing, and a rotating shaft of the electric motor unit 4 described later. Construct 9Z.

The crankshaft 9 will be further described. The circumferential surface between the main bearing 6 and the sub-bearing 8 is provided at a position apart from each other and eccentric with the crankshaft axis a by a predetermined dimension e. Crank part 9a of lead b
Are provided integrally.

A balance weight 9b is provided integrally with the crankshaft adjacent to a further left portion of the crank portion 9a. The balance weight 9b is connected to the first
The eccentric projection of the crank portion 9a is eccentric to the peripheral surface portion on the opposite side via the axis.

A balance weight 10 separate from the crankshaft 9 is fitted adjacent to the right side of the crank 9a. The balance weight 10 is eccentric to a peripheral surface portion of the crank portion 9a opposite to the eccentric protruding direction. As shown in FIGS. 2A and 2B,
The movement of the balance weight 10 in the circumferential direction with respect to the crankshaft 9 is restricted by a key 50 fitted in a key groove 9c provided in the crankshaft 9. Also,
The movement of the crankshaft 9 in the axial direction is restricted by the retaining ring 51. In addition, balance weight 10
Will be described later.

Between the crankshaft 9 and the cylinder 5, there is provided a roller 11 whose material is selected from, for example, an aluminum alloy material having a lower specific gravity than iron. The roller 11 is a cylindrical body whose both ends are open, and its axial length matches the axial length of the cylinder.

The inner peripheral portion of the roller 11 has a stepped bore 12
In particular, a portion of the crankshaft 9 opposed to the crank portion 9a is
And has a width that is the same as that of the inner peripheral pivotal support portion 12a that is rotatably slidably in contact with the outer peripheral surface.

As a result, the axis b of the roller 11 coincides with the axis b of the crank 9a, and is eccentric to the axis a of the cylinder 5 or the like by the dimension e. The dimension of the outer peripheral wall of the roller 11 is set so as to be in contact with the inner peripheral wall of the cylinder 5 along the axial direction.

The sliding contact portion between the crank portion 9a of the crankshaft 9 and the lumen pivot portion 12a of the roller 11 is set at a position which is left and right equally spaced from the axial center of the roller 11. It is.

An Oldham mechanism 13 is interposed between the end of the roller 11 on the side of the main bearing 6 and the portion of the main bearing 6. The Oldham mechanism 13 regulates the rotation of the roller 11.

From this, when the crankshaft 9 rotates, the crank portion 9a provided therein performs eccentric rotation, and the roller 11 pivotally supported on the outer peripheral surface of the crank portion 9a performs an eccentric movement. Eggplant

As the roller 11 rotates, the rolling contact portion of the outer peripheral wall of the roller 11 with the inner peripheral wall of the cylinder 5 gradually moves in the circumferential direction of the cylinder 5.

On the outer peripheral surface of the roller 11, a sub bearing 8 is provided.
A spiral groove 14 having a gradually smaller pitch is provided from the mounting end to the main bearing 6 mounting end.
A spiral blade 15 is wound around 4 so that it can freely enter and exit.

The blade 15 is made of a highly slippery material such as a fluorine resin, and has an inner diameter larger than an outer diameter of the roller 11. That is, the blade 15
Is forcibly fitted in the spiral groove 14 with the diameter reduced, and as a result, the outer peripheral surface of the blade 15 is always elastically attached to the inner peripheral wall of the cylinder 5 while the roller 11 is incorporated in the cylinder 5 together with the roller 11. It swells and deforms so as to abut.

As described above, when the roller 11 pivots and the rolling contact position with respect to the cylinder 5 moves, as the rolling contact portion approaches, the blade 15 moves into the spiral groove 14.
At the rolling contact position, the outer peripheral surface of the blade 15 is
Completely identical to the outer peripheral surface.

Conversely, when the rolling contact portion passes, the blade 15 protrudes from the spiral groove 14 according to the distance therefrom,
The rolling contact portion is a portion that faces 180 ° via the axis b,
The protruding length of the blade 15 is maximized. After that, since it approaches the rolling contact portion again, the above-described operation is achieved.

A sectional view of the cylinder 5 and the roller 11 taken along the radial direction shows that the roller 11 is accommodated eccentrically with respect to the cylinder 5 and a part of the peripheral surface of the roller is in rolling contact with the cylinder. Therefore, a crescent-shaped space is formed between the cylinder 5 and the roller 11.

Looking at the space along the axial direction, the blade 15 is wound around the spiral groove 14 of the roller 11 and the outer peripheral surface thereof is in rolling contact with the inner peripheral wall of the cylinder 5.
The roller 11 and the cylinder 5 are partitioned by the blade 15 into a plurality of spaces.

These partitioned spaces are referred to as compression chambers 16. The volume of each compression chamber 16 gradually decreases from the end of the sub bearing 8 to the end of the main bearing 6 from the setting of the spiral groove 14.

On the other hand, the lid plate 1 constituting the closed case 1
c, a suction pipe 17 is provided therethrough,
The discharge pipe 18 is connected to this vicinity. The suction pipe 17 is connected to an evaporator that forms a refrigeration cycle, and the discharge pipe 18 is connected to a condenser that also forms a refrigeration cycle. A suction pipe 17 penetrating the closed case cover plate 1c (both not shown) is connected to a connection portion 8a provided on the sub bearing 8 inside the closed case 1. The connecting portion 8a is open at the joint surface of the sub bearing 8 with the cylinder 5. The discharge pipe 18 has its open end facing the closed case 1.

A concave portion 19 is provided at the flange 5b of the cylinder 5 facing the opposite end of the sub-bearing connecting portion 8a, so that gas introduced from the suction pipe 17 can be temporarily stored.

A concave portion (not shown) for a gas passage is provided at one end of the roller 11. The concave portion for the gas passage faces the concave portion 19 provided in the cylinder 5 irrespective of the position of the roller 11 that makes a revolving motion.

Therefore, the gas passage recessed portion and the recessed portion 19 form a large-capacity buffer portion 21 for temporarily storing the gas introduced from the suction pipe 17.

A discharge hole 24 is provided on the side of the main bearing 6.
Is provided. Through this discharge hole 24, the cylinder 5
And the roller 11 side end space and the electric motor unit 4 side space are communicated.

From the setting of the pitch of the spiral groove 14, the compression chamber 16 on the side where the buffer section 21 is provided becomes the suction section A, and the compression chamber 16 on the side where the discharge hole 24 is provided on the opposite side. It becomes the discharge section B.

Then, a first space 25 surrounded by the main bearing 6, the crankshaft 9 and the rollers 11 is provided.
Is formed. A second space 26 surrounded by the sub bearing 8, the crankshaft 9 and the roller 11 is formed.

A guide hole 28 is provided from the end surface of the crankshaft 9 on the side of the sub-bearing 8 to the middle of the pivotal portion of the main bearing 6 and along the axis of the crankshaft. The open end of the guide hole 28 and the open end of the shaft pivot of the sub-bearing 8 are closed by a closing plate 30 attached to the sub-bearing end face via a fixing tool 29.

The guide hole 28 and the outer peripheral surface of the crankshaft 9 are connected by a plurality of oil holes described later. That is, the first oil hole 31 is provided at a portion communicating with the first space portion 25. The second oil hole 32 is provided in the second oil hole 32.
Is provided at a portion that communicates with the space 26.

The third oil hole 33 is opened to the pivot of the sub-bearing 8. The fourth oil hole 34 is opened on the peripheral surface of the crank 9 a and faces the second lumen pivot 12 a of the roller 11. The fifth oil hole 35 is opened to the pivot portion of the main bearing 6. An oil supply passage S including the third to fifth oil holes 33 to 35 is formed together with the guide hole 28.

An oil reservoir 37 for collecting lubricating oil is formed at the inner bottom of the closed case 1. An oil suction pipe 38 connected to the shaft pivot of the sub-bearing 8 is immersed in the lubricating oil of the oil sump 37.

The connecting portion of the oil suction pipe 38 communicates with the sliding surface of the crankshaft 9 which is the inner peripheral surface of the auxiliary bearing 8 pivotal support. An oil supply pump section 39 is provided at a crankshaft portion facing these.

A gas guide hole 43 is provided at the upper side of the figure in the flange 5a of the cylinder 5 which is press-fitted into the case body 1a, and the lower part of the oil sump 37 is immersed in the lubricating oil. An oil guide hole 44 is provided.

Each of the guide holes 43 and 44 is provided to penetrate both side surfaces of the flange 5a, and communicates with the inside of the sealed case 1 partitioned by the flange. That is, the gas guide hole 43 is for conducting and guiding the high-pressure gas discharged from the discharge portion B, and the oil guide hole 44 is for conducting and guiding the lubricating oil in the oil reservoir 37.

On the other hand, the electric motor unit 4 is provided with a rotor 45 fitted to a rotating shaft portion 9Z of the crankshaft 9 protruding from the main bearing 6, and the casing 45 with a predetermined gap from the outer peripheral surface of the rotor 45. And a stator 46 fitted to the inner peripheral surface of the main body 1a.

The balance weight 10 is attached to the crankshaft 9 in the following procedure. The balance weights 9b, 10 are usually formed to have a larger diameter than the lumen pivot 12a in order to ensure dynamic balance, and the balance weights 9b, 10 can be passed through the lumen pivot 12a of the roller 11. Can not. Therefore, the following procedure is required.

That is, the roller 11 is inserted from the right side of the crankshaft 9 in FIG. For this reason, the lumen pivot 12a of the roller 11 can be opposed to the crank 9a without passing through the balance weight 9b. On the other hand, after that, by fitting the balance weight 10 from the right side in FIG. 1 of the crankshaft 9, the balance weight 10 can be attached to a predetermined position without passing through the lumen pivot 12 of the roller 11.
Then, the balance weight 10 is fixed by the key 50 and the retaining ring 51.

The helical blade type fluid compressor constructed as described above operates as follows. That is,
The motor unit 4 is energized to rotate the crankshaft 9 integrally with the rotor 45. This crankshaft 9
Is transmitted to the roller 11 via the crank portion 9a.

That is, since the crank portion 9a is eccentrically provided and the lumen pivotal support portion 12a of the roller 11 is rotatably engaged with the crank portion 9a, the roller 11 is
Pressed by a. In addition, since the Oldham mechanism 13 interposed between the main bearing 6 and the roller 11 regulates the rotation of the roller 11, the roller 11 makes a revolving motion without rotating.

On the other hand, low-pressure refrigerant gas is sucked from the suction pipe 17 and temporarily stored in the buffer section 21 formed by the cylinder 5 and the roller 11. Then, it is guided to the compression chamber 16 on the suction part A side.

With the turning movement of the roller 11, the rolling contact position of the roller 11 with respect to the inner peripheral surface of the cylinder 5 gradually moves in the circumferential direction, and the blade 15 moves in and out of the spiral groove 14. That is, the blade 15 moves in the radial direction of the roller 11.

The refrigerant gas guided to the compression chamber 16 on the suction section A side is sequentially transferred to the compression chamber 16 in the direction of the discharge section B in accordance with the turning movement of the roller 11 from where the blade 15 is formed in a spiral shape. Is done.

The pitch of the blades 15 is set so as to gradually decrease from the suction section A to the discharge section B. Since the volume of the compression chamber 16 partitioned by the blades 15 is sequentially reduced, the refrigerant gas flows into the compression chamber. Are sequentially transferred, and the pressure is increased to a predetermined pressure in the compression chamber closest to the discharge section B to increase the pressure.

The high-pressure gas is discharged from the compression chamber 16 of the discharge portion B and fills the first space portion 25 before the main bearing 6
Is guided to a space on the side of the electric motor unit 4 through a discharge hole 24 provided in the motor. Then, the gas is guided to a space portion on the compression mechanism portion 3 side through a gas guide hole 43 provided in a flange portion 5a of the cylinder 5, and is filled.

The high-pressure gas is guided to the discharge pipe 18 from the space where the open end of the discharge pipe 18 faces.
From here it is led to the condenser. As described above, in the helical blade type compression mechanism section 3 of the present invention, the balance weights 9b, 9b, Since 10 is arranged, dynamic balance can be obtained. In addition, one balance weight 1
0 is formed by fitting to the crankshaft 9, so that the outer diameter of the balance weight 10 and the roller 12
It is not necessary to consider the inner diameter of the lumen pivot 12a. Therefore, assembling becomes possible even when the balance weight 10 is large, and dynamic balance can be completed by the balance weights 9b and 10. Therefore, vibration during operation of the fluid compressor can be extremely reduced.

On the other hand, since the balance weights 9 b and 10 are both disposed between the main bearing 6 and the sub-bearing 8, the bending of the crankshaft 9 generated when the balance weight is disposed on the electric motor unit 4 side. Can be prevented.

The relative movement of the balance weight 10 with respect to the crankshaft 9 in the circumferential direction is restricted by the key 50, and the movement of the balance weight 10 in the axial direction is restricted by the retaining ring 51. Movement during machine operation can be prevented, and dynamic balance can be maintained.

The present invention is not limited to the above embodiment. That is, in the above embodiment, the helical blade type fluid compressor has been described, but the invention may be applied to a rotary type fluid compressor. Further, instead of the balance weight 10, a balance weight in which a key is integrally formed may be used. In addition, it goes without saying that various modifications can be made without departing from the spirit of the present invention.

[0080]

According to the first aspect of the present invention, dynamic balance can be achieved, and weight balance and moment balance can be ensured. According to the invention described in claim 2, it is possible to prevent the crankshaft from bending.

According to the third aspect of the present invention, when the crankshaft is incorporated into the roller, the crankshaft can be easily inserted even if the roller has a small inner diameter portion such as a portion in contact with the crank portion. Can be.

According to the invention described in claim 4, the dynamic balance can be maintained even when the rotation is started. According to the fifth aspect of the present invention, it is possible to provide a helical blade type fluid compressor which facilitates the attachment of the balance weight and has good assemblability.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a fluid compressor according to an embodiment of the present invention.

FIG. 2 is a diagram showing a main part of the apparatus.

FIG. 3 is a longitudinal sectional view showing a conventional fluid compressor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Sealing case 3 ... Compression mechanism part 4 ... Electric motor part 5 ... Cylinder 6 ... Main bearing, 8 ... Sub bearing, 9 ... Crankshaft 9a ... Crank part, 9b, 10 ... Balance weight 11 ... Roller 12 ... Inner cavity part 12a ... Lumen pivot 13. Oldham mechanism 14. Spiral groove 15. Blade 16.

Claims (5)

[Claims] 1. A fluid compressor comprising a compression mechanism for compressing a fluid to be compressed introduced between said cylinder and said roller by revolving a roller eccentrically arranged in the cylinder, said compression mechanism comprising: And a crankshaft having a crank portion for rotating the roller in the cylinder. The crankshaft is provided with the crank portion in the axial direction of the crankshaft. A fluid compressor comprising two balance weights. 2. The crankshaft according to claim 1, wherein the crankshaft is supported by a main bearing and a sub-bearing, and the balance weight is disposed between the main bearing and the sub-bearing. Fluid compressor. 3. One of the balance weights is formed integrally with the crankshaft.
The fluid compressor according to claim 1, wherein the other balance weight is formed by fitting to the crankshaft. 4. The fluid compressor according to claim 3, wherein relative movement of the other balance weight with respect to the crankshaft in the circumferential direction and the axial direction is restricted. 5. The compression mechanism is provided with a spiral groove provided along the peripheral surface of the roller and formed at a pitch gradually reduced, and a space between the spiral groove and the cylinder which is fitted into and out of the spiral groove so as to freely come and go. A helical blade for partitioning into a plurality of compression chambers having a gradually decreasing volume, wherein the compressed fluid sucked into the compression chamber on the side where the pitch of the helical groove is large gradually increases in the spiral shape. 4. The fluid compressor according to claim 1, wherein the fluid is compressed while being transferred to a compression chamber on the side where the pitch of the groove is small.