JP2004092517A - Fluid machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a silent and reliable fluid machine never generating noise. <P>SOLUTION: This fluid machine has a helical mechanism part having a spiral blade for forming a working chamber between a roller and a cylinder. In this fluid machine, the clearance between the outside surface of the roller and the inside surface of the cylinder is minimized in a position opposed to the crank part of a crankshaft. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a helical fluid compressor that continuously compresses a fluid to be compressed in the axial direction of a cylinder, and more particularly to a fluid compressor that prevents contact between a roller and a cylinder due to swinging of the roller.
[0002]
[Prior art]
Rotary compressors other than reciprocating compressors are widely used as compressors for compressing fluids, and helical compressors employing helical blades in the compression mechanism are also being adopted.
[0003]
As shown in FIG. 3, the conventional helical compressor 31 has a cylinder 32, a roller 33 eccentrically arranged in the cylinder 32, and a working chamber 34 defined between the roller 33 and the cylinder 32. A helical mechanism 36 comprising a helical blade 35, a crankshaft 37 for eccentrically rotating the roller 33 in the cylinder 32, and a driving unit 38 for rotating the crankshaft 37. The roller 33 has a cylindrical shape whose outer diameter is always constant in the axial (longitudinal) direction, and the cylinder 32 also has a hollow cylindrical shape whose inner diameter is always constant in the axial direction. gap g ₀ between the cylinder periphery and are including a position opposed to the crank portion 37a, was constant over the entire length in the axial direction.
[0004]
Therefore, during the compression stroke, the rotational force of the drive unit is transmitted to the crank unit 37a via the crankshaft 37, and causes the roller 33 to eccentrically rotate (revolve). Due to the eccentric rotation of the roller 33, the roller 33 slides while being in contact with the inner peripheral surface of the cylinder 32, and revolves. Due to the eccentric rotation of the roller 33, each working chamber 34 formed by the blade 35 between the cylinder 32 and the roller 33 changes its volume so as to gradually decrease in volume while moving helically in the cylinder axis direction. In each of the compression chambers, the refrigerant sucked through the gas suction holes 39 due to the volume change is sequentially compressed to have a high pressure, and is discharged through the discharge holes 40.
[0005]
In such a compression stroke, since the roller 33 rotates eccentrically via the crank 37a of the crankshaft 37 and the roller crank 33a of the roller 33, the roller 33 slightly oscillates from a position facing the crank 37a. As the distance increases, the roller 33 and the cylinder 32 are more likely to come into contact with each other, which may cause noise. In addition, there is a possibility that adhesion may occur and the reliability may be reduced.
[0006]
[Problems to be solved by the invention]
Accordingly, there has been a demand for a fluid machine that is quiet and free of noise and has high reliability.
[0007]
The present invention has been made in consideration of the above circumstances, and has as its object to provide a quiet and highly reliable fluid machine without generating noise.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, according to one aspect of the present invention, a working chamber is defined between a cylinder, a roller eccentrically disposed in the cylinder and provided with a roller crank portion, and the roller and the cylinder. A helical mechanism having a spiral blade to be formed, a crankshaft provided with a crank portion for eccentrically rotating the roller in the cylinder via the roller crank portion, and a crankshaft for rotationally driving the crankshaft. A fluid machine having a drive unit and a bearing for supporting a crankshaft, wherein a gap between an outer peripheral surface of the roller and an inner peripheral surface of the cylinder is minimized at a position facing the crank unit. Is provided. As a result, a quiet and highly reliable fluid machine without noise is realized.
[0009]
In a preferred example, the roller has a maximum outer diameter at a portion facing the crank portion. Thereby, the contact between the roller and the cylinder is reliably prevented.
[0010]
In another preferred example, the outer diameter of the roller has a portion that gradually decreases in diameter as the distance from the portion facing the crank portion increases.
[0011]
In another preferred example, the fluid machine is a compressor, and a reduction ratio of an outer diameter of the roller is larger on a low pressure side than on a high pressure side. Thus, even in the case of gas compression in which unbalance is likely to occur between the high pressure side and the low pressure side, the gap between the roller and the cylinder is reliably prevented because the gap is maximized on the low pressure side where the swing width is large. .
[0012]
In another preferred example, the reduced diameter portion of the outer diameter of the roller is formed by tapering, and the taper Δr is such that the maximum clearance of the roller crank portion is Cmax, and the length of the roller crank portion is Cmax. When L, Δr ≧ Cmax / L.
[0013]
In another preferred example, the inner diameter of the cylinder is minimized at a portion corresponding to a crank portion. Thereby, the contact between the roller and the cylinder is reliably prevented.
[0014]
In another preferred example, the cylinder has a portion whose inner diameter gradually increases as the inner diameter increases away from a portion corresponding to the crank portion.
[0015]
In another preferred example, the fluid machine is a compressor, and an expansion ratio of an inner diameter of the cylinder is larger on a low pressure side than on a high pressure side. Thus, even in the case of gas compression in which unbalance is likely to occur between the high pressure side and the low pressure side, the gap between the roller and the cylinder is reliably prevented because the gap is maximized on the low pressure side where the swing width is large. .
[0016]
In another preferred example, the enlarged diameter portion of the inner diameter of the cylinder is formed by tapering, and the taper Δc is such that the maximum clearance of the roller crank portion is Cmax and the length of the roller crank portion is L. △ c ≧ Cmax / L.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a first embodiment of a fluid machine according to the present invention will be described with reference to the accompanying drawings.
[0018]
FIG. 1 is a longitudinal sectional view of a horizontal helical compressor as a first embodiment of a fluid machine according to the present invention.
[0019]
As shown in FIG. 1, a fluid compressor, for example, a horizontal helical compressor 1 has an electric motor unit 2 and a compression mechanism unit 4 driven by the electric motor unit 2 via a crankshaft 3. A support leg 5 is attached to the compression mechanism 4.
[0020]
The electric motor unit 2 comprises a motor stator 8 which forms a rotation driving means and is covered by a cover 7 made of an insulating material such as a synthetic resin, and a motor rotor 9 which rotates within the motor stator 8. From the motor rotor 9, the crankshaft 3 having the crank portion 3a on one side extends to the compression mechanism portion 4 side.
[0021]
On the other hand, the compression mechanism unit 4 includes a cylinder 11, a roller (rotating body) 12 which is mounted on the crankshaft 3 and is eccentrically disposed in the cylinder 11 and provided with a roller crank portion 12 a. A helical blade that forms a plurality of compression chambers 15 whose volume gradually decreases from the suction side where the suction pipe 13 communicates to the discharge side where the discharge pipe 14 communicates, along the axial direction of the cylinder 11. 16.
[0022]
The cylinder 11 has a hollow cylindrical shape whose inner diameter is always constant in the axial direction.
[0023]
On the other hand, the outer diameter of the roller 12 is constant at the opposing portion 12p opposing the crank portion 3a of the crankshaft 3, and as the roller 12 moves away from the opposing portion 12p to both sides, the diameter gradually decreases. The outer shape is substantially barrel-shaped. Therefore, the outer diameter of the roller 12 is maximum at the opposing portion 12p. The crank portion 3a is formed so as to be slightly deviated toward the high pressure side with respect to the center section of the cylinder 11.
[0024]
Further, when the fluid machine is a helical compressor as in the present embodiment, the diameter of the low pressure side of the roller 12 is reduced by a larger taper (diameter reduction ratio) than that of the high pressure side. When the taper Δr of the portion that is gradually reduced in diameter as it moves away from the opposing portion 12p (the reduced diameter portion) is Cmax where the maximum clearance of the roller crank portion 12a is L and the length of the roller crank portion 12a is L, △ It is preferable that r ≧ Cmax / L. If Δr <Cmax / L, the roller and the cylinder may come into contact with each other. The diameter of the roller is reduced by tapering.
[0025]
As described above, the inner diameter of the cylinder 11 is always constant in the axial direction, and the outer diameter of the roller 12 is formed so as to be maximum at the opposed portion 12p. The gap g between the surfaces is minimum at the opposing portion 12p, increases toward both sides, and maximizes at the low pressure (suction pipe 13) side. That is, it becomes maximum on the side of the crank portion 3a opposite to the bias.
[0026]
The blade 16 is housed in a blade groove 17 formed on the outer surface of the roller 12. The blade groove 17 has a substantially rectangular cross section, for example, and its groove pitch is temporarily set in the axial direction of the roller 12. It is formed to be small. Further, the blade 16 is restrained by the inner peripheral wall of the cylinder 11 by the eccentric rotational movement of the roller 12, and smoothly slides in and out of the blade groove 17.
[0027]
Both ends of the cylinder 11 are closed by a main bearing 18 and a sub bearing 19, and the main bearing 18 and the sub bearing 19 are screwed to the cylinder 11 by fastening bolts (not shown). Further, when the roller 12 performs eccentric rotational movement, a rotation preventing mechanism 20 is provided so as to revolve the roller 12 and prevent the roller 12 from rotating. Further, the crankshaft 3 is provided for cooling the electric motor section 2 and the compression mechanism section 4. A cooling fan 21 is provided.
[0028]
Next, the operation of the horizontal helical compressor according to the first embodiment will be described.
[0029]
When the electric motor section 2 of the horizontal helical compressor 1 as shown in FIG. 1 is energized, the electric motor section 2 is started, a rotating magnetic field is generated in the motor stator 8, and the motor rotor 9 is driven to rotate.
[0030]
The rotational force of the motor rotor 9 is transmitted to the crank portion 3a via the crankshaft 3, which is the output shaft, and causes the roller 12 to eccentrically rotate (revolve). Due to the eccentric rotation of the roller 12, the roller 12 slides while being in contact with the inner peripheral surface of the cylinder 11, and revolves. Due to the eccentric rotation of the roller 12, each compression chamber 15 formed by the blade 16 between the cylinder 11 and the roller 12 changes its volume such that the volume gradually decreases while moving helically in the cylinder axis direction. In each of the compression chambers 15, the refrigerant sucked through the suction pipe 13 due to a change in volume is sequentially compressed to have a high pressure, and is discharged through the discharge pipe 6.
[0031]
In the process of compressing the refrigerant as described above, since the roller 12 rotates eccentrically via the crank portion 3a of the crankshaft 3 and the crank portion 12a of the roller 12, the roller 12 slightly whirls. The gap between the cylinder and the inner peripheral surface of the cylinder increases with increasing distance from the opposing portion 12p to both sides, so that there is no contact between the roller and the cylinder, no noise is generated, and adhesion due to contact also occurs. And reliability is improved. Also, even in the case of gas compression in which the crank portion is biased, the gap is maximized on the low pressure side (the opposite side of the crank portion) where the swing width is large, so that the roller and the cylinder can be reliably connected. Contact is prevented.
[0032]
Further, a second embodiment of the fluid machine according to the present invention will be described.
[0033]
In the first embodiment, the roller gradually decreases in diameter as the roller moves away from the roller crank portion on both sides, and the outer shape is substantially barrel-shaped. The diameter gradually increases greatly away from the position corresponding to the crank portion on both sides, and the inner shape is substantially a drum shape.
[0034]
For example, as shown in FIG. 2, the inner diameter of the cylinder 11A is constant at the opposing portion 11Ap facing the crank portion 3Aa of the crankshaft 3A, and gradually increases as the distance from the opposing portion 11Ap to both sides increases. The inner shape (the shape of the cylinder) is substantially drum-shaped. The tapered portion Δc of the gradually reduced diameter portion at this time is represented by Δc where the maximum clearance of the roller crank portion 12Aa corresponding to the crank portion 3A of the crankshaft 3A is Cmax and the length of the roller crank portion is L. It is preferred that ≧ Cmax / L. On the other hand, the roller 12A has a cylindrical shape whose outer diameter is always constant in the axial direction. Other configurations are the same as those of the fluid machine shown in FIG.
[0035]
Therefore, the gap gA between the outer peripheral surface of the roller 12A and the inner peripheral surface of the cylinder 11A is minimum at the opposing portion 11Ap of the cylinder 11A, increases toward both sides, and maximizes at the low pressure (suction pipe 13A) side. As a result, there is no contact between the roller and the cylinder, no noise is generated, and no cohesion occurs due to the contact, so that the reliability is improved. Further, even in the case of gas compression, the gap is maximized on the low pressure side where the swing width is large, so that contact between the roller and the cylinder is reliably prevented.
[0036]
【The invention's effect】
ADVANTAGE OF THE INVENTION According to the fluid machine concerning this invention, a noise-free and quiet, highly reliable fluid machine can be provided.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a first embodiment of a fluid machine according to the present invention.
FIG. 2 is a longitudinal sectional view of a second embodiment of the fluid machine according to the present invention.
FIG. 3 is a longitudinal sectional view of a conventional fluid machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Horizontal helical compressor 2 Electric motor part 3 Crank shaft 3a Crank part 4 Compression mechanism part 5 Support leg 7 Cover 8 Motor stator 9 Motor rotor 11 Cylinder 12 Roller (rotating body)
12a Roller crank section 13 Suction pipe 14 Discharge pipe 15 Compression chamber 16 Blade 17 Blade groove 18 Main bearing 19 Secondary bearing 20 Rotation prevention mechanism 21 Cooling fan

Claims (9)

A helical mechanism comprising a cylinder, a roller eccentrically disposed in the cylinder and provided with a roller crank portion, and a helical blade defining a working chamber between the roller and the cylinder; In a fluid machine having a crankshaft provided with a crank portion for eccentrically rotating the roller in a cylinder via a roller crank portion, a driving portion for rotationally driving the crankshaft, and a bearing for supporting the crankshaft, A fluid machine wherein a gap between an outer peripheral surface of a roller and an inner peripheral surface of the cylinder is minimized at a position facing the crank portion. 2. The fluid machine according to claim 1, wherein the roller has a maximum outer diameter at a portion facing the crank portion. 3. 3. The fluid machine according to claim 2, wherein the outer diameter of the roller has a portion that gradually decreases in diameter as it moves away from a portion facing the crank portion. 4. The fluid machine according to claim 3, wherein the fluid machine is a compressor, and a reduction ratio of an outer diameter of the roller is formed larger on a low pressure side than on a high pressure side. 5. 5. The fluid machine according to claim 4, wherein the reduced diameter portion of the outer diameter of the roller is formed by tapering, and the taper Δr is such that the maximum clearance of the roller crank portion is Cmax, and the length of the roller crank portion is Is a fluid machine, wherein Δr ≧ Cmax / L. 2. The fluid machine according to claim 1, wherein the inner diameter of the cylinder is minimized at a portion corresponding to a crank portion. 3. 7. The fluid machine according to claim 6, wherein the cylinder has a portion whose inner diameter gradually increases as a distance from a portion corresponding to a crank portion increases. 8. The fluid machine according to claim 7, wherein the fluid machine is a compressor, and an expansion ratio of an inner diameter of the cylinder is formed larger on a low pressure side than on a high pressure side. 9. The fluid machine according to claim 8, wherein the enlarged diameter portion of the inner diameter of the cylinder is formed by taper processing, and the taper Δc is such that the maximum clearance of the roller crank portion is Cmax and the length of the roller crank portion is Cmax. A fluid machine characterized by the following equation, where △ c ≧ Cmax / L.

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