JP2002188587A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary compressor provided with a bypass groove on a cylindrical inner face of a cylinder, capable of operating efficiently with small vibration and low noise over a wide scope from low rotation to high rotation of the compressor, and being advantageous from the viewpoint of cost. SOLUTION: In this rotary compressor constituted such that a compression part consists of a crank shaft having an eccentric shaft part for transmitting a rotation force of an electric motor to the compression part, the cylinder 8 having a suction port 6 and a discharge port 7 on the cylindrical inner face, an upper bearing and a lower bearing arranged at both ends in the axial direction of the cylinder 8 to support the crank shaft rotatably, an annular piston moving along the cylindrical inner face of the cylinder 8 and having an inner peripheral part fitted rotatably into the eccentric shaft part, and a vane 13 partitioning a compression chamber 14 formed by an outer peripheral face of the piston and the cylindrical inner face of the cylinder into a low pressure chamber communicated with the suction port 6 and a high pressure chamber communicated with the discharge port 7, the bypass groove 16 having a predetermined length is provided in the circumferential direction from the vicinity of the suction port 6 toward the discharge port 7 on the cylindrical inner face of the cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-cylinder rotary compressor, and more particularly, to a cylinder capable of operating efficiently with low vibration and low noise over a wide range from low rotation to high rotation of the compressor. Regarding the structure.

[0002]

2. Description of the Related Art Conventionally, rotary compressors having a one-cylinder structure and a two-cylinder structure have been generally used. As a one-cylinder rotary compressor which is advantageous in terms of cost, for example, there is one as shown in FIGS. In the figure, an electric motor 2 and a compression unit 3 driven by the electric motor 2 are arranged above and below in a closed container 1.

The compression section 3 includes a crankshaft 4 having an eccentric shaft section 5 for transmitting the rotational force of the electric motor 2 to the compression section 3, and a cylinder 8 having an intake port 6 and a discharge port 7 on the inner surface of the cylinder. An upper bearing 9 and a lower bearing 10 which are arranged at both ends in the axial direction of the cylinder 8 and rotatably support the crankshaft 4, and move along the inner surface of the cylinder of the cylinder 8, and the inner peripheral portion is eccentric. An annular piston 11 rotatably fitted to the shaft portion 5 and a vane 13 slidably fitted in a vane groove 12 provided in the cylinder 8 are provided. 6a communicates with the suction port 6,
Inhale low-pressure refrigerant from an accumulator (not shown),
This is a suction pipe for supplying to the compression section 3.

A compression chamber 14 is formed by the outer peripheral surface of the piston 11 and the inner surface of the cylinder of the cylinder 8,
13 is pressed against the piston 11 by a spring member 15 to partition the compression chamber 14 into a low-pressure chamber 9a communicating with the suction port 6 and a high-pressure chamber 9b communicating with the discharge port 7.

In the above configuration, the suction port 6a is connected to the suction port 6a.
The low-temperature and low-pressure refrigerant drawn into the low-pressure chamber 9a of the compression chamber 14 is compressed with the rotation of the piston 11, becomes high-temperature and high-pressure gas in the high-pressure chamber 9b, and is discharged from the discharge port 7. However, when the compressor is operated at a low speed, useless compression (over-compression) is performed. Therefore, in a one-cylinder rotary compressor, the torque applied to the electric motor 2 increases structurally,
The vibration of the compressor is so large that the piping system may be damaged, which makes the operation difficult. As a countermeasure, there is a torque control technique for reducing vibration by sending a voltage input to an electric motor in consideration of torque fluctuation to a compressor. However, this torque control is disadvantageous in cost because the control circuit is complicated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in a one-cylinder rotary compressor, a bypass groove is provided in a cylinder inner surface of a cylinder so that the compressor rotates from a low rotation to a high rotation. Wide range, low vibration,
It is an object of the present invention to provide a rotary compressor that can be operated efficiently with low noise and is advantageous in cost.

[0007]

Means for Solving the Problems The present invention has been made to solve the above-mentioned problems, and comprises an electric motor,
A compression unit driven by the electric motor is arranged, and the compression unit includes a crankshaft having an eccentric shaft for transmitting the rotational force of the electric motor to the compression unit, and a suction port and a discharge port on the inner surface of the cylinder. A cylinder, upper and lower bearings disposed at both axial ends of the cylinder for rotatably supporting the crankshaft, and moving along the inner surface of the cylinder of the cylinder, and the inner peripheral portion rotates about the eccentric shaft portion. A vane that divides a compression chamber formed by an annular piston that is fitted and an outer peripheral surface of the piston and a cylindrical inner surface of the cylinder into a low-pressure chamber communicating with the suction port and a high-pressure chamber communicating with the discharge port. In the rotary compressor having the configuration described above, a bypass groove having a predetermined length is provided on the inner surface of the cylinder in the circumferential direction from the vicinity of the suction port toward the discharge port.

[0008] Further, the length of the bypass groove is set to be within a half circumference of the inner surface of the cylinder.

[0009] Further, the starting portion of the bypass groove communicates with the suction port.

The bypass groove may be formed so that the depth of the bypass groove is uniform over the entire length, or the depth of the bypass port is deep and the depth of the bypass groove is shallow toward the discharge port.

The width of the bypass groove may be uniform over its entire length, or may be wider at the suction port side and narrower toward the discharge port side.

Further, the bypass groove is composed of a plurality of bypass grooves.

Further, the bypass groove is formed so as to be horizontal or inclined upward toward the discharge port.

The cross-sectional shape of the bypass groove may be an arc,
It has a rectangular, trapezoidal or V-shaped configuration.

Further, at least one of the upper and lower end surfaces of the inner surface of the cylinder is provided with a chamfer in the circumferential direction from the vicinity of the suction port toward the discharge port.

The chamfered portion is formed so that the depth of the chamfered portion is uniform over the entire length or the depth of the suction port is deep and the depth of the chamfer is reduced toward the discharge port.

Further, the chamfered portion is constituted by a plurality of stages.

Further, the chamfered portion is formed in an arc shape, a C chamfer or a tapered chamfer.

An electric motor and a compression unit driven by the electric motor are arranged in the closed container, and the compression unit is formed of a crank having an eccentric shaft for transmitting the rotational force of the electric motor to the compression unit. A shaft, a cylinder having a suction port and a discharge port on the inner surface of the cylinder, an upper bearing and a lower bearing which are arranged at both axial ends of the cylinder and rotatably support the crankshaft, and along the inner surface of the cylinder of the cylinder. Move,
An annular piston whose inner peripheral portion is rotatably fitted to the eccentric shaft portion; a compression chamber formed by an outer peripheral surface of the piston and a cylindrical inner surface of the cylinder; a low-pressure chamber communicating with the suction port; In a rotary compressor constituted by a vane partitioning into a high-pressure chamber communicating with a discharge port, one or both of the upper bearing and the lower bearing, on the cylinder-side thrust receiving surface, from the vicinity of the suction port. The bypass groove is provided circumferentially or linearly toward the discharge port.

[0020]

Embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic sectional view of a rotary compressor according to the present invention and a conventional example, and FIG.
FIG. 3 is an enlarged perspective view of an essential part showing one embodiment of the present invention. In the figure, an electric motor 2 and a compression unit 3 driven by the electric motor 2 are arranged above and below in a closed container 1.

The compression section 3 includes a crankshaft 4 having an eccentric shaft section 5 for transmitting the rotational force of the electric motor 2 to the compression section 3, and a cylinder 8 having an intake port 6 and a discharge port 7 on the inner surface of the cylinder. An upper bearing 9 and a lower bearing 10 which are arranged at both ends in the axial direction of the cylinder 8 and rotatably support the crankshaft 4, and which move along the inner surface of the cylinder of the cylinder 8 so that the inner peripheral portion is eccentric. An annular piston 11 rotatably fitted to the shaft portion 5 and a vane 13 slidably fitted in a vane groove 12 provided in the cylinder 8 are provided. 6a communicates with the suction port 6,
Inhale low-pressure refrigerant from an accumulator (not shown),
This is a suction pipe for supplying to the compression section 3.

The outer peripheral surface of the piston 11 and the inner surface of the cylinder of the cylinder 8 form a compression chamber 14.
13 is pressed against the piston 11 by a spring member 15 to allow the compression chamber 14 to communicate with the suction port 6 in a low-pressure chamber 14a.
And a high-pressure chamber 14b communicating with the discharge port 7.

A bypass groove 16 having a length within a half circumference (180 degrees) of the inner surface of the cylinder is formed on the inner surface of the cylinder 8 in the circumferential direction near the inlet 6 or from the inlet 6 toward the outlet. The configuration is provided. The bypass groove 16
As shown in FIGS. 4A and 4B, is formed such that the groove depth a is uniform over the entire length, or is deeper on the suction port 6 side and shallower on the discharge port 7 side. .

The bypass groove 16 is formed as shown in FIG.
As shown in (B), the groove width b is formed so as to be uniform over the entire length or to be wider on the suction port 6 side and narrower toward the discharge port 7 side. The bypass groove 16 may be formed of a plurality of grooves as shown in FIG. 6C, or may be inclined upward toward the discharge port 6 as shown in FIG. 6D. Is formed. Also,
As shown in FIGS. 5 (A), (B), (C) and (D), the bypass groove 16 has a configuration in which its cross section is formed in an arc, a rectangle, a trapezoid or a V-shape.

In the above configuration, a half of the inner surface of the cylinder (180) is formed on the inner surface of the cylinder 8 forming the compression chamber 14 in the vicinity of the suction port 6 or in the circumferential direction from the suction port 6 toward the discharge port. With the configuration in which the bypass groove 16 having a length of not more than (degrees) is provided, when the compressor is operating at a low speed, from the start of compression until the crankshaft 4 (also the piston 11) rotates about 1/2 rotation. The suction refrigerant in the compression chamber 14 is actively leaked to the suction port 6 side through the bypass groove 16 to reduce unnecessary work (overcompression) and secure a necessary volume ratio, as shown in FIG. As described above, the vibration is reduced by reducing the torque fluctuation applied to the electric motor 2. During medium to high speed operation of the compressor, the leakage of the refrigerant per unit time is reduced, so that the volume ratio as designed can be secured.

FIG. 8 shows another embodiment of the present invention, in which at least one of the upper and lower end faces of the inner surface of the cylinder 8 is provided from the vicinity of the suction port 6 to the discharge port 7.
With the configuration in which the chamfered portion 17 is provided in the circumferential direction toward, the same effect as described above can be obtained. The chamfer 17
9A is formed over the entire length, or the suction port 6 side is formed deeper and shallower toward the discharge port as shown in FIG. 9A, or two steps as shown in FIG. 9B. May be configured. 10 (A), (B), (C)
As shown in the figure, the chamfered portion 17 is formed in an arc shape, a C chamfer or a tapered chamfer.

FIG. 11 shows still another embodiment according to the present invention, in which one of the upper bearing 9 and the lower bearing 10 is used.
Alternatively, both of the thrust receiving surfaces 10a on the cylinder 8 side
In addition, the same effect as described above can be obtained by providing a configuration in which the bypass groove 18 is provided circumferentially or linearly from the vicinity of the suction port 6 toward the discharge port 7.

As described above, when the compressor is operating at a low speed, the refrigerant sucked in the compression chamber 14 from the start of compression until the crankshaft 4 rotates about half of the time passes through the bypass groove 16. Actively leaks to the suction port 6 side through
By reducing wasteful work (overcompression), securing the required volume ratio, and reducing torque fluctuations on the electric motor 2, vibration can be reduced, and the compressor can be operated from low to high rotation speeds. A rotary compressor that can operate efficiently with low vibration and low noise over a wide range.

[0029]

As described above, in the present invention, low vibration, low vibration,
A rotary compressor that can operate efficiently with low noise.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a rotary compressor according to the present invention and a conventional example.

FIG. 2 is a sectional view taken along the line XX ′ of FIG. 1 according to the present invention;

FIG. 3 is an enlarged perspective view of a main part showing one embodiment of the present invention.

FIG. 4 is a sectional view showing a groove depth of a bypass groove of the present invention;
(A) shows the case where the thickness is uniform, and (B) shows the case where the width is changed.

5A and 5B show cross-sectional shapes of a bypass groove of the present invention, wherein FIG. 5A is an arc, FIG. 5B is a rectangle, FIG. 5C is a trapezoid, and FIG.
Is V-shaped.

FIG. 6 is a sectional view showing a groove width of a bypass groove according to the present invention;
(A) when uniform, (B) when the tip narrows,
(C) shows the case where there are a plurality of grooves, and (D) shows the case where the tip is inclined upward.

FIG. 7 is a diagram showing a relationship between a crank angle and a torque according to the present invention and a conventional example.

FIG. 8 is a perspective view showing another embodiment according to the present invention.

FIG. 9 is a sectional view showing the depth of the chamfered portion of the present invention;
(A) shows the case where the tip becomes shallow, and (B) shows the case of a two-stage configuration.

10A and 10B are cross-sectional shapes of a chamfered portion of the present invention, wherein FIG. 10A is a C-chamfer, FIG. 10B is an arc shape, and FIG. 10C is a tapered chamfer.

FIG. 11 is a perspective view showing still another embodiment according to the present invention.

FIG. 12 is a cross-sectional view taken along the line XX ′ of FIG. 1 according to a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Closed container 2 Electric motor 3 Compression part 4 Crankshaft 5 Eccentric shaft part 6 Suction port 6a Suction pipe 7 Discharge port 8 Cylinder 9 Upper bearing 10 Lower bearing 11 Piston 12 Vane groove 13 Vane 14 Compression chamber 15 Spring member 16, 18 Bypass groove 17 Chamfer

Claims (13)

[Claims] An electric motor and a compression unit driven by the electric motor are arranged in a closed container, and the compression unit is a crank having an eccentric shaft for transmitting the rotational force of the electric motor to the compression unit. A shaft, a cylinder having a suction port and a discharge port on the inner surface of the cylinder, an upper bearing and a lower bearing which are arranged at both axial ends of the cylinder and rotatably support the crankshaft, and along the inner surface of the cylinder of the cylinder. A low-pressure passage through the suction port, wherein the compression chamber formed by moving and having an inner peripheral portion rotatably fitted to the eccentric shaft portion and an outer peripheral surface of the piston and a cylindrical inner surface of the cylinder is formed. A rotary compressor comprising a chamber and a vane partitioning into a high-pressure chamber communicating with the discharge port. of Rotary compressor characterized by comprising providing a bypass groove. 2. The rotary compressor according to claim 1, wherein the length of the bypass groove is set to be within a half circumference of the inner surface of the cylinder. 3. The rotary compressor according to claim 1, wherein a start portion of said bypass groove communicates with said suction port. 4. The rotary according to claim 1, wherein the depth of the bypass groove is uniform over the entire length, or the bypass groove is formed so as to be deep on the suction port side and shallow toward the discharge port side. Compressor. 5. The rotary compression apparatus according to claim 1, wherein the width of the bypass groove is uniform over the entire length, or the width of the bypass groove is widened toward the suction port and narrowed toward the discharge port. Machine. 6. The rotary compressor according to claim 1, wherein said bypass groove comprises a plurality of bypass grooves. 7. The rotary compressor according to claim 1, wherein said bypass groove is formed so as to be horizontal or inclined upward toward said discharge port. 8. The rotary compressor according to claim 1, wherein a cross-sectional shape of said bypass groove is formed in an arc, a rectangle, a trapezoid, or a V-shape. 9. The method according to claim 1, wherein at least one of the upper and lower end surfaces of the inner surface of the cylinder is chamfered in a circumferential direction from the vicinity of the suction port toward the discharge port. Rotary compressor. 10. The apparatus according to claim 9, wherein the chamfered portion is formed so that the depth thereof is uniform over the entire length, or the chamfered portion is deeper on the suction port side and shallower toward the discharge port.
The rotary compressor as described in the above. 11. The rotary compressor according to claim 9, wherein said chamfered portion is constituted by a plurality of stages. 12. The rotary compressor according to claim 9, wherein said chamfered portion is formed in an arc shape, a C chamfer or a tapered chamfer. 13. A crank having an electric motor and a compression section driven by the electric motor in an airtight container, the crank having an eccentric shaft for transmitting the rotational force of the electric motor to the compression section. A shaft, a cylinder having a suction port and a discharge port on the inner surface of the cylinder, an upper bearing and a lower bearing which are arranged at both axial ends of the cylinder and rotatably support the crankshaft, and along the inner surface of the cylinder of the cylinder. A low-pressure passage through the suction port, wherein the compression chamber formed by moving and having an inner peripheral portion rotatably fitted to the eccentric shaft portion and an outer peripheral surface of the piston and a cylindrical inner surface of the cylinder is formed. In a rotary compressor constituted by a chamber and a vane partitioning into a high-pressure chamber communicating with the discharge port, in one or both of the upper bearing and the lower bearing, the cylinder-side thrust receiving surface has a front surface. A rotary compressor having a bypass groove provided circumferentially or linearly from the vicinity of the suction port toward the discharge port.