JPH11107969A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively and inexpensively restrain generation of vibration in the rotating direction while minimizing change of design of a conventional product. SOLUTION: A vibration absorbing part is composed of an arm 41 made of a resilient member which is shorter than the diameter of a closed casing 1 weights 42 fixed to opposite ends of the arm 41, a fixing member 43 for fixing the am 41 to a bottom part 2b, and the like. Further, the vibration absorbing part 40 is fixed to the bottom wall 2b having its center part recessed outward of the closed casing 1 in a bowl-like shape so as to enhance the sound suppression effect, via the fixing member 43. With this arrangement, it is possible to effectively and inexpensively restrain generation of vibration in the rotating direction while minimize the change of design of a conventional product.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor capable of absorbing vibration in a rotating direction generated when a roller of a rotary compressor is rotated at a low speed and suppressing the generation of the vibration. .

[0002]

2. Description of the Related Art Conventionally, rotary compressors which can reduce the amount of eccentricity of a crank and can be reduced in size as compared with reciprocating compressors are often used in air conditioners and the like.

FIG. 4 is a sectional view of a rotary compressor. The compressor includes a roller 19, a cylinder 13 for accommodating the roller 19, and a compression unit 4 including a not-shown vane or the like, which abuts on a peripheral surface of the roller 19 to partition the inside of the cylinder 13 into a suction side and a discharge side. The rotor 34 is fixed to the shaft 18 of the roller 19, and has a motor 3 and the like for applying a rotating power to the roller 19.

As described above, the motor 3 is composed of the rotor 34 and the winding portion 35 disposed on the outer peripheral surface side thereof. The motor 3 has a reduced size, energy saving, and easier control than an AC motor. For this reason, DC motors tend to be used frequently in recent years.

Then, the shaft 18 rotates and the roller 1 is rotated.
9 is eccentrically rotated, whereby the space volumes on the suction side and the discharge side are changed, and the refrigerant gas is compressed.

At this time, as the refrigerant gas is compressed and the pressure increases, the resistance to the rotation of the roller 19 also increases, so that the angular velocity of the roller 19 becomes non-uniform and the vibration in the rotation direction proportional to the rotation speed is reduced. Will occur.

The vibration generated when the roller 19 is rotating at a high speed is sufficiently higher than the natural frequency of the compressor, so that the compressor does not resonate, but is rotating at a low speed. Since the generated vibration is close to the natural frequency, it resonates or is in an excited state, and the vibration width becomes large, causing noise or the like.

In order to solve such a problem, two rollers are provided and their rotation phases are arranged so as to be shifted from each other by 180 degrees, thereby canceling the vibration generated at each roller to suppress the generation of the vibration. It has been known.

Also, there is known a technique in which when one roller is used, the torque of the motor is controlled, and at low speed rotation, the torque is increased to suppress the generation of vibration itself.

[0010]

However, when two rollers are provided, there is a problem that the volume of the compression section becomes large and the cost becomes high. In addition, leakage occurs from the compression space formed by the roller and the cylinder. Since the amount of refrigerant gas to be discharged is doubled by a simple calculation, when the compression space is small as in, for example, a small device such as a refrigerator, a large leakage amount causes fatal deterioration of characteristics.

On the other hand, when the torque control is performed, there is a problem that the control is complicated and the cost is high, and the input power is increased.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a rotary compressor which can effectively absorb the above-mentioned vibration at a low cost while minimizing a design change or the like of a conventional product. .

[0013]

Therefore, in order to solve the above-mentioned problems, the invention according to claim 1 is characterized in that the roller is eccentric inside a sealed case having upper and lower walls fixed to both ends of a cylindrical side wall. Occurs when a roller rotates at a low speed on at least one of an upper wall and a lower wall in a rotary compressor provided with a compression unit having a compression mechanism that compresses a refrigerant gas by rotating. A vibration absorbing part for absorbing vibration in the rotating direction is provided.

According to a second aspect of the present invention, the upper wall or the lower wall is formed so as to expand from the inside to the outside of the sealed case, and a space at a peripheral end thereof forms a dead space, and the dead space is utilized. And a vibration absorber is provided.

According to a third aspect of the present invention, the vibration absorbing portion is formed by an arm made of an elastic member and weights fixed to both ends of the arm so that the intermediate point of the arm coincides with the rotation axis of the roller. It is characterized by being fixed to the upper wall or the lower wall and being arranged so that the weight is located in the dead space.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a vertical sectional structure of the rotary compressor.

An upper wall 2a is fixed to the upper portion of the sealed case 1, and a bottom wall 2b is fixed to the bottom to seal the inside. A DC motor 3 and a compression unit 4 are provided inside the sealed case 1. Are press-fitted with their central axes parallel to the axis.

The upper wall 2a and the bottom wall 2 of the sealed case 1
b is formed in a bowl shape with a central portion rounded off on the outside of the closed case 1 in order to enhance the soundproofing effect. On the lower surface of the bottom wall 2b, a vibration absorber 4 for absorbing vibration of a predetermined frequency is provided.
0 is provided.

Further, a suction pipe 6, a discharge pipe 7, a power supply terminal 8 for the DC motor 3 and the like are fixed to the side wall 5 of the sealed case 1.

The compression section 4 includes a cylinder 13, a shaft 18
A roller 19 that rotates in the cylinder 13
A vane (not shown) that abuts against the peripheral surfaces of bearings 16 and 17 and a roller 19 that rotatably supports the shaft 18 to partition the inside of the cylinder 13 into a suction side and a discharge side, and biases the vane toward the roller 19. And a discharge muffler 24 disposed so as to cover the bottom of the bearing 17.

The DC motor 3 has a plurality of winding portions 35 inserted along the inner wall of the closed case 1 and a rotor 34 fixed to the shaft 18 by shrink fitting. Winding part 3
5 is supported by a fixing member at a central portion thereof to form a closed case 1.
It is fixed to. A plurality of magnetized members 33 are embedded in the rotor 34.

FIG. 2 shows a top view of the vibration absorbing section 40. The vibration absorber 40 supports an arm 41 made of an elastic member appropriately shorter than the diameter of the closed case 1, a weight 42 fixed to both ends of the arm 41, and a center portion of the arm 41, and connects the arm 41 to the bottom wall 2 b. Has a fixing member 43 and the like that are fixed to the base member.

The natural frequency of the compressor is usually 30 Hz.
However, since it depends on the design, it cannot be specified unconditionally. In addition, although the natural frequency is originally one, there is also a natural frequency which is unique to a place of interest in reality.

Therefore, the length and the like of the arm 41 in the vibration absorbing section 40 cannot be limited unconditionally, and it is necessary to set the arm 41 in accordance with the vibration frequency to be absorbed.

The vibration absorbing portion 40 is arranged such that the weight 42 is located in a dead space in a peripheral portion formed when the lower wall 2b is fixed to the side wall 5. Therefore, since the compressor can be mounted without changing the design, vibration can be prevented at low cost while avoiding an increase in the volume of the compression section.

In the above configuration, the refrigerant gas sucked into the cylinder 13 via the suction pipe 6 is compressed according to the rotation of the roller 19, and the vibration in the rotation direction accompanying the compression is absorbed by the vibration absorber 40.

Then, the compressed refrigerant gas is supplied to the bearing 17.
The discharge gas is discharged to the discharge muffler 24 through a discharge hole and a discharge valve (not shown) provided in the nozzle, so that the pulsating sound of the refrigerant gas is attenuated.

Thereafter, the gas is discharged into the space 28, and is supplied from the discharge pipe 7 to the refrigeration cycle (not shown) as a high-pressure refrigerant gas through the air gear 29 and the gap 30.

The refrigerant gas whose pulsation sound has been attenuated by the discharge muffler 24 contains a large amount of atomized oil droplets. The collected oil is collected in an oil sump 31.

The rotation speed of the roller is not uniform due to the pressure fluctuation of the refrigerant gas due to the compression, and vibration in the rotating direction is generated. However, the vibration causes the weight 42 to vibrate approximately 180 degrees out of phase. As a result, generation of vibration in the rotation direction is suppressed.

In the above description, the case where the vibration absorbing portion 40 is constituted by fixing the weight 42 to both ends of the arm 41 has been described, but the present invention is not limited to this.

For example, the vibration absorbing section 50 shown in FIG. 3 may have a structure in which a weight 52 is fixed to one end of an arm 51 and the other end is erected around the lower wall 2b. Of course, also in this case, it is important to provide a plurality of them so as to maintain symmetry.

[0033]

As described above, according to the first aspect of the present invention, at least one of the upper wall and the lower wall absorbs the vibration in the rotating direction generated when the roller rotates at a low speed. Since the vibration absorbing portion is provided, noise due to the vibration can be prevented, and the quality can be improved.

According to the second aspect of the present invention, the vibration absorber is disposed by utilizing the dead space of the upper wall or the lower wall in which the vibration absorbing part is disposed, so that the conventional compressor is not changed in design. A vibration absorbing portion can be provided, and vibration generated by low-speed operation can be absorbed at low cost while avoiding an increase in the volume of the compression portion.

According to the third aspect of the invention, the vibration absorbing portion is formed by the arm made of the elastic member and the weight fixed to both ends of the arm, and the compressor is provided in the dead space of the upper wall or the lower wall. Independent of the action of the compressor, the vibration absorber can be provided without changing the design of the conventional compressor, and it can be generated simply and at low cost by low-speed operation while avoiding an increase in the capacity of the compressor. Vibrations can be absorbed.

[Brief description of the drawings]

FIG. 1 is a vertical cross-sectional view of a rotary compressor having a vibration absorbing section applied to an embodiment of the present invention.

FIG. 2 is a top view of a vibration absorber.

FIG. 3 is a longitudinal sectional view of a rotary compressor provided with a vibration absorbing portion having another configuration applied to the description of the embodiment of the present invention.

FIG. 4 is a longitudinal sectional view of a rotary compressor applied to the description of the conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylindrical closed case 2a Upper wall 2b Lower wall 3 DC motor 4 Compressor 5 Side wall 13 Cylinder 18 Shaft 19 Roller 40, 50 Vibration absorber 41, 51 Arm 42, 52 Weight 43 Fixing member

Claims (3)

[Claims] 1. A compression section having a compression mechanism for compressing a refrigerant gas by eccentric rotation of a roller is provided inside a sealed case having upper and lower walls fixed to both ends of a cylindrical side wall. In the rotary compressor described above, it is preferable that at least one of the upper wall and the lower wall is provided with a vibration absorbing portion that absorbs vibration in a rotating direction generated when the roller rotates at a low speed. Features a rotary compressor. 2. The method according to claim 1, wherein the upper wall or the lower wall is formed so as to expand from the inside of the sealed case to the outside, and a peripheral end thereof is provided with a space depressed inside the sealed case.
The rotary compressor according to claim 1, wherein the vibration absorbing unit is provided by utilizing the space. 3. The vibration absorbing section has an arm made of an elastic member and weights fixed to both ends of the arm, and the midpoint of the arm coincides with the rotation axis of the roller. 3. The rotary compressor according to claim 2, wherein the compressor is fixed to an upper wall or a lower wall, and the weight is disposed at a peripheral end without contacting the upper wall or the lower wall.