JPH02248666A - Vibration damping device of rotary compressor - Google Patents

Abstract

PURPOSE:To obtain a sufficient vibration damping effect even if the rotating frequency is changed by fixing one end part of a tension coil spring having arm parts extending at right angles to the winding central axis from the both end parts of the winding to a fixture for a sealed case having a compressing element part and an electric motor part contained therein, and the other end part to an inertial body. CONSTITUTION:A sealed case 2 is vibrated by the operation of a compressor, but by vibrating the inertial body 15 of a dynamic vibration reducer 14 in the opposite phase to the vibration of the sealed case 2, the vibration of the sealed case 2 is damped. A connecting part 16 is formed of a tension coil spring having initial tension and arm parts 16a, 16b. When a space is formed between windings, bending rigidity is changed, and the peak width of the natural vibration of the dynamic vibration reducer 14 is widened, causing damping effect. Therefore, the peak width of the maximum damping frequency is widened, and vibration damping effect can be obtained in a wide frequency band. By fixing the protruding part 17a of a fixture 17 and the projection part 15a of the inertial body 15 to both end parts 16a, 16c of the connecting part 16, the natural frequency of the dynamic vibration reducer 14 can be stabilized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vibration damping device for a rotary compressor used in refrigeration equipment and the like.

BACKGROUND OF THE INVENTION In recent years, compressors used in refrigeration equipment, etc. have shifted from reciprocating type to rotary type from the viewpoint of energy and space saving, and beam vibration absorbers have been used as vibration damping devices for rotary type compressors. It is used. As conventional technology, for example,
As shown in Japanese Patent Publication No. 5B-55486,
There is a vibration damping structure for rotary hermetic electric compressors.

An example of the vibration damping structure of the conventional rotary compressor mentioned above will be described below with reference to one drawing.

FIG. 4 is a partial cross-section of a conventional rotary compressor.

In the figure, 1 is a rotary compressor, and 2 is a closed case. 3 is a stator of the motor, which is fixed to the sealed case 2 by shrink fitting. 4 is a rotor of the motor, which is connected and fixed to the crankshaft 6 by shrink fitting. A piston 6 is rotatably fixed to the eccentric portion of the crankshaft 5. 7 is a cylinder with lower bearings 8 at both ends. An upper bearing 9 is provided, and the outer peripheral portion is welded and fixed to the sealed case 2. Reference numeral 1o denotes a discharge cover, which is press-fitted and fixed to the upper bearing 9. Reference numeral 11 designates a dynamic vibration absorber, which includes an inertial body 12 and a shaft-shaped connecting portion 1 with this inertial body 12 provided at an end 13a.
3, and the other end 13b of the connecting portion 13 is fixed perpendicularly to the wall surface of the sealed case 2 by resistance welding. Further, the dynamic vibration absorber 11 is a rotary compressor 1.
The maximum damping frequency caused by the coupling of the natural vibration of the support system of the rotary compressor 1 itself due to the support and fixation of the rotary compressor 1 and the first-order natural vibration of the dynamic vibration absorber 11 is the maximum damping frequency of the rotary compressor 1. The inertial body 12 is adjusted so as to almost match the rotation frequency.
weight, shape, and length of the connecting portion 13.

Adjusting the diameter of the cross section.

The operation of the vibration damping device for a rotary compressor configured as described above will be described below.

When compressing the refrigerant in the cylinder T, the pressure in the cylinder 7 fluctuates greatly during one revolution of the crankshaft, causing a fluctuation in the angular velocity of the rotation of the crankshaft 5, which causes a force to be exerted on the cylinder 7 etc. as a reaction. receive. This causes vibrations in the rotational direction around the axis of the crankshaft 6, causing the sealed case 2 to vibrate greatly. However, by adjusting the natural frequency so that the maximum damping frequency almost matches the rotational frequency of the rotary compressor 10, the inertial body 12 of the dynamic vibration absorber 11 installed in the sealed case 2 has a phase opposite to the vibration of the sealed case 2. By vibrating, the dynamic vibration reducer 11 supplies a reaction torque to the closed case 2 via the connecting part 13 of the dynamic vibration absorber 11 at the location where it is installed in the closed case 72,
It dampens vibrations.

Problem to be Solved by the Invention However, in the above configuration, since the peak (Q value) of the natural vibration of the dynamic vibration absorber 11 is sharp, the maximum The peak of the attenuation frequency (Q value) also becomes sharper. Therefore, when the maximum damping frequency and the rotational frequency of the rotary compressor 10 match, the damping effect is extremely large.
Due to changes in the natural vibration due to manufacturing variations, etc., the maximum damping frequency caused by coupling with the natural vibration of the support system of the rotary compressor 1 itself changes, and the maximum damping frequency and 10 revolutions of the rotary compressor 1 change. When the frequency difference between the two frequencies becomes large, the vibration damping effect becomes insufficient.

Furthermore, stress is concentrated on the end portion 13b of the connecting portion 13 due to the deformation of the connecting portion 13, so that it may break due to fatigue caused by vibration or impact.

In view of the above-mentioned problems, the present invention prevents the vibration damping effect from decreasing due to fluctuations in the rotational frequency of a rotary compressor, manufacturing variations, etc., and prevents damage to the dynamic vibration absorber due to fatigue caused by vibration or impact. It is.

Means for Solving the Problems In order to solve the above problems, a vibration damping device for a rotary compressor according to the present invention provides a vibration damping device for a rotary compressor, which has arms extending from both ends of the winding in a direction substantially perpendicular to the winding central axis. It has a connecting part made of a coil spring, a cylindrical protrusion that is inserted and fixed to one end of the winding of this connecting part, and an arm extending from the end of this winding is fixed, and the compression element part or compression The winding comprises a fixture fixed to a sealed case in which the element part and the electric motor part are fixedly housed, and a cylindrical protrusion inserted and fixed to the other end of the winding of the connecting part. It is equipped with an inertial body with a fixed side part extending from the end of the body.

Effect: With the above-described configuration, the present invention absorbs vibrations generated during operation of a rotary compressor by causing a dynamic vibration absorber fixed to the rotary compressor main body to vibrate in an opposite phase to the vibrations of the rotary compressor. By supplying a reaction torque to the mold compressor and attenuating it, and by using a tension coil spring as the connection between the sealed case and the inertial body, vibrations and shocks at the end of the connection that is fixed to the sealed case are damped. In addition to reducing the stress caused by deformation that occurs, the connecting part is a tension coil spring and has an initial tension, so the bending rigidity of the connecting part varies depending on the amount of deformation of the connecting part, and it has a damping effect against vibration. By inserting and fixing the cylindrical projections provided on the fixture and the cylindrical projections provided on the inertial body at both ends of the connection part, the winding can be tightly attached even at the ends of the connection part. , stable bending rigidity of the connecting part can be obtained, and furthermore, by fixing the arms provided at both ends of the connecting part to the fixture and the inertial body, the connecting part, the fixture, and the inertial body can be firmly fixed. .

EXAMPLE An example of the present invention will be described below with reference to the drawings. Incidentally, in order to avoid duplication of explanation, the same parts as in the conventional example are given the same reference numerals and the explanation will be omitted.

1 to 3 show an embodiment of a vibration damping device for a rotary compressor according to the present invention.

In the figure, reference numeral 14 denotes a dynamic vibration absorber, which is composed of an inertial body 16, a connecting portion 16 made of a tight tension coil spring having an initial tension, and a fixture 17.

15a is a cylindrical protrusion provided on the inertial body 16;
7a is a cylindrical protrusion provided on the fixture 17.

The fixture 17 is fixed to the sealed case 2 by welding.

The protrusion 17a of the fixture 17 is press-fitted into the end 16a of the connecting portion 16, and a hook-shaped arm 16b extending from the end 16a in a direction substantially perpendicular to the winding center axis 16e is inserted and fixed with a bolt 18. As a result, it is fixed to the fixture 17.

Furthermore, the inertia body 16 is attached to the other end 16c of the connecting portion 16.
It is fixed to the fixture 17 by press-fitting and inserting the protrusion 15a, and further inserting and fixing the hook-shaped arm 16d extending from the end 16a in a direction substantially perpendicular to the winding central axis 16e using the port 19.

The winding center axis 16e of the connecting portion 160 is perpendicular to the rotating shaft 20.

Furthermore, the dynamic vibration absorber 14 is connected to the connecting portion 16 so that the maximum damping frequency generated by achieving the natural vibration of the support system of the rotary compressor and the natural vibration of the dynamic vibration absorber 14 almost matches the rotational frequency of the compressor 1. The shape of the inertial body 16 and the weight and shape of the inertial body 16 are adjusted.

The operation of the vibration damping device for a rotary compressor configured as described above will be described below.

When compressing the refrigerant in cylinder 7, crank shirt)
As the pressure inside the cylinder T fluctuates greatly during one rotation of the crankshaft 6a, the angular velocity of the rotation of the crankshaft 6a fluctuates, and as a reaction, a force is applied to the cylinder 7 and the like. Therefore, vibration occurs in the rotational direction around the axis of the crank shirt 6a, causing the sealed case 2 to vibrate greatly. At this time, the maximum damping frequency generated by achieving the natural vibration of the dynamic vibration absorber 14 installed in the sealed case 2 and the natural vibration of the support system of the rotary compressor 1 itself is set to approximately match the rotational frequency of the rotary compressor 1. Because of this adjustment, the inertial body 16 of the dynamic vibration absorber 14 vibrates in the opposite phase to the vibration of the sealed case 2. Therefore, a reaction torque is supplied to the sealed case 2 via the connecting portion 16 of the dynamic vibration absorber 14 and the fixture 17 fixed to the sealed case 2, thereby damping the vibration of the sealed case 2.

Furthermore, by using a tension coil spring as the connecting portion 16, the stress at the fixed end 1sd for the same displacement is smaller than that of a beam made of the same material and the same wire diameter, and fatigue due to vibration and stress due to impact can be reduced. Breakage of the fixed end 16d due to vibration or impact can be prevented, and the reliability of the dynamic vibration absorber 14 can be improved.

Furthermore, by using the connecting portion 16 as a tension coil spring having an initial tension, the connecting portion 16 undergoes a large amount of deformation in the bending direction during one cycle of vibration, and when a gap occurs between the windings, the bending rigidity decreases. , the bending rigidity changes during one cycle, and the peak width of the natural vibration of the dynamic vibration absorber 14 becomes wider (the Q value becomes larger), resulting in a so-called damping effect. Therefore, the peak width of the maximum damping frequency generated by achieving the natural vibration of the dynamic vibration absorber 14 and the natural vibration of the support system of the rotary compressor 1 is wide, and a vibration reduction effect can be obtained in a wide frequency band.

In addition, by inserting and fixing the protruding part 17a of the fixture 17 and the protruding part 15a of the inertial body 16 into both ends 16a of the connecting part 160, the ends 16a are fixed.

16a as well, the windings can be brought into close contact with each other, and the connecting portion 1
Since a stable bending rigidity of 6 is obtained, the natural frequency of the dynamic vibration absorber 14 can be stabilized.

Furthermore, by fixing the hook-shaped fixing parts 16b and 16d provided at both ends 16a and 16a of the coupling part 16 to the fixture 1a and the inertial body 16 with poles 19 and 18, the coupling part 16 and the fixture 17 are fixed. and the inertial body 16 can be firmly fixed.

Note that the same effect can be obtained by fixing the inertial body 16, the connecting portion 16, and the fixing member 17 to the compression element portion in the same manner as the cage of the sealed case 2.

Effects of the Invention As described above, the present invention provides a connecting portion made of a tension coil spring having arms extending from both ends of a winding in a direction substantially perpendicular to the winding central axis, and one end of the winding of this connecting portion. It has a cylindrical protrusion that is inserted and fixed into the winding, and the arm extending from one end of this winding is fixed, and the compression element or the compression element and the electric motor are fixedly attached to and fixed in a sealed case that is housed therein. A fixing device, and an inertial body having a cylindrical protrusion inserted and fixed to the other end of the winding of the connecting part, and further having an arm extending from the end of the winding fixed. This creates a dynamic vibration absorption structure that damps the vibrations that occur during operation of the rotary compressor, and the damping effect provides a vibration reduction effect over a wide frequency band. Not only can a sufficient vibration reduction effect be obtained even if there is a change in the rotational frequency, but also the dynamic vibration absorber can be prevented from being destroyed due to vibration or impact, and a more stable vibration reduction effect can be obtained.

[Brief explanation of drawings]

Fig. 1 is a side view of a vibration damping device for a rotary compressor showing an embodiment of the present invention, Fig. 2 is a side view of a connecting part of the vibration damping device, and Fig. 3 is a side view of the vibration damping device installed. FIG. 4 is a sectional view of a rotary compressor equipped with a conventional vibration damping device. 2... Sealed case, 14... Dynamic vibration absorber, 15... Inertial body, 16... Connection part,
17... Fixture. Name of agent: Patent attorney Shigetaka Awano and 1 other person

Claims (1)

[Scope of Claims] A connecting part made of a tension coil spring having arms extending from both ends of the winding in a direction substantially perpendicular to the winding central axis, and a cylinder inserted and fixed into one end of the winding of this connecting part. The arm part extending from one end of the winding of this connecting part is fixed by having a protruding part like this, and is attached and fixed to a closed case in which the compression element part or the compression element part and the electric motor part are fixedly housed. and an inertial body having a cylindrical protrusion inserted and fixed to the other end of the winding of the connecting part, and further having an arm extending from the end of the winding fixed. Vibration damping device for mold compressor.