JPH0436076A - Vibration damping device for rotary compressor - Google Patents

Abstract

PURPOSE:To prevent lowering of the effect of vibration damping and breakage of a dynamic vibration absorber by providing a dynamic vibration absorber composed of a coupling part formed of a low pitch coil spring, an inertia body and a fixture. CONSTITUTION:vibration from a rotary compressor 1 is damped by a dynamic vibration absorber 14 which is composed of an inertia body 15, a coupling part 16 is formed of a low pitch coil spring and a fixture 17 and which applies a reaction torque. Since the coupling part 16 is formed of the low pitch coil spring, the natural vibration characteristic of the dynamic vibration damper 14 is nonlinear. Accordingly, a damping effect can be obtained so that the range of vibration damping effect becomes larger. Thus, it is possible to prevent lowering of the vibration damping effect which is caused by variations in the rotational frequency of the rotary compressor 1 and uneven quality of the dynamic vibration damper 14. Further, it is possible to reduce stress caused by deformation of the end part of the coupling part 16 fixed to a fixture, due to vibration and shocks, thereby it is possible to prevent breakage of the dynamic vibration damper 14.

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.

2. Description of the Related Art In recent years, compressors used in refrigeration equipment, etc. have been shifting from reciprocating types to rotary types from the standpoint of energy and space saving. These rotary compressors usually have an electric compression element consisting of a compression element section and an electric motor section directly fixed and housed in a sealed case. The rotational vibrations and the like generated around the centrifuge directly vibrate the closed case, and the vibrations sometimes vibrate the main body of the refrigerant piping, freezing and refrigeration equipment, etc., and generate large noise.

Therefore, as a conventional technique for damping the vibrations of a rotary compressor, for example, as shown in Japanese Patent Publication No. 58-5486, a rotary hermetic electric compressor using a beam vibration absorber is proposed. It has a vibration damping structure.

Hereinafter, an example of the vibration damping structure of the conventional rotary compressor mentioned above will be explained with reference to the drawings.

FIG. 6 is a partial sectional view of a conventional rotary compressor. In FIG. 0, 1 is a rotary compressor, and 2 is a closed case. 8
3a is a stator of the electric motor, which is fixed in the sealed case 2 by shrink fitting. 3b is the mouth of the electric motor, which is connected and fixed to the crankshaft 5 of the compression unit 5I4 by shrink fitting. A piston 6 is rotatably mounted on the eccentric portion of the crankshaft 5. A cylinder 7 has a lower bearing 8 and an upper bearing 9 disposed at both ends thereof, and its outer peripheral portion is welded and fixed within the sealed case 2.

Reference numeral 10 denotes a discharge cover, which is fixed to the upper bearing 9 at the engineering university. 11 is a dynamic vibration absorber, which includes an inertial body 12 and this inertial body 12
and a shaft-shaped connecting part 13 provided at the end part 13a, and perpendicular to the outer wall surface of the sealed case 2,
The other end 13b of the connecting portion 13 is fixed by resistance welding.

In addition, the inertial body 12 is adjusted so that the first-order natural frequency of the dynamic vibration absorber 11 almost matches the rotational frequency of the rotary compressor.
The weight and shape of the connecting portion 13, the length of the connecting portion 13, the diameter of the cross section, etc. 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 the cylinder 7, the pressure inside the cylinder 7 fluctuates greatly during one rotation of the crankshaft 5, causing fluctuations in the angular velocity of the rotation of the crankshaft 5, and as a reaction, the pressure inside the cylinder 7 changes greatly. Receive power. Therefore, vibration occurs in the direction of rotation about the axial center of the crankshaft 5, and the sealed case 2 vibrates greatly. However, as the inertial body 12 of the dynamic vibration absorber 11, which is arranged in the sealed case 2 and whose natural frequency is adjusted to almost match the rotational frequency of the rotary compressor 1, vibrates, the dynamic vibration absorber 11 becomes airtight. At the installation location in the case 2, the reaction torque is transferred to the sealed case 2 via the connection part 13 of the dynamic vibration absorber 11.
The vibration of the rotary compressor 1 is damped by supplying the rotary compressor 1 to the rotary compressor 1 and canceling the vibration torque of the rotary compressor 1.

Problems to be Solved by the Invention However, in the above configuration, the peak of the natural vibration of the dynamic vibration absorber 11 is sharp, so a large reaction torque is generated at the peak of the natural vibration, but when it deviates from the peak, the reaction torque becomes extremely large. Therefore, due to changes in the rotational frequency due to changes in the operating conditions of the rotary compressor 1 and changes in natural vibration due to variations in the manufacturing process of the dynamic vibration absorber 11, the rotational frequency of the rotary compressor 1 and When the frequency difference from the natural frequency of the dynamic vibration absorber 11 becomes large, the vibration damping effect becomes insufficient.

Furthermore, stress is concentrated on the end portion 13b of the connecting portion 18 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, the vibration damping device for a rotary compressor of the present invention has hooks from both ends of the windings on a plane substantially perpendicular to the central axis of the windings. a connecting portion made of a close coil spring; an inertial body having a substantially helical shape portion and fixed with a hook such that the connecting portion is in close contact with the end surface of the winding portion of the connecting portion; has a spiral shaped part,
and a dynamic vibration absorber in which the connecting part is configured of a fixing member fixed to the substantially spiral-shaped part with a hook so as to be in close contact with the end surface of the other winding part of the connecting part, and the dynamic vibration absorber is The fixing device is attached and fixed to a non-rotating part of the electric compression element consisting of a compression element part and an electric motor part, or to a closed case in which the electric compression element is fixedly housed.

Effect of the present invention With the above-described configuration, a dynamic vibration absorber composed of a connecting portion fixed to the rotary compressor main body, an inertial body, and a fixture can absorb vibrations generated during operation of the rotary compressor. By supplying a reaction torque to the vibration of the machine and attenuating it, and by using a tightly coiled spring as the connection part, the natural vibration characteristics of the dynamic vibration absorber become non-linear, so a damping effect is obtained and the vibration is reduced. The damping effect width is widened, and it prevents the vibration damping effect from decreasing due to fluctuations in the rotational frequency of the rotary compressor or variations in the manufacturing process of the dynamic vibration absorber. Stress caused by deformation caused by vibration or impact can be reduced. Furthermore, the connecting portion has a hook on a plane substantially perpendicular to the winding central axis, and the end surface of the winding portion of the connecting portion is in close contact with the generally spiral-shaped portion of the inertial body and the fixture. Since it is fixed, the natural vibration of the dynamic vibration absorber can be made stable by being able to securely fix it.

Embodiment Hereinafter, an embodiment of the vibration damping device for a rotary compressor according to the present invention will be described with reference to the drawings.

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 5 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 includes an inertial body 15, a connecting part 16 consisting of a tight coil spring with initial tension, and a fixture 1.
It consists of 7. Hooks 16b and 16C are provided from the ends of the connecting portion 16 on a plane perpendicular to the winding center axis 15a. The inertial body 15 has a generally spiral-shaped portion 15a in which the end surface 16d of the winding portion of the connecting portion 16 is in close contact with the generally spiral-shaped portion 15a. The hook 16b is tightened and fixed by the bolt 18 so that the hook 16b is tightly attached with a force greater than the initial tension of the hook 16b. The fixing device 17 has a winding end surface 16e of the connecting portion 16.
The connecting portion 16 has a generally spiral-shaped portion 17a in a shape in which the winding portion end face 16e is in close contact with the generally spiral-shaped portion 17a.
The hook 16c is tightened and fixed with a bolt 19 so as to be in close contact with the hook 16c with a force higher than the initial tension. Furthermore, the dynamic vibration reducer 14 is fixed to the rotary compressor 1 by welding and fixing the fixture 17 to the closed case 2.

In addition, the dynamic vibration reducer 14 is configured to adjust the shape and initial tension of the connecting portion 16, the weight and shape of the inertial body 15, and the shape and initial tension of the inertial body 15 so that the first-order natural frequency almost matches the rotational frequency of the rotary compressor 1. , the fixing position to the fixture 17, etc. 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 the cylinder 7, the pressure inside the cylinder 7 fluctuates greatly during one rotation of the crankshaft 5, causing fluctuations in the angular velocity of the rotation of the crankshaft 5, and as a reaction, the pressure inside the cylinder 7 changes greatly. Receive power. Therefore, vibrations occur in the rotational direction around the axis of the crankshaft 5, and the sealed case 2 vibrates greatly. However, as the inertial body 15 of the dynamic vibration absorber 14, which is arranged in the sealed case 2 with its natural frequency adjusted to almost match the rotational frequency of the rotary compressor 1, vibrates, the dynamic vibration absorber 14 becomes airtight. At the installation location in the case 2, a reaction torque is supplied to the closed case 2 via the connecting part 16 and the fixture 17 of the dynamic vibration absorber 14, and vibrations are damped by canceling the vibration torque of the rotary compressor 1. .

At this time, since the connecting portion 16 is a tight coil spring having initial tension and the deformation is used as the bending direction, the connecting portion 1
6 has high bending rigidity because no gap is created between the windings when the amount of deformation in the bending direction is small in one cycle of vibration, but when the amount of deformation in the bending direction becomes large, a gap is created between the windings and the bending rigidity is small. Therefore, since the bending rigidity changes during one cycle, it becomes non-linear. Therefore, the peak width of the natural vibration of the dynamic vibration reducer 14 becomes wider by obtaining a damping effect. As a result, the width of the vibration damping effect 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 becomes wider, and the vibration damping effect is obtained in a wide frequency band. mold compressor 1
A sufficient vibration damping effect can be obtained even if there is a change in the rotational frequency due to a change in the operating conditions of the dynamic vibration absorber 14 or a change in the natural vibration due to variations in the manufacturing process of the dynamic vibration absorber 14.

Furthermore, by using a tightly coiled spring for the connecting portion 16, the stress added to the connecting portion 16 for the same displacement of the inertial body 15 is smaller than that for beams made of the same material and having the same linear shape, and the stress applied to the connecting portion 16 due to fatigue due to vibration and impact is smaller. Even if there is a large deformation, the connecting portion 16 will not break, making it extremely reliable.

Moreover, the connecting part 16 has hooks 16b and 1ace on a plane perpendicular to the winding central axis 16a, and the winding part end surface 1
The hooks 16bp16c are attached to the bolts 18.1 so that the hooks 16d and 16e are brought into close contact with the inertia body 15 and the substantially spiral-shaped portion 15at17a of the fixture 17 with a force greater than the initial tension of the connecting portion 16.
9, the winding end faces lad, l
It is possible to suppress variations in the natural vibration caused by a large change in the bending rigidity of the connecting portion 16 due to the presence or absence of contact between the ee and the contact strength being weaker than the initial tension. Furthermore, by providing the hooks 16b and 16c on a plane perpendicular to the winding central axis 16a, the height of the entire dynamic vibration absorber 14 can be made lower than when the hooks are provided on a plane passing through the central axis 16a. Therefore, the dynamic vibration absorber 14 can be made compact.

Effects of the Invention As described above, the present invention has a connecting portion made of a close coil spring having hooks from both ends of the winding on a plane substantially perpendicular to the central axis of the winding, and a substantially spiral-shaped portion, and the connecting portion has an inertial body fixed to the substantially spiral-shaped portion by a hook so that the end surface of the winding portion of the connecting portion is in close contact with the generally spiral-shaped portion, and the connecting portion has the generally spiral-shaped portion. A dynamic vibration absorber is provided with a fixing device fixed with a hook to the end surface of the other winding portion of the connecting portion, and the fixing device of the dynamic vibration absorber is attached to the compression element portion and the electric motor portion. By making it a vibration damping device for a rotary compressor, which is a non-rotating part of an electric compression element made of
A dynamic vibration absorber consisting of a connecting part and a fixture damps the vibrations that occur during operation of a rotary compressor, and by using a tight coil spring for the connecting part, the vibration characteristics of the dynamic vibration absorber become non-linear. Since a damping effect can be obtained, vibration damping effect can be obtained in a wide frequency band.
It is extremely effective because it not only provides a sufficient vibration damping effect even when the rotational frequency changes due to changes in the operating conditions of the rotary compressor, but also prevents fatigue caused by vibration and damage to the dynamic vibration absorber due to shock. A stable vibration damping effect can be obtained. The connecting portion has a hook on a plane substantially perpendicular to the central axis of the winding, and the end surface of the winding portion of the connecting portion is in close contact with the generally spiral-shaped portion of the inertial body and the fixture. Since it is fixed, it is possible to stabilize the natural vibration of the dynamic vibration absorber by securely fixing it, and to have a compact dynamic vibration absorber structure.

[Brief explanation of drawings]

Fig. 1 is a sectional view of a rotary compressor showing an embodiment of the present invention, Fig. 2 is a top view of a connecting part of a damping device used in the compressor, and Fig. 3 is a diagram of a damping device used in the compressor. 4 is a perspective view of the inertial body of the damping device used in the same compressor, FIG. 5 is a perspective view of the fixture of the damping device used in the same compressor, and FIG. 6 is a conventional rotary type. It is a sectional view of a compressor. 2... Sealed case, 14... Dynamic vibration absorber, 15...
Inertial body, 15a...Substantially spiral shaped part, 16...Connection part, 18a...Winding center axis, 16b, 16c... = Hook, lad, 1 (3e,. Winding part end surface, 17...・Fixing tool, 17a...approximately spiral shaped part. Name of agent: Patent attorney Shigetaka Awano (1 person) Figure 16 Figure 16

Claims (1)

[Claims] a connecting portion made of a close coil spring having hooks on a plane substantially perpendicular to the winding center axis from both ends of the winding; and a generally spiral-shaped portion, and the connecting portion is connected to the approximately spiral-shaped portion. an inertial body fixed by a hook so as to tightly contact the end surface of the winding part of the connecting part, and a substantially spiral-shaped part, and the connecting part is attached to the other winding part of the connecting part. A dynamic vibration absorber is provided with a fixing device that is fixed with a hook so that the end faces are in close contact with each other, and the fixing device of the dynamic vibration absorber is a component that is not a rotating body of an electric compression element consisting of a compression element part and an electric motor part. Or, a vibration damping device for a rotary compressor, which is fixedly attached to a closed case in which the electric compression element is fixedly housed.