JPH04179895A - Vibration damping equipment for rotary compressor - Google Patents

Abstract

PURPOSE:To prevent the lowering of vibration damping effect by using a tight lock type coil spring as a connecting part in a dynamic vibration reducer constituted of a connecting part fixed to a rotary compressor body, an inertial body and a fixture. CONSTITUTION:A dynamic vibration reducer 14 is constituted of an inertial body 15, a connecting part 16 consisting of a tight lock type coil spring having initial tension and a fixture 17, and shafts 15a and 17a, which have a cross sectional form of an approximately triangular shape and are in an approximately pillar form, are arranged respectively in the inertial body 15 and the fixture 17, and both edge parts of the connecting part 16 are fixed to the shafts 15a and 17a by means of press fitting, and hooks 16a and 16b of the connecting part 16 are also fixed firmly to the inertial body 15 and the fixture 17 respectively by means of screws 18 and 19. The dynamic vibration reducer 14 is fixed to a rotary compressor 1 by fixing the fixture 17 to a closed case 2 by means of welding. By using the tight lock coil spring as the connecting part, vibration damping effect can be obtained in a wide frequency domain so that even if there are changes in rotational frequencies accompanied by changes in operational conditions of the rotary compressor, sufficient vibration damping effect can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a vibration damping device for a rotary compressor used in a freezing and refrigeration system or 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 generated around the axis directly vibrate the sealed case, and the vibrations vibrate the main body of the refrigerant piping, freezing and refrigerating equipment, etc., sometimes generating 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. 5 is a partial sectional view of a conventional rotary compressor. In the figure, 1 is a rotary compressor, and 2 is a closed case. 3
is an electric motor, and 3a is a stator of the electric motor, which is fixed in the sealed case 2 with a shrink fit. 8b is a rotor of an electric motor, which is connected and fixed to the crankshaft 5 of the compression element 4 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. 1
0 is a discharge cover, which is press-fitted and fixed to the upper bearing 9. Reference numeral 11 denotes a dynamic vibration absorber, which is composed of an inertial body 12 and a shaft-shaped connecting portion 13 with the inertial body 12 provided at an end 13a. It is fixed by resistance welding so that it is perpendicular to the outer wall surface. The first-order natural frequency of the dynamic vibration absorber 11 is determined by adjusting the weight and shape of the inertial body 12, the length of the connecting portion 13, the diameter of the cross section, etc. so that it almost matches the rotational frequency of the rotary compressor. I'm making adjustments.

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 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 increases. It will drop drastically. Therefore, due to changes in the rotation 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 rotation frequency of the rotary compressor 1 and the dynamic vibration absorber 11 If the frequency difference from the natural frequency is large, the vibration damping effect will be insufficient.

Further, the end portion 13b of the connecting portion 13 is subject to stress caused by 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 consists of a tight coil spring having hooks at both ends on a plane substantially perpendicular to the central axis. A connecting part,
a fixture for fixing the hook of the connecting part; It has a substantially columnar mandrel with a cross-sectional shape having three or more vertices into which the other end is inserted and fixed, and an inertia body which fixes the other hook of the connecting part, and the fixing tool is connected to the compression element part. and a closed case in which an electric compression element section consisting of an electric motor section is fixedly housed, or fixed to a part of the electric compression element section that is not a rotating body.

Effect of the present invention With the above-described configuration, the dynamic vibration absorber composed of the connecting portion fixed to the rotary compressor main body, the inertial body, and the fixture can absorb vibrations generated during operation of the rotary compressor. By supplying a reaction torque to the vibration of the dynamic vibration reducer, and by using a tightly coiled spring as the connection part, the natural vibration characteristics of the dynamic vibration absorber become non-linear. The 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, and also prevents vibrations and shocks at the ends of the fixed joints. Stress due to the resulting deformation can be reduced. Furthermore, by inserting and fixing the connecting part into the substantially columnar mandrel having a cross-sectional shape having three or more vertices of the fixture and the inertial body,
The apex of the mandrel makes the separation position between the connecting part and the mandrel clear, which makes it possible to fix the connecting part and reduce variations in the effective number of turns.It also reduces variations in the natural vibration of the dynamic vibration reducer during manufacturing, resulting in stable vibration. A damping effect can be obtained. Moreover, by providing hooks at both ends of the connecting part,
It is possible to firmly fix the installation without affecting the effective number of turns of the connecting part by screwing it to the fixture or inertial body, and it also reduces the variation when fixing, so it is possible to reduce the natural vibration of the dynamic vibration absorber. This makes it possible to maintain stability while preventing loss of vibration damping effect due to falling off of the inertial body, etc.

EXAMPLE Hereinafter, a first example of a 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 4 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, an inertia body, a connecting part 16 made of a tight coil spring having an initial tension of 15°, and a fixture 1.
It consists of 7. The inertial body 15 and the fixture 17 each have a substantially columnar shaft 1 having a substantially triangular cross-sectional shape.
5 av 17a are provided, both ends of the connecting portion 16 are press-fitted and fixed to the mandrel 15a*17a, and the hooks 16a and 16b of the connecting portion 16 are respectively screwed into screws 18.1.
Inertial body 15 at 9. It is firmly fixed to a fixture 17.

Furthermore, the dynamic vibration absorber 14 connects the fixture 17 to the sealed case 2.
It is fixed to the rotary compressor 1 by welding and fixing it to the rotary compressor 1.

In addition, the dynamic vibration absorber 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 inertial body 15 so that the first-order natural frequency almost matches the rotational frequency of the rotary compressor 1. The fixing position of the connecting portion 16 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 fluctuates greatly. receive power from etc. This causes vibrations in the rotational direction around the axis of the crankshaft 5, causing the sealed case 2 to vibrate 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 via the fixture 17 of the dynamic vibrator 14 to cancel the vibration torque of the rotary compressor 1, thereby damping the vibration.

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 a large bending rigidity because there is no gap 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 decreases. Since the bending rigidity becomes smaller, the bending rigidity changes during one cycle, resulting in non-linearity. 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 caused by the coupling of 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 can be obtained in a wide frequency band. 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 rotary compressor 1 or a change in the natural vibration due to variations in the manufacturing process of the dynamic vibration absorber 14.

Furthermore, by making the connecting portion 16 a close coil spring, the stress added to the connecting portion 16 for the same displacement of the inertial body 15 is small compared to a beam made of the same material and the same wire diameter, and the stress applied to the connecting portion 16 due to fatigue due to vibration or impact is smaller. Even if there is a large deformation, the connecting portion 16 will not break, making it extremely reliable.

Furthermore, the connecting portion 16 is a substantially columnar shaft 15a in which the inertial body 15 and the fixture 17 have a substantially triangular cross-sectional shape.

By press-fitting and fixing it to 17a, the core is $15a.

Since the cross-sectional shape of the dynamic vibration absorber 17a is approximately triangular, the separation position of the connecting portion and the mandrel can be clearly determined by the triangular apex, and it is possible to fix the connecting portion and reduce variations in the effective number of turns. Since the variation in natural vibration can be suppressed to a small level, a stable vibration damping effect can be obtained.

Also, connect the hooks 16a and 16b of the connecting portion 16 to the inertial body 15. with screws 18 and 19, respectively. Since it is firmly fixed to the fixture 17, it can be fixed very easily and reliably without affecting the effective number of turns of the connecting part 16, and the inertial body 15 and Fixture 1
7 can be prevented from falling off from the connecting portion 16 and losing the vibration damping effect.

Effects of the Invention As described above, the present invention includes a connecting portion made of a close coil spring having hooks at both ends on a plane substantially perpendicular to the central axis, and one end of the winding of the connecting portion is inserted and fixed. 3
It has a substantially columnar mandrel with a cross-sectional shape having three or more vertices, a fixture for fixing the hook of the connecting part, and three or more vertices for inserting and fixing the other end of the winding of the connecting part. and an inertial body for fixing the other hook of the connecting part, the closed case fixedly housing the electric compression element part consisting of the compression element part and the electric motor part in the fixing device. Alternatively, by using a vibration damping device for a rotary compressor that is fixed to a part of the electric compression element section that is not a rotating body, a dynamic vibration absorber structure is formed by the inertial body, the connecting portion, and the fixture, and the vibration damping device for the rotary compressor is fixed. By attenuating the vibrations that occur during operation, and by using a close coil spring for the connection part, a damping effect can be obtained, so the vibration damping effect can be obtained in a wide frequency band, so it can be used to reduce the change in operating conditions of the rotary compressor. It is possible to obtain a sufficient vibration damping effect even when there is a change in the rotational frequency due to the vibration, and it also prevents damage to the dynamic vibration absorber due to fatigue caused by vibration or shock, resulting in an extremely stable vibration damping effect. It is. In addition, by externally fixing the connecting portion to a substantially columnar mandrel with a cross-sectional shape having three or more vertices, the separation position of the connecting portion and the mandrel is made clear by the apex of the mandrel, which improves the fixation and effectiveness of the connecting portion. It is possible to suppress variations in the number of turns to a small value and stabilize the natural vibration of the dynamic vibration reducer. Furthermore, since the connecting part is fixed to an inertial body or a sealed case using a hook on a plane that is approximately perpendicular to the central axis of the connecting part, it can be firmly fixed without affecting the effective number of turns of the connecting part. Therefore, it is possible to stabilize the natural vibration of the dynamic vibration reducer while preventing the vibration damping effect from being lost due to falling off of the inertial body, etc.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a vibration damping device for a rotary compressor showing an embodiment of the present invention, FIG. FIG. 4 is a sectional view of a rotary compressor showing an embodiment of the present invention, and FIG. 5 is a sectional view of a conventional rotary compressor. 2... Sealed case, 14... Dynamic vibration absorber, 15...
Inertial body, 15a... Mandrel, 16... Connecting part, lea
, 16b... hook, 17... fixture, 17a...
・Mandrel, 18.19...Screw. Agent's name Patent attorney Akira Koeji Osamu 2 idiots 2-11 seats M case 14-dynamic suction bed spring 15--Ikki Ojo 15 (L---/Ji Sweep 16--Series Connection part 16α, 16b -Hook lγ-11 times 吏 tool 17α-=-Shin Zen 11 figure lθ, t9-screw figure 2 16 series connection part 16α, teb-hook 1G, 17-same complete tool No. 31y4.Q, a- 10 dedication 2-
Soluble layer case 14--Ikkunsu's costume 15-11 name body 16-Connection part 16a, 16b--Hook 17--Hook 17--Drinking fixture lθ, t9-Nego 114 figure wE5 figure

Claims (1)

[Claims] A connecting part consisting of a close coil spring having hooks on a plane substantially perpendicular to the central axis at both ends, and a cross-sectional shape having three or more vertices into which one end of the winding of the connecting part is inserted and fixed. It has a columnar mandrel, a fixture for fixing the hook of the connecting part, and a substantially columnar mandrel with a cross-sectional shape having three or more vertices into which the other end of the winding of the connecting part is inserted and fixed. , an inertial body that fixes the other hook of the connecting part, and the fixing device is a closed case that fixedly houses an electric compression element section consisting of a compression element section and an electric motor section, or a rotating part of the electric compression element section. A vibration damping device for a rotary compressor that is fixed to a non-body part.