JPH0315680A - Vibration damping device of rotary compressor - Google Patents

Abstract

PURPOSE:To keep vibration damping effect stably for a long period of time by connecting an inertia body for vibration damping to a fixture through a coiled connector with C-shaped connecting parts, and fixing the fixture to the closed case or non-rotating part of a rotary compressor. CONSTITUTION:A rotary compressor 1 is so constructed that an electric motor 3, compression element 4, piston 6, cylinder 7, etc., are housed in a closed case 2. In this case, a dynamic vibration reducer 14 for damping the vibration of the rotary compressor 1 is so constructed that an inertia body 15 and a fixture 17 are connected to each other through a coiled connector 16 with multiple tightening fixing parts 18 and 19. Also, the tightening fixing parts 18 and 19 made in C-shape member tighten the outer periphery of the connector 16 to fix the connector 16 to respective core bars 17a of the inertia body 15 and the fixture 17. The fixture 17 is fixed to a non-rotating part among the closed case 2 or electric compressor element 3 or 4. By this, the lowering of vibration damping effect can be prevented and fatigue, etc., due to vibration can also be prevented.

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 a refrigeration system or the like. Conventional technology In recent years, the compressors used in refrigerators and refrigeration systems have shifted from reciprocating types to rotary types in order to save energy and space. 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 shaft center directly vibrated the sealed case, and the vibrations caused the main body of the refrigerant piping, freezing and refrigeration equipment, etc. to vibrate, resulting in large noise. Therefore, as a conventional technology for damping the vibrations of a rotary compressor, for example, as shown in Japanese Patent Publication No. 58-5486,
There is a vibration damping structure for a rotary hermetic electric compressor that uses a beam type dynamic vibration absorber. An example of the vibration damping structure of the conventional rotary compressor mentioned above will be described below with reference to the drawings. Figure 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, 3a is a stator of the electric motor, which is fixed in a shrink fit inside the sealed case 2, and 3b is a rotor of the electric motor, which is connected and fixed with a crankshaft 5 of a compression element 4 by a shrink fit. There is. 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, and its outer circumference is welded and fixed within the sealed case 2. 1
0 is a discharge force par, which is press-fitted into the upper bearing 9 and fixed. 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. Furthermore, the dynamic vibration absorber 11 is generated by achieving the natural vibration of the support system of the rotary compressor 1 itself due to supporting and fixing the rotary compressor 1 and the first-order natural vibration of the dynamic vibration absorber 11. The weight and shape of the inertial rest 12, the length of the connecting portion 13, the cross-sectional diameter, etc. are adjusted so that the maximum damping frequency almost matches the rotational frequency of the rotary compressor 1. The operation of the vibration damping device for a rotary compressor constructed as described above will be explained 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,
The inertial body 12 of the dynamic vibration absorber 11, which is arranged in the sealed case 2 and whose natural frequency is adjusted so that the maximum damping frequency almost matches the rotational frequency of the rotary compressor 1, 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 through the connecting portion 13 of the dynamic vibration absorber 11 at the location where it is installed in the closed case 2, thereby damping the vibration. Problems to be Solved by the Invention However, in the above structure, since the peak (Q value) of the natural vibration of the dynamic vibration absorber 11 is sharp, the peak of the natural vibration of the rotary compressor 1 itself is combined with the natural vibration of the support system of the rotary compressor 1 itself. The peak of the maximum attenuation frequency (Q value) that occurs also becomes sharper. Therefore, when the maximum damping frequency and the rotational frequency of the rotary compressor 1 match, the damping effect is extremely large. The frequency difference between the maximum damping frequency and the rotational frequency of the rotary compressor 1 changes due to changes in the natural vibration due to variations in the maximum damping frequency caused by the rapid formation of the rotary compressor 1 itself with the support system. If it becomes too thick, 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, and may be subject to fatigue due to vibration or breakage due to 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 includes: a fixture having a substantially cylindrical mandrel; an inertial body having a substantially cylindrical mandrel; A coil-shaped connecting part whose one end is externally fixed to the axle of the fixture and the other end is externally fixed to the axle of the inertial body, and a height of a contact part on the outer periphery of both ends of the connecting part. is installed so that the height is lower than the height of the fixing device and the mandrel of the inertial body, and a tightening fixing part is configured such that the outer periphery of the connecting part is sandwiched between substantially C-shaped members and the connecting part is pressed against the mandrel. , the fixing device is fixed to a closed case in which an electric compression element section consisting of a compression element section and an electric motor section is fixedly housed, or to a part of the electric compression element section that is not a rotating body.

Effect The present invention has the above-described configuration, so that a dynamic vibration absorber composed of a coil-shaped connecting portion fixed to the rotary compressor main body, an inertial body, and a fixture can absorb the vibrations generated during operation of the rotary compressor. Damping is achieved by supplying a reaction torque to the rotary compressor by vibrating in the opposite phase to the vibration of the mold compressor, and by making the connecting part between the fixture and the inertial body into a coil shape. As a result, the vibration damping effect range is widened, and it prevents the vibration damping effect from decreasing due to fluctuations in the rotational frequency of the rotary compressor, manufacturing variations, etc. Stress caused by deformation caused by vibration or impact can be reduced.

Furthermore, the connection part can be fixed by externally fixing it to the fixture and the axle of the inertial body to reduce the variation in fixation, and by tightening the outer periphery of the connection part between the fixing parts and pressing it against the mandrel, it can be fixed to prevent it from falling off. It can also prevent EXAMPLE Hereinafter, an example of the vibration damping device for a rotary compressor of the present invention will be described with reference to the drawings. In order to avoid duplication of explanation, parts that are the same as those in the conventional example will be given the same reference numerals and the explanation will be omitted. 1 to 4 show an embodiment of the 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 15, a closely coiled connecting part 16, a fixing member 17, and tightening fixing parts 18 and 19. The inertial body 15 and the fixture 17 each have a substantially cylindrical shaft 1 5 al 1
A substantially C-shaped tightening member 18a of the fixing part 18.19 is provided, which fixes both ends of the connecting part 16 to the cores 15a and 17a under pressure, and tightens the outer peripheral part of the connecting part 16. , 18b and 19a, 19b respectively with screws 1
By tightening and sandwiching the connecting portions 8C and 19c, the connecting portion 16 is pressed against the mandrels 15a and 17a, respectively, and is firmly fixed. Further, the tightening member 18a. The height of the contact portion of 18b, 19a, 19b with the connecting portion 16 is the height of the mandrel 1.
The height is set to be lower than the height of 5a+17a. Further, the dynamic vibration absorber 14 is fixed to the rotary compressor 1 by welding the fixture 17 to the sealed case 2. Furthermore, the dynamic vibration reducer 14 is configured such that the maximum damping frequency caused by the connection between the natural vibration of the support system of the rotary compressor 1 and the natural vibration of the dynamic vibration absorber 14 almost matches the rotational frequency of the rotary compressor 1. In addition, the shape of the connecting part 16, the weight and shape of the inertia rest 15 and the tightening fixing part 18 are adjusted. The operation of the vibration damping device for a rotary compressor constructed as described above will be explained 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 in the rotational direction centering on the axis of the crankshaft 5 are generated,
The sealed case 2 vibrates greatly. However, the inertia body 15 and the fastening fixing part 18 of the dynamic vibration absorber 14, which is arranged in the sealed case 2 and whose natural frequency is adjusted so that the rotational frequency of the rotary compressor 1 and the maximum damping frequency almost match, are not tightly sealed. By vibrating in the opposite phase to the vibration of the case 2, the dynamic vibration absorber 14 supplies a reaction torque to the sealed case via the connecting portion 16 and the fixture 17 of the dynamic vibration absorber 14 at the location where it is installed in the sealed case 2. , damps vibrations. At this time, since the connecting part 16 is made into a tightly coiled shape and the deformation is used as the bending direction, the connecting part 16 does not create a gap between the cotton rolls as long as the amount of deformation in the bending direction is small in one cycle of vibration. Although the bending rigidity is high, when the amount of deformation in the bending direction increases, gaps are created between the windings and the bending rigidity decreases.
It is nonlinear because the bending stiffness changes during one cycle. Therefore, by obtaining a damping effect, the peak width of the natural vibration of the dynamic vibration reducer 14 becomes wider (the Q value becomes larger). As a result, the peak width of the maximum damping frequency caused by the combination 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 a vibration damping effect can be obtained in a wide frequency band. Therefore, 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 forming the connecting portion 16 in a coil shape, 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 added to the connecting portion 16 due to fatigue due to vibration or impact is smaller. Even if there is a large deformation of the connecting part 16
It does not break, making it extremely reliable. Furthermore, the connecting portion 16 is pressed onto the inertia body 15 and the axles 15a+17a of the fixing device 17, and its outer circumference is firmly fixed with tightening fixtures 18 and 19, so that it can be press-fitted into the axles 15a and 17a. By making the fixing position clear, the variation in the natural vibration of the dynamic vibration absorber 14 can be suppressed to a small level.
Furthermore, the mandrel 15a. The tightening fixtures 18 and 19, which are lower than the height of 17a, can be reliably fixed without affecting the length of the connecting part 16, thereby stabilizing the natural vibration of the dynamic vibration absorber 14 while also fixing the inertial body 15 and fixing. This can prevent the tool 17 from falling off from the connecting part 16 and losing the vibration damping effect. Incidentally, the same effect can be obtained by similarly fixing the dynamic vibration absorber 14 to the compression element section instead of the closed case 2. Effects of the Invention As described above, the present invention includes a fixture having a substantially cylindrical mandrel, an inertial body having a substantially cylindrical mandrel, one end of which is externally fixed to the mandrel of the fixture, and the other end of which is externally fixed to the mandrel of the fixture. a coil-shaped connecting part for externally fixing the part to the axle of the inertial body, and a contact part on the outer periphery of both ends of the connecting part such that the height of the contact part is lower than the height of the fixing device and the axle of the inertial body. and a tightening fixing part which is installed and has a substantially C-shaped member sandwiching the outer periphery of the coupling part to press the coupling part against the mandrel, and the fixing device is an electric compression element consisting of a compression element part and an electric motor part. By using a vibration damping device for a rotary compressor that is fixed to a sealed case in which the part is fixedly housed, or to a part of the electric compression element part that is not a rotating body, the inertial body, the clamping fixed part,
A dynamic vibration absorber structure is formed by the connecting part and fixture, which damps the vibrations that occur during operation of the rotary compressor.The connecting part is coiled, which provides a damping effect, so it can be used in a wide frequency band. Since a vibration damping effect can be obtained in the rotary compressor, sufficient vibration damping effect can be obtained even if the rotation frequency changes due to changes in the operating conditions of the rotary compressor. Since destruction can also be prevented, an extremely stable vibration damping effect can be obtained.

In addition, by externally fixing the connecting part to the mandrel, the variation in the fixing of the connecting part is suppressed to a minimum, thereby making the natural vibration of the dynamic vibration absorber stable. Furthermore, the fixed part is tightened at a lower height than the mandrel, making it stronger. By fixing it, it is possible to securely fix it without affecting the length of the connecting part, thereby making the natural vibration of the dynamic vibration absorber stable, and preventing the vibration damping effect from being lost due to falling off of the inertial body, etc. This is something that can be done.

[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 sectional view of a damping device used in the compressor, and Fig. 3 is a tightening and fixing part of the damping device used in the compressor. 4 is a perspective view of a fixture of a damping device used in the compressor, and FIG. 5 is a sectional view of a conventional rotary compressor.

Claims (1)

[Claims] a fixture having a substantially cylindrical mandrel; an inertial body having a substantially cylindrical mandrel; one end externally fixed to the mandrel of the fixture, and the other end externally fixed to the mandrel of the inertial body; A coil-shaped connecting part and a substantially C-shaped member are installed on the outer periphery of both ends of the connecting part so that the height of the contact part is lower than the height of the fixing device and the axle of the inertial body. and a tightening fixing part that sandwiches the outer periphery of the coupling part and presses the coupling part against the mandrel, and the fixing tool is installed in a sealed case that fixedly houses an electric compression element part consisting of a compression element part and an electric motor part, or A vibration damping device for a rotary compressor that is fixed to a non-rotating part of the compression element.