JPH0315679A - 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, 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. 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 due to variation in rotational frequency, variation in manufacturing, etc., can be prevented, and fatigue due to vibration and the damage of the dynamic vibration reducer 14 due to shock can be also 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 technique 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 sealed 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 thereof, and its outer peripheral portion is welded and fixed within the sealed case 2. 1
0 is the discharge force, which is fixed to the upper bearing 9 by a presser. Reference numeral 11 designates a dynamic vibration absorber, which is composed of an inertial rest 12 and a shaft-shaped connecting portion 13 with this inertial body 12 provided at an end 13a, and the other end 13b of the connecting portion 13 is connected to the sealed case 2. 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 body 12, the length of the connecting portion 13, the diameter of the cross section, 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 configuration, the peak (Q value) of the natural vibration of the dynamic vibration absorber 11 is sharp, and this occurs due to the natural vibration of the support system of the rotary compressor 1 itself. The peak of the maximum attenuation frequency (Q value) 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. Due to changes in the natural vibration due to variations in the frequency, the maximum damping frequency caused by the connection with the support system of the rotary compressor 1 itself changes, and the frequency between the maximum damping frequency and the rotational frequency of the rotary compressor 1 changes. If the difference becomes large, the vibration damping effect will become 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 shaft; an inertial body having a substantially cylindrical shaft; 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. a tightening fixing part having a generally screw-shaped inner peripheral part installed so that the height is lower than the height of the fixture and the shaft of the inertial body; The structure is such that it is fixedly housed in a closed case or fixed to a non-rotating part of the electric compression element section. Operation The present invention uses the above-mentioned structure to absorb vibrations generated during operation of a rotary compressor by using a dynamic vibration absorber that is composed of a coil-shaped connecting portion fixed to the rotary compressor main body, an inertial body, and a fixture. By vibrating in the opposite phase to the vibration of the rotary compressor, it is damped by supplying a reaction torque to the rotary compressor, and by making the connecting part between the fixture and the inertial body into a coil shape. , because the damping effect is obtained, the vibration damping effect width is widened, and the vibration damping effect is prevented from deteriorating due to fluctuations in the rotational frequency of the rotary compressor, manufacturing variations, etc., and the end of the fixed connection part The stress caused by deformation caused by vibration and 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 variations in fixation, and the outer periphery of the connection part can be fixed with a tightening fixing part whose inner periphery is approximately threaded. This will also prevent it from falling off. 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, parts that are the same as those in the conventional example will be given the same reference numerals and the explanation will be omitted. Figures 1 to 4
The figure shows 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 inertia rest 15 and the fixture 17 each have a substantially cylindrical shaft 15.
a, 17a are provided, both ends of the connecting part 16 are press-fitted and fixed to the core keychain 15a+17a, and the outer peripheral part of the connecting part 16 has an inner peripheral part 1B& and 19a that are substantially screw-shaped, and the height is set to the core keychain 15a. , 17a are tightened and fixed so as to press against the inertia body 15 and fixture 17, respectively, and screws 18b and 1g are tightened to prevent the tightening fixing parts 18.19 from turning and loosening.
It is fixed to the inertial body 15 and the fixture 17 at b. or,
The dynamic vibration absorber 14 is the fixture 17f! : It is fixed to the rotary compressor 1 by welding and fixing it to the sealed case 2.

In addition, the dynamic vibration reducer 14 is configured such that the maximum damping frequency generated by achieving 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. , the shape of the connecting part 16, the weight and shape of the inertial body 15 and the tightening fixing part 18, etc. 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,
Sealed case 2 vibrates greatly. However, the inertia body 15 and the fastening fixing part 18 of the dynamic vibration absorber 14, which are 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, 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 closely coiled shape and the deformation is used as the bending direction, the connecting part 16 does not create a gap between the windings 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.
Since the bending rigidity changes during one cycle, it is nonlinear. Therefore, by obtaining the Dumbink 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 rapid formation 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. 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 manufacturing variations in 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
There is no possibility that the wire will break, making it extremely reliable.

Furthermore, the connecting portion 16 is press-fitted into the inertial body 15 and the axles 15a, 17a of the fixing device 17, and the outer circumference is firmly fixed with tightening fixtures 18, 19, so that it can be press-fitted into the axles 15a+17a. By making the fixing position clear, variations in the natural vibration of the dynamic vibration absorber 14 can be suppressed to a small level,
In addition, the tightening fixtures 18 and 19, which are lower than the height of the shinkeyaki 15a * 17a, can be securely fixed without affecting the length of the connecting part 16, thereby making the natural vibration of the dynamic vibration reducer 14 stable. This can prevent the inertial body 15 and fixture 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. A closed case is provided with a tightening fixing part whose inner circumferential part is substantially screw-shaped, and the fixing device is fixedly housed in an electric compression element part consisting of a compression element part and an electric motor part, or a rotating body of the electric compression element part. By using a vibration damping device for a rotary compressor that is fixed to non-contact parts, a dynamic vibration absorber structure is formed using an inertial body, a fastening part, a connecting part, and a fixture, and the vibration that occurs when the rotary compressor is operated can be reduced. By damping the vibration and making the connection part coil-shaped, a damping effect can be obtained, and a vibration damping effect can be obtained in a wide frequency band. Not only can a sufficient vibration damping effect be obtained even if there is a vibration, but it can also prevent fatigue caused by vibration and damage to the dynamic vibration absorber due to impact, so 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 same compressor, 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° connection part, 17・・
Fixing tool, 17a... Mandrel, 18.19... Tightening fixing part, 18a, 19a... Inner peripheral part.

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 tightening member having a substantially screw-shaped inner peripheral part installed on the outer peripheral part of both ends of the connecting part so that the height of the contact part is lower than the height of the axle of the fixing device and the inertial body. Vibration of a rotary compressor in which the fixing device is fixedly housed in an electric compression element section consisting of a compression element section and an electric motor section, or a part of the electric compression element section that is not a rotating body. damping device.