Hermetic electric compressor and refrigeration unit including non-resonating support structure for the compressor
View Patent ↗A hermetic electric compressor including sealed container and coil spring provided for elastically supporting electric compression element housed in sealed container. A consideration has been made to avoid the coincidence in the resonance frequency between coil spring mounted with electric compression element and mechanical vibration caused by electric compression element, or a cavity formed in space. By so doing, creation of a resonation with coil spring is suppressed, and noises and vibrations with the hermetic electric compressors are reduced.
1. A hermetic electric compressor comprising
a sealed container, and
a plurality of coil spring for elastically supporting an electric compression element housed within the sealed container from bottom of the sealed container; wherein
the coil spring mounted with the electric compression element has an uneven pitch so that self-resonance frequency of the coil spring does not coincide with resonance frequency of mechanical vibration caused by operation of the electric compression element.
2. The hermetic electric compressor of claim 1 , wherein resonance frequency of the coil spring does not coincide with a cavity resonance frequency formed in a cavity within the sealed container.
3. The hermetic electric compressor of claim 2 , wherein
the peak of resonance frequency of the coil spring and the cavity resonance frequency are separated from each other for at least 100 Hz.
4. The hermetic electric compressor of claim 2 , wherein
resonance frequency of the coil spring is higher than the cavity resonance frequency.
5. The hermetic electric compressor of claim 1 , wherein the coil spring has a top-bottom symmetry with respect to the center.
6. The hermetic electric compressor of claim 1 , further comprising a hydrocarbon refrigerant which is free of chlorine, fluorine.
7. The hermetic electric compressor of claim 1 , wherein
among the designing models each of which having different cavity resonance frequency or electric compression element of different weight, the coincidence in resonance frequency between the coil spring and the cavity, or the mechanical vibration, can be avoided by replacing the coil spring with other one.
8. The hermetic electric compressor of claim 1 , further provided with a snubber protruding from the electric compression element side and a snubber protruding from the sealed container side, which snubber is to be inserted to the coil spring at both ends; wherein
among the designing models each of which having different cavity resonance frequency or electric compression element of different weight, the coincidence in resonance frequency between the coil spring and the cavity can be avoided by changing length of a portion of the snubber, which portion making contact with inner diameter of the coil spring.
9. A refrigeration unit comprising a compressor, a condenser, a drier, an expansion device and an evaporator; wherein
the compressor is a hermetic electric compressor comprising:
a sealed container, and
a plurality of coil spring for elastically supporting an electric compression element housed within the sealed container from bottom of the sealed container; wherein
the coil spring mounted with the electric compression element has an uneven pitch so that self-resonance frequency of the coil spring mounted with the electric compression element does not coincide with resonance frequency of mechanical vibration caused by operation of the electric compression element.
10. The hermetic electric compressor of claim 1 , wherein
the peak of resonance frequency of the coil spring and the cavity resonance frequency are separated from each other for at least 100 Hz.
11. The hermetic electric compressor of claim 1 , wherein
resonance frequency of the coil spring is higher than the cavity resonance frequency.
12. The hermetic electric compressor of claim 1 , further comprising a hydrocarbon refrigerant which is free of chlorine, fluorine.
13. The hermetic electric compressor of claim 1 , wherein
among the designing models each of which having different cavity resonance frequency or electric compression element of different weight, the coincidence in resonance frequency between the coil spring and the cavity, or the mechanical vibration, can be avoided by replacing the coil spring with other one.
14. The hermetic electric compressor of claim 1 , further provided with a snubber protruding from the electric compression element side and a snubber protruding from the sealed container side, which snubber is to be inserted to the coil spring at both ends; wherein
among the designing models each of which having different cavity resonance frequency or electric compression element of different weight, the coincidence in resonance frequency between the coil spring and the cavity can be avoided by changing length of a portion of the snubber, which portion making contact with inner diameter of the coil spring.
15. A refrigeration unit comprising a compressor, a condenser, a drier, an expansion device and an evaporator; wherein
the compressor is a hermetic electric compressor comprising:
a sealed container, and
a plurality of coil spring for elastically supporting an electric compression element housed within the sealed container from bottom of the sealed container; wherein
the coil spring mounted with the electric compression element has an uneven pitch so that self-resonance frequency of the coil spring mounted with the electric compression element does not coincide with a cavity resonance frequency formed in a cavity within the sealed container by operation of the electric compression element.