Rotary compressor and refrigeration cycle device
A rotary compressor according to an embodiment includes a plurality of eccentric parts, a first balancer, and a second balancer. The plurality of eccentric parts include a first eccentric part, a second eccentric part, and a third eccentric part disposed to be aligned from one side to the other side. The second balancer is disposed on the other side of the first balancer. Angles between a direction of eccentricity of the first balancer and directions of eccentricity of the plurality of eccentric parts are configured to increase in an order of the third eccentric part, the second eccentric part, and the first eccentric part. Angles between a direction of eccentricity of the second balancer and directions of eccentricity of the plurality of eccentric parts are configured to increase in an order of the first eccentric part, the second eccentric part, and the third eccentric part.
1. A rotary compressor comprising:
a shaft rotatable around a central axis;
a plurality of compression mechanism units including a first compression mechanism unit, a second compression mechanism unit, and a third compression mechanism unit disposed to be aligned from one side to the other side in a central axis direction of the shaft;
a plurality of eccentric parts provided on the shaft and including a first eccentric part, a second eccentric part, and a third eccentric part corresponding to the first compression mechanism unit, the second compression mechanism unit, and the third compression mechanism unit;
a first balancer rotating together with the shaft; and
a second balancer disposed on the other side of the first balancer and rotating together with the shaft, wherein
angles between a direction of eccentricity of the first balancer with respect to the central axis of the shaft and directions of eccentricity of the plurality of eccentric parts with respect to the central axis of the shaft are configured to increase in an order of the third eccentric part, the second eccentric part, and the first eccentric part, and
angles between a direction of eccentricity of the second balancer with respect to the central axis of the shaft and directions of eccentricity of the plurality of eccentric parts with respect to the central axis of the shaft are configured to increase in an order of the first eccentric part, the second eccentric part, and the third eccentric part.
2. The rotary compressor according to claim 1 , wherein, when:
a ratio of a distance in the central axis direction between a center of gravity of the second eccentric part and a center of gravity of the third eccentric part to a distance in the central axis direction between a center of gravity of the first eccentric part and the center of gravity of the second eccentric part is k;
an angle between a direction of eccentricity of the third eccentric part with respect to the central axis of the shaft and the direction of eccentricity of the first balancer with respect to the central axis of the shaft is θ1(rad); and
an angle between the direction of eccentricity of the third eccentric part with respect to the central axis of the shaft and the direction of eccentricity of the second balancer with respect to the central axis of the shaft is θ2(rad),
arctan(A)−π/36≤θ1≤arctan(A)+π/36,
arctan(A)+π−π/36≤θ2≤arctan(A)+π+π/36, and
A=√3/(2k+1)
are satisfied.
3. The rotary compressor according to claim 1 , wherein the plurality of eccentric parts are disposed between the first balancer and the second balancer in the central axis direction.
4. The rotary compressor according to claim 1 , wherein an intermediate bearing supporting the shaft is disposed in a region in which a distance in the central axis direction is larger between a first region between the center of gravity of the first eccentric part and the center of gravity of the second eccentric part and a second region between the center of gravity of the second eccentric part and the center of gravity of the third eccentric part.
5. The rotary compressor according to claim 1 , further comprising:
an electric motor unit disposed on the one side of the plurality of compression mechanism units and rotationally driving the shaft;
a first bearing disposed on the one side of the plurality of compression mechanism units and supporting the shaft; and
a second bearing disposed on the other side of the plurality of compression mechanism units and supporting the shaft, wherein
the first balancer is disposed on the one side of the electric motor unit, and
the second balancer is disposed on the other side of the second bearing.
6. A refrigeration cycle device comprising:
the rotary compressor according to claim 1 ;
a radiator connected to the rotary compressor;
an expansion device connected to the radiator; and
a heat absorber connected to the expansion device.