A compressor unit includes a compressor body including a compression mechanism, and an accumulator connected to the compressor body. The compression mechanism includes a cylinder, a piston to rotate eccentrically in the cylinder, and a blade partitioning an interior of a compression chamber of the cylinder into low and high pressure chambers. A frequency one time an operation frequency n of the compressor body and a frequency three times the operation frequency n of the compressor body are a 1n frequency and a 3n frequency, respectively. A phase difference ? between a phase of a transfer function of the 1n frequency of the accumulator and a phase of a transfer function of the 3n frequency of the accumulator is ?20?????60? with respect to a peak of the 1n frequency where the phase lag is positive, at a maximum number of revolutions of the compressor body.

A compressor unit includes a compressor body including a compression mechanism, and an accumulator connected to the compressor body. The compression mechanism includes a cylinder, a piston to rotate eccentrically in the cylinder, and a blade partitioning an interior of a compression chamber of the cylinder into low and high pressure chambers. A frequency one time an operation frequency n of the compressor body and a frequency three times the operation frequency n of the compressor body are a 1n frequency and a 3n frequency, respectively. A phase difference ? between a phase of a transfer function of the 1n frequency of the accumulator and a phase of a transfer function of the 3n frequency of the accumulator is ?20?????60? with respect to a peak of the 1n frequency where the phase lag is positive, at a maximum number of revolutions of the compressor body.

A scroll compressor is provided that may include a casing including a rotational shaft, a first scroll rotated by rotation of the rotational shaft, the first scroll including a first head plate and a first wrap that extends from the first head plate in a first direction, and a second scroll that defines a plurality of compression chambers together with the first scroll, the second scroll including a second head plate and a second wrap that extends from the second head plate in a second direction. Each of the first and second wraps spirally may extend from an outer end toward an inner start end, and the first wrap may have a thickness greater than a thickness of the second wrap.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have an elongate first island disposed thereon. The first island can have a body with a volume generally defined between front and rear surfaces that are spaced apart. The front and rear surfaces can lie in a plane parallel to a radial axis R. The perimeters of the front and rear surfaces can define a curved perimeter surface therebetween. The disclosure further provides embodiments having stationary islands and casings that rotate about the island.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have an elongate first island disposed thereon. The first island can have a body with a volume generally defined between front and rear surfaces that are spaced apart. The front and rear surfaces can lie in a plane parallel to a radial axis R. The perimeters of the front and rear surfaces can define a curved perimeter surface therebetween. The disclosure further provides embodiments having stationary islands and casings that rotate about the island.

A variable displacement vane pump and a power steering can secure a discharge flow rate when a steering wheel is turned, and restrict the discharge flow rate when the steering wheel is not turned. In the variable displacement vane pump and power steering system, a bypass line is formed. The bypass line causes a hydraulic fluid in a high pressure chamber of a control valve, which controls an eccentricity of a cam ring, to flow directly to a low pressure chamber side of the control valve. The hydraulic fluid flows directly to the low pressure chamber side of the control valve when the steering wheel is turned.

A variable displacement vane pump and a power steering can secure a discharge flow rate when a steering wheel is turned, and restrict the discharge flow rate when the steering wheel is not turned. In the variable displacement vane pump and power steering system, a bypass line is formed. The bypass line causes a hydraulic fluid in a high pressure chamber of a control valve, which controls an eccentricity of a cam ring, to flow directly to a low pressure chamber side of the control valve. The hydraulic fluid flows directly to the low pressure chamber side of the control valve when the steering wheel is turned.

A scroll type positive displacement assembly includes a first scroll and a second scroll, where the second scroll is configured to orbit with respect to a center of the first scroll without rotating with respect to the first scroll. Together, the first scroll and the second scroll define a compression chamber between two seal points where the first scroll and the second scroll contact one another as the second scroll orbits with respect to the first scroll during a compression cycle, and the two seal points come together proximate to a discharge port between the first scroll and the second scroll such that there is at least substantially no dead space between the first scroll and the second scroll at an end of the compression cycle. For example, the two seal points remain in sealing contact during at least one hundred and eighty (180) degrees of the compression cycle.

A scroll type positive displacement assembly includes a first scroll and a second scroll, where the second scroll is configured to orbit with respect to a center of the first scroll without rotating with respect to the first scroll. Together, the first scroll and the second scroll define a compression chamber between two seal points where the first scroll and the second scroll contact one another as the second scroll orbits with respect to the first scroll during a compression cycle, and the two seal points come together proximate to a discharge port between the first scroll and the second scroll such that there is at least substantially no dead space between the first scroll and the second scroll at an end of the compression cycle. For example, the two seal points remain in sealing contact during at least one hundred and eighty (180) degrees of the compression cycle.

The disclosure provides rotary machines that include, in one embodiment, a rotatable shaft defining a central axis A, the shaft having a first end and a second end. The shaft can have an elongate first island disposed thereon. The first island can have a body with a volume generally defined between front and rear surfaces that are spaced apart. The front and rear surfaces can lie in a plane parallel to a radial axis R. The perimeters of the front and rear surfaces can define a curved perimeter surface therebetween. The disclosure further provides embodiments having stationary islands and casings that rotate about the island.