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 gear for a pump includes a gear body defining a root circle, and a plurality of gear teeth extending from the gear body radially outwardly of the root circle. Each of the plurality of gear teeth have a tip portion, a leading edge, a trailing edge, a circular thickness defined between the leading edge and the trailing edge, a first radially outwardly facing surface and a second radially outwardly facing surface. At least one of the first radially outwardly facing surface and the second radially outwardly facing surface includes a chamfered portion that extends from the leading edge toward the trailing edge across a portion of the circular thickness.

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.

Disclosed are a sealing structure and a scroll air compressor having the same. The sealing structure includes: an orbiting scroll including an orbiting scroll spiral tooth (11), the orbiting scroll spiral tooth (11) being provided with an orbiting scroll spiral tooth groove (12), an orbiting scroll wear-resistant sealing strip (30) being provided in the orbiting scroll spiral tooth groove (12); a stationary scroll including a stationary scroll spiral tooth (21) matched with the orbiting scroll spiral tooth (11), the stationary scroll spiral tooth (21) being provided with a stationary scroll spiral tooth groove (22), a stationary scroll wear-resistant sealing strip (40) is provided in the stationary scroll spiral tooth groove (22), the wear-resistant sealing strip (30) is divided into sections including a high-temperature and high-pressure section (30a) and a medium-temperature and medium-pressure section (30b). The sealing structure reduces costs of use and maintenance of the sealing strip; a buffer contact surface of the wear-resistant sealing strip (30) in contact with a scroll surface is flat, which improves performances of sealing and noise-reduction; a bottom surface of the wear-resistant sealing strip (30) is equipped with a sealing ring having a cross section in a shape of a circle or a circular tube, which improves the damping and buffering performances; thereby the performance of the air compressor is improved, and the use cost of the air compressor is also reduced.

A compressor may include a non-orbiting scroll, an orbiting scroll, a driveshaft and an Oldham coupling. The orbiting scroll meshingly engages the non-orbiting scroll. The driveshaft includes a crankpin engaging the orbiting scroll and driving the orbiting scroll in an orbital path relative to the non-orbiting scroll. The Oldham coupling may include an annular body and a plurality of first keys extending from the annular body and slidably received in slots formed in the orbiting scroll. Each of the first keys may include a first post and a first cap covering at least a portion of the first post. The first posts may be integrally formed with the annular body from a first material. The first caps may be attached to the first posts and formed from a second material.

A rotary compressor 1 comprises a cylindrical housing 8, a cylindrical roller 10 accommodated in the housing 8, a motor shaft 13 leading through the roller 10 having a cam 14 for rolling the roller 10 along a side wall 15 of the housing 8, and a discharge port 18 leading through a bottom cover 12, wherein a height-to-radius ratio hr/rr of the roller 10 is between 0.6 and 1.2, a radius rs of the motor shaft 13 is 8.0 mm or less, a cam height he of 14 mm or less, an area Q of the discharge port 18 of 17 mm.sup.2 or more, and a thickness d of the discharge port 18 of 2.5 mm or less. For operation of the compressor 1, a top cover 19 may be put onto the top open side of the housing 8. The top cover 19 may have a bushing for the shaft 13. A heat pump P comprises the compressor 1. A household appliance H, in particular laundry care apparatus H, comprises the heat pump P.

A vane pump with a pump housing in which a cam ring is constructed or arranged, and wherein a rotor is provided that is mounted in the cam ring so that it can rotate about a rotational axis , wherein the cam ring has an inner contour with a variable radius that varies between a maximum radius and a minimum radius in the circumferential direction about the rotational axis , wherein, in the radial gap between the inner contour and the rotor , a number of lift sections is constructed with pump chambers constructed in these sections, and wherein vane elements are mounted on the rotor , wherein these elements slide against the inner contour of the cam ring and limit the pump chambers in the circumferential direction. According to the invention, the radius of the inner contour varies about the rotational axis according to the function: r=r.sub.0+a.Math.sin(n.Math.φ), where r.sub.0=(r.sub.max+r.sub.min)/2, a =(r.sub.max−r.sub.min)/2, and φ=phase angle of the radius (r) between (r.sub.min) and (r.sub.max) in the direction of rotation of the rotor .

A screw compressor slide valve with gas pulsation attenuation function includes valve walls and internal through holes. A screw compressor includes the screw compressor slide valve. A part of exhausted gas of the screw compressor is directly discharged from an exhaust port to an exhaust chamber to form a main exhaust flow channel; another part of the exhausted gas is discharged from the exhaust port into the exhaust chamber after being delayed by the internal through holes, which forms a branched exhaust flow channel. Since the branched exhaust flow channel is longer than the main exhaust flow channel, when the gas pulsation in the branched exhaust flow channel lags behind that in the main exhaust flow channel by 180-degree in phase, two gas pulsations in the two flow channels are offset due to opposite gas pulsation phases, which attenuates the gas pulsation, thereby suppressing induced vibration and noise.

A gear for a pump includes a gear body defining a root circle, and a plurality of gear teeth extending from the gear body radially outwardly of the root circle. Each of the plurality of gear teeth have a tip portion, a leading edge, a trailing edge, a circular thickness defined between the leading edge and the trailing edge, a first radially outwardly facing surface and a second radially outwardly facing surface. At least one of the first radially outwardly facing surface and the second radially outwardly facing surface includes a chamfered portion that extends from the leading edge toward the trailing edge across a portion of the circular thickness.

The present disclosure relates to a field of scroll compressors, and more particularly to a muffler device and a compressor with the muffler device. In one embodiment, a muffler device includes a sound hood inside which an expanding cavity is defined, and a microporous plate which is disposed inside the expanding cavity and divides the expanding cavity into a first cavity body and a second cavity body, and a plurality of through holes are provided in the microporous plate such that the air flow entering the expanding cavity exits the expanding cavity after passing through the plurality of through holes of the microporous plate. The muffler device and the compressor with the muffler device provided herein may effectively reduce the noise of the scroll compressor, especially pneumatic noise.