A driving structure of a three-axis multi-stage Roots pump comprises a pump body, wherein a gear end cover is mounted at one side of the pump body, an air outlet end moving bearing air sealing unit is mounted on the other side of the pump body, and the bearing end cover is mounted on the pump at the side of the pump body; a driving axis, a first driven axis and a second driven axis are further provided inside the pump body, and the driving axis is connected with the first driven axis and the second driven axis through the gear, respectively; and both ends of the driving axis, the first driven axis and the second driven axis are movably connected to an air inlet end gear mechanical seal driving unit and an air outlet end moving bearing air sealing unit, respectively. The present invention overcomes the deficiencies of the prior art, a fixed bearing limiting unit not only plays a radial supporting role, strengthens the rigidity of an independent axis, but also reduces the diameter of the axis, and at the same time, evenly distributes to the two axial ends in the axial deformation process, avoiding deformation in a single direction, reducing the amount of displacement by nearly half, and also improving the sealing efficiency of the system.

A shunt-enhanced compression and pulsation trap (SECAPT) for a screw compressor assists internal compression (IC), reduces gas pulsation and NVH, and improves off-design efficiency, without using a slide valve and/or a serial pulsation dampener. The SECAPT includes an inner casing (e.g., an integral part of the compressor chamber) and an outer casing (e.g., surrounding part of the inner casing near the compressor discharge port) forming at least one diffusing chamber with a nozzle and a feedback region that provides a feedback flow loop between the compressor chamber and the compressor discharge port. The SECAPT automatically compensates cavity pressure to meet different outlet pressures (hence eliminating under-compression and/or over-compression when the discharge port opens), partially recovers potential energy associated with the under-compression (UC), and traps and attenuates gas pulsations and noise before the discharge port opens.

A manufacturing method of an end plate of a pump that can remove a sag includes: punching a workpiece from a plate material, the workpiece being the end plate including a mounting seat including a fastener; forming a pressed trace surface by pressing an outer edge of an outer surface, when a surface, of both front and back surfaces of the punched workpiece, further from a sag formed on a cut end surface is the outer surface, and a surface, of both front and back surfaces of the punched workpiece, nearer to the sag is an inner surface. A section of the pressed trace surface disposed along an outer edge of the mounting seat is a fastening section. A section of the pressed trace surface other than the fastening section is a non-fastening section. A radial width of the fastening section is shorter than that of the non-fastening section.

A driving structure of a three-axis multi-stage Roots pump comprises a pump body, wherein a gear end cover is mounted at one side of the pump body, an air outlet end moving bearing air sealing unit is mounted on the other side of the pump body, and the bearing end cover is mounted on the pump at the side of the pump body; a driving axis, a first driven axis and a second driven axis are further provided inside the pump body, and the driving axis is connected with the first driven axis and the second driven axis through the gear, respectively; and both ends of the driving axis, the first driven axis and the second driven axis are movably connected to an air inlet end gear mechanical seal driving unit and an air outlet end moving bearing air sealing unit, respectively. The present invention overcomes the deficiencies of the prior art, a fixed bearing limiting unit not only plays a radial supporting role, strengthens the rigidity of an independent axis, but also reduces the diameter of the axis, and at the same time, evenly distributes to the two axial ends in the axial deformation process, avoiding deformation in a single direction, reducing the amount of displacement by nearly half, and also improving the sealing efficiency of the system.

A method for repairing a worn portion in an inner diameter surface of a bore of a cast iron part is disclosed. The inner diameter surface of the bore may have an original surface geometry prior to wear. The method may comprise forming a crescent-shaped pocket in the inner diameter surface of the bore to remove the worn portion, installing an insert in the crescent-shaped pocket, and post-machining the insert to form a crescent-shaped insert that is flush with the original surface geometry of the bore inner surface diameter.

Volumetric compressor (1) for collection and/or treatment equipment of material in liquid, solid, dusty or muddy form. The compressor (1) comprises an operative chamber (50), defining a suction section and an exhaust section of a first fluid, a first header (61) and a second header (62), which delimit said chamber (50) on opposite parts along a longitudinal axis (101). The compressor further comprises at least two rotors (80, 80) with lobes (81, 81) housed in the chamber (50), each rotor (80, 80) rotating about a rotation axis (108, 108) substantially parallel to said longitudinal axis (101). The lobes of each rotor develop according to a helical profile. Furthermore, each of the headers (61,62) defines at least one injection opening (71, 71,72,72) communicating with a feeding device (150) of a second fluid.

A compressor element of a screw compressor inlet side and an outlet side and two helical rotors, respectively a male rotor with a drive for the male rotor and a female rotor that is driven by the male rotor by means of synchronisation gearwheels with at least one synchronisation gearwheel on the male rotor, wherein the drive and synchronisation gearwheels of the male rotor are chosen such that, upon being driven with acceleration of the rotors without gas forces, the resulting mechanical drive force that is exerted by this drive and by this synchronisation gearwheel on the male rotor has an axial component that is directed from the outlet side to the inlet side and that the movement of the male rotor in the axial direction from the outlet side to the inlet side is fixed by means of a single axial single-acting or double-acting bearing.

A screw compressor comprising a compressor element with a housing in which two helical rotors are mounted on bearings by their shafts, and a gearboxwith a housing with a mounting surface that is built onto a mounting surface of the housing of the compressor element, and which is coupled in a torque-transmitting way to a shaft of at least one of the aforementioned rotors, whereby the compressor element is provided with an oil circuit with an input and an output for oil and a cooling jacket with an input and output for a coolant, wherein the aforementioned inputs and outputs for the oil and for the coolant are located in the aforementioned mounting surface of the housing of the compressor element, whereby these inputs and outputs connect to channels for the respective supply and removal of the oil and the coolant.

A method for repairing a worn portion in an inner diameter surface of a bore of a cast iron part is disclosed. The inner diameter surface of the bore may have an original surface geometry prior to wear. The method may comprise forming a crescent-shaped pocket in the inner diameter surface of the bore to remove the worn portion, installing an insert in the crescent-shaped pocket, and post-machining the insert to form a crescent-shaped insert that is flush with the original surface geometry of the bore inner surface diameter.

A scroll compressor is provided which comprises: a housing; a driving motor; an orbiting scroll rotated by the driving motor; a fixed scroll; a suction port provided-in the housing and suctioning a refrigerant; an oil separator in the housing at one side of the fixed scroll; and a discharge port for discharging, to the outside of the housing, the refrigerant from which oil is separated in the oil separator. The scroll compressor includes an intermediate housing; a back pressure chamber in the intermediate housing at one side of the orbiting scroll, first and second back pressure seal members in the intermediate housing; a plurality of anti-rotation rings in the intermediate housing; and a plurality of anti-rotation pins at the orbiting scroll to be inserted into each of the plurality of anti-rotation rings.