Search

CN-122029358-A - Screw machine

CN122029358ACN 122029358 ACN122029358 ACN 122029358ACN-122029358-A

Abstract

A screw machine comprising a male rotor (3) and a female rotor (2) enclosed in a housing (4) or body, the male and female rotors counter-rotating within the housing or body. The body (4) comprises relatively shaped openings (41) and (42) into which the rotors are inserted and is closed on one delivery side by a delivery assembly (5) and on the other suction side by a suction assembly (6), the delivery side and suction side corresponding to the aforementioned openings, from which the gas (or air) passes through a suction duct formed between the two rotors, the rotation closing the suction duct and the compressed gas being pushed towards the delivery side. Between the transport assembly and the housing and between the suction assembly and the housing there are respective flanged suction engagement connectors (7) or transport engagement connectors (8) suitably shaped to accommodate the rotor shaft and coupled with the housing opening and the suction assembly or transport assembly. In association with these flanged connections, in the forming zone, the machine comprises a filled polymer insert covering the rotor-facing surface of the metal body.

Inventors

  • Enso Papi

Assignees

  • TM.I.C.工业热力机械压缩机股份公司

Dates

Publication Date
20260512
Application Date
20241008
Priority Date
20231009

Claims (13)

  1. 1. A screw machine comprising a male rotor (3) and a female rotor (2) enclosed in a housing (4) or body, the male rotor (3) and the female rotor (2) counter-rotating within the housing (4) or body, The body (4) comprising an opening (41) and an opening (42) shaped opposite to each other, into which opening (41) and opening (42) a rotor is inserted, and the body (4) being closed on one delivery side by a delivery assembly (5) and on the other suction side by a suction assembly (6), the delivery side and the suction side respectively corresponding to the aforementioned openings, The gas or the air passes from the inlet unit through an inlet duct formed between the two rotors, the rotation closes the inlet duct and the compressed gas is pushed towards the delivery side, Between the transport assembly and the housing and between the suction assembly and the housing there is a respective flanged suction engagement connection (7) or flanged transport engagement connection (8), the flanged suction engagement connection (7) or flanged transport engagement connection (8) being suitably shaped to accommodate a rotor shaft and to be coupled with a housing opening and the suction assembly or the transport assembly, In connection with these flanged joint connections, the machine comprises, in the forming zone, a filling polymer insert covering the rotor-facing surface of the metal body.
  2. 2. Screw machine according to claim 1, wherein the flanged suction engagement connection (7) comprises a substantially flat peripheral outline (71), inside which peripheral outline (71) there is a lowered zone (72) surrounding a hole (73) accommodating the rotor shaft, into which lowered zone (72) a first filling polymer insert (91) is inserted in a compression initiation zone on the suction plane in contact with the rotor.
  3. 3. Screw machine according to claim 2, wherein the first polymer is connected with a second peripheral filling insert (92), said second peripheral filling insert (92) overlapping said peripheral profile (71) of said flanged joint connection (7).
  4. 4. Screw machine according to claim 1, wherein the flanged conveying engagement connection (8) comprises a substantially flat peripheral contour (81), inside which peripheral contour (81) there is a lowered zone (82) surrounding a hole (83) accommodating the rotor shaft, into which lowered zone (82) the third filling polymer insert (93) is inserted for the rotor to act on and substantially completely covers.
  5. 5. Screw machine according to claim 4, wherein the third polymer filling insert is connected with a fourth peripheral filling insert (94), said fourth peripheral filling insert (94) overlapping said peripheral profile (81) of said flanged joint connection (8).
  6. 6. The screw machine of claim 1, wherein an annular polymer insert is positioned within a bore (84) that receives the rotor.
  7. 7. The screw machine of claim 6, wherein the annular insert is received in a suitable digging portion formed in an inner edge (85) of the bore of the flanged joint connector.
  8. 8. The screw machine of claim 1 wherein the insert is secured to the plate by mechanical fastening.
  9. 9. The screw machine of claim 1 wherein the insert is secured to the flanged joint connection using a specific sealant/glue.
  10. 10. The screw machine of claim 9 wherein grooves of different thickness and different depth are dug on the flanged joint connection as required with sealant bonding.
  11. 11. A screw machine according to claim 3, wherein the first and second inserts are configured as a single body.
  12. 12. The screw machine of claim 5 wherein the second insert and the third insert are configured as a single body.
  13. 13. A screw machine, characterized in that it comprises a compressor or an expander.

Description

Screw machine The present invention relates to screw machines, such as, for example, compressors or expanders. Screw compressors are a type of positive-displacement rotary compressor comprising two parallel rotors externally equipped with a plurality of helical profiles (screws) so as to interlock with each other. The two rotors are housed in a stator constituted by two longitudinally intersecting cylindrical members, inside which the rotors rotate with a clearance incapable of reducing beyond a certain limit. The rotor shafts are supported by bearings and, typically, one rotor guides the other rotor (oil filled compressor) by interlocking of the same helical profile. Sometimes both rotors can be controlled by a pair of external gears to avoid contact and friction (dry compressors) that would otherwise occur. During rotation, the profile of the screw exposes a suction port disposed at one end of the stator through which air or gas enters to fill the volume between the profiles themselves up to its maximum extension. On the opposite side, the profiles penetrating into each other reduce the volume and compress the gas enclosed therein until the delivery port is exposed. The operation of the screw compressor is based on the counter-rotating action of two helical rotors which compress the gas or air extracted from the suction duct and convey it towards the delivery duct. During this path, the space decreases and thus the pressure increases. Screw compressors are widely used due to the diffusion of the technology used in their construction. Many manufacturers and assemblers offer various models of such products, single stage, two stage for high pressure, with or without oil for "oil free" applications. The rotational speed of the motor may be different from the rotational speed of the conductor rotor because they are not only directly connected, but also connected by multiplication/reduction gears or pulley ratios when a belt is present. These types of industrial compressors provide compressed gas or air continuously, are very well controllable, are extremely efficient, and are quiet (in terms of operational safety, environmental protection, and noise emissions). Like the compressor, the screw expander comprises two counter-rotating rotors (male and female) connected to corresponding shafts that transmit motion to a generator. The fluid expands by rotating the rotor and travelling in the axial direction in the volume created between the lobes of the screw. The gas fills the volume between the screws, is isolated and is then vented in the low pressure delivery zone. Like the compressor, the expander includes a stator housing in which the rotor is housed, and in which expansion of the working fluid occurs. The expander has an inlet port and an outlet port (or flange) for connection to the apparatus. The component is typically obtained from a gray cast iron or ductile iron blank, but may be made from other materials. In these machines (expanders or compressors) seals are also used, the main function of which is to seal the working fluid outwards inside the casing and to confine the lubricating oil, if present, inside the machine or in a well-defined area of the machine, for example between the support bearing and the compression chamber, thus preventing any type of pollution. The lubrication system provides oil to the bearings and other mechanical components intended to be in contact in order to reduce internal friction and reduce localized temperatures. In such machines, the junction area between the rotor and the stationary body is a particularly critical area. In fact, there is a gap in this region, which may lead to internal leakage and subsequent efficiency losses. Therefore, in order to solve the disadvantage, the gap is reduced by limiting the space. On the other hand, excessive reduction of clearances, or thermal or mechanical transients that may occur in standard machines, often lead to abnormal contact, wear and seizing, thereby reducing efficiency and the service life of the machine over time. The present invention solves the above-mentioned problems by inserting into the screw machine a sacrificial filling insert, which is disposed at the junction zone between the rotor and the fixed body, which has a configuration similar to that of the sealing element, but with the main aim of improving the performance and reliability of the machine itself. One aspect of the present invention relates to a screw machine, such as for example a screw compressor or a screw expander, having the features of the appended claim 1. Further features of the invention are contained in the dependent claims. The features and advantages of the present invention will become more apparent from the following illustrative, but non-limiting, description of embodiments thereof, with reference to the accompanying schematic drawings in which: FIG. 1 illustrates in perspective and exploded view a screw compressor according to one of the cond