compressor

Abstract

A compressor (10) comprising a revolving subassembly (12) comprising an elongated helical revolving sub (14) having an axial cylindrical cavity (16) therethrough, a stationary shaft (18) axially aligned with the revolving sub (14) and passing through the cavity (16), a housing (20) for containing the revolving sub (14) and its associated stationary shaft (18) therein, wherein the shaft (18) is fixed within the housing (20), and a bearing arrangement (22) mounted within the cavity (16) of the revolving sub (14) for bearing friction between the revolving sub (14) and the shaft (18) as the revolving sub (14) rotates about the stationary shaft (18).

Description

Technical Field

[0001] This invention relates to a screw compressor. Summary of the Invention

[0002] According to the present invention, a compressor is provided, the compressor comprising:

[0003] A male rotor assembly, comprising:

[0004] A long, helical male rotor with an axial cylindrical cavity passing through it;

[0005] A fixed shaft, axially aligned with the male rotor, passes through the cavity;

[0006] A housing for accommodating the male rotor and its associated fixed shaft, wherein the shaft is fixed within the housing to prevent rotation relative to the housing;

[0007] A bearing assembly is installed in the cavity of the male rotor to withstand the friction between the rotor and the shaft when the male rotor rotates about the fixed shaft;

[0008] A female rotor assembly, comprising:

[0009] A long, helical female rotor is aligned with the male rotor and has an axial cylindrical cavity passing through it;

[0010] A fixed shaft, axially aligned with the mother rotor, passes through the cavity;

[0011] The housing also houses the female rotor and its associated fixed shaft, wherein the shaft is fixed within the housing to prevent rotation relative to the housing;

[0012] A bearing assembly is installed in the cavity of the female rotor to withstand the friction between the rotor and the shaft when the female rotor rotates around the fixed shaft;

[0013] The complementary helical structure defines the cavity between the male and female structures, which captures, drives, and compresses fluid material forward when the rotor is driven.

[0014] The rotor can be made of any suitable material, including composite alloys, titanium, molybdenum, etc., preferably low-carbon steel. It should be understood that any suitable manufacturing process can be used to manufacture the rotor, preferably casting and / or machining. One end of the male or female rotor can be configured to allow a drive unit to be mounted on the rotor. The drive unit can be in any suitable form and can be belt-driven, chain-driven, or a motor, preferably a motor. It should be understood that the drive unit is mounted directly on the rotor without transmission loss.

[0015] The fixed shaft can be made of any suitable material, but is preferably low-carbon steel.

[0016] The housing can be made of any suitable material, preferably steel. The housing may include a fixing device for securing the shaft to the housing. The fixing device may be configured to secure at least one end of the male or female shaft to the housing such that its opposite free end allows one end of the corresponding rotor to be received by the drive device. The fixing device may be in the form of any suitable fixing device, preferably a lock nut. The lock nut may be configured to allow axial adjustment of the shaft. It should be understood that the housing can be manufactured using any suitable manufacturing process; preferably, the housing is cast and / or machined. The housing may define an opening at one end to receive the rotor and the shaft therein. The housing may define a hole at the end opposite its open end to allow at least a portion of one end of the male or female rotor and the shaft to protrude therefrom, such that the drive device can be mounted thereon and can be received by the drive device. The housing may also include a cover for covering the rotor and the shaft when they are received by the opening defined at one end of the housing. A fastening device, such as bolts, may be provided for securing the cover to the housing. The cover may define a through-hole to allow one end of a shaft to be secured to the housing to protrude through it. The securing device may secure the protruding end of the shaft through the cover to the cover. It should be understood that the securing device can be tightened and loosened for axial adjustment to adjust the interface gap between the male and female components, up to 20 micrometers, depending on the rotor's diameter and length, and to allow adjustment of the rotor's positioning within the housing. It should be understood that opposite ends of the shaft may be spaced apart from the housing using spacers.

[0017] The bearing assembly may include any suitable bearing, such as a standard bearing, a sliding bearing, etc., preferably a radial bearing and an axial thrust bearing. The axial thrust bearing may be located in the middle portion of the rotor cavity to prevent axial movement of the rotor due to suction. The radial bearing may be located at both ends of the rotor cavity to support the shaft at one end. The radial bearing may also be located in a portion of the rotor cavity, with the rotor's exterior housed within the housing in that portion. The bearing assemblies may be axially spaced within the rotor cavity to withstand friction between the rotor and the shaft along their axis. It should be understood that the interior of the bearing assembly is fixed to the fixed shaft to prevent rotation relative to the shaft, while the exterior of the bearing assembly allows free rotation relative to the shaft.

[0018] Multiple spacers can be mounted on a fixed shaft between the bearing assemblies. The spacers can be made of any suitable material, including steel, hardened composite materials, or metal composite materials, preferably steel. The spacers may include multiple inner spacer members and multiple outer spacer members coaxially aligned with each other. It should be understood that the inner spacer members are heat-pressed onto the fixed shaft to prevent rotation about the shaft and to support and reinforce the shaft and the rotor assembly to reduce bending and increase resistance to shear forces. It should be understood that one end of the bearing assembly and one end of the spacer are abutted and supported therebetween to support and reinforce the fixed shaft and the rotor assembly.

[0019] A lubrication system is in fluid communication with the bearing assembly. The lubrication system may include a lubricant and a lubrication channel defined by a shaft, the lubrication channel being in fluid communication with the bearing assembly for directing the lubricant to the bearing assembly for lubrication. The lubricant may be any suitable form of lubricant and may be selected from the group including greases, ISO 67 grade lubricants, etc. The lubrication channel may be defined by two ends of the shaft. The channel is in fluid communication with the bearing assembly. The lubrication channel at one end of the shaft may be an inlet channel allowing lubricant to flow into the rotor cavity to lubricate the bearing assembly. The channel at the opposite end of the shaft may be an outlet channel allowing lubricant to be removed from the rotor cavity.

[0020] Multiple seals may be installed within the rotor cavity to seal the bearing assembly and the spacer therein. The seals may be in the form of any suitable conventional seal. The interior of the seal may be fixed to the shaft to prevent rotation about the shaft. The exterior of the seal may rotate relative to the interior of the seal to allow the rotor cavity to remain sealed as the rotor rotates about the shaft. It should be understood that the seals prevent lubricant leakage from the rotor cavity. It should be understood that the seals seal the lubricant within the rotor cavity so that the lubricant does not come into contact with and contaminate the compressed material, preferably air. It should be understood that the seals also prevent lubricant, preferably water, from leaking into the rotor cavity from the compressor chamber.

[0021] A coupling device may be mounted on one end of the male or female rotor protruding from the housing, and its size, shape and configuration may be designed to receive one end of the shaft therein for directly coupling the drive device to the rotor.

[0022] It should be understood that the surfaces of the rotor assembly and its components may be plated with a nickel composition, molybdenum, polytetrafluoroethylene, or similar alloys to protect the surfaces from water-induced corrosion or abrasive wear from foreign materials. It should be understood that any suitable electroplating process can be used, preferably an electroless process. Attached Figure Description

[0023] The compressor according to the invention will now be described with reference to the accompanying drawings by way of the following non-limiting examples.

[0024] In the attached diagram:

[0025] Figure 1 This is a cross-sectional view of the compressor.

[0026] Figure 2 This is a cross-sectional view of the male and female rotors.

[0027] Figure 3 This is a cross-sectional view of the mother rotor. Detailed Implementation

[0028] Referring now to the accompanying drawings, reference numeral 10 generally refers to a compressor, which includes a male rotor assembly 12. The male rotor assembly 12 includes an elongated helical male rotor 14 having an axially cylindrical cavity 16 passing through it, a fixed shaft 18 axially aligned with the male rotor 14 and passing through the cavity 16, and a housing 20 for receiving the male rotor 14 and its associated fixed shaft 18. The shaft 18 is fixed within the housing 20 to prevent rotation relative to the housing 20. A bearing assembly 22 is mounted within the cavity 16 of the male rotor 14 to withstand friction between the rotor 14 and the shaft 18 as the male rotor 14 rotates about the fixed shaft 18. The compressor 10 further includes a female rotor assembly 24, which includes an elongated helical female rotor 26 having an axially cylindrical cavity 28 passing through it and aligned with the male rotor 14, and a fixed shaft 30 axially aligned with the female rotor 26 and passing through the cavity 28. The housing 20 also houses the female rotor 26 and its associated fixed shaft 30 therein. The shaft 30 is fixed within the housing 20 to prevent rotation relative to the housing 20. A bearing assembly 22 is mounted within the cavity 28 of the female rotor 26 to withstand friction between the rotor 26 and the shaft 30 as the rotor 26 rotates about the fixed shaft 30. A drive unit 32 drives either the male rotor 14 or the female rotor 26, wherein complementary helical structures 34a and 34b define a cavity between a male (convex) structure 34a and a (concave) structure 34b. When the rotors 14 and 26 are driven, the cavity captures, drives, and compresses fluid material (not shown) forward.

[0029] The rotors 14 and 26 are made of low-carbon steel. It should be understood that the rotors 14 and 26 are either cast or machined. One end 14a of the male rotor 14 is configured to allow the drive unit 36 ​​to be mounted on the rotor 14. The drive unit is in the form of a motor 36. It should be understood that the motor 36 is directly mounted on the rotor 14 without transmission loss.

[0030] The fixed shafts 18 and 30 are made of low carbon steel.

[0031] The housing 20 is made of steel. The housing 20 includes a fixing device 38 for securing the shafts 18, 30 to the housing 20. The fixing device 38 is configured to secure at least one end 18a of the male shaft 18 to the housing, such that the opposing free end 18b allows the corresponding rotor end 14b to be received by the motor 22. The fixing device 38 is in the form of a lock nut. The lock nut 38 is configured to allow axial adjustment of the shafts 18, 30. It should be understood that the housing 20 is cast or machined. The housing 20 defines an opening 40 at one end 20a to receive the rotors 14, 26 and the shafts 18, 30 therein. The housing 20 defines a hole (not shown) at the end 20b opposite the opening end 20a to allow at least a portion of the male rotor 14 and one end 14b of the shaft 18 to protrude therefrom, so that the motor 22 can be mounted therein and can be received by the motor 22. The housing 20 also includes a cover 42, which covers the rotors 14, 26 and the shafts 18, 30 when received by an opening 40 defined at one end 20a of the housing 20. Fastening devices, such as bolts, are used to secure the cover 42 to the housing 20. The cover 42 defines a through-hole (not shown) to allow one end 18a, 30a of the shafts 18, 30 to be secured to the housing 20 to protrude therethrough. A lock nut 38 secures the protruding ends 18a, 30a of the shafts 18, 30 through the cover 42 to the cover 42. It should be understood that the locking nut 42 is tightened and loosened for axial adjustment to adjust the interface gap between the male structure 34a and the female structure 34b, up to 20 micrometers, which varies depending on the diameter and length of the rotors 14, 26, and allows adjustment of the positioning of the rotors 14, 26 in the housing 20.

[0032] The bearing assembly 22 includes a radial bearing 22a and an axial thrust bearing 22b. The axial thrust bearing 22b is located in the middle of the rotor cavities 16, 28 and is used to prevent the rotors 14, 26 from moving axially due to suction. The radial bearing 22a is located at both ends of the rotor cavities 16, 28 and is used to support the shafts 18, 30 at one end. The radial bearing 22a1 is also located in a portion of the rotor cavity 16, where the outside of the rotor 14 is located in the housing 20. The bearings 22a, 22b, and 22a1 are axially spaced apart within the cavities 16, 28 of the rotors 14, 26 and are used to withstand friction along their axes between the rotors 14, 26 and the shafts 18, 30. It should be understood that the interior (not shown) of the bearings 22a, 22b, 22a1 is fixed to the fixed shafts 18, 30 to prevent rotation relative to the shafts 18, 30, while the exterior (not shown) of the bearing assembly 22a, 22b, 22a1 allows free rotation relative to the shafts 18, 30.

[0033] Multiple spacers 44 are mounted on fixed shafts 18 and 30 between bearings 22a, 22b, and 22a1. The spacers 44 are made of steel. Each spacer 44 includes multiple inner spacer members 44a and multiple outer spacer members 44b that are coaxially aligned with each other. It is understood that the inner spacers 44a are heat-pressed onto the fixed shafts 18 and 30 to prevent rotation about the shafts 18 and 30 and to support and reinforce the shafts 18 and 30 and the rotor assemblies 12 and 24 to reduce bending and increase resistance to shear forces. It should be understood that one end (not shown) of the bearings 22a, 22b, and 22a1 and one end (not shown) of the spacer 44 between them are adjacent to and supported by each other to support the shafts 18 and 30 and the rotor assemblies 12 and 24.

[0034] A lubrication system (not shown) is in fluid communication with the bearings 22a, 22b, 22a1. The lubrication system (not shown) includes a lubricant (not shown) and lubrication channels 46a, 46b defined by the shafts 18, 30, in fluid communication with the bearings 22a, 22b, 22a1 to guide the lubricant (not shown) toward the bearings 22a, 22b, 22a1 for lubrication. The lubricant (not shown) is in the form of an ISO 67 grade lubricant. The lubrication channels 46a, 46b are defined by two ends 18a, 18b, 30a, 30b of the shafts 18, 30. The channels 46a, 46b are in fluid communication with the bearings 22a, 22b, 22a1. The lubrication passage 46a at one end 18a, 30a of shafts 18, 30 is an inlet passage 46a, allowing ISO 67 grade lubricant (not shown) to flow into rotor cavities 16, 28 to lubricate bearings 22a, 22b, 22a1. The passage 46b at the opposite ends 18b, 30b of shafts 18, 30 is an outlet passage 46b, allowing ISO 67 grade lubricant (not shown) to be removed from rotor cavities 16, 28.

[0035] The seal 48 is installed within the rotor cavities 16, 28 to seal the bearings 22a, 22b, 22a1 and the spacer 44 therein. The seal 48 can be any suitable conventional seal. The interior 48a of the seal 48 is fixed to the shafts 18, 30 to prevent rotation about the shafts 18, 30. The exterior 48b of the seal 48 rotates relative to the interior 48a to allow the rotor cavities 16, 28 to remain sealed as the rotors 14, 26 rotate about the shafts 18, 30. It should be understood that the seal 48 prevents leakage of ISO 67 grade lubricant (not shown) from the rotor cavities 16, 28. It should be understood that the seal 48 seals the ISO 67 grade lubricant (not shown) within the cavities 16, 28 of the rotors 14, 26 so that the ISO 67 grade lubricant (not shown) does not come into contact with and contaminate compressed air (not shown). It should be understood that the seal 48 also prevents lubricant (not shown), preferably water, from leaking into the rotor chambers 16, 28 of the compressor in the compression chamber (not shown).

[0036] A coupling device 50 is mounted on one end 14b of the male rotor 14 protruding from the housing 20, the housing 20 being sized, shaped and configured to receive one end 18b of the shaft 18 therein to directly couple the motor 22 to the rotor 14.

[0037] It should be understood that the surfaces of the rotor assemblies 12, 24 are plated with nickel to protect them from corrosion caused by water or abrasive foreign materials. It should be understood that this is a non-electrical process.

[0038] Of course, it should be understood that the compressor 10 according to the present invention is not limited to the precise structural and functional details described above with reference to the accompanying drawings, and may be varied as needed.

[0039] Although only certain embodiments of the invention have been described herein, any person skilled in the art will understand that other modifications, variations, and possibilities are possible. Therefore, such modifications, variations, and possibilities are considered to fall within the spirit and scope of the invention and thus form part of the invention as described and / or illustrated herein. It should also be understood that the embodiments are provided to further illustrate the invention and assist those skilled in the art in understanding it, and are not intended to be unduly construed as limiting the reasonable scope of the invention.

[0040] The inventors believe that the compressor 10 according to the invention has the advantage of higher efficiency than other known rotors. Due to the fact that the rotors 14, 26 rotate about the shafts 18, 30, the rotor assemblies 12, 24 also experience less bending than other known rotors. Another advantage is the absence of transmission losses, as the motor 22 is directly mounted on the rotor 14 via the coupling device 50. Using water as a lubricant (not shown) for the rotors in the compression chamber is advantageous because it allows the rotor assemblies 12, 24 to operate at lower operating temperatures. Another advantage is that the closed lubrication system (not shown) allows for effective lubrication of the rotating elements, thus preventing wear on the rotating rotor assemblies 12, 24. Since the air drawn into the rotor assemblies 12, 24 is contaminated, the closed lubrication system (not shown) is also less sensitive to increases in the pH of the water, thus eliminating the need for a filtration system to filter and lower the pH of the water (not shown). The hollow rotors 14, 26 have lower rotor backlash and also allow for gaps between the rotors 14, 26 and the housing 20 and the cover 42. The bearings 22 and spacers 44 installed within the hollow rotors 14, 26 allow for a significant reduction in rotor bending caused by providing support for the shafts 18, 30. The compressor 10 according to the invention also has an expected lifespan two to three times longer than that of existing oil-free compressors.

Claims

1. A compressor, characterized in that: The compressor includes: A male rotor assembly, comprising: An axially adjustable elongated helical male rotor having a first axial cylindrical cavity passing through it; A first fixed shaft, axially adjustable, is axially aligned with the helical male rotor and passes through the first axial cylindrical cavity; and A first bearing assembly is used to rotatably connect the first axial cylindrical cavity and the helical male rotor. The first bearing assembly includes a first radial bearing and a first axial thrust bearing, wherein the first radial bearing is installed in both ends of the first axial cylindrical cavity, and the first axial thrust bearing and the first radial bearing are installed in a middle part of the first axial cylindrical cavity. A housing for accommodating the helical male rotor, and the housing also rotatably fixes the first fixed shaft within a first housing cavity of the housing; A female rotor assembly, comprising: An axially adjustable elongated helical female rotor is aligned with the helical male rotor and has a second axial cylindrical cavity passing through it; A second fixed shaft, axially adjustable, is axially aligned with the helical mother rotor and passes through the second axial cylindrical cavity; and A second bearing assembly is used to rotatably connect the second axial cylindrical cavity and the helical female rotor. The second bearing assembly includes a second radial bearing and a second axial thrust bearing, wherein the second radial bearing is installed in both ends of the second axial cylindrical cavity, and the second axial thrust bearing and the second radial bearing are installed in a middle part of the second axial cylindrical cavity. The housing further houses the helical female rotor, and the housing also rotatably fixes the second fixed shaft within the second housing cavity of the housing; The housing defines a hole at one end to allow at least a portion of one end of the helical male rotor or the helical female rotor and its associated shaft to protrude therefrom, such that a drive device can be mounted on or received by one end of the helical male rotor or the helical female rotor. The drive device is coupled to the helical male rotor or the helical female rotor; and The spiral male rotor and the spiral female rotor define a plurality of working cavities. When the spiral male rotor and the spiral female rotor are driven, the plurality of working cavities capture, drive and compress fluid material forward.

2. The compressor as described in claim 1, characterized in that: The housing includes a plurality of locking nuts for axially adjustable fixing of a plurality of shafts to the housing. The plurality of locking nuts are configured to fix one end of the first fixed shaft and the second fixed shaft to the housing, such that their opposite free ends can be received by the drive device.

3. The compressor as described in claim 1, characterized in that: The housing defines an opening opposite the hole to receive the first fixed shaft, the second fixed shaft, the helical male rotor, and the helical female rotor therein.

4. The compressor as described in claim 3, characterized in that: The housing includes a cover that covers the first fixed shaft, the second fixed shaft, the helical male rotor, and the helical female rotor when the first fixed shaft, the second fixed shaft, the helical male rotor, and the helical female rotor are received by an opening defined at one end of the housing.

5. The compressor as described in claim 1, characterized in that: The first axial thrust bearing and the second axial thrust bearing are respectively located in the first axial cylindrical cavity and the second axial cylindrical cavity, wherein the plurality of locking nuts allow axial adjustment and lock the helical male rotor or the helical female rotor in place.

6. The compressor as described in claim 1, characterized in that: The first radial bearing is located at both ends of the first axial cylindrical cavity and is used to support the two ends of the first fixed shaft.

7. The compressor as described in claim 1, characterized in that: The first radial bearing is located in a portion of the first axial cylindrical cavity, wherein the exterior of the helical male rotor is within the housing.

8. The compressor as described in claim 1, characterized in that: The first radial bearing and the second radial bearing are axially spaced apart in the first axial cylindrical cavity and the second axial cylindrical cavity, respectively.

9. The compressor as described in claim 1, characterized in that: Multiple spacers are installed on the first fixed shaft between the first radial bearing and the first axial thrust bearing, and on the second fixed shaft between the second radial bearing and the second axial thrust bearing.

10. The compressor as claimed in claim 1, characterized in that: A lubrication system is fluidly connected to the first bearing assembly and the second bearing assembly within the first axial cylindrical cavity and the second axial cylindrical cavity. The lubrication system includes a lubricant and a lubrication channel. The lubrication channel is defined by two ends of the first fixed shaft and the second fixed shaft and corresponding inlets and outlets. The inlets and outlets are fluidly connected to the first fixed shaft and the second fixed shaft in the first axial cylindrical cavity and the second axial cylindrical cavity, respectively.

11. The compressor as claimed in claim 10, characterized in that: Multiple seals are installed in the first axial cylindrical cavity and the second axial cylindrical cavity to seal the first bearing assembly and the second bearing assembly, respectively. The interior of the first seal is fixed to the first fixed shaft to prevent rotation about the first fixed shaft, and the exterior of the first seal is rotatable relative to the interior of the first seal to allow the first axial cylindrical cavity to remain sealed when the helical male rotor rotates about the first fixed shaft. The interior of the second seal is fixed to the second fixed shaft to prevent rotation about the second fixed shaft, and the exterior of the second seal is rotatable relative to the interior of the second seal to allow the second axial cylindrical cavity to remain sealed when the helical female rotor rotates about the second fixed shaft.

12. The compressor as claimed in claim 1, characterized in that: A coupling device is mounted on one end of the helical male rotor protruding from the housing. The coupling device is sized, shaped, and configured to receive one end of the helical male rotor therein, so as to directly couple the drive device to the helical male rotor. Alternatively, a coupling device may be installed at one end of the helical female rotor protruding from the housing, the coupling device being sized, shaped, and configured to receive one end of the helical female rotor therein, so as to directly couple the drive device to the helical female rotor.

13. The compressor as claimed in claim 1, characterized in that: Another first radial bearing is installed in the middle part of the first axial cylindrical cavity, and another second radial bearing is installed in the middle part of the second axial cylindrical cavity.

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