An oil-free screw compressor

Abstract

The present invention discloses an oil-free screw compressor, comprising a main housing, a male screw and a female screw arranged in parallel, and water injection holes extending along the axial direction are arranged at the ends of the male screw and the female screw, and cooling water is brought into the bottom of the water injection hole through a water pipe inserted into the water injection hole and flows out from the orifice of the water injection hole to form a first cooling water path, which effectively cools the male screw, the female screw and the compression chamber during operation, and a second cooling water tank is arranged between the cylinder body and the exhaust port to strengthen the cooling of the main housing and the exhaust gas. The oil-free screw compressor is cooled by two cooling water paths, and the problem of high temperature of the screw and the casing of the dry screw compressor during operation is solved without cooling the compression chamber by spraying oil or other liquids.

Description

Technical Field

[0001] The invention relates to the field of screw compressors, and in particular to an oil-free screw compressor. Background Art

[0002] The screw compressor is composed of a pair of parallel, intermeshing female and male screws, and is the most widely used type of rotary compressor. Screw compressors can generally be divided into two types: dry type and wet type. The so-called dry type means that no liquid is sprayed in the compression chamber, and the compressed gas will not be contaminated. The wet type means that lubricating oil or other liquids are sprayed into the compression chamber to cool the compressed gas, improve the seal, and lubricate the female and male rotors and bearings to achieve self-transmission. The wet type is widely used, simple in structure, easy to maintain, stable and reliable, and is commonly used in aerodynamic engineering. However, the wet screw machine needs to add a high-precision filter to remove oil or other liquid impurities in the compressed air to obtain higher quality compressed gas. Although the dry screw compressor can directly output high-quality compressed gas, it does not have oil cooling in the compression chamber compared to the wet screw compressor, resulting in higher temperatures of the screw and the casing. Due to poor cooling performance, long-term high-temperature operation reduces the service life of the dry screw machine. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide an oil-free screw compressor with good cooling performance and simple structure.

[0004] The technical solution adopted by the present invention to solve the above technical problems is: an oil-free screw compressor, comprising a main housing, a male screw and a female screw arranged in parallel, the male screw is sleeved with convex teeth, the female screw is sleeved with concave teeth, a compression chamber for accommodating the convex teeth and the concave teeth is provided in the main housing, and an air inlet and an exhaust port communicating with the compression chamber are also provided on the main housing, characterized in that:

[0005] A first cooling water tank is also provided in the main shell body, and water injection holes connected to the first cooling water tank are respectively provided at the ends of the male screw and the female screw. The water injection holes are respectively coaxially arranged with the male screw and the female screw and extend axially. A first drain port and two first water inlets connected to the first cooling water tank are also provided at the end of the main shell body. Water pipes are respectively connected to the two first water inlets. The water pipes are inserted into the water injection holes and extend axially to the bottom of the water injection holes.

[0006] Preferably, one end of the female screw is the driving end, the male screw is also provided with a synchronous driven gear, the female screw is also provided with a synchronous driving gear, the synchronous driving gear is meshed with the synchronous driven gear, the main housing comprises a front end cover, a cylinder body and a rear end cover which are connected in sequence laterally, an oil filling bin is provided in the front end cover, the synchronous driving gear and the synchronous driven gear are arranged in the oil filling bin, the compression chamber is arranged in the cylinder body, the first cooling water bin is arranged in the rear end cover, the male screw and the female screw are also respectively provided with bearings for supporting purposes, the bearings comprise a first bearing and a second bearing.

[0007] Preferably, there are two first bearings, which are respectively located between the synchronous driven gear and the convex tooth, and between the synchronous driving gear and the concave tooth. Bearing pressure plates for fixing the first bearings are also respectively provided at the interval between the first bearing and the synchronous driven gear, and at the interval between the first bearing and the synchronous driving gear.

[0008] Preferably, a labyrinth seal and a shaft sleeve are sequentially arranged between the first bearing and the convex teeth from inside to outside along the axial direction of the male screw, and a first skeleton seal for sealing is arranged between the shaft sleeve and the inner wall of the front end cover.

[0009] Preferably, a labyrinth seal and a shaft sleeve are sequentially arranged between the first bearing and the concave teeth from inside to outside along the axial direction of the female screw, and a first skeleton seal for sealing is arranged between the shaft sleeve and the inner wall of the front end cover.

[0010] Preferably, the second bearings are provided with two and are located inside the rear end cover, supporting the male screw and the female screw respectively. A second skeleton seal is provided between one of the second bearings and the concave teeth, and a third skeleton seal is provided between the second bearing and the first cooling water bin, and a second skeleton seal is also provided between the other second bearing and the convex teeth, and a third skeleton seal is also provided between the second bearing and the first cooling water bin.

[0011] Preferably, the front end cover is provided with an oil inlet and a temperature measuring hole connected to the oil filling bin.

[0012] Preferably, a second cooling water tank is further provided in the main shell, and a second water inlet and a second water outlet communicating with the second cooling water tank are provided on the main shell.

[0013] Preferably, the second cold water cooling chamber is arranged between the exhaust port and the compression chamber.

[0014] Preferably, the second cooling water tank includes a water inlet tank and a water outlet tank extending along the axis, the water inlet tank and the water outlet tank are arranged in parallel and spaced apart, one end of the water inlet tank is connected to the second water inlet, and the other end is connected to the water outlet tank, and the water outlet tank is connected to the second drain outlet away from the end connected to the water inlet tank.

[0015] Compared with the prior art, the advantage of the present invention lies in that an axially extending water injection hole is provided at the end of the male screw and the female screw, and cooling water is brought into the bottom of the water injection hole through a water pipe inserted into the water injection hole and flows out from the orifice of the water injection hole to form a first cooling water path, which effectively cools the male screw, the female screw and the compression chamber during operation, and a second cooling water tank is provided between the cylinder body and the exhaust port to strengthen the cooling of the main shell and the exhaust gas. The oil-free screw compressor is cooled by two cooling water paths, and the problem of high temperature of the screw and the casing of the dry screw compressor during operation is solved without spraying oil or other liquids into the compression chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the novel oil-free screw compressor of the present invention.

[0017] Figure 2 It is a side view of the novel oil-free screw compressor of the present invention.

[0018] Figure 3 It is a cross-sectional view of the novel oil-free screw compressor of the present invention.

[0019] Figure 4 It is a partial structural cross-sectional view of the novel oil-free screw compressor of the present invention.

[0020] Figure 5 It is a bottom view of the novel oil-free screw compressor of the present invention.

[0021] Figure 6 It is a cross-sectional view of the second cold water tank in the novel oil-free screw compressor of the present invention. DETAILED DESCRIPTION

[0022] The present invention is further described in detail below with reference to the accompanying drawings.

[0023] like Figure 1 , Figure 2 and Figure 4 An oil-free screw compressor shown includes a main housing, a male screw 5 and a female screw 6 arranged in parallel, the main housing includes a front cover 1, a cylinder body 2 and a rear cover 3 connected in sequence transversely, the front cover 1 and the cylinder body 2 are connected and fixed by bolts, and the rear cover 3 and the cylinder body 2 are also connected and fixed by bolts. One end of the female screw 6 is a driving end 63, which passes through the main housing and is connected to an external power device.

[0024] An oil filling bin 13 is provided in the front end cover 1, a synchronous driven gear 51 and a convex tooth 52 are provided on the male screw 5, a synchronous driving gear 61 and a concave tooth 62 are provided on the female screw 6, the convex tooth 52 and the concave tooth 62 are meshed with each other, the synchronous driving gear 61 is meshed with the synchronous driven gear 51, and the synchronous driving gear 61 and the synchronous driven gear 51 are arranged in the oil filling bin, and the front end cover 1 is also provided with an oil inlet 11 and a temperature measuring hole 12 connected to the oil filling bin 13, the oil inlet 11 is used to inject lubricating oil into the oil filling bin 13, the lubricating oil can reduce the transmission friction of the synchronous driving gear 61 and the synchronous driven gear 51 in the oil filling bin 13 and enhance heat dissipation, and the temperature measuring hole 12 is used to insert a temperature measuring element into the oil filling bin 13 to monitor the operating temperature of the synchronous driving gear 61 and the synchronous driven gear 51.

[0025] A compression chamber 24 is provided in the cylinder body 2, and the compression chamber 24 accommodates the convex teeth 52 on the male screw 5 and the concave teeth 62 on the female screw 6. The cylinder body 2 is also provided with an air inlet 21 and an exhaust port 22 connected to the compression chamber 24. The air inlet 21 is located at the top of the cylinder body 2, and the exhaust port 22 is located at the bottom of the cylinder body 2.

[0026] The male screw 5 and the female screw 6 are also respectively sleeved with bearings for supporting purposes, and the bearings include a first bearing 81 and a second bearing 82. There are two first bearings 81, one is arranged between the synchronous driven gear 51 and the convex tooth 52, and a bearing pressure plate is arranged at the interval between the first bearing 81 and the synchronous driven gear 51, and the other first bearing 81 is arranged between the synchronous driving gear 61 and the concave tooth 62, and a bearing pressure plate for fixing the first bearing 81 is also arranged at the interval between the first bearing 81 and the synchronous driving gear 61. A labyrinth seal 83 and a shaft sleeve 84 are sequentially sleeved from the inside to the outside along the axial direction of the male screw 5 between the first bearing 81 sleeved on the male screw 5 and the convex tooth 52, and a first skeleton seal 85 for sealing is arranged between the shaft sleeve 84 and the inner wall of the front end cover 1 to play a sealing role. Similarly, a labyrinth seal 83 and a sleeve 84 are sequentially sleeved between the first bearing 81 sleeved on the female screw 6 and the concave tooth 62 along the axial direction of the female screw 6 from the inside to the outside, and a first skeleton seal 85 for sealing is also arranged between the sleeve 84 and the inner wall of the front end cover 1 to play a sealing role. There are two second bearings 82 in total and they are located inside the rear end cover 3, supporting the male screw 5 and the female screw 6 respectively. A second skeleton seal 87 is arranged between one of the second bearings 82 and the concave tooth 62, and a third skeleton seal 88 is arranged between the second bearing 82 and the first cooling water bin 33. A second skeleton seal 87 is also arranged between the other second bearing 82 and the convex tooth 52, and a third skeleton seal 88 is also arranged between the second bearing 82 and the first cooling water bin 33. The second skeleton seal 87 and the third skeleton seal 88 are used for sealing gas and liquid.

[0027] like Figure 3 and Figure 4 As shown, a first cooling water bin 33 is provided in the end cover 3, and water injection holes 7 are respectively provided at the ends of the male screw 5 and the female screw 6 near the rear end cover 3. The water injection holes 7 and the first cooling water bin 33 are coaxially arranged with the male screw 5 and the female screw 6 and extend axially to exceed the compression chamber 24. The rear end cover 3 is also provided with a first drain port 31 and two first water inlets 32 connected to the first cooling water bin 33. The two first water inlets 32 are respectively connected with a water pipe 71 inserted into the water injection hole 7 and extending axially along the water injection hole 7. The outer diameter of the water pipe 71 is smaller than the inner diameter of the water injection hole 7. The water pipe 71 extends beyond the compression chamber 24. The end of the water pipe 71 extends into the bottom of the water injection hole 7 and a gap is provided between the end of the water pipe 71 and the bottom of the water injection hole 7. Preferably, in this embodiment, the water pipe 71 is made of a stainless steel pipe. External cooling water flows into the water injection hole 7 through the first water inlet 32 ​​and the water pipe 71, absorbs the heat generated by the male screw 5 and the female screw 6, and then flows into the first cooling water tank 33, and finally flows out from the first drain port 31, forming a first cooling water path for cooling the male screw 5 and the female screw 6.

[0028] like Figure 5 and Figure 6 As shown, a second cooling water tank 9 is also provided in the main shell body. The second cooling water tank 9 is arranged at the bottom of the cylinder body 2, between the exhaust port 22 and the compression chamber 24. The cylinder body 2 is provided with a second water inlet 91 and a second drain port 92 connected to the second cooling water tank 9. The second cooling water tank 9 includes a water inlet tank 93 and a water outlet tank 94 extending along the axis. The water inlet tank 93 and the water outlet tank 94 are arranged in parallel and spaced apart. One end of the water inlet tank 93 is connected to the second water inlet 91, and the other end is connected to the water outlet tank 94. The end of the water outlet tank 94 away from the water inlet tank 93 is connected to the second drain port 92. The cooling water enters the water inlet tank 93 from the second water inlet 91 and then flows to the end of the water inlet tank 93 and enters the water outlet tank 94, and finally flows out from the second drain port 92, forming a second cooling water path for cooling the main shell body and exhausting gas.

[0029] The present invention arranges axially extending water injection holes at the ends of the male screw and the female screw, and brings cooling water into the bottom of the water injection holes through a water pipe inserted into the water injection holes, and flows out from the orifices of the water injection holes to form a first cooling water path, which effectively cools the male screw, the female screw and the compression chamber during operation, and arranges a second cooling water tank between the cylinder body and the exhaust port to strengthen the cooling of the main shell and the exhaust gas. The oil-free screw compressor is cooled by two cooling water paths, and the problem of high temperature of the screw and the casing of the dry screw compressor during operation is effectively solved without spraying oil or other liquids into the compression chamber.

[0030] Although the preferred embodiments of the present invention are described in detail above, it should be clearly understood that various modifications and variations are possible for those skilled in the art. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An oil-free screw compressor, comprising a main housing, a male screw (5) and a female screw (6) arranged in parallel, wherein the male screw (5) is sleeved with a convex tooth (52), and the female screw (6) is sleeved with a concave tooth (62), and a compression chamber (24) for accommodating the convex tooth (52) and the concave tooth (62) is provided in the main housing, and an air inlet (21) and an air outlet (22) communicating with the compression chamber (24) are also provided on the main housing, characterized in that: A first cooling water bin (33) is also provided in the main shell, and water injection holes (7) communicating with the first cooling water bin (33) are respectively provided at the ends of the male screw (5) and the female screw (6), and the water injection holes (7) are respectively arranged coaxially with the male screw (5) and the female screw (6) and extend axially, and a first drain port (31) communicating with the first cooling water bin (33) and two first water inlets (32) are also provided at the ends of the main shell, and water pipes (71) are respectively connected to the two first water inlets (32), and the water pipes (71) are inserted into the water injection holes (7) and extend axially to the bottom of the water injection holes (7); one end of the female screw (6) is a driving end (63), and the The male screw rod (5) is also provided with a synchronous driven gear (51), and the female screw rod (6) is also provided with a synchronous driving gear (61), and the synchronous driving gear (61) meshes with the synchronous driven gear (51). The main housing comprises a front end cover (1), a cylinder body (2) and a rear end cover (3) which are connected in sequence in a transverse manner. An oil filling bin (13) is provided in the front end cover (1), and the synchronous driving gear (61) and the synchronous driven gear (51) are arranged in the oil filling bin (13). The compression chamber (24) is arranged in the cylinder body (2), and the first cooling water bin (33) is arranged in the rear end cover (3). The male screw rod (5) and the female screw rod (6) are also provided with a plurality of cooling water bins (33) and a plurality of cooling water bins (33) respectively. The sleeve is provided with bearings for supporting purposes, and the bearings include a first bearing (81) and a second bearing (82); there are two first bearings (81), which are respectively located between the synchronous driven gear (51) and the convex tooth (52), and between the synchronous driving gear (61) and the concave tooth (62); a bearing pressure plate for fixing the first bearing (81) is also provided at the interval between the first bearing (81) and the synchronous driven gear (51), and at the interval between the first bearing (81) and the synchronous driving gear (61); there are two second bearings (82) which are located inside the rear end cover (3), respectively supporting the male screw rod (5) and the female screw rod (6), one of which A second skeleton seal (87) is provided between the second bearing (82) and the concave tooth (62), and a third skeleton seal (88) is provided between the second bearing (82) and the first cooling water bin (33); a second skeleton seal (87) is also provided between another second bearing (82) and the convex tooth (52), and a third skeleton seal (88) is also provided between the second bearing (82) and the first cooling water bin (33); a second cooling water bin (9) is also provided in the main shell, and a second water inlet (91) and a second water outlet (92) connected to the second cooling water bin (9) are provided on the main shell; the second cooling water bin (9) is provided between the exhaust port (22) and the compression chamber (24);The second cooling water bin (9) comprises a water inlet bin (93) and a water outlet bin (94) extending along the axis, the water inlet bin (93) and the water outlet bin (94) are arranged in parallel and spaced apart, one end of the water inlet bin (93) is connected to the second water inlet (91), and the other end is connected to the water outlet bin (94), and the end of the water outlet bin (94) away from the end connected to the water inlet bin (93) is connected to the second drain port (92).

2. The oil-free screw compressor according to claim 1, characterized in that: A labyrinth seal (83) and a shaft sleeve (84) are arranged in sequence from the inside to the outside along the axial direction of the male screw (5) between the first bearing (81) and the convex tooth (52), and a first skeleton seal (85) for sealing is arranged between the shaft sleeve (84) and the inner wall of the front end cover (1).

3. The oil-free screw compressor according to claim 1, characterized in that: A labyrinth seal (83) and a shaft sleeve (84) are arranged in sequence from the inside to the outside along the axial direction of the female screw (6) between the first bearing (81) and the concave tooth (62), and a first skeleton seal (85) for sealing is arranged between the shaft sleeve (84) and the inner wall of the front end cover (1).

4. The oil-free screw compressor according to claim 1, characterized in that: The front end cover (1) is provided with an oil inlet (11) and a temperature measuring hole (12) connected to the oil filling bin (13).

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