Oil-free screw compressor

Abstract

The utility model discloses an oil -free screw compressor, including cylinder body, air inlet end seat, exhaust end seat, air inlet end cover, exhaust end cover, male rotor and female rotor, one end fixed connection air inlet end seat of cylinder body, the other end fixed connection air inlet end cover of air inlet end seat, the other end fixed connection exhaust end seat of cylinder body, the other end fixed connection exhaust end cover of exhaust end seat, male rotor and female rotor set up in cylinder body and with air inlet end seat, exhaust end seat form working chamber, male rotor and female rotor are variable pitch rotor, the utility model discloses through make cylinder body, air inlet end seat, exhaust end seat, air inlet end cover, exhaust end cover standardization design has reduced enterprise spare burden, realizes content volume ratio adjustment through the pitch of male rotor and female rotor adjustment, has improved the production efficiency of spare parts, is helpful to the improvement of enterprise management and economic benefit.

Description

Technical Field

[0001] This utility model relates to the field of mechanical engineering design, specifically to an oil-free screw compressor. Background Technology

[0002] For twin-screw compressors, many parameters need to be determined during machine design, such as rotor diameter, rotor tooth ratio (common tooth ratios include 5 types: 3:4, 3:5, 4:6, 5:6, and 5:7), length-to-diameter ratio (commonly 3 levels: 1.1, 1.4, 1.65, etc.), internal volume ratio (commonly 6 levels: 1.5, 2.0, 2.5, 3.0, 3.5, and 4.0), orifice direction (commonly 2 types: top inlet / top outlet and top inlet / bottom outlet), and drive rotor (commonly male rotor drive, but can also be changed to female rotor drive). Usually, a compressor with the same rotor diameter and tooth ratio is considered a single model, and the other parameters are called different configurations of that model. During design, only one of each configuration can be selected for a compressor. Thus, the same model may have as many as 3*6*2*2 = 72 configurations; if different tooth ratios are considered, there are 5*72 = 360 configurations. While some components may be interchangeable for each configuration, key components are not.

[0003] Typically, for the same model with the same rotor diameter and the same tooth ratio, the rotor requires 3 configurations, the intake end seat requires 2 configurations, the exhaust end seat requires 12 configurations, the cylinder requires 36 configurations, and the exhaust end cover requires 2 configurations.

[0004] Among them, the intake end seat, exhaust end seat, cylinder, and exhaust end cover are shells, which are generally produced by casting. Theoretically, each component requires a mold.

[0005] Furthermore, when the size of the compressor is limited, the internal volume ratio needs to be adjusted for use. The conventional way to change the internal volume ratio is to change the size of the housing orifice, that is, the size of the intake and exhaust ports. When adjusting the size of the orifice, the size of the compressor's intake and exhaust end seats also needs to be adjusted, making the production of parts more complicated. The internal volume ratio is a key parameter of positive displacement compressors, which is the ratio of intake volume to exhaust volume, and directly affects the compressor's energy efficiency and operational stability.

[0006] In actual projects, using the wrong configuration can seriously damage efficiency and increase energy consumption. The losses caused by energy consumption often far exceed the production cost of the machine. Therefore, for energy conservation purposes, companies need to equip themselves with as many configurations as possible. This diversity of configurations greatly increases the inventory burden of companies, and there is an urgent need to develop a standardized compressor in order to adapt to a wider range of working conditions. Utility Model Content

[0007] To address the problems of inconsistent standards leading to numerous configurations, production chaos, and confusion in the production management of corresponding components when adjusting internal volume ratios in the existing technology, this utility model provides an oil-free screw compressor.

[0008] The technical solution adopted by this utility model to solve its technical problem is:

[0009] This utility model discloses an oil-free screw compressor, including a cylinder body, a male rotor, and a female rotor. One end of the cylinder body is fixedly connected to an inlet end seat, and the other end of the cylinder body is fixedly connected to an exhaust end seat. The male and female rotors are disposed within the cylinder body and form a working chamber with the inlet and exhaust end seats. The cylinder body has a symmetrical upper and lower structure, and auxiliary feet are symmetrically arranged on the outer wall of the cylinder body. The auxiliary feet can provide support for the cylinder body after rotating 180 degrees vertically. One end of the cylinder body is machined with a first air port that can cooperate with the exhaust end seat. The inlet end seat is symmetrically provided with bearing holes. An air inlet is provided above the air intake seat. A symmetrical passage port is provided on the side of the air intake seat that mates with the cylinder block. The air inlet and the passage port are connected, forming a double-wall structure for the air intake seat. A second air port mates with the first air port, and an exhaust port is provided that communicates with the second air port. Symmetrical support feet are provided on the outer wall of the exhaust seat, allowing the exhaust port to face upwards or downwards with the assistance of the support feet. The shaft of the male or female rotor extending from one end near the exhaust seat forms a power mechanism.

[0010] Preferably, the double-wall structure includes a gas channel, the air inlet and the air outlet are connected through the gas channel, the gas channel surrounds the bearing hole, the bearing hole can cooperate with the rotating shaft of the male rotor and the female rotor, the inner shell formed by the bearing hole and the gas channel and the outer shell formed by the air inlet end seat and the gas channel together constitute the double-wall structure, the double-wall structure makes the interior of the air inlet end seat form a hollow cavity.

[0011] Preferably, the power mechanism is an electric motor, and the working shaft of the electric motor is rotatably connected to the rotating shaft of the male or female rotor extending from the exhaust end seat. The electric motor drives the male or female rotor to rotate, and the male or female rotor can drive another rotor to rotate synchronously through transmission.

[0012] Preferably, the other end of the shaft of the male rotor extends out of the air intake seat and is fixedly connected to a first gear, and the other end of the shaft of the female rotor extends out of the air intake seat and is fixedly connected to a second gear, wherein the first gear and the second gear mesh and drive each other.

[0013] Preferably, the other end of the exhaust end seat is fixedly connected to an exhaust end cover, and the exhaust end cover is symmetrically provided with through holes, through which the shaft of the male or female rotor of the power mechanism, which extends out of the exhaust end seat, passes.

[0014] Preferably, the other end of the air intake end seat is fixedly connected to the air intake end cover, the air intake end cover is provided with two sets of symmetrical inspection ports, and the inspection ports are fitted with covers.

[0015] Preferably, the cavity inside the cylinder is of a fixed size, and the male rotor and female rotor that cooperate with the cavity inside the cylinder adopt a uniform length-to-diameter ratio, and the tooth ratio of the male rotor and female rotor is 3 to 5: 4 to 7.

[0016] Preferably, the male rotor and female rotor are variable pitch rotors, and the male rotor and female rotor mesh to form a compression chamber. The internal volume ratio of the compression chamber is adjusted by adjusting the pitch of the male rotor and female rotor. The internal volume ratio formed by the male rotor and female rotor during operation is 1.5 to 4.0.

[0017] Preferably, the first gear and the second gear are driven by helical gear meshing.

[0018] Compared with the prior art, the beneficial effects of this utility model are:

[0019] 1. The cylinder block and exhaust end seat are symmetrically arranged. The cylinder block and exhaust end seat can be rotated 180 degrees for installation. This allows for the use of a single part to meet both the working requirements of gas inlet and outlet or gas inlet and outlet, reducing the amount of spare parts required and helping to improve production efficiency.

[0020] 2. The male and female rotors adopt a uniform length-to-diameter ratio and are matched with a uniform fixed size cylinder block. The internal volume ratio is adjusted by changing the pitch of the male and female rotors, thereby improving production efficiency and product quality and reducing the amount of spare parts required for different needs. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0022] Figure 1 This is a schematic diagram of the appearance of this utility model;

[0023] Figure 2 This is a schematic diagram of the internal structure of this utility model;

[0024] Figure 3 This is a schematic diagram of the meshing of the first gear and the second gear of this utility model;

[0025] Figure 4 This is a schematic diagram of the meshing of the male rotor and female rotor of this utility model;

[0026] Figure 5 This is a schematic diagram of the meshing cross-section of the male rotor and female rotor of this utility model;

[0027] Figure 6 This is a schematic diagram of the external shape of the air intake end seat of this utility model;

[0028] Figure 7 This is a cross-sectional schematic diagram of the air intake end seat of this utility model.

[0029] Figure 8 This is a schematic diagram of the cylinder body of this utility model.

[0030] Figure 9 This is a schematic diagram of the exhaust end seat of this utility model.

[0031] Figure 10 This is a schematic diagram of the exhaust end cap of this utility model.

[0032] Figure 11 This is a schematic diagram of the air intake end cover of this utility model.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Cylinder block; 1a. First air port; 1b. Auxiliary foot; 2. Intake end seat; 2a. Bearing hole; 2b. Intake port; 2c. Through port; 2d. Gas passage; 3. Exhaust end seat; 3a. Second air port; 3b. Exhaust port; 3c. Support foot; 4. Intake end cover; 5. Exhaust end cover; 5a. Through hole; 11. Male rotor; 12. Female rotor; 12a. Compression chamber; 19. First gear; 20. Second gear. Detailed Implementation

[0035] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0036] Example 1:

[0037] like Figure 1 - Figure 11 As shown, this embodiment proposes an oil-free screw compressor, including a cylinder body 1, an intake end seat 2, an exhaust end seat 3, an intake end cover 4, an exhaust end cover 5, a male rotor 11 and a female rotor 12, wherein the male rotor 11 and the female rotor 12 are variable pitch rotors.

[0038] Specifically, one end of the cylinder block 1 is fixedly connected to the intake end seat 2, and the end of the intake end seat 2 away from the cylinder block 1 is fixedly connected to the intake end cover 4. The other end of the cylinder block 1 is fixedly connected to the exhaust end seat 3, and the end of the exhaust end seat 3 away from the cylinder block 1 is fixedly connected to the exhaust end cover 5. The male rotor 11 and the female rotor 12 are disposed inside the cylinder block 1 and form a working chamber with the intake end seat 2 and the exhaust end seat 3. The two side extension shafts of the male rotor 11 and the female rotor 12 are rotatably connected to the intake end seat 2 and the exhaust end seat 3 respectively through bearings. The male rotor 11 or the female rotor 12 is close to the exhaust end seat 3. One end of any rotating shaft can pass through the exhaust end cover 5 to form a power mechanism. The power mechanism drives the male rotor 11 or female rotor 12 to rotate. The male rotor 11 or female rotor 12 can drive another rotor to rotate synchronously through transmission. The toothed parts of the male rotor 11 and female rotor 12 located in the cylinder body 1 mesh to form a compression chamber 12a. The male rotor 11 and female rotor 12 rotate synchronously. The gas can be compressed by the compression chamber 12a. The gas enters from the intake end seat 2, is compressed by the male rotor 11 and female rotor 12 in the cylinder body 1, and is then discharged through the exhaust end seat 3.

[0039] Specifically, due to the limitations of the application scenarios of oil-free screw compressors, there are two working states for gas entry and exit: top in and top out, and top in and bottom out. That is, top in and top out means that gas enters from the top of the inlet end seat 2, is compressed, and is discharged upward from the outlet end seat 3. Top in and bottom out means that gas enters from the top of the inlet end seat 2, is compressed, and is discharged downward from the outlet end seat 3.

[0040] Furthermore, in order to better meet the working requirements of the oil-free screw compressor from top to top or from top to bottom, the cylinder block 1, intake end seat 2, exhaust end seat 3, intake end cover 4, and exhaust end seat 5 are designed in a standardized manner.

[0041] Specifically, the cylinder body 1 has a symmetrical structure, and auxiliary feet 1b are provided on the outer wall of the cylinder body 1. The auxiliary feet 1b are symmetrically distributed vertically and vertically. The auxiliary feet 1b can provide support for the cylinder body 1 after rotating 180 degrees vertically. A first air port 1a is machined on the end of the cylinder body 1 near the exhaust end seat 3, and the first air port 1a is close to one of the sets of auxiliary feet 1b. The first air port 1a can cooperate with the exhaust end seat 3.

[0042] Specifically, the intake end seat 2 is symmetrically provided with bearing holes 2a that cooperate with and pass through the male rotor 11 and female rotor 12. An intake port 2b is provided on the upper part of the intake end seat 2. An exhaust port 2c is provided on the side of the intake end seat 2 that cooperates with the cylinder body 1. The exhaust ports 2c are horizontally symmetrically distributed. A gas passage 2d is provided inside the intake end seat 2. The intake port 2b and the exhaust port 2c are connected through the gas passage 2d. The gas passage 2d cooperates with the bearing holes 2a to make the intake end seat 2 form a double-wall structure.

[0043] Specifically, the gas channel 2d surrounds the bearing hole 2a. The inner shell formed by the bearing hole 2a and the gas channel 2d, and the outer shell formed by the air intake end seat 2 and the gas channel 2d together constitute a double-wall structure. The double-wall structure makes the interior of the air intake end seat 2 form a hollow cavity.

[0044] Specifically, the exhaust end seat 3 has a second air port 3a that cooperates with the first air port 1a, and an exhaust port 3b. The second air port 3a is connected to the exhaust port 3b. The outer wall of the exhaust end seat 3 is provided with support feet 3c. The support feet 3c are symmetrically distributed vertically and are symmetrical mounting bases with fixing bolt holes to allow the exhaust end seat 3 to be rotated 180 degrees and then fixed so that the exhaust port 3b faces upward or downward.

[0045] Specifically, the intake end cover 4 is provided with two sets of symmetrical inspection ports, and the inspection ports are fitted with covers.

[0046] Specifically, the exhaust end cover 5 is provided with two sets of symmetrical through holes 5a. One end of the male rotor 11 or female rotor 12 near either of the rotating shafts of the exhaust end seat 3 can pass through the through hole 5a to form a power mechanism. The power mechanism is a motor. The working shaft of the motor is rotatably connected to the rotating shaft of the male rotor 11 or female rotor 12 extending out of the exhaust end seat 3. The motor can drive the male rotor 11 or female rotor 12 to rotate.

[0047] Specifically, the other end of the shaft of the male rotor 11 extends into the air intake end seat 2 and is fixed with a first gear 19. The other end of the shaft of the female rotor 12 extends into the air intake end seat 2 and is fixed with a second gear 20. The first gear 19 and the second gear 20 mesh to realize that when the motor drives the male rotor 11 or the female rotor 12 to rotate, the other set of rotors rotates synchronously.

[0048] Furthermore, in order to better reduce noise and achieve smooth transmission between the first gear 19 and the second gear 20, the first gear 19 and the second gear 20 adopt helical gear meshing transmission.

[0049] Specifically, motors are mature products on the market, and can be selected according to needs. There are various ways to connect motors and shafts, such as couplings or key connections, bushing connections, etc., which are all conventional connection methods in mechanical design. The appropriate connection method can be selected according to the usage scenario.

[0050] Specifically, the exhaust end cover 5 and the exhaust end seat 3 are fitted together and fixed with bolts. The hole through hole 5a without a rotating shaft is fitted with a dustproof plate.

[0051] Specifically, helical gears are a type of gear and a commonly used component in mechanical transmission. They are made of high-quality, high-strength alloy steel with surface carburizing and hardening treatment, resulting in strong load-bearing capacity. In practical applications, helical gears are characterized by smooth transmission, low impact, vibration, and noise. They are also widely used due to their advantages of small size, light weight, large torque transmission, smooth start-up, and finely graded transmission ratios.

[0052] Specifically, the tooth ratio of the male rotor 11 and the female rotor 12 is 3 to 5:4 to 7. The appropriate tooth ratio is selected according to the requirements. There are 5 common tooth ratios: 3:4, 3:5, 4:6, 5:6, and 5:7. According to the selected appropriate tooth ratio, the transmission ratio of the first gear 19 and the second gear 20 is adjusted to achieve synchronous rotation of the male rotor 11 and the female rotor 12, so that the compression chamber 12a formed by the meshing of the male rotor 11 and the female rotor 12 can smoothly compress the gas.

[0053] Specifically, during assembly, the cylinder body 1, intake end seat 2, exhaust end seat 3, intake end cover 4, and exhaust end cover 5 are fixedly connected by corresponding bolts. Before assembly, according to the working requirements of the oilless screw compressor (top inlet / top outlet or top inlet / bottom outlet), the vertical direction of the cylinder body 1 is determined. This ensures that the cylinder body 1, supported by symmetrically arranged auxiliary feet 1b, is positioned so that the first air port 1a faces upwards or downwards. Based on the direction of the first air port 1a, the direction of the exhaust end seat 3 is adjusted. Under the action of the supporting foot 3c, the second air port 3a of the exhaust end seat 3 is aligned with the first air port 1a. The intake port 1a is matched with the intake end seat 2, which is fixed at the end of the cylinder body 1 away from the first intake port 1a. Then, the corresponding intake end cover 4 and exhaust end cover 5 are fixed respectively. The male rotor 11 and female rotor 12 are placed into the cylinder body 1 at the appropriate time during assembly. The two ends of the male rotor 11 and female rotor 12 are rotatably connected to the intake end seat 2 and the exhaust end seat 3 through bearings. The first gear 19 and the second gear 20 are fixedly connected to one side of the male rotor 11 and female rotor 12 respectively. The motor is connected to any one of the shafts of the male rotor 11 and female rotor 12 on the side of the exhaust end seat 3.

[0054] Specifically, gas enters the cylinder body 1 through the gas passage 2d and the air port 2c via the gas inlet 2b of the gas inlet end seat 2. Under the action of the motor, the compression chamber 12a formed by the meshing of the male rotor 11 and the female rotor 12 compresses the gas when it rotates. After compression, the gas enters the second air port 3a through the first air port 1a and is discharged through the exhaust port 3b.

[0055] Furthermore, to better reduce changes in component dimensions and achieve standardized configuration, the cavity inside the cylinder block 1 has a fixed size. The male rotor 11 and female rotor 12, which cooperate with the cavity inside the cylinder block 1, adopt a uniform length-to-diameter ratio. The internal volume ratio formed by the male rotor 11 and female rotor 12 during operation is 1.5 to 4.0. According to the usage requirements, a suitable internal volume ratio is determined, and the internal volume ratio is adjusted by adjusting the pitch of the male rotor 11 and female rotor 12.

[0056] Specifically, the volume ratio is adjusted by adjusting the pitch of the male rotor 11 and the female rotor 12, changing the pitch design parameters of the male rotor 11 and the female rotor 12 to a design method known to relevant technicians in mechanical design.

[0057] Specifically, the variable pitch male rotor 11 and female rotor 12 also help to reduce the size of the leakage channel in the high-pressure area, which can reduce the leakage of the compressor, thereby improving the efficiency of the compressor and achieving the purpose of energy saving.

[0058] The working principle of this utility model:

[0059] S1: Adjust the pitch of the male rotor 11 and female rotor 12 according to the parameters of the internal volume ratio;

[0060] S2: Using bolts, bearings and other corresponding accessories, connect the cylinder block 1, intake end seat 2, exhaust end seat 3, intake end cover 4, exhaust end cover 5, male rotor 11 and female rotor 12 respectively, and install the first gear 19 and the second gear 20 for meshing transmission.

[0061] S3: The shaft of the male rotor 11 or female rotor 12 extending out of the exhaust end seat 3 is connected to a motor.

[0062] Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the claims and their equivalents.

Claims

1. An oil-free screw compressor, comprising a cylinder body (1), a male rotor (11), and a female rotor (12), wherein one end of the cylinder body (1) is fixedly connected to an inlet end seat (2), and the other end of the cylinder body (1) is fixedly connected to an exhaust end seat (3), wherein the male rotor (11) and the female rotor (12) are disposed within the cylinder body (1) and form a working chamber with the inlet end seat (2) and the exhaust end seat (3), characterized in that: The cylinder body (1) has a symmetrical structure. Auxiliary feet (1b) are symmetrically arranged on the outer wall of the cylinder body (1). The auxiliary feet (1b) can provide support for the cylinder body (1) after rotating 180 degrees up and down. One end of the cylinder body (1) is machined with a first air port (1a) that can cooperate with the exhaust end seat (3). The intake end seat (2) is symmetrically provided with bearing holes (2a), and an intake port (2b) is provided on the upper part of the intake end seat (2). An exhaust port (2c) is symmetrically provided on the side of the intake end seat (2) that cooperates with the cylinder body (1). The intake port (2b) and the exhaust port (2c) are connected to each other, and the intake end seat (2) forms a double-wall structure. The exhaust end seat (3) has a second air port (3a) that cooperates with the first air port (1a), and the exhaust end seat (3) has an exhaust port (3b) that communicates with the second air port (3a). Support feet (3c) are symmetrically arranged on the outer wall of the exhaust end seat (3). The exhaust end seat (3) can make the exhaust port (3b) face upward or downward with the assistance of the support feet (3c). The shaft of the male rotor (11) or female rotor (12) extending from one end of the exhaust end seat (3) forms a power mechanism.

2. The oil-free screw compressor according to claim 1, characterized in that: The double-wall structure includes a gas channel (2d), the air inlet (2b) and the air outlet (2c) are connected through the gas channel (2d), the gas channel (2d) surrounds the bearing hole (2a), the bearing hole (2a) can cooperate with the rotating shaft of the male rotor (11) and the female rotor (12), the inner shell formed by the bearing hole (2a) and the gas channel (2d) and the outer shell formed by the air inlet end seat (2) together constitute the double-wall structure, the double-wall structure makes the interior of the air inlet end seat (2) form a hollow cavity.

3. The oil-free screw compressor according to claim 1, characterized in that: The power mechanism is an electric motor. The working shaft of the electric motor is rotatably connected to the shaft of the male rotor (11) or female rotor (12) extending from the exhaust end seat (3). The electric motor drives the male rotor (11) or female rotor (12) to rotate. The male rotor (11) or female rotor (12) can drive another rotor to rotate synchronously through transmission.

4. The oil-free screw compressor according to claim 3, characterized in that: The other end of the shaft of the male rotor (11) extends out of the air intake end seat (2) and is fixedly connected to the first gear (19). The other end of the shaft of the female rotor (12) extends out of the air intake end seat (2) and is fixedly connected to the second gear (20). The first gear (19) and the second gear (20) mesh and drive each other.

5. The oil-free screw compressor according to claim 1, characterized in that: The other end of the exhaust end seat (3) is fixedly connected to the exhaust end cover (5). The exhaust end cover (5) is symmetrically provided with through holes (5a). The shaft of the male rotor (11) or female rotor (12) that extends out of the exhaust end seat (3) and is connected to the power mechanism passes through the through holes (5a).

6. The oil-free screw compressor according to claim 1, characterized in that: The other end of the air intake end seat (2) is fixedly connected to the air intake end cover (4). The air intake end cover (4) is provided with two sets of symmetrical inspection ports, and the inspection ports are fitted with covers.

7. The oil-free screw compressor according to claim 1, characterized in that: The cavity inside the cylinder body (1) has a fixed size. The male rotor (11) and female rotor (12) that cooperate with the cavity inside the cylinder body (1) adopt a uniform length-to-diameter ratio. The tooth ratio of the male rotor (11) and female rotor (12) is 3 to 5: 4 to 7.

8. The oil-free screw compressor according to claim 7, characterized in that: The male rotor (11) and female rotor (12) are variable pitch rotors. The male rotor (11) and female rotor (12) mesh to form a compression chamber (12a). The internal volume ratio of the compression chamber (12a) is adjusted by adjusting the pitch of the male rotor (11) and female rotor (12). The internal volume ratio formed by the male rotor (11) and female rotor (12) during operation is 1.5 to 4.

0.

9. The oil-free screw compressor according to claim 4, characterized in that: The first gear (19) and the second gear (20) are driven by helical gear meshing.

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