Water-cooled roots vacuum pump device

Abstract

The utility model relates to a kind of water-cooled roots vacuum pump devices, including pump body, cooling water left partition cavity is equipped between front end cover and pump body, cooling water right partition cavity is equipped between rear end cover and pump body, cooling water upper partition cavity is equipped in the top of pump body, and cooling water lower partition cavity is equipped below;The bottom of cooling water left partition cavity is equipped with two cooling water left water inlet passageways, top is equipped with two cooling water left water outlet passageways, and bottom surface is equipped with cooling water inlet;Cooling water left water inlet passageway is communicated with cooling water lower partition cavity, and cooling water left water outlet passageway is communicated with cooling water upper partition cavity;The bottom of cooling water right partition cavity is equipped with two cooling water right water inlet passageways, top is equipped with two cooling water right water outlet passageways, and top surface is equipped with cooling water outlet, cooling water right water inlet passageway is communicated with cooling water lower partition cavity, and cooling water right water outlet passageway is communicated with cooling water upper partition cavity.The utility model designs full-enclosing cooling loop, solves the problem of rotor overheating and jamming, improves temperature drop effect, and supports multi-material rotor and independent operation mode.

Description

Technical Field

[0001] This utility model relates to the field of Roots vacuum pump technology, and in particular to a water-cooled Roots vacuum pump device, which is suitable for rotor overheat protection under high compression ratio conditions. Background Technology

[0002] A Roots vacuum pump is a rotary positive displacement vacuum pump that uses two figure-eight shaped rotors rotating within a casing to generate suction and exhaust. During operation, the pumped gas is compressed inside the pump, generating significant heat. Due to the relatively small surface area of ​​the pump casing, this heat cannot dissipate quickly enough, resulting in a high internal temperature rise. Existing Roots vacuum pumps have the following drawbacks:

[0003] (1) Low heat dissipation efficiency:

[0004] Traditional Roots pumps rely on natural convection cooling of the casing, resulting in rapid temperature rise in key components of the pump chamber (rotor, end cover, and drive components). Typically, the rotor temperature is much higher than the pump casing temperature, and the thermal expansion of the rotor exceeds that of the pump casing. This reduces the gap between the rotor and the pump casing cavity, as well as the meshing gap between the rotors. Especially at high vacuum, as the pressure difference between the inlet and outlet of the Roots vacuum pump increases, more heat is generated by the compression of the gas in the pump chamber. This can cause rotor thermal expansion, leading to rotor rubbing, jamming, or stalling, and may even damage the Roots vacuum pump.

[0005] (2) Cooling limitations:

[0006] Traditional Roots vacuum pumps typically have coil coolers installed in the oil tanks at both ends. The oil tank volume is relatively small, and the heat exchange area of ​​the cooler is very limited. Therefore, the oil tank coil cooler can only cool the lubricating oil and cannot cover the core heat-generating areas such as the pump chamber / rotor. In summer or when used for a long time under high ambient temperature conditions, overheating of internal parts, rotor rubbing, and jamming are likely to occur.

[0007] (3) Poor material adaptability:

[0008] Traditional Roots vacuum pumps are mainly made of cast iron, which cannot meet the different cooling requirements of rotors made of various materials. In recent years, new Roots vacuum pumps have been made of different materials such as carbon steel, stainless steel, duplex stainless steel, Hastelloy, titanium alloy, and aluminum alloy. Due to the large differences in the coefficients of thermal expansion and thermal conductivity of these materials, the temperature rise of Roots vacuum pumps varies under the same operating conditions, and the operating conditions of Roots vacuum pumps also vary greatly.

[0009] (4) Application limitations:

[0010] Traditional Roots vacuum pumps, limited by heat dissipation, must be paired with a matching backing vacuum pump to form a vacuum unit, preventing independent operation and increasing system costs. Furthermore, traditional Roots vacuum pumps require a pre-evacuation stage by the backing pump to achieve a certain vacuum level before starting operation. The motor drives the driving rotor of the Roots vacuum pump to rotate in a specific direction via a coupling. The driving rotor, in turn, drives the driven rotor to rotate synchronously in opposite directions within the pump chamber via a synchronous gear at the shaft end. Gas pressure within the Roots vacuum pump generates heat; the higher the compression ratio, the higher the temperature rise, particularly on the exhaust side. Thermal expansion of the rotor reduces the clearance between the rotor and the pump chamber, increasing the risk of rotor rubbing against the pump chamber wall and jamming, posing significant safety hazards to the Roots vacuum pump.

[0011] Therefore, this invention proposes a water-cooled Roots vacuum pump device to solve the above problems. Summary of the Invention

[0012] The purpose of this invention is to overcome the above-mentioned shortcomings and provide a water-cooled Roots vacuum pump device, which adopts a fully enclosed water-cooling structure, has lower cost, and better cooling effect.

[0013] The purpose of this utility model is achieved as follows:

[0014] A water-cooled Roots vacuum pump device includes a Roots pump, the Roots pump including a pump body, an air inlet on the top surface of the pump body and an exhaust port on the bottom surface of the pump body; a front cover is provided at the front end of the pump body, a gear oil tank is provided on the front cover, the gear oil tank is connected to the front side of the front cover; a rear cover is provided at the rear end of the pump body, a drive end oil tank is provided on the rear end cover, the drive end oil tank is connected to the rear side of the rear cover;

[0015] A left cooling water compartment is provided between the front end cover and the pump body, a right cooling water compartment is provided between the rear end cover and the pump body, an upper cooling water compartment is provided above the pump body, and a lower cooling water compartment is provided below the pump body.

[0016] The bottom of the left cooling water compartment has two symmetrical left cooling water inlet channels, the top of the left cooling water compartment has two symmetrical left cooling water outlet channels, and the bottom surface of the left cooling water compartment has a cooling water inlet located on the bottom surface of the front end cover. The left cooling water inlet channel is connected to the lower cooling water compartment, and the left cooling water outlet channel is connected to the upper cooling water compartment.

[0017] The bottom of the right cooling water compartment has two symmetrical right cooling water inlet channels, the top of the right cooling water compartment has two symmetrical right cooling water outlet channels, and the top surface of the right cooling water compartment has a cooling water outlet, which is located on the top surface of the rear end cover; the right cooling water inlet channel is connected to the lower cooling water compartment, and the right cooling water outlet channel is connected to the upper cooling water compartment.

[0018] A cooling water inlet is provided on the end face of the pump body at the position corresponding to the left and right cooling water inlet channels, and an air-cooled outlet is provided on the end face of the pump body at the position corresponding to the left and right cooling water outlet channels.

[0019] Furthermore, the upper part of the pump body near the air inlet is an air intake chamber, and the lower part of the pump body near the exhaust port is an exhaust chamber. The air inlet is connected to the air intake chamber through an air intake connection channel, and the exhaust port is connected to the exhaust chamber through an exhaust connection channel.

[0020] Furthermore, the pump body is equipped with a pair of horizontally placed two-lobe involute synchronous rotors for pumping gas: a driving rotor and a driven rotor. The driving rotor and the driven rotor are respectively mounted on two main shafts, which are arranged in parallel between the front end cover and the rear end cover. The front end cover and the rear end cover are respectively equipped with two sets of rolling bearings for supporting the rotor main shafts and four sets of end cover dynamic seals for sealing the pump chamber and the front and rear end covers.

[0021] Furthermore, one end of the main shaft housing the active rotor extends out of the drive end oil tank and is connected to the motor via a coupling. The extended end between the main shaft housing the active rotor and the drive end oil tank is equipped with a set of mechanical seals to isolate the gas flow between the inside of the vacuum pump oil tank and the outside atmosphere, thus serving as a dynamic seal.

[0022] Furthermore, a pair of involute synchronous gears for driving the rotor to rotate synchronously in opposite directions are provided at the end of the main shaft inside the gear tank.

[0023] Furthermore, an oil level sight glass is provided on the side of the gear oil tank.

[0024] Furthermore, an oil slinger is provided at the end of the driven rotor's main shaft extending out of the drive end oil tank.

[0025] Furthermore, a motor connecting frame is provided on the outside of the drive end oil tank. The motor connecting frame enables the concentric connection between the Roots vacuum pump spindle and the motor spindle, ensuring quiet operation and low vibration of the Roots vacuum pump.

[0026] Compared with the prior art, the beneficial effects of this utility model are:

[0027] This invention provides a water-cooled Roots vacuum pump device. By setting symmetrical cooling water chambers outside the pump body's suction and exhaust chambers and connecting them with independent water chambers at the front and rear ends to form a fully enclosed cooling circuit, the pump chamber and rotor are cooled by forced convection. This invention completely solves the problem of rotor overheating and jamming, greatly improves the temperature reduction effect, supports rotors of multiple materials and independent operating modes, significantly improves reliability and reduces system costs. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of this utility model.

[0029] Figure 2 This is a top sectional view of the present invention.

[0030] Figure 3 This is a side sectional view of the present invention.

[0031] Figure 4 This is a schematic diagram of the cooling water flow direction of this utility model.

[0032] Figure 5 This is a schematic diagram of the process of the air-cooled external circulating water cooling device of this utility model.

[0033] in:

[0034] Roots pump 1, Pump body 1.1, Air inlet 1.2, Exhaust outlet 1.3, Suction chamber 1.4, Exhaust chamber 1.5, Front end cover 2, Rear end cover 3, Gear oil tank 4, Synchronous gear 4.1, Oil level sight glass 4.2, Drive end oil tank 5, Oil slinger 5.1, Driving rotor 6, Driven rotor 7, Left cooling water compartment 8, Left cooling water inlet channel 8.1, Left cooling water outlet channel 8.2, Cooling water inlet 8.3, Right cooling water compartment 9, Right cooling water inlet channel 9.1, Right cooling water outlet channel 9.2, Cooling water outlet 9.3, Upper cooling water compartment 10, Lower cooling water compartment 11, Rolling bearing 12, End cover dynamic seal 13, Mechanical seal 14, Coupling 15, Motor 16, Motor connecting frame 17. Detailed Implementation

[0035] To better understand the technical solution of this utility model, a detailed description will be provided below in conjunction with relevant illustrations. It should be understood that the specific embodiments described below are not intended to limit the specific implementation of the technical solution of this utility model, but are merely possible implementations of the technical solution of this utility model. It should be noted that the descriptions of the positional relationships of the components herein, such as component A being located above component B, are based on the relative positions of the components in the illustrations and are not intended to limit the actual positional relationships of the components. Example

[0036] See Figures 1-4 , Figure 1A schematic diagram of the structure of this utility model has been drawn. As shown in the figure, a water-cooled Roots vacuum pump device includes a Roots pump 1, which includes a pump body 1.1. The top surface of the pump body 1.1 is provided with an air inlet 1.2, and the bottom surface of the pump body 1.1 is provided with an exhaust port 1.3. The upper part of the pump body 1.1 near the air inlet 1.2 is a suction chamber 1.4, and the lower part of the pump body 1.1 near the exhaust port 1.3 is an exhaust chamber 1.5. The air inlet 1.2 is connected to the suction chamber 1.4 through a suction connection channel, and the exhaust port 1.3 is connected to the exhaust chamber 1.5 through an exhaust connection channel.

[0037] The pump body 1.1 has a front cover 2 at its front end, and a gear oil tank 4 is provided on the front cover 2. The gear oil tank 4 is fixedly connected to the front side of the front cover 2 with hexagon socket screws. The pump body 1.1 has a rear cover 3 at its rear end, and a drive end oil tank 5 is provided on the rear cover 3. The drive end oil tank 5 is fixedly connected to the rear side of the rear cover 3 with hexagon socket screws.

[0038] A cooling water left partition 8 is provided between the front end cover 2 and the pump body 1.1, a cooling water right partition 9 is provided between the rear end cover 3 and the pump body 1.1, an upper cooling water partition 10 is provided above the pump body 1.1, and a lower cooling water partition 11 is provided below the pump body 1.1.

[0039] The bottom of the left cooling water diaphragm 8 is provided with two symmetrical left cooling water inlet channels 8.1, the top of the left cooling water diaphragm 8 is provided with two symmetrical left cooling water outlet channels 8.2, and the bottom surface of the left cooling water diaphragm 8 is provided with a cooling water inlet 8.3, which is located on the bottom surface of the front end cover 2; the left cooling water inlet channel 8.1 is connected to the lower cooling water diaphragm 11, and the left cooling water outlet channel 8.2 is connected to the upper cooling water diaphragm 10.

[0040] The bottom of the right cooling water diaphragm 9 is provided with two symmetrical right cooling water inlet channels 9.1, the top of the right cooling water diaphragm 9 is provided with two symmetrical right cooling water outlet channels 9.2, and the top surface of the right cooling water diaphragm 9 is provided with a cooling water outlet 9.3, which is located on the top surface of the rear end cover 3; the right cooling water inlet channel 9.1 is connected to the lower cooling water diaphragm 11, and the right cooling water outlet channel 9.2 is connected to the upper cooling water diaphragm 10.

[0041] Cooling water inlet ports are provided on the end face of the pump body 1.1 at the positions corresponding to the left cooling water inlet channel 8.1 and the right cooling water inlet channel 9.1. Air-cooled outlet ports are provided on the end face of the pump body 1.1 at the positions corresponding to the left cooling water outlet channel 8.2 and the right cooling water outlet channel 9.2.

[0042] Thus, the left cooling water compartment 8, the right cooling water compartment 9, the upper cooling water compartment 10, and the lower cooling water compartment 11 are interconnected through the cooling water channel, forming an internal circulating closed loop of cooling water, thus forming a fully enclosed water cooling structure.

[0043] See Figure 4 In this embodiment, the flow direction of the cooling water is as follows: cooling water inlet 8.3 → cooling water left diaphragm 8 → cooling water left inlet channel 8.1 → cooling water lower diaphragm 11 → cooling water right inlet channel 9.1 → cooling water right diaphragm 9 → cooling water outlet 9.3 or cooling water right outlet channel 9.2 → cooling water upper diaphragm 10 → cooling water left outlet channel 8.2 → cooling water left diaphragm 8, forming a circulation.

[0044] The pump body 1.1 is equipped with a pair of horizontally placed two-lobe involute synchronous rotors for pumping gas: a driving rotor 6 and a driven rotor 7. The driving rotor 6 and the driven rotor 7 are respectively sleeved on two main shafts. The two main shafts are arranged in parallel between the front end cover 2 and the rear end cover 3. The front end cover 2 and the rear end cover 3 are respectively provided with two sets of rolling bearings 12 for supporting the rotor main shafts and four sets of end cover dynamic seals 13 for sealing the pump chamber and the front and rear end covers.

[0045] One end of the main shaft with the active rotor 6 extends out of the drive end oil tank 5 and is connected to the motor 16 via a coupling 15. A set of mechanical seals 14 is provided at the extended end between the main shaft with the active rotor 6 and the drive end oil tank 5 to isolate the gas flow between the inside of the vacuum pump oil tank and the outside atmosphere, thus playing a dynamic sealing role.

[0046] The gear oil tank 4 is equipped with a pair of involute synchronous gears 4.1 at the end of the main shaft for driving the rotor to rotate synchronously in opposite directions. The gear oil tank 4 is equipped with an oil level sight glass 4.2 on its side.

[0047] An oil slinger 5.1 is provided at the end of the oil tank 5 extending from the main shaft of the driven rotor 7;

[0048] The outer side of the drive end oil tank 5 is provided with a motor connecting frame 17, which realizes the concentric connection between the main shaft of the Roots vacuum pump and the main shaft of the motor 16, ensuring the quiet operation and low vibration of the Roots vacuum pump.

[0049] When the Roots vacuum pump is working, the left rotor rotates counterclockwise and the right rotor rotates clockwise. The two rotors are driven by a pair of synchronous gears in the gearbox to rotate in opposite directions at the same speed in the pump chamber to achieve the functions of suction, compression and exhaust.

[0050] The high-temperature gas discharged by the Roots vacuum pump is cooled in time by the cooling water in the cooling water chambers around the pump casing and the front and rear end covers. This effectively controls the temperature rise of the rotor and the inner wall of the pump chamber, ensuring that the gap between the rotor and the inner wall of the pump chamber and the meshing gap between the two rotors remain unchanged.

[0051] Depending on the process requirements, the Roots vacuum pump can also be equipped with a fully automatic external cooling water circulation system, which provides good cooling water effect, energy saving, water conservation, and convenient operation. (See also...) Figure 5 This embodiment of a water-cooled Roots vacuum pump device includes a fully automatic external cooling water circulation system. The Roots vacuum pump is connected to a PLC computer control box via an inlet main valve. The Roots vacuum pump is connected to a pressure transmitter, which is also connected to the PLC computer control box. The cooling water inlet of the Roots vacuum pump is connected to an air condenser, which is connected to a pipeline pump. The pipeline pump is connected to a filter, which is connected to a water tank. The water tank is equipped with an intelligent level gauge. The cooling water return port of the water tank is connected to the Roots vacuum pump, and the intelligent level gauge is connected to the PLC computer control box. The water tank is connected to the PLC computer control box via a water replenishment solenoid valve. The water tank is also connected to the water tank drain port via a drain valve.

[0052] Specific implementation case: Taking a titanium alloy rotor Roots pump under a 10kPa differential pressure condition as an example:

[0053] (1) Cooling system configuration:

[0054] Cooling water flow rate: 10L / min, inlet water temperature: 25℃;

[0055] External circulation device power: 1.5kW.

[0056] (2) Operation results:

[0057] Rotor temperature: decreased from 210℃ to 85℃ (a decrease of 60%).

[0058] Rotor-pump chamber clearance: stable at 0.15±0.03mm (design value 0.15mm);

[0059] Independent operation vacuum level: up to 1×10⁻² Pa (no backing pump required).

[0060] (3) Sealing performance:

[0061] The lip seal (fluororubber) ensures an oil contamination rate of <0.1ppm, meeting the requirements for oil-free operation.

[0062] The comparison between this embodiment and a traditional Roots pump is shown in the table below:

[0063]

[0064] Working principle:

[0065] This utility model discloses a water-cooled Roots vacuum pump device, comprising:

[0066] (1) Fully enclosed water cooling system:

[0067] 1.1 Pump body cooling chamber: Left and right cooling water chambers are symmetrically arranged outside the suction and exhaust chambers, forming a closed loop through the end face channel;

[0068] 1.2 End cover cooling chamber: Independent water chambers are provided around the front and rear end covers, which are connected to the pump body chamber through interfaces;

[0069] (2) Upgrade of dual-stage dynamic seal:

[0070] The end cap dynamic seal adopts a labyrinth seal + lip seal composite structure to isolate oil and improve sealing reliability.

[0071] (3) Modular connection design:

[0072] The cooling water interface is standardized (DN25), supporting quick connection of external circulation devices.

[0073] This invention relates to a water-cooled Roots vacuum pump device, which features a simple structure, low manufacturing cost, and improved cooling effect. The purpose of this invention is to compensate for and upgrade the insufficient heat dissipation and cooling of traditional Roots vacuum pumps. Furthermore, the dynamic sealing structure of the end cap has been upgraded by adding a lip seal to the traditional labyrinth seal, further improving the reliability of the dynamic seal and achieving oil-free and contamination-free suction chamber, making it suitable for more special working conditions. With the improved cooling structure, the novel Roots vacuum pump can further expand its application range; it can be used in conjunction with a backing vacuum pump to form a vacuum unit, or it can be used independently with an external cooling water circulation device.

[0074] This invention utilizes a fully enclosed cooling water chamber located around the pump body and the front and rear end covers. This chamber completely surrounds the main heat-generating components of the Roots vacuum pump, rapidly cooling the internal parts. The overall structure is simple, has good cooling effect, and is inexpensive. It also effectively solves the problems of high temperature rise, overheating, and easy jamming of Roots vacuum pumps during high vacuum operation.

[0075] The above are merely specific application examples of this utility model and do not constitute any limitation on the scope of protection of this utility model. All technical solutions formed by equivalent transformations or equivalent substitutions fall within the scope of protection of this utility model.

Claims

1. A water-cooled Roots vacuum pump device, characterized in that: It includes a Roots pump (1), the Roots pump (1) includes a pump body (1.1), the top surface of the pump body (1.1) is provided with an air inlet (1.2), and the bottom surface of the pump body (1.1) is provided with an exhaust port (1.3); the front end of the pump body (1.1) is provided with a front end cover (2), the front end cover (2) is provided with a gear oil tank (4), the gear oil tank (4) is connected to the front side of the front end cover (2); the rear end of the pump body (1.1) is provided with a rear end cover (3), the rear end cover (3) is provided with a drive end oil tank (5), the drive end oil tank (5) is connected to the rear side of the rear end cover (3); A cooling water left diaphragm (8) is provided between the front end cover (2) and the pump body (1.1), a cooling water right diaphragm (9) is provided between the rear end cover (3) and the pump body (1.1), a cooling water upper diaphragm (10) is provided above the pump body (1.1), and a cooling water lower diaphragm (11) is provided below the pump body (1.1). The bottom of the left cooling water diaphragm (8) is provided with two symmetrical left cooling water inlet channels (8.1), the top of the left cooling water diaphragm (8) is provided with two symmetrical left cooling water outlet channels (8.2), and the bottom surface of the left cooling water diaphragm (8) is provided with a cooling water inlet (8.3), which is located on the bottom surface of the front end cover (2); the left cooling water inlet channel (8.1) is connected to the lower cooling water diaphragm (11), and the left cooling water outlet channel (8.2) is connected to the upper cooling water diaphragm (10); The bottom of the right cooling water diaphragm (9) is provided with two symmetrical right cooling water inlet channels (9.1), the top of the right cooling water diaphragm (9) is provided with two symmetrical right cooling water outlet channels (9.2), the top surface of the right cooling water diaphragm (9) is provided with a cooling water outlet (9.3), and the cooling water outlet (9.3) is located on the top surface of the rear end cover (3); the right cooling water inlet channel (9.1) is connected to the lower cooling water diaphragm (11), and the right cooling water outlet channel (9.2) is connected to the upper cooling water diaphragm (10); A cooling water inlet is provided on the end face of the pump body (1.1) at the position corresponding to the left cooling water inlet channel (8.1) and the right cooling water inlet channel (9.1). An air-cooled outlet is provided on the end face of the pump body (1.1) at the position corresponding to the left cooling water outlet channel (8.2) and the right cooling water outlet channel (9.2).

2. The water-cooled Roots vacuum pump device according to claim 1, characterized in that: The upper part of the pump body (1.1) near the air inlet (1.2) is the air intake chamber (1.4), and the lower part of the pump body (1.1) near the exhaust port (1.3) is the exhaust chamber (1.5). The air inlet (1.2) is connected to the air intake chamber (1.4) through the air intake connection channel, and the exhaust port (1.3) is connected to the exhaust chamber (1.5) through the exhaust connection channel.

3. The water-cooled Roots vacuum pump device according to claim 1, characterized in that: The pump body (1.1) is equipped with a pair of horizontally placed two-lobe involute synchronous rotors for pumping gas: an active rotor (6) and a driven rotor (7). The active rotor (6) and the driven rotor (7) are respectively mounted on two main shafts. The two main shafts are arranged in parallel between the front end cover (2) and the rear end cover (3). The front end cover (2) and the rear end cover (3) are respectively equipped with two sets of rolling bearings (12) for supporting the rotor main shafts and four sets of end cover dynamic seals (13) for sealing the pump chamber and the front and rear end covers.

4. The water-cooled Roots vacuum pump device according to claim 3, characterized in that: One end of the main shaft with the active rotor (6) extends out of the drive end oil tank (5) and is connected to the motor (16) through the coupling (15). The extended end between the main shaft with the active rotor (6) and the drive end oil tank (5) is provided with a set of mechanical seals (14) to isolate the gas flow between the inside of the vacuum pump oil tank and the outside atmosphere, and to play a dynamic sealing role.

5. A water-cooled Roots vacuum pump device according to claim 1, characterized in that: The main shaft inside the gear oil tank (4) is equipped with a pair of involute synchronous gears (4.1) for driving the rotor to rotate synchronously in opposite directions.

6. The water-cooled Roots vacuum pump device according to claim 1, characterized in that: The gear oil tank (4) is provided with an oil level sight glass (4.2) on its side.

7. A water-cooled Roots vacuum pump device according to claim 1, characterized in that: An oil slinger (5.1) is provided at the end of the main shaft of the driven rotor (7) extending out of the drive end oil tank (5).

8. A water-cooled Roots vacuum pump device according to claim 1, characterized in that: The drive end oil tank (5) is provided with a motor connecting frame (17) on the outside. The motor connecting frame (17) enables the concentric connection between the main shaft of the Roots vacuum pump and the main shaft of the motor (16), ensuring the quiet operation and low vibration of the Roots vacuum pump.

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