Double-motor screw vacuum pump with built-in rotor for cooling and rotor cooling method

Abstract

The invention relates to a double-motor screw vacuum pump with a built-in rotor for cooling and a rotor cooling method. The motor comprises a motor shell, a gear box, a pump shell and a front end cover, one end of the motor shell is fixed to one end of the gear box, the other end of the gear box is fixed to one end of the pump shell, and the front end cover is fixed to the other end of the pump shell. Each rotor mechanism comprises a rotor assembly, a motor and a protective gear, one end of the rotor assembly is installed at the other end of the motor shell, the middle of the rotor assembly is installed at the other end of the gear box, the front half portion of the rotor assembly is of a cantilever type structure and located in the pump shell, and the motor is installed on the rotor assembly and located in the motor shell; the protection gear is installed on the rotor assembly and located in the gear box, and a cooling liquid channel is formed in the rotor mechanism; the two rotor mechanisms are installed side by side. The motor is good in heat dissipation effect, facilitates the maintenance of the rotor, and is small in size.

Description

Technical Field

[0001] The present invention relates to a screw vacuum pump, in particular to a dual-motor screw vacuum pump with built-in rotor cooling and a rotor cooling method, which can be applied in the fields of photovoltaics, semiconductors, chemical industry, etc. Background Art

[0002] Screw vacuum pumps are usually dry pumps. There is no coolant in the exhaust chamber of the screw vacuum pump, so the heat generated by the gas during compression and transportation is difficult to dissipate. It is necessary to solve the heat dissipation problem of the screw vacuum pump. At present, the commonly used cooling methods are divided into air cooling and water cooling. The air cooling method is achieved by adding heat dissipation fins and external fans to the casing of the screw vacuum pump; the water cooling method is to add a cooling jacket to the casing of the screw vacuum pump, and the coolant flows in the cooling jacket to cool the screw vacuum pump. Both cooling methods have a common disadvantage, that is, they are cooled from the outside to the inside of the screw vacuum pump, and it is difficult to effectively cool the entire rotor. Only the casing and the outer circle of the rotor of the screw vacuum pump can be cooled, and the high-temperature heat dissipation effect at the root of the rotor is not ideal. Under some working conditions, the high temperature at the root of the rotor will be transmitted to the seals and bearings on both sides of the rotor through the rotor shaft. These parts will affect their service life under the action of high temperature, and then affect the overall performance of the screw vacuum pump.

[0003] At the same time, during the actual use of the screw vacuum pump, the pumped process gas usually produces dust, colloid and other impurities in the pump, and the gap between the rotor and the housing is relatively small during normal use of the screw vacuum pump. The accumulation of these dust and other impurities may cause the machine to jam and affect the normal use of the vacuum pump. Therefore, the maintenance of the vacuum pump is mainly to clean the rotor and clean up the dust and other impurities accumulated on the rotor. However, when performing maintenance on the commonly used screw vacuum pumps, it is usually necessary to completely disassemble the entire screw vacuum pump to clean up the impurities accumulated on the rotor. This is usually difficult to operate at the process site where the screw vacuum pump is used, which also causes the problem of difficult maintenance. The essence of this problem is that the support bearings of the internal rotor of the currently commonly used screw vacuum pumps are distributed at both ends of the rotor. Therefore, the rotor can only be separated from the casing after the bearings at both ends of the rotor are removed, which is almost equivalent to completely disassembling the entire screw vacuum pump. This places high demands on the disassembly and assembly tools and operators, and the workload of disassembling and assembling the screw vacuum pump is also large, which brings great inconvenience to the maintenance of the screw vacuum pump.

[0004] In addition, in actual working environments, dry screw vacuum pumps usually require several screw vacuum pumps to be used simultaneously. From the perspective of customer use, it is very necessary to reduce the size and power of a single screw vacuum pump. As for the solution to reduce the size of screw vacuum pumps, the commonly used solution is to increase the speed of the screw vacuum pump and replace the larger pump with a small pump to increase the speed and pumping speed, thereby reducing the size. However, for the sake of stability and safety, this solution requires increasing the power of the motor and needs to be equipped with a large motor. When a small pump is equipped with a large motor, since the size of the pump itself is already relatively compact, the size of the conventional asynchronous motor is too large compared to the size of the pump. Instead, the size of the motor has become an important factor in measuring the size of the entire screw vacuum pump. Summary of the invention

[0005] The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art and to provide a dual-motor screw vacuum pump and a rotor cooling method which have reasonable structural design, good heat dissipation effect, convenient rotor maintenance, small size, and built-in rotor cooling.

[0006] The technical solution adopted by the present invention to solve the above-mentioned problem is: the dual-motor screw vacuum pump with built-in rotor cooling comprises a motor housing, a gear box, a pump housing and a front end cover, one end of the motor housing is fixed to one end of the gear box, the other end of the gear box is fixed to one end of the pump housing, a gear box cavity is arranged in the gear box, and the front end cover is fixed to the other end of the pump housing. Its structural characteristics are: it also comprises two sets of rotor mechanisms, each set of rotor mechanisms comprises a rotor assembly, a motor and a protective gear, one end of the rotor assembly is mounted on the other end of the motor housing, the middle part of the rotor assembly is mounted on the other end of the gear box, the front half of the rotor assembly is a cantilever structure and is located in the pump housing, the motor is mounted on the rotor assembly, the motor is located in the motor housing, the protective gear is mounted on the rotor assembly, the protective gear is located in the gear box cavity of the gear box, and a coolant channel is arranged inside the rotor mechanism; the two sets of rotor mechanisms are mounted side by side, the teeth of one protective gear in the two sets of rotor mechanisms are embedded in the tooth groove of the other protective gear, but the two protective gears in the two sets of rotor mechanisms do not contact each other.

[0007] Preferably, the rotor assembly of the present invention comprises a rotor shaft, a shaft sleeve, a shaft sleeve and a rotor, the front half of the rotor shaft is sleeved in the rear half of the rotor, and a shaft sleeve mounting cavity is formed between the front end of the rotor shaft and the front end of the rotor, the shaft sleeve is fixed to the front end of the rotor shaft, and the shaft sleeve is located in the shaft sleeve mounting cavity; the shaft sleeve is sleeved in the rotor shaft and is located in the front half of the rotor shaft; the motor and the protective gear are both directly mounted on the rotor shaft; the two rotors in the two sets of rotor mechanisms cooperate with each other.

[0008] Preferably, the motor housing of the present invention includes a No. 1 bearing and a bearing seat, the bearing seat is fixed at the other end of the motor housing, and the rear end of the rotor shaft is mounted on the bearing seat through the No. 1 bearing; the gear box includes a No. 2 bearing, and a bearing hole is provided at the other end of the gear box, the No. 2 bearing is mounted in the bearing hole, and the middle part of the rotor shaft is mounted on the No. 2 bearing.

[0009] Preferably, the rotor shaft of the present invention is a hollow structure, in which a rotor shaft cooling channel is arranged; the shaft sleeve is a hollow structure, in which a shaft sleeve cooling channel is arranged, and the head of the shaft sleeve cooling channel is connected to the tail of the rotor shaft cooling channel; a shaft sleeve cavity is arranged in the shaft sleeve, and the head of the shaft sleeve cavity is connected to the tail of the shaft sleeve cooling channel; the rotor is a hollow structure, and a cover is arranged at the front end of the rotor.

[0010] Preferably, a coolant input hole is provided in the bearing seat of the present invention, and the coolant input hole is communicated with the head of the rotor shaft cooling channel in the rotor shaft.

[0011] Preferably, a rotor front cooling chamber is formed between the outer wall of the shaft sleeve and the inner wall of the rotor, a rotor rear cooling chamber is formed between the outer wall of the front of the rotor shaft and the inner wall of the rotor, and a coolant reflux chamber is formed between the outer wall of the rear half of the shaft sleeve tube and the inner wall of the rotor shaft.

[0012] Preferably, the tail of the shaft sleeve of the present invention is provided with a shaft sleeve hole, and the tail of the shaft sleeve cavity and the head of the rotor front cooling cavity are connected through the shaft sleeve hole; the front end of the rotor shaft is provided with a horizontal rotor shaft coolant inlet hole, and the tail of the rotor front cooling cavity and the head of the rotor rear cooling cavity are connected through the rotor shaft coolant inlet hole; the rotor shaft is provided with a rotor shaft radial through hole, and the tail of the rotor rear cooling cavity and the head of the coolant reflux cavity are connected through the rotor shaft radial through hole; the rotor shaft is provided with a rotor shaft coolant reflux hole, and the protective gear is provided with a gear coolant reflux hole, the gear coolant reflux hole and the rotor shaft coolant reflux hole are aligned, and the tail of the coolant reflux cavity passes through the rotor shaft coolant reflux hole and the gear coolant reflux hole in turn and is connected to the gear box cavity in the gear box; the bottom of the gear box is provided with a coolant output hole.

[0013] Preferably, the rotor front cooling cavity, rotor rear cooling cavity and coolant reflux cavity described in the present invention are all annular structures; the number of sleeve holes on the sleeve is 4 to 8, the number of rotor shaft coolant inlet holes, the number of rotor shaft radial through holes and the number of rotor shaft coolant reflux holes on the rotor shaft are all 4 to 8, and the number of gear coolant reflux holes on the protective gear is equal to the number of rotor shaft coolant reflux holes.

[0014] Preferably, the rotor of the present invention is made of aluminum, magnesium-aluminum alloy or titanium alloy, and the pump housing is made of aluminum, magnesium-aluminum alloy or titanium alloy.

[0015] Preferably, the protective gear of the present invention is fixed on the rotor shaft by a key.

[0016] A rotor cooling method for a dual-motor screw vacuum pump with built-in rotor cooling is characterized in that: the coolant used for cooling enters through the coolant input hole, passes through the rotor shaft cooling channel, the shaft sleeve cooling channel, the shaft sleeve cavity, the shaft sleeve hole, the rotor front cooling cavity, the rotor shaft coolant inlet hole, the rotor rear cooling cavity, the rotor shaft radial through hole, the coolant reflux cavity and the coolant channel composed of the rotor shaft coolant reflux hole, then enters the gear box cavity of the gear box through the gear coolant reflux hole, and flows out from the coolant output hole of the gear box, thereby completing the cooling of the entire rotor assembly.

[0017] Compared with the prior art, the present invention has the following advantages and effects: the present invention improves the stability of the use of the screw vacuum pump, reduces the overall volume of the pump, and reduces the difficulty of maintenance of the screw vacuum pump.

[0018] In order to solve the problem that the coolant in the screw vacuum pump is difficult to cool to the root of the rotor, the present invention provides a solution for cooling by opening a hole in the rotor shaft and installing a shaft sleeve and a sleeve to guide the flow of the coolant. By connecting an oil pump (such as a centrifugal pump, gear pump, etc.) to the coolant input hole at the end of the rotor shaft, the coolant is pumped into the rotor shaft, and then the flow is drained through the shaft sleeve and sleeve inside the rotor to achieve the purpose of cooling the rotor from the rotor axis. Compared with the existing cooling method of using an external fan or cooling jacket, this cooling method of the present invention directly cools the rotor from the inside out, and the cooling effect is more significant.

[0019] In order to solve the problem of difficult maintenance and disassembly in the screw vacuum pump, the present invention sets the bearing supporting the rotor to one end and the middle of the rotor shaft, so that the rotor becomes a cantilever structure. Since there is no direct contact between the bearing and the pump housing, the pump housing is only fixed on the gear box, so that the pump housing does not need to remove the bearing when disassembling, which is convenient for disassembly. After the pump housing is removed, the rotor is exposed to the outside, and the rotor can be cleaned, making it very convenient to disassemble and assemble the rotor when maintenance is required. The biggest advantage of this solution in the present invention is that there are fewer parts to disassemble, and the sealing parts and bearings are not affected during disassembly, and the clearance value of the rotor is not affected. After maintenance, the pump housing can be directly installed and can continue to be used. At the same time, in order to improve the stability of the cantilever structure and reduce the difficulty of disassembly, the materials of the cantilever rotor and pump housing are preferably not made of conventional steel materials, and it is best to make adjustments, such as using metal materials with lower density such as aluminum.

[0020] In order to reduce the size and power of the screw vacuum pump, the present invention provides a dual-motor drive solution, which uses two motors to drive two rotor shafts respectively, and the power demand of a single motor is halved. At the same time, both motors are installed in a direct connection form, that is, the rotor of the motor is directly sleeved on the rotor shaft of the screw vacuum pump. Taking a 15kW motor as an example, the 7.5kW motor is much smaller than a single 15kW motor in terms of casing diameter and length. Therefore, installing two 7.5kW motors on two rotor shafts respectively can not only shorten the total length of the screw vacuum pump, but also reduce the height. At the same time, the space in front of the originally vacant rotor mechanism is utilized, and the width of the screw vacuum pump is not increased. The overall size is more compact than a single 15kW motor. At the same time, the original single-motor screw vacuum pump still needs gears or belts for transmission between the main rotor and the slave rotor. The dual-motor solution is directly driven independently by the motor, eliminating a transmission structure, and further improving energy efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention and / or the technical solutions in the prior art, the drawings required for use in the embodiments and / or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a schematic diagram of the main structure of a dual-motor screw vacuum pump with built-in rotor cooling in an embodiment of the present invention.

[0023] Figure 2 It is a schematic diagram of the internal structure of a dual-motor screw vacuum pump with built-in rotor cooling in an embodiment of the present invention.

[0024] Figure 3 yes Figure 2 Schematic diagram of the structure after enlargement at A in the middle.

[0025] Figure 4 yes Figure 2 Schematic diagram of the enlarged structure at point B.

[0026] Figure 5 yes Figure 2 Schematic diagram of the enlarged structure at point C in the middle.

[0027] Figure 6 yes Figure 2 Schematic diagram of the enlarged structure at D in the middle.

[0028] In the figure: 1-motor housing; 2-gear box; 3-pump housing; 4-front end cover; 5-rotor mechanism; 11-bearing No. 1; 12-bearing seat; 13-coolant input hole; 14-motor; 21-bearing hole; 22-bearing No. 2; 23-gear box cavity; 24-protective gear; 25-key; 51-rotor shaft; 52-shaft sleeve; 53-shaft sleeve; 54-rotor; 55-rotor shaft cooling channel; 56-shaft sleeve cooling channel; 57-shaft sleeve cavity; 58-shaft sleeve installation cavity; 59-cover; 61-shaft sleeve hole; 62-rotor shaft coolant inlet hole; 63-rotor shaft radial through hole; 64-rotor shaft coolant reflux hole; 65-gear coolant reflux hole; 71-rotor front cooling cavity; 72-rotor rear cooling cavity; 73-coolant reflux cavity. DETAILED DESCRIPTION

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and by way of examples. The following examples are intended to explain the present invention but the present invention is not limited to the following examples.

[0030] Example

[0031] See also Figures 1 to 6 The dual-motor screw vacuum pump with built-in rotor cooling in this embodiment includes a motor housing 1, a gear box 2, a pump housing 3, a front end cover 4 and two sets of rotor mechanisms 5.

[0032] In this embodiment, one end of the motor housing 1 is fixed to one end of the gear box 2, the other end of the gear box 2 is fixed to one end of the pump housing 3, a gear box cavity 23 is provided in the gear box 2, and the front end cover 4 is fixed to the other end of the pump housing 3. The pump housing 3 and the gear box 2 are directly fixed, so that when the pump housing 3 and the front end cover 4 are directly disassembled, the assembly requirements inside the dual-motor screw vacuum pump will not be affected.

[0033] Each rotor mechanism 5 in this embodiment includes a rotor assembly, a motor 14 and a protective gear 24. One end of the rotor assembly is installed at the other end of the motor housing 1, and the middle part of the rotor assembly is installed at the other end of the gear box 2. The front half of the rotor assembly is a cantilever structure and is located in the pump housing 3. The motor 14 is installed on the rotor assembly, and the motor 14 is located in the motor housing 1. The protective gear 24 is installed on the rotor assembly, and the protective gear 24 is located in the gear box cavity 23 of the gear box 2. A coolant channel is provided inside the rotor mechanism 5; two sets of rotor mechanisms 5 are installed side by side, and the teeth of one protective gear 24 in the two sets of rotor mechanisms 5 are embedded in the tooth grooves of the other protective gear 24, but the two protective gears 24 in the two sets of rotor mechanisms 5 do not contact each other.

[0034] The rotor assembly in this embodiment includes a rotor shaft 51, a shaft sleeve 52, a shaft sleeve 53 and a rotor 54. The front half of the rotor shaft 51 is sleeved in the rear half of the rotor 54, and a shaft sleeve installation cavity 58 is formed between the front end of the rotor shaft 51 and the front end of the rotor 54. The shaft sleeve 53 is fixed to the front end of the rotor shaft 51, and the shaft sleeve 53 is located in the shaft sleeve installation cavity 58; the shaft sleeve 52 is sleeved in the rotor shaft 51 and is located in the front half of the rotor shaft 51; the motor 14 and the protective gear 24 are directly mounted on the rotor shaft 51, and the protective gear 24 is usually fixed to the rotor shaft 51 by a key 25. The two rotors 54 in the two sets of rotor mechanisms 5 match but do not contact, that is, the teeth on the two rotors 54 match but do not contact. When the two rotors 54 are driven to rotate by the motor 14 connected thereto, the two rotors 54 can compress and transport the working fluid. The material of the rotor 54 is preferably aluminum, magnesium-aluminum alloy or titanium alloy, and the material of the pump housing 3 is preferably aluminum, magnesium-aluminum alloy or titanium alloy. The two rotor shafts 51 in the two sets of rotor mechanisms 5 are each driven by an independent motor 14, that is, one motor 14 in one set of rotor mechanisms 5 drives one rotor shaft 51, and one motor 14 in the other set of rotor mechanisms 5 drives one rotor shaft 51. The two rotor shafts 51 are driven independently, which is conducive to reducing the power required by the motor 14. The power of the motor 14 is half of the power of the existing conventional motor of the corresponding pumping speed vacuum pump. The dual-motor solution is significantly smaller than the single-motor solution in size, which is very beneficial to reducing the overall volume of the screw vacuum pump. Since the rotor shafts 51 are independently driven by the motor 14, the two protective gears 24 in the two sets of rotor mechanisms 5 do not contact or mesh with each other, and only play a protective role.

[0035] The motor housing 1 in this embodiment includes a No. 1 bearing 11 and a bearing seat 12, the bearing seat 12 is fixed to the other end of the motor housing 1, and the rear end of the rotor shaft 51 is mounted on the bearing seat 12 through the No. 1 bearing 11; the gear box 2 includes a No. 2 bearing 22, the other end of the gear box 2 is provided with a bearing hole 21, the No. 2 bearing 22 is mounted in the bearing hole 21, and the middle part of the rotor shaft 51 is mounted on the No. 2 bearing 22. It can be seen that the rotor 54 forms a cantilever structure, and the No. 1 bearing 11 and the No. 2 bearing 22 are not in contact with the pump housing 3. When disassembling the pump housing 3, the pump housing 3 can be disassembled without disassembling the No. 1 bearing 11 and the No. 2 bearing 22. The disassembly of the pump housing 3 is very convenient, and it is convenient to clean the rotor 54 and perform other maintenance.

[0036] The rotor shaft 51 in this embodiment is a hollow structure, and a rotor shaft cooling channel 55 is provided in the rotor shaft 51; a coolant input hole 13 is provided in the bearing seat 12, and the coolant input hole 13 is a coolant inlet of an external drive pump, and the coolant input hole 13 is connected to the head of the rotor shaft cooling channel 55 in the rotor shaft 51. The shaft sleeve 52 is a hollow structure, and a shaft sleeve cooling channel 56 is provided in the shaft sleeve 52, and the head of the shaft sleeve cooling channel 56 is connected to the tail of the rotor shaft cooling channel 55; a shaft sleeve cavity 57 is provided in the shaft sleeve 53, and the head of the shaft sleeve cavity 57 is connected to the tail of the shaft sleeve cooling channel 56; the rotor 54 is a hollow structure, and a cover 59 is provided at the front end of the rotor 54.

[0037] In this embodiment, a rotor front cooling chamber 71 is formed between the outer wall of the sleeve 53 and the inner wall of the rotor 54, a rotor rear cooling chamber 72 is formed between the outer wall of the front of the rotor shaft 51 and the inner wall of the rotor 54, and a coolant reflux chamber 73 is formed between the outer wall of the rear half of the sleeve tube 52 and the inner wall of the rotor shaft 51.

[0038] The rear end of the shaft sleeve 53 in this embodiment is provided with a shaft sleeve hole 61, and the rear end of the shaft sleeve cavity 57 and the head of the rotor front cooling cavity 71 are connected through the shaft sleeve hole 61; the front end of the rotor shaft 51 is provided with a horizontal rotor shaft coolant inlet hole 62, and the rear end of the rotor front cooling cavity 71 and the head of the rotor rear cooling cavity 72 are connected through the rotor shaft coolant inlet hole 62; the rotor shaft 51 is provided with a rotor shaft radial through hole 63, and the rear end of the rotor rear cooling cavity 72 and the coolant return flow The heads of the cavities 73 are connected through the rotor shaft radial through hole 63; the rotor shaft 51 is provided with a rotor shaft coolant return hole 64, and the protective gear 24 is provided with a gear coolant return hole 65, which is aligned with the rotor shaft coolant return hole 64, and the tail of the coolant return cavity 73 passes through the rotor shaft coolant return hole 64 and the gear coolant return hole 65 in turn and is connected with the gear box cavity 23 in the gear box 2; the bottom of the gear box 2 is provided with a coolant output hole.

[0039] The rotor front cooling cavity 71, the rotor rear cooling cavity 72 and the coolant return cavity 73 in this embodiment are all annular structures, which allows the coolant to have a more sufficient heat exchange area with the rotor 54 in the cavity. The number of the sleeve holes 61 on the sleeve 53 is 4 to 8, the number of the rotor shaft coolant inlet holes 62, the number of the rotor shaft radial through holes 63 and the number of the rotor shaft coolant return holes 64 on the rotor shaft 51 are all 4 to 8, and the number of the gear coolant return holes 65 on the protective gear 24 is equal to the number of the rotor shaft coolant return holes 64.

[0040] The rotor cooling method of the dual-motor screw vacuum pump with built-in rotor cooling in this embodiment is as follows: the coolant used for cooling enters the coolant input hole 13 through an external drive pump, and the pumping flow rate of the coolant is usually designed to be 0.1-1 m / s, and passes through the rotor shaft cooling channel 55, the shaft sleeve cooling channel 56, the shaft sleeve cavity 57, the shaft sleeve hole 61, the rotor front cooling cavity 71, the rotor shaft coolant inlet hole 62, the rotor rear cooling cavity 72, the rotor shaft radial through hole 63, the coolant reflux cavity 73 and the rotor shaft coolant reflux hole 64 to form a coolant channel, and then enters the gear box cavity 23 of the gear box 2 through the gear coolant reflux hole 65, and flows out from the coolant output hole of the gear box 2. The coolant output hole is opened at the bottom of the gear box 2 and is connected to the drive pump, thereby forming a whole coolant circulation loop, thereby completing the effective cooling of the entire rotor assembly from the inside out. Normally, the entire coolant circulation loop first flows in from the exhaust side of the screw vacuum pump, then passes through the intake side of the screw vacuum pump, and finally is discharged from the exhaust side, which has a double cooling effect on the exhaust side with a higher temperature, making the temperature of the rotor 54 more balanced and the cooling effect better.

[0041] In this embodiment, the thickness of the rotor front cooling cavity 71, the rotor rear cooling cavity 72 and the coolant reflux cavity 73 are relatively narrow, while the apertures of the shaft sleeve hole 61, the rotor shaft coolant inlet hole 62, the rotor shaft radial through hole 63, the rotor shaft coolant reflux hole 64 and the gear coolant reflux hole 65 are relatively large. This structure is conducive to the rapid flow of coolant in different cavities, which is conducive to improving the cooling effect.

[0042] In addition, it should be noted that the shapes and names of the parts and components of the specific embodiments described in this specification may be different, and the above content described in this specification is only an example of the structure of the present invention. All equivalent changes or simple changes made based on the structure, features and principles described in the patent concept of the present invention are included in the protection scope of the patent of the present invention. Technicians in the technical field of the present invention can make various modifications or supplements to the specific embodiments described or replace them in a similar manner, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A dual-motor screw vacuum pump with internal rotor cooling, comprising a motor housing (1), a gear box (2), a pump housing (3) and a front end cover (4), wherein one end of the motor housing (1) is fixed to one end of the gear box (2), the other end of the gear box (2) is fixed to one end of the pump housing (3), a gear box cavity (23) is provided in the gear box (2), and the front end cover (4) is fixed to the other end of the pump housing (3), characterized in that: The invention also comprises two sets of rotor mechanisms (5), each set of rotor mechanisms (5) comprises a rotor assembly, a motor (14) and a protection gear (24), one end of the rotor assembly is mounted on the other end of the motor housing (1), the middle part of the rotor assembly is mounted on the other end of the gear box (2), the front half of the rotor assembly is a cantilever structure and is located in the pump housing (3), the motor (14) is mounted on the rotor assembly, the motor (14) is located in the motor housing (1), the protection gear (24) is mounted on the rotor assembly, the protection gear (24) is located in the gear box cavity (23) of the gear box (2), and a cooling liquid channel is provided inside the rotor mechanism (5); the two sets of rotor mechanisms (5) are mounted side by side, the teeth of one protection gear (24) in the two sets of rotor mechanisms (5) are embedded in the tooth grooves of the other protection gear (24), but the two protection gears (24) in the two sets of rotor mechanisms (5) do not contact each other.

2. The dual-motor screw vacuum pump with built-in rotor cooling according to claim 1, characterized in that: The rotor assembly comprises a rotor shaft (51), a shaft sleeve (52), a shaft sleeve (53), and a rotor (54); the front half of the rotor shaft (51) is sleeved in the rear half of the rotor (54); a shaft sleeve installation cavity (58) is formed between the front ends of the rotor shaft (51) and the rotor (54); the shaft sleeve (53) is fixed to the front end of the rotor shaft (51); the shaft sleeve (53) is located in the shaft sleeve installation cavity (58); the shaft sleeve (52) is sleeved in the rotor shaft (51) and is located in the front half of the rotor shaft (51); the motor (14) and the protective gear (24) are both directly mounted on the rotor shaft (51); and the two rotors (54) in the two sets of rotor mechanisms (5) are matched with each other.

3. The dual-motor screw vacuum pump with built-in rotor cooling according to claim 2, characterized in that: The motor housing (1) comprises a No. 1 bearing (11) and a bearing seat (12), the bearing seat (12) being fixed to the other end of the motor housing (1), and the rear end of the rotor shaft (51) being mounted on the bearing seat (12) via the No. 1 bearing (11); the gear box (2) comprises a No. 2 bearing (22), the other end of the gear box (2) being provided with a bearing hole (21), the No. 2 bearing (22) being mounted in the bearing hole (21), and the middle portion of the rotor shaft (51) being mounted on the No. 2 bearing (22).

4. The dual-motor screw vacuum pump with built-in rotor cooling according to claim 2 or 3, characterized in that: The rotor shaft (51) is a hollow structure, and a rotor shaft cooling channel (55) is provided in the rotor shaft (51); the shaft sleeve (52) is a hollow structure, and a shaft sleeve cooling channel (56) is provided in the shaft sleeve (52), and the head of the shaft sleeve cooling channel (56) is connected to the tail of the rotor shaft cooling channel (55); a shaft sleeve cavity (57) is provided in the shaft sleeve (53), and the head of the shaft sleeve cavity (57) is connected to the tail of the shaft sleeve cooling channel (56); the rotor (54) is a hollow structure, and a cover (59) is provided at the front end of the rotor (54).

5. The dual-motor screw vacuum pump with built-in rotor cooling according to claim 4, characterized in that: The bearing seat (12) is provided with a coolant input hole (13), and the coolant input hole (13) is connected to the head of a rotor shaft cooling channel (55) in the rotor shaft (51).

6. The dual-motor screw vacuum pump with built-in rotor cooling according to claim 5, characterized in that: A rotor front cooling chamber (71) is formed between the outer wall of the shaft sleeve (53) and the inner wall of the rotor (54), a rotor rear cooling chamber (72) is formed between the outer wall of the front of the rotor shaft (51) and the inner wall of the rotor (54), and a coolant reflux chamber (73) is formed between the outer wall of the rear half of the shaft sleeve tube (52) and the inner wall of the rotor shaft (51).

7. The dual-motor screw vacuum pump with built-in rotor cooling according to claim 6, characterized in that: The shaft sleeve (53) is provided with a shaft sleeve hole (61) at the rear end, and the rear end of the shaft sleeve cavity (57) and the head of the rotor front cooling cavity (71) are communicated through the shaft sleeve hole (61); the front end of the rotor shaft (51) is provided with a horizontal rotor shaft coolant inlet hole (62), and the rear end of the rotor front cooling cavity (71) and the head of the rotor rear cooling cavity (72) are communicated through the rotor shaft coolant inlet hole (62); the rotor shaft (51) is provided with a rotor shaft radial through hole (63), and the rear end of the rotor rear cooling cavity (72) and the coolant return cavity ( The heads of the gear shaft (73) are connected via a rotor shaft radial through hole (63); the rotor shaft (51) is provided with a rotor shaft coolant return hole (64), the protective gear (24) is provided with a gear coolant return hole (65), the gear coolant return hole (65) and the rotor shaft coolant return hole (64) are aligned, the tail of the coolant return cavity (73) passes through the rotor shaft coolant return hole (64) and the gear coolant return hole (65) in sequence and is connected to the gear box cavity (23) in the gear box (2); the bottom of the gear box (2) is provided with a coolant output hole.

8. The dual-motor screw vacuum pump with built-in rotor cooling according to claim 7, characterized in that: The rotor front cooling cavity (71), the rotor rear cooling cavity (72) and the coolant return cavity (73) are all annular structures; the number of the sleeve holes (61) on the sleeve (53) is 4 to 8, the number of the rotor shaft coolant inlet holes (62), the number of the rotor shaft radial through holes (63) and the number of the rotor shaft coolant return holes (64) on the rotor shaft (51) are all 4 to 8, and the number of the gear coolant return holes (65) on the protective gear (24) is equal to the number of the rotor shaft coolant return holes (64).

9. The dual-motor screw vacuum pump with built-in rotor cooling according to claim 2 or 3, characterized in that: The material of the rotor (54) is aluminum, magnesium-aluminum alloy or titanium alloy, and the material of the pump housing (3) is aluminum, magnesium-aluminum alloy or titanium alloy.

10. A rotor cooling method for a dual-motor screw vacuum pump with built-in rotor cooling as claimed in claim 7 or 8, characterized in that: The coolant used for cooling enters through the coolant input hole (13), passes through the rotor shaft cooling channel (55), the shaft sleeve cooling channel (56), the shaft sleeve cavity (57), the shaft sleeve hole (61), the rotor front cooling cavity (71), the rotor shaft coolant inlet hole (62), the rotor rear cooling cavity (72), the rotor shaft radial through hole (63), the coolant return cavity (73) and the rotor shaft coolant return hole (64) to form a coolant channel, then enters the gear box cavity (23) of the gear box (2) through the gear coolant return hole (65), and flows out from the coolant output hole of the gear box (2), thereby completing the cooling of the entire rotor assembly.

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