Vacuum pump unit

Abstract

The invention provides a vacuum pump unit which comprises a vacuum pump body and a shell assembly, the shell assembly comprises a motor base, a shell base and an air inlet base, and the motor base is provided with a mounting chamber used for mounting motor components; the shell base comprises an outer cover plate, an inner clamping sleeve and a bottom sealing plate transversely arranged between the outer cover plate and the inner clamping sleeve, a forming groove communicated with the inner side of the inner clamping sleeve is formed in the bottom face of the bottom sealing plate, and when the shell base is fixed to the motor base, the bottom of the forming groove is closed, and a flowing space allowing gas to flow through is formed; the left-handed screw and the right-handed screw are jointly arranged on the inner side of the inner jacket, and the air inlet seat is fixed to the top of the inner jacket to serve as an air inlet connector. The outer side of the motor base is fixedly connected with a connecting pipeline serving as an air outlet connector, and the connecting pipeline communicates with the forming groove. The side face of the shell base is further provided with an air blowing pipeline communicating with the forming groove. On the basis, the condition that particle impurities remain between the two screw rods when the vacuum pump unit works can be reduced, so that the service life of the vacuum pump unit is favorably maintained.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of air pressure control, and particularly relates to a vacuum pump unit. BACKGROUND

[0002] The working principle of the vacuum pump unit is mainly based on mechanical transmission and gas dynamics principle. Through the reciprocating or rotating movement of core components such as pistons, rotors or screws, the volume of the pump cavity is changed to realize the suction, compression and discharge of gas, so as to form a vacuum environment in a closed system.

[0003] The vacuum pump unit includes a horizontal vacuum pump unit and a vertical vacuum pump unit. When the vertical vacuum pump unit is used to extract gas, the particulate impurities mixed in the gas are sucked into the interior of the vertical vacuum pump unit. Taking a double-screw vacuum pump unit as an example, the particulate impurities are accumulated between the two screws and are difficult to discharge, which easily causes the screws to be worn and the sealing effect to be weakened. Moreover, with the accumulation of the particulate impurities, the two screws may be stuck, which is not conducive to maintaining the service life of the vacuum pump unit and needs to be improved. SUMMARY

[0004] Therefore, the present application provides a vacuum pump unit, which can reduce the accumulation of particulate impurities between the two screws when the vacuum pump unit is working, so as to facilitate the maintenance of the service life of the vacuum pump unit.

[0005] The vacuum pump unit provided by the present application adopts the following technical scheme: A vacuum pump unit includes a vacuum pump main body and a shell assembly arranged outside the vacuum pump main body. The vacuum pump main body includes a left-hand screw, a right-hand screw and two groups of motor components. The left-hand screw and the right-hand screw are respectively fixedly connected to the output ends of the two groups of motor components. The shell assembly includes a motor seat, a shell seat and an air inlet seat. The motor seat is provided with a vertical through installation chamber, and the motor component is fixedly installed in the installation chamber. The shell seat includes an outer cover plate, an inner clamping sleeve and a bottom sealing plate horizontally arranged between the outer cover plate and the inner clamping sleeve. The bottom surface of the bottom sealing plate is provided with a shaped groove in communication with the inner side of the inner clamping sleeve. When the shell seat is fixed to the motor seat, the bottom of the shaped groove is closed and forms a flow space for gas flow. The left-hand screw and the right-hand screw are arranged on the inner side of the inner clamping sleeve. The air inlet seat is fixed to the top of the inner clamping sleeve as an air inlet interface. The outer side of the motor seat is fixedly connected with a connecting pipeline as an air outlet interface. The connecting pipeline is in communication with the shaped groove. The side surface of the shell seat is further provided with a gas blowing pipeline in communication with the shaped groove. The gas blowing pipeline and the exhaust pipeline are arranged on two opposite side surfaces of the shell assembly.

[0006] Optionally, the vacuum pump unit further comprises a unit frame, a circuit base plate being fixed to an inner bottom wall of the unit frame, a closed control chamber being formed between the circuit base plate and the unit frame, a control element for controlling the vacuum pump unit being installed inside the control chamber, and a first nitrogen filling pipe for filling nitrogen into the control chamber is connected to an outer side of the circuit base plate; The motor seat is fixed to the top of the circuit base plate. The inner bottom of the motor seat has a structural cavity. A linkage structure for making the two motor components rotate synchronously is installed inside the structural cavity. The circuit base plate is provided with a first opening connected to the structural cavity, and the inner top wall of the structural cavity is provided with a second opening connected to the installation chamber.

[0007] Optionally, the motor component includes a motor stator fixed to the inside of the installation chamber, a motor rotor rotatably engaged with the motor stator, and a bearing seat for fixing the motor rotor. A nitrogen flow channel is provided between the motor rotor, the bearing seat and the corresponding left-handed screw / right-handed screw. One end of the nitrogen flow channel is connected to the structural cavity, and the other end of the nitrogen flow channel is connected to the flow space; the nitrogen pressure in the nitrogen flow channel is greater than the gas pressure inside the flow space.

[0008] Optionally, the bearing seat is fixedly installed on the top of the motor seat, and the bearing seat is provided with an integrally formed retaining ring, which is matched and installed inside the installation chamber; an annular pad is embedded in the outer peripheral surface of the retaining ring, and the top surface of the motor seat is provided with an embedding groove connected to the installation chamber, and the annular pad is fixed to the bottom wall of the embedding groove by fasteners to realize the vertical positioning of the bearing seat.

[0009] Optionally, the nitrogen flow channel includes a first channel opened in the motor base and a second channel opened in the bearing base, one end of the first channel penetrates the top wall of the structural cavity, and the other end penetrates the bottom wall of the embedding groove; a support ring is protruding from the bottom of the annular pad, and the annular pad is suspended by the support ring, and a first air gap is formed between the annular pad and the inner wall of the embedding groove and between the annular pad and the bearing base; The second channel includes a first inner hole opened on the outer side surface of the retaining ring and a second inner hole opened on the outer side surface of the bearing seat. The first inner hole is connected to the first air gap, and the first inner hole and the second inner hole are connected to each other. The right-handed screw is fixed to the motor rotor and partially sleeved on the bearing seat. There is a second air gap between the right-handed screw and the bearing seat. The bottom of the second air gap is connected to the flow space. A damping structure is provided between the bearing seat and the right-handed screw to force the nitrogen in the second inner hole to enter the flow space through the second air gap.

[0010] Optionally, the damping structure includes a plurality of piston rings embedded in the outer peripheral side of the bearing seat, and the number of piston rings located above the second inner hole air outlet end is greater than the number of piston rings located below the second inner hole air outlet end.

[0011] Optionally, the nitrogen flow channel further comprises a third inner hole opened on the top surface of the bearing seat, the first inner hole, the second inner hole and the third inner hole are in communication with each other; the third air gap is formed between the bearing seat and the motor rotor, and the third air gap is in communication with the second air gap; The outer diameter of the clamping ring is matched with the inner diameter of the mounting chamber, and a closed transition space is formed between the clamping ring and the motor stator in the fixed state; the middle part of the motor rotor is provided with a communication passage, one end of the communication passage is in communication with the third air gap, the other end of the communication passage is in communication with the transition space, and the outer side surface of the motor base is connected with a second nitrogen filling pipe in communication with the transition space.

[0012] Optionally, the motor rotor comprises a first shaft segment, a second shaft segment and a third shaft segment with the outer diameter size gradually decreasing, the first shaft segment is used for matching with the right-handed screw rod, the second shaft segment is located on the inner side of the bearing seat and forms the third air gap with the inner circumferential wall of the bearing seat, and the third shaft segment is installed on the inner side of the clamping ring through the bearing; the second shaft segment and the inner bottom wall of the bearing seat are spaced from each other to form a negative pressure area, and the width of the negative pressure area is greater than the width of the third air gap.

[0013] Optionally, the outer cover plate and the inner cover plate are spaced from each other to form a cooling space, and the top of the outer cover plate is fixed with a cover plate for closing the cooling space; the bottom of the cover plate is fixed with a heat exchange coil, the heat exchange coil is arranged on the outer circumferential side of the inner jacket, and the two ends of the heat exchange coil are jointly connected with a circulation system for circulating water.

[0014] Optionally, the motor base and the mounting chamber have a partitioned cooling chamber, the two opposite side surfaces of the motor base are respectively provided with an opening in communication with the cooling chamber, and a side sealing plate is matched and installed at the opening; the side surface of the motor base is provided with a cooling inlet pipe and a cooling outlet pipe in communication with the cooling chamber, and the cooling inlet pipe and the cooling outlet pipe are jointly connected to the circulation system.

[0015] In summary, the present application has at least one of the following beneficial technical effects: 1. The gas inlet seat is provided as an air inlet of the vacuum pump body and connected with a pipeline to be vacuumized, and the connecting pipeline is provided as an air outlet of the vacuum pump body, so that the gas inside the gas inlet seat can be pumped to the flow space and discharged through the connecting pipeline by controlling the synchronous rotation of the left-handed screw rod and the right-handed screw rod, thereby achieving the vacuumizing effect.

[0016] 2. When the vacuum pump unit is operated, the particulate impurities mixed in the air to be vacuumized will accumulate in the flow space, at this time, the positive pressure air is continuously blown into the flow space through the blowing pipeline, so that the particulate impurities in the flow space can be blown out through the connecting pipeline, thereby reducing the wear and jamming phenomenon of the vacuum pump unit during operation; and the positive pressure provided by the blowing pipeline is beneficial to the discharge of the gas in the flow space, which can ensure the vacuumizing effect of the vacuum pump unit to a certain extent, and has the effect of energy saving and consumption reduction.

[0017] 3. The first nitrogen filling pipe fills nitrogen into the control chamber, and the nitrogen can protect the control elements in the control chamber as an inert gas. The nitrogen enters the inside of the structure chamber through the first opening, and enters the inside of the mounting chamber through the second opening, which can protect the linkage structure and the motor components, so as to ensure that the vacuum pump unit has a good service life.

[0018] 4. The second nitrogen filling pipe fills nitrogen into the transition space, and the nitrogen can flow into the first inner hole after passing through the communication gas path, the third gas gap and the third inner hole in sequence. The nitrogen after confluence can be discharged through the second inner hole and enter the flow space, so as to discharge the particulate impurities and wet gas between the bearing seat and the motor rotor and between the bearing seat and the right-handed screw, and the vacuum pump unit can maintain a good service life.

[0019] 5. The circulating mechanism circulates water to the cooling area and the cooling chamber, which can cool the vacuum pump unit, so that the temperature of the vacuum pump unit is maintained within a suitable range, and the vacuum pump unit can also maintain a good service life. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is a schematic diagram of the overall structure of the embodiment; Figure 2 is a schematic diagram of the overall structure of the embodiment, mainly showing the specific structure of the unit frame and the shell assembly; Figure 3 is a schematic diagram of the overall structure of the embodiment in another direction, mainly showing the specific structure of the vacuum pump main body and the shell assembly; Figure 4 is a schematic diagram of the structure of the motor seat, the annular gasket and the fastener in the embodiment; Figure 5 is Figure 3 is an enlarged view of A in FIG. 8; Figure 6 is a schematic diagram of the structure of the two bearing seats in the embodiment; Figure 7 is a top view of the shell seat in the embodiment; Figure 8 is a bottom view of the shell seat in the embodiment; Figure 9 is Figure 5 is an enlarged view of B in FIG. 8; Figure 10 is a schematic diagram of the structure of the first channel in the embodiment; Figure 11 is a schematic diagram of the structure of the transition space in the embodiment.

[0021] Explanation of reference signs: 1, main body of vacuum pump; 11, left-hand screw rod; 12, right-hand screw rod; 121, second air gap; 13, motor stator; 14, motor rotor; 141, communication air passage; 142, first shaft section; 143, second shaft section; 144, third shaft section; 145, negative pressure area; 15, bearing seat; 151, clamping ring; 152, inner concave ring groove; 153, cutout part; 154, third air gap; 155, damping structure; 156, piston ring; 16, annular gasket plate; 161, half ring plate; 162, fastener; 163, support ring; 164, first air gap; 17, transition space; 2, housing assembly; 21, motor seat; 211, mounting chamber; 212, structural cavity; 213, embedded groove; 214, connecting pipeline; 215, second through port; 216, cooling chamber; 218, side sealing plate; 22, housing seat; 221, outer cover plate; 222, inner clamping sleeve; 223, bottom sealing plate; 224, formed groove; 225, exhaust pipeline; 226, blowing pipeline; 227, cooling space; 228, cover plate; 229, heat exchange coil; 23, air inlet seat; 24, flow space; 25, second nitrogen filling pipe; 3, unit frame; 31, line bottom plate; 311, first through port; 32, control chamber; 33, line cover plate; 34, first nitrogen filling pipe; 4, linkage structure; 5, nitrogen flow channel; 51, first channel; 511, shunt pipe; 52, second channel; 53, first inner hole; 54, second inner hole; 55, third inner hole; 6, circulation system; 61, cooling inlet pipe; 62, cooling outlet pipe. DETAILED DESCRIPTION

[0022] The following will be described in detail in combination with the accompanying drawings. Figure 1 - the accompanying drawings Figure 11 The application is further described in detail.

[0023] The embodiment of the application discloses a vacuum pump unit.

[0024] Reference will be made to Figure 1 , Figure 2The utility model provides a vacuum pump unit, including unit frame 3, vacuum pump main body 1 and casing assembly 2, wherein, unit frame 3 is fixedly arranged on ground base, the inner bottom wall of unit frame 3 is fixed with circuit bottom plate 31, the section shape of circuit bottom plate 31 is U-shaped setting, in fixed state, circuit bottom plate 31 can form closed control chamber 32 with unit frame 3, control chamber 32 can be installed inside control element (not shown in drawing) for controlling vacuum pump unit, for example circuit board, control valve, speed regulator etc., the surface of circuit bottom plate 31 is provided with operation window, and the inside control element can be installed or disassembled through operation window, and the top surface of circuit bottom plate 31 is detachably fixed with circuit cover plate 33, and circuit cover plate 33 normally blocks operation window, can make control chamber 32 inside keep closed state.

[0025] Referring to Figure 3 Vacuum pump main body 1 includes left-hand screw rod 11, right-hand screw rod 12 and two groups of motor components, left-hand screw rod 11 and right-hand screw rod 12 are fixedly connected to the output end of two groups of motor components respectively, and left-hand screw rod 11 and right-hand screw rod 12 are partially engaged transmission between each other.It needs to be explained here that the connecting mode of left-hand screw rod 11 and motor component and the connecting mode of right-hand screw rod 12 and motor component are corresponding same, in the embodiment, the connecting mode of right-hand screw rod 12 is taken as an example to be described, and the connecting mode of left-hand screw rod 11 and motor component will not be expanded.

[0026] Specifically, the motor component includes motor stator 13, motor rotor 14 and bearing seat 15, and referring back to Figure 2 Casing assembly 2 includes motor seat 21, casing seat 22 and air inlet seat 23, wherein, motor seat 21 is fixedly installed on the top of circuit bottom plate 31, and referring back to Figure 4 The middle part of motor seat 21 is provided with the installation chamber 211 that is vertically through, the number of installation chamber 211 is provided with two, and two motor stators 13 are fixedly installed in two installation chambers 211, and motor rotor 14 is rotatably arranged on the inner side of motor stator 13.The inner bottom of motor seat 21 has the structure cavity 212, and the structure cavity 212 is communicated with two installation chambers 211;The inside of structure cavity 212 is used for installing the linkage structure 4 for making two motor components synchronous rotation, and the specific structure of linkage structure 4 is conventional design in the art, and not the focus of the case to be protected, thus not expanded here.

[0027] Referring to Figure 5The bearing seat 15 is fixedly installed on the top of the motor base 21, and the bottom of the bearing seat 15 is provided with an integral clamping ring 151, the outer diameter of the clamping ring 151 is equal to the inner diameter of the installation chamber 211, so that the clamping ring 151 can be matched and installed on the inner side of the installation chamber 211. In addition, the outer circumferential surface of the clamping ring 151 is provided with an inner concave ring groove 152, and the annular backing plate 16 is installed in the inner concave ring groove 152. The annular backing plate 16 includes two half ring plates 161. The top surface of the motor base 21 is provided with an embedded groove 213, which is in communication with each installation chamber 211, and the shape and size of the embedded groove 213 are larger than those of the installation chamber 211. In the fixed state, the two half ring plates 161 can be located in the embedded groove 213, and the half ring plate 161 is fixed to the inner bottom wall of the embedded groove 213 by the fastener 162, thereby realizing the vertical positioning of the bearing seat 15. In the embodiment, the fastener 162 is threaded through the structure cavity 212 to the embedded groove 213 and is screwed with the half ring plate 161.

[0028] Referring to Figure 6 It should be noted that the side surface of the bearing seat 15 in the embodiment is also provided with a cutout portion 153, and the two bearing seats 15 between the two groups of motor components are abutted with each other through the cutout portion 153, thereby realizing the circumferential rotational positioning of the bearing seat 15. Then, the vertical positioning of the annular backing plate 16 can stably fix the bearing seat 15 on the top of the motor base 21.

[0029] Referring to Figure 7 The housing seat 22 is fixed to the top of the motor base 21. The housing seat 22 specifically includes an outer cover plate 221, an inner clamping sleeve 222, and a bottom sealing plate 223 transversely arranged between the outer cover plate 221 and the inner clamping sleeve 222, and the three are integrally formed. Referring to Figure 3 The inner clamping sleeve 222 is hollow on the inner side, and the shape of the inner clamping sleeve 222 is matched with the shape of the two installation chambers 211. In the fixed state, the two installation chambers 211 can be commonly opposite to the inner side of the inner clamping sleeve 222. The left-handed screw rod 11 and the right-handed screw rod 12 are commonly installed on the inner side of the inner clamping sleeve 222 and locally meshed, and the left-handed screw rod 11 and the right-handed screw rod 12 are respectively fixed to the motor rotors 14 of the two groups of motor components. Each motor rotor 14 is arranged on the inner side of the motor stator 13, and each motor rotor 14 is fixed with the bearing seat 15 through the bearing. The left-handed screw rod 11 and the right-handed screw rod 12 are respectively fixedly sleeved on the top end of the motor rotor 14. When the motor rotor 14 rotates, the left-handed screw rod 11 / right-handed screw rod 12 can rotate with the motor rotor 14.

[0030] Referring to Figure 8 The bottom sealing plate 223 of the housing seat 22 is provided with a formed groove 224 on the bottom surface, and the formed groove 224 is in communication with the inner side of the inner clamping sleeve 222. Back to Figure 2When the shell seat 22 is fixed to the motor seat 21, the bottom of the shaped groove 224 is blocked by the motor seat 21 and the bearing seat 15, and is in a closed state, thereby forming the flow space 24. The outer side of the motor seat 21 is fixedly connected with the connecting pipeline 214, and the connecting pipeline 214 is in communication with the shaped groove 224, so that in the fixed state, the connecting pipeline 214 can be in communication with the flow space 24 to serve as a gas outlet interface. The air inlet seat 23 is fixed to the top of the inner jacket 222, and the inner side of the air inlet seat 23 has the same shape as the inner jacket 222. The air inlet seat 23 is arranged to serve as an air inlet interface of the vacuum pump body 1 and is connected with a pipeline that needs to be vacuumized. By controlling the synchronous rotation of the left-handed screw rod 11 and the right-handed screw rod 12, the gas on the inner side of the air inlet seat 23 can be pumped to the flow space 24 and discharged through the connecting pipeline 214, thereby achieving the vacuumizing effect.

[0031] The side surface of the shell seat 22 is connected with the air blowing pipeline 226, which is in communication with the shaped groove 224 and in communication with the flow space 24 in the fixed state. The air blowing pipeline 226 and the exhaust pipeline 225 are arranged on the two opposite side surfaces of the shell assembly 2. It can be seen that when the vacuum pump set is operated, the particulate impurities mixed in the evacuated air will fall into and accumulate in the flow space 24 under the action of gravity. At this time, the positive pressure air is continuously blown into the inner side of the flow space 24 through the air blowing pipeline 226, so that the particulate impurities in the flow space 24 can be blown out through the connecting pipeline 214, thereby reducing the wear and tear and the jamming phenomenon of the vacuum pump set during operation. At the same time, since the air blowing pipeline 226 is connected to the flow space 24, it will not affect the vacuumizing effect of the inner side of the inner jacket 222, and the positive pressure provided by the air blowing pipeline 226 is beneficial to the discharge of the gas in the flow space 24, which can ensure the vacuumizing effect of the vacuum pump set to a certain extent and has the effect of energy saving and consumption reduction.

[0032] Referring to Figure 2 The circuit bottom plate 31 is provided with a first through port 311 in communication with the structure cavity 212. Referring to Figure 4 The inner top wall of the structure cavity 212 is provided with a second through port 215 in communication with the mounting chamber 211. Referring to Figure 1 The top of the circuit bottom plate 31 is vertically connected with a first nitrogen filling pipe 34, through which nitrogen gas can be filled into the control chamber 32, thereby protecting each control element in the control chamber 32. The nitrogen gas enters the inside of the structure cavity 212 through the first through port 311 and enters the inside of the mounting chamber 211 through the second through port 215, which can respectively protect the linkage structure 4 and the motor components, so as to ensure that the vacuum pump set has a good service life.

[0033] In addition, referring to Figure 5, the motor rotor 14, the bearing seat 15 and the corresponding left-handed screw rod 11 / right-handed screw rod 12 are jointly provided with a nitrogen flow channel 5, one end of the nitrogen flow channel 5 is in communication with the structure cavity 212, the other end of the nitrogen flow channel 5 is in communication with the flow space 24, and the nitrogen pressure in the nitrogen flow channel 5 is greater than the gas pressure inside the flow space 24; the following still takes the right-handed screw rod 12 as an example for description.

[0034] Referring to Figure 5 , Figure 9 In the embodiment, the bottom of the half ring plate 161 is provided with a supporting ring 163, the supporting ring 163 is located in the half ring plate 161 and is integrally formed with the half ring plate 161, when the half ring plate 161 is fixed to the motor seat 21 through the fastener 162, the supporting ring 163 abuts against the inner bottom wall of the embedding groove 213, the arrangement of the supporting ring 163 makes the half ring plate 161 in a suspended state, at this time, the half ring plate 161 and the inner wall of the embedding groove 213, and the half ring plate 161 and the bearing seat 15 can be spaced apart and form a first air gap 164.

[0035] The right-handed screw rod 12 is fixedly sleeved at the top end of the motor rotor 14, and the right-handed screw rod 12 is partially sleeved on the bearing seat 15; the second air gap 121 is formed between the right-handed screw rod 12 and the bearing seat 15, and the bottom of the second air gap 121 is in communication with the flow space 24; the third air gap 154 is formed between the bearing seat 15 and the motor rotor 14, and the third air gap 154 is in communication with the second air gap 121. In addition, the damping structure 155 is further arranged between the bearing seat 15 and the right-handed screw rod 12, and the damping structure 155 includes a plurality of piston rings 156 embedded on the outer circumferential side of the bearing seat 15, and all the piston rings 156 are equidistantly arranged along the axis direction of the bearing seat 15.

[0036] Referring to Figure 10 The nitrogen flow channel 5 includes a first channel 51 and a second channel 52, the first channel 51 is formed in the motor seat 21, one end of the first channel 51 penetrates to the top wall of the structure cavity 212 and is connected with a shunt pipe 511, and the other end of the first channel 51 penetrates to the inner bottom wall of the embedding groove 213. As the first nitrogen filling pipe 34 gradually fills nitrogen into the inside of the control chamber 32, after the nitrogen fills the control chamber 32 and the structure cavity 212, the nitrogen can enter the embedding groove 213 through the first channel 51, and then enter the inside of the first air gap 164.

[0037] Back to Figure 5 The second channel 52 is arranged on the bearing seat 15, and the second channel 52 specifically includes a first inner hole 53, a second inner hole 54 and a third inner hole 55, and the first inner hole 53, the second inner hole 54 and the third inner hole 55 are in communication with each other; referring to Figure 9 The first inner hole 53 is formed on the outer side surface of the clamping ring 151, and the first inner hole 53 is in communication with the first air gap 164.

[0038] Back to Figure 5 , the second inner hole 54 is arranged on the outer side of the bearing seat 15, and the second inner hole 54 can be in communication with the second air gap 121. In this embodiment, the communication between the second inner hole 54 and the outer side of the bearing seat 15 is provided as the gas outlet end of the second inner hole 54. The number of piston rings 156 located above the gas outlet end of the second inner hole 54 is greater than the number of piston rings 156 located below the gas outlet end of the second inner hole 54. Based on this, when the nitrogen gas enters the first air gap 164 through the first channel 51, enters the second air gap 121 along the first inner hole 53 and the second inner hole 54, the resistance to the upward flow of the nitrogen gas is greater than the resistance to the downward movement of the nitrogen gas, thereby guiding the nitrogen gas into the flow space 24 and being discharged from the connecting pipeline 214 along with the gas.

[0039] The third inner hole 55 is arranged on the top surface of the bearing seat 15, and the third inner hole 55 is in communication with the third air gap 154. Referring to Figure 11 , in this embodiment, the outer diameter of the clamping ring 151 is equal to the inner diameter of the mounting chamber 211. In the fixed state, the clamping ring 151 and the motor stator 13 can form a closed transition space 17. The outer side of the motor seat 21 is connected with the second nitrogen charging pipe 25, and the second nitrogen charging pipe 25 can be in communication with the transition space 17, and is also used to charge nitrogen into the transition space 17.

[0040] The middle part of the motor rotor 14 is provided with a communication air path 141, one end of the communication air path 141 is in communication with the third air gap 154, and the other end of the communication air path 141 is in communication with the transition space 17. When the second nitrogen charging pipe 25 charges nitrogen into the transition space 17, the nitrogen can enter the third air gap 154 through the communication air path 141, and enter the second air gap 121 along the third air gap 154. At this time, the nitrogen can fill the second air gap 121, thereby forming an air barrier to limit the upward flow of nitrogen from the gas outlet end of the second inner hole 54. In addition, the nitrogen can enter the third inner hole 55 and flow together with the nitrogen in the first inner hole 53. The nitrogen after flowing together is discharged through the second inner hole 54 and enters the flow space 24, which can discharge the particulate impurities and wet gas between the bearing seat 15 and the motor rotor 14 and between the bearing seat 15 and the right-handed screw 12, and is more conducive to maintaining a good service life of the vacuum pump set.

[0041] In addition, referring to Figure 5 , the motor rotor 14 of the present application comprises a first shaft segment 142, a second shaft segment 143 and a third shaft segment 144 arranged in sequence from top to bottom, and the outer diameters of the first shaft segment 142, the second shaft segment 143 and the third shaft segment 144 are successively reduced. The first shaft segment 142 is used to match and connect with the right-handed screw 12, the second shaft segment 143 is located inside the bearing seat 15 and forms the third air gap 154 with the inner wall of the bearing seat 15, and the third shaft segment 144 is mounted inside the clamping ring 151 through a bearing.

[0042] In the embodiment, the second shaft segment 143 and the inner bottom wall of the bearing seat 15 are spaced apart to form a negative pressure area 145, and the width of the negative pressure area 145 is greater than the width of the third air gap 154. Based on this, when the nitrogen enters the third air gap 154 and moves to the second air gap 121, a negative pressure effect can be formed inside the negative pressure area 145. If there is a small particle impurity inside the negative pressure area 145, the particle impurity can move to a position close to the outer peripheral wall of the negative pressure area 145 under the action of negative pressure suction, and the particle impurity can also be prevented from being stuck between the motor rotor 14 and the bearing seat 15 to cause the motor to be stuck, thereby ensuring smooth operation of the vacuum pump set.

[0043] Back to Figure 3 , the outer cover plate 221 and the inner jacket 222 are spaced apart to form a cooling space 227, the outer cover plate 221 is bolted to the top of the cover plate 228, and the cover plate 228 can close the cooling space 227; the heat exchange coil 229 is fixed at the bottom of the cover plate 228, the heat exchange coil 229 is made of copper pipe and has good heat exchange capacity; the heat exchange coil 229 is arranged around the outer peripheral side of the inner jacket 222, and the two ends of the heat exchange coil 229, i.e. the water inlet end and the water outlet end of the heat exchange coil 229 are connected with the circulating system 6, water can be circulated in the heat exchange coil 229 through the circulating system 6, and then the temperature of the cooling space 227 is reduced by heat absorption, thereby achieving the effect of cooling the entire vacuum pump set. It should be noted that the circulating system 6 is a conventional design for those skilled in the art, and is not the focus of the present application, so it will not be described here.

[0044] In addition, the motor seat 21 is provided with a cooling chamber 216, and the cooling chamber 216 is separated from the mounting chamber 211; the two opposite sides of the motor seat 21 are respectively provided with an opening, each opening is communicated with the cooling chamber 216, and a side sealing plate 218 is matched and installed at the opening, so that the inside of the cooling chamber 216 is in a closed state; referring to Figure 4 , the side of the motor seat 21 is provided with a cooling inlet pipe 61 and a cooling outlet pipe 62 communicated with the cooling chamber 216, and the cooling inlet pipe 61 and the cooling outlet pipe 62 are connected with the circulating system 6. The cooling chamber 216 can also achieve the effect of cooling the vacuum pump set, which is beneficial to maintaining the service life of the vacuum pump set.

[0045] The above is a preferred embodiment of the present application, which does not limit the protection scope of the present application, therefore: any equivalent changes made on the basis of the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A vacuum pump unit, comprising a vacuum pump body (1) and a housing assembly (2) arranged outside the vacuum pump body (1), wherein: The vacuum pump body (1) comprises a left-handed screw (11), a right-handed screw (12) and two groups of motor components, wherein the left-handed screw (11) and the right-handed screw (12) are respectively fixedly connected to the output ends of the two groups of motor components; the housing assembly (2) comprises a motor seat (21), a housing seat (22) and an air inlet seat (23); the motor seat (21) is provided with a vertically through-going mounting chamber (211), and the motor component is fixedly mounted in the mounting chamber (211); The housing seat (22) includes an outer cover plate (221), an inner jacket (222), and a bottom sealing plate (223) arranged horizontally between the outer cover plate (221) and the inner jacket (222); the bottom surface of the bottom sealing plate (223) is provided with a forming groove (224) communicating with the inner side of the inner jacket (222); when the housing seat (22) is fixed to the motor seat (21), the bottom of the forming groove (224) is closed and a flow space (24) is formed for gas to flow through; the left-handed screw (11) and the right-handed screw (12) are jointly arranged on the inner side of the inner jacket (222); the air inlet seat (23) is fixed to the top of the inner jacket (222) to serve as an air inlet interface; A connecting pipe (214) serving as an air outlet interface is fixedly connected to the outside of the motor seat (21), and the connecting pipe (214) is connected to the forming groove (224); a blowing pipe (226) connected to the forming groove (224) is also provided on the side of the housing seat (22), and the blowing pipe (226) and the exhaust pipe (225) are respectively arranged on two opposite sides of the housing assembly (2).

2. The vacuum pump unit according to claim 1, characterized in that: The machine also includes a machine frame (3), wherein a circuit base plate (31) is fixed to the inner bottom wall of the machine frame (3), a closed control chamber (32) is formed between the circuit base plate (31) and the machine frame (3), a control element for controlling the vacuum pump unit is installed inside the control chamber (32), and a first nitrogen filling pipe (34) for filling nitrogen into the control chamber (32) is connected to the outer side of the circuit base plate (31); The motor base (21) is fixed to the top of the circuit base plate (31); the inner bottom of the motor base (21) has a structural cavity (212); a linkage structure (4) for causing two motor components to rotate synchronously is installed inside the structural cavity (212); the circuit base plate (31) is provided with a first opening (311) communicating with the structural cavity (212), and the inner top wall of the structural cavity (212) is provided with a second opening (215) communicating with the installation chamber (211).

3. The vacuum pump unit according to claim 2, characterized in that: The motor component comprises a motor stator (13) fixed to the inner side of the installation chamber (211), a motor rotor (14) rotatably engaged with the motor stator (13), and a bearing seat (15) for fixing the motor rotor (14); a nitrogen flow channel (5) is provided between the motor rotor (14), the bearing seat (15), and the corresponding left-handed screw (11) / right-handed screw (12); one end of the nitrogen flow channel (5) is connected to the structural cavity (212), and the other end of the nitrogen flow channel (5) is connected to the flow space (24); the nitrogen pressure in the nitrogen flow channel (5) is greater than the gas pressure inside the flow space (24).

4. The vacuum pump unit according to claim 3, characterized in that: The bearing seat (15) is fixedly mounted on the top of the motor seat (21), and the bearing seat (15) is provided with an integrally formed retaining ring (151), and the retaining ring (151) is matched and mounted on the inner side of the mounting chamber (211); an annular pad (16) is embedded in the outer peripheral surface of the retaining ring (151), and the top surface of the motor seat (21) is provided with an embedding groove (213) connected to the mounting chamber (211), and the annular pad (16) is fixed to the inner bottom wall of the embedding groove (213) by a fastener (162) to realize the vertical positioning of the bearing seat (15).

5. The vacuum pump unit according to claim 4, characterized in that: The nitrogen flow channel (5) includes a first channel (51) opened in the motor seat (21) and a second channel (52) opened in the bearing seat (15), one end of the first channel (51) penetrates the inner top wall of the structural cavity (212), and the other end penetrates the inner bottom wall of the embedding groove (213); the bottom of the annular pad (16) is protrudingly provided with a support ring (163), and the annular pad (16) is suspended by the support ring (163), and a first air gap (164) is formed between the annular pad (16) and the inner wall of the embedding groove (213), and between the annular pad (16) and the bearing seat (15); The second channel (52) includes a first inner hole (53) opened on the outer side of the retaining ring (151) and a second inner hole (54) opened on the outer side of the bearing seat (15), the first inner hole (53) is connected to the first air gap (164), and the first inner hole (53) and the second inner hole (54) are connected to each other; the right-handed screw (12) is fixed to the motor rotor (14) and partially sleeved on the bearing seat (15), a second air gap (121) is present between the right-handed screw (12) and the bearing seat (15), and the bottom of the second air gap (121) is connected to the flow space (24); a damping structure (155) is provided between the bearing seat (15) and the right-handed screw (12) for forcing the nitrogen in the second inner hole (54) to enter the flow space (24) through the second air gap (121).

6. The vacuum pump unit according to claim 5, characterized in that: The damping structure (155) includes a plurality of piston rings (156) embedded in the outer peripheral side of the bearing seat (15), and the number of piston rings (156) located above the air outlet end of the second inner hole (54) is greater than the number of piston rings (156) located below the air outlet end of the second inner hole (54).

7. The vacuum pump unit according to claim 5, characterized in that: The nitrogen flow channel (5) further includes a third inner hole (55) opened on the top surface of the bearing seat (15), the first inner hole (53), the second inner hole (54) and the third inner hole (55) are interconnected; a third air gap (154) is present between the bearing seat (15) and the motor rotor (14), and the third air gap (154) is connected to the second air gap (121); The outer diameter of the mounting ring (151) is adapted to the inner diameter of the mounting chamber (211); in a fixed state, a closed transition space (17) is formed between the mounting ring (151) and the motor stator (13); a connecting air path (141) is provided in the middle of the motor rotor (14); one end of the connecting air path (141) is connected to the third air gap (154), and the other end of the connecting air path (141) is connected to the transition space (17); and the outer side surface of the motor base (21) is connected to a second nitrogen filling pipe (25) connected to the transition space (17).

8. The vacuum pump unit according to claim 7, characterized in that: The motor rotor (14) includes a first shaft section (142), a second shaft section (143) and a third shaft section (144) with successively smaller outer diameters, the first shaft section (142) being used for matching and sleeve-engaging with the right-handed screw (12), the second shaft section (143) being located on the inner side of the bearing seat (15) and forming the third air gap (154) with the inner peripheral wall of the bearing seat (15), and the third shaft section (144) being mounted on the inner side of the retaining ring (151) through a bearing; the second shaft section (143) and the inner bottom wall of the bearing seat (15) are spaced apart from each other to form a negative pressure area (145), and the width of the negative pressure area (145) is greater than the width of the third air gap (154).

9. The vacuum pump unit according to claim 1, characterized in that: The outer cover plate (221) and the inner cover plate are spaced apart from each other and form a cooling space (227); a cover plate (228) for sealing the cooling space (227) is fixed to the top of the outer cover plate (221); a heat exchange coil (229) is fixed to the bottom of the cover plate (228); the heat exchange coil (229) is wound around the outer periphery of the inner jacket (222), and both ends of the heat exchange coil (229) are connected to a circulation system (6) for circulating water.

10. The vacuum pump unit according to claim 9, characterized in that: A partitioned cooling chamber (216) is provided between the motor base (21) and the installation chamber (211); two opposite sides of the motor base (21) are respectively provided with openings connected to the cooling chamber (216), and side sealing plates (218) are matched and installed at the openings; a cooling inlet pipe (61) and a cooling outlet pipe (62) connected to the cooling chamber (216) are provided on the side of the motor base (21); the cooling inlet pipe (61) and the cooling outlet pipe (62) are connected to the circulation system (6) together.

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