Vacuum pump

Abstract

A vacuum pump comprises a pump housing, a rotor and a bearing-drive unit, wherein the rotor comprises a pumping element and has a rotation axis defining an axial direction. The bearing-drive unit comprises bearing elements of magnetic bearings for supporting the rotor, an electric machine for driving the rotor and a bearing housing, the bearing elements and the rotor being arranged within the bearing housing. The bearing housing has a fixed connection with the pump housing, which fixed connection is arranged in the region of the electric machine in the axial direction.

Description

Technical Field

[0001] The present invention relates to a vacuum pump, particularly a turbomolecular pump, comprising a pump housing, a rotor with pumping elements, and a bearing-drive unit including bearing elements for supporting the rotor magnetic bearings and an electric motor for driving the rotor. Background Technology

[0002] This type of vacuum pump typically uses an active magnetic bearing as the magnetic bearing to support the pump rotor in a non-contact manner. Through this active magnetic bearing, the rotor is suspended in a predetermined spatial position between the stator components during vacuum pump operation.

[0003] The bearing elements of this type of magnetic bearing and the electric motor used to drive the rotor are typically housed together in a common bearing housing to form what is known as a main shaft for active magnetic support or an active magnetic support spindle, which can be integrated into the vacuum pump as a bearing-drive unit. This bearing-drive unit can be aligned and balanced with the rotor before being mounted together into the vacuum pump. For stability, the bearing-drive unit is typically secured to its axial upper or lower end, or to the magnetic support spindle, for example, to the lower part of the pump housing of a turbomolecular pump.

[0004] The installation of the bearing-drive unit or magnetically supported spindle and rotor is typically carried out from the upper side of the lower part of the pump casing. In this installation, the cabling required for the bearing elements of the magnetic bearing and the motor arrangement is often cumbersome because the necessary interfaces on the bearing-drive unit and motor are usually not easily accessible after the magnetically supported spindle is inserted. There is a risk of installation errors, such as cables getting caught.

[0005] Furthermore, if the housing of the bearing-drive unit or magnetic support spindle is fixed at its upper or lower axial end, the thermal contact between the bearing-drive unit and the pump housing may be insufficient. Typically, the motor driving the rotor is located in the middle of the bearing-drive unit or magnetic support spindle, which is the primary source of heat rise in the bearing-drive unit. Therefore, there is usually a certain distance before the bearing-drive unit is fixed at its upper or lower axial end, making it difficult for the motor's heat to dissipate through the fixing device. Additionally, fixing the bearing-drive unit or magnetic support spindle at its upper or lower axial end may cause some vibration inside the vacuum pump. Summary of the Invention

[0006] The purpose of this invention is to provide a vacuum pump whose bearing-drive unit or magnetically supported spindle is easy to install, and whose thermal connection and vibration performance of the bearing-drive unit are improved.

[0007] This objective is achieved by a vacuum pump having the features of claim 1. Advantageous improvements of the invention are given in the dependent claims, the description, and the drawings.

[0008] The vacuum pump (particularly a turbomolecular pump) includes a pump housing, a rotor with pumping elements and a rotating shaft defining an axial direction, and a bearing-drive unit. The bearing-drive unit includes bearing elements for supporting the rotor with magnetic bearings, a motor for driving the rotor, and a bearing housing, within which the bearing elements and the rotor are arranged. The bearing housing is fixedly connected to the pump housing, and this fixed connection is arranged axially within the region of the motor.

[0009] The magnetic bearing can be an active magnetic bearing, i.e., a type of magnetic bearing that adjusts the position of the vacuum pump rotor so that the rotor is suspended within the magnetic bearing during its operation. In this suspended state, the vacuum pump rotor therefore has no contact with any other components of the vacuum pump. It only comes into contact with the rolling bearing, also known as a safety or thrust bearing, in the event of an unexpected event deviating from normal vacuum pump operation, when the rotor deviates from its target position within the magnetic bearing. Furthermore, the rotor contacts the safety or thrust bearing when the vacuum pump is shut down.

[0010] If the magnetic bearing is an active magnetic bearing, then the bearing-drive unit can also be called an active magnetic support spindle. Within the bearing housing of the magnetic support spindle, both the bearing elements of the magnetic bearing and a motor or electric motor for driving the rotor can be arranged.

[0011] The fixed connection can be arranged in the motor region in the axial direction in such a way that the motor and the fixed connection at least partially overlap in the axial direction. For example, if the fixed connection is formed by a flange or protrusion on the outer side of the bearing housing of the bearing-drive unit, then when the vacuum pump is viewed from the radial outside, there is a certain area in both the axial and circumferential directions in which the bearing housing covers a portion of the outer surface of the motor.

[0012] In the axial direction, the motor of the vacuum pump can be arranged in the middle region of the bearing housing, that is, at approximately equal distances from the axial ends of the bearing housing or the magnetic support spindle. Therefore, the fixed connection between the bearing housing and the pump housing can also be arranged in the middle region of the bearing-drive unit or its bearing housing in the axial direction, thus being approximately equidistant from the two axial ends of the bearing housing. In other words, the axial distance of the fixed connection relative to the axial center of the bearing housing is less than its respective radial distance to the axial ends of the bearing housing. Therefore, the difference between the respective distances to the axial ends of the bearing housing can be less than the respective distances of the fixed connection to the axial ends of the bearing housing, that is, less than the smaller of the two axial distances.

[0013] One key feature of this vacuum pump is that, because the fixed connection is located approximately at the height of the motor in the axial direction, the distance between the fixed connection and the bearing housing is relatively small. Consequently, during vacuum pump operation, the heat generated by the motor can be transferred to the pump housing more directly than, for example, a fixed connection located at one axial end of the bearing housing. Better thermal coupling between the vacuum pump motor and the pump housing is achieved through a fixed connection at the height of the motor, such as a fixed connection located axially in the middle of the bearing housing.

[0014] Furthermore, when the fixed connection between the bearing housing and the pump housing is located approximately at the height of the motor in the axial direction, a more mechanically rigid connection is formed between the bearing-drive unit and the pump housing. This results in improved vibration performance of the vacuum pump during operation.

[0015] Furthermore, when the fixed connection between the bearing housing and the pump housing is approximately at the height of the motor in the axial direction, the wiring of the bearing-drive unit can be easily implemented. For example, in the case of a vertically arranged vacuum pump, when the fixed connection is approximately at the height of the motor in the axial direction, there is accessible space below the bearing-drive unit.

[0016] According to one embodiment, the fixed connection of the bearing housing can be formed with a portion of the pump housing, which has at least one cooling element. Since the fixed connection is also located in the region of the motor in the axial direction, in this embodiment, the motor heat generated during vacuum pump operation can be dissipated more efficiently because the distance between the motor and the cooling element is small due to the fixed connection. Therefore, in this embodiment, due to the arrangement of the fixed connection of the bearing housing, there is a direct and close connection between the motor of the vacuum pump and the cooling element in the pump housing portion, both in the radial and axial directions.

[0017] The cooling element can be designed to be water-cooled. The water-cooled portion of the pump casing that serves as this cooling element can have internal channels or cavities through which cooling water flows. Thus, the pump casing is effectively cooled.

[0018] Alternatively or additionally, the portion of the pump housing that forms a fixed connection with the bearing housing may have heat sinks. Therefore, these heat sinks can serve as a second cooling element, in addition to water cooling, to enhance the cooling of the motor.

[0019] Furthermore, if at least one cooling element is designed to be water-cooled, a portion of the water cooling can extend through the bearing-drive unit. In this embodiment, the channel or cavity for water cooling thus passes not only through the fixed connection portion of the bearing housing forming the bearing-drive unit within the pump housing, but also through the bearing-drive unit or its bearing housing. In this embodiment, the distance between the motor and the water cooling is further reduced, thereby allowing for more efficient cooling of the motor during vacuum pump operation.

[0020] According to another embodiment, the bearing housing may have an external protrusion or flange extending outward from the outer edge of the bearing housing in a radial direction perpendicular to the axial direction. Correspondingly, the pump housing may have an internal protrusion or flange extending inward from the inner edge of the pump housing in a radial direction. In this embodiment, the fixed connection between the bearing housing and the pump housing can be formed by connecting the external protrusion of the bearing housing and the internal protrusion of the pump housing.

[0021] Therefore, the fixed connection can be achieved at low cost between the two protrusions of the bearing housing and the pump housing. The two protrusions can be connected to each other, for example, by threaded connection, such as by screws extending in the axial direction, or by other means (e.g., by adhesive).

[0022] The internal protrusion of the pump housing can also be arranged axially between the external protrusion of the bearing housing and the pumping element of the rotor. Therefore, in this embodiment, the external protrusion or flange of the bearing housing and the pumping element of the rotor are located on opposite sides of the internal protrusion or flange of the pump housing.

[0023] When the vacuum pump is arranged vertically, i.e., when the rotor's axis of rotation extends vertically, in this embodiment, the external protrusion of the bearing housing of the bearing-drive unit or magnetic support spindle is positioned below the internal protrusion of the pump housing. In this vertically oriented vacuum pump, the bearing-drive unit or magnetic support spindle can be installed from its lower side after the vacuum pump rotor has been installed inside the pump housing. In this embodiment of the bearing-drive unit, its wiring (i.e., the wiring of the motor and the bearing elements of the magnetic bearing) can be performed with reduced workload. Furthermore, since the wiring is performed in a clear manner from below, the risk of accidentally catching cables is reduced.

[0024] If the external protrusion of the bearing housing is positioned on the opposite side of the pumping element of the rotor relative to the internal protrusion of the pump housing, the fixed connection can include a threaded connection that extends through the external protrusion of the bearing housing toward the pumping element. In this threaded connection, screws can pass through the external protrusion of the bearing housing in the axial direction, with their respective tips extending into the internal protrusion of the pump housing. In the case of a vacuum pump or a rotor with its rotating shaft arranged vertically, this threaded connection can be said to be achieved from below at low cost because the external protrusion of the bearing housing can be easily accessed from the outside.

[0025] Conversely, the external protrusion of the bearing housing may be arranged axially between the internal protrusion of the pump housing and the pumping element of the rotor. In other words, in this embodiment, the internal protrusion of the pump housing and the pumping element of the rotor may be arranged axially on opposite sides of the external protrusion of the bearing housing.

[0026] When the vacuum pump is arranged vertically, in this embodiment, the external protrusion of the bearing housing is therefore located above the internal protrusion of the pump housing. In this case, the bearing-drive unit or magnetic support spindle is then inserted into the pump housing from the top of the vertically oriented vacuum pump and is pre-connected to the rotor of the vacuum pump for this purpose.

[0027] In this embodiment, the bearing-drive unit can therefore be mounted together with the rotor and balanced, for example, by laser dynamic balancing, before the rotor and the assembly of the magnetic support spindle or bearing-drive unit are inserted into the pump housing from above. This simplifies the balancing process of the vacuum pump, as the bearing-drive unit or magnetic support spindle and rotor are already balanced before being inserted into the pump housing.

[0028] Furthermore, in this embodiment, the bearing-drive unit may have housing elements for securing stator components of one or more pump stages of the vacuum pump. These housing elements may, for example, be a Holweck stator of the vacuum pump. Therefore, the Holweck stator can be integrated into or connected to the bearing-drive unit or magnetic support spindle before being subsequently installed with the vacuum pump rotor. This reduces tolerances during vacuum pump component installation or mounting. Because the Holweck stator can be pre-connected and aligned with the bearing-drive unit or magnetic support spindle, the rotor components of the Holweck pump stage can be more precisely aligned relative to the Holweck stator. In other words, when the Holweck stator and Holweck rotor components are implemented or installed in the vacuum pump, the bearing-drive unit serves as a reference unit for the mounting of these components.

[0029] In the current embodiment, the external protrusion of the bearing housing is arranged axially between the internal protrusion of the pump housing and the pumping element of the rotor, i.e., above the pump housing protrusion, for example, when the rotor's axis of rotation is vertically oriented. The fixed connection may include a threaded connection extending through the internal protrusion of the pump housing toward the pumping element. In such a threaded connection, screws may pass axially through the internal protrusion of the pump housing, their respective tips extending into the external protrusion of the bearing housing.

[0030] In this embodiment and the embodiment described above that also features a threaded connection, the direction of extension of the threaded connection refers to the direction of movement of each screw when the screw is screwed into the protrusion of the corresponding housing to form a threaded connection. In other words, the respective direction of extension of the threaded connection extends from the respective head of the screw to its respective tip.

[0031] In an alternative embodiment, the fixed connection can be formed by pressing or shrinking the bearing housing into a portion of the pump housing. In this embodiment, protrusions in the bearing housing or pump housing are not necessary, although a press-fit or shrink-fit can be made between these protrusions to replace a threaded connection. The press-fit or shrink-fit also creates a large-area contact between the bearing housing and the pump housing, thereby improving thermal coupling between the bearing housing (and consequently the motor) and the pump housing.

[0032] In another alternative embodiment, the bearing housing may also include external threads, which may be designed to screw into the internal threads of a portion of the pump housing. In this embodiment, a protrusion on the bearing housing or pump housing is also unnecessary, although external and internal threads may be provided on the aforementioned protrusion to replace screws. In this embodiment, as the external threads of the bearing housing rotate within the internal threads of the pump housing, the axial position of the entire magnetic bearing (i.e., the position of the bearing element within the bearing-drive unit) can be adjusted or moved axially via the external threads on the bearing housing of the bearing-drive unit. This allows for adjustment and optimization of the axial position of the rotor or its rotor disk within the stator element of the turbomolecular pump stage, since the spatial position of the rotor during operation of the vacuum pump or turbomolecular pump is determined by the magnetic bearing. When the vacuum pump is running, the connection between the internal and external threads also creates a large-area contact between the bearing housing and the pump housing, through which heat from the vacuum pump motor can be efficiently dissipated.

[0033] In another alternative embodiment, the bearing housing may again have an external protrusion extending from the outer edge of the bearing housing in a radial direction perpendicular to the axial direction, and this external protrusion may form part of the pump housing. In this embodiment, the protrusion or flange of the bearing housing thus forms an intermediate part of the pump housing, located between its upper portion (where the pumping elements of the rotor may be located) and its lower housing (where the control and connection elements of the vacuum pump are typically located). This embodiment enables a compact structure for the vacuum pump.

[0034] Within the bearing-drive unit, the motor may also be arranged axially between the bearing elements of the magnetic bearing. In this embodiment, the motor may be located axially between the bearing elements for radially supporting the rotor, and these radial bearing elements are therefore arranged axially on both sides of the motor. By distributing the radial bearing elements of the magnetic bearing on both sides of the motor, the vibration performance of the vacuum pump can be improved. The bearing-drive unit may also include axial bearing elements, i.e., bearing elements for axially supporting the rotor, which are arranged, for example, axially outside the radial bearing elements and within the region of one or both axial ends of the bearing-drive unit. Attached Figure Description

[0035] The present invention will now be described with reference to the accompanying drawings, which illustrate preferred embodiments. In the drawings: Figure 1 A vacuum pump having a bearing-drive unit according to the invention is illustrated schematically. Detailed Implementation

[0036] exist Figure 1 The diagram schematically illustrates a vacuum pump 100 configured as a turbomolecular pump. The turbomolecular pump 100 includes a turbomolecular pump stage 102 and a Hallwick pump stage 104.

[0037] Furthermore, the turbomolecular pump 100 has a pump housing 110, which includes an upper portion 112, an intermediate portion 114, and a lower portion 116. The pump housing 110 has an internal protrusion 118 extending from the inner edge of the pump housing 110, the function of which will be described in detail below.

[0038] The turbomolecular pump 100 also includes a rotor 120 having a rotor shaft 122. The rotor shaft 122 further has a rotational shaft 124 about which the rotor 120 rotates during operation of the turbomolecular pump 100. This rotational shaft defines an axial direction within the turbomolecular pump 100, for example, in… Figure 1 From bottom to top. Therefore, the internal protrusion 118 of the pump casing extends inward in a radial direction perpendicular to the axial direction, and also extends circumferentially around the rotation axis 124 of the rotor 120.

[0039] Rotor 120 also includes rotor disk 126 associated with turbomolecular pump stage 102, and in Figure 1 The Hallwick rotor element 128 is arranged below the rotor disk 126 and extends downward in the axial direction.

[0040] Stator disks 132 are arranged between rotor disks 126 within the region of turbomolecular pump stage 102. Similarly, Hallwick pump stage 104 includes helical Hallwick stator elements 134, each associated with one of the Hallwick rotor elements 128.

[0041] The turbomolecular pump 100 also includes a bearing-drive unit or magnetically supported spindle 140, which includes bearing elements for supporting a magnetic bearing 141 for a rotor 120. The bearing elements of the magnetic bearing 141 include radial bearings 142 for supporting or aligning the rotor shaft 122 in a radial direction perpendicular to the rotation axis 124 or the axial direction. Furthermore, the bearing elements of the magnetic bearing 141 include axial bearings 144 for aligning or supporting the rotor shaft 122 in an axial direction parallel to the rotation axis 124. The radial bearing 142 and the axial bearing 144 of the magnetic bearing 141 are arranged within a bearing housing 146 of the bearing-drive unit 140. The bearing housing 146 has an external protrusion or flange 148 extending circumferentially around the rotation axis 124 at its outer edge for securing the bearing-drive unit 140 to an internal protrusion 118 of an intermediate member 114 by screws 149.

[0042] The bearing-drive unit 140 also includes an electric motor 150 for driving the rotor 120. Within the bearing-drive unit 140, the electric motor 150 is arranged axially between the radial bearings 142 of the magnetic bearing 141. The radial bearings 142 are generally identical in structure and are arranged opposite each other on both sides of the electric motor 150 when viewed axially. By distributing the radial bearings 142 of the magnetic bearing 141 on both sides of the electric motor 150, the vibration performance of the turbomolecular pump 100 is improved.

[0043] The rotor shaft 122 is driven to rotate by an electric motor 150. A gap 152 is formed between the rotor shaft 122 and the inner circumference of the bearing-drive unit 140, such that the rotor shaft 122 does not contact the bearing elements of the magnetic bearing 141 (i.e., the radial bearing 142 and the axial bearing 144) during operation of the turbomolecular pump 100. Instead, the rotor 120 is kept suspended by the magnetic bearing 141 during operation of the turbomolecular pump 100. For this purpose, the turbomolecular pump 100 has a position adjustment device (not shown). This position adjustment device adjusts the current in the magnetic coils of the radial bearing 142 and the axial bearing 144, thereby maintaining the spatial position of the rotor shaft 122 and the entire rotor 120 in a desired predetermined position. The magnetic bearing 141 is also referred to as an active magnetic bearing because it contains coils of electromagnets rather than permanent magnets.

[0044] The bearing-drive unit 140 also has a safety or thrust bearing 154 configured as a rolling bearing. When the turbomolecular pump 100 is shut down, the rotor shaft 122 contacts the thrust bearing 154. Furthermore, in the event of an unexpected event during turbomolecular pump operation, such as when the rotor 120 deviates significantly from its target position that should be maintained by the magnetic bearing 141 due to external influences, the rotor shaft 122 may also contact the thrust bearing 154.

[0045] The turbomolecular pump 100 is characterized in that the external protrusion or flange 148 of the bearing-drive unit or magnetic support spindle 140 is arranged axially within the region of the motor 150, and is fixedly connected to the internal protrusion 118 of the intermediate member 114 within this axial region of the motor 150 by screws 149, thereby forming a fixed connection with the pump housing 110. Therefore, this fixed connection is approximately equidistant from both the upper and lower axial ends of the bearing-drive unit 140. In other words, the fixed connection between the bearing-drive unit 140 and the pump housing 110 is located axially in the middle region of the bearing-drive unit or magnetic support spindle 140, rather than at one of its two axial ends.

[0046] By fixing the bearing-drive unit 140 in the middle region, a more rigid mechanical connection can be formed between the bearing-drive unit 140 and the pump housing 110 compared to arranging the corresponding fixing device at one of the two axial ends of the bearing-drive unit 140. This more rigid mechanical connection improves the vibration performance of the turbomolecular pump 100.

[0047] like Figure 1 As shown, the external protrusion or flange 148 is arranged adjacent to the motor 150 at the outer edge of the bearing-drive unit 140. Thus, the motor 150 and the external protrusion 148 of the bearing-drive unit 140 are in direct thermal contact. During operation of the turbomolecular pump 100, the bearing-drive unit 140 heats up primarily within the region of the motor 150. The heat generated by the motor 150 during operation of the turbomolecular pump 100 is dissipated directly and efficiently from the motor 150 to the pump housing 110 through the external protrusion 148 directly adjacent to the motor 150, and through the fixed connection between the external protrusion 148 of the bearing-drive unit 140 and the internal protrusion 118 of the intermediate member 114 or pump housing 110. Therefore, the arrangement of the external protrusion 148 of the bearing housing 146 in the intermediate region of the bearing-drive unit 140 and its direct proximity to the motor 150 improves the cooling performance of the motor 150 due to the improved heat dissipation during operation of the turbomolecular pump 100.

[0048] To further improve the cooling effect of the electric motor 150 during the operation of the turbomolecular pump 100, the intermediate component 114 has a first cooling element in the form of a cooling channel 156 through which cooling water flows, and therefore can also be referred to as a water cooling device 156. Figure 1 As shown, the distance between the water cooling device 156 and the motor 150 is relatively small, which results in efficient cooling of the motor 150. In addition, as a second cooling element, the intermediate component 114 also has a heat sink 158, which further enhances the cooling effect of the motor 150.

[0049] The turbomolecular pump 100 also includes a control unit 160, which has electrical connections (not shown) to the radial bearing 142, the axial bearing 144, and the electric motor 150. Since the fixed connection between the bearing-drive unit 140 and the pump housing 110 is located in the axially intermediate region of the bearing-drive unit in the form of an external protrusion 148, screws 149, and an internal protrusion 118 of the pump housing 110, there is a relatively large free space below the external protrusion 148 and therefore below the entire bearing-drive unit 140, in which wiring for the electrical connection between the bearing-drive unit 140 and the control unit 160 can be arranged. Due to this free space, the wiring of the bearing-drive unit 140 can be implemented efficiently without the risk of cables being caught.

[0050] Furthermore, the turbomolecular pump 100 has a position sensor 170, which is used to monitor the axial position of the rotor 120 during operation of the turbomolecular pump 100, and is configured as an eddy current sensor. Therefore, the position sensor 170 ensures that the rotor 120 is in the desired position in the axial direction and thus in a suspended state during operation of the turbomolecular pump 100.

[0051] When assembling the turbomolecular pump 100, if the turbomolecular pump 100 is as follows: Figure 1 In the vertical arrangement shown, the lower cover 180 is first removed to secure the bearing-drive unit or magnetic support spindle 140 to the turbomolecular pump 100 from below. The lower cover 180 is then connected to the lower portion 116 of the pump housing 110.

[0052] In an alternative embodiment of the turbomolecular pump (not shown), the external protrusion 148 of the bearing-drive unit 140 and the internal protrusion 118 of the intermediate member 114 are interchangeable in the axial direction, such that the external protrusion 148 of the bearing-drive unit 140 is positioned above the internal protrusion 118 of the intermediate member 114 or the pump housing 110 in the axial direction. However, in this alternative embodiment, the bearing-drive unit 140 is inserted into the turbomolecular pump 100 from above, i.e., from one side of the pumping elements 126, 128.

[0053] In this embodiment, the bearing-drive unit 140 can be assembled together with the rotor 120 and balanced, for example, by laser dynamic balancing, before the rotor 120 and the assembly of the magnetic support spindle or bearing-drive unit 140 are inserted into the pump housing 110 from above. This simplifies the balancing process of the turbomolecular pump 100 because the bearing-drive unit or magnetic support spindle 140 and the rotor 120 are already balanced before being inserted into the pump housing 110.

[0054] In this embodiment, the external protrusion 148 of the bearing housing 146 may also have a receiving element for the Hallwick stator element 134. This allows for smaller tolerances between the Hallwick stator element 134 and the rotor 120, i.e., between the Hallwick stator element 134 and the Hallwick rotor element 128.

[0055] In another alternative embodiment, also not shown, the fixed connection between the bearing-drive unit 140 and the pump housing 110 can be achieved by a press-fit or retraction fit rather than by a screw 149. Furthermore, the bearing housing may alternatively have external threads that can be screwed into a portion of the intermediate piece 114 and thus into the internal threads of the pump housing 110. Additionally, the external protrusion 148 of the bearing-drive unit or magnetic support spindle 140 may be configured to replace the intermediate piece 114 between the upper and lower portions 112 and 116 of the pump housing.

[0056] List of reference numerals 100 Vacuum pump or turbomolecular pump 102 Turbomolecular Pump Stage 104 Holwick pump stage 110 Pump casing 112 Upper part of pump casing 114 Pump casing intermediate parts 116 Lower part of pump casing 118 Internal protrusions of intermediate components 120 rotor 122 Rotor Shaft 124 Rotating Axis 126 Rotor Disc 128 Hallwick rotor elements 132 stator plate 134 Hallwick stator elements 140 Bearing-Drive Unit or Magnetic Support Spindle 141 Active magnetic bearing 142 Radial bearing 144 Axial Bearing 146 Bearing Housing 148 External protrusion of bearing housing 149 screws 150 electric motor 152. Clearance between rotor shaft and magnetic bearing 154 Safety or thrust bearing 156 Water cooling device 158 heatsink 160 Control Unit 170 Position Sensor 180 bottom cover

Claims

1. A vacuum pump (100), particularly a turbomolecular pump, said vacuum pump (100) comprising: Pump casing (110). The rotor (120) includes pumping elements (126, 128) and has a rotating shaft (124) that defines the axial direction. Bearing-drive unit (140), the bearing-drive unit (140) includes: Bearing elements (142, 144) are used to support the magnetic bearing (141) of the rotor (120). Motor (150), said motor (150) for driving said rotor (120), and The bearing housing (146), the bearing elements (142, 144), and the rotor (120) are arranged within the bearing housing (146). The bearing housing (146) has fixed connections (118, 148, 149) with the pump housing (110), and the fixed connections are arranged in the region of the motor (150) in the axial direction.

2. The vacuum pump (100) according to claim 1, wherein The fixed connection (118, 148, 149) of the bearing housing (146) is formed by a portion of the pump housing (110), which has at least one cooling element (156, 158).

3. The vacuum pump (100) according to claim 2, wherein The cooling elements (156, 158) are configured as water cooling devices (156).

4. The vacuum pump (100) according to claim 3, wherein A portion of the water cooling device (156) extends through the bearing-drive unit (140).

5. The vacuum pump (100) according to any one of claims 2 to 4, wherein The portion of the pump housing (110) that forms the fixed connection (118, 148, 149) with the bearing housing (146) has a heat sink (158).

6. The vacuum pump (100) according to any one of claims 1 to 5, wherein The bearing housing (146) has an external protrusion (148) that extends outward from the outer edge of the bearing housing (146) in a radial direction perpendicular to the axial direction. The pump housing (110) has an internal protrusion (118) that extends inwardly from the inner edge of the pump housing (110) in the radial direction, and The fixed connection (118, 148, 149) between the bearing housing (146) and the pump housing (110) is formed by the connection of the external protrusion (148) of the bearing housing (146) and the internal protrusion (118) of the pump housing (110).

7. The vacuum pump (100) according to claim 6, wherein The internal protrusion (118) of the pump housing (110) is arranged in the axial direction between the external protrusion (148) of the bearing housing (146) and the pumping elements (126, 128) of the rotor (120).

8. The vacuum pump (100) according to claim 6, wherein The external protrusion (148) of the bearing housing (146) is arranged in the axial direction between the internal protrusion (118) of the pump housing (110) and the pumping elements (126, 128) of the rotor (120).

9. The vacuum pump (100) according to claim 8, wherein The bearing-drive unit (140) has a housing element for securing the stator element (134) of one or more pump stages (104) of the vacuum pump (100).

10. The vacuum pump (100) according to claim 7, wherein The fixed connections (118, 148, 149) include a threaded connection (149) that extends through the external protrusion (148) of the bearing housing (146) toward the pumping element (126, 128).

11. The vacuum pump (100) according to claim 8 or 9, wherein The fixed connections (118, 148, 149) include threaded connections that extend through the internal protrusion (118) of the pump housing (110) toward the pumping elements (126, 128).

12. The vacuum pump (100) according to any one of claims 1 to 9, wherein The fixed connections (118, 148, 149) are formed by pressing or retracting the bearing housing (146) into a portion of the pump housing (110).

13. The vacuum pump (100) according to any one of claims 1 to 9, wherein The bearing housing (146) has an external thread that is designed to screw into the internal thread of a portion of the pump housing (110).

14. The vacuum pump (100) according to any one of claims 1 to 5, wherein The bearing housing (146) has an external protrusion (148) that extends from the outer edge of the bearing housing (146) in a radial direction perpendicular to the axial direction, and The external protrusion (148) of the bearing housing (146) forms part of the pump housing (110).

15. The vacuum pump (100) according to any one of claims 1 to 14, wherein The motor (150) is arranged in the axial direction between the bearing elements (142, 144) of the magnetic bearing (141).

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