Vacuum pump, scroll pump and method of manufacturing same

Abstract

The invention relates, among other things, to a vacuum pump, in particular a scroll pump, with an electronics housing in which one or more electronic components are arranged, wherein a separate chamber is provided within the electronics housing for at least one electronic component, in which the electronic component is encapsulated.

Description

[0001] The present invention relates to a vacuum system with a high vacuum pump and a backing pump designed as a scroll pump.

[0002] A vacuum system with a high-vacuum pump and a backing pump is disclosed in EP 3 067 560 A1. Further prior art includes US 9 341 187 B2, US 2014 / 219846 A1, EP 1 918 585 A2, and JP 2003 120529 A.

[0003] It is an object of the invention to simplify the use of a scroll pump in a vacuum system. This object is achieved by a vacuum system according to claim 1 and, in particular, by the pump comprising an integrated pressure sensor.

[0004] A vacuum system usually already includes a pressure sensor, for example, in a vacuum chamber. By integrating the pressure sensor into the scroll pump, it can now operate largely independently and without a complex connection to the vacuum system's pressure sensor. Conversely, an additional pressure sensor in the vacuum system can be eliminated, for example. In general, the integrated pressure sensor allows the scroll pump to monitor itself, eliminating the need for complex monitoring by a process control system. In particular, pump wear can be monitored based on a measured pressure.

[0005] According to the invention, the pressure sensor is integrated into a control system of the vacuum system.

[0006] In the case envisaged by the invention, where the scroll pump is used as a backing pump for a high-vacuum pump, the integrated pressure sensor can also ensure increased operational reliability. If the pressure in the scroll pump becomes too high, the high-vacuum pump is shut down and / or intermediate valves are closed. The high-vacuum pump can thus be reliably protected from operation at excessive pressure.

[0007] Preferably, the pressure sensor can also be integrated into a scroll pump control system. This allows the scroll pump to be more effectively controlled and regulated based on the now known pressure in the scroll pump.

[0008] According to one embodiment, the pressure sensor is designed to measure a suction pressure of the pump or a pressure between two pump-active spiral walls or between two spiral walls in a pump-active spiral section. Both enable even more precise monitoring of the pumping process and the wear condition of the pump, in particular of a sealing element, such as a tip seal, or of the spiral walls.

[0009] In a further advantageous embodiment, the pressure sensor is screwed into a component of the scroll pump. This enables both a simple design and flexible distribution of the scroll pump. Instead of the integrated pressure sensor, a blind plug can be provided, for example, if an integrated pressure sensor is not absolutely necessary for the user's process. Nevertheless, in this case, an integrated pressure sensor can be easily retrofitted. The component into which the pressure sensor is screwed can, for example, be a housing element and / or a fixed spiral component. In particular, the pressure sensor can be screwed axially into a fixed spiral component.

[0010] According to a further development, the pressure sensor can be arranged in a cooling air flow of a cooling device, for example, a fan of the pump. The pressure sensor can thus be directly cooled in an advantageous manner, which improves its service life and measurement accuracy. Preferably, the pressure sensor can be arranged at least substantially at the beginning of the cooling air flow, namely adjacent to a fan and / or within an air guide hood.

[0011] In principle, for example, several pressure sensors can be integrated into the scroll pump. This can further improve control and wear monitoring.

[0012] The invention is explained below merely by way of example with reference to the schematic drawing. Fig. 1 shows a scroll pump in a sectional view. Fig. 2 shows an electronics housing of the scroll pump. Fig. 3 shows the scroll pump in a perspective view, with selected elements cut out. Fig. 4 shows a pressure sensor integrated into the pump. Fig. 5 shows a movable spiral component of the pump. Fig. 6 shows the spiral component of another, Fig. 5 visible side opposite side. Fig. 7 shows a clamping device for a spiral component. Figs. 8 and 9 each show an eccentric shaft with a counterweight of different scroll pumps. Fig. 10 shows a gas ballast valve with an operating handle in perspective view. Fig. 11 shows the valve of the Fig. 10 in a sectional view. Fig. 12 shows a portion of the spiral component of the Fig. 5 und 6 . Fig. 13 shows a cross-section of the spiral component through the spiral wall in an outer end area. Fig. 14 shows an air guide hood of the scroll pump of the Fig. 1 in perspective view. Fig. 15 shows a sectional view of a forcing thread.

[0013] The Fig. 1 shows a vacuum pump designed as a scroll pump 20. This comprises a first housing element 22 and a second housing element 24, wherein the second housing element 24 has a pumping-active structure, namely a spiral wall 26. The second housing element 24 thus forms a stationary spiral component of the scroll pump 20. The spiral wall 26 interacts with a spiral wall 28 of a movable spiral component 30, wherein the movable spiral component 30 is eccentrically excited via an eccentric shaft 32 to generate a pumping effect. A gas to be pumped is conveyed from an inlet 31, which is defined in the first housing element 22, to an outlet 33, which is defined in the second housing element 24.

[0014] The eccentric shaft 32 is driven by a motor 34 and supported by two roller bearings 36. It comprises an eccentric pin 38 arranged eccentrically to its rotational axis, which transmits its eccentric deflection to the movable spiral component 30 via a further roller bearing 40. For sealing purposes, a Fig. 1 left-hand end of a bellows 42, the right-hand end of which is attached to the first housing element 22. The left-hand end of the bellows 42 follows the deflection of the movable spiral component 30.

[0015] The scroll pump 20 includes a fan 44 for generating a cooling air flow. An air guide hood 46 is provided for this cooling air flow, to which the fan 44 is also attached. The air guide hood 46 and the housing elements 22 and 24 are shaped such that the cooling air flow essentially surrounds the entire pump housing, thus achieving good cooling performance.

[0016] The scroll pump 20 further comprises an electronics housing 48, in which a control device and power electronics components for driving the motor 34 are arranged. The electronics housing 48 also forms a base for the pump 20. Between the electronics housing 48 and the first housing element 22, a channel 50 is visible, through which an air flow generated by the fan 44 is guided along the first housing element 22 and also along the electronics housing 48, so that both are effectively cooled.

[0017] The electronics housing 48 is in Fig. 2 illustrated in more detail. It comprises a plurality of separate chambers 52. Electronic components can be encapsulated in these chambers 52 and are thus advantageously shielded. Preferably, the smallest possible amount of encapsulation material can be used when encapsulating the electronic components. For example, the encapsulation material can first be introduced into the chamber 52 and then the electronic component can be pressed in. Preferably, the chambers 52 can be designed such that different variants of the electronic components, in particular different assembly variants of a circuit board, can be arranged and / or encapsulated in the electronics housing 48. For certain variants, individual chambers 52 can also remain empty, i.e. have no electronic component. In this way, a so-called modular system for different pump types can be implemented in a simple manner.The potting material can in particular be thermally conductive and / or electrically insulating.

[0018] At a related Fig. 2 Formed on the rear side of the electronics housing 48 are a plurality of walls or ribs 54, which define a plurality of channels 50 for conducting a cooling air flow. The chambers 52 also enable particularly good heat dissipation from the electronic components arranged therein, particularly in conjunction with a thermally conductive encapsulation material, and toward the ribs 54. The electronic components can thus be cooled particularly effectively, and their service life is improved.

[0019] In Fig. 3 the scroll pump 20 is shown in perspective as a whole, but with the air guide hood 46 hidden so that in particular the fixed spiral component 24 and the fan 44 are visible. On the fixed spiral component 24, a plurality of recesses 56 arranged in a star shape are provided, each of which defines ribs 58 arranged between the recesses 56. The cooling air flow generated by the fan 44 leads through the recesses 56 and past the ribs 58 and thus cools the fixed spiral component 24 particularly effectively. The cooling air flow first flows around the fixed spiral component 24 and only then the first housing element 22 or the electronics housing 48. This arrangement is particularly advantageous because the pump-active region of the pump 20 develops a high level of heat due to the compression during operation and is therefore primarily cooled here.

[0020] The pump 20 includes an integrated pressure sensor 60. This is arranged within the air guide hood 46 and screwed into the fixed spiral component 24. The pressure sensor 60 is connected via a cable connection (only partially shown) to the electronics housing 48 and a control device arranged therein. The pressure sensor 60 is integrated into the control system of the scroll pump 20. For example, the motor 34, which is Fig. 1 visible, depending on a pressure measured by pressure sensor 60. For example, when using pump 20 in a vacuum system as a backing pump for a high-vacuum pump, the high-vacuum pump can only be switched on if pressure sensor 60 measures a sufficiently low pressure. This protects the high-vacuum pump from damage.

[0021] Fig. 4 shows the pressure sensor 60 and its arrangement on the stationary spiral component 24 in a cross-sectional view. A channel 62 is provided for the pressure sensor 60, which here opens into a non-pumping-active outer region between the spiral walls 26 and 28 of the stationary and movable spiral components 24 and 30, respectively. Thus, the pressure sensor measures a suction pressure of the pump. Alternatively or additionally, a pressure between the spiral walls 26 and 28 in a pumping-active region can also be measured. Depending on the position of the pressure sensor 60 or the channel 62, intermediate pressures can also be measured, for example.

[0022] The pressure sensor 60 allows, for example by determining compression, in particular the detection of a wear condition of the pump-active components, in particular of a sealing element 64 also referred to as a tip seal. Furthermore, the measured suction pressure can also be used to control the pump (including the pump speed). For example, a suction pressure can be specified via software and a suction pressure can be set by varying the pump speed. It is also conceivable that, depending on the measured pressure, a pressure increase due to wear can be compensated for by increasing the speed. In this way, a tip seal change can be postponed or longer change intervals can be implemented. The data from the pressure sensor 60 can therefore generally be used, for example, to determine wear, to control the pump in a given situation, for process control, etc.

[0023] The pressure sensor 60 can be provided optionally, for example. Instead of the pressure sensor 60, a blind plug can be provided to close the channel 62. A pressure sensor 60 can then be retrofitted, for example, if necessary. Particularly with regard to retrofitting, but also generally advantageous, it can be provided that the pressure sensor 60 is automatically recognized when connected to the control device of the pump 20.

[0024] The pressure sensor 60 is arranged in the cooling air stream of the fan 44. This also advantageously cools it. This also means that no special measures are required to increase the temperature resistance of the pressure sensor 60, allowing a more cost-effective sensor to be used.

[0025] In addition, the pressure sensor 60 is arranged in particular in such a way that the external dimensions of the pump 20 are not increased by it and the pump 20 consequently remains compact.

[0026] In the Fig. 5 und 6 The movable spiral component 30 is shown in different views. In Fig. 5 The spiral structure of the spiral wall 28 is particularly clearly visible. In addition to the spiral wall 28, the spiral component 30 includes a base plate 66 from which the spiral wall 28 extends.

[0027] A side of the base plate 66 facing away from the spiral wall 28 is in Fig. 6 visible. On this side, the base plate includes, among other things, several

[0028] Mounting recesses, for example for mounting the bearing 40 and the bellows 42, which are Fig. 1 are visible.

[0029] On the outside of the base plate 66, three retaining projections 68 are provided, spaced apart and evenly distributed over the circumference of the base plate 66. The retaining projections 68 extend radially outward. In particular, the retaining projections 68 all have the same radial height.

[0030] A first intermediate section 70 of the circumference of the base plate 66 extends between two of the retaining projections 68. This first intermediate section 70 has a greater radial height than a second intermediate section 72 and a third intermediate section 74. The first intermediate section 70 is arranged opposite an outermost 120° section of the spiral wall 28.

[0031] During the manufacture of the movable spiral component 30, the base plate 66 and the spiral wall 28 are preferably manufactured jointly from a solid material, ie the spiral wall 28 and the base plate 66 are formed in one piece.

[0032] For example, during finishing operations, the spiral component 30 can be clamped directly to the holding projections 68. Within the scope of one and the same clamping, for example, the Fig. 6 The side of the base plate 66 shown is machined, in particular the fastening recesses are created. In principle, the spiral wall 28 can also be machined from solid material within the scope of this clamping.

[0033] For this purpose, the spiral component 30 can be clamped, for example, with a clamping device 76 as shown in Fig. 7 This has a hydraulic three-jaw chuck 78 for direct engagement with the three retaining projections 68. In addition, the clamping device 76 has a continuous recess 80 through which a tool access to the spiral component 30, in particular to the Fig. 6 shown side thereof. Thus, machining operations can be carried out from both sides during clamping, in particular at least a finishing operation of the spiral wall 28 and the introduction of fastening recesses.

[0034] The contour of the retaining projections 68 and the clamping pressure of the clamping device 76 are preferably selected such that no critical deformations of the spiral component 30 occur. The three retaining projections 68 are preferably selected such that the outer dimension, i.e., the maximum diameter of the spiral component 30, is not increased. This allows for savings in material and machining volume. The retaining projections 68 are, in particular, designed and / or arranged at such an angular position that the screw connection of the corrugated bellows 42 is accessible. The number of screw connection points of the corrugated bellows 42 is preferably different from the number of retaining projections 68 on the movable spiral component 30.

[0035] On the eccentric shaft 32 of the Fig. 1 Two balancing weights 82 are mounted to compensate for any imbalance in the excited system. The area of ​​the Fig. 1 right-hand balance weight 82 is in Fig. 8 Enlarged image. The counterweight 82 is screwed to the eccentric shaft 32.

[0036] A similar image section is in Fig. 9 shown for another scroll pump, which preferably belongs to the same series as pump 20 of the Fig. 1 The Fig. 9 The underlying pump has different dimensions and therefore requires a different balancing weight 82.

[0037] The eccentric shafts 32, the counterweights 82 and the housing elements 22 are dimensioned such that only one specific type of the two types of counterweights 82 shown can be mounted on the eccentric shaft 32 at the respective mounting position shown.

[0038] The balancing weights 82 are in the Fig. 8 und 9 together with certain dimensions of the installation space provided for them, to clarify that the counterweight 82 of the Fig. 9 cannot be mounted on the eccentric shaft 32 and vice versa. It is understood that the dimensions given are purely exemplary.

[0039] In Fig. 8 a distance between a mounting hole 84 and a shaft shoulder 86 9.7 mm. The counterweight 82 of the Fig. 8 is shorter in the corresponding direction, namely 9 mm long, and can therefore be installed without any problems. The counterweight 82 of the Fig. 9 has a longitudinal extension of 11 mm measured from the mounting hole. Thus, the counterweight 82 of the Fig. 9 not on the eccentric shaft 32 of the Fig. 8 cannot be mounted, since the shaft shoulder 86 collides with the counterweight 82 during an attempted mounting or since the counterweight 82 of the Fig. 9 not fully aligned with the eccentric shaft 82 of the Fig. 8 Because the balance weight 82 of the Fig. 9 in both dimensions is greater than the distance between the fastening hole 84 and the shaft shoulder 86 in Fig. 8 , also prevents installation in the reverse direction. In addition, the dimension of 21.3 mm of the counterweight 82 of the Fig. 8 an inverted and consequently incorrect mounting orientation of the otherwise correct counterweight 82.

[0040] In Fig. 9 The distance in the longitudinal direction between the mounting hole 84 and a housing shoulder 88 is 17.5 mm. The counterweight 82 of the Fig. 8 With its extension of 21.3 mm, when inserting the eccentric shaft 32, the Fig. 9 collide with the housing shoulder 88, so that complete assembly would not be possible. Incorrect assembly is possible at first, but is reliably detected. If the counterweight 82 of the Fig. 8 on the eccentric shaft 32 of the Fig. 9 the extension of 21.3 mm would collide with the shaft shoulder 86, which is arranged only at a distance of 13.7 mm from the fastening bore 84.

[0041] The counterweights 82, in particular a motor-side counterweight 82, are generally designed to prevent confusion of the counterweight with those of other sizes during assembly and / or servicing. The counterweights are preferably attached using through-bolts. Similar counterweights of different pump sizes are particularly designed to prevent installation of the wrong counterweight due to adjacent shoulders on the shaft, the positions of the thread and through-hole of the counterweight, and shoulders within the housing.

[0042] In the Fig. 10 und 11 A gas ballast valve 90 of the scroll pump 20 is shown. This is also shown in the overall view of the pump 20 in Fig. 3 visible and arranged on the fixed spiral component 24.

[0043] The gas ballast valve 90 comprises an actuating handle 92. This comprises a plastic body 94 and a base element 96, which is preferably made of stainless steel. The base element 96 comprises a through-bore 98, which is provided on the one hand for connecting and introducing a ballast gas and on the other hand comprises a check valve 100. The bore 98 is also closed in the illustrations by means of a plug 102. Instead of the plug 102, a filter can also be provided, for example, wherein the ballast gas can preferably be air and enters the valve 90 directly via the filter. The actuating handle 92 is fastened to a rotatable element 106 of the valve 90 by means of three fastening screws 104, which are arranged in a respective bore 108 and of which, in the selected sectional view, the Fig. 11 only one is visible. The rotatable element 106 is rotatably attached to the second housing element 24 by a fastening screw (not shown) extending through a bore 110.

[0044] To actuate the valve 90, a torque applied manually to the actuating handle 92 is transmitted to the rotatable element 106, thus rotating it. Thus, the bore 98 comes into communication with the interior of the housing. Three switching positions are provided for the valve 90, namely the Fig. 10 shown, which is a locking position, and a position rotated to the right and to the left, in which the bore 98 is in communication with different areas of the interior of the housing.

[0045] Bores 108 and 110 are closed by a cover 112. The sealing effect of the gas ballast valve 90 is based on axially compressed O-rings. When the valve 90 is actuated, a relative movement is exerted on the O-rings. If contaminants, such as particles, reach the surface of an O-ring, this poses the risk of premature failure. The cover 112 prevents contaminants and the like from penetrating the screws of the handle 92.

[0046] This cover 112 is secured via an interference fit of three centering elements. Specifically, the cover 112 has a pin (not shown) for each bore 108, which secures the cover 112 in the bores 108. The bores 108 and 110, as well as the fastening screws arranged therein, are thus protected from contamination. In particular, the fastening screw (not shown) arranged in the bore 110, which allows rotation, effectively minimizes the ingress of contamination into the valve mechanism, thus improving the service life of the valve.

[0047] The plastic handle with an overmolded stainless steel base ensures good corrosion resistance while keeping manufacturing costs low. Furthermore, the plastic handle stays cooler due to limited heat conduction, making it easier to use.

[0048] For the fan 44, as used for example in the Fig. 1 and 3 visible, a speed control is preferably provided. The fan is controlled by means of PWM depending on the power consumption and temperature of the power module which is housed, for example, in the electronics housing 48. The speed is set analogously to the power consumption. However, control is only permitted above a module temperature of 50 °C. If the pump enters temperature ranges of possible derating (temperature-related power reduction), the max. fan speed is automatically controlled. This control ensures that a minimum noise level is achieved when the pump is cold, that a low noise level - corresponding to the pump noise - prevails at ultimate pressure or at low load, that optimal cooling of the pump is achieved with a low noise level at the same time, and that the maximum cooling capacity is ensured before a temperature-related power reduction.

[0049] The maximum fan speed can be adjusted, especially depending on the situation. For example, it may be beneficial to reduce the maximum fan speed to ensure high water vapor tolerance.

[0050] In Fig. 12 the movable spiral component 30 is partially and opposite Fig. 5 enlarged. A sectional view of the spiral component 30 along the Fig. 12 indicated line A:A is in Fig. 13 shown schematically and not to scale.

[0051] The spiral wall 28 has, at its end facing away from the base plate 66 and towards a base plate of the fixed spiral component 24 (not shown here), a groove 114 for the insertion of a sealing element 64 (also not shown here), namely a so-called tip seal. The arrangement in the operating state is shown, for example, in Fig. 4 clearly visible.

[0052] The groove 114 is delimited outwardly and inwardly by two opposite side walls, namely an inner side wall 116 and an outer side wall 118. In a first spiral section 120, the outer side wall 118 is thicker than the inner side wall 116 in the first spiral section 120 and thicker than both side walls 116 and 118 in another, second spiral section 122.

[0053] The first spiral section 120 extends from Fig. 12 indicated place to the outer end of the spiral wall 28, as is also the case in Fig. 5 is indicated. The first spiral section 120 extends here, for example, over approximately 163°.

[0054] The first spiral section 120 forms an outer end section of the spiral wall 28. The first spiral section 120 is arranged at least partially, in particular completely, in a non-pumping-active region of the spiral wall 28. In particular, the first spiral section 120 can at least substantially completely fill the non-pumping-active region of the spiral wall 28.

[0055] As it is in Fig. 5 As can be seen, the first intermediate section 70, which has a greater radial height than other intermediate sections 72 and 74, can preferably be arranged opposite the first spiral section 120 between two retaining projections 68. An imbalance introduced by the thicker side wall 118 can thus be compensated for by the greater weight of the first intermediate section 70.

[0056] To keep the system load on the bearings and other components low, the moving scroll component should generally have a low dead weight. For this reason, the scroll walls are generally very thin. Furthermore, thinner walls result in smaller pump dimensions (significant outer diameter). The side walls of the tip seal groove are therefore particularly thin. The ratio of the tip seal wall thickness to the total scroll wall thickness is, for example, a maximum of 0.17. However, due to the tip seal groove, the scroll wall tip is very sensitive to impacts during handling, such as during assembly or when changing the tip seal. Slight impacts, e.g. during transport, can push the side wall of the groove inwards, making it impossible to install the tip seal. To solve this problem, the groove has an asymmetrical wall thickness, in particular a local thickening of the scroll wall towards the outside.This area is preferably not pump-active and can therefore be manufactured with a larger tolerance. The one-sided thickening on the coil, especially the last half, significantly reduces damage. At other parts of the component, thickening of the spiral wall is preferably not necessary, as the wall is protected by protruding elements of the component.

[0057] The Fig. 1 The air guide hood 46 shown defines an air flow, as indicated by a dashed arrow 124. The fan 44 is connected to a control device in the electronics housing 48 via a cable (not shown) that runs through the air guide hood 46, and via a plug connection. This comprises a socket 126 and a plug 128. The socket 126 is mounted on the electronics housing 48 and / or attached to a circuit board arranged in the electronics housing 48. The socket 126 is also shown, for example, in the Fig. 2 and3 visible. Connector 128 is connected to fan 44 via a cable not shown.

[0058] The plug connection 126, 128 is separated from the air flow 124 by a partition 130. The air flow 124, which may contain, for example, dust or similar contaminants, is thus kept away from the plug connection 126, 128. This protects the plug connection 126, 128 itself, while preventing contaminants from entering the electronics housing 48 through the opening provided for the socket 126 and reaching the control device and / or power electronics.

[0059] The air guide hood 46 is in Fig. 14 shown separately and in perspective. Visible, among other things, is the partition 130 with the space defined behind it for the connector 128. The partition 130 includes a recess 132, designed here as a V-shaped notch, for passing a cable from the connector 128 to the fan 44.

[0060] For example, to save costs, inexpensive connectors without sealing (e.g., no IP protection) can be used, since the partition 130 ensures that the sucked-in air does not reach the electronics via the opening in the connector 126, 128. The fan cable is guided laterally through the partition 130 through the V-shaped notch 132. The notch 132 is laterally offset from the connector 126, 128, creating a labyrinth effect and thus further reducing the leakage of cooling air to the connector 126, 128. A partition 130 within the air guide hood 46 also improves the air flow into the channel 50 between the electronics housing 48 and the pump housing 22. This creates less turbulence and backpressure for the fan 44.

[0061] The Fig. 15 shows a contact area between the first housing element 22 and the second housing element or stationary spiral component 24 in a schematic sectional view. The second housing element 24 is partially inserted into the first housing element 22 with a transition fit 134. Sealing is provided by an O-ring 136. The transition fit 134 also serves, for example, to center the second housing element 24 relative to the first housing element 22.

[0062] For maintenance purposes, for example to replace the sealing element 64, the second housing element 24 must be disassembled. In doing so, the transition fit 134 or the O-ring 136 may jam if the second housing element 24 is not pulled out straight enough. To solve this problem, a forcing thread 138 is provided. Preferably, a second forcing thread can also be provided, at least substantially radially opposite. To release the second housing element 24 as straight and guided as possible, a screw can be screwed into the forcing thread 38 until the screw protrudes from it and comes into contact with the first housing element 22. By screwing it in further, the housing elements 22 and 24 are pressed away from one another.

[0063] For example, the fastening screws 142 provided for fastening the second housing element 24 to the first housing element 22 can be used for pressing, as they are shown, for example, in the Fig. 1 and 3 For this purpose, the forcing thread 138 preferably has the same thread type as the fastening threads provided for the fastening screws 142.

[0064] A countersink 140 is provided on the second housing element 22, which is associated with the forcing thread 138. If abrasion particles are discharged when screwing the screw into the forcing thread 138, they collect in the countersink 140. This prevents such abrasion particles from, for example, preventing the housing elements 22 and 24 from fully engaging one another.

[0065] When assembling the fixed spiral component 24, the screws must be removed again, as otherwise a complete screwing (correct fit on the flat surface of the housing) of the fixed spiral component 24 to the first housing element 22 may be prevented. Leakage, misalignment and a reduction in pump performance may result. To avoid this assembly error, the air guide hood 46 has at least one, in particular additional, Fig. 14 The dome 144 shown here only allows the air guide hood 46 to be mounted if the screws used for forcing, in particular the fastening screws 142, have been removed. This is because the air guide hood 46 with the dome 144 is designed in such a way that it would collide with the screw head of any forcing screw screwed into the forcing thread 138, so that the air guide hood 46 would not be fully mountable. In particular, the air guide hood 46 can only be mounted if the forcing screws are completely removed. Bezugszeichenliste

[0066] 20Scroll pump 22First housing element 24Second housing element / stationary scroll component 26Scroll wall 28Scroll wall 30Movable scroll component 32Eccentric shaft 34Motor 36Rolling bearing 38Eccentric pin 40Rolling bearing 42Bellows 44Fan 46Air guide hood 48Electronics housing 50Channel 52Channel 54Rib 56Recess 58Rib 60Pressure sensor 62Channel 64Seal element 66Base plate 68Retaining projection 70First intermediate section 72Second intermediate section 74Third intermediate section 76Clamping device 78Three-jaw chuck 80Recess 82Counterweight 84Mounting hole 86Shaft shoulder 88Housing shoulder 90Gas ballast valve 92Operating handle 94Plastic body 96Base element 98Bore 100Check valve 102Plug 104Fastening screw 106Rotatable element 108Bore 110Bore 112Cover 114Groove 116Inner side wall 118Outer side wall 120First spiral section 122Second spiral section 124Air flow 126Socket 128Plug 130Partition 132Recess 134Transition fit 136O-ring 138Forcing thread140Countersink 142Fastening screw 144Dom

Claims

1. A vacuum system comprising a high-vacuum pump; a vacuum pump, namely a scroll pump (20), which is provided as a roughing pump for a high-vacuum pump; and a control, wherein the scroll pump comprises a pressure sensor (60) integrated into the scroll pump (20), characterized in that the pressure sensor (60) is integrated into the control of the vacuum system; and in that the control is configured to switch off the high-vacuum pump and / or to close interposed valves at too high a pressure in the scroll pump.

2. A vacuum system in accordance with claim 1, wherein the pressure sensor (60) is also integrated into a control of the scroll pump (20).

3. A vacuum system in accordance with at least one of the preceding claims, wherein the pressure sensor (60) is provided for measuring a suction pressure of the scroll pump (20).

4. A vacuum system in accordance with claim 1 or 2, wherein the pressure sensor (60) is provided for measuring a pressure between two pump-active spiral walls (26, 28).

5. A vacuum system in accordance with at least one of the preceding claims, wherein the pressure sensor (60) is screwed into a component (24) of the scroll pump (20).

6. A vacuum system in accordance with at least one of the preceding claims, wherein the pressure sensor (60) is arranged in a cooling air flow of a cooling device (44) of the scroll pump (20).

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