Scroll vacuum pump and scroll vacuum pump system

Abstract

A scroll vacuum pump includes a pump system; a drive shaft that has an eccentric section for driving the pump system; and an electric drive motor for the drive shaft. At least two support points spaced apart from one another along the axis of rotation of the drive shaft are provided for the rotational support of the drive shaft. All the support points are located on the side of the drive motor facing the eccentric section of the drive shaft and / or between a front balancing weight and a rear balancing weight of the drive shaft

Description

[0001] The present disclosure relates to the improvement of scroll vacuum pumps and of scroll vacuum pump systems comprising a plurality of scroll vacuum pumps of different designs.

[0002] In this respect, the scroll vacuum pumps each comprise a pump system that comprises a stationary spiral component and a movable spiral component cooperating with said stationary spiral component in a pump-active manner; a drive shaft that rotates about an axis of rotation during operation and that has an eccentric section for driving the movable spiral component; and an electric drive motor for the drive shaft.

[0003] Scroll vacuum pumps are generally known, e.g. from EP 3 153 708A2 , EP 3 617 511 A2 and EP 3 647 599A2 .

[0004] A scroll vacuum pump is a displacement pump that compresses against atmospheric pressure and that can be used as a compressor, among other things. A scroll vacuum pump can be used to generate a vacuum in a recipient that is connected to a gas inlet of the scroll vacuum pump.

[0005] Scroll vacuum pumps are also called spiral vacuum pumps or spiral conveying devices. The underlying pumping principle of a scroll vacuum pump is generally known from the prior art and is therefore explained briefly below.

[0006] The pump system of a scroll vacuum pump has two spiral cylinders that are nested or inserted into another, for example Archimedean spiral cylinders, that are also simply referred to as spirals. Each spiral cylinder in this respect comprises at least one equidistant spiral wall having a support, in particular a plate-shaped support, provided at an end face of the spiral wall, wherein the outer windings of the spiral cylinder, for example the two or three outermost windings of the spiral cylinder, can be formed by wall sections that each have a constant spacing from the center of the spirals in the peripheral direction. Even if, strictly speaking, these wall sections do not form spiral sections but rather circular sections, they are attributed to the spiral in the context of the present disclosure and are referred to as windings of the spiral.

[0007] The spiral cylinders are in this respect inserted into one another such that the two spiral cylinders sectionally enclose crescent-shaped or sickle-shaped volumes. One of the two spirals is in this respect arranged in an unmovable or stationary manner in the housing of the pump, whereas the other spiral together with its support can be moved on a circular path via the eccentric section of the drive shaft so that this spiral together with its support is also called an orbiter. This movable spiral component thus performs a so-called centrally symmetrical oscillation, which is also called “orbiting” or “wobbling”. A crescent-shaped volume enclosed between the spiral cylinders continues to migrate increasingly inwardly within the spirals during the orbiting of the movable spiral component, whereby, by means of the migrating volume, the process gas to be pumped is conveyed radially inwardly from a radially outwardly disposed gas inlet of the pump system to a gas outlet of the pump system that is in particular located at the spiral center.

[0008] The eccentric drive, i.e. the drive shaft having the eccentric section, is located within the housing of the scroll vacuum pump at the side of the support facing away from the spiral of the orbiter and in practice is usually surrounded by a deformable sleeve, for example a corrugated bellows, that serves, on the one hand, to seal the drive against the suction region and, on the other hand, serves as a security against rotation for the orbiter since the orbiter could otherwise, i.e. without a security against rotation, rotate about itself. To ensure this security against rotation, the deformable sleeve can, for example, be connected to the support at a first end, whereas the second end of the deformable sleeve disposed opposite the first end can be screwed to a housing base by means of a plurality of fastening means in the interior of the housing.

[0009] Within the framework of the pump installation, the assembly comprising the orbiter and the deformable sleeve (e.g. corrugated bellows) can be pre-assembled so that this assembly can then be inserted as a unit into the pump housing, whereupon the aforementioned second end of the deformable sleeve can be screwed to the housing base by the fastening means.

[0010] The following aspects of the invention disclosed below can be combined with one another in any desired manner, provided that they do not contradict one another. These aspects are the aspects defined in the claims and the further developments thereof that are specified in the following description, including the description of the Figures, and that are also referred to as embodiments or embodiment examples.

[0011] According to a first aspect of the invention, at least two support points spaced apart from one another along the axis of rotation are provided for the rotational support of the drive shaft, wherein all the support points are located on the side of the drive motor facing the eccentric section and / or between a front balancing weight and a rear balancing weight of the drive shaft.

[0012] In other words, the drive motor is located behind the support points, i.e. there is no longer a support point behind the drive motor. This simplifies the assembly and replacement of the drive motor or of parts of the drive motor, in particular the motor rotor or a unit comprising the motor rotor. This concept represents a departure from a conventional arrangement in which a drive motor configured as an asynchronous motor is arranged between two support points spaced apart along the axis of rotation.

[0013] According to some further developments, it can be provided that the eccentric section is connected to the front end of the drive shaft and the drive motor is seated on the rear end of the drive shaft.

[0014] In some embodiment examples, provision can be made that the drive motor is arranged at least partly, preferably completely, within the pump housing. In particular, the drive motor is in this respect surrounded at least over more than half of its axial length, preferably over its entire axial length, by the pump housing in the peripheral direction.

[0015] In this respect, it can be provided that the pump housing is closed at its rear end by means of a separate motor cover. If the drive motor is not arranged completely within the pump housing, the motor cover can have a receiving space having an axial depth that is dimensioned such that this receiving space can accommodate a rear end of the drive motor projecting axially to the rear out of the pump housing.

[0016] According to preferred embodiments of this aspect of the invention, the electric drive motor of the scroll vacuum pump can be an asynchronous motor.

[0017] Alternatively, the electric drive motor can be a synchronous motor.

[0018] In particular, the electric drive motor can be configured as an IPM motor (IPM=Internal Permanent Magnet).

[0019] Provision can also be made that the drive motor is a synchronous reluctance motor.

[0020] According to a second aspect of the invention, a balancing weight is placed at the end face onto the rear end of the drive shaft.

[0021] One advantage of this arrangement of the balancing weight is that installation space for the balancing weight does not have to be provided elsewhere. A further advantage is that the balancing weight can take over one or more additional functions in addition to the balancing of the rotating system. In particular, the balancing weight placed at the end face can serve to clamp the rotor of the drive motor.

[0022] The balancing weight rotating during the operation generates air turbulence in the motor space and can hereby produce a cooling effect and at least contribute to the cooling of the drive motor. The arrangement of cooling fins at the motor rotor can be omitted in this way so that the installation space hereby freed up in the motor space can be used for the balancing weight.

[0023] Here, “placed” does not necessarily mean that the balancing weight contacts the drive shaft. The balancing weight is located behind the drive shaft and is connected to the drive shaft such that it rotates together with the drive shaft during the operation.

[0024] The balancing weight can be screwed to the drive shaft, for example.

[0025] To screw the balancing weight to the drive shaft, a central screw, whose shank coincides with the axis of rotation, can be provided.

[0026] According to some embodiment examples, it can be provided that the positioning of the balancing weight in the peripheral direction relative to the drive shaft is predefined by a positioning aid.

[0027] The positioning aid can comprise a positioning element arranged at a radial distance from the axis of rotation and a positioning receiver for a part of the positioning element, wherein the positioning element is arranged at the drive shaft and the positioning receiver is formed at the balancing weight, or vice versa. The positioning element can, for example, be pin-shaped and can extend parallel to the axis of rotation.

[0028] The positioning element can be insertable in an axial direction into a recess during the assembly. The recess can be formed in the drive shaft. Alternatively, the recess can be formed jointly by the drive shaft, on the one hand, and a motor rotor of the drive motor or a radially inner sleeve element, which is rotationally fixedly connected to the motor rotor of the drive motor, on the other hand.

[0029] According to some further developments, it can be provided that the drive motor comprises a radially inner motor rotor and a radially outer motor stator, wherein the motor rotor is clamped between an abutment and the balancing weight placed onto the rear end of the drive shaft.

[0030] According to some embodiment examples, it can be provided that the drive motor comprises a radially inner motor rotor that is pushed onto the drive shaft, in particular with a clearance fit, directly or by means of a radially inner sleeve element rotationally fixedly connected to the motor rotor, wherein a form-fitted connection active in the peripheral direction is provided between the motor rotor and the sleeve element, on the one hand, and the drive shaft, on the other hand.

[0031] The form-fitted connection can be formed by a positioning element of a positioning aid, by which positioning aid the positioning of the balancing weight is predefined in the peripheral direction relative to the drive shaft. The positioning element and / or the positioning aid can be the positioning element described above or the positioning aid described above.

[0032] According to some embodiment examples, it can be provided that the motor rotor of the drive motor is provided with a radially inner sleeve element which is rotationally fixedly connected to the motor rotor and with which the motor rotor is pushed onto the drive shaft, in particular with a clearance fit. The sleeve element can be the sleeve element described above.

[0033] According to a third aspect of the invention, the drive motor comprises a radially inner motor rotor and a radially outer motor stator, wherein the motor rotor is provided with a radially inner sleeve element which is rotationally fixedly connected to the motor rotor and with which the motor rotor is pushed onto the drive shaft, in particular with a clearance fit.

[0034] The sleeve element is in particular the sleeve element described above.

[0035] With such a sleeve element, the inner diameter of the motor rotor can be adapted to the outer diameter of the respective section of the drive shaft. This can be advantageous, for example, in a system comprising a plurality of scroll vacuum pumps of different designs that differ from one another with respect to the inner diameter of the motor rotor. In particular, it is hereby made possible to use one drive shaft for different motor rotors.

[0036] The sleeve element can be formed in one part or in multiple parts.

[0037] The motor rotor and the sleeve element can be pressed together.

[0038] Furthermore, it can be provided that the sleeve element is provided with a peripheral shoulder which the motor rotor contacts. This shoulder can form an abutment for the motor rotor that can be clamped between this abutment and a clamping element. The clamping element can, for example, be placed at the end face onto the rear end of the drive shaft. In particular, the clamping element can be a balancing weight, in particular the balancing weight described above.

[0039] Furthermore, it can be provided that the drive shaft is provided with a peripheral shoulder which the sleeve element contacts. The shoulder of the drive shaft can form an abutment for the sleeve element when the sleeve element is clamped during the assembly. For example, the sleeve element can be clamped between this abutment and a clamping element placed at the end face onto the rear end of the drive shaft. The clamping element can, for example, be a balancing weight, in particular the balancing weight described above.

[0040] According to a fourth aspect of the invention, which relates to a scroll vacuum pump system comprising a plurality of scroll vacuum pumps of different designs, the drive shafts of the different scroll vacuum pumps are of identical design.

[0041] An advantageous reduction in the number of different components hereby results since the same drive shaft can be used for the different scroll vacuum pumps.

[0042] For example, the scroll vacuum pumps can differ from one another with respect to the inner diameter of a radially inner motor rotor of the drive motor, wherein, in order to adapt the drive shafts to the different inner diameters, sleeve elements of different wall thicknesses are provided that are arranged between the drive shaft and the motor rotor in each case.

[0043] In this respect, it can be provided that the motor rotors are each rotationally fixedly connected to the sleeve element and are pushed onto the drive shaft with the sleeve element, in particular with a clearance fit.

[0044] In this respect, it can be provided that the motor rotor and the sleeve element are pressed together in each case.

[0045] According to a fifth aspect of the invention, the drive shaft is provided with a front balancing weight and with a rear balancing weight, wherein the front balancing weight and the rear balancing weight differ from one another with respect to the material from which they are made.

[0046] Due to the concept of using different materials for the balancing weights, an additional parameter is provided that can be varied in order to adapt the balancing weights to the respective conditions.

[0047] In a system of scroll vacuum pumps of different designs, the installation space available for a balancing weight can be of different sizes, for example, due to pump systems of different sizes, which, however, does not necessarily have to mean that a smaller balancing mass is also in the case of a smaller installation space since the required balancing mass depends on the properties of the entire rotating system. In other words, with such a scroll vacuum pump system, it can be necessary to accommodate a comparatively large balancing mass in a comparatively small installation space in order to meet the respective requirements of the balancing, but to avoid or at least minimize design adjustments in the process.

[0048] By selecting a material with a higher density for one of the balancing weights, its mass can be increased without requiring a larger installation space for this balancing weight.

[0049] Advantageous further developments can therefore provide that the material of the one balancing weight has a greater density than the material of the other balancing weight. In particular, it can be provided that it is the front balancing weight whose material has a greater density. With the same dimensions of the remaining rotating system, pump systems of different sizes can hereby be compensated by balancing weights of different densities.

[0050] In particular, it can be provided that the front balancing weight is made of brass and the rear balancing weight is made of steel.

[0051] According to a sixth aspect of the invention, which relates to a scroll vacuum pump system comprising a plurality of scroll vacuum pumps of different designs, the scroll vacuum pumps differ with respect to the pump system, wherein the drive shaft is provided with a front balancing weight and with a rear balancing weight, and wherein the scroll vacuum pumps differ from one another with respect to the front balancing weight and / or the rear balancing weight.

[0052] According to a seventh aspect of the invention, the drive shaft is provided with at least one balancing weight, wherein the balancing weight comprises a plurality of balancing sections that follow one another along a longitudinal axis, which extends parallel to the axis of rotation of the drive shaft in the installed state, that each have a part ring shape and that surround the drive shaft with their opening facing towards the drive shaft, and wherein the balancing sections differ from one another with respect to the width of their openings.

[0053] An available installation space can be optimally utilized by a balancing weight having such different balancing sections.

[0054] The balancing weight having the different balancing sections can be the front balancing weight of the drive shaft that additionally has a rear balancing weight.

[0055] In some embodiment examples, it can be provided that, in the installed state, the opening widths of the balancing sections increase in the direction of the pump system.

[0056] Furthermore, it can be provided that, in the installed state, a balancing section is arranged at the height of the eccentric section of the drive shaft with respect to the axis of rotation of the drive shaft.

[0057] The opening of each balancing section can be defined in a plane perpendicular to the longitudinal axis by a part circle having a radius that is constant along the longitudinal axis, wherein the openings of the balancing sections differ from one another with respect to the size of the radii.

[0058] The part circles are preferably not arranged concentrically.

[0059] The part circles can each comprise an angle in the range from 120° to 180°, in particular in the range from 150° and 170°.

[0060] The balancing weight can be designed in one piece. It is hereby possible to manufacture the balancing weight from a single initial workpiece by a chip-forming machining.

[0061] Furthermore, it can be provided that the centers of all the part circles of at least two balancing sections, in particular of all the balancing sections, lie in a plane in which the bisectors of the angles encompassed by the part circles also lie.

[0062] According to an eighth aspect of the invention, the drive shaft is provided with at least one balancing weight that comprises at least one balancing section that widens radially outwardly conically in a plane perpendicular to a longitudinal axis that extends parallel to the axis of rotation of the drive shaft in the installed state.

[0063] With regard to a series production of scroll vacuum pumps and the resulting requirement for a correspondingly large number of balancing weights, the conical design of the balancing weight enables a material and cost optimization. The conical shape enables an imaginary rosette-like arrangement of a plurality of balancing sections around a center axis, which is equivalent to the circular surface, and thus the material of a circular disk-shaped initial workpiece, being able to be optimally utilized, i.e. a high packing density of balancing weights in the workpiece being able to be realized, so to speak. The proportion of material that is not used for the manufacture of balancing weights can thus be minimized.

[0064] The longitudinal axis can coincide with the axis of rotation. In this respect, it can be provided that the balancing section widens in a V shape and thus defines an opening angle in the range from 10° to 30°, in particular in the range from 15° to 25°.

[0065] In a projection along the axis of rotation, the outline of the balancing section can be bounded by two straight lines diverging radially outwardly in a V shape, a radially inner circular section and a radially outer circular section. The radially inner circular section can have a smaller radius than the radially outer circular section. An imaginary circle, on which the radially inner circle section lies and whose center preferably lies on the longitudinal axis, can lie completely within the outline of the balancing section. Alternatively or additionally, an imaginary circle on which the radially outer section of the circle lies can completely contain the outline of the balancing section.

[0066] Such designs of the balancing section can further increase the material yield.

[0067] According to some embodiment examples, it can be provided that the balancing weight comprises a plurality of balancing sections that follow one another along a longitudinal axis, which extends parallel to the axis of rotation of the drive shaft in the installed state, wherein, in a projection along the longitudinal axis, the outline of the entire balancing weight is formed by the outline of the radially outwardly conically widening balancing section. It can hereby be achieved that the further balancing section or sections do not impair the material yield.

[0068] At least one further balancing section can be provided that is shortened in a radial direction with respect to the radially outwardly conically widening balancing section and, apart from this, is designed as congruent with said radially outwardly conically widening balancing section and is oriented overlapping the latter. The manufacture of the balancing weight can hereby be further simplified.

[0069] The balancing weight can have a circular cylinder section that forms the end-face end of the balancing weight along the longitudinal axis and whose center axis coincides with the longitudinal axis. In this respect, it can in particular be provided that the thickness of the circular cylinder section measured along the longitudinal axis is less than the thickness of each balancing section.

[0070] The circular cylinder section can, for example, serve for the centering of the balancing weight during the assembly. In particular, the balancing weight can be inserted with the circular cylinder section into a sleeve element, and indeed in particular in those embodiment examples in which the balancing weight is placed at the end face onto the rear end of the drive shaft, wherein a motor rotor is rotationally fixedly connected to the sleeve element and is pushed onto the drive shaft with the sleeve element.

[0071] The balancing weight can be placed with the circular cylinder section at the end face onto the rear end of the drive shaft.

[0072] The balancing weight can have its greatest thickness measured along the longitudinal axis in extension of the drive shaft.

[0073] In particular, it can be provided that the balancing weight is designed in one piece. Due to the single-piece design, the manufacture of the balancing weight can be simplified further.

[0074] According to a ninth aspect of the invention, which relates to a system comprising a plurality of scroll vacuum pumps of different designs, each vacuum pump comprises a pump housing and an electronics housing, wherein the pump system, the drive shaft and the drive motor are accommodated in the pump housing and the electronics housing is a component that is separate from the pump housing and that is connected, in particular releasably, to the pump housing, wherein the electronics housing comprises a housing part and electronic equipment, wherein the scroll vacuum pumps differ from one another with respect to the electronic equipment, wherein the housing parts of the different scroll vacuum pumps are of identical design.

[0075] Different electronic equipment can, for example, result from the scroll vacuum pumps being equipped with different drive motors. Different drive motors can require different electronic, electrical and / or electromechanical components and / or a different number of such components.

[0076] The use of one housing part for different electronic equipment is equivalent to a modular system for the different scroll vacuum pumps, which simplifies the manufacture and thus reduces the costs.

[0077] The housing parts can each be formed as a cast part.

[0078] The fact that the housing parts of the different scroll vacuum pumps are of identical design does not preclude, according to advantageous further developments, the housing parts of the different scroll vacuum pumps from differing from one another with respect to a post-processing for adaptation to the respective electronic equipment. The post-processing can, for example, comprise adapting one or more apertures to the geometry of plugs or lines of the electronic equipment that are to be received at the housing part or that are to be guided through a wall of the housing part. A post-processing can, for example, also comprise walls that are present within the housing part being party or completely removed by a milling in order thus to adapt the available installation space to the respective space requirements of the electronic equipment.

[0079] According to a tenth aspect of the invention, the drive motor comprises a radially inner motor rotor and a radially outer motor stator, wherein the motor rotor has a front end face and a rear end face, and wherein only one of the two end faces is provided with cooling projections projecting in an axial direction.

[0080] This represents a departure from a conventional design that is characterized in that such cooling projections are present on both end faces of the motor rotor. Since, according to this aspect of the invention, the cooling projections are only present on one end face, axial installation space is advantageously saved. It was surprisingly found that only cooling projections provided at one side can provide a sufficient cooling effect.

[0081] In some embodiment examples, it can be provided that at least some of the cooling projections are configured and arranged such that they are each effective as a balancing weight. In this respect, these balancing weights can together form an effective balancing mass with respect to the axis of rotation. It was surprisingly found that, with an only one-sided arrangement of these projections, both a sufficient cooling effect and a sufficient balancing effect can be achieved.

[0082] It can be provided that it is the rear end face of the motor rotor that is provided with the cooling projections. The front end face of the motor rotor, which is not provided with such projections, can thus be arranged further inwardly than in the case of a motor rotor that is provided with such projections at its front end face.

[0083] The cooling projections can be rib-shaped or plate-shaped.

[0084] It can be provided that the cooling projections have at least two different sides that differ from one another with respect to their width, wherein the cooling projections are arranged such that in each case the wider side at least substantially faces in the peripheral direction and the narrower side at least substantially faces in the radial direction. As a result, the cooling projections can generate comparatively strong air movements in the manner of blades, i.e. can ensure a comparatively large “whisking or stirring effect”, which favors the heat dissipation and thus the cooling effect. The cooling projections can be designed as curved such that they at least substantially face in the peripheral direction with a concavely shaped side, and indeed in the direction of rotation of the motor rotor. The blade effect of the cooling projections can hereby be further improved.

[0085] According to an eleventh aspect of the invention, the stationary spiral component comprises a spiral arrangement, which has spiral walls and a spiral base, and a support for the spiral arrangement, wherein, in the support, an outlet channel is formed that is formed by an inlet opening formed in the spiral base and that leads to an outlet of the support, and wherein, in the support, in addition to the outlet channel, at least two bypass channels are formed which each lead from a bypass opening formed in the spiral base to an outlet of the support and in each of which at least one pressure relief valve is arranged.

[0086] The provision of a bypass channel comprising one or more pressure relief valves in the pump system of a scroll vacuum pump is generally known. An excess pressure that is produced in certain pump applications and that would lead to a particularly high power consumption of the pump can be avoided in this way.

[0087] It was surprisingly found that a plurality of bypass channels, each having one or more pressure relief valves, enable a further improvement in that a comparatively high pumping speed is achieved with a relatively low power consumption.

[0088] In some further developments, it can be provided that the bypass channels each lead to the outlet channel. One or more additional outlets for the bypass channels are then not required.

[0089] Preferably, exactly two bypass channels are provided. It was found that just two bypass channels are sufficient to achieve a particularly favorable ratio of the power consumption and the pumping speed.

[0090] According to further embodiment examples, it can be provided that exactly one pressure relief valve is arranged in each bypass channel. It was found that one pressure relief valve per bypass channel is sufficient to achieve a particularly favorable ratio of power consumption to pumping speed.

[0091] The stationary spiral component is preferably formed in one piece, wherein the side of the support facing the movable spiral component forms the spiral base of the spiral arrangement.

[0092] In some embodiment examples, it can be provided that the two bypass openings are arranged offset from one another in the peripheral direction, in particular by an angle of less than 180°, preferably by an angle between 90° and 18020 .

[0093] Furthermore, it can be provided that the two bypass openings are arranged at different radial positions or at at least substantially the same radial position with respect to a center axis of the stationary spiral component, which center axis extends parallel to the axis of rotation of the drive shaft.

[0094] Furthermore, it can be provided that the inlet opening of the outlet channel is arranged radially further inwardly than both bypass openings with respect to a center axis of the stationary spiral component, which center axis extends parallel to the axis of rotation of the drive shaft. The inlet opening of the outlet channel can in particular be arranged at least substantially on the center axis.

[0095] According to a twelfth aspect of the invention, the stationary spiral component comprises a spiral arrangement, which has spiral walls and a spiral base, and a support for the spiral arrangement, wherein, in the support, an outlet channel is formed that leads from an inlet opening formed in the spiral base to an outlet of the support, and wherein, in the support, in addition to the outlet channel, at least two bypass channels are formed that each lead from a bypass opening formed in the spiral base to the outlet channel.

[0096] Since the bypass channels lead to the outlet channel, it is not necessary to provide one or more additional outlets for the bypass channels in the support.

[0097] It can be provided that the outlet of the support comprises a radial outlet opening and that the outlet channel comprises a radially extending channel section leading to the radial outlet opening.

[0098] In this respect, it can be provided that both bypass channels lead to the radial channel section in each case.

[0099] Alternatively, it can be provided that the one bypass channel leads to the radial channel section and the other bypass channel leads to a further channel section of the outlet channel that leads from the inlet opening to the radial channel section.

[0100] In this respect, it can be provided that the further channel section of the outlet channel extends parallel to a center axis of the stationary spiral component, which center axis extends parallel to the axis of rotation of the drive shaft, and in particular lies on the center axis.

[0101] According to some embodiment examples, it can be provided that at least one pressure relief valve is arranged in each of the bypass channels.

[0102] According to a thirteenth aspect of the invention, the stationary spiral component comprises a spiral arrangement, which has spiral walls and a spiral base, and a support for the spiral arrangement, wherein, in the support, an outlet channel is formed that is formed by an inlet opening formed in the spiral base and that leads to an outlet of the support, and wherein the outlet of the support comprises an axial outlet opening.

[0103] The axial outlet opening is in particular advantageous if the outlet is to be used for a further function that requires additional installation space. For example, it may be desired to integrate an additional device into the scroll vacuum pump, for example a leak detector, that must be connected to the outlet of the support. With a conventional radial outlet opening, this additional function would require an additional radial installation space that is often not available. An axial installation space, on the other hand, is to be realized in many cases without disadvantages. Consequently, an additional device, such as a leak detector, can be connected to the axial outlet opening of the support without additional radial installation space being required. The scroll vacuum pump can therefore be made slimmer.

[0104] Accordingly, in some embodiments, it can be provided that a vacuum device can be connected to or is connected to the axial outlet opening, wherein the vacuum device can in particular be a leak detector.

[0105] The outlet channel can comprise a radially extending channel section and at least one further channel section that leads from the radially extending channel section to the axial outlet opening.

[0106] In this respect, the further channel section can extend parallel to a center axis of the stationary spiral component that extends parallel to the axis of rotation.

[0107] In some embodiment examples, it can be provided that the outlet of the support comprises a radial outlet opening in addition to the axial outlet opening, wherein the two outlet openings are selectively closable so that the support can be operated with only a single outlet opening. The scroll vacuum pump can hereby be flexibly operated. The respective outlet opening that is not required can be closed by means of a plug, for example. To insert and remove such a plug, an aperture can be formed in surrounding components, for example a hood, through which aperture the respective outlet opening or a plug that is currently closing it is accessible.

[0108] The outlet channel can comprise a radially extending channel section that leads to the radial outlet opening, wherein a further channel section leads from a branching point of the radial channel section, which branching point is disposed between the inlet opening and the radial outlet opening, to the axial outlet opening. In this respect, it can be provided that a channel section, which starts from a bypass opening formed in the spiral base, leads to an opening point that is particular disposed between the inlet opening and the branching point leading to the axial outlet opening.

[0109] The axial outlet opening can be formed at a radially outer region of the support. In particular, Ra>0.5 * r, in particular Ra>0.7 * r, in particular Ra>0.8 * r, can apply to the radial position Ra of the axial outlet opening if r is the radius of the support.

[0110] According to a fourteenth aspect of the invention, the movable spiral component comprises a spiral arrangement, which has spiral walls, spiral grooves bounded by said spiral walls and a spiral base forming the base of said spiral grooves, and a support for the spiral arrangement, said support cooperating with the eccentric section of the drive shaft, and the stationary spiral component comprises a spiral arrangement, which has spiral walls, spiral grooves bounded by said spiral walls and a spiral base forming the base of said spiral grooves, and a support for the spiral arrangement, wherein the spiral grooves have a groove depth, which is measured from the tip of the spiral walls up to the spiral base along a center axis of the movable spiral component, which center axis extends parallel to the axis of rotation of the drive shaft, and a groove width measured perpendicular to the center axis, and wherein, in the movable spiral component and / or in the stationary spiral component, the ratio of groove depth to groove width is in a range from 3.7 to 4.2, in particular from 3.8 to 4.1, in particular preferably from 3.85 to 4.0, and / or wherein the ratio of groove depth to groove width is greater than 3.8, in particular greater than 3.85, or less than 4.0.

[0111] With such dimensions of the spiral grooves, the pump system can achieve a comparatively high pumping speed.

[0112] The ratio of groove depth to groove width is preferably constant over the entire spiral arrangement.

[0113] The groove depth can amount to 50 mm, for example. Alternatively, the groove depth can amount to 52 mm. Even higher ratios of groove depth to groove width—with the same groove width—hereby result that are in the range from 4.0 and 4.2, for example.

[0114] According to a fifteenth aspect of the invention, the movable spiral component comprises a spiral arrangement, which has spiral walls, spiral grooves bounded by said spiral walls and a spiral base forming the base of said spiral grooves, and a support for the spiral arrangement, said support cooperating with the eccentric section of the drive shaft, and the stationary spiral component comprises a spiral arrangement, which has spiral walls and a spiral base, and a support for the spiral arrangement, wherein, in the movable spiral component and / or in the stationary spiral component, one or more radially outwardly disposed spiral walls have a thickness that is greater than the thickness of radially further inwardly disposed spiral walls.

[0115] Due to the greater thickness, the radially outwardly disposed spiral wall or the radially outwardly disposed spiral walls can be given greater stability. This is in particular of advantage if the respective spiral wall is interrupted in the peripheral direction.

[0116] According to some embodiment examples, it can be provided that the support is provided with a gas inlet in a radially outwardly disposed region, the spiral wall or the spiral walls being interrupted in the peripheral direction in the region of said gas inlet, wherein at least one, preferably each, of the spiral walls interrupted in the peripheral direction is provided with the greater thickness.

[0117] In this respect, the gas inlet can comprise a recess, which starts from the outer margin of the support and preferably extends radially inwardly in a V shape, or can be formed by such a recess.

[0118] According to some embodiment examples, it can be provided that the or each spiral wall of greater thickness lies on a circle.

[0119] Furthermore, it can be provided that a plurality of, in particular two, radially outermost spiral walls of greater thickness lie on concentric circles, are interrupted in the peripheral direction in the region of a gas inlet formed in the support and bound a parallel pumping structure composed of circular or circular section-shaped channels that pump in parallel and that merge into a helical pump channel that is bounded by at least one spiral wall of smaller thickness that extends in a helical shape.

[0120] According to a sixteenth aspect of the invention, the movable spiral component comprises a spiral arrangement, which has spiral walls, spiral grooves bounded by said spiral walls and a spiral base forming the base of said spiral grooves, and a support for the spiral arrangement, said support cooperating with the eccentric section of the drive shaft, wherein the stationary spiral component comprises a spiral arrangement, which has spiral walls and a spiral base, and a support for the spiral arrangement, wherein the spiral walls of the movable spiral component and / or the spiral walls of the stationary spiral component are provided with a sealing element at their end facing away from the spiral base, and wherein, at least in one spiral wall, the sealing element is guided up to the end of the spiral wall that reaches up to a gas inlet of the pump system.

[0121] For manufacturing reasons, it has so far been avoided to design such sealing elements so long that they can be guided up to this end of the spiral wall. For example, an end section of the spiral wall covering an angular range of approximately 180° was previously left without a sealing element. It was surprisingly found that there is a relevant improvement in the pumping speed of the scroll vacuum pump if the sealing element is guided up to the end of the spiral wall.

[0122] In some embodiment examples, it can be provided that the sealing element is of elongate shape and extends continuously from a radially outwardly disposed end up to a radially inwardly disposed end.

[0123] It can be provided that the sealing element has a length of more than 150 cm, in particular of approximately 160 cm.

[0124] The sealing element can consist of a thermoplastic material, in particular of PTFE (polytetrafluoroethylene), or can comprise such a material.

[0125] The sealing element is preferably received in a groove of the respective spiral wall.

[0126] The gas inlet of the pump system can comprise a recess formed at the support of the movable spiral component. In particular, it can in this respect be provided that the recess starts from the outer margin of the support and preferably extends radially inwardly in a V shape.

[0127] The invention will be described in the following by way of example with reference to the drawing. There are shown:

[0128] FIGS. 1a and 1b an embodiment example of a scroll vacuum pump according to the invention of a first design with a three-phase asynchronous motor;

[0129] FIGS. 2a and 2b an embodiment example of a scroll vacuum pump according to the invention of a second design with a three-phase asynchronous motor;

[0130] FIGS. 3a and 3b an embodiment example of a scroll vacuum pump according to the invention of a third design with an IPM motor;

[0131] FIGS. 3c, 3d and 3e different views to explain embodiment examples of a balancing system according to the invention in conjunction with the scroll vacuum pump according to FIGS. 3a and 3b;

[0132] FIG. 4 an aspect of the invention relating to the balancing of the motor rotor using the example of the scroll vacuum pump according to FIGS. 1a and 1b;

[0133] FIGS. 5a and 5b in each case, the electronics housing of a scroll vacuum pump according to the invention, namely FIG. 5a the electronics housing of a scroll vacuum pump according to FIGS. 3a and 3b, and FIG. 5b the electronics housing of a scroll vacuum pump according to FIGS. 1a and 1b or FIGS. 2a and 2b;

[0134] FIGS. 6a, 6b and 6c different views of an embodiment example of a stationary spiral component of a scroll vacuum pump according to the invention;

[0135] FIGS. 7a and 7b an embodiment example of a movable spiral component for the stationary spiral component of FIGS. 6a, 6b and 6c;

[0136] FIGS. 8a, 8b, 8c and 8d different views to explain the pump system with the stationary spiral component according to FIGS. 6a, 6b and 6c and the movable spiral component according to FIGS. 7a and 7b;

[0137] FIG. 9 a schematic representation to explain the relative arrangement between the stationary spiral component and the movable spiral component in different states of an embodiment example of a scroll vacuum pump according to the invention; and

[0138] FIG. 10 different external views of a scroll vacuum pump according to the invention according to FIGS. 2a and 2b or FIGS. 3a and 3b.

[0139] The scroll vacuum pumps according to the invention shown in FIGS. 1a and 1b, FIGS. 2a and 2b and FIGS. 3a and 3b belong to a scroll vacuum pump system comprising a plurality of scroll vacuum pumps of different designs. The scroll vacuum pumps of this system differ from one another in multiple respects, but have the same basic design that is described below.

[0140] Each scroll vacuum pump comprises a pump system having a stationary spiral component 11 and a movable spiral component 13 that cooperate in a pump-active manner during the operation. Each scroll vacuum pump further comprises a drive shaft 16 that rotates about an axis of rotation 15 during operation and that has an eccentric section 19 for driving the movable spiral component 13. Furthermore, each scroll vacuum pump is provided with an electric drive motor 21, 23 that serves to set the drive shaft 17 into rotation about the axis of rotation 15. The electric drive motor comprises a radially inner motor rotor 21 and a radially outer motor stator 23.

[0141] In each scroll vacuum pump, the drive shaft 17 is rotatably supported at the pump housing 41 at two support points 25, 27 spaced apart in the axial direction. The front rolling element bearing 25 is configured as a fixed bearing, while the rear rolling element bearing 27 is configured as a floating bearing.

[0142] A particular feature provided in all the scroll vacuum pumps of the system is that an arrangement also designated as a cantilever concept is provided, according to which the two support points 25, 27 are located at the side of the drive motor 21, 23 facing the eccentric section 19 of the drive shaft 17. All the support points 25, 27 are thus located within the pump housing 41 in front of the drive motor 21, 23.

[0143] The eccentric section 19 is connected in one piece to the front end of the drive shaft 17 and the drive motor 21, 23 is seated on the rear end of the drive shaft 17.

[0144] Due to this basic design, the drive motor 21, 23 can be pushed onto the rear end of the drive shaft 17, which simplifies the assembly and the replacement of the drive motor or of parts of the drive motor.

[0145] The balancing concept for balancing the rotating system, which inter alia comprises the drive shaft 17 and the movable spiral component 13, comprises a front balancing weight 29 fastened to the drive shaft 17 by means of a screw 38 and a rear balancing weight 31 in each scroll vacuum pump disclosed here. In this respect, the front balancing weight 29 is in each case arranged in the region of the front end of the drive shaft 17 and the eccentric section 19. In the pump according to FIGS. 1a and 1b, the rear balancing weight 31 is located in front of the rear support point 27 and thus in front of the drive motor. In the scroll vacuum pumps according to FIGS. 2a and 2b and FIGS. 3a and 3b, according to one aspect of the scroll vacuum pumps of this design, it is provided that the rear balancing weight 31 is formed by a pressure element that is placed at the end face onto the rear end of the drive shaft 17. In the scroll vacuum pump according to FIGS. 1a and 1b, a pressure element 87 (FIG. 1b) placed at the end face onto the rear end of the drive shaft 17 is provided that is, however, rotationally symmetrical and thus does not serve as a balancing weight.

[0146] The pressure elements 87 and 31 are connected to the drive shaft 17 by a central screw 83 in each case. The motor rotor 21 is hereby in each case clamped between the rotationally symmetrical pressure element 87 or the pressure element 31, which is simultaneously configured as a balancing weight, on the one hand, and an abutment, on the other hand, wherein this abutment is formed by a shoulder 17a formed at the drive shaft 17.

[0147] A further particular feature of the scroll vacuum pump system according to the invention is that the drive shafts 17 of the different scroll vacuum pumps are of identical design. Despite different motor sizes within the system, only one drive shaft 17 is therefore required for the system. The drive motors of the scroll vacuum pumps of different designs inter alia differ with respect to the inner diameter of the radially inner motor rotor 21. This is shown, for example, by the comparison of FIG. 2b and FIG. 3b. To adapt the drive shafts 17 of identical design to the different inner diameters of the motor rotors 21, sleeve elements 33 with different wall thicknesses are provided that are arranged between the drive shaft 17 and the motor rotor 21 in each case. Such a sleeve element 33 is provided in the scroll vacuum pump according to FIG. 2b, whereas the scroll vacuum pump according to FIG. 3b does not have such a sleeve element. In the case of those scroll vacuum pumps that have such a sleeve element 33, said sleeve element is in each case rotationally fixedly connected to the respective motor rotor 21, wherein this connection between the motor rotor 21 and the sleeve element 33 is produced by pressing. Thus, the pressed-together unit of the motor rotor 21 and the sleeve element 33 can be pushed onto the rear end of the drive shaft 17 during the assembly. In this respect, a clearance fit is present between the sleeve element 33 and the drive shaft 17.

[0148] A corrugated spring is arranged between the sleeve element 33 and the floating bearing 27 in the region of the aforementioned shoulder 17a.

[0149] A pin-shaped positioning element 85 serves as a positioning aid for the respective pressure element 87 or 31 as a security against rotation when tightening the central screw 83 and as a form-fitted connection effective in the peripheral direction between the motor rotor 21 or the sleeve element 33, on the one hand, and the drive shaft 17, on the other hand. This positioning pin 85 extends parallel to the axis of rotation 15 of the drive shaft 17 and is arranged at a radial distance from the axis of rotation 15. During the assembly, the positioning pin 85 can be inserted in the axial direction into a recess that is formed jointly by the drive shaft 17, on the one hand, and the motor rotor 21 or the sleeve element 33 rotationally fixedly connected to the motor rotor 21, on the other hand. In the assembled state, the positioning pin 85 projects axially to the rear and is received with its rear end in a positioning receiver that is formed as a blind hole at the side of the pressure element 87 or 31 facing the rear end of the drive shaft 17.

[0150] The aforementioned clamping of the motor rotor 21 by means of the pressure element 87 or 31 takes place in that the pressure element 87 or 31 cooperates with the axially rear end of the sleeve element 33 (cf. FIGS. 1a and 1b and FIGS. 2a and 2b) or with the motor rotor 21 (cf. FIGS. 3a and 3b).

[0151] As an assembly aid when pressing the sleeve element 33 into the motor rotor 21, a radial incision101 is provided at the front end of the motor rotor 21 in the assembled state and serves as a marking for the fitter and thus indicates the installation orientation of the motor rotor 21 to the fitter.

[0152] In the scroll vacuum pumps according to FIGS. 2a and 2b as well as FIGS. 3a and 3b, the drive motor is arranged completely within the pump housing 41, i.e. the drive motor is surrounded over its entire axial length by the pump housing 41 in the peripheral direction. At its rear end, the pump housing 41 is closed by means of a separate motor cover 103. A particular feature of the scroll vacuum pumps according to FIGS. 2a and 2b as well as FIGS. 3a and 3b is that the motor covers 103 are of identical design despite the different motor sizes. In the scroll vacuum pump according to FIGS. 3a and 3b, the drive motor is smaller than in the scroll vacuum pump according to FIGS. 2a and 2b. Accordingly, the pump housing 41 has a greater radial wall thickness in this region. For both pump designs, the motor cover 103 of identical design can be screwed at the end face onto the rear end of the motor housing 41.

[0153] A further particular feature is that the motor cover 103 is provided with a laser engraving (not shown). This facilitates a variable design compared to a printing.

[0154] In the scroll vacuum pump according to FIGS. 1a and 1b, the drive motor is not arranged completely within the pump housing 41. The motor cover 103 has a receiving space that has an axial depth that is dimensioned such that the rear end of the drive motor projecting axially to the rear out of the pump housing 41 is received in this receiving space.

[0155] In this scroll vacuum pump, it is furthermore provided that the motor rotor 21 is provided with cooling projections 47 projecting in the axial direction at its rear end face. A particular feature here is that these cooling projections 47 are only arranged at this rear end face of the motor rotor 21 and the front end face of the motor rotor 21 has no such cooling projections. Axial installation space can hereby be advantageously saved. The cooling projections 47 are configured such that they each act as a balancing weight.

[0156] This aspect of the invention will be discussed again elsewhere.

[0157] The pump system having the stationary spiral component 11 and the movable spiral component 13 is located at the front end of the pump housing 41. The stationary spiral component 11, also called the spiral housing, is screwed at the end face onto the front end of the pump housing 41 and is surrounded by a hood 105 which is likewise attached to the pump housing 41 and in which a fan 95 is furthermore accommodated.

[0158] A particular feature of the scroll vacuum pump system is that a set of fans 95 with different performances but the same dimensions is provided. In this respect, not only fans 95 with a supply voltage of 24V are provided, but also those with a supply voltage of 48V or 230V, for example. This increases the variability of the system.

[0159] The movable spiral component 13 is connected to the eccentric section 19 via a flange bearing 91 configured as a rolling element bearing. A thrust washer 93 is located axially between the movable spiral component 13 and the eccentric section 19. A shim washer 94 is located between a peripheral shoulder of the drive shaft 17 at the transition into the eccentric section 19 and the flange bearing 91. The correct orientation in the peripheral direction between the stationary spiral component 11 and the pump housing 41 is ensured by a positioning pin 97.

[0160] In each scroll vacuum pump of the system, the pump housing 41 is supported on a base that is formed by an electronics housing 43. The electronics housing 43 comprises a housing part 43a that, at its lower side, is provided with feet 107 made of rubber that are received in recesses formed at the lower side and that are arranged in a recessed manner in this regard.

[0161] The electronics housings 43 of the different scroll vacuum pumps inter alia differ with respect to a housing cover 43b forming the lower cover of the housing part 43a. This will be looked at in more detail elsewhere.

[0162] In each of the electronics housings 43, electronic equipment 45 is accommodated that comprises electronic, electrical and electromechanical components that inter alia serve for the power supply and the control of the respective scroll vacuum pump. The scroll vacuum pumps of the scroll vacuum pump system according to the invention also differ from one another with respect to the electronic equipment 45.

[0163] A particular feature of the scroll vacuum pump system according to the invention is that the housing parts 43a of the different scroll vacuum pumps are of identical design. The housing parts 43a are each configured as a cast part. Despite the different electronic equipment 45 for the individual scroll vacuum pumps, only one housing part 43a is therefore required.

[0164] This modular principle reduces the effort and costs in the manufacture of the scroll vacuum pumps. The housing parts 43a differ slightly with respect to a post-processing for adaptation to the respective electronic equipment 45. Such a post-processing e.g. serves to adapt apertures to the geometry of plugs or lines of the electronic equipment 45 that must be received at the housing part or guided through a wall of the housing part. Furthermore, a post-processing can comprise inner walls of a respective housing part 43a being partly or completely removed by a milling in order to adapt the installation space available in the housing part 43a to the respective space requirements of the electronic equipment 45 in this way.

[0165] The pump housing 41 is screwed to the electronics housing 43.

[0166] In FIGS. 1a, 2a and 3a, in each case in a section B-B at the bottom center, the region of the scroll vacuum pump is shown at which a gas ballast valve is arranged. The gas ballast valves 79 are configured differently for the individual scroll vacuum pumps. In the scroll vacuum pump according to FIGS. 1a and 1b, the gas ballast valve 79 is provided with a closing cover 81. In the scroll vacuum pumps according to FIGS. 2a and 2b and 3a and 3b, the gas ballast valve 79 has a rotary knob 82 for making settings.

[0167] The respective arrangement of an inlet flange 77 and the arrangement of an outlet flange 78 can be seen in the representations at the top right in FIGS. 1a, 2a and 3a that each show a view of the scroll vacuum pump on the hood 105.

[0168] The gas to be pumped enters the pump system comprising the two spiral components 11, 13 via the inlet flange 77 and is discharged via the outlet flange 78.

[0169] The two scroll vacuum pumps according to FIGS. 1a and 1b and 2a and 2b are each equipped with a three-phase asynchronous motor 21, 23 to drive the drive shaft 17. The two scroll vacuum pumps inter alia differ with respect to their construction size. The pump system comprising the two spiral components 11, 13 and the asynchronous motor comprising the rotor 21 and the stator 23 have a smaller diameter in the scroll vacuum pump according to FIGS. 1a and 1b than in the scroll vacuum pump according to FIGS. 2a and 2b, wherein—as already mentioned—the two drive shafts 17 are of identical design and thus have the same size. The diameter of the drive shaft 17 in the region of the sleeve element 33 amounts to 24 mm in this embodiment example. As already mentioned, the respective correspondingly dimensioned sleeve element 33 pressed together with the motor rotor 21 serves to adapt the diameter of the drive shaft 17 in this region to the respective inner diameter of the motor rotor 21.

[0170] In the scroll vacuum pump according to FIGS. 3a and 3b, the pump system likewise has a diameter that is larger than in the pump system of the scroll vacuum pump according to FIGS. 1a and 1b. However, an asynchronous motor does not serve as the rotary drive for the drive shaft 17, but rather a single-phase IPM motor (IPM=Internal Permanent Magnet).

[0171] However, the scroll vacuum pump system according to the invention is not limited to these electric drive motors. For example, a synchronous reluctance motor can also be provided as a rotary drive for the drive shaft 17.

[0172] The choice of a respective drive motor takes place with respect to the desired performance, a respective desired energy consumption, customer requirements and application conditions.

[0173] Due to its versatile adaptability, the modular principle provided according to the invention is of particular advantage with respect to this variability desired in practice.

[0174] As already mentioned, the balancing system for balancing the rotating system, which in particular comprises the drive shaft 17 and the movable spiral component 13 of the pump system, in each case comprises a front balancing weight 29 and a rear balancing weight 31. In the scroll vacuum pump according to FIGS. 1a and 1b, the rear balancing weight 31 is located in front of the rear support point 27. The pressure element 87 for clamping the motor rotor 21 is designed as rotationally symmetrical here.

[0175] In the scroll vacuum pumps according to FIGS. 2a and 2b and FIGS. 3a and 3b, the pressure element placed at the end face onto the rear end of the drive shaft 17 simultaneously forms the rear balancing weight 31. Since, in these two scroll vacuum pumps, the pump system-as mentioned-has a larger diameter, due to the comparatively limited installation space available in the region of the eccentric section 19 of the drive shaft 17, the front balancing weight 29 is made of a material that has a greater density than the material of the rear balancing weight 31.

[0176] According to one aspect of the invention, it is accordingly provided that the front balancing weight 29 is made of brass and the rear balancing weight 31 is made of steel. In the scroll vacuum pump according to FIGS. 1a and 1b, on the other hand, the two balancing weights 29 and 31 are made of the same material, namely of steel.

[0177] As already mentioned in the introductory part, the eccentric drive formed by the drive shaft 17 having the eccentric section 19 is located within the pump housing 41 and is surrounded by a deformable sleeve in the form of a corrugated bellows 89. The corrugated bellows 89 serves, on the one hand, to seal the eccentric drive with respect to the suction region of the scroll vacuum pump and, on the other hand, as a security against rotation for the movable spiral component 13. For this purpose, the corrugated bellows 89 is fastened to the side of the movable spiral component 13 that faces the drive. The rear end of the corrugated bellows 89 is attached to a housing base within the pump housing 41 by means of screws.

[0178] The balancing concept of the scroll vacuum pumps according to the invention is explained in more detail below, and indeed using the scroll vacuum pump according to FIGS. 3a and 3b as an example. These explanations also apply to the scroll vacuum pump according to FIGS. 2a and 2b and, with respect to the front balancing weight 29, also to the scroll vacuum pump according to FIGS. 1a and 1b.

[0179] FIG. 3c shows in sections perpendicular to the axis of rotation 15 of the scroll vacuum pump according to FIGS. 3a and 3b, in the left-hand representation (section B-B in FIG. 3b), a view of the rear balancing weight 31 and, in the right-hand representation (section A-A in FIG. 3b), the arrangement of a balancing section of the front balancing weight 39 with respect to the corrugated bellows 89, the flange bearing 91 and the eccentric section 19 of the drive shaft 17.

[0180] The specific design of the balancing weights 31, 29 is described in more detail below in connection with FIGS. 3d and 3e.

[0181] The left-hand representation in FIG. 3c shows that the rear balancing weight, which is screwed to the drive shaft 17 by means of the central screw 83 and clamps the motor rotor 21 in the manner explained above, widens radially outwardly conically. While retaining the basic geometry of this rear balancing weight 31, during its manufacture, an optimal adaptation to different drive motors can take place comparatively easily.

[0182] As the right-hand representation shows, the balancing section, shown in section, of the front balancing weight 29 is configured as part ring-shaped such that the inner radius is adapted to the outer radius of the flange bearing 91. The available construction space is hereby optimally utilized.

[0183] In the left-hand representation at the bottom, the rear balancing weight 31 is shown in a side view. Among other things, the bores 39a for the central screw 83 and the blind hole 39b for receiving the positioning pin 85 are shown.

[0184] In the two left-hand representations, FIG. 3d shows the design of the front balancing weight 39 that is designed in one piece and -as mentioned above-can be made of different materials, in particular of materials of different densities such as brass, on the one hand, and steel, on the other hand.

[0185] The right-hand representation in FIG. 3d shows, in an enlarged section of FIG. 3b, the arrangement of the front balancing weight 29 in the region of the eccentric section 19 of the drive shaft 17 and the flange bearing 91.

[0186] The balancing weight 29 comprises three balancing sections 35 that, in the installed state, follow one another along the axis of rotation 15 of the drive shaft 17. Each balancing section 35 has a respective part ring shape, wherein, in the installed state, each balancing section faces towards the drive shaft 17 with its opening 37 and surrounds said drive shaft 17.

[0187] A particular feature is that the balancing sections 35 differ from one another with respect to the width of their openings 37. This can be seen both in the perspective view at the top left in FIG. 3d and in the top view at the bottom left in FIG. 3d.

[0188] A further particular feature of this front balancing weight 29 is that the opening 37 of each balancing section 35 is defined in a plane E perpendicular to the axis of rotation 15 (in the installed state) by a part circle with a radius that is constant along the center axis. In the installed state, a balancing section 35 with a radius R1 comprises a section 17b of the drive shaft 17 that is disposed directly behind the eccentric section 19. The adjoining balancing section 35 with the radius R2 comprises the flange bearing 91. The third balancing section 35 is located in an axial region at which heads of fastening screws for attaching the flange bearing 91 to the movable spiral component 13 are arranged. The radius of this balancing section 35 is therefore significantly larger than the radii R1, R2 of the other two balancing sections.

[0189] A particular feature is that the two radii R1, R2 are not the same size and, in addition, the two part circles are not concentrically arranged, as can in particular be seen in the bottom-left representation in FIG. 3d. In the embodiment example shown here, it applies that R1=22 mm and R2=28.3 mm, wherein the centers of the two part circles are offset from one another, but in this respect lie in the plane E in which the bisectors of the angles encompassed by the part circles lie. In the embodiment example shown here, these angles each amount to 180°. The center of the rear balancing section 35 in the installed state in this respect lies on the axis of rotation 15 since this balancing section comprises the central section 17b of the drive shaft 17. Accordingly, the other center of the part circle with the larger radius R2 lies outside the openings 37 of the balancing sections 35.

[0190] This design of the balancing weight 29 has the advantage that, without increasing the outer diameter, the center of mass of the central balancing section 35 comprising the flange bearing 91 can be positioned further radially outwardly than would be the case if the two centers were to coincide. In other words, a higher eccentric mass can be realized for this central balancing section 35 without increasing the external dimensions of the balancing weight 29.

[0191] It is hereby advantageously achieved that the available installation space can be optimally utilized and a sufficiently high balancing effect can be achieved.

[0192] FIG. 3e shows three views at the left of the rear balancing weight 31 that illustrate its design. The balancing weight 31 is designed in one piece.

[0193] The balancing weight 31 comprises two balancing sections 39 that widen radially outwardly conically. The balancing sections 39 each widen in a V shape, wherein they define an opening angle of approximately 20°.

[0194] Furthermore, the balancing weight 31 comprises a circular cylinder section 40 whose center axis coincides with the axis of rotation 15 of the drive shaft 17 in the installed state. The thickness of this circular cylinder section 40 measured along the axis of rotation 15 is substantially smaller than the thickness of each balancing section 39. As can, for example, be seen in FIG. 3b, in the installed state, the balancing weight 31 faces the rear end of the drive shaft 17 with its circular cylinder section 40. It can be seen from the example of the scroll vacuum pump according to FIGS. 2a and 2b that the balancing weight 31 is introduced with its circular cylinder section 40 into the sleeve element 33.

[0195] The balancing section 39 disposed between the circular cylinder section 40 and the outer balancing section 39 is shortened in a radial direction with respect to the outer balancing section 39 but, apart from this, is designed as congruent with said outer balancing section 39 and is oriented overlapping the latter. Both balancing sections 39 therefore widen in a V shape, i.e., in a projection along the axis of rotation 15, the outlines of the two balancing sections 39 are bounded by two straight lines diverging radially outwardly in a V shape. Furthermore, the two outlines of the balancing sections 39 are bounded by a radially inner circular section that has a smaller radius than a respective radially outer circular section that forms the radially outer boundary of the respective outline.

[0196] This design of the rear balancing weight 31 enables a simple and cost-effective manufacture and an easy adaptation to the respective drive motor. However, an adaptation is not absolutely necessary in every case. The rear balancing weight 31 can be designed such that it can interact both with the asynchronous motor of a scroll vacuum pump according to FIGS. 2a and 2b, i.e. in particular with the sleeve element 33, and with the IPM motor of a scroll vacuum pump according to FIGS. 3a and 3b.

[0197] In the representations of FIG. 3e, the bore 39a for the central screw 83 and the blind hole 39b for the positioning pin 85 can furthermore be recognized.

[0198] As regards the manufacture of the rear balancing weight 31, the conical shape enables a minimization of the material requirement. At the right in FIG. 3e, for the purpose of illustration, a manufacturing arrangement 109 is shown in which a plurality of balancing weights 31 are arranged on a circle like a rosette. It is hereby illustrated that a plurality of balancing weights 31 can be manufactured by a cutting from a planar material disk and by a subsequent individual machining.

[0199] FIG. 4 shows a view of the rear end of a scroll vacuum pump according to FIGS. 1a and 1b with the motor cover 103 removed. The rear end face of the motor rotor 21 can hereby be recognized that is surrounded by a part of the motor stator 23.

[0200] As already mentioned elsewhere, a particular feature here is that the motor rotor 21 is only provided with cooling projections 47 projecting in the axial direction at this rear end face. These cooling projections 47 are designed and arranged such that they act as balancing weights. The balancing concept of the scroll vacuum pump according to FIGS. 1a and 1b therefore comprises not only the front balancing weight 91 and the rear balancing weight 31 arranged in front of the second support point 27, but additionally the balancing weights 47 that are arranged at the rear end face of the motor rotor 21 and that simultaneously serve for cooling. These balancing weights or cooling projections 47 are plate-shaped and are arranged such that they each face in the peripheral direction with their wider side. The cooling projections 47 can hereby generate comparatively strong air movements during the operation in the manner of blades in order to promote a heat dissipation.

[0201] FIG. 5a shows the electronics housing 43 of the scroll vacuum pump according to FIGS. 3a and 3b whose drive motor is a single-phase IPM motor with an operating voltage of 24V / DC. The electronic equipment 45 in this respect comprises a Sub-D connector, a stand-by switch, an on / off switch and USB ports.

[0202] FIG. 5b shows the electronics housing 43 of the scroll vacuum pumps according to FIGS. 1a and 1b and FIGS. 2a and 2b that each have a three-phase asynchronous motor as the drive motor. These asynchronous motors can be operated with an operating voltage of up to 480V / AC.

[0203] The three-phase asynchronous motors require a higher protection class (in particular IP44) than the single-phase IPM motor for which a lower protection class (in particular IP40) is sufficient. These different protection classes result in different concepts for sealing the electronics housing 43.

[0204] In the electronics housing 43 for the scroll vacuum pump having a single-phase IPM motor in accordance with FIG. 5a, a housing cover 43b, for example made of aluminum, without its own seal is sufficient as a cover. Here, a recessed arrangement is provided for the housing cover 43b in the housing part 43a, wherein surfaces set back inwardly with respect to the lower side of a peripheral outer wall serve as a support for the housing cover 43b and are each provided with a sealing material. Due to its recessed arrangement, the housing cover 43b cannot be seen from the side.

[0205] This is different in the case of the electronics housing 43 for the scroll vacuum pumps comprising the three-phase asynchronous motors. The housing cover 43b, for example made of aluminum, is placed onto the lower side of the housing part 43a here. The lower side is provided with a sealing material-like the set-back support surfaces in the case of the housing part 43a in accordance with FIG. 5a-, wherein the inner side of the housing cover 43b is additionally covered over its entire surface with a sealing material composed of cellular rubber, for example.

[0206] A particularly effective sealing of the electronics housing 43 is hereby effected in order to meet the requirements of the higher protection class.

[0207] As already mentioned elsewhere, the electronics housings 43 also differ by the respective electronic equipment 45. For example, the electronics housing 43 in accordance with FIG. 5a is provided with a connection for a cooling device plug 44 to which a power supply unit for the power supply of the scroll vacuum pump can be connected. In contrast, the electronics housing 43 in accordance with FIG. 5b is fitted with a different power plug 44, for example a power plug of the Harting type.

[0208] In addition, the electronics housing 43 in accordance with FIG. 5b differs from the electronics housing 43 in accordance with FIG. 5a by the absence of the Sub-D connector, the standby switch, the on / off switch and the USB ports. The apertures provided for this purpose in the housing component 43a are concealed, for example with a foil. An IP protection class can hereby be made possible for the electronics housing 43 in accordance with FIG. 5b.

[0209] FIG. 6a shows, in an overview, different views of a stationary spiral component 11, also designated as a spiral housing, of a scroll vacuum pump according to the invention. The top three representations in FIG. 6a are shown enlarged in FIG. 6b, whereas the bottom three representations of FIG. 6a are shown enlarged in FIG. 6c.

[0210] Accordingly, FIG. 7a shows an overview with different representations of a movable spiral component 13, also designated as an orbiter, for the spiral housing 11 in accordance with FIGS. 6a, 6b and 6c.

[0211] FIGS. 8a, 8b, 8c and 8d show the cooperation of the spiral housing 11 and the orbiter 13 in the pump system of a scroll vacuum pump according to the invention and the arrangement of the gas channels in the pump system.

[0212] The stationary spiral component 11 comprises a spiral arrangement, which has spiral walls 49 and a spiral base 51, and a support 53 for the spiral arrangement. The two radially outer spiral walls 49 lie on concentric circles and are interrupted in the peripheral direction. This results in a parallel pumping structure of channels that pump in parallel, that are formed by the respective spiral grooves 50 and that merge into a helical pump channel that is formed by a spiral groove 50 extending in a helical shape and that is bounded by a spiral wall 49 extending in a helical shape.

[0213] The second part-circular spiral wall 49, viewed radially from the outside, has a greater thickness WD2 than the spiral wall 49 that extends in a spiral shape and that has a wall thickness WD1 in its radially further inwardly disposed course. In this embodiment example, it applies that WD2=3.71 mm and WD1=3.47 mm. The stability of the circular spiral wall 49, which is interrupted in the peripheral direction, is increased by this increased thickness WD2.

[0214] The spiral walls 49 are each provided with an elongated sealing element 75, which is also designated as a tip seal, at their end facing away from the spiral base 51. The sealing element 75 for the furthest radially outwardly disposed spiral wall 49 has a comparatively long length since it is continued to the further radially inwardly disposed spiral wall 49 extending in a spiral shape and extends up to the radially inner end of this spiral wall 49, said radially inner end being disposed in the region of the center axis of the spiral housing 11. A particular feature of this long sealing element 75 is that it is guided radially outwardly at the part-circular spiral wall 49 up to the end 76 of this spiral wall 49, which end extends up to a gas inlet 67 (cf. FIGS. 7a and 7b) of the pump system.

[0215] The gas pumped along the spiral grooves 50 from radially outside to radially inside can pass from the spiral grooves 50 via a central inlet opening 55 and via two bypass openings 61a, 63a into a channel system, described in more detail below, of the stationary spiral component 11. These openings 55, 61a, 63a are each formed in the spiral base 51. The two bypass openings 61a, 63a are arranged offset from one another in the peripheral direction and are located on the same radius with respect to a center axis of the spiral housing 11.

[0216] Aligned with these openings 55, 61a, 63a are openings 56a, 61c, 63c formed on the side of the support 53 facing away from the spiral arrangement. These openings 56a, 61c, 63c serve to receive valves that will be discussed in more detail elsewhere.

[0217] Furthermore, in this side of the support 53 facing away from the spiral arrangement, an axial outlet opening 65 is formed radially further outwardly that can selectively either be closed or can form an axial gas outlet of the scroll housing 11 and thus of the pump system of the scroll vacuum pump.

[0218] The openings mentioned communicate with a channel system of the spiral housing 11 that is shown in the representations at the left and the right in FIG. 6c.

[0219] The central inlet opening 55 leads to an outlet channel 59 that is designed as a straight bore and that opens at the radial outlet 57 of the spiral housing 11. The one bypass opening 63a leads directly to this outlet channel 59. The channel section leading from there to the radial outlet 57 is thus not only a section of the outlet channel 59, but furthermore forms a bypass channel 63 for gas coming from the bypass opening 63a.

[0220] A further bypass channel 61 (cf. the right-hand representation in FIG. 6c) leads from the further bypass opening 61c to the outlet channel59. This bypass channel 61 is part of a straight bore 64 that is formed to produce the bypass channel 61. This bore 64 and the outlet channel 69 extend at an angle to one another that corresponds to the angular offset of the two bypass openings 61c, 63c in the peripheral direction.

[0221] A further particular feature of the pump system according to the invention, which is evident in both the spiral housing 11 and the orbiter 13, is that the groove depth NT is comparatively large. In the embodiment example shown here, the groove depth amounts to 50 mm. This results in comparatively large values for the ratio of groove depth NT to groove width NB. With a groove width NB1=12.71 mm for the spiral groove 50 extending in a spiral shape and with a groove width NB2=12.92 mm for a spiral groove 50 that extends radially further outwardly and in a circle shape, ratios of 3.93 or 3.87 result. A groove depth of 52 mm can alternatively be provided. Even larger ratios of groove depth to groove width then result.

[0222] The movable spiral component 13 in accordance with FIGS. 7a and 7b likewise comprises a spiral arrangement, which has spiral walls 69 and a spiral base 71, and a plate-shaped support 73 for the spiral arrangement. The two radially outer spiral walls 69 run on concentric circles and are interrupted in the peripheral direction in the region of a gas inlet 67. A radially inwardly disposed spiral wall 69 extends in a spiral shape. The spiral walls 69 are in turn provided with a sealing element 75 (tip seal) at their end facing away from the spiral base 71.

[0223] To increase the stability of the two radially outwardly disposed spiral walls 69 that are interrupted in the peripheral direction, these spiral walls 69 are designed with a thickness WD2 that is greater than the thickness WD1 of the spiral-shaped spiral wall 69. In this embodiment example, it applies that WD2=3.71 mm and WD1=3.46 mm.

[0224] As can be seen from the representation at the right in FIG. 7b, the radially outer spiral groove 70 between the two spiral walls 69 of part circle shape has a groove width NB2, whereas the spiral groove 70 that is bounded by the spiral-shaped spiral wall 69 and that extends in a spiral shape has a groove width NB1. In this embodiment example, it applies that NB2=12.92 mm and NB1=12.58 mm. With the comparatively large groove depth NT =50 mm, comparatively large ratios of groove depth to groove width, namely 3.87 or 3.97, result therefrom. A groove depth of 52 mm can alternatively be provided. Even greater ratios of groove depth to groove width then result.

[0225] FIG. 8a shows, in an overview, different views of the pump system of the scroll vacuum pump according to FIGS. 3a and 3b, said pump system comprising the spiral housing of FIGS. 6a, 6b and 6c and the orbiter of FIGS. 7a and 7b. The pump system of the scroll vacuum pumps according to FIGS. 1a and 1b as well as FIGS. 2a and 2b is designed accordingly.

[0226] FIG. 8b shows the top-left representation (section A-A) of FIG. 8a in enlarged form. FIG. 8c shows the top-right representation (section B-B) of FIG. 8a in enlarged form. FIG. 8d shows the bottom-right representation (section C-C) of FIG. 8a in enlarged form.

[0227] In FIG. 8b, the cooperation of the spiral walls 49, 69 can be recognized that are inserted into one another and that sectionally enclose crescent-shaped or sickle-shaped volumes. During operation, incoming gas reaches the center of the pump system via the gas inlet 67, which is indicated in FIG. 8b only with respect to its position (cf. for example FIG. 7b), and reaches the outlet channel 59 via the inlet opening 55 if the outlet valve 56 (cf. for example FIG. 8d) opens at a sufficiently high pressure. The pumped gas reaches the radial outlet 57 and thus the outlet flange 78 via the outlet channel 59 if—as shown in FIG. 8d—the axial outlet opening 65 is closed by means of a plug 66.

[0228] As mentioned in the introductory part, in an alternative configuration, the radial outlet 57 can be closed and the plug 66 can be removed to create an axial outlet from the pump system in this way.

[0229] If an excess pressure is produced in the pump system during operation, it can be relieved by the pressure relief valves 61b, 63b in order to avoid an excessively high power consumption of the scroll vacuum pump. A particular feature of this arrangement is that a plurality of—here two—bypass channels 61, 63 are provided, each having exactly one pressure relief valve 61b or 63b. It is hereby achieved that the scroll vacuum pumps according to the invention have a relatively high pumping speed with a comparatively low power consumption.

[0230] FIG. 9 shows a concept that is referred to as a conical gap design and that can be provided in the scroll vacuum pumps according to the invention in accordance with the present disclosure, and indeed in the region where the spiral wall 49, extending in a spiral shape, of the stationary spiral component cooperates with the spiral wall 69, extending in a spiral shape, of the movable spiral component.

[0231] For each of the three states I, II and III of the scroll vacuum pump, in one development, the course of the movable spiral wall 69 in the pumping direction P is shown relative to the stationary spiral walls 49. In this respect, the upper stationary spiral wall 49 is in each case located radially further outwardly than the lower stationary spiral wall 49, which is indicated by the arrow r (radial direction).

[0232] The numerical values each indicate the radial distance (in mm) between the wall surfaces facing one another, i.e. the size of the radial gaps between the wall surfaces.

[0233] In state I, the scroll vacuum pump is not in operation, i.e. the drive shaft is not rotating and the orbiter, and thus its spiral wall 69, is stationary. The spiral housing and the orbiter are at ambient temperature.

[0234] The particular feature described here is that, in this initial state, the movable spiral wall 69 is arranged such that the gaps between the movable spiral wall 69 and the stationary spiral walls 49 each have a conical course in the pumping direction P.

[0235] In this respect, the course of the movable spiral wall 69 is selected such that, when the scroll vacuum pump is running, i.e. during the operation, according to state II, the deformation of the movable spiral wall 69 reduces the conicity of the gaps, as can be seen from the distance values. In state II, the movable spiral wall 69 therefore extends almost parallel to the two stationary spiral walls 49. The deformation of the movable spiral wall 69 results from the higher temperatures and from the movement of the orbiter.

[0236] At an even higher rotational speed, for example at a rotational speed of the drive shaft of 1800 revolutions per minute, according to state III, the centrifugal forces cause the movable spiral wall 69 to approach the radially outer stationary spiral wall 49, which leads to a very small radial gap there.

[0237] FIG. 10 shows different external views of a scroll vacuum pump according to FIGS. 3a and 3b.

[0238] As already explained, the pump housing 41 is seated on the electronics housing 43 and is closed at the motor side by the motor cover 103 and at the oppositely disposed side by the hood 105. Furthermore, the outlet flange 78 and the inlet flange 77 are shown.

[0239] The particular feature of this pump housing 41 is that the inlet flange 77, also designated as the intake flange 77, is set back at this axial position with respect to the highest point of the pump housing 41. Installation height is hereby saved. This is particularly advantageous if an alternative flange, not shown, is used that is formed by an angle flange.

[0240] Such a set-back arrangement of the inlet flange 77 is also provided in the scroll vacuum pump according to FIGS. 2a and 2b. REFERENCE NUMERAL LIST11 stationary spiral component, spiral housing

[0242] 13 movable spiral component, orbiter

[0243] 15 axis of rotation

[0244] 17 drive shaft

[0245] 17a shoulder

[0246] 19 eccentric section

[0247] 21 motor rotor

[0248] 23 motor stator

[0249] 25 front support point (fixed bearing)

[0250] 27 rear support point (floating bearing)

[0251] 29 front balancing weight

[0252] 31 rear balancing weight

[0253] 33 sleeve element

[0254] 35 balancing section of the front balancing weight

[0255] 36 bore

[0256] 37 opening of the balancing section

[0257] 38 screw

[0258] 39 balancing section of the rear balancing weight

[0259] 39a bore

[0260] 39b blind hole

[0261] 40 circular cylinder section

[0262] 41 pump housing

[0263] 43 electronics housing

[0264] 43a housing part

[0265] 43b housing cover

[0266] 44 plug

[0267] 45 electronic equipment

[0268] 47 cooling projection

[0269] 49 spiral wall of the stationary spiral component

[0270] 50 spiral groove

[0271] 51 spiral base

[0272] 53 support

[0273] 55 inlet opening

[0274] 56 outlet valve

[0275] 56a opening

[0276] 57 outlet

[0277] 59 outlet channel

[0278] 61 bypass channel

[0279] 61a bypass opening

[0280] 61b pressure relief valve

[0281] 61c opening

[0282] 62 plug

[0283] 63 bypass channel

[0284] 63a bypass opening

[0285] 63b pressure relief valve

[0286] 63c opening

[0287] 64 bore

[0288] 65 axial outlet opening

[0289] 66 plug

[0290] 67 gas inlet of the pump system

[0291] 69 spiral wall of the movable spiral component

[0292] 70 spiral groove

[0293] 71 spiral base

[0294] 73 support

[0295] 75 sealing element

[0296] 76 end of the spiral wall

[0297] 77 inlet flange

[0298] 78 outlet flange

[0299] 79 gas ballast valve

[0300] 81 closing cover of the gas ballast valve

[0301] 82 rotary knob

[0302] 83 central screw

[0303] 85 positioning element, positioning pin

[0304] 87 pressure element

[0305] 89 corrugated bellows

[0306] 91 flange bearing

[0307] 93 thrust washer

[0308] 94 shim washer

[0309] 95 fan

[0310] 97 positioning pin

[0311] 99 corrugated spring

[0312] 101 radial incision as a marking

[0313] 103 motor cover

[0314] 105 hood

[0315] 107 foot

[0316] 109 manufacturing arrangement

[0317] NT groove depth

[0318] NB1 groove width

[0319] NB2 groove width

[0320] WD1 thickness of the spiral wall

[0321] WD2 thickness of the spiral wall

[0322] E plane

[0323] P pumping direction

[0324] r radial direction

Claims

1-74. (canceled)75. A scroll vacuum pump, comprisinga pump system that comprises a stationary spiral component and a movable spiral component cooperating with said stationary spiral component in a pump-active manner;a drive shaft that rotates about an axis of rotation during operation and that has an eccentric section for driving the movable spiral component; andan electric drive motor for the drive shaft,wherein the drive shaft is provided with a front balancing weight and with a rear balancing weight, andwherein the front balancing weight and the rear balancing weight differ from one another with respect to materials from which they are made.

76. The scroll vacuum pump according to claim 75,wherein the material of the one balancing weight has a greater density than the material of the other balancing weight.

77. The scroll vacuum pump according to claim 75,wherein the front balancing weight is made of brass and the rear balancing weight is made of steel.

78. A scroll vacuum pump comprisinga pump system that comprises a stationary spiral component and a movable spiral component cooperating with said stationary spiral component in a pump-active manner;a drive shaft that rotates about an axis of rotation during operation and that has an eccentric section for driving the movable spiral component; andan electric drive motor for the drive shaft,wherein the stationary spiral component comprises a spiral arrangement, which has spiral walls and a spiral base, and a support for the spiral arrangement,wherein, in the support, an outlet channel is formed that is formed by an inlet opening formed in the spiral base and that leads to an outlet of the support, andwherein, in the support, in addition to the outlet channel, at least two bypass channels are formed which each lead from a bypass opening formed in the spiral base to an outlet of the support and in each of which at least one pressure relief valve is arranged.

79. The scroll vacuum pump according to claim 78,wherein the two bypass channels each lead to the outlet channel.

80. The scroll vacuum pump according to claim 78,wherein exactly one pressure relief valve is arranged in each bypass channel.

81. The scroll vacuum pump according to claim 78,wherein the stationary spiral component is formed in one piece, and wherein a side of the support facing the movable spiral component forms the spiral base of the spiral arrangement.

82. The scroll vacuum pump according to claim 78,wherein the two bypass openings are arranged offset from one another in the peripheral direction.

83. The scroll vacuum pump according to claim 78,wherein the two bypass openings are arranged at different radial positions or at at least substantially the same radial position with respect to a center axis of the stationary spiral component, which center axis extends parallel to the axis of rotation of the drive shaft.

84. The scroll vacuum pump according to claim 78,wherein the inlet opening of the outlet channel is arranged radially further inwardly than both bypass openings with respect to a center axis of the stationary spiral component, which center axis extends parallel to the axis of rotation of the drive shaft.

85. The scroll vacuum pump according to claim 84,wherein the inlet opening of the outlet channel is arranged at least substantially on the center axis.

86. A scroll vacuum pump comprisinga pump system that comprises a stationary spiral component and a movable spiral component cooperating with said stationary spiral component in a pump-active manner;a drive shaft that rotates about an axis of rotation during operation and that has an eccentric section for driving the movable spiral component; andan electric drive motor for the drive shaft,wherein the stationary spiral component comprises a spiral arrangement, which has spiral walls and a spiral base, and a support for the spiral arrangement,wherein, in the support, an outlet channel is formed that leads from an inlet opening formed in the spiral base to an outlet of the support, andwherein, in the support, in addition to the outlet channel, at least two bypass channels are formed that each lead from a bypass opening formed in the spiral base to the outlet channel.

87. The scroll vacuum pump according to claim 86,wherein the outlet of the support comprises a radial outlet opening and the outlet channel comprises a radially extending channel section leading to the radial outlet opening.

88. The scroll vacuum pump according to claim 87,wherein both bypass channels lead to the radial channel section in each case.

89. The scroll vacuum pump according to claim 87,wherein a first of the bypass channels leads to the radial channel section and a second of the bypass channels leads to a further channel section of the outlet channel that leads from the inlet opening to the radial channel section.

90. The scroll vacuum pump according to claim 89,wherein the further channel section of the outlet channel extends parallel to a center axis of the stationary spiral component, which center axis extends parallel to the axis of rotation of the drive shaft.

91. The scroll vacuum pump according to claim 86,wherein at least one pressure relief valve is arranged in each of the bypass channels.

92. The scroll vacuum pump according to claim 76,wherein it is the front balancing weight whose material has a greater density.

93. The scroll vacuum pump according to claim 82,wherein the two bypass openings are arranged offset from one another in the peripheral direction by an angle of less than 180°.

94. The scroll vacuum pump according to claim 90,wherein the further channel section of the outlet channel lies on the center axis.

Images