Scroll vacuum pump and scroll vacuum pump system

Abstract

The invention relates, among other things, to a scroll vacuum pump with a pumping system, a drive shaft having an eccentric section for driving the pumping system, and an electric drive motor for the drive shaft, wherein at least two bearing points spaced apart from each other along the axis of rotation of the drive shaft are provided for the rotary bearing of the drive shaft, and wherein all bearing 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 scroll vacuum pump systems with multiple scroll vacuum pumps of different designs.

[0002] The scroll vacuum pumps each comprise a pumping system comprising a fixed spiral component and a movable spiral component that cooperates with the latter to pump effectively, a drive shaft that rotates about an axis of rotation during operation and has an eccentric section for driving the movable spiral component, and an electric drive motor for the drive shaft.

[0003] The invention relates to a scroll vacuum pump according to the preamble of claim 1.

[0004] For example, US 2022 / 034321 A1 discloses a scroll vacuum pump according to the preamble of claim 1. EP 3 153 708 A2, EP 3 617 511 A2, EP 3 647 599 A2 and US 2014 / 140877 A1 each show related scroll vacuum pumps.

[0005] It is an object of the invention to improve such scroll vacuum pumps.

[0006] A scroll pump is a positive displacement pump that compresses against atmospheric pressure and can be used, among other things, as a compressor. A scroll vacuum pump can be used to create a vacuum in a chamber connected to a gas inlet of the scroll vacuum pump.

[0007] Scroll vacuum pumps are also known as spiral vacuum pumps or spiral conveying devices. The pumping principle underlying a scroll vacuum pump is generally known from the state of the art and will therefore only be briefly explained below.

[0008] The pumping system of a scroll vacuum pump comprises two nested or interlocked, for example Archimedean, spiral cylinders, which are also referred to simply as spirals. Each spiral cylinder comprises at least one equidistant spiral wall with a support, in particular a plate-shaped support, provided on one end face of the spiral wall. The outer turns of the spiral cylinder, for example the two or three outermost turns of the spiral cylinder, can be formed by wall sections that are each at a constant distance from the center of the spirals in the circumferential direction. Even though these wall sections do not strictly speaking form spiral sections but circular sections, in the context of the present disclosure they are attributed to the spiral and referred to as turns of the spiral.

[0009] The spiral cylinders are nested in such a way that the two spiral cylinders enclose crescent-shaped or sickle-shaped volumes in sections. One of the two spirals is immobile or fixed in the pump housing, whereas the other spiral, along with its support, can be moved along a circular path via the eccentric section of the drive shaft. This is why this spiral, together with its support, is also called an orbiter. This movable spiral component thus performs a so-called centrally symmetric oscillation, which is also referred to as "orbiting" or "wobbling."A crescent-shaped volume enclosed between the spiral cylinders migrates increasingly inwards as the movable spiral component orbits within the spirals, whereby the process gas to be pumped is conveyed by means of the migrat-ing volume from a radially outer gas inlet of the pump system radially inwards to a gas outlet of the pump system located particularly in the centre of the spiral.

[0010] The eccentric drive, i.e. the drive shaft with the eccentric section, is located inside the housing of the scroll vacuum pump on the side of the carrier facing away from the orbiter's spiral and is usually surrounded in practice by a deformable sleeve, for example a corrugated bellows, which serves on the one hand to seal the drive from the intake area and on the other hand to prevent the orbiter from rotating, since otherwise, without a rotation lock, it could rotate on its own. To ensure this rotation lock, for example, the deformable sleeve can be connected to the carrier at a first end, whereas the second end of the deformable sleeve, opposite the first end, can be screwed to the housing base by means of several fastening elements inside the housing.

[0011] The assembly comprising the orbiter and the deformable sleeve (e.g. bellows) can be pre-assembled during pump assembly so that this assembly can then be inserted into the pump housing as a unit, whereupon the mentioned second end of the deformable sleeve can be screwed to the housing base using the fastening means.

[0012] The following aspects of the present disclosure can be combined with each other in any way, provided they do not contradict each other. These aspects are the aspects defined in the claims and aspects not independently claimed, as well as their further developments, also referred to as embodiments or exemplary embodiments, specified in the following description, including the description of the figures.

[0013] The above-mentioned object of the invention is achieved according to a fifth aspect of the present disclosure by the features of the characterizing part of claim 1.

[0014] According to the invention, the drive shaft is provided with a front balancing weight and a rear balancing weight, wherein the front balancing weight and the rear balancing weight differ from one another with regard to the material from which they are made.

[0015] The concept of using different materials for the balancing weights creates an additional parameter that can be varied to adapt the balancing weights to the respective conditions.

[0016] In a system of scroll vacuum pumps of different designs, for example, the available space for a balancing weight may vary due to different pump system sizes. However, this does not necessarily mean that a smaller installation space also requires a smaller balancing mass, as the required balancing mass depends on the properties of the entire rotating system. In other words, in such a scroll vacuum pump system, it may be necessary to accommodate a comparatively large balancing mass in a comparatively small installation space in order to meet the respective balancing requirements while avoiding or at least minimizing design adjustments.

[0017] By choosing 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.

[0018] Advantageous further developments can therefore provide for the material of one balancing weight to have a higher density than the material of the other balancing weight. In particular, it can be provided that the front balancing weight has the higher density. This allows pump systems of different sizes to be compensated for by balancing weights of different densities while maintaining the same dimensions of the remaining rotating system.

[0019] In particular, it can be provided that the front balancing weight is made of brass and the rear balancing weight is made of steel.

[0020] According to a first aspect of the present disclosure, which is not independently claimed, at least two bearing points spaced apart from one another along the axis of rotation are provided for the rotational mounting of the drive shaft, wherein all bearing 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.

[0021] In other words, the drive motor is located behind the bearings, meaning there is no longer a bearing behind the drive motor. This simplifies the assembly and replacement of the drive motor or 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 designed as an asynchronous motor is arranged between two bearings spaced apart along the axis of rotation.

[0022] 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 located on the rear end of the drive shaft.

[0023] In some embodiments, it can be provided that the drive motor is arranged at least partially, preferably completely, within the pump housing. In particular, the drive motor is surrounded by the pump housing in the circumferential direction over at least more than half of its axial length, preferably over its entire axial length.

[0024] In this case, the pump housing can be closed at its rear end by means of a separate motor cover. If the drive motor is not completely located within the pump housing, the motor cover can have a receiving space with an axial depth dimensioned such that this receiving space can accommodate a rear end of the drive motor that protrudes axially rearward from the pump housing.

[0025] According to preferred embodiments of this aspect of the present disclosure, the electric drive motor of the scroll vacuum pump may be an asynchronous motor.

[0026] Alternatively, the electric drive motor can be a synchronous motor.

[0027] In particular, the electric drive motor can be designed as an IPM motor (IPM = Internal Permanent Magnet).

[0028] It can also be provided that the drive motor is a synchronous reluctance motor.

[0029] According to a second aspect of the present disclosure, not independently claimed, a balancing weight is placed on the front side of the rear end of the drive shaft.

[0030] One advantage of this balancing weight arrangement is that no additional space needs to be provided elsewhere. Another advantage is that the balancing weight can perform one or more additional functions in addition to balancing the rotating system. In particular, the balancing weight mounted on the front side can be used to clamp the drive motor rotor.

[0031] The rotating balancing weight creates air turbulence in the engine compartment, which can create a cooling effect and at least contribute to cooling the drive motor. This eliminates the need for cooling fins on the motor rotor, allowing the space freed up in the engine compartment to be used for the balancing weight.

[0032] "Attached" does not necessarily mean that the balancing weight touches the drive shaft. The balancing weight is located behind the drive shaft and is connected to the drive shaft in such a way that it rotates with the drive shaft during operation.

[0033] The balancing weight can, for example, be screwed to the drive shaft.

[0034] To screw the balancing weight to the drive shaft, a central screw can be provided, the shaft of which coincides with the axis of rotation.

[0035] According to some embodiments, it can be provided that the positioning of the balancing weight in the circumferential direction relative to the drive shaft is predetermined by a positioning aid.

[0036] The positioning aid can comprise a positioning element arranged at a radial distance from the rotational axis, as well as a positioning receptacle for a portion of the positioning element, wherein the positioning element is arranged on the drive shaft and the positioning receptacle is formed on the balancing weight, or vice versa. The positioning element can, for example, be pin-shaped and extend parallel to the rotational axis.

[0037] During assembly, the positioning element can be inserted axially into a recess. 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 that is non-rotatably connected to the motor rotor of the drive motor on the other.

[0038] According to some 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 on the rear end of the drive shaft.

[0039] According to some embodiments, it can be provided that the drive motor comprises a radially inner motor rotor, which is pushed onto the drive shaft directly or by means of a radially inner sleeve element that is connected to the motor rotor in a rotationally fixed manner, in particular with a clearance fit, wherein a form-fitting connection effective in the circumferential direction is provided between the motor rotor and the sleeve element on the one hand and the drive shaft on the other hand.

[0040] The positive connection can be formed by a positioning element of a positioning aid, which determines the circumferential positioning of the balancing weight relative to the drive shaft. The positioning element and / or the positioning aid can be the positioning element or the positioning aid described above.

[0041] According to some embodiments, the motor rotor of the drive motor can be provided with a radially inner sleeve element that is connected to the motor rotor in a rotationally fixed manner and with which the motor rotor is pushed onto the drive shaft, in particular with a loose fit. The sleeve element can be the sleeve element described above.

[0042] According to a third aspect of the present disclosure, not independently claimed, 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 connected to the motor rotor in a rotationally fixed manner and with which the motor rotor is pushed onto the drive shaft, in particular with a clearance fit.

[0043] The sleeve element is in particular the sleeve element described above.

[0044] With such a sleeve element, the inner diameter of the motor rotor can be adapted to the outer diameter of the relevant section of the drive shaft. This can be advantageous, for example, in a system with several scroll vacuum pumps of different designs that differ from one another in terms of the inner diameter of the motor rotor. In particular, this makes it possible to use one drive shaft for different motor rotors.

[0045] The sleeve element can be made of one or more parts.

[0046] The motor rotor and the sleeve element can be pressed together.

[0047] Furthermore, the sleeve element can be provided with a circumferential shoulder against which the motor rotor rests. This shoulder can form a support for the motor rotor, which can be clamped between this support and a clamping element. The clamping element can, for example, be mounted on the front side of the rear end of the drive shaft.

[0048] In particular, the clamping element may be a balancing weight, in particular the balancing weight described above.

[0049] Furthermore, the drive shaft can be provided with a circumferential shoulder against which the sleeve element rests. The shoulder of the drive shaft can form a support for the sleeve element when it is clamped during assembly. For example, the sleeve element can be clamped between this support and a clamping element placed on the front side of the rear end of the drive shaft. The clamping element can be, for example, a balancing weight, in particular the balancing weight described above.

[0050] According to a fourth aspect of the present disclosure, which is not independently claimed and relates to a scroll vacuum pump system having a plurality of scroll vacuum pumps of different designs, the drive shafts of the different scroll vacuum pumps are of identical construction.

[0051] This results in an advantageous reduction in the number of different components, since the same drive shaft can be used for the different scroll vacuum pumps.

[0052] For example, the scroll vacuum pumps can differ from one another with regard to the inner diameter of a radially inner motor rotor of the drive motor, whereby sleeve elements with different wall thicknesses are provided to adapt the drive shafts to the different inner diameters, each of which is arranged between the drive shaft and the motor rotor.

[0053] It can be provided that the motor rotors are each connected to the sleeve element in a rotationally fixed manner and are pushed onto the drive shaft with the sleeve element, in particular with a clearance fit.

[0054] It can be provided that the motor rotor and the sleeve element are pressed together.

[0055] According to a sixth aspect of the present disclosure, which is not independently claimed and relates to a scroll vacuum pump system comprising a plurality of scroll vacuum pumps of different designs, the scroll vacuum pumps differ in terms of the pumping system, wherein the drive shaft is provided with a front balancing weight and a rear balancing weight, and wherein the scroll vacuum pumps differ from one another in terms of the front balancing weight and / or the rear balancing weight.

[0056] According to a seventh aspect of the present disclosure, which is not independently claimed, the drive shaft is provided with at least one balancing weight, wherein the balancing weight comprises a plurality of balancing sections which are arranged successively along a longitudinal axis, which in the installed state runs parallel to the axis of rotation of the drive shaft, each of which has a partial ring shape and surrounds the drive shaft with its opening facing the latter, and wherein the balancing sections differ from one another with regard to the width of their openings.

[0057] By using a balancing weight with such different balancing sections, the available installation space can be optimally utilized.

[0058] The balancing weight having the different balancing sections can be the front balancing weight of the drive shaft, which also has a rear balancing weight.

[0059] In some embodiments, it can be provided that in the installed state the opening widths of the balancing sections increase in the direction of the pump system.

[0060] Furthermore, it can be provided that, in the installed state, a balancing section is arranged relative to the axis of rotation of the drive shaft at the level of the eccentric section of the drive shaft.

[0061] The opening of each balancing section can be defined in a plane perpendicular to the longitudinal axis by a pitch circle with a radius constant along the longitudinal axis, wherein the openings of the balancing sections differ from one another with regard to the size of the radii.

[0062] Preferably, the partial circles are not arranged concentrically.

[0063] The partial circles can each cover an angle in the range of 120° to 180°, in particular in the range of 150° and 170°.

[0064] The balancing weight can be made in one piece. This makes it possible to machine the balancing weight from a single workpiece.

[0065] Furthermore, it can be provided that the centers of all partial circles of at least two point sections, in particular of all point sections, lie in a plane in which the bisectors of the angles encompassed by the partial circles also lie.

[0066] According to an eighth aspect of the present disclosure, not independently claimed, the drive shaft is provided with at least one balancing weight comprising at least one balancing section which widens conically radially outwards in a plane perpendicular to a longitudinal axis which, in the installed state, runs parallel to the axis of rotation of the drive shaft.

[0067] With regard to the series production of scroll vacuum pumps and the resulting need for a correspondingly large number of balancing weights, the conical shape of the balancing weight enables material and cost optimization. The conical shape enables an imaginary rosette-like arrangement of several balancing sections around a central axis, which means that the circular surface and thus the material of a circular disk-shaped starting workpiece can be optimally utilized, thus achieving a high packing density of balancing weights in the workpiece. The proportion of unused material for the production of the balancing weights can thus be minimized.

[0068] The longitudinal axis may coincide with the rotational axis. The balancing section may be provided with a V-shaped expansion, thus defining an opening angle in the range of 10° to 30°, particularly in the range of 15° to 25°.

[0069] In a projection along the rotation axis, the outline of the balancing section can be delimited by two V-shaped straight lines diverging radially outward, 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 circular section lies and whose center preferably lies on the longitudinal axis can lie entirely within the outline of the balancing section. Alternatively or additionally, an imaginary circle on which the radially outer circular section lies can completely contain the outline of the balancing section.

[0070] Such designs of the balancing section can further increase the material yield.

[0071] According to some embodiments, the balancing weight may comprise a plurality of successive balancing sections along a longitudinal axis, which, when installed, runs parallel to the rotational axis of the drive shaft. In a projection along the longitudinal axis, the outline of the entire balancing weight is formed by the outline of the balancing section that widens conically radially outward. This ensures that the additional balancing section(s) do not impair the material yield.

[0072] At least one additional balancing section can be provided, which is shortened in the radial direction compared to the balancing section that widens conically outward and is otherwise congruent with the latter and aligned so as to overlap. This can further simplify the production of the balancing weight.

[0073] The balancing weight may have a circular cylindrical section that forms the front end of the balancing weight along the longitudinal axis and whose central axis coincides with the longitudinal axis. In particular, it may be provided that the thickness of the circular cylindrical section measured along the longitudinal axis is smaller than the thickness of each balancing section.

[0074] The circular cylindrical section can, for example, serve to center the balancing weight during assembly. In particular, the balancing weight can be inserted into a sleeve element with the circular cylindrical section, particularly in those embodiments in which the balancing weight is placed on the rear end of the drive shaft, with a motor rotor being connected in a rotationally fixed manner to the sleeve element and being pushed onto the drive shaft with the sleeve element.

[0075] The balancing weight can be placed with the circular cylinder section on the front side of the rear end of the drive shaft.

[0076] The balancing weight may have its greatest thickness measured along the longitudinal axis in the extension of the drive shaft.

[0077] In particular, the balancing weight may be constructed in one piece. This one-piece design further simplifies the production of the balancing weight.

[0078] According to a ninth aspect of the present disclosure, which is not independently claimed and relates to a system with 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 separate from the pump housing and is connected to the pump housing, in particular detachably, wherein the electronics housing comprises a housing part and electronics equipment, wherein the scroll vacuum pumps differ from one another with regard to the electronics equipment, and wherein the housing parts of the different scroll vacuum pumps are structurally identical.

[0079] Different electronics configurations can, for example, result from the scroll vacuum pumps being equipped with different drive motors. Different drive motors may require different electronic, electrical, and / or electromechanical components and / or a different number of such components.

[0080] The use of one housing part for different electronic equipment is equivalent to a modular system for the different scroll vacuum pumps, which simplifies production and thus reduces costs.

[0081] The housing parts can each be designed as a cast part.

[0082] The fact that the housing parts of the various scroll vacuum pumps are structurally identical does not preclude the possibility, according to advantageous developments, of different housing parts differing from one another with regard to post-processing to adapt them to the respective electronic equipment. Post-processing can, for example, consist of adapting one or more openings to the geometry of connectors or cables of the electronic equipment that are to be accommodated on the housing part or routed through a wall of the housing part. Post-processing can also consist, for example, in completely or partially removing existing walls within the housing part by milling in order to adapt the available installation space to the respective space requirements of the electronic equipment.

[0083] According to a tenth aspect of the present disclosure not independently claimed, 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 the axial direction.

[0084] This represents a departure from a conventional design characterized by such cooling projections being present on both end faces of the motor rotor. According to this aspect of the present disclosure, the cooling projections are provided only on one end face, which advantageously saves axial installation space. It has been surprisingly found that cooling projections provided only on one side can provide a sufficient cooling effect.

[0085] In some embodiments, at least some of the cooling projections may be designed and arranged such that they each act as a balancing weight. These balancing weights can collectively form an effective balancing mass with respect to the rotational axis. It has surprisingly been found that, with only one-sided arrangement of these projections, both a sufficient cooling effect and a sufficient balancing effect can be achieved.

[0086] It can be provided that it is the rear end of the motor rotor that is provided with the cooling projections. The front end of the motor rotor, which is not provided with such projections, can thus be arranged further inward than in a motor rotor that is provided with such projections on its front end.

[0087] The cooling projections can be rib-shaped or plate-shaped.

[0088] It can be provided that the cooling projections have at least two different sides that differ from one another in terms of their width, wherein the cooling projections are arranged such that the wider side points at least substantially in the circumferential direction and the narrower side points at least substantially in the radial direction. As a result, the cooling projections can generate comparatively strong air movements in the manner of blades, i.e., provide a comparatively strong "whirling or stirring effect," which promotes heat dissipation and thus the cooling effect. The cooling projections can be curved such that they point with a concave side at least substantially in the circumferential direction, specifically in the direction of rotation of the motor rotor. This can further increase the blade effect of the cooling projections.

[0089] According to a non-independently claimed eleventh aspect of the present disclosure, the fixed spiral component comprises a spiral arrangement with spiral walls and spiral base and a carrier for the spiral arrangement, wherein an outlet channel leading from an inlet opening formed in the spiral base to an outlet of the carrier is formed in the carrier, and wherein in addition to the outlet channel, at least two bypass channels are formed in the carrier, each leading from a bypass opening formed in the spiral base to an outlet of the carrier and in each of which at least one pressure relief valve is arranged.

[0090] The provision of a bypass channel with one or more pressure relief valves in the pumping system of a scroll vacuum pump is generally known. Overpressure, which occurs in certain pumping applications and would otherwise lead to particularly high pump power consumption, can be avoided in this way.

[0091] It was surprisingly found that several bypass channels, each with one or more pressure relief valves, enable a further improvement in that a comparatively high suction capacity is achieved with relatively low power consumption.

[0092] In some designs, the bypass channels may each lead to the outlet channel. In this case, one or more additional outlets for the bypass channels are not required.

[0093] Preferably, exactly two bypass channels are provided. It has been found that even two bypass channels are sufficient to achieve a particularly favorable ratio of power consumption to suction capacity.

[0094] According to further embodiments, it can be provided that exactly one pressure relief valve is arranged in each bypass channel. It has been found that one pressure relief valve per bypass channel is sufficient to achieve a particularly favorable ratio of power consumption to pumping capacity.

[0095] Preferably, the fixed spiral component is formed in one piece, wherein the side of the carrier facing the movable spiral component forms the spiral base of the spiral arrangement.

[0096] In some embodiments, it can be provided that the two bypass openings are arranged offset from one another in the circumferential direction, in particular by an angle of less than 180°, preferably by an angle between 90° and 180°.

[0097] Furthermore, it can be provided that the two bypass openings are arranged at different radial positions or at least substantially the same radial position with respect to a central axis of the fixed spiral component running parallel to the axis of rotation of the drive shaft.

[0098] Furthermore, it can be provided that the inlet opening of the outlet channel is arranged radially further inward than both bypass openings with respect to a central axis of the stationary spiral component running parallel to the axis of rotation of the drive shaft. In particular, the inlet opening of the outlet channel can be arranged at least substantially on the central axis.

[0099] According to a twelfth aspect of the present disclosure, not independently claimed, the fixed scroll component comprises a scroll arrangement having scroll walls and scroll base, and a support for the scroll arrangement, wherein an outlet channel is formed in the support leading from an inlet opening formed in the scroll base to an outlet of the support, and wherein in addition to the outlet channel, at least two bypass channels are formed in the support, each leading from a bypass opening formed in the scroll base to the outlet channel.

[0100] By having 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 carrier.

[0101] It can be provided that the outlet of the carrier comprises a radial outlet opening and the outlet channel comprises a radially extending channel section leading to the radial outlet opening.

[0102] It can be provided that both bypass channels lead to the radial channel section.

[0103] Alternatively, it can be provided that one bypass channel leads to the radial channel section and the other bypass channel leads to a further channel section of the outlet channel, which leads from the inlet opening to the radial channel section.

[0104] It can be provided that the further channel section of the outlet channel runs parallel to a central axis of the fixed spiral component running parallel to the axis of rotation of the drive shaft and in particular lies on the central axis.

[0105] According to some embodiments, it can be provided that at least one pressure relief valve is arranged in each of the bypass channels.

[0106] According to a thirteenth aspect of the present disclosure, not independently claimed, the fixed scroll component comprises a scroll arrangement having scroll walls and scroll base, and a support for the scroll arrangement, wherein an outlet channel is formed in the support leading from an inlet opening formed in the scroll base to an outlet of the support, and wherein the outlet of the support comprises an axial outlet opening.

[0107] The axial outlet opening is particularly advantageous if the outlet is to be used for another function that requires additional installation space. For example, it may be desired to integrate an additional device, such as a leak detector, into the scroll vacuum pump. This device must be connected to the carrier's outlet. With a conventional radial outlet opening, this additional function would require additional radial installation space, which is often not available. In contrast, an axial installation space can be implemented without any disadvantages in many cases. An additional device, such as a leak detector, can therefore be connected to the carrier's axial outlet opening without requiring additional radial installation space. This allows the scroll vacuum pump to be designed more slenderly.

[0108] Accordingly, in some embodiments, it may be provided that a vacuum device is connectable or connected to the axial outlet opening, wherein the vacuum device may in particular be a leak detection device.

[0109] The outlet channel may comprise a radially extending channel section and at least one further channel section leading from the radially extending channel section to the axial outlet opening.

[0110] The further channel section can run parallel to a central axis of the fixed spiral component that runs parallel to the axis of rotation.

[0111] In some embodiments, the outlet of the carrier may comprise a radial outlet opening in addition to the axial outlet opening, wherein the two outlet openings can be selectively closed so that the carrier can be operated with only a single outlet opening. This allows the scroll vacuum pump to be operated flexibly. The outlet opening not required at a time can be closed, for example, by means of a plug. To insert and remove such a plug, an opening can be formed in surrounding components, for example a hood, through which the respective outlet opening or a plug temporarily closing it is accessible.

[0112] The outlet channel can comprise a radially extending channel section leading to the radial outlet opening, with a further channel section leading to the axial outlet opening from a branch point of the radial channel section located between the inlet opening and the radial outlet opening. It can be provided that a channel section, which originates from a bypass opening formed in the spiral base, leads to a junction point, in particular located between the inlet opening and the branch point leading to the axial outlet opening.

[0113] The axial outlet opening can be formed in a radially outer region of the carrier. In particular, the radial position Ra of the axial outlet opening can be Ra > 0.5 * r, in particular Ra > 0.7 * r, in particular Ra > 0.8 * r, if r is the radius of the carrier.

[0114] According to a fourteenth aspect of the present disclosure, not independently claimed, the movable scroll component comprises a scroll arrangement with scroll walls, spiral grooves defined by these and a spiral base forming the bottom thereof, as well as a support for the scroll arrangement that cooperates with the eccentric section of the drive shaft, and the fixed scroll component comprises a scroll arrangement with scroll walls, spiral grooves defined by these and a spiral base forming the bottom thereof, as well as a support for the scroll arrangement, wherein the spiral grooves have a groove depth measured from the tip of the spiral walls to the spiral base along a central axis of the movable scroll component running parallel to the rotational axis of the drive shaft, and a groove width measured perpendicular to the central axis, and wherein in the movable scroll component and / or in the fixed scroll component, the ratio of groove depth to groove width is in a range of 3.7 to 4.2,in particular from 3.8 to 4.1, particularly 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.

[0115] With such dimensions of the spiral grooves, the pump system can achieve a comparatively high suction capacity.

[0116] Preferably, the ratio of groove depth to groove width is constant over the entire spiral arrangement.

[0117] The groove depth can be 50 mm, for example. Alternatively, the groove depth can be 52 mm. This results in even higher groove depth-to-width ratios, for example, in the range of 4.0 to 4.2, with the same groove width.

[0118] According to a fifteenth aspect of the present disclosure, not independently claimed, the movable scroll component comprises a scroll arrangement with scroll walls, spiral grooves delimited by them and a scroll base forming the bottom thereof, as well as a support for the scroll arrangement that cooperates with the eccentric section of the drive shaft, and the fixed scroll component comprises a scroll arrangement with scroll walls and a scroll base, as well as a support for the scroll arrangement, wherein in the movable scroll component and / or in the fixed scroll component, one or more radially outer scroll walls have a thickness that is greater than the thickness of radially further inner scroll walls.

[0119] The increased thickness allows for greater stability of the radially outer spiral wall(s). This is particularly advantageous if the spiral wall in question is interrupted in the circumferential direction.

[0120] According to some embodiments, it can be provided that the carrier is provided with a gas inlet in a radially outer region, in the region of which the spiral wall or the spiral walls are interrupted in the circumferential direction, wherein at least one, preferably each, of the spiral walls interrupted in the circumferential direction is provided with the greater thickness.

[0121] The gas inlet can comprise a recess starting from the outer edge of the carrier, preferably extending radially inwards in a V-shape, or can be formed by such a recess.

[0122] According to some embodiments, it may be provided that the or each spiral wall of greater thickness lies on a circle.

[0123] Furthermore, it can be provided that several, in particular two, radially outermost spiral walls of greater thickness lie on concentric circles, are interrupted in the circumferential direction in the region of a gas inlet formed in the carrier and delimit a parallel pumping structure of parallel pumping circular or circular segment-shaped channels, which merge into a helical pumping channel which is delimited by at least one helical spiral wall of smaller thickness.

[0124] According to a sixteenth aspect of the present disclosure, which is not independently claimed, the movable spiral component comprises a spiral arrangement with spiral walls, spiral grooves delimited by them and a spiral base forming the base thereof, as well as a support for the spiral arrangement which cooperates with the eccentric section of the drive shaft, wherein the stationary spiral component comprises a spiral arrangement with spiral walls and a spiral base, as well as 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 the case of one spiral wall, the sealing element is guided up to the end of the spiral wall which reaches a gas inlet of the pumping system.

[0125] For manufacturing reasons, it has been avoided to date to make such sealing elements long enough to extend to this end of the spiral wall. For example, an end section of the spiral wall covering an angular range of approximately 180° remained without a sealing element. Surprisingly, it has been discovered that a significant improvement in the pumping speed of the scroll vacuum pump is achieved when the sealing element is extended to the end of the spiral wall.

[0126] In some embodiments, the sealing element may be elongated in shape and extend continuously from a radially outer end to a radially inner end.

[0127] It can be provided that the sealing element has a length of more than 150 cm, in particular of approximately 160 cm.

[0128] The sealing element may consist of a thermoplastic material, in particular PTFE (polytetrafluoroethylene), or comprise such a material.

[0129] Preferably, the sealing element is received in a groove of the respective spiral wall.

[0130] The gas inlet of the pumping system can comprise a recess formed on the support of the movable spiral component. In particular, the recess can extend from the outer edge of the support and preferably radially inward in a V-shape.

[0131] The invention is described below by way of example with reference to the drawings. They show: Fig. 1a and 1b show an embodiment of a scroll vacuum pump according to the invention of a first type with a three-phase asynchronous motor, Fig. 2a and 2b show an embodiment of a scroll vacuum pump according to the invention of a second type with a three-phase asynchronous motor, Fig. 3a and 3b show an embodiment of a scroll vacuum pump according to the invention of a third type with an IPM motor, Fig. 3c, 3d and 3e show various views to explain embodiments of a balancing system according to the invention in connection with the scroll vacuum pump according to Fig. 3a and 3b , 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 Fig. 1a and 1b , Fig. 5a and 5b each show the electronics housing of a scroll vacuum pump according to the invention, namely Fig. 5a the electronics housing of a scroll vacuum pump Fig. 3a and 3b , and Fig. 5b the electronics housing of a scroll vacuum pump Fig. 1a and 1b or Fig. 2a and 2b , Fig. 6a, 6b and 6c different views of an embodiment of a fixed spiral component of a scroll vacuum pump according to the invention, Fig. 7a and 7b embodiment of a movable spiral component for the fixed spiral component of the Fig. 6a , 6b and 6c , Fig. 8a, 8b, 8c and 8d different views to explain the pump system with the fixed spiral component according to Fig. 6a , 6b and 6c and the movable spiral component Fig. 7a and 7b , Fig. 9 a schematic representation to explain the relative arrangement between the fixed spiral component and the movable spiral component in different states of an embodiment of a scroll vacuum pump according to the invention, and Fig. 10 various external views of a scroll vacuum pump according to the invention according to Fig. 2a and 2b or Fig. 3a and 3b .

[0132] The Fig. 1a and 1b , Fig. 2a and 2b as well as Fig. 3a and 3b The scroll vacuum pumps according to the invention shown are part of a scroll vacuum pump system comprising several scroll vacuum pumps of different designs. The scroll vacuum pumps in this system differ from one another in several respects but have the same basic design, which is described below.

[0133] Each scroll vacuum pump comprises a pumping system with a stationary scroll component 11 and a movable scroll component 13, which cooperate to pump during operation. Furthermore, each scroll vacuum pump comprises a drive shaft 16 that rotates about a rotational axis 15 during operation and has an eccentric section 19 for driving the movable scroll component 13. Furthermore, each scroll vacuum pump is provided with an electric drive motor 21, 23, which serves to rotate the drive shaft 17 about the rotational axis 15. The electric drive motor comprises a radially inner motor rotor 21 and a radially outer motor stator 23.

[0134] In each scroll vacuum pump, the drive shaft 17 is rotatably mounted on the pump housing 41 at two axially spaced bearing points 25, 27. The front roller bearing 25 is designed as a fixed bearing, while the rear roller bearing 27 is designed as a floating bearing.

[0135] A special feature of all scroll vacuum pumps in the system is the use of an arrangement known as the cantilever concept, whereby the two bearing points 25, 27 are located on the side of the drive motor 21, 23 facing the eccentric section 19 of the drive shaft 17. All bearing points 25, 27 are thus located within the pump housing 41 in front of the drive motor 21, 23. The eccentric section 19 is integrally connected to the front end of the drive shaft 17, and the drive motor 21, 23 is mounted on the rear end of the drive shaft 17.

[0136] Due to this basic structure, the drive motor 21, 23 can be pushed onto the rear end of the drive shaft 17, which simplifies the assembly and replacement of the drive motor or parts of the drive motor.

[0137] The balancing concept for balancing the rotating system comprising, among other things, the drive shaft 17 and the movable spiral component 13 comprises, in each scroll vacuum pump disclosed here, a front balancing weight 29 fastened to the drive shaft 17 by means of a screw 38 and a rear balancing weight 31. The front balancing weight 29 is arranged in the area of ​​the front end of the drive shaft 17 and the eccentric section 19. In the pump according to Fig. 1a and 1b The rear balancing weight 31 is located in front of the rear bearing 27 and thus in front of the drive motor. In the scroll vacuum pumps according to Fig. 2a and 2b as well as Fig. 3a and 3b According to one aspect of the scroll vacuum pumps of this type, the rear balancing weight 31 is formed by a pressure element which is placed on the rear end of the drive shaft 17. Also in the scroll vacuum pump according to Fig. 1a and 1bis a pressure element 87 ( Fig. 1b ), which is rotationally symmetrical and therefore does not serve as a balancing weight.

[0138] The pressure elements 87 and 31 are each connected to the drive shaft 17 by a central screw 83. As a result, the motor rotor 21 is clamped between the rotationally symmetrical pressure element 87 and the pressure element 31, which simultaneously serves as a balancing weight, on the one hand, and an abutment, said abutment being formed by a shoulder 17a formed on the drive shaft 17.

[0139] A further special 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 construction. Despite different motor sizes within the system, only one drive shaft 17 is required for the system. The drive motors of the scroll vacuum pumps of different designs differ, among other things, in the inner diameter of the radially inner motor rotor 21. This is demonstrated, for example, by the comparison of Fig. 2b and Fig. 3b . To adapt the identical drive shafts 17 to the different inner diameters of the motor rotors 21, sleeve elements 33 with different wall thicknesses are provided, which are each arranged between the drive shaft 17 and the motor rotor 21. In the scroll vacuum pump according to Fig. 2b Such a sleeve element 33 is provided, whereas the scroll vacuum pump according to Fig. 3b does not have such a sleeve element. In those scroll vacuum pumps that do have such a sleeve element 33, this is connected in a rotationally fixed manner to the respective motor rotor 21, whereby this connection between motor rotor 21 and sleeve element 33 is established by pressing. Thus, the pressed-together unit comprising motor rotor 21 and sleeve element 33 can be pushed onto the rear end of the drive shaft 17 during assembly. A clearance fit is present between the sleeve element 33 and the drive shaft 17.

[0140] In the area of ​​the mentioned shoulder 17a, a wave spring is arranged between the sleeve element 33 and the loose bearing 27.

[0141] A pin-shaped positioning element 85 serves as a positioning aid for the respective pressure element 87 or 31, as an anti-twist device when tightening the central screw 83, and as a positive connection effective in the circumferential direction between the motor rotor 21 or the sleeve element 33 on the one hand, and the drive shaft 17 on the other. 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 assembly, the positioning pin 85 can be pushed axially into a recess which is formed jointly by the drive shaft 17 on the one hand and the motor rotor 21 or the sleeve element 33 which is connected in a rotationally fixed manner to the motor rotor 21. In the assembled state, the positioning pin 85 projects axially to the rear and is received with its rear end in a positioning receptacle which is arranged on the side of the pressure element 87 or 31 facing the rear end of the drive shaft 17.31 is designed as a blind hole.

[0142] The mentioned clamping of the motor rotor 21 by means of the pressure element 87 or 31 is effected by the pressure element 87 or 31 being brought into contact with the axially rear end of the sleeve element 33 (cf. Fig. 1a and 1b as well as Fig. 2a and 2b ) or with the motor rotor 21 (cf. Fig. 3a and 3b ) interacts.

[0143] As an assembly aid when pressing the sleeve element 33 into the motor rotor 21, a radial recess 101 is provided at the front end of the motor rotor 21 in the assembled state, which serves as a marking for the assembler and thus indicates the installation orientation of the motor rotor 21.

[0144] For scroll vacuum pumps according to Fig. 2a and 2b as well as Fig. 3a and 3bThe drive motor is arranged completely within the pump housing 41, ie the drive motor is surrounded by the pump housing 41 in the circumferential direction over its entire axial length. At its rear end, the pump housing 41 is closed by a separate motor cover 103. A special feature of the scroll vacuum pumps according to Fig. 2a and 2b as well as Fig. 3a and 3b is that the motor covers 103 are identical despite different motor sizes. In the scroll vacuum pump according to Fig. 3a and 3b the drive motor is smaller than in the scroll vacuum pump according to Fig. 2a and 2b The pump housing 41 accordingly has a greater radial wall thickness in this area. For both pump types, the identical motor cover 103 can be screwed onto the rear end of the motor housing 41.

[0145] Another special feature is that the engine cover 103 is laser-engraved (not shown). This facilitates variable design compared to printing.

[0146] With the scroll vacuum pump according to Fig. 1a and 1b The drive motor is not completely arranged within the pump housing 41. The motor cover 103 has a receiving space that has an axial depth dimensioned such that the rear end of the drive motor, which protrudes axially rearward from the pump housing 41, is accommodated in this receiving space.

[0147] This scroll vacuum pump also provides that the motor rotor 21 is provided with cooling projections 47 projecting in the axial direction on its rear end face. A special feature here is that these cooling projections 47 are arranged only on this rear end face of the motor rotor 21, and the front end face of the motor rotor 21 does not have such cooling projections. This advantageously saves axial installation space. The cooling projections 47 are designed such that they each act as a balancing weight.

[0148] This aspect of the present disclosure will be discussed again elsewhere.

[0149] At the front end of the pump housing 41 is the pump system with the fixed spiral component 11 and the movable spiral component 13. The fixed spiral component 11, also referred to as the spiral housing, is screwed onto the front end of the pump housing 41 and is surrounded by a hood 105, which is also attached to the pump housing 41 and in which a fan 95 is also housed.

[0150] A special feature of the scroll vacuum pump system is that it features a set of 95 fans with different performance levels, yet they have the same dimensions. Fans 95 are available not only with a 24V supply voltage, but also with a supply voltage of, for example, 48V or 230V. This increases the system's variability.

[0151] The movable spiral component 13 is connected to the eccentric section 19 via a flange bearing 91 designed as a rolling bearing. A thrust washer 93 is located axially between the movable spiral component 13 and the eccentric section 19. A shim 94 is located between a circumferential shoulder of the drive shaft 17 at the transition to the eccentric section 19 and the flange bearing 91. The correct alignment in the circumferential direction between the stationary spiral component 11 and the pump housing 41 is ensured by a positioning pin 97.

[0152] For each scroll vacuum pump of the system, the pump housing 41 is supported on a base formed by an electronics housing 43. The electronics housing 43 comprises a housing part 43a, which is provided on its underside with rubber feet 107, which are received in recesses formed on the underside and are thus arranged countersunk.

[0153] The electronics housings 43 of the various scroll vacuum pumps differ, among other things, in the housing cover 43b that forms the lower cover of the housing part 43a. This will be discussed in more detail elsewhere.

[0154] Each electronics housing 43 houses an electronics unit 45 comprising electronic, electrical, and electromechanical components that serve, among other things, to supply power and control 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 regard to the electronics unit 45.

[0155] A special feature of the scroll vacuum pump system according to the invention is that the housing parts 43a of the different scroll vacuum pumps are structurally identical. The housing parts 43a are each formed as a cast part. Despite different electronic equipment 45 for the individual scroll vacuum pumps, only one housing part 43a is required.

[0156] This modular design reduces effort and costs in the manufacture of scroll vacuum pumps. The housing parts 43a differ slightly with regard to post-processing for adaptation to the respective electronic equipment 45. Such post-processing serves, for example, to adapt openings to the geometry of connectors or cables of the electronic equipment 45, which must be accommodated on the housing part or routed through a wall of the housing part. Furthermore, post-processing can consist of partially or completely removing the inner walls of a respective housing part 43a by milling in order to adapt the installation space available in the housing part 43a to the respective space requirements of the electronic equipment 45.

[0157] The pump housing 41 is screwed to the electronics housing 43.

[0158] In the Fig. 1a , 2a and 3aIn each case, the section BB at the bottom center shows the area of ​​the scroll vacuum pump where a gas ballast valve is located. The gas ballast valves 79 are designed differently for the individual scroll vacuum pumps. In the scroll vacuum pump according to Fig. 1a and 1b The gas ballast valve 79 is provided with a cover 81. In the scroll vacuum pumps according to Fig. 2a and 2b and 3a and 3b, the gas ballast valve 79 each has a rotary knob 82 for making adjustments.

[0159] The images in the top right corner of the Fig. 1a , 2a and 3a , each showing a view of the scroll vacuum pump onto the hood 105, the arrangement of an inlet flange 77 and the arrangement of an outlet flange 78 can be seen.

[0160] The gas to be pumped enters the pumping system comprising the two spiral components 11, 13 via the inlet flange 77 and is expelled via the outlet flange 78.

[0161] The two scroll vacuum pumps according to Fig. 1a and 1b and 2a and 2b are each equipped with a three-phase asynchronous motor 21, 23 for driving the drive shaft 17. The two scroll vacuum pumps differ, among other things, in their size. The pump system with the two spiral components 11, 13 and the asynchronous motor with rotor 21 and stator 23 in the scroll vacuum pump according to Fig. 1a and 1b a smaller diameter than the scroll vacuum pump Fig. 2a and 2b, whereby - as already mentioned - the two drive shafts 17 are identical in construction and thus have the same size. The diameter of the drive shaft 17 in the area of ​​the sleeve element 33 is 24 mm in this exemplary embodiment. To adapt the diameter of the drive shaft 17 in this area to the respective inner diameter of the motor rotor 21, the appropriately dimensioned sleeve element 33, which is pressed onto the motor rotor 21, serves - as already mentioned - to adapt it.

[0162] With the scroll vacuum pump according to Fig. 3a and 3b The pump system also has a diameter that is larger than the pump system of the scroll vacuum pump according to Fig. 1a and 1b However, the rotary drive for the drive shaft 17 is not an asynchronous motor, but a single-phase IPM motor (IPM = Internal Permanent Magnet).

[0163] 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 the rotary drive for the drive shaft 17.

[0164] The choice of a particular drive motor is made with regard to the desired performance, the targeted energy consumption as well as customer requirements and application conditions.

[0165] The modular principle provided according to the present disclosure is particularly advantageous with regard to this variability desired in practice due to its diverse adaptability.

[0166] As already mentioned, the balancing system for balancing the rotating system comprising in particular the drive shaft 17 and the movable spiral component 13 of the pumping system comprises a front balancing weight 29 and a rear balancing weight 31. In the scroll vacuum pump according to Fig. 1a and 1b the rear balancing weight 31 is located in front of the rear bearing point 27. The pressure element 87 for clamping the motor rotor 21 is designed to be rotationally symmetrical.

[0167] For scroll vacuum pumps according to Fig. 2a and 2b as well as Fig. 3a and 3bThe pressure element placed on the rear end of the drive shaft 17 simultaneously forms the rear balancing weight 31. Since in these two scroll vacuum pumps - as mentioned - the pump system has a larger diameter, the front balancing weight 29 is made of a material that has a higher density than the material of the rear balancing weight 31 due to the comparatively limited available installation space in the area of ​​the eccentric section 19 of the drive shaft 17. 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 Fig. 1a and 1b In contrast, the two balancing weights 29, 31 are made of the same material, namely steel.

[0168] As already mentioned in the introduction, the eccentric drive formed by the drive shaft 17 with the eccentric section 19 is located within the pump housing 41 and is surrounded by a deformable sleeve in the form of a bellows 89. The bellows 89 serves, on the one hand, to seal the eccentric drive from the suction area of ​​the scroll vacuum pump and, on the other hand, to prevent rotation of the movable spiral component 13. For this purpose, the bellows 89 is attached to the side of the movable spiral component 13 facing the drive. The rear end of the bellows 89 is attached to a housing base within the pump housing 41 by means of screws.

[0169] The balancing concept of the scroll vacuum pumps according to the invention is explained in more detail below, using the example of the scroll vacuum pump according to Fig. 3a and 3b These explanations also apply to the scroll vacuum pump according to Fig. 2a and 2band with regard to the front balancing weight 29 also for the scroll vacuum pump according to Fig. 1a and 1b .

[0170] Fig. 3c shows in sections perpendicular to the rotation axis 15 of the scroll vacuum pump Fig. 3a and 3b in the left illustration (section BB in Fig. 3b ) a view of the rear balancing weight 31 and in the right illustration (section AA in Fig. 3b ) the arrangement of a balancing section of the front balancing weight 39 in relation to the bellows 89, the flange bearing 91 and the eccentric section 19 of the drive shaft 17.

[0171] The specific design of the balancing weights 31, 29 is explained below in connection with the Fig. 3d and 3e discussed in more detail.

[0172] The left 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 conically radially outward. While maintaining the basic geometry of this rear balancing weight 31, it can be optimally adapted to different drive motors relatively easily during its manufacture.

[0173] As the right-hand illustration shows, the balancing section of the front balancing weight 29, shown in section, is partially annular in shape such that the inner radius is adapted to the outer radius of the flange bearing 91. This allows for optimal use of the available installation space.

[0174] The left illustration below shows a side view of the rear balancing weight 31. Among other things, the holes 39a for the central screw 83 and the blind hole 39b for receiving the positioning pin 85 are shown.

[0175] Fig. 3d shows in the two illustrations on the left the structure of the front balancing weight 39, which is formed 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.

[0176] The illustration on the right in Fig. 3d shows an enlarged section of the Fig. 3b the arrangement of the front balancing weight 29 in the area of ​​the eccentric section 19 of the drive shaft 17 and the flange bearing 91.

[0177] The balancing weight 29 comprises three balancing sections 35, which, when installed, follow one another along the rotational axis 15 of the drive shaft 17. Each balancing section 35 has a partial ring shape, with its opening 37 facing the drive shaft 17 and enclosing it when installed.

[0178] A special feature is that the balancing sections 35 differ from each other in terms of the width of their openings 37. This is evident from the perspective view at the top left in Fig. 3d as well as the top view at the bottom left in Fig. 3d can be found.

[0179] A further special 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 pitch circle with a radius constant along the central axis. A balancing section 35 with a radius R1, in the installed state, comprises a section 17b of the drive shaft 17, which lies immediately behind the eccentric section 19. The adjacent balancing section 35 with the radius R2 comprises the flange bearing 91. The third balancing section 35 is located in an axial region where the 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.

[0180] A special feature is that the two radii R1, R2 are not the same size and the two partial circles are not arranged concentrically, as can be seen in particular in the illustration below left in Fig. 3d can be seen. In the exemplary embodiment shown here, R1 = 22 mm and R2 = 28.3 mm, whereby the centers of the two pitch circles are offset from one another, but lie in plane E, in which the bisectors of the angles encompassed by the pitch circles lie. In the exemplary embodiment shown here, these angles are each 180°. The center of the rear balancing section 35 in the installed state lies on the axis of rotation 15, since this balancing section encompasses the central section 17b of the drive shaft 17. The other center of the pitch circle with the larger radius R2 lies accordingly outside the openings 37 of the balancing sections 35.

[0181] 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 encompassing the flange bearing 91 can be placed further radially outward than would be the case if the two centers coincided. In other words, a higher eccentric mass can be realized for this central balancing section 35 without increasing the outer dimensions of the balancing weight 29.

[0182] This advantageously ensures that the available installation space is optimally utilized and a sufficiently high balancing effect can be achieved.

[0183] Fig. 3e The left shows three views of the rear balancing weight 31, illustrating its construction. The balancing weight 31 is constructed in one piece.

[0184] The balancing weight 31 comprises two balancing sections 39 that flare conically outward. The balancing sections 39 each flare in a V shape, defining an opening angle of approximately 20°.

[0185] Furthermore, the balancing weight 31 comprises a circular cylinder section 40, the central axis of which, when installed, coincides with the rotational axis 15 of the drive shaft 17. The thickness of this circular cylinder section 40, measured along the rotational axis 15, is substantially smaller than the thickness of each balancing section 39. For example, Fig. 3b can be removed, the balancing weight 31 with its circular cylinder section 40 is facing the rear end of the drive shaft 17 when installed. The example of the scroll vacuum pump according to Fig. 2a and 2b It can be seen that the balancing weight 31 with its circular cylinder section 40 is inserted into the sleeve element 33.

[0186] The balancing section 39 located between the circular cylinder section 40 and the outer balancing section 39 is shortened in the radial direction compared to the outer balancing section 39, but is otherwise congruent with it and aligned so as to overlap. Both balancing sections 39 thus widen in a V-shape, i.e., in a projection along the rotation axis 15, the outlines of the two balancing sections 39 are delimited by two straight lines that diverge radially outwards in a V-shape. In addition, the two outlines of the balancing sections 39 are delimited by a radially inner circular section that has a smaller radius than a respective radially outer circular section, which forms the radially outer boundary of the respective outline.

[0187] This design of the rear balancing weight 31 allows for simple and cost-effective production as well as easy adaptation to the respective drive motor. However, adaptation is not absolutely necessary in every case. The rear balancing weight 31 can be designed in such a way that it can be used with the asynchronous motor of a scroll vacuum pump according to Fig. 2a and 2b , in particular with the sleeve element 33, as well as with the IPM motor of a scroll vacuum pump according to Fig. 3a and 3b can work together.

[0188] In the representations of the Fig. 3e The hole 39a for the central screw 83 and the blind hole 39b for the positioning pin 85 can also be seen.

[0189] As far as the production of the rear balance weight 31 is concerned, the conical shape allows for a minimization of material requirements. On the right in Fig. 3e For illustrative purposes, a manufacturing arrangement 109 is shown in which several balancing weights 31 are arranged in a rosette-like manner on a circle. This illustrates that a plurality of balancing weights 31 can be manufactured by cutting them from a flat material disc and subsequent individual machining.

[0190] Fig. 4 shows a view of the rear end of a scroll vacuum pump after Fig. 1a and 1b with the motor cover 103 removed. This shows the rear end face of the motor rotor 21, which is surrounded by a part of the motor stator 23.

[0191] As already mentioned elsewhere, a special feature here is that the motor rotor 21 is provided with axially projecting cooling projections 47 only on this rear end face. These cooling projections 47 are designed and arranged in such a way that they act as balancing weights. The balancing concept of the scroll vacuum pump according to Fig. 1a and 1b Thus, it includes not only the front balancing weight 91 and the rear balancing weight 31 arranged in front of the second bearing point 27, but also the balancing weights 47 arranged on the rear end face of the motor rotor 21, which also serve for cooling. These balancing weights or cooling projections 47 are plate-shaped and arranged such that their wider sides each point in the circumferential direction. As a result, the cooling projections 47 can generate comparatively strong air movements during operation, similar to blades, to promote heat dissipation.

[0192] The Fig. 5a shows the electronics housing 43 of the scroll vacuum pump Fig. 3a and 3b , whose drive motor is a single-phase IPM motor with an operating voltage of 24V / DC. The electronics include a Sub-D connector, a standby switch, an on / off switch, and USB ports.

[0193] Fig. 5b shows the electronics housing 43 of the scroll vacuum pumps Fig. 1a and 1b as well as Fig. 2a and 2b , each with a three-phase asynchronous motor as the drive motor. These asynchronous motors can operate with an operating voltage of up to 480V / AC.

[0194] Three-phase asynchronous motors require a higher protection class (especially IP44) than single-phase IPM motors, for which a lower protection class (especially IP40) is sufficient. These different protection classes result in different sealing concepts for the electronics housing 43.

[0195] In the electronics housing 43 for the scroll vacuum pump with single-phase IPM motor according to Fig. 5a A housing cover 43b, made of aluminum, for example, 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, with surfaces set back inward relative to the underside of a surrounding outer wall serving as a support for the housing cover 43b and each provided with a sealing material. Due to its recessed arrangement, the housing cover 43b is not visible from the side.

[0196] This is different for the electronics housing 43 for the scroll vacuum pumps with three-phase asynchronous motors. The housing cover 43b, made of aluminum, for example, is placed on the underside of the housing part 43a. The underside is—like the recessed support surfaces in the housing part 43a according to Fig. 5a - provided with a sealing material, wherein the inside of the housing cover 43b is additionally completely covered with a sealing material consisting, for example, of cellular rubber.

[0197] This provides a particularly effective seal for the electronics housing 43 in order to meet the requirements of the higher protection class.

[0198] As already mentioned elsewhere, the electronics housings 43 also differ in their respective electronic equipment 45. For example, the electronics housing 43 according to Fig. 5a provided with a connection for a cold appliance plug 44, to which a power supply unit for supplying power to the scroll vacuum pump can be connected. In contrast, the electronics housing 43 is Fig. 5b provided with a different mains plug 44, for example a mains plug of type Harting.

[0199] In addition, the electronics housing 43 differs according to Fig. 5b from the electronics housing 43 according to Fig. 5a by the absence of the Sub-D connector, the standby switch, the on / off switch, and the USB ports. The openings provided for this purpose in the housing component 43a are covered, for example, with a film. This allows for the electronics housing 43 to be Fig. 5b an IP protection class is possible.

[0200] Fig. 6a shows an overview of various views of a fixed spiral component 11, also referred to as a spiral casing, of a scroll vacuum pump according to the invention. The three upper views in Fig. 6a are enlarged in Fig. 6b shown, whereas the three lower representations of the Fig. 6a enlarged in Fig. 6c are shown.

[0201] Accordingly, Fig. 7a an overview with various representations of a movable spiral component 13, also referred to as orbiter, for the spiral casing 11 according to the Fig. 6a , 6band 6c .

[0202] The interaction of the spiral casing 11 and the orbiter 13 in the pumping system of a scroll vacuum pump according to the invention as well as the arrangement of the gas channels in the pumping system show the Fig. 8a , 8b , 8c and 8d .

[0203] The stationary spiral component 11 comprises a spiral arrangement with spiral walls 49 and spiral base 51, as well as a support 53 for the spiral arrangement. The two radially outer spiral walls 49 lie on concentric circles and are interrupted in the circumferential direction. This creates a parallel pumping structure consisting of parallel pumping channels formed by the respective spiral grooves 50, which merge into a helical pumping channel formed by a helical spiral groove 50 and delimited by a helical spiral wall 49.

[0204] The second, partially circular spiral wall 49, viewed from the radially outer side, has a greater thickness WD2 than the spiral-shaped spiral wall 49, which has a wall thickness WD1 in its radially inner direction. In this exemplary embodiment, WD2 = 3.71 mm and WD1 = 3.47 mm. The stability of the circumferentially interrupted circular spiral wall 49 is increased by this increased thickness WD2.

[0205] The spiral walls 49 are each provided at their end facing away from the spiral base 51 with an elongated sealing element 75, which is also referred to as a tip seal. The sealing element 75 for the radially outermost spiral wall 49 is comparatively long, as it continues to the further radially inner, spirally extending spiral wall 49 and reaches to the radially inner end of this spiral wall 49, located in the region of the central axis of the spiral casing 11. A special feature of this long sealing element 75 is that it is guided radially outward at the part-circular spiral wall 49 to the end 76 of this spiral wall 49, which ends at a gas inlet 67 (cf. Fig. 7a and 7b ) of the pumping system.

[0206] The gas pumped from radially outside to radially inside along the spiral grooves 50 can exit the spiral grooves 50 via a central inlet opening 55 and two bypass openings 61a, 63a into a channel system of the stationary spiral component 11, described in more detail below. 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 circumferential direction and are located on the same radius with respect to a central axis of the spiral casing 11.

[0207] Aligned with these openings 55, 61a, 63a are openings 56a, 61c, 63c formed on the side of the carrier 53 facing away from the spiral arrangement. These openings 56a, 61c, 63c serve to accommodate valves, which will be discussed in more detail elsewhere.

[0208] Furthermore, in this side of the carrier 53 facing away from the spiral arrangement, an axial outlet opening 65 is formed radially further outwards, which can optionally either be closed or form an axial gas outlet of the spiral housing 11 and thus of the pumping system of the scroll vacuum pump.

[0209] The mentioned openings communicate with a channel system of the spiral casing 11, which in the illustrations on the left and right in Fig. 6c is shown.

[0210] The central inlet opening 55 leads to an outlet channel 59 designed as a straight bore, which opens at the radial outlet 57 of the spiral casing 11. 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 also forms a bypass channel 63 for gas originating from the bypass opening 63a.

[0211] Another bypass channel 61 (see the right illustration in Fig. 6c ) leads from the further bypass opening 61c to the outlet channel 59. This bypass channel 61 is part of a straight bore 64 which is introduced to produce the bypass channel 61. This bore 64 and the outlet channel 69 extend at an angle to one another which corresponds to the angular offset of the two bypass openings 61c, 63c in the circumferential direction.

[0212] A further special feature of the pump system according to the invention, which is evident in both the spiral casing 11 and the orbiter 13, is that the groove depth NT is comparatively large. In the exemplary embodiment shown here, the groove depth is 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-shaped spiral groove 50 and with a groove width NB2 = 12.92 mm for a spiral groove 50 that runs radially further outwards and in a circle, the ratios are 3.93 and 3.87, respectively. A groove depth of 52 mm can be provided as an alternative. This then results in even larger ratios of groove depth to groove width.

[0213] The movable spiral component 13 according to Fig. 7a and 7balso includes a spiral arrangement with spiral walls 69 and spiral base 71, as well as a plate-shaped support 73 for the spiral arrangement. The two radially outer spiral walls 69 extend on concentric circles and are interrupted circumferentially in the region of a gas inlet 67. A radially inner spiral wall 69 extends spirally. 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.

[0214] In order to increase the stability of the two radially outer spiral walls 69 which are interrupted in the circumferential direction, these spiral walls 69 are designed with a thickness WD2 which is greater than the thickness WD1 of the spiral-shaped spiral wall 69. In this exemplary embodiment, WD2 = 3.71 mm and WD1 = 3.46 mm.

[0215] As shown in the illustration on the right in Fig. 7b As can be seen, the radially outer spiral groove 70 between the two part-circular spiral walls 69 has a groove width NB2, while the spiral-shaped spiral groove 70 delimited by the spiral spiral wall 69 has a groove width NB1. In this exemplary embodiment, NB2 = 12.92 mm and NB1 = 12.58 mm. With the comparatively large groove depth NT = 50 mm, this results in comparatively large ratios of groove depth to groove width, namely 3.87 and 3.97 respectively. A groove depth of 52 mm can be provided as an alternative. This then results in even larger ratios of groove depth to groove width.

[0216] Fig. 8a shows an overview of different views of the spiral casing of Fig. 6a , 6b and 6c and the orbiter of Fig. 7a and 7b comprehensive pumping system of the scroll vacuum pump Fig. 3a and 3b The pumping system of the scroll vacuum pumps according to Fig. 1a and 1b as well as Fig. 2a and 2b is trained accordingly.

[0217] Fig. 8b shows an enlarged view of the top left (section AA) of Fig. 8a . Fig. 8c shows an enlarged view of the top right (section BB) of Fig. 8a . Fig. 8d shows an enlarged view of the bottom right (section CC) of Fig. 8a .

[0218] In Fig. 8b The interaction of the interlocking spiral walls 49, 69 can be seen, which partially enclose crescent-shaped or sickle-shaped volumes. During operation, gas enters the chamber via the gas inlet 67, which is Fig. 8b only hinted at its position (see, for example, Fig. 7b ), inflowing gas to the center of the pumping system and via the inlet opening 55 into the outlet channel 59 when the outlet valve 56 (cf. e.g. Fig. 8d ) opens at sufficiently high pressure. The pumped gas passes through the outlet channel 59 to the radial outlet 57 and thus to the outlet flange 78, if - as in Fig. 8d shown - the axial outlet opening 65 is closed by means of a plug 66.

[0219] As mentioned in the introduction, in an alternative configuration, the radial outlet 57 can be closed and the plug 66 removed to create an axial outlet from the pumping system.

[0220] If excess pressure develops in the pumping system during operation, it can be relieved by the pressure relief valves 61b, 63b to prevent excessive power consumption of the scroll vacuum pump. A special feature of this arrangement is that several – here two – bypass channels 61, 63 are provided, each with exactly one pressure relief valve 61b or 63b. This ensures that the scroll vacuum pumps according to the invention have a relatively high pumping speed with comparatively low power consumption.

[0221] Fig. 9 shows a concept referred to as a conical gap design, which can be provided in the inventive scroll vacuum pumps according to the present disclosure, in the area where the spiral spiral wall 49 of the fixed scroll member interacts with the spiral spiral wall 69 of the movable scroll member.

[0222] For each of three states I, II, and III of the scroll vacuum pump, the course of the movable spiral wall 69 in the pumping direction P relative to the fixed spiral walls 49 is shown in a developed view. In each case, the upper fixed spiral wall 49 is located radially further outward than the lower fixed spiral wall 49, which is indicated by the arrow r (radial direction).

[0223] The numerical values ​​indicate the radial distance (in mm) between the facing wall surfaces, i.e. the size of the radial gap between the wall surfaces.

[0224] In state I, the scroll vacuum pump is not operating, meaning the drive shaft is not rotating and the orbiter, and thus its spiral wall 69, is stationary. The spiral casing and the orbiter are at ambient temperature.

[0225] The special 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 fixed spiral walls 49 each have a conical shape in the pumping direction P.

[0226] The path of the movable spiral wall 69 is selected such that, when the scroll vacuum pump is running, i.e., during operation, according to state II, the deformation of the movable spiral wall 69 reduces the conicity of the gap, as can be seen from the distance values. In state II, the movable spiral wall 69 thus runs almost parallel to the two fixed spiral walls 49. The deformation of the movable spiral wall 69 results from the higher temperatures and the movement of the orbiter.

[0227] At even higher speeds, for example at a drive shaft speed of 1,800 revolutions per minute, according to condition III, the centrifugal forces cause the movable spiral wall 69 to approach the radially outer fixed spiral wall 49, which leads to a very small radial gap there.

[0228] Fig. 10 shows various external views of a scroll vacuum pump according to Fig. 3a and 3b .

[0229] As already explained, the pump housing 41 sits on the electronics housing 43 and is closed on the motor side by the motor cover 103 and on the opposite side by the hood 105. Also shown are the outlet flange 78 and the inlet flange 77.

[0230] The special feature of this pump housing 41 is that the inlet flange 77, also referred to as the intake flange, is set back from the highest point of the pump housing 41 at this axial position. This saves installation height. This is particularly advantageous when an alternative flange (not shown) is used, which is formed by an angle flange.

[0231] Such a recessed arrangement of the inlet flange 77 is also used in the scroll vacuum pump according to Fig. 2a and 2b provided. Bezugszeichenliste

[0232] 11 Stationary scroll component, spiral casing 13 Movable scroll component, orbiter 15 Rotation axis 17 Drive shaft 17a Shoulder 19 Eccentric section 21 Motor rotor 23 Motor stator 25 Front bearing (fixed bearing) 27 Rear bearing (floating bearing) 29 Front balancing weight 31 Rear balancing weight 33 Sleeve element 35 Balancing section of the front balancing weight 36 Bore 37 Opening of the balancing section 38 Screw 39 Balancing section of the rear balancing weight 39a Bore 39b Blind hole 40 Circular cylinder section 41 Pump housing 43 Electronics housing 43a Housing part 43b Housing cover 44 Connector 45 Electronics equipment 47 Cooling projection 49 Spiral wall of the stationary Spiral component 50Spiral groove 51Spiral base 53Carrier 55Inlet opening 56Outlet valve 56aOpening 57Outlet 59Outlet channel 61Bypass channel 61aBypass opening 61bPressure relief valve 61cOpening 62Plug 63Bypass channel 63aBypass opening 63bPressure relief valve 63cOpening 64Bore 65Axial outlet opening 66Plug 67Gas inlet of the pump system 69Spiral wall of the movableScroll component 70Spiral groove 71Spiral base 73Support 75Sealing element 76End of the scroll wall 77Inlet flange 78Outlet flange 79Gas ballast valve 81Gas ballast valve cover 82Rotary knob 83Central screw 85Positioning element, positioning pin 87Thrust element 89Bellows 91Flange bearing 93Thrust washer 94Shim 95Fan 97Positioning pin 99Well spring 101Radial recess as marking 103Motor cover 105Cover 107Foot 109Manufacturing arrangement NT Groove depth NB1 Groove width NB2 Groove width WD1 Thickness of the spiral wall WD2 Thickness of the spiral wall E Plane PPumping direction r Radial direction

Claims

1. A scroll vacuum pump comprising - a pump system (11, 13) which comprises a stationary spiral component (11) and a spiral component (13) cooperating with said stationary spiral component (11) in a pump-active manner; - a drive shaft (17) which rotates about an axis of rotation (15) during operation and which has an eccentric section (19) for driving the movable spiral component (13); and - an electric drive motor (21, 23) for the drive shaft (17), wherein the drive shaft (17) is provided with a front balancing weight (29) and with a rear balancing weight (31), characterized in that the front balancing weight (29) and the rear balancing weight (31) differ from one another with respect to the material from which they are made.

2. A scroll vacuum pump according to claim 1, wherein the material of the one balancing weight (29) has a greater density than the material of the other balancing weight (31), in particular wherein it is the front balancing weight (29) whose material has a greater density.

3. A scroll vacuum pump according to claim 1 or 2, wherein the front balancing weight (29) is made of brass and the rear balancing weight (31) is made of steel.

Images