SCROLL VACUUM PUMP AND SCROLL VACUUM PUMP SYSTEM

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] Each scroll vacuum pump comprises a pumping system consisting of a stationary scroll element and a movable scroll element that interacts with it to perform the pumping action, a drive shaft rotating around a rotary axis during operation with an eccentric section for driving the movable scroll element, and an electric drive motor for the drive shaft. Scroll vacuum pumps are generally known, e.g., from EP 3 153 708 A2, EP 3 617 511 A2 and EP 3 647 599 A2.

[0003] US2022 / 034321 A1 discloses a scroll vacuum pump according to the preamble of claims 1 and 2.

[0004] The purpose of the invention is to improve such scroll vacuum pumps.

[0005] 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 receiver connected to a gas inlet of the scroll vacuum pump.

[0006] Scroll vacuum pumps are also known as spiral vacuum pumps or spiral conveying devices. The pumping principle underlying a scroll vacuum pump is fundamentally known from the prior art and is therefore only briefly explained below.

[0007] The pumping system of a scroll vacuum pump comprises two nested or interlocked spiral cylinders, for example, Archimedean spirals, which are also simply referred to as spirals. Each spiral cylinder includes at least one equidistant spiral wall with a support, in particular a plate-shaped support, provided at 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 circumferential distance from the center of the spirals. Even though these wall sections are strictly speaking not spiral sections but circular segments, in the context of this disclosure they are considered part of the spiral and referred to as turns of the spiral.

[0008] The spiral cylinders are nested inside each other in such a way that the two spiral cylinders partially enclose crescent- or sickle-shaped volumes. One of the two spirals is fixed within the pump housing, while 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 and its support are also referred to as the orbiter. This movable spiral component thus performs a so-called centrally symmetrical oscillation, which is also known as "orbiting" or "wobbling."A crescent-shaped volume enclosed between the spiral cylinders migrates increasingly inwards during the orbiting of the movable spiral component within the spirals, whereby the process gas to be pumped is conveyed by means of the migrating volume from a radially outer gas inlet of the pumping system to a radially inner gas outlet of the pumping system, which is located particularly in the center of the spiral.

[0009] The eccentric drive, i.e., the drive shaft with the eccentric section, is located inside the scroll vacuum pump housing on the side of the support facing away from the orbiter's spiral. In practice, it is usually surrounded by a deformable sleeve, such as a bellows. This sleeve serves both to seal the drive against the intake area and to prevent the orbiter from rotating, as it could otherwise spin freely without this anti-rotation device. To ensure this anti-rotation, the deformable sleeve can, for example, be connected to the support at one end, while the other end of the deformable sleeve, opposite the first end, can be screwed to the base of the housing inside using several fasteners.

[0010] 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, after which the aforementioned second end of the deformable sleeve can be screwed to the housing base with the fastening means.

[0011] The invention is defined in independent claims 1 and 2.

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

[0013] The aforementioned problem of the invention is solved according to a second and third aspect of the present disclosure by the features of the characterizing part of claim 1 and 2 respectively.

[0014] According to claim 1, the invention provides that the drive motor comprises a radially inner motor rotor and a radially outer motor stator, wherein the motor rotor is clamped between a support and the balancing weight mounted on the rear end of the drive shaft, and wherein the balancing weight serves to clamp the motor rotor.

[0015] According to claim 2, the invention provides that 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 fixed to the motor rotor and with which the motor rotor is pushed onto the drive shaft, in particular with a clearance fit, and wherein the sleeve element is clamped between an abutment and the balancing weight mounted as a clamping element on the rear end of the drive shaft.

[0016] One advantage of this arrangement of the balancing weight is that no additional installation space needs to be provided elsewhere. Another advantage is that the balancing weight can perform one or more additional functions besides balancing the rotating system. In particular, the front-mounted balancing weight serves to clamp the rotor of the drive motor.

[0017] The rotating balancing weight creates air turbulence in the engine compartment, which can have a cooling effect and at least contribute to cooling the drive motor. This eliminates the need for cooling fins on the motor rotor, freeing up space in the engine compartment for the balancing weight.

[0018] In this context, "mounted" 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 it in such a way that it rotates together with the drive shaft during operation.

[0019] The balancing weight can, for example, be bolted to the drive shaft. A central bolt, the shank of which coincides with the axis of rotation, can be provided for bolting the balancing weight to the drive shaft. According to some embodiments, the circumferential positioning of the balancing weight relative to the drive shaft can be predetermined by a positioning aid.

[0020] The positioning aid can comprise a positioning element arranged radially from the axis of rotation, as well as a positioning receptacle for a portion of the positioning element. The positioning element can be arranged on the drive shaft and the positioning receptacle formed on the balancing weight, or vice versa. The positioning element can, for example, be pin-shaped and extend parallel to the axis of rotation. 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 one side and a motor rotor of the drive motor, or by a radially inner sleeve element non-rotatably connected to the motor rotor of the drive motor, on the other.

[0021] According to claim 1, the drive motor comprises a radially inner motor rotor and a radially outer motor stator, wherein the motor rotor is clamped between a support and the balancing weight mounted on the rear end of the drive shaft. According to claim 2, 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 that is rotationally fixed to the motor rotor and with which the motor rotor is pushed onto the drive shaft, in particular with a clearance fit, and wherein the sleeve element is clamped between a support and the balancing weight mounted on the rear end of the drive shaft as a clamping element.

[0022] 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 in the inner diameter of their motor rotors. In particular, this makes it possible to use one drive shaft for different motor rotors. The sleeve element can be a single piece or multi-piece. The motor rotor and the sleeve element can be pressed together. 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 end face of the rear end of the drive shaft.In particular, the clamping element may be a balancing weight, especially the balancing weight described above.

[0023] Furthermore, the drive shaft may 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 mounted on the end face of the rear end of the drive shaft.

[0024] According to a first aspect of the present disclosure which is not independently claimed, at least two bearing points spaced apart from each other along the axis of rotation are provided for the rotary support 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.

[0025] In other words, the drive motor is located behind the bearings; that is, there are no bearings behind the drive motor. This simplifies the assembly and replacement of the drive motor or parts thereof, particularly the motor rotor or the assembly comprising the motor rotor. This concept represents a departure from a conventional arrangement in which a drive motor, designed as an asynchronous motor, is positioned between two bearings spaced apart along the axis of rotation.

[0026] According to some further developments, it may 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.

[0027] In some embodiments, the drive motor may be 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 for at least more than half of its axial length, preferably for its entire axial length.

[0028] The pump housing may be closed at its rear end by means of a separate motor cover. If the drive motor is not located entirely within the pump housing, the motor cover may have a receiving space with an axial depth dimensioned such that this receiving space can accommodate a rear end of the drive motor projecting axially rearward from the pump housing.

[0029] 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.

[0030] Alternatively, the electric drive motor can be a synchronous motor. In particular, the electric drive motor can be designed as an IPM motor (IPM = Internal Permanent Magnet).

[0031] It is also possible that the drive motor is a synchronous reluctance motor.

[0032] According to a fourth aspect of the present disclosure, which is not independently claimed and relates to a scroll vacuum pump system with several scroll vacuum pumps of different designs, the drive shafts of the different scroll vacuum pumps are identical in construction.

[0033] 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.

[0034] For example, scroll vacuum pumps can differ from each other with respect 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 arranged between the drive shaft and the motor rotor.

[0035] It may be provided that the motor rotors are each connected to the sleeve element in a rotationally fixed manner and pushed onto the drive shaft with the sleeve element, in particular with a clearance fit.

[0036] It may be provided that the motor rotor and the sleeve element are pressed together.

[0037] According to a fifth aspect of the present disclosure, which is not independently claimed, the drive shaft is equipped with a front

[0038] Balancing weight and provided with a rear balancing weight, wherein the front balancing weight and the rear balancing weight differ from each other in terms of the material from which they are made.

[0039] 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.

[0040] In a system of scroll vacuum pumps of different designs, the available installation space for a balancing weight can vary due to the different sizes of the pump systems. However, this does not necessarily mean that a smaller installation space requires a smaller balancing weight, as the required balancing weight depends on the characteristics of the entire rotating system. In other words, such a scroll vacuum pump system may require a relatively large balancing weight to be accommodated in a relatively small installation space in order to meet the specific balancing requirements while avoiding or at least minimizing design modifications.

[0041] By choosing a higher density material for one of the balancing weights, its mass can be increased without requiring more installation space for that balancing weight.

[0042] Advantageous further developments can therefore provide that the material of one balancing weight has a higher density than the material of the other balancing weight. In particular, it can be provided that the front balancing weight is made of a material with a higher density. This allows different sized pump systems to be compensated for by balancing weights of different densities, while the remaining rotating system has the same dimensions.

[0043] In particular, it may be provided that the front balancing weight is made of brass and the rear balancing weight is made of steel.

[0044] According to a sixth aspect of the present disclosure, which is not independently claimed and relates to a scroll vacuum pump system with several 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 each other with respect to the front balancing weight and / or the rear balancing weight.

[0045] According to a seventh aspect of the invention not claimed independently, the drive shaft is provided with at least one balancing weight, wherein the balancing weight comprises several successive balancing sections along a longitudinal axis which, in the installed state, runs parallel to the axis of rotation of the drive shaft, each having a partial ring shape and encompassing the drive shaft with their opening pointing towards it, and wherein the balancing sections differ from one another with respect to the width of their openings.

[0046] By using a balancing weight with such different balancing sections, the available installation space can be optimally utilized.

[0047] The balancing weight with the different balancing sections could be the front balancing weight of the drive shaft, which also has a rear balancing weight.

[0048] In some embodiments, it may be provided that, in the installed state, the opening widths of the balancing sections increase in the direction of the pump system.

[0049] Furthermore, it may be provided that, in the installed state, a balancing section is arranged at the height of the eccentric section of the drive shaft, relative to the axis of rotation of the drive shaft.

[0050] The opening of each balancing section can be defined in a plane perpendicular to the longitudinal axis by a partial circle with a radius constant along the longitudinal axis, whereby the openings of the balancing sections differ from each other with respect to the size of the radii.

[0051] Preferably, the partial circles are not arranged concentrically.

[0052] The partial circles can each encompass an angle in the range of 120° to 180°, particularly in the range of 150° and 170°.

[0053] The balancing weight can be manufactured in one piece. This makes it possible to produce the balancing weight from a single workpiece using machining.

[0054] Furthermore, it can be provided that the centers of all partial circles of at least two point segments, in particular of all point segments, lie in a plane in which the bisectors of the angles encompassed by the partial circles also lie.

[0055] According to an eighth aspect of the present disclosure which is not independently claimed, the drive shaft is provided with at least one balancing weight which comprises at least one balancing section which expands radially outwards in a conical manner in a plane perpendicular to a longitudinal axis which, in the installed state, runs parallel to the axis of rotation of the drive shaft.

[0056] With regard to the mass 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 allows for an imaginary rosette-like arrangement of several balancing sections around a central axis, which means that the circular area, and thus the material, of a circular disk-shaped workpiece is optimally utilized, effectively achieving a high packing density of balancing weights within the workpiece. The proportion of material unused in the production of the balancing weights can therefore be minimized.

[0057] The longitudinal axis can coincide with the axis of rotation. The balancing section can be designed to widen in a V-shape, thus defining an opening angle in the range of 10° to 30°, particularly in the range of 15° to 25°.

[0058] In a projection along the axis of rotation, the outline of the balancing section can be bounded by two V-shaped, radially outwardly diverging straight lines, a radially inner circular segment, and a radially outer circular segment. The radially inner circular segment can have a smaller radius than the radially outer circular segment. An imaginary circle on which the radially inner circular segment 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 circular segment lies can completely contain the outline of the balancing section.

[0059] Such designs of the balancing section can further increase the material yield.

[0060] According to some embodiments, the balancing weight may comprise several successive balancing sections along a longitudinal axis that, in the installed state, runs parallel to the axis of rotation 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 expands conically radially outwards. This ensures that the additional balancing section(s) do not impair the material yield.

[0061] At least one additional balancing section can be provided, which is shorter in the radial direction compared to the radially outwardly conical balancing section and is otherwise congruent to it and overlapping. This further simplifies the manufacturing of the balancing weight.

[0062] The balancing weight can have a circular cylinder segment that forms the end face of the balancing weight along its longitudinal axis and whose central axis coincides with the longitudinal axis. In particular, it can be provided that the thickness of the circular cylinder segment, measured along its longitudinal axis, is less than the thickness of each balancing segment.

[0063] The circular cylinder section can, for example, serve to center the balancing weight during assembly. In particular, the balancing weight can be inserted into a sleeve element along with the circular cylinder section, especially in those embodiments where the balancing weight is mounted face-up on the rear end of the drive shaft, with a motor rotor non-rotatably connected to the sleeve element and pushed onto the drive shaft along with the sleeve element.

[0064] The balancing weight can be attached to the rear end of the drive shaft, face down, using the circular cylinder section.

[0065] The balancing weight can have its greatest thickness, measured along the longitudinal axis, in the extension of the drive shaft.

[0066] In particular, the balancing weight can be designed as a single piece. This one-piece design further simplifies the manufacturing process.

[0067] According to a ninth aspect of the present disclosure, which is not independently claimed and relates to a system with several 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 housed in the pump housing and the electronics housing is a component separate from the pump housing, which is connected to the pump housing, in particular detachably, wherein the electronics housing comprises a housing part and an electronics assembly, wherein the scroll vacuum pumps differ from one another with respect to the electronics assembly, and wherein the housing parts of the different scroll vacuum pumps are identical in construction.

[0068] Different electronic configurations can result, for example, from 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.

[0069] Using a single housing component for different electronic configurations is equivalent to a modular system for the various scroll vacuum pumps, which simplifies manufacturing and thus reduces costs. The housing components can each be manufactured as a casting.

[0070] The fact that the housing components of the different scroll vacuum pumps are structurally identical does not preclude the possibility that, according to advantageous embodiments, the housing components of the different scroll vacuum pumps may differ with regard to post-processing to adapt them to the respective electronic components. This post-processing could, for example, consist of adapting one or more openings to the geometry of connectors or cables of the electronic components that are to be accommodated in the housing component or routed through a wall of the housing component. Post-processing could also, for example, consist of completely or partially removing existing walls within the housing component by milling in order to adapt the available installation space to the respective space requirements of the electronic components.

[0071] According to a tenth aspect of the present disclosure which is not claimed independently, 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 extending in the axial direction.

[0072] This represents a departure from a conventional design characterized by the presence of such cooling protrusions on both end faces of the motor rotor. By having the cooling protrusions on only one end face, as described in this aspect of the invention, axial installation space is advantageously saved. It was surprisingly found that cooling protrusions on only one end face are sufficient to provide adequate cooling.

[0073] In some embodiments, at least some of the cooling protrusions may be designed and arranged such that they each act as balancing weights. These balancing weights can then collectively form an effective balancing mass with respect to the axis of rotation. It was surprisingly found that with only one-sided arrangement of these protrusions, both a sufficient cooling effect and a sufficient balancing effect can be achieved.

[0074] It may be designed so that the rear end face of the motor rotor is provided with the cooling projections. The front end face of the motor rotor, which is not provided with such projections, can therefore be positioned further inwards than in a motor rotor that is provided with such projections on its front end face.

[0075] The cooling protrusions can be rib-shaped or plate-shaped.

[0076] The cooling projections can be designed to have at least two different sides that differ in width, with the wider side pointing at least substantially circumferentially and the narrower side at least substantially radially. This allows the cooling projections to generate relatively strong airflow, i.e., a relatively large "whirling or stirring effect," which promotes heat dissipation and thus the cooling effect. The cooling projections can be curved such that one concave side points at least substantially circumferentially, in the direction of rotation of the motor rotor. This further enhances the blade effect of the cooling projections.

[0077] According to an eleventh aspect of the present disclosure, which is not independently claimed, the stationary spiral component comprises a spiral arrangement with spiral walls and a spiral base, and a support for the spiral arrangement, wherein an outlet channel leading from an inlet opening formed in the spiral base to an outlet of the support is formed in 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 spiral base to an outlet of the support and in each of which at least one pressure relief valve is arranged.

[0078] 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. This prevents overpressure that can occur in certain pumping applications and would otherwise lead to particularly high power consumption by the pump.

[0079] It was surprisingly found that multiple 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.

[0080] In some advanced training programs, the bypass channels may be designed to lead directly to the outflow tract. In such cases, one or more additional outlets for the bypass channels are not required.

[0081] Preferably, exactly two bypass channels are provided. It has been found that two bypass channels are sufficient to achieve a particularly favorable ratio of power consumption to suction capacity.

[0082] 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 speed.

[0083] Preferably, the stationary spiral component is formed in one piece, with the side of the support facing the movable spiral component forming the spiral base of the spiral arrangement.

[0084] In some embodiments, the two bypass openings may be arranged offset from each other in the circumferential direction, in particular by an angle of less than 180°, preferably by an angle between 90° and 180°.

[0085] Furthermore, it may be provided that the two bypass openings are arranged at different radial positions or at least at substantially the same radial position with respect to a central axis of the stationary spiral component running parallel to the axis of rotation of the drive shaft.

[0086] Furthermore, it may be provided that the inlet opening of the exhaust channel is arranged radially further inwards 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 exhaust channel may be arranged at least substantially on the central axis.

[0087] According to a twelfth aspect of the present disclosure, which is not independently claimed, the stationary spiral component comprises a spiral arrangement with spiral walls and a spiral base, and a support for the spiral arrangement, wherein an outlet channel leading from an inlet opening formed in the spiral base to an outlet of the support is formed in the support, and wherein at least two bypass channels are formed in the support in addition to the outlet channel, each leading from a bypass opening formed in the spiral base to the outlet channel.

[0088] 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 support. The outlet of the support can be designed to include a radial outlet opening, and the outlet channel can include a radially extending channel section leading to this radial outlet opening.

[0089] It may be provided that both bypass channels lead to the radial channel section.

[0090] Alternatively, it can be provided that one bypass channel leads to the radial channel section and the other bypass channel leads to another channel section of the outlet channel, which leads from the inlet opening to the radial channel section.

[0091] It may be provided that the further channel section of the outlet channel runs parallel to a central axis of the stationary spiral component which runs parallel to the axis of rotation of the drive shaft and in particular lies on the central axis.

[0092] According to some embodiments, it may be provided that at least one pressure relief valve is arranged in each of the bypass channels.

[0093] According to a thirteenth aspect of the present disclosure which is not independently claimed, the stationary spiral component comprises a spiral arrangement with spiral walls and spiral base and a support for the spiral arrangement, wherein an outlet channel leading from an inlet opening formed in the spiral base to an outlet of the support is formed in the support, and wherein the outlet of the support comprises an axial outlet opening.

[0094] An axial outlet is particularly advantageous when the outlet is to be used for an additional function that requires extra installation space. For example, it may be desirable to integrate an additional device, such as a leak detector, into the scroll vacuum pump, which must be connected to the outlet of the carrier. With a conventional radial outlet, this additional function would require additional radial installation space, which is often unavailable. An axial outlet, on the other hand, can be implemented in many cases without any drawbacks. Consequently, an additional device, such as a leak detector, can be connected to the axial outlet of the carrier without requiring additional radial installation space. This allows the scroll vacuum pump to be designed with a more compact profile.

[0095] Accordingly, in some embodiments it may be provided that a vacuum device can be connected or is connected to the axial outlet opening, the vacuum device being in particular a leak detection device.

[0096] The outlet channel can 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.

[0097] The further channel section can run parallel to a central axis of the stationary spiral component that runs parallel to the axis of rotation.

[0098] In some embodiments, the carrier may include a radial outlet in addition to the axial outlet, with both outlets being selectively closable, allowing the carrier to be operated with only a single outlet. This enables flexible operation of the scroll vacuum pump. The outlet not currently in use can be closed, for example, with a plug. To insert and remove such a plug, an opening may be provided in surrounding components, such as a cover, through which the respective outlet or the plug temporarily closing it is accessible.

[0099] 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 also be provided that a channel section leading to a junction point, in particular located between the inlet opening and the branch point leading to the axial outlet opening, originates from a bypass opening formed in the spiral base.

[0100] The axial outlet opening can be formed on a radially outer region of the support. In particular, the radial position Ra of the axial outlet opening can be Ra > 0.5 * r, especially Ra > 0.7 * r, especially Ra > 0.8 * r, where r is the radius of the support.

[0101] According to a fourteenth aspect of the present disclosure, which is not claimed independently, the movable spiral component comprises a spiral arrangement with spiral walls, spiral grooves bounded by these walls and a spiral base forming the bottom of the spiral grooves, as well as a support for the spiral arrangement cooperating with the eccentric section of the drive shaft, and the stationary spiral component comprises a spiral arrangement with spiral walls, spiral grooves bounded by these walls and a spiral base forming the bottom of the spiral grooves, as well as a support for the spiral arrangement, wherein the spiral grooves have a groove depth measured from the apex of the spiral walls to the spiral base along a central axis of the movable spiral component extending parallel to the axis of rotation of the drive shaft, and a groove width measured perpendicular to the central 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 of 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.

[0102] With such dimensions of the spiral grooves, the pumping system can achieve a comparatively high suction speed.

[0103] Preferably, the ratio of groove depth to groove width is constant over the entire spiral arrangement.

[0104] The groove depth can be, for example, 50 mm. Alternatively, the groove depth can be 52 mm. This results in even higher ratios of groove depth to groove width – with the same groove width – which are, for example, in the range of 4.0 and 4.2.

[0105] According to a non-independently claimed fifteenth aspect of the present disclosure, the movable spiral component comprises a spiral arrangement with spiral walls, spiral grooves bounded by these walls and a spiral base forming their bottom, as well as a support for the spiral arrangement cooperating with the eccentric section of the drive shaft, and 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 in the movable spiral component and / or in the stationary spiral component one or more radially outer spiral walls have a thickness that is greater than the thickness of radially inner spiral walls.

[0106] The increased thickness allows for greater stability of the radially outer spiral wall(s). This is particularly advantageous when the spiral wall in question is interrupted in the circumferential direction.

[0107] According to some embodiments, the support may be provided with a gas inlet in a radially outer area, in the area of ​​which the spiral wall or spiral walls are interrupted in the circumferential direction, wherein at least one, preferably each, of the circumferentially interrupted spiral walls is provided with the greater thickness.

[0108] The gas inlet can comprise a recess extending radially inwards from the outer edge of the carrier, preferably in a V-shape, or be formed by such a recess.

[0109] According to some embodiments, it can be provided that the spiral wall or each spiral wall of greater thickness lies on a circle.

[0110] 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 area of ​​a gas inlet formed in the support and define a parallel pumping structure of parallel pumping circular or circular segment-shaped channels which transition into a helical pumping channel which is bounded by at least one helically extending spiral wall of smaller thickness.

[0111] 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 bounded by these walls and a spiral base forming their bottom, as well as a support for the spiral arrangement cooperating 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 extends to the end of the spiral wall reaching towards a gas inlet of the pump system.

[0112] For manufacturing reasons, it has been avoided until now to make such sealing elements long enough to extend to the very end of the spiral wall. For example, an end section of the spiral wall spanning an angle of approximately 180° has remained without a sealing element. It was surprisingly found that a significant improvement in the pumping speed of the scroll vacuum pump occurs when the sealing element extends to the very end of the spiral wall.

[0113] In some embodiments, the sealing element may be of an elongated shape and extend continuously from a radially outer end to a radially inner end.

[0114] It may be provided that the sealing element has a length of more than 150 cm, in particular of approximately 160 cm.

[0115] The sealing element can be made of a thermoplastic material, in particular PTFE (polytetrafluoroethylene), or comprise such a material.

[0116] Preferably, the sealing element is received in a groove of the respective spiral wall.

[0117] The gas inlet of the pump system can include a recess formed in the support of the movable spiral component. In particular, it can be provided that the recess extends from the outer edge of the support and preferably in a V-shape radially inwards.

[0118] The invention is described below by way of example with reference to the drawing. The drawing shows: Figs. 1a and 1b show an embodiment of a scroll vacuum pump of a first type according to the invention with a three-phase asynchronous motor; Figs. 2a and 2b show an embodiment of a scroll vacuum pump of a second type according to the invention with a three-phase asynchronous motor; Figs. 3a and 3b show an embodiment of a scroll vacuum pump of a third type according to the invention with an IPM motor; Figs. 3c, 3d and 3e show various views to illustrate embodiments of a balancing system according to the invention in conjunction with the scroll vacuum pump according to Fig. 3a and 3b , Fig. 4 shows an aspect of the invention relating to the balancing of the motor rotor, using the scroll vacuum pump as an example. Fig. 1a and 1b , Figs. 5a and 5b each show the electronic housing of a scroll vacuum pump according to the invention, namely Fig. 5a the electronic housing of a scroll vacuum pump after Fig. 3a and 3b , and Fig. 5b the electronic housing of a scroll vacuum pump after Fig. 1a and 1b or Fig. 2a and 2b Figs. 6a, 6b and 6c show different views of an embodiment of a stationary spiral component of a scroll vacuum pump according to the invention, Figs. 7a and 7b show an embodiment of a movable spiral component for the stationary spiral component of the Fig. 6a , 6b and 6c , Figs. 8a, 8b, 8c and 8d different views to illustrate the pump system with the stationary spiral component according to Fig. 6a , 6b and 6c and the movable spiral component Fig. 7a and 7b Fig. 9 shows a schematic representation to illustrate the relative arrangement between the stationary 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 shows various external views of a scroll vacuum pump according to the invention. Fig. 2a and 2b or Fig. 3a and 3b .

[0119] The in Fig. 1a and 1b , Fig. 2a and 2b as well as Fig. 3a and 3b The scroll vacuum pumps according to the invention, as illustrated, belong to a scroll vacuum pump system with several scroll vacuum pumps of different designs. The scroll vacuum pumps of this system differ from one another in several respects, but have the same basic structure, which is described below.

[0120] Each scroll vacuum pump comprises a pumping system with a stationary scroll element 11 and a movable scroll element 13, which interact to pump effectively during operation. Furthermore, each scroll vacuum pump includes a drive shaft 16 rotating about an axis of rotation 15 during operation, with an eccentric section 19 for driving the movable scroll element 13. Each scroll vacuum pump is also equipped with an electric drive motor 21, 23, which serves to rotate the drive shaft 17 about the axis of rotation 15. The electric drive motor comprises a radially inner motor rotor 21 and a radially outer motor stator 23.

[0121] The drive shaft 17 of each scroll vacuum pump is rotatably mounted on the pump housing 41 at two axially spaced bearing points 25, 27. The front rolling bearing 25 is designed as a fixed bearing, while the rear rolling bearing 27 is designed as a floating bearing.

[0122] A special feature of all scroll vacuum pumps in the system is a cantilever configuration, in which 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 located on the rear end of the drive shaft 17.

[0123] The drive motor 21, 23 can be pushed onto the rear end of the drive shaft 17 using this basic structure, which simplifies the assembly and replacement of the drive motor or parts of the drive motor.

[0124] The balancing concept for balancing the rotating system, which includes, among other things, the drive shaft 17 and the movable spiral component 13, comprises, in each scroll vacuum pump disclosed herein, a front balancing weight 29 and a rear balancing weight 31, both attached to the drive shaft 17 by means of a screw 38. The front balancing weight 29 is located 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 point 27 and thus in front of the drive motor. In the case of scroll vacuum pumps according to Fig. 2a and 2b as well as Fig. 3a and 3b According to one aspect of scroll vacuum pumps of this design, the rear balancing weight 31 is formed by a pressure element which is mounted on the end face of the rear end of the drive shaft 17. This also applies to the scroll vacuum pump according to... Fig. 1a and 1bis a pressure element 87 mounted on the front face of the rear end of the drive shaft 17 ( Fig. 1b ) provided, which, however, is rotationally symmetrical and therefore does not serve as a balancing weight.

[0125] The pressure elements 87 and 31 are each connected to the drive shaft 17 by a central screw 83. This clamps the motor rotor 21 between the rotationally symmetrical pressure element 87 or the pressure element 31, which also serves as a balancing weight, on the one hand, and a support, this support being formed by a shoulder 17a on the drive shaft 17.

[0126] Another 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 identical in construction. 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 differ, among other things, with regard to the inner diameter of the radially inner motor rotor 21. This is shown, for example, by comparing 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, each arranged between the drive shaft 17 and the motor rotor 21. In the scroll vacuum pump according to Fig. 2b A sleeve element 33 of this type is provided, whereas the scroll vacuum pump according to Fig. 3b no such sleeve element. In those scroll vacuum pumps that do have such a sleeve element 33, this element is rotationally fixed to the respective motor rotor 21, with this connection between the motor rotor 21 and the sleeve element 33 being made by crimping. Thus, the crimped unit consisting of the motor rotor 21 and the sleeve element 33 can be slid onto the rear end of the drive shaft 17 during assembly. A clearance fit exists between the sleeve element 33 and the drive shaft 17.

[0127] In the area of ​​the aforementioned shoulder 17a, a wave spring is arranged between the sleeve element 33 and the loose bearing 27.

[0128] A pin-shaped positioning element 85 serves as a positioning aid for the respective pressure element 87 or 31, as an anti-rotation device when tightening the central screw 83, and as a circumferentially effective positive-locking connection 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 inserted axially into a recess formed jointly by the drive shaft 17 on the one hand and the motor rotor 21 or the sleeve element 33, which is non-rotatably connected to the motor rotor 21, on the other. In the assembled state, the positioning pin 85 projects axially to the rear and is received at its rear end in a positioning receptacle located 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.

[0129] The 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 connected to 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 (see Fig. 3a and 3b ) works together.

[0130] As an assembly aid when pressing the sleeve element 33 into the motor rotor 21, a radial groove 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.

[0131] Regarding 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, i.e., 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 means of 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 The difference lies in the fact that the motor covers 103 are identical despite the different motor sizes. Regarding the scroll vacuum pump... 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.

[0132] Another special feature is that the engine cover 103 is laser engraved (not shown). This allows for more flexible design compared to printing.

[0133] Regarding the scroll vacuum pump after Fig. 1a and 1b The drive motor is not completely enclosed within the pump housing 41. The motor cover 103 has a receiving space with an axial depth dimensioned such that the rear end of the drive motor, projecting axially backwards from the pump housing 41, is received in this receiving space.

[0134] In this scroll vacuum pump, the motor rotor 21 is provided with axially projecting cooling projections 47 on its rear end face. A special feature 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 any such cooling projections. This advantageously saves axial installation space. The cooling projections 47 are designed to act as balancing weights.

[0135] This aspect of the invention will be discussed again elsewhere.

[0136] At the front end of the pump housing 41 is the pump system with the stationary spiral component 11 and the movable spiral component 13. The stationary 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.

[0137] A special feature of the scroll vacuum pump system is that it uses a set of 95mm fans with varying power outputs, all of which have the same dimensions. The system includes not only 95mm fans with a 24V supply voltage, but also those with supply voltages of, for example, 48V or 230V. This increases the system's versatility.

[0138] 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. Correct circumferential alignment between the stationary spiral component 11 and the pump housing 41 is ensured by a positioning pin 97.

[0139] In 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 that are received in recesses formed on the underside and are thus recessed.

[0140] The electronic housings 43 of the different scroll vacuum pumps differ, among other things, with regard to a housing cover 43b that forms the lower cover of the housing part 43a. This will be discussed in more detail elsewhere.

[0141] In Each electronic housing 43 contains an electronic assembly 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 respect to their electronic assembly 45.

[0142] 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 identical in construction. The housing parts 43a are each designed as a cast part. Consequently, despite different electronic configurations 45 for the individual scroll vacuum pumps, only one housing part 43a is required.

[0143] This modular design reduces effort and costs in the manufacture of the scroll vacuum pumps. The housing components 43a differ slightly with regard to post-processing for adaptation to the respective electronic components 45. Such post-processing serves, for example, to adapt openings to the geometry of connectors or cables of the electronic components 45, which must be accommodated in the housing component or routed through a wall of the housing component. Furthermore, post-processing can consist of partially or completely removing the inner walls of a respective housing component 43a by milling in order to adapt the available installation space in the housing component 43a to the respective space requirements of the electronic components 45.

[0144] The pump housing 41 is screwed to the electronics housing 43.

[0145] In the Fig. 1a , 2a and 3aIn section BB below, the area of ​​the scroll vacuum pump where a gas ballast valve is located is shown in the center. The gas ballast valves 79 are designed differently in the individual scroll vacuum pumps. In the scroll vacuum pump according to Fig. 1a and 1b The gas ballast valve 79 is equipped with a sealing cap 81. In the scroll vacuum pumps according to Fig. 2a and 2b In addition to 3a and 3b, the gas ballast valve 79 each has a rotary knob 82 for making adjustments.

[0146] The illustrations in the upper right corner in the Fig. 1a , 2a and 3a , which each show a view of the scroll vacuum pump on the hood 105, the arrangement of an inlet flange 77 and the arrangement of an outlet flange 78 can be seen in each case.

[0147] 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.

[0148] The two scroll vacuum pumps after Fig. 1a and 1b Components 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, wherein – as already mentioned – the two drive shafts 17 are identical in construction and therefore have the same size. In this embodiment, the diameter of the drive shaft 17 in the area of ​​the sleeve element 33 is 24 mm. 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.

[0149] Regarding the scroll vacuum pump after Fig. 3a and 3b The pump system also has a diameter that is larger than that of the scroll vacuum pump pump system 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).

[0150] 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.

[0151] 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.

[0152] The modular design principle provided according to the invention is particularly advantageous with regard to the variability desired in practice due to its diverse adaptability.

[0153] 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, includes a front balancing weight 29 and a rear balancing weight 31. In the scroll vacuum pump according to Fig. 1a and 1bThe 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.

[0154] Regarding scroll vacuum pumps according to Fig. 2a and 2b as well as Fig. 3a and 3bThe pressure element mounted on the end face of the rear end of the drive shaft 17 simultaneously forms the rear balancing weight 31. Since, as mentioned, the pump system in these two scroll vacuum pumps has a larger diameter, the front balancing weight 29 is made of a material with a higher density than the material of the rear balancing weight 31, due to the comparatively limited installation space available in the area of ​​the eccentric section 19 of the drive shaft 17. Accordingly, one aspect of the invention provides that the front balancing weight 29 is made of brass and the rear balancing weight 31 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.

[0155] As already mentioned in the introduction, the eccentric drive formed by the drive shaft 17 and the eccentric section 19 is located inside 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 against the intake area of ​​the scroll vacuum pump and, on the other hand, to prevent the movable spiral component 13 from rotating. 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 inside the pump housing 41 by means of screws.

[0156] The balancing concept of the scroll vacuum pumps according to the invention is explained in more detail below, using the scroll vacuum pump according to [reference to invention] as an example. Fig. 3a and 3b These explanations also apply to the scroll vacuum pump according to Fig. 2a and 2bas well as with regard to the front balancing weight 29 for the scroll vacuum pump according to Fig. 1a and 1b .

[0157] Fig. 3c shows in sections perpendicular to the axis of rotation 15 of the scroll vacuum pump Fig. 3a and 3b in the left-hand illustration (section BB in Fig. 3b ) a view of the rear balancing weight 31 and in the right-hand 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.

[0158] The specific design of the balancing weights 31, 29 will be described below in conjunction with the Fig. 3d and 3e discussed in more detail.

[0159] The left-hand representation in Fig. 3c This 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 described above, widens conically radially outwards. While maintaining the basic geometry of this rear balancing weight 31, it can be relatively easily adapted to different drive motors during its manufacture.

[0160] As the illustration on the right shows, the balancing section of the front balancing weight 29, shown in cross-section, is partially ring-shaped such that the inner radius is adapted to the outer radius of the flange bearing 91. This ensures optimal use of the available installation space.

[0161] The left-hand illustration below shows the rear balancing weight 31 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.

[0162] Fig. 3d The two illustrations on the left show the construction of the front balancing weight 39, which is formed in one piece and - as mentioned above - can be made of different materials, in particular materials of different density such as brass on the one hand and steel on the other.

[0163] 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.

[0164] The balancing weight 29 comprises three balancing sections 35, which, in the installed state, follow one another along the axis of rotation 15 of the drive shaft 17. Each balancing section 35 has a partial ring shape, with each balancing section, in the installed state, having its opening 37 facing and encompassing the drive shaft 17.

[0165] One special feature is that the balancing sections 35 differ from each other in the width of their openings 37. This is evident both from the perspective view in the upper left. Fig. 3d as well as the top view below left in Fig. 3d to be taken.

[0166] Another special feature of this front balancing weight 29 is that the opening 37 of each balancing section 35 in a plane E perpendicular to the axis of rotation 15 (in the installed state) is defined by a pitch circle with a constant radius along the central axis. In the installed state, a balancing section 35 with radius R1 encompasses a section 17b of the drive shaft 17, which lies immediately behind the eccentric section 19. The adjacent balancing section 35 with radius R2 encompasses the flange bearing 91. The third balancing section 35 is located in an axial area 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 and R2 of the other two balancing sections.

[0167] One special feature is that the two radii R1 and R2 are not the same size, and furthermore, the two partial circles are not arranged concentrically, as can be seen in particular in the illustration below left in Fig. 3d can be extracted. In the embodiment shown here, R1 = 22 mm and R2 = 28.3 mm, with the centers of the two pitch circles offset from each other, but lying in the plane E in which the bisectors of the angles encompassed by the pitch circles lie. These angles are each 180° in the embodiment shown here. 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.

[0168] 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 positioned further radially outwards than would be the case if the two centers coincided. In other words, a higher eccentric mass can be achieved for this central balancing section 35 without increasing the outer dimensions of the balancing weight 29.

[0169] This advantageously ensures that the available installation space is optimally utilized and a sufficiently high balancing effect can be achieved.

[0170] Fig. 3e Figure 31 on the left shows three views of the rear balancing weight 31, illustrating its construction. The balancing weight 31 is manufactured in one piece.

[0171] The balancing weight 31 comprises two balancing sections 39 that widen conically radially outwards. Each balancing section 39 widens in a V-shape, defining an opening angle of approximately 20°.

[0172] Furthermore, the balancing weight 31 comprises a circular cylinder section 40, the central axis of which, in the installed state, coincides with the axis of rotation 15 of the drive shaft 17. The thickness of this circular cylinder section 40, measured along the axis of rotation 15, is significantly smaller than the thickness of any balancing section 39. For example Fig. 3b When installed, the balancing weight 31, with its circular cylinder section 40, faces the rear end of the drive shaft 17. (Following the example of the scroll vacuum pump...) 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.

[0173] The balancing section 39, located between the circular cylinder segment 40 and the outer balancing section 39, is shortened in the radial direction compared to the outer balancing section 39, but is otherwise congruent to it and overlapping. Both balancing sections 39 thus extend in a V-shape; that is, in a projection along the axis of rotation 15, the outlines of the two balancing sections 39 are bounded by two V-shaped straight lines diverging radially outwards. Furthermore, the outlines of the two balancing sections 39 are bounded by a radially inner circular segment, which has a smaller radius than a respective radially outer circular segment that forms the radial outer boundary of the respective outline.

[0174] This design of the rear balancing weight 31 allows for simple and cost-effective manufacturing as well as easy adaptation to the respective drive motor. However, adaptation is not always absolutely necessary. The rear balancing weight 31 can be designed in such a way that it is compatible with both 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.

[0175] In the depictions of the Fig. 3e The bore 39a for the central screw 83 and the blind hole 39b for the positioning pin 85 can also be seen.

[0176] Regarding the manufacture of the rear balancing weight 31, the conical shape allows for a minimization of material requirements. Right in Fig. 3e For illustrative purposes, a manufacturing arrangement 109 is shown in which several balancing weights 31 are arranged in a rosette pattern on a circle. This illustrates that a plurality of balancing weights 31 can be manufactured by cutting them from a flat disc of material and then machining them individually.

[0177] Fig. 4 shows a view of the rear end of a scroll vacuum pump. Fig. 1a and 1b with the motor cover 103 removed. This reveals the rear end face of the motor rotor 21, which is surrounded by part of the motor stator 23.

[0178] As mentioned elsewhere, a special feature here is that the motor rotor 21 is only provided with axially projecting cooling protrusions 47 on this rear end face. These cooling protrusions 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 This includes not only the front balancing weight 91 and the rear balancing weight 31 located in front of the second bearing 27, but also the balancing weights 47 located on the rear end face of the motor rotor 21, which simultaneously serve for cooling. These balancing weights, or cooling projections 47, are plate-shaped and arranged such that their wider side points circumferentially. This allows the cooling projections 47 to generate relatively strong air currents during operation, similar to blades, to promote heat dissipation.

[0179] The Fig. 5a The electronics housing 43 of the scroll vacuum pump shows Fig. 3a and 3b , whose drive motor is a single-phase IPM motor with an operating voltage of 24V / DC. The electronic equipment 45 includes a Sub-D connector, a standby switch, an on / off switch, and USB ports.

[0180] Fig. 5b The electronic housing 43 of the scroll vacuum pumps shows Fig. 1a and 1b as well as Fig. 2a and 2b , each featuring a three-phase asynchronous motor as its drive motor. These asynchronous motors can be operated with an operating voltage of up to 480V / AC.

[0181] Three-phase asynchronous motors require a higher protection class (especially IP44) than the single-phase IPM motor, for which a lower protection class (especially IP40) is sufficient. These different protection classes result in different concepts for sealing the electronics housing 43.

[0182] The electronic housing 43 for the scroll vacuum pump with single-phase IPM motor according to 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, whereby surfaces recessed inwards from the underside of a surrounding outer wall serve as a bearing for the housing cover 43b and are each provided with a sealing material. Due to its recessed arrangement, the housing cover 43b is not visible from the side.

[0183] This differs from 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—like the recessed contact surfaces of the housing part 43a—is designed according to Fig. 5a - provided with a sealing material, wherein the inside of the housing cover 43b is additionally fully covered with a sealing material consisting, for example, of cellular rubber.

[0184] This results in a particularly effective sealing of the electronic housing 43 in order to meet the requirements of the higher protection class.

[0185] As mentioned elsewhere, the electronic housings 43 also differ in their respective electronic equipment 45. For example, the electronic housing 43 according to Fig. 5a equipped with a connection for an IEC power connector 44, to which a power supply for the scroll vacuum pump can be connected. In contrast, the electronics housing 43 is designed according to Fig. 5b fitted with a different mains plug 44, for example a mains plug of type Harting.

[0186] Additionally, the electronic housing 43 differs according to Fig. 5b from the electronic housing 43 according to Fig. 5a due to the absence of the Sub-D connector, the standby switch, the on / off switch, and the USB ports. The openings provided for these in housing component 43a are covered, for example, with a film. This allows for the electronic housing 43 according to Fig. 5b an IP protection class can be enabled.

[0187] Fig. 6a Figure 1 shows an overview of various views of a stationary spiral component 11, also referred to as a spiral casing, of a scroll vacuum pump according to the invention. The three upper illustrations in Fig. 6a are enlarged in Fig. 6b shown, whereas the three lower illustrations of the Fig. 6a enlarged in Fig. 6c shown.

[0188] Accordingly, it shows Fig. 7a an overview with various representations of a movable spiral component 13, also referred to as an orbiter, for the spiral casing 11 according to the Fig. 6a , 6band 6c .

[0189] 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, are shown in the Fig. 8a , 8b , 8c and 8d .

[0190] The stationary spiral component 11 comprises a spiral arrangement with spiral walls 49 and a 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 transition into a helical pumping channel formed by a helically extending spiral groove 50 and bounded by a helically extending spiral wall 49.

[0191] The second semicircular spiral wall 49, viewed from the radial outside, has a greater thickness WD2 than the spirally extending spiral wall 49, which has a wall thickness WD1 in its radially inner section. In this embodiment, WD2 = 3.71 mm and WD1 = 3.47 mm. The stability of the circumferentially interrupted circular spiral wall 49 is increased by this greater thickness WD2.

[0192] The spiral walls 49 are each provided at their end furthest from the spiral base 51 with an elongated sealing element 75, also referred to as a tip seal. The sealing element 75 for the outermost radial spiral wall 49 is comparatively long, as it extends to the innermost, 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 housing 11. A special feature of this long sealing element 75 is that, radially outward, it extends to the end 76 of the semicircular spiral wall 49, which reaches a gas inlet 67 (see figure). Fig. 7a and 7b ) of the pump system.

[0193] The gas, pumped along the spiral grooves 50 from radially outside to radially inside, can pass from the spiral grooves 50 through a central inlet opening 55 and through two bypass openings 61a, 63a into a channel system of the stationary spiral component 11, which is 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 circumferentially offset from each other and are located on the same radius with respect to a central axis of the spiral housing 11.

[0194] Aligned with these openings 55, 61a, 63a, openings 56a, 61c, 63c are 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.

[0195] Furthermore, on 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.

[0196] The aforementioned openings communicate with a channel system of the spiral casing 11, which is shown in the illustrations on the left and right. Fig. 6c shown.

[0197] 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.

[0198] Another bypass channel 61 (see the right-hand 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 created to produce the bypass channel 61. This bore 64 and the outlet channel 69 run at an angle to each other, which corresponds to the angular offset of the two bypass openings 61c, 63c in the circumferential direction.

[0199] Another 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 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 spirally extending spiral groove 50 and with a groove width NB2 = 12.92 mm for a radially further outward and circularly extending spiral groove 50, the ratios are 3.93 and 3.87, respectively. A groove depth of 52 mm can alternatively be provided. This results in even larger ratios of groove depth to groove width.

[0200] The movable spiral component 13 according to Fig. 7a and 7bThe assembly also comprises a spiral arrangement with spiral walls 69 and a spiral base 71, as well as a plate-shaped support 73 for the spiral arrangement. The two radially outer spiral walls 69 run on concentric circles and are interrupted circumferentially in the area of ​​a gas inlet 67. A radially inner spiral wall 69 runs in a spiral shape. The spiral walls 69 are each provided with a sealing element 75 (tip seal) at their end facing away from the spiral base 71.

[0201] 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 that is greater than the thickness WD1 of the spiral spiral wall 69. In this embodiment, WD2 = 3.71 mm and WD1 = 3.46 mm.

[0202] As shown on the right in Fig. 7b As can be seen, the radially outer spiral groove 70 between the two semicircular spiral walls 69 has a groove width NB2, while the spirally extending spiral groove 70 bounded by the spiral spiral wall 69 has a groove width NB1. In this 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 alternatively be provided. This would result in even larger ratios of groove depth to groove width.

[0203] Fig. 8a An overview shows various views of the spiral casing. Fig. 6a , 6b and 6c and the orbiter of Fig. 7a and 7b comprehensive pumping system of the scroll vacuum pump according to Fig. 3a and 3b The pumping system of scroll vacuum pumps according to Fig. 1a and 1b as well as Fig. 2a and 2b is appropriately trained.

[0204] Fig. 8b shows an enlarged representation in the upper 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 representation in the lower right (section CC) of Fig. 8a .

[0205] In Fig. 8b The interaction of the interlocking spiral walls 49, 69, which enclose crescent- or sickle-shaped volumes in sections, can be seen. During operation, gas enters via the gas inlet 67, which is located in Fig. 8b only hinted at with regard to his position (see, for example, Fig. 7b ), inflowing gas to the center of the pump 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.

[0206] 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 pump system.

[0207] If overpressure develops in the pump system during operation, it can be relieved by the pressure relief valves 61b, 63b to prevent excessive power consumption by 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, respectively. This ensures that the scroll vacuum pumps according to the invention have a relatively high pumping speed with comparatively low power consumption.

[0208] Fig. 9 shows a concept that is referred to as a conical gap design and can be provided in the scroll vacuum pumps according to the present disclosure in the area where the spirally extending spiral wall 49 of the stationary spiral component interacts with the spirally extending spiral wall 69 of the movable spiral component.

[0209] For each of the three states I, II and III of the scroll vacuum pump, the path of the movable spiral wall 69 in the pumping direction P relative to the stationary spiral walls 49 is shown in a development. In each case, the upper stationary spiral wall 49 is located radially further outwards than the lower stationary spiral wall 49, which is indicated by the arrow r (radial direction).

[0210] The numerical values ​​each represent the radial distance (in mm) between the opposing wall surfaces, i.e., the size of the radial gap between the wall surfaces.

[0211] 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 casing and the orbiter are at ambient temperature.

[0212] 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 profile in the pumping direction P.

[0213] The path of the movable spiral wall 69 is chosen such that, when the scroll vacuum pump is running, i.e., during operation, the deformation of the movable spiral wall 69 reduces the taper of the gaps, as can be seen from the distance values, according to state II. In state II, the movable spiral wall 69 therefore 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.

[0214] At even higher speeds, for example at a drive shaft speed of 1,800 revolutions per minute, according to state III, the centrifugal forces cause the movable spiral wall 69 to approach the radially outer fixed spiral wall 49, resulting in a very small radial gap.

[0215] Fig. 10 shows various external views of a scroll vacuum pump Fig. 3a and 3b .

[0216] 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. The outlet flange 78 and the inlet flange 77 are also shown.

[0217] The special feature of this pump housing 41 is that the inlet flange 77, also referred to as the suction flange, is set back at this axial position relative to the highest point of the pump housing 41. This saves on overall height. This is particularly advantageous when an alternative flange (not shown) is used, which is formed by an angle flange.

[0218] Such a recessed arrangement of the inlet flange 77 is also used in the scroll vacuum pump according to Fig. 2a and 2b planned. Bezugszeichenliste

[0219] 11 Fixed spiral component, spiral housing 13 Moving spiral component, orbiter 15 Axis of rotation 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 Electronic components 47 Cooling projection 49 Spiral wall of the fixed spiral component 50 Spiral groove 51 Spiral base 53 Carrier 55 Inlet opening 56 Outlet valve 56a Opening 57 Outlet 59 Outlet channel 61 Bypass channel 61a Bypass opening 61b Pressure relief valve 61c Opening 62 Plug 63 Bypass channel 63a Bypass opening 63b Pressure relief valve 63c Opening 64 Bore 65 Axial outlet opening 66 Plug 67 Gas inlet of the pump system 69 Spiral wall of the movableSpiral component 70 Spiral groove 71 Spiral base 73 Carrier 75 Sealing element 76 End of spiral wall 77 Inlet flange 78 Outlet flange 79 Gas ballast valve 81 Gas ballast valve cover 82 Rotary knob 83 Central screw 85 Positioning element, positioning pin 87 Pressure element 89 Bellows 91 Flange bearing 93 Pressure washer 94 Shim 95 Fan 97 Positioning pin 99 Wave spring 101 Radial indentation as marker 103 Motor cover 105 Hood 107 Base 109 Manufacturing arrangement NTNot depth NB1Tot width NB2Tot width WD1Thickness of spiral wall WD2Thickness of spiral wall ELevel PPPump direction Radial direction

Claims

1. A scroll vacuum pump comprising - a pumping system (11, 13) which comprises a stationary spiral component (11) and a spiral component (13) cooperating with the former in a pump-active manner, - a drive shaft (17) rotating about an axis of rotation (15) during operation and having an eccentric section (19) for driving the movable spiral component (13), and - an electric drive motor (21, 23) for the drive shaft (17), wherein a balancing weight (31) is placed at the end face onto the rear end of the drive shaft (17), characterized in that the drive motor (21, 23) comprises a radially inner motor rotor (21) and a radially outer motor stator (23), with the motor rotor (21) being clamped between an abutment and the balancing weight (31) which is placed onto the rear end of the drive shaft (17), and wherein the balancing weight (31) serves to clamp the motor rotor (21).

2. A scroll vacuum pump comprising - a pumping system (11, 13) which comprises a stationary spiral component (11) and a spiral component (13) cooperating with the former in a pump-active manner, - a drive shaft (17) rotating about an axis of rotation (15) during operation and having an eccentric section (19) for driving the movable spiral component (13), and - an electric drive motor (21, 23) for the drive shaft (17), wherein a balancing weight (31) is placed at the end face onto the rear end of the drive shaft (17), characterized in that the drive motor (21, 23) comprises a radially inner motor rotor (21) and a radially outer motor stator (23), with the motor rotor (21) being provided with a radially inner sleeve element (33) which is rotationally fixedly connected to the motor rotor (21) and with which the motor rotor (21) is slid onto the drive shaft (17), in particular with a clearance fit, and with the sleeve element (33) being clamped between an abutment and the balancing weight (31) which is placed onto the rear end of the drive shaft (17) as a clamping element.

3. A scroll vacuum pump according to claim 1 or 2, wherein the balancing weight (31) is located behind the drive shaft (17) and is connected to the drive shaft (17) such that the balancing weight (31) rotates together with the drive shaft (17) during operation.

4. A scroll vacuum pump according to any one of the preceding claims, wherein the balancing weight (31) is screwed to the drive shaft (17).

5. A scroll vacuum pump according to claim 4, wherein a central screw (83), whose shank coincides with the axis of rotation (15), is provided for screwing the balancing weight (31) to the drive shaft (17).

6. A scroll vacuum pump according to any one of the preceding claims, wherein the positioning of the balancing weight (31) in the circumferential direction relative to the drive shaft (17) is predefined by a positioning aid (85).

7. A scroll vacuum pump according to claim 6, wherein the positioning aid comprises a positioning element (85) arranged at a radial distance from the axis of rotation (15) and a positioning receiver for a part of the positioning element (85), wherein the positioning element (85) is arranged at the drive shaft (17) and the positioning receiver is formed at the balancing weight (31), or vice versa.

8. A scroll vacuum pump according to claim 7, wherein the positioning element (85) is pin-shaped and extends parallel to the axis of rotation (15).

9. A scroll vacuum pump according to claim 7 or 8, wherein the positioning element (85) can be inserted in the axial direction into a recess during the assembly, in particular wherein the recess is formed in the drive shaft (17) or the recess is formed jointly by the drive shaft (17), on the one hand, and a motor rotor (21) of the drive motor (21, 23) or a radially inner sleeve element (33) which is rotationally fixedly connected to the motor rotor (21) of the drive motor (21, 23), on the other hand.

10. A scroll vacuum pump according to any one of the preceding claims, wherein the drive motor (21, 23) comprises a radially inner motor rotor (21) which is slid onto the drive shaft (17), in particular with a clearance fit, directly or by means of a radially inner sleeve element (33) which is rotationally fixedly connected to the motor rotor (21), wherein a form-fit connection that is effective in the circumferential direction is provided between the motor rotor (21) and the sleeve element (33), on the one hand, and the drive shaft (17), on the other hand.

11. A scroll vacuum pump according to claim 10, wherein the form-fit connection is formed by a positioning element (85) of a positioning aid by means of which the positioning of the balancing weight (31) in the circumferential direction relative to the drive shaft (17) is predefined.

12. A scroll vacuum pump according to any one of the claims 2 to 11, wherein the motor rotor (21) and the sleeve element (33) are press-fitted together.

13. A scroll vacuum pump according to any one of the claims 2 to 12, wherein the sleeve element (33) is formed in one part or in multiple parts.

14. A scroll vacuum pump according to any one of the claims 2 to 13, wherein the drive shaft (17) is provided with a circumferential shoulder (17a) against which the sleeve element (33) rests and which forms the abutment for the sleeve element (33).

15. A scroll vacuum pump according to any one of the preceding claims, wherein at least two bearing points (25, 27) that are spaced apart from one another along the axis of rotation (15) are provided for rotatably supporting the drive shaft (17), and wherein all the bearing points (25, 27) are located on the side of the drive motor (21, 23) that faces the eccentric section (19) and / or between a front balancing weight (29) and a rear balancing weight (31) of the drive shaft (17).