EP3376031A1 - Adjustable wear-resistant rotary pump - Google Patents

Abstract

Rotary pump with adjustable delivery volume, comprising: a) a housing (3, 6), b) a delivery chamber formed in the housing (3, 6) with an inlet (4) for a fluid on a low-pressure side and an outlet (5) for the fluid on a high-pressure side of the pump, c) at least one conveying rotor (2) rotatable in the delivery chamber about a rotation axis (R 2), d) a to an end face of the conveyor rotor (2) arranged or surrounding the conveyor rotor of the actuator (15) which is movable for the adjustment of the delivery volume in the housing (3, 6) back and forth, e) wherein the actuator (15) is acted upon in the direction of its mobility with a dependent on the need for a consumer to be supplied with the fluid actuating force, f) and a raceway (3a) formed in the housing (3, 6), which guides the actuator (15) in sliding contact with an actuator sliding surface (15a), g) wherein a sliding material, the at least one of career (3a) and actuator sliding surface (15a) forms, at least one of plastic, ceramic, nitride, a nickel phosphorus compound or a lubricating paint or by a DLC coating, a Ferroprint Coating or a nano-coating is formed.

Description

The invention relates to a rotary pump with adjustable, preferably adjustable delivery volume and a method for their preparation. The rotary pump can be used in particular as a lubricating oil pump for the lubricating oil supply of an internal combustion engine, in particular a motor vehicle engine.

Automotive fuel oil pumping is driven as a function of the speed of the engine to be supplied with lubricating oil, usually directly or via a mechanical transmission from the engine. The speed of the pump increases accordingly with the speed of the motor. Since rotary pumps have a constant specific delivery volume, ie deliver substantially the same amount of fluid per revolution at each speed, the delivery volume increases proportionally with the pump speed. The demand of the engine increases up to a certain limit speed also approximately proportional to the engine speed, but kinks after reaching the limit speed or at least flattens, so that the rotary pump promotes exceeding the limit speed above demand. In order to manage the excess flow rate lossy in a reservoir, adjustable rotary pumps have been developed. As examples of adjustable rotary pumps are internal and external gear pumps from the DE 102 22 131 B4 known. Furthermore, adjustable vane pumps are known. The pumps each include a reciprocable actuator. In the example cases mentioned, the conveying rotor is either a gear wheel or an impeller. In the known internal gear pumps and vane pumps is adjusted by the movement of the adjusting the eccentricity between two meshing gears or the eccentricity between the impeller and the actuator according to the needs of the consumer. For external gear pumps, the axial engagement length of two gears is adjusted. For adjusting the respective actuator is subjected to a force, for example, directly with the high pressure fluid. The actuating force counteracts a spring member. For pumps of the type mentioned in Increasingly made of light metal alloys, especially Al alloys, are surprisingly subject to the frictional contact surfaces of the pump housing and the actuator a special wear and determine the life of the pump.

It is an object of the invention to extend the life of variable displacement rotary pumps.

The invention is based on a rotary pump of the positive displacement type, which comprises a housing with a delivery chamber, a delivery rotor rotatable in the delivery chamber about a rotation axis, and at least one actuator which can be moved back and forth in the housing. The actuator may surround the conveyor rotor or preferably be arranged to an end face of the conveyor rotor. An actuator surrounding the conveyor rotor can in particular with innenachsigen pumps, such as gerotor pumps and vane pumps, provided as a rotatably mounted eccentric ring as shown in DE 102 22 131 B4 or the EP 0 846 861 B1 be known or formed as a cam ring. However, preferred is an actuator, as known from external gear pumps, for example the DE 102 22 131 B4 , Is arranged to a front side of the conveyor rotor and axially seals the delivery chamber at the respective end face. Such an actuator forms an actuating piston which is axially movable back and forth along the axis of rotation of the feed wheel. An actuator surrounding the conveyor rotor is rotatably or pivotally mounted, but may alternatively be mounted linearly movable. The delivery chamber has a low pressure side and a high pressure side. At least one inlet is located on the low-pressure side and at least one outlet for a fluid to be delivered is arranged on the high-pressure side. The low pressure side of the delivery chamber and the entire upstream part of the system where the pump is installed form the low pressure side of the pump. The high pressure side of the delivery chamber and the entire adjoining downstream part of the system form the high pressure side of the pump. The low pressure side extends to a reservoir for the fluid, and the high pressure side extends to at least the most downstream point of use, which requires high fluid pressure.
The actuator is acted upon in the direction of its mobility with a force that depends on the pressure of the fluid of the high-pressure side of the pump or other relevant for the needs of the size of the system. The pressure can be directly at the outlet of the Delivery chamber or a downstream pump outlet or from a further downstream located in the system, for example, the last point of consumption, be removed. In the formation of the actuating force, instead of the pressure or in addition to the pressure, for example, the temperature of the fluid or a component in the system in which the pump is installed, for example, an engine temperature. Optionally, other or further physical quantities are used to determine the actuating force. The actuating force can be generated by means of an additional actuator, for example an electric motor. More preferably, however, the actuator is directly acted upon by the pressure of the fluid, ie it is acted upon by the pressurized fluid during operation of the pump. The actuator is applied in preferred embodiments, in particular in embodiments in which it is acted upon by the pressure fluid, counteracting the adjusting force with a elasticity force. The elasticity force is generated by a elastic member, preferably by a mechanical spring.

The actuator is in sliding contact with the housing in that the housing forms a raceway and the actuator form an actuator sliding surface and the actuator is guided by means of its sliding surface of the raceway in the sliding contact. The actuator may additionally be performed otherwise, for example in a pivot joint, but more preferably it is only guided by the track.

According to the invention, the actuator sliding surface or the raceway is or are formed from a sliding material. In particular, the sliding material may be a plastic, a ceramic material, a nitride, a nickel-phosphorus compound, a lubricating varnish, a DLC coating, a Ferroprint coating or a nano-coating. The sliding material may form a surface coating. If the sliding material is a plastic, the relevant component, ie, a housing part forming the raceway or the actuator, may consist exclusively or at least substantially of the sliding material. In preferred embodiments, both the actuator sliding surface and the raceway are made of a sliding material, either the same or each of a different sliding material. Wear reductions, however, are already achieved when either only the actuator sliding surface or only the raceway is made of the sliding material, with the preference given to the use of the sliding material for the actuator sliding surface.

The invention is based on the recognition that for the wear furrow, on the other hand, but also adhesion can be decisive. Adhesion may be the wear-determining friction mechanism, in particular, when the frictionally engaged friction partners are so smooth that the friction mechanism of the furrowing or abrasion fades into the background. Thus, it has been found in adjustable external gear pumps that the arranged to the end faces of the axially movable conveyor rotor actuators, namely the two adjusting pistons, subject to a considerable Schwingreibverschleiß. The adjustment movements required for setting the delivery volume can not cause the vibration friction wear. The adjustment movements are too slow. The adjustment movements, however, are superimposed on oscillations with short strokes compared to the control movements and a much higher frequency. Between the sliding surfaces of the actuators and the raceway of the pump housing, therefore, there is an adhesion with the result that local material welds occur, which are broken by the adjustment movements. According to the invention, the sliding partners, i. H. the sliding surface of the actuator or the plurality of actuators and the raceway or multiple raceways of the housing, designed so that the adhesion tendency is significantly reduced in the friction system compared to the usual surfaces for the sliding of aluminum alloys. The sliding material is advantageously chosen so that it has an adhesive energy or free surface energy which is at most half as large as the adhesion energy of pure aluminum. This condition is met in particular by plastic materials and ceramic materials, preferably metal oxide ceramics, but also by the abovementioned further sliding materials. The adhesion energy or free binding energy increases with the density of the free electrons. The requirement for a low adhesion energy therefore meet materials with a low density of free electrons.

A material group which is particularly suitable as a sliding material are temperature-resistant thermoplastics. The polymer or optionally a plurality of polymers of the plastic sliding material are advantageously slip-modified, ie the plastic contains a slip additive which improves the sliding properties. Such a sliding material is also ideally suited in cases where only one of the sliding partners of the friction system consists of sliding material. A preferred slip additive is graphite. Alternatively comes as slip additive above all a polymer from the group of fluoropolymers in question. A preferred example from this group is polytetrafluoroethylene (PTFE). Particularly preferably, both graphite and at least one fluoropolymer, preferably PTFE, are admixed to the polymer, copolymer, the polymer mixture or the polymer blend as a slip additive. The amount of slip additive should be at least 10% by weight in total, more preferably the slip additive is 20% ± 5% in total. If different materials form the slip additive, the individual components should at least be substantially equal. Thus, plastic lubricants containing 10 ± 2 wt% graphite and 10 ± 2 wt% fluoropolymer are preferred. The addition of fiber material is also considered to be advantageous, carbon fibers being preferred as the fiber material. Glass fibers should not be added because they can form fine needle tips on the surface of the sliding layer formed of the sliding material, and therefore deteriorate the sliding properties. The plastic slip material preferably contains 10 ± 5 wt .-%, more preferably 10 ± 3 wt .-% fiber material.

• Polysulfon (PSU) oder insbesondere Polyethersulfon (PES), auch Copolymerisate aus PES und Polysulfon (PSU),
• Polyphenylensulfid (PPS)
• Polyetherketone, nämlich PAEK, PEK oder insbesondere PEEK
• Polyphtalamid (PPA)
• und Polyamid (PA)

Preferred as a sliding material plastics contain 70 ± 10 wt .-% polymer material. Although in principle polymer blends or polymer blends come as a base material in question, the plastic sliding preferably contains only one type of polymer. Polymers with their long hydrocarbon chains have a very low density of free electrons and correspondingly little free space for free electrons of the sliding partner. In this regard, amorphous polymers with their entangled molecular chains are particularly advantageous. The degree of crystallinity of the polymer material should be as low as possible. On the other hand, the polymer material should not have any significant entropy elasticity. The lower service temperature should be at -40 ° C, better below. The continuous service temperature should be at least +150 ° C. Within this service temperature range low creep, sufficient mechanical strength and dimensional stability are required. For use in vehicle construction, the plastic sliding material should also be resistant to fuels. In general, resistance to the pumped fluid is required. It is also advantageous if the sliding material can also embed hard particles, which can result from cleavage, ie abrasion. Preferred polymeric materials are:

• Polysulfone (PSU) or in particular polyethersulfone (PES), also copolymers of PES and polysulfone (PSU),
• Polyphenylene sulfide (PPS)
• Polyether ketones, namely PAEK, PEK or in particular PEEK
• Polyphthalamide (PPA)
• and polyamide (PA)

The actuator is formed in preferred first embodiments of the Kunststoffgleitmaterial, preferably by injection molding. Preferably, in such embodiments, it consists of the plastic. Basically, however, inserts can be embedded in the plastic; In this sense, the actuator consists at least substantially of the plastic sliding material. Instead of the actuator may also be a housing part which forms the raceway, be formed from the Kunststoffgleitmaterial, preferably in the injection molding and solely from the plastic or in the above sense, at least substantially consist of the plastic. In a contrast preferred variant, the housing is formed of a metal, preferably a light metal, and the track is formed by an existing of the Kunststoffgleitmaterial insert part, preferably a bushing. In principle, the actuator and a housing part forming the raceway, in particular insert part, can each be formed from the plastic sliding material. In the context of the first embodiments, it is particularly preferred if only the actuator consists at least substantially of the Kunststoffgleitmaterial, the career, however, is formed by a Kunststoffgleitmaterial or possibly another sliding material only as a surface coating or as an uncoated metal surface.

In preferred second embodiments, at least one of the sliding contact surfaces is formed by a thin sliding layer. The actuator or the housing forming the raceway consists or consist of the superficial sliding layer of a different material, namely a carrier material. The carrier material may in particular be a metal, preferably a light metal. Candidates for light metals are mainly aluminum, aluminum alloys and magnesium alloys. In the second embodiments, both sliding surfaces are preferably formed as superficial sliding layers each comprising a sliding material with a significantly lower adhesion energy than aluminum or magnesium. If only one of the sliding surfaces of the two sliding partners consists of the sliding material, it is preferably the sliding surface of the actuator. Also advantageous is a combination of a first and a second embodiment, in which the actuator or the housing forming the raceway, preferably insert part, at least substantially consists of plastic and the other part has a surface layer of the sliding material, for example also made of plastic or a ceramic material.

The superficial sliding layer can be formed by applying the sliding material or by converting the carrier material. Plastic sliding material is applied, preferably the blank formed from the carrier material is encapsulated with the plastic. The plastic sliding material should have a thermal elongation that comes as close as possible to the elongation of the carrier material. On the other hand, conversion of light-metal carrier materials results in a metal oxide-ceramic sliding layer or a nitride layer. If the support material is aluminum or an aluminum alloy, the sliding layer is preferably obtained by anodization. By anodizing, it is possible in particular to form a so-called Hardcoat® sliding layer (HC layer) or more preferably a so-called Hardcoat® smooth sliding layer (HC-GL layer). Hardcoat® smooth electrolytes consist of a mixture of oxalic acid and additives. For the production of Hardcoat® layers sulfuric acid (H ₂ SO ₄ ) is usually used. Also for magnesium and magnesium alloys as support material anodic oxidation processes are known for providing a metal-ceramic sliding layer comparable with Al ₂ O ₃ sliding layers, for example the so-called DOW method. In the ceramic sliding layer is preferably distributed PTFE, the ceramic is impregnated with PTFE, so to speak.

As already mentioned, the housing or else just one housing part forming the raceway can be shaped in particular from aluminum or an aluminum alloy. The housing or the relevant housing part is preferably cast. The aluminum alloy is therefore preferably an Al casting alloy. If the actuator does not consist at least substantially of plastic sliding material, it is preferably formed from aluminum or an aluminum alloy, preferably a casting alloy, preferably by casting and subsequent extruding or by sintering and calibrating. For both the housing part and the actuator, the particular aluminum alloy preferably contains 10 ± 2% by weight of silicon. Preferably, the respective alloy also contains copper, but with a proportion of at most 4 wt .-%, preferably at most 3 wt .-%. Furthermore, she can do one smaller proportion of iron. The housing part, preferably also other parts of the housing, is or are preferably molded in sand casting or die-casting, with the die cast offering primarily for larger and the sand casting for smaller series. Instead of sand casting, chill casting can also be used. A particularly preferred alloy for the housing part and also for the housing as a whole is AlSi8Cu3, if it is formed by sand casting or chill casting, and AlSi9Cu3 plus a low Fe content, if it is diecast.

Nitrides preferred as the sliding material are titanium carbonitride (TiCN) and in particular nitrided steel. Steels with a high chromium content, preferably with a molybdenum content and also preferably with vanadium, are used as nitrided steels, for example 30CrMoV9. TiCN is used as a surface coating on a light metal carrier material. If nitrided steel forms the sliding material, the corresponding steel is preferably the carrier material. In particular, the actuator may be formed from the steel and the actuator slide surface may be nitrided steel. A particularly preferred sliding pair is hardcoat ceramic or hardcoat smooth ceramic in one and nitrided steel in the other sliding partner. The ceramic sliding material of this pairing may contain PTFE, but low wear is achieved even when using only the ceramic. A glide pairing of hardcoat or hardcoat smooth ceramic with sintered tin bronze is also an alternative, although with regard to thermal expansion, only a limited preferred.

A DLC (Diamond Like Carbon) coating, in particular a tungsten carbide (WC) coating, also reduces wear. A DLC sliding layer can be produced in particular by plasma coating.

Bonded coatings are also suitable sliding materials, which also applies to bonded coatings, that a Verschließminderung Although only one of the sliding partners is achieved in coating, but a bonded coating of both sliding partners of the friction system is given preference. A combination of a lubricating varnish in one and a plastic material in the other sliding partner is also an advantageous solution. The bonded coating consists of an organic or inorganic binder, one or more solid lubricants and Additives. As a solid lubricant in particular MoS ₂ , graphite or PTFE are used individually or in combination. Before coating with the bonded coating, the surface to be coated is pretreated by expediently forming a phosphate layer on the surface to be coated. A special anti-friction varnish is Ferroprint, which contains fine steel flakes as a solid lubricant.

If a nano-coating forms the sliding material, in particular nano-phosphorus compounds can form the sliding layer.

Advantageous features of the invention are also described in the subclaims and their combinations. The features described therein and those described above provide further advantageous feature combinations.

Figur 1

eine Förderkammer einer Außenzahnradpumpe mit zwei in Zahneingriff befindlichen Förderrotoren und

Figur 2

die Außenzahnradpumpe in einem Längsschnitt.

Hereinafter, embodiments of the invention will be explained with reference to figures. The features disclosed in the exemplary embodiments form each individually and in any combination of features which are not mutually exclusive, the objects of the claims and also the embodiments described above. Show it:

FIG. 1

a delivery chamber of an external gear pump with two meshing located conveyor rotors and

FIG. 2

the external gear pump in a longitudinal section.

FIG. 1 shows an external gear pump in a cross section. In a pump housing which has a housing part 3 and a cover 6 (FIG. FIG. 2 ), a delivery chamber is formed in which two externally toothed conveyor rotors 1 and 2 in the form of externally toothed gears rotatably mounted about parallel axes of rotation R ₁ and R ₂ . The conveying rotor 1 is rotationally driven, for example, by the crankshaft of an internal combustion engine of a motor vehicle. The conveyor rotors 1 and 2 are meshed with each other, so that in a rotary drive of the conveyor rotor 1 of the thus meshing conveyor rotor 2 is also rotationally driven. In the delivery chamber open on a low pressure side inlet 4 and on a high pressure side an outlet 5 for a fluid to be conveyed, preferably lubricating oil for an internal combustion engine. The housing part 3 forms the conveyor rotors 1 and 2 facing in the radial direction in each case a radial sealing surface 9, which wraps around the respective conveyor rotor 1 or 2 circumferentially to form a narrow radial sealing gap. For the conveyor rotor 1, the housing 3, 6 further forms on each end side of the conveyor rotor 1 and this axially facing an axial sealing surface, of which in FIG. 1 the sealing surface 7 can be seen. The conveying rotor 2 is axially facing at its two end faces each formed a further axial sealing surface, of which in cross section of FIG. 1 the sealing surface 17 can be seen.

By rotational drive of the conveyor rotors 1 and 2, fluid is sucked through the inlet 4 in the delivery chamber and in the tooth gaps of the conveyor rotors 1 and 2 by the respective wrap on the high pressure side of the delivery chamber and there through the outlet 5 to the consumer, in the example assumed the internal combustion engine , promoted. During the conveying activity, the sealing gaps formed between the conveying rotors 1 and 2 and the said sealing surfaces and the tooth engagement of the conveying rotors 1 and 2 separate the high-pressure side from the low-pressure side. The delivery rate of the pump increases proportionally with the speed of the conveyor rotors 1 and 2. Since an example assumed as a consumer engine from a certain limit speed less lubricating oil absorbs as the pump according to their proportionally with the speed increasing characteristic curve would promote the delivery rate of the pump from the Limiting speed limited. For the shutdown, the conveyor rotor 2 is axially movable relative to the conveyor rotor 1, ie, along its axis of rotation R ₂ , so that the engagement length of the conveyor rotors 1 and 2 and, correspondingly, the delivery rate can be changed.

In FIG. 2 the conveyor rotor 2 assumes an axial position with an axial overlap, ie engagement length, which is already reduced in comparison to the maximum engagement length. The conveyor rotor 2 is part of an adjustment consisting of a bearing pin 14, an actuator 15, an actuator 16 and the rotatably mounted between the actuators 15 and 16 on the bearing pin 14 conveyor rotor 2. The bearing pin 14 connects the actuators 15 and 16 torsionally rigid with each other. The actuator 16 forms the conveying rotor 2 facing the axial sealing surface 17. The actuator 15 forms the other axial sealing surface 18. The entire adjustment is mounted in a sliding chamber of the pump housing 3, 6 axially displaceable back and forth against rotation.

The housing is formed by the housing part 3 and the housing cover 6 firmly connected thereto. The housing cover 6 is formed with a base, whose end surface facing the conveying rotor 1 forms the sealing surface 7. The housing part 3 forms on the opposite end side of the conveyor rotor 1 axially facing the fourth axial sealing surface 8. The sealing surface 8 is provided on its side facing the adjusting unit with a circular segment-shaped cutout for the actuator 15. The actuator 16 is provided on its side facing the conveyor rotor 1 with a circular segment-shaped cutout for the sealing surface 7 forming the base 6. Apart from the respective section, the sealing surface 7 corresponds to the sealing surface 8 and corresponds to the sealing surface 17 of the sealing surface 18th

The adjusting members 15 and 16 of the embodiment are adjusting piston. The sliding chamber, in which the adjusting unit is axially movable back and forth, comprises a limited from the back of the actuator 15 subspace 10 and a limited from the back of the actuator 16 subspace 11. The subspace 11 is connected to the high pressure side of the pump and is constantly pressurized there with branched pressure fluid, which thus acts on the back of the actuator 16. In the space 10, a mechanical compression spring is arranged as the elastic member 12, the elastic force acts on the back of the actuator 16. The elastic member 12 counteracts acting in the subspace 11 on the actuator 16 pressing force. The regulation of such external gear pumps is known and therefore needs no explanation. The regulation may in particular be in accordance with DE 102 22 131 B4 be designed.

If the axial sealing surfaces 7, 8 and 17, 18 circumferentially smooth and the axial sealing gaps accordingly circumferentially tight, would be squeezed in the engagement region of the conveyor rotors 1 and 2 high-pressure fluid, i. still compressed beyond the pressure of the high pressure side and conveyed to the low pressure side. For the squeezing of the fluid drive power is consumed and further connected to the special compression of the fluid and the transport through the meshing through a delivery flow pulsation.

To avoid the disadvantages mentioned, the sealing surfaces 7, 8, 17 and 18 are each provided on the high pressure side with a discharge pocket. Of the four bags are in FIG. 1 the To recognize pockets 7a and 17a. Relief pockets are formed only on the high pressure side.

The housing part 3 guides the actuators 15 and 16 in sliding contact. For the sliding contact, the housing part 3 form a raceway 3a and the housing part 3 together with the cover 6 a raceway 3b, 6b. The actuators 15 and 16 each form an actuator slide surface 15a and 16a on its outer peripheral surface. More specifically, in the sliding contact, the raceway 3a and the actuator sliding surface 15a on the one hand, and the raceway 3b, 6b and the actuator sliding surface 16a on the other hand. In the prior art, it is common to manufacture the housings 3, 6 and the actuators 15 and 16 from light metal alloys. In the friction systems formed from the raceways 3a and 3b, 6b, on the one hand, and the actuator sliding surfaces 15a and 16a, on the other hand, a special sliding material forms at least one of the sliding partners of the respective friction system. Incidentally, in the friction system 3a / 15a, either the raceway 3a or the actuator slide surface 15a may be formed by the sliding material. The same sliding material may further constitute both the raceway 3a and the actuator sliding surface 15a. Finally, the two sliding surfaces 3a and 15a can each be formed by a different sliding material. The same applies with respect to the other friction system 3b, 6b / 16a. If only one of the sliding partners of the respective friction system consists of the sliding material, the same sliding material is expediently used in each case. If both friction partners consist of a sliding material, the actuator sliding surfaces 15a and 16a are each formed by the same sliding material or the raceways 3a, 3b and 6b are each formed by the same sliding material.

Although, in principle, in the respective friction system, one of the sliding partners may consist of a metal alloy, preferably a light metal alloy, it corresponds to preferred exemplary embodiments if each of the sliding partners is formed by a special sliding material of low adhesion energy. The sliding material of the sliding partner of the respective friction system may be the same or different. The actuators 15 and 16 may be formed as a whole from the sliding material or from a carrier material, preferably a light metal alloy, and superficially each have a sliding layer of the sliding material. The housing, in the embodiment, the housing part 3 and the cover 6, may also be formed of plastic, in preferred embodiments, however, at least the housing part 3, preferably also the cover 6, cast from a metal alloy, preferably a light metal alloy. As a light metal in particular aluminum alloys in question. The following are preferred examples:

example 1

Housing part 3 and cover 6: each made of AlSi9Cu3 (Fe) die cast Actuators 15 and 16: PES compound: 10% by weight of carbon fibers, 10% by weight of graphite, 10% by weight of PTFE, remainder PES (eg ULTRASON®)

In Example 1, the housing part 3 and the lid 6 are each die-cast from the same aluminum alloy, namely AlSi9Cu3. The alloy may contain a small amount of Fe. The raceways 3a, 3b and 6b are obtained by mechanical machining accurately. The actuators 15 and 16 are each molded as a whole from the specified plastic sliding material. The sliding surfaces 15a and 16a are accurately produced by mechanical processing.

Example 2

• Housing part 3 and cover 6: each of AlSi9Cu3 (Fe) die-cast
• Actuators 15 and 16: PES compound: 10% by weight carbon fibers, 10% by weight
  Graphite, 10% by weight PTFE, remainder PES (eg ULTRASON®)
• Runways 3a, 3b and 6b: coated with slide-modified plastic or bonded coating

With the exception of the raceways 3a, 3b and 6b, example 2 corresponds to example 1. In contrast to example 1, however, a sliding layer of plastic sliding material or bonded coating respectively forms the raceways 3a, 3b and 6b. The plastic sliding material may in particular be the material of the actuators 15 and 16.

Example 3

Housing part 3 and cover 6: each made of AlSi9Cu3 (Fe) die cast Actuators 15 and 16: Extruded parts of semi-finished aluminum casting as support material, for example AlSi8Cu3 Sliding surfaces 15a and 16a: PES compound: 10% by weight of carbon fibers, 10% by weight of graphite, 10% by weight of PTFE, remainder PES (eg ULTRASON®)

The housing part 3 and the cover 6 correspond to Example 1. The actuators 15 and 16 each consist of the same Al alloy, preferably AlSi8Cu3. They are formed from a cast semi-finished aluminum alloy by extrusion. Subsequently, at least the circumferential surfaces are each provided with a sliding layer of the plastic sliding material. Instead of molding the blanks of the actuators 15 and 16 by extrusion, the blanks can be formed by sintering and calibrating. The extruded or calibrated blanks are heated and overmolded in a mold with the plastic sliding material, preferably completely enveloped.

Example 4

• Housing part 3 and cover 6: each of AlSi9Cu3 (Fe) die-cast
• Runways 3a, 3b and 6b: hardcoat smooth (HC-GL sliding layer, preferably with PTFE impregnation)
• Actuators 15 and 16: Extruded parts of semi-finished aluminum casting as support material, for example AlSi8Cu3
• Sliding surfaces 15a and 16a: hardcoat smooth (HC-GL sliding layer, preferably with PTFE impregnation)

The housing part 3 and the cover 6 correspond to Example 1. The actuators 15 and 16 each consist of the same aluminum alloy, preferably AlSi8Cu3. They are either formed from a cast semi-finished product by extrusion or alternatively by sintering and calibration. Subsequently, the actuator blanks are anodized at least at their respective peripheral surface forming the sliding surface 15a and 16a. The electrolyte used is a mixture of oxalic acid and additives, so that a sliding layer of Al ₂ O ₃ hardcoat smooth forms on the outer peripheral surfaces. Preferably, the sliding layer with PTFE impregnated. The raceways 3a, 3b and 6b are also formed in the same way each as a HC-GL sliding layer, preferably as a PTFE-impregnated sliding layer.

In a modification, one of the two sliding partners or even both sliding partners can each be formed as an HC sliding layer, likewise preferably as a PTFE-impregnated sliding layer.

Example 5

• Housing part 3 and cover 6: each of AlSi9Cu3 (Fe) die-cast
• Runways 3a, 3b and 6b: HC sliding layer
• Actuators 15 and 16: Steel, for example 30CrMoV9, as support material
• Sliding surfaces 15a and 16a: nitrided steel

The housing part 3 and the lid 6 according to Example 1 and are anodized after molding, so that the raceways 3a, 3b and 6b are obtained as Al ₂ O ₃ -Hardcoat (HC sliding layer). The HC overlay may be PTFE impregnated. The actuators 15 and 16 are formed of steel and nitrided on the surface, at least on the outer peripheral surfaces.

Example 6

• Housing part 3 and cover 6: AlSi8Cu3 sand casting or chill casting
• Actuators 15 and 16: Extruded parts of semi-finished aluminum casting as support material, for example AlSi8Cu3
• Sliding surfaces 15a and 16a: hardcoat smooth (HC-Gl sliding layer)

The housing part 3 and the lid 6 are each formed of AlSi8Cu3 in sand casting or chill casting. The raceways 3a, 3b and 6b are produced by mechanical machining accurately. The actuators 15 and 16 are each formed of extruded aluminum semi-finished by extrusion molding and anodized. As the electrolyte, a mixture of oxalic acid and additives is used, so that on the outer peripheral surfaces depending on a sliding layer Al ₂ O ₃ -Hardcoat-Smooth forms (HC-GL sliding layer). The HC-GL overlay preferably contains PTFE.

In a modification, HC-ceramic or HC-smooth ceramic also forms the raceways 3a, 3b and 6b, wherein also there the ceramic can advantageously be impregnated PTFE.

The manufacturing method and choice of material of the last embodiment is particularly suitable for smaller series, while the molding of the housing parts 3 and 6 in die casting for large series is the better choice. Metal-ceramic sliding layers are particularly suitable for use in friction systems with light metal sand casting or - chill cast or generally light metal casting alloys that are solidified in thermodynamic equilibrium or close to the thermodynamic equilibrium. In conjunction with die-cast parts as sliding partners, the smaller α-mixed crystals, for example AlSi, of the die-cast microstructure due to the shorter cooling time, present problems such as fine abrasive grains for metal oxide ceramic sliding layers. If one of the sliding partners has a die-cast structure or generally a metastable phase on its sliding surface, sliding-modified, temperature-resistant thermoplastics are the better choice, or both sliding partners should each have an HC or HC-GL sliding layer. Preferably, however, both sanding or Kokillengussgefügen both sliding from a sliding material low adhesive energy.

• Aspekt 1. Rotationspumpe mit regelbarem Fördervolumen, umfassend
  1. a) ein Gehäuse (3, 6),
  2. b) eine in dem Gehäuse (3, 6) gebildete Förderkammer mit einem Einlass (4) für ein Fluid auf einer Niederdruckseite und einem Auslass (5) für das Fluid auf einer Hochdruckseite der Pumpe,
  3. c) wenigstens einen in der Förderkammer um eine Drehachse (R₂) drehbaren Förderrotor (2),
  4. d) ein zu einer Stirnseite des Förderrotors (2) angeordnetes oder den Förderrotor umgebendes Stellglied (15), das für die Verstellung des Fördervolumens in dem Gehäuse (3, 6) hin und her bewegbar ist,
  5. e) wobei das Stellglied (15) in Richtung seiner Bewegbarkeit mit einer von dem Bedarf eines mit dem Fluid zu versorgenden Verbrauchers abhängigen Stellkraft beaufschlagbar ist,
  6. f) und eine in dem Gehäuse (3, 6) gebildete Laufbahn (3a), die das Stellglied (15) an einer Stellglied-Gleitfläche (15a) in einem Gleitkontakt führt,
  7. g) wobei ein Gleitmaterial, das wenigstens eines aus Laufbahn (3a) und Stellglied-Gleitfläche (15a) bildet, aus wenigstens einem aus Kunststoff, Keramik, Nitrid, einer Nickelphosphorverbindung oder einem Gleitlack besteht oder von einer DLC-Beschichtung, einer Ferroprint-Beschichtung oder einer Nano-Beschichtung gebildet wird.
• Aspekt 2. Rotationspumpe mit regelbarem Fördervolumen, umfassend
  1. a) ein Gehäuse (3, 6),
  2. b) eine in dem Gehäuse (3, 6) gebildete Förderkammer mit einem Einlass (4) für ein Fluid auf einer Niederdruckseite und einem Auslass (5) für das Fluid auf einer Hochdruckseite der Pumpe,
  3. c) wenigstens einen in der Förderkammer um eine Drehachse (R₂) drehbaren Förderrotor (2),
  4. d) ein zu einer Stirnseite des Förderrotors (2) angeordnetes oder den Förderrotor umgebendes Stellglied (15), das für die Verstellung des Fördervolumens in dem Gehäuse (3, 6) hin und her bewegbar ist,
  5. e) wobei das Stellglied (15) in Richtung seiner Bewegbarkeit mit einer von dem Bedarf eines mit dem Fluid zu versorgenden Verbrauchers abhängigen Stellkraft beaufschlagbar ist,
  6. f) und eine in dem Gehäuse (3, 6) gebildete Laufbahn (3a), die das Stellglied (15) an einer Stellglied-Gleitfläche (15a) in einem Gleitkontakt führt,
  7. g) wobei ein Gleitmaterial, das wenigstens eines aus Laufbahn (3a) und Stellglied-Gleitfläche (15a) bildet, eine Adhäsionsenergie aufweist, die höchstens halb so groß wie die Adhäsionsenergie von Aluminium ist.
• Aspekt 3. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei
  • das Stellglied (15), ein weiteres Stellglied (16) und der Förderrotor (2) Bestandteil einer in dem Gehäuse (3, 6) als Gesamtheit hin und her bewegbaren Verstelleinheit (2, 15, 16) sind,
  • die Stellglieder (15, 16) je zu einer der Stirnseiten des Förderrotors (2) angeordnet sind und in dem Gehäuse (3, 6) eine weitere Laufbahn (3b, 6b) gebildet ist, die das weitere Stellglied (16) an dessen Stellglied-Gleitfläche (16a) in einem Gleitkontakt führt,
  • und wobei wenigstens eines aus weiterer Laufbahn (3b, 6b) und Stellglied-Gleitfläche (16a) des weiteren Stellglieds (16) aus dem Gleitmaterial besteht.
• Aspekt 4. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei das Gleitmaterial ein gleitmodifizierter Thermoplast ist.
• Aspekt 5. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei das Gleitmaterial ein Polymer-Compound aus wenigstens einem temperaturfesten, mit Fasermaterial und Gleitzusatz gefüllten Polymer ist.
• Aspekt 6. Rotationspumpe nach dem vorhergehenden Aspekt, wobei der Gleitzusatz wenigstens eines aus Graphit und Fluorpolymer, vorzugsweise PTFE, umfasst.
• Aspekt 7. Rotationspumpe nach einem der zwei vorhergehenden Aspekte, wobei das Fasermaterial Carbonfasern umfasst oder aus Carbonfasern besteht.
• Aspekt 8. Rotationspumpe nach einem der drei vorhergehenden Aspekte, wobei das Gleitmaterial wenigstens eines der folgenden Merkmale erfüllt:
  • der Polymeranteil beträgt wenigstens 60 und höchstens 80 Gew.%,
  • der Anteil des Gleitzusatzes beträgt wenigstens 10 und höchstens 30 Gew.%,
  • der Anteil des Fasermaterials beträgt wenigstens 5 und höchstens 15 Gew.%.
• Aspekt 9. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei das Gleitmaterial ein Kunststoff ist und ein Basismaterial des Kunststoffs ein Polymer einschließlich Copolymer, eine Mischung von Polymeren oder ein Polymerblend aus der Gruppe bestehend aus Polyethersulfon (PES), Polysulfon (PSU) Polyphenylensulfid (PPS), Polyetherketone (PAEK, PEK, PEEK), Polyamide (PA) und Polyphtalamid (PPA) ist.
• Aspekt 10. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei wenigstens eines aus Stellglied-Gleitfläche (15a, 16a) und Laufbahn (3a, 3b, 6b) von einer metallkeramischen Schicht gebildet wird.
• Aspekt 11. Rotationspumpe nach dem vorhergehenden Aspekt, wobei die Schicht eine Hardcoat-Schicht oder Hardcoat-Glatt-Schicht ist und vorzugsweise PTFE enthält.
• Aspekt 12. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei nitrierter Stahl oder TiCN eines aus Laufbahn (3a, 3b, 6b) und Stellglied-Gleitfläche (15a, 16a) bildet.
• Aspekt 13. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei ein die Laufbahn (3a, 3b, 6b) aufweisendes Gehäuseteil (3, 6) zumindest im Wesentlichen aus Metall besteht oder aus einem Metall als Trägermaterial geformt und auf dem Trägermaterial eine die Laufbahn (3a, 3b, 6b) bildende Gleitschicht aus dem Gleitmaterial aufgebracht oder durch Umwandlung des Trägermaterials gebildet ist.
• Aspekt 14. Rotationspumpe nach dem vorhergehenden Aspekt, wobei ein Gussmaterial, vorzugsweise ein Druckgussmaterial, ein Kokillengussmaterial oder ein Sandgussmaterial mit entsprechendem Gefüge, das Gehäuseteil (3, 6) oder das Trägermaterial des Gehäuseteils (3, 6) bildet.
• Aspekt 15. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei das Stellglied (15, 16) einschließlich der Stellglied-Gleitfläche (15a, 16a) zumindest im Wesentlichen aus Metall besteht oder aus einem Metall als Trägermaterial geformt und auf dem Trägermaterial eine die Stellglied-Gleitfläche (15a, 16a) bildende Gleitschicht aus dem Gleitmaterial aufgebracht oder durch Umwandlung des Trägermaterials gebildet ist.
• Aspekt 16. Rotationspumpe nach einer Kombination der Aspekte 13 und 15, wobei das Metall des Gehäuseteils (3, 6) und das Metall des Stellglieds (15, 16) das gleiche metallische Element zumindest als Hauptbestandteil enthalten.
• Aspekt 17. Rotationspumpe nach einem der vier vorhergehenden Aspekte, wobei das Metall ein Leichtmetall, vorzugsweise Aluminium oder eine Al-Basislegierung ist.
• Aspekt 18. Rotationspumpe nach einem der fünf vorhergehenden Aspekte, wobei ein Keramikmaterial des Trägermaterials, vorzugsweise Aluminiumoxid (Al₂O₃), die Gleitschicht bildet.
• Aspekt 19. Rotationspumpe nach einem der sechs vorhergehenden Aspekte, wobei das Metall Aluminium oder eine Al-Basislegierung ist, die Silizium und vorzugsweise wenigstens eines aus Kupfer und Eisen enthält.
• Aspekt 20. Rotationspumpe nach einem der Aspekte 1 bis 14 oder 16 bis 19, wobei das Stellglied (15, 16) aus dem Gleitmaterial geformt ist.
• Aspekt 21. Rotationspumpe nach einem der vorhergehenden Aspekte 1 bis 12 oder 15 bis 20, wobei das Gehäuse (3, 6) oder wenigstens ein die Laufbahn (3a, 3b) bildendes Gehäuseteil (3) aus dem Gleitmaterial geformt ist.
• Aspekt 22. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei der Stellkraft entgegenwirkend ein Elastizitätsglied (12) angeordnet ist.
• Aspekt 23. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei das Stellglied (15, 16) ein Stellkolben ist, der mit dem Fluid der Hochdruckseite beaufschlagbar ist.
• Aspekt 24. Rotationspumpe nach einem der vorhergehenden Aspekte, wobei der Förderrotor (2) und das Stellglied (15, 16) in Bezug auf die Drehachse (R₂) axial bewegbar sind.
• Aspekt 25. Rotationspumpe nach einem der vorhergehenden Aspekte, umfassend einen weiteren Förderrotor (1), der in der Förderkammer um eine weitere Drehachse (R₁) drehbar ist und die Förderrotoren (1, 2) miteinander in einem Fördereingriff sind.
• Aspekt 26. Rotationspumpe nach einem der vorhergehenden Aspekte, die außenachsig und vorzugsweise eine Außenzahnradpumpe ist.
• Aspekt 27. Verfahren zur Herstellung der Rotationspumpe nach einem der vorhergehenden Aspekte, bei dem
  1. a) ein die Laufbahn (3a, 3b, 6b) bildendes Gehäuseteil (3, 6) aus einem Leichtmetall und
  2. b) das Stellglied (15, 16) aus dem gleichen oder einem anderen Leichtmetall geformt werden und
  3. c) das Gehäuseteil (3, 6) zur Erzeugung der Laufbahn (3a, 3b, 6b) oder das Stellglied (15, 16) zur Erzeugung der Stellglied-Gleitfläche (15a, 16a) mit dem Gleitmaterial beschichtet oder
  das Leichtmetall des Gehäuseteils (3, 6) oder das Leichtmetall des Stellglieds (15, 16) an der Oberfläche in das Gleitmaterial umgewandelt wird oder werden.
• Aspekt 28. Verfahren nach dem vorhergehenden Aspekte, bei dem wenigstens eines aus Gehäuseteil (3, 6) und Stellglied (15, 16) im Bereich der Laufbahn (3a, 3b, 6b) oder der Stellglied-Gleitfläche (15a, 16a) keramisiert, vorzugsweise eloxiert, nitriert oder mit einer Kunststoffbeschichtung, einem Gleitlack, einer WC-Beschichtung, einer Ferroprint-Beschichtung oder einer Nano-Beschichtung versehen wird.
• Aspekt 29. Verfahren nach einem der vorhergehenden Aspekte, bei dem das Gehäuseteil (3) aus einer Al-Basislegierung im Sandguss, Kokillenguss oder Druckguss geformt und die Laufbahn (3a, 3b, 6b) vorzugsweise durch mechanische Bearbeitung des Gussmaterials geschaffen wird.
• Aspekt 30. Verfahren nach einem der vorhergehenden Aspekte, bei dem das Stellglied (15, 16) zur Schaffung der Stellglied-Gleitfläche (15a, 16a) mit einem gleitmodifizierten Kunststoff beschichtet wird.

Also in the aspects formulated below, features of the invention will be described. The aspects are formulated in the nature of claims and can replace them. Features disclosed in the aspects may further supplement and / or relativise the claims, show alternatives to individual features, and / or extend claim features. Bracketed numerals refer to the embodiment illustrated in the figures. They do not limit the features described in the aspects in the literal sense as such, but on the other hand show preferred possibilities of realizing the respective feature.

• Aspect 1. Rotary pump with adjustable delivery volume, comprising
  1. a) a housing (3, 6),
  2. b) a delivery chamber formed in the housing (3, 6) with an inlet (4) for a fluid on a low-pressure side and an outlet (5) for the fluid on a high-pressure side of the pump,
  3. c) at least one conveying rotor ( ₂ ) rotatable in the delivery chamber about a rotation axis (R 2),
  4. d) an actuator (15) arranged on an end face of the conveyor rotor (2) or surrounding the conveyor rotor, which actuator is movable back and forth in the housing (3, 6) for the adjustment of the conveyor volume,
  5. e) wherein the actuator (15) is acted upon in the direction of its mobility with a dependent on the need for a consumer to be supplied with the fluid actuating force,
  6. f) and a raceway (3a) formed in the housing (3, 6), which guides the actuator (15) in sliding contact with an actuator sliding surface (15a),
  7. g) wherein a sliding material which forms at least one of raceway (3a) and actuator sliding surface (15a) consists of at least one made of plastic, ceramics, nitride, a nickel phosphorus compound or a lubricating varnish or of a DLC coating, a Ferroprint coating or a nano-coating is formed.
• Aspect 2. Rotary pump with adjustable delivery volume, comprising
  1. a) a housing (3, 6),
  2. b) a delivery chamber formed in the housing (3, 6) with an inlet (4) for a fluid on a low-pressure side and an outlet (5) for the fluid on a high-pressure side of the pump,
  3. c) at least one conveying rotor ( ₂ ) rotatable in the delivery chamber about a rotation axis (R 2),
  4. d) an actuator (15) arranged on an end face of the conveyor rotor (2) or surrounding the conveyor rotor, which actuator is movable back and forth in the housing (3, 6) for the adjustment of the conveyor volume,
  5. e) wherein the actuator (15) is acted upon in the direction of its mobility with a dependent on the need for a consumer to be supplied with the fluid actuating force,
  6. f) and a raceway (3a) formed in the housing (3, 6), which guides the actuator (15) in sliding contact with an actuator sliding surface (15a),
  7. g) wherein a sliding material forming at least one of raceway (3a) and actuator sliding surface (15a) has an adhesion energy of at most half the adhesion energy of aluminum.
• Aspect 3. Rotary pump according to one of the preceding aspects, wherein
  • the actuator (15), another actuator (16) and the conveyor rotor (2) are part of a in the housing (3, 6) as a whole back and forth movable adjusting unit (2, 15, 16),
  • the actuators (15, 16) are each arranged on one of the front sides of the conveyor rotor (2) and in the housing (3, 6) a further track (3b, 6b) is formed which supports the further actuator (16) on its actuator element Sliding surface (16a) leads in a sliding contact,
  • and wherein at least one of further raceway (3b, 6b) and actuator sliding surface (16a) of the further actuator (16) consists of the sliding material.
• Aspect 4. A rotary pump according to any one of the preceding aspects, wherein the sliding material is a slip-modified thermoplastic.
• Aspect 5. A rotary pump according to any one of the preceding aspects, wherein the sliding material is a polymer compound of at least one temperature-resistant polymer filled with fiber material and slip additive.
• Aspect 6. A rotary pump according to the preceding aspect, wherein the slip additive comprises at least one of graphite and fluoropolymer, preferably PTFE.
• Aspect 7. Rotary pump according to one of the two preceding aspects, wherein the fiber material comprises carbon fibers or consists of carbon fibers.
• Aspect 8. A rotary pump according to any one of the preceding three aspects, wherein the sliding material fulfills at least one of the following features:
  • the polymer content is at least 60 and at most 80% by weight,
  • the proportion of slip additive is at least 10 and at most 30% by weight,
  • the proportion of the fiber material is at least 5 and at most 15 wt.%.
• Aspect 9. A rotary pump according to any one of the preceding aspects, wherein the sliding material is a plastic and a base material of the plastic is a polymer including copolymer, a mixture of polymers or a polymer blend selected from the group consisting of polyethersulfone (PES), polysulfone (PSU) polyphenylene sulfide (PPS ), Polyether ketones (PAEK, PEK, PEEK), polyamides (PA) and polyphthalamide (PPA).
• Aspect 10. A rotary pump according to any one of the preceding aspects, wherein at least one of actuator sliding surface (15a, 16a) and raceway (3a, 3b, 6b) is formed of a metal-ceramic layer.
• Aspect 11. A rotary pump according to the preceding aspect, wherein the layer is a hardcoat or hardcoat smooth layer and preferably contains PTFE.
• Aspect 12. A rotary pump according to any preceding aspect, wherein nitrided steel or TiCN forms one of raceway (3a, 3b, 6b) and actuator sliding surface (15a, 16a).
• Aspect 13. Rotary pump according to one of the preceding aspects, wherein the raceway (3a, 3b, 6b) comprising the housing part (3, 6) at least substantially consists of metal or formed of a metal as a carrier material and on the carrier material, a career (3a , 3b, 6b) forming sliding layer of the sliding material is applied or formed by conversion of the carrier material.
• Aspect 14. Rotary pump according to the preceding aspect, wherein a casting material, preferably a die casting material, a chill casting material or a sand casting material with a corresponding structure, the housing part (3, 6) or the carrier material of the housing part (3, 6).
• Aspect 15. A rotary pump according to any one of the preceding aspects, wherein the actuator (15, 16) including the actuator slide surface (15a, 16a) at least substantially consists of metal or formed of a metal as a carrier material and on the carrier material, an actuator sliding surface (15a, 16a) forming sliding layer of the sliding material is applied or formed by conversion of the carrier material.
• Aspect 16. A rotary pump according to a combination of aspects 13 and 15, wherein the metal of the housing part (3, 6) and the metal of the actuator (15, 16) contain the same metallic element at least as a main component.
• Aspect 17. Rotary pump according to one of the four preceding aspects, wherein the metal is a light metal, preferably aluminum or an Al-based alloy.
• Aspect 18. Rotary pump according to one of the five preceding aspects, wherein a ceramic material of the carrier material, preferably aluminum oxide (Al ₂ O ₃ ), forms the sliding layer.
• Aspect 19. A rotary pump according to any one of the six preceding aspects, wherein the metal is aluminum or an Al-based alloy containing silicon and preferably at least one of copper and iron.
• Aspect 20. A rotary pump according to any one of aspects 1 to 14 or 16 to 19, wherein the actuator (15, 16) is formed of the sliding material.
• Aspect 21. A rotary pump according to any preceding aspect 1 to 12 or 15 to 20, wherein the housing (3, 6) or at least one housing part (3) forming the raceway (3a, 3b) is formed of the sliding material.
• Aspect 22. A rotary pump according to any one of the preceding aspects, wherein the adjusting force is disposed counteracting a resilient member (12).
• Aspect 23. A rotary pump according to one of the preceding aspects, wherein the actuator (15, 16) is a control piston, which is acted upon by the fluid of the high pressure side.
• Aspect 24. A rotary pump according to any one of the preceding aspects, wherein the conveyor rotor (2) and the actuator (15, 16) are axially movable with respect to the axis of rotation (R ₂ ).
• Aspect 25. A rotary pump according to one of the preceding aspects, comprising a further conveying rotor (1) which is rotatable in the conveying chamber about a further axis of rotation (R ₁ ) and the conveying rotors (1, 2) are in a conveying engagement with each other.
• Aspect 26. A rotary pump according to any one of the preceding aspects, which is external and preferably an external gear pump.
• Aspect 27. A method of manufacturing the rotary pump according to any one of the preceding aspects, wherein
  1. a) the raceway (3a, 3b, 6b) forming the housing part (3, 6) made of a light metal and
  2. b) the actuator (15, 16) are formed from the same or a different light metal and
  3. c) the housing part (3, 6) for producing the raceway (3a, 3b, 6b) or the actuator (15, 16) for producing the actuator sliding surface (15a, 16a) coated with the sliding material or
  the light metal of the housing part (3, 6) or the light metal of the actuator (15, 16) is or will be converted at the surface into the sliding material.
• Aspect 28. Method according to the preceding aspect, wherein at least one of housing part (3, 6) and actuator (15, 16) in the region of the raceway (3a, 3b, 6b) or the actuator sliding surface (15a, 16a) ceramized, preferably anodized, nitrided or provided with a plastic coating, a bonded coating, a WC coating, a Ferroprint coating or a nano-coating.
• Aspect 29. Method according to one of the preceding aspects, in which the housing part (3) is formed from an Al-based alloy by sand casting, chill casting or die casting and the raceway (3a, 3b, 6b) is preferably created by mechanical working of the casting material.
• Aspect 30. The method of any one of the preceding aspects, wherein the actuator (15, 16) is coated with a slip modified plastic to provide the actuator slide surface (15a, 16a).

Claims (17)

Rotary pump with adjustable delivery volume, comprising a) a housing (3, 6), b) a delivery chamber formed in the housing (3, 6) with an inlet (4) for a fluid on a low-pressure side and an outlet (5) for the fluid on a high-pressure side of the pump, c) at least one conveying rotor ( ₂ ) rotatable in the delivery chamber about a rotation axis (R 2), d) an actuator (15) arranged on an end face of the conveyor rotor (2) or surrounding the conveyor rotor, which actuator is movable back and forth in the housing (3, 6) for the adjustment of the conveyor volume, e) wherein the actuator (15) is acted upon in the direction of its mobility with a dependent on the need for a consumer to be supplied with the fluid actuating force, f) and a raceway (3a) formed in the housing (3, 6), which guides the actuator (15) in sliding contact with an actuator sliding surface (15a), g) wherein a sliding material which forms at least one of raceway (3a) and actuator sliding surface (15a) consists of at least one made of plastic, ceramics, nitride, a nickel phosphorus compound or a lubricating varnish or of a DLC coating, a Ferroprint coating or a nano-coating is formed. A rotary pump according to the preceding claim, wherein - The actuator (15), another actuator (16) and the conveyor rotor (2) are part of a in the housing (3, 6) as a whole back and forth movable adjusting unit (2, 15, 16), - The actuators (15, 16) are each arranged to one of the end sides of the conveyor rotor (2) and in the housing (3, 6), a further track (3b, 6b) is formed, which is the further actuator (16) leads to the actuator sliding surface (16a) in a sliding contact, - And wherein at least one of further career (3b, 6b) and actuator sliding surface (16a) of the further actuator (16) consists of the sliding material. Rotary pump according to one of the preceding claims, wherein the sliding material is a sliding-modified thermoplastic and / or a polymer compound of at least one temperature-resistant, filled with fiber material and slip additive polymer. A rotary pump according to the preceding claim, wherein the sliding additive comprises at least one of graphite and fluoropolymer, preferably PTFE, and / or wherein the fiber material comprises carbon fibers or consists of carbon fibers. Rotary pump according to one of the two preceding claims, wherein the sliding material fulfills at least one of the following features: the polymer content is at least 60 and at most 80% by weight, - the proportion of the slip additive is at least 10 and at most 30% by weight, - The proportion of the fiber material is at least 5 and at most 15 wt.%. A rotary pump according to any one of the preceding claims, wherein the sliding material is a plastic and a base material of the plastic is a polymer including copolymer, a mixture of polymers or a polymer blend selected from the group consisting of polyethersulfone (PES), polysulfone (PSU) polyphenylene sulfide (PPS), polyether ketones (PAEK, PEK, PEEK), polyamides (PA) and polyphtalamide (PPA). Rotary pump according to one of the preceding claims, wherein at least one of the actuator sliding surface (15a, 16a) and the raceway (3a, 3b, 6b) is formed by a metal-ceramic layer, wherein the layer is preferably a hardcoat or hardcoat smooth layer and preferably contains PTFE. A rotary pump according to any one of the preceding claims, wherein nitrided steel or TiCN forms one of raceway (3a, 3b, 6b) and actuator sliding surface (15a, 16a). Rotary pump according to one of the preceding claims, wherein a the raceway (3a, 3b, 6b) comprising the housing part (3, 6) at least substantially consists of metal or formed of a metal as a carrier material and on the carrier material, a career (3a, 3b, 6b) is formed from the sliding material or formed by conversion of the carrier material, wherein a casting material in particular, preferably a die casting material, a chill casting material or a sand casting material with a corresponding structure, the housing part (3, 6) or the carrier material of the housing part (3, 6 ) can form. Rotary pump according to one of the preceding claims, wherein the actuator (15, 16) including the actuator sliding surface (15a, 16a) consists at least substantially of metal or formed of a metal as a carrier material and on the carrier material, the actuator sliding surface (15a, 16a) forming sliding layer is applied from the sliding material or formed by conversion of the carrier material. Rotary pump according to one of the two preceding claims, wherein the metal is a light metal, preferably aluminum or an Al-based alloy. A rotary pump according to any one of claims 1 to 9 or 11, wherein the actuator (15, 16) is formed of the sliding material. Rotary pump according to one of the preceding claims 1 to 8 or 10 to 12, wherein the housing (3, 6) or at least one of the raceway (3a, 3b) forming the housing part (3) is formed from the sliding material. Rotary pump according to one of the preceding claims, wherein the adjusting force counteracting a resilient member (12) is arranged and / or the actuator (15, 16) is an actuating piston which is acted upon by the fluid of the high pressure side. Rotary pump according to one of the preceding claims, wherein the actuator (15, 16) or a raceway forming housing part (3, 6) under a superficial Sliding layer consists of or consists of a carrier material and a plastic sliding material is applied to the carrier material, wherein the blank formed from the carrier material is preferably encapsulated with the plastic sliding material. Method of manufacturing the rotary pump according to one of the preceding claims, in which a) the raceway (3a, 3b, 6b) forming the housing part (3, 6) made of a light metal and b) the actuator (15, 16) are formed from the same or a different light metal and c) the housing part (3, 6) for producing the raceway (3a, 3b, 6b) or the actuator (15, 16) for producing the actuator sliding surface (15a, 16a) coated with the sliding material or the light metal of the housing part (3, 6) or the light metal of the actuator (15, 16) is or will be converted at the surface into the sliding material. Method according to one of the preceding claims, in which the actuator (15, 16) for the creation of the actuator sliding surface (15a, 16a) with a slide-modified Kunststoffbe layers, preferably is encapsulated.

Images