Internal gear pump with pressure pockets on the hollow gear and / or on the housing

Description

[0001] The invention relates to a rotary pump for conveying a fluid, in particular the rotary pump relates to an electrically driven rotary pump as disclosed in the documents JP2013-199850 A or DE10 2007 055 911 A1. The rotary pump is preferably an electric rotary pump for conveying oil to supply a machine unit. In particular, the rotary pump is an oil pump for a motor vehicle for supplying an engine and / or a transmission with oil, in particular lubricating oil. The rotary pump comprises a housing with a conveying chamber, which the housing surrounds and axially delimits at the end faces. The conveying chamber has at least one inlet for the fluid on a low-pressure side of the rotary pump and one outlet for the fluid on the high-pressure side of the rotary pump.

[0002] The pumping chamber of the rotary pump contains a rotatable inner rotor and an outer rotor that rotates around a pump rotation axis and forms pumping cells with the inner rotor. The pump rotation axis of the inner rotor is eccentric to the pump rotation axis of the outer rotor. A circumferential bearing wall, formed by the housing or arranged within the housing, surrounds the outer rotor radially on the outside and supports it in sliding contact for rotation.

[0003] In practice, rotary pumps with a radially mounted outer rotor exhibit start-up problems, especially after extended periods of downtime. These problems arise primarily from friction between the outer peripheral surface of the outer rotor and the inner peripheral surface of the peripheral bearing wall. The adhesive and / or frictional forces between the outer peripheral surface of the inner rotor and the inner peripheral surface of the peripheral bearing wall can be so great that initially no or very little fluid is pumped when the pump starts up. This can lead to damage to the pump and / or to the components that are to be supplied with the fluid pumped by the pump.

[0004] In addition to start-up problems, the fluid in the lubrication gap between the outer peripheral surface of the outer rotor and the inner peripheral surface of the peripheral bearing wall can generate viscous friction, especially at high speeds, which negatively impacts the efficiency of the rotary pump. Since the viscous friction results primarily from the adhesion of the fluid to the stationary inner peripheral surface of the peripheral bearing wall and the moving outer peripheral wall of the outer rotor, and the resulting shearing of the fluid, the viscous friction forces can increase with the pump speed, which can cause the required drive power of the rotary pump to increase disproportionately to the speed.

[0005] Therefore, in conventional rotary pumps with a radially mounted outer rotor, both the outer circumferential surface of the outer rotor and the inner circumferential surface of the peripheral bearing wall are additionally machined to achieve a high surface quality and minimize adhesive and / or frictional forces. Such machining steps require high precision to ensure tolerances are maintained and the lubrication gap between the outer rotor and the peripheral bearing wall does not become excessively large. Such work steps are not only time-consuming but, above all, costly.

[0006] It is therefore an object of the invention to reduce the drive power of the rotary pump and to provide a rotary pump that is cost-effective to manufacture.

[0007] This object is achieved by the rotary pump having the features of claim 1.

[0008] To achieve this object, the invention proposes a rotary pump for conveying a fluid, which comprises a housing with a conveying chamber. The conveying chamber is surrounded by the housing and axially delimited at the end faces and has an inlet for the fluid on a low-pressure side of the rotary pump and an outlet for the fluid on a high-pressure side of the rotary pump. The housing can be constructed in several pieces, in particular in two pieces. The housing preferably comprises at least one housing cover and a housing pot. The housing pot preferably delimits the conveying chamber radially outwardly and on an axial end face, while the housing cover axially delimits the conveying chamber on the end face of the conveying chamber facing away from the housing pot.

[0009] In the delivery chamber of the rotary pump, there is an inner rotor rotatable about a rotational axis, as well as an outer rotor which is rotatable about a pump rotational axis and which forms delivery cells with the inner rotor. The pump rotational axis of the inner rotor is preferably eccentric to the pump rotational axis of the outer rotor, i.e. the pump rotational axis of the inner rotor and the pump rotational axis of the outer rotor are offset. The eccentricity of the pump rotational axis of the outer rotor and the pump rotational axis of the inner rotor can be constant or variable during pump operation. If the eccentricity of the two pump rotational axes is variable, this can be controlled, in particular regulated, depending on the operating state of the rotary pump, for example.

[0010] Preferably, the inner rotor of the rotary pump is driven by a drive means, in particular a drive shaft. The inner rotor can drive the outer rotor. In alternative embodiments, the outer rotor can also be driven by a drive means, in particular a drive shaft. In this case, the outer rotor can drive the inner rotor. Both the inner rotor and the outer rotor can also be driven by a drive means.

[0011] The rotary pump is preferably designed as an electrically driven rotary pump. This means that the drive means, for example a drive shaft, of the inner rotor and / or the outer rotor can be driven by an electric motor. In alternative embodiments, the inner rotor and / or the outer rotor can be driven by the unit to be supplied with fluid, in particular the engine of a motor vehicle.

[0012] The rotary pump is preferably designed as an internal gear pump, with the outer rotor being formed by an internally toothed ring gear and the inner rotor by an externally toothed gear. The inner rotor preferably has at least one tooth fewer than the outer rotor. The outer rotor can, for example, have five teeth and the inner rotor, for example, four teeth. The delivery cells can be formed by the meshing of the teeth of the outer rotor with the teeth of the inner rotor. In particular, the eccentricity of the two pump axes of rotation changes the size of the delivery cells in the circumferential direction of the outer rotor, in particular in the direction of rotation of the outer rotor. Internal gear pumps are well known to those skilled in the art, which is why their structure will not be discussed further here. In alternative embodiments, the rotary pump can, for example, also be designed as a pendulum-vane pump.

[0013] A circumferential bearing wall formed by the housing or arranged in the housing surrounds the outer rotor and rotatably supports it in sliding contact. The outer rotor can be supported by the circumferential bearing wall in radial sliding contact, in particular in circumferential sliding contact. The circumferential bearing wall can be formed by the housing, in particular the housing pot, or by a separate component arranged in the housing, in particular a housing ring. Preferably, the circumferential bearing wall is a part of the housing, in particular the housing pot, and surrounds the outer rotor radially on the outside. The circumferential bearing wall can be joined to an end wall of the housing or can be primary formed, for example, cast or sintered, and together with the end wall form the housing pot.

[0014] The peripheral bearing wall has an inner peripheral surface, which is preferably cylindrical, in particular circular-cylindrical. The outer rotor has an outer peripheral surface, which is preferably cylindrical, in particular circular-cylindrical. The peripheral bearing wall, in particular the inner peripheral surface of the peripheral bearing wall, and the outer rotor, in particular the outer peripheral surface of the outer rotor, are preferably concentric with one another.

[0015] The peripheral bearing wall preferably surrounds the outer rotor with a clearance such that the inner diameter of the peripheral bearing wall is larger than the outer diameter of the outer rotor. The inner diameter of the peripheral bearing wall can be at least 60 µm, in particular at least 70 µm, larger than the outer diameter of the outer rotor. Preferably, the inner diameter of the peripheral bearing wall is a maximum of 110 µm, preferably a maximum of 95 µm, larger than the outer diameter of the outer rotor. The clearance between the outer rotor and the peripheral bearing wall should not be too large to prevent fluid flow through the gap between the outer rotor and the peripheral bearing wall.

[0016] The peripheral bearing wall and / or the outer rotor have a plurality of blind pockets that are radially open towards the outer rotor or the peripheral bearing wall. Preferably, the peripheral bearing wall has a plurality of blind pockets that are radially open towards the outer rotor. In alternative embodiments, the outer rotor can have a plurality of blind pockets that are radially open towards the peripheral bearing wall. The blind pockets interrupt the cylindrical, in particular circular-cylindrical, inner peripheral surface of the peripheral bearing wall and / or the cylindrical, in particular circular-cylindrical, outer peripheral surface of the outer rotor. In this way, the outer rotor and the inner peripheral surface have no contact with one another in the region of the blind pockets. In this way, the effort required to machine the inner peripheral surface of the peripheral bearing wall and / or the effort required to machine the outer peripheral surface of the outer rotor can be reduced, thus saving costs.Furthermore, fluid that inevitably leaks into the gap between the outer rotor and the peripheral bearing wall and is entrained by the rotation of the outer rotor can flow into the blind pockets. This significantly reduces viscous friction.

[0017] The blind pockets are arranged in an asymmetrical distribution over the circumference of the outer rotor and / or over the circumference of the circumferential bearing wall with respect to the circumferential direction, such that at least two adjacent blind pockets over the circumference of the outer rotor and / or over the circumference of the circumferential bearing wall are spaced from one another at a distance in the circumferential direction that is different from the other distances between the blind pockets. In particular, two adjacent blind pockets each delimit an arc length of the outer circumference of the outer rotor in the circumferential direction, wherein the individual arc lengths delimited by the blind pockets can be different or equal. Preferably, at least two adjacent blind pockets delimit an arc length of the outer circumference of the outer rotor in the circumferential direction that is different from the other arc lengths delimited by the blind pockets.

[0018] Preferably, at least one blind pocket, preferably each of the blind pockets, overlaps either only with the inlet or only with the outlet over more than 80% or in particular more than 90% of its circumferential extent. Preferably, at least one of the blind pockets, in particular each of the blind pockets, overlaps either only with the inlet or only with the outlet over its entire circumferential extent.

[0019] In preferred embodiments, the rotary pump comprises at least three or four blind pockets and / or a maximum of five or six blind pockets. Preferably, the rotary pump comprises an even number of blind pockets, in particular four blind pockets. In preferred embodiments, the rotary pump comprises an even number of blind pockets, in particular four blind pockets, wherein a first half of the blind pockets, in particular two of the blind pockets, overlaps only the inlet over more than 80% or more than 90% of their circumferential extent, and a second half of the blind pockets, in particular the other two blind pockets, overlaps only the outlet over more than 80% or more than 90% of their circumferential extent.

[0020] In preferred embodiments, the rotary pump has an even number of blind pockets, in particular four blind pockets, which are arranged mirror-symmetrically with respect to the inner diameter of the peripheral bearing wall and / or the outer diameter of the outer rotor. Preferably, the rotary pump comprises four blind pockets, with two of the blind pockets forming a pair of pockets, and the two pairs of pockets being mirror-symmetrical to one another with respect to the inner diameter of the peripheral bearing wall and / or the outer diameter of the outer rotor.

[0021] In particular, the rotary pump comprises an even number of blind pockets, which can be combined into a first and a second half, wherein the blind pockets of the first half overlap only with the inlet over more than 80% or more than 90% of their circumferential extent, and the blind pockets of the second half overlap only with the outlet over more than 80% or more than 90% of their circumferential extent. The two halves can be mirror-symmetrical to each other with respect to the inner diameter of the circumferential bearing wall and / or the outer diameter of the outer rotor.

[0022] In particular, the rotary pump comprises four blind pockets, which can be combined into two pairs of pockets, wherein the blind pockets of the first pair of pockets overlap only with the inlet over more than 80% or more than 90% of their circumferential extent, and the blind pockets of the second pair of pockets overlap only with the outlet over more than 80% or more than 90% of their circumferential extent. The two pairs of pockets can be mirror-symmetrical to each other with respect to the inner diameter of the peripheral bearing wall and / or the outer diameter of the outer rotor.

[0023] Preferably, one of the blind pockets, in particular each of the blind pockets, extends at least twice as far, preferably at least three times as far, in the circumferential direction of the outer rotor as in the radial direction of the outer rotor. The axial extent of one of the blind pockets, in particular each blind pocket, from a first pocket end to a second pocket end can correspond to at least 70%, preferably at least 80%, of the axial extent of the outer rotor from a first end face of the outer rotor to a second end face of the outer rotor.

[0024] One of the blind pockets, in particular each of the blind pockets, can be formed in the form of a depression, in particular in the form of a recess, in the peripheral bearing wall and / or in the outer rotor, which extends in the axial direction from the second end face of the outer rotor toward the first end face of the outer rotor. The base of the pocket, preferably the base of each blind pocket, can have a radius. The radius of the base of the individual pocket, in particular of each blind pocket, is preferably smaller than the radius of the outer circumference of the outer rotor and / or the inner circumference of the peripheral bearing wall.

[0025] With respect to the circumference of the outer rotor, the blind pockets together have an extent in the circumferential direction of the outer rotor which corresponds to at least 20%, in particular at least 25%, of the circumference of the outer rotor. This means that at least 20% of the outer circumference of the outer rotor, in particular at least 25% of the outer circumference of the outer rotor, is preferably overlapped by the blind pockets. With respect to the circumference of the outer rotor, the blind pockets together have an extent in the circumferential direction of the outer rotor which corresponds to a maximum of 50%, in particular a maximum of 60%, of the circumference of the outer rotor. This means that a maximum of 50% of the outer circumference of the outer rotor, in particular a maximum of 60% of the outer circumference of the outer rotor, is preferably overlapped by the blind pockets.

[0026] In particular, all blind pockets in the circumferential direction of the outer rotor preferably extend over a total of more than 120°, in particular over a total of more than 150°, of the outer circumference of the outer rotor, and / or all blind pockets in the circumferential direction of the outer rotor preferably extend over a maximum of 210°, in particular over a maximum of 180°, of the outer circumference of the outer rotor. Preferably, one of the blind pockets, in particular each of the blind pockets, extends in the circumferential direction over an arc angle that is at least as large as the arc angle of a tooth gap of the outer rotor on the pitch circle of the outer rotor.

[0027] Relative to the diameter of the outer rotor, the blind pockets have a radial extension which preferably corresponds to a maximum of 10% of the outer diameter of the outer rotor, in particular a maximum of 8% of the outer diameter of the outer rotor.

[0028] The blind pockets are preferably fluidically separated from one another in the region of the sliding contact between the outer rotor and the peripheral bearing wall. The blind pockets are preferably fluidically separated from one another in the region of the sliding contact between the outer rotor and the peripheral bearing wall in every rotational position of the outer rotor. In this respect, the sliding contact can also be regarded as a sealed contact. When the application states that the blind pockets are fluidically separated from one another, this means in particular that no fluid flow occurs from one blind pocket to one of the other blind pockets. Natural, in particular unavoidable, leaks due to rotation of the outer rotor are not included. In particular, no fluid is deliberately fed into the sliding contact between the peripheral bearing wall and the outer rotor, for example via a supply line.

[0029] In preferred embodiments, the outer rotor, in sliding contact with the circumferential bearing wall, extends axially beyond at least one of the blind pockets, preferably axially beyond each of the blind pockets, in the direction of the first end face of the outer rotor. This means that the extension of the outer rotor in the axial direction can be greater than the axial extension of one of the blind pockets, in particular can be greater than the axial extension of each pocket. Alternatively or additionally, the circumferential bearing wall, in sliding contact with the outer rotor, can extend axially beyond at least one of the blind pockets, preferably axially beyond each of the blind pockets, in the direction of the first end face of the outer rotor. This means that the extension of the circumferential bearing wall in the axial direction can be greater than the axial extension of one of the blind pockets, in particular can be greater than the axial extension of each pocket.

[0030] If the outer rotor and / or the peripheral bearing wall extend / extends axially beyond at least one of the blind pockets, preferably beyond each of the blind pockets, in sliding contact in the direction of the first end face of the outer rotor, the blind pocket, in particular each blind pocket, ends in a sack-like manner in the region of the outer peripheral surface of the outer rotor in sliding contact or the inner peripheral surface of the peripheral bearing wall in sliding contact. In this way, one blind pocket, in particular each of the blind pockets, can be fluidically separated from the other blind pocket(s), in particular in the region of the first end face of the outer rotor.

[0031] Preferably, the peripheral bearing wall surrounds the outer rotor in sliding contact in the region of the first end face of the outer rotor. In particular, the outer peripheral surface of the outer rotor is in sliding contact with the inner peripheral surface of the peripheral bearing wall in the region of the first end face of the outer rotor over the entire outer circumference of the outer rotor or the entire inner circumference of the peripheral bearing wall.

[0032] Preferably, the sliding contact between the outer circumferential surface of the outer rotor and the inner circumferential surface of the peripheral bearing wall extends over 360° in the region of the first end face of the outer rotor, so that a radial sealing gap is formed between the outer circumferential surface of the outer rotor and the inner circumferential surface of the peripheral bearing wall in the region of the first end face of the outer rotor. The radial sealing gap extends in the axial direction of the outer rotor, preferably over at least 10%, in particular over at least 15%, of the axial dimension of the outer rotor, from its first end face to its second end face.

[0033] The radial sealing gap between the peripheral bearing wall and the outer rotor is preferably interrupted in the region of the first end face of the outer rotor by a maximum of one, in particular none, of the blind pockets. The radial sealing gap preferably serves to prevent fluid communication between the blind pockets in the region of the first end face of the outer rotor.

[0034] Preferably, one blind pocket, preferably each of the blind pockets, terminates axially open on the second end face of the outer rotor on the peripheral bearing wall and / or on the outer rotor. This means that one of the blind pockets, preferably each of the blind pockets, has a second pocket end in the region of the second end face of the outer rotor, which second pocket end is preferably open. The outer rotor and / or the peripheral bearing wall extend / extends in sliding contact toward the second end face of the outer rotor, preferably not axially beyond at least one of the blind pockets, preferably each of the blind pockets.

[0035] The peripheral bearing wall and the outer rotor can fluidically separate the respective blind pocket, preferably each of the blind pockets, from the remaining blind pockets at the open end by sliding contact, particularly by radial sliding contact. The outer peripheral surface of the outer rotor preferably has no contact with the inner peripheral surface of the peripheral bearing wall in the region of the blind pockets, while the outer peripheral surface of the outer rotor and the inner peripheral surface of the peripheral bearing wall have sliding contact, preferably sealing contact, in the region between the blind pockets.

[0036] The housing preferably comprises a housing cover which axially delimits the conveying chamber on the second end face of the outer rotor and bears against the circumferential bearing wall with an axial sealing contact. In particular, the housing cover can form an axial sealing gap with the circumferential bearing wall. The axial sealing contact between the housing cover and the circumferential bearing wall is preferably formed in the circumferential direction of the circumferential bearing wall over the entire circumference of the circumferential bearing wall. The axial sealing contact between the circumferential bearing wall and the housing cover, in particular between the end face of the circumferential bearing wall formed in the region of the second end face of the outer rotor and the end face of the housing cover facing the circumferential bearing wall, preferably extends in the region of the second end face of the outer rotor over 360° of the outer circumference of the circumferential bearing wall.In this way, the blind pockets can be fluidically separated from one another in the region of the second end face of the outer rotor. If the blind pockets have an open end in the region of the second end face of the outer rotor, the blind pockets are preferably fluidically separated from one another in the region of the second pocket end by the axial sealing contact, in particular by the axial sealing gap.

[0037] The housing cover can abut against the outer rotor with an axially sealing sliding contact. Particularly preferably, the second end face of the outer rotor and the housing cover, in particular an end face of the housing cover facing the outer rotor, have an axial sealing gap. The housing cover preferably abuts against the outer rotor with an axial sliding contact, in particular with an axial sealing contact. The axial sealing gap between the housing cover and the peripheral bearing wall can be smaller than the axial sealing gap between the housing cover and the outer rotor.

[0038] The axial sealing gap between the housing cover and the outer rotor is preferably formed over the entire circumference of the outer rotor in the circumferential direction of the outer rotor. The axial sealing gap preferably extends between the second end face of the outer rotor and the housing cover, in particular between the second end face of the outer rotor and the end face of the housing cover facing the outer rotor, in the region of the second end face of the outer rotor over 360° of the outer circumference of the outer rotor. In this way, the blind pockets can be fluidically separated from one another in the region of the second end face of the outer rotor. If the blind pockets have an open end in the region of the second end face of the outer rotor, the blind pockets are preferably fluidically separated from one another in the region of the second pocket end by the axial sealing gap.

[0039] The outer rotor can have an edge break on its first end face along its circumferential outer edge. An edge break preferably involves the removal of edge material, i.e. the circumferential outer edge of the outer rotor is preferably not sharp-edged on the first end face. The edge break can be rounded, i.e. have a radius. The edge break is preferably formed over the entire length of the circumferential outer edge. The edge break preferably measures at least 200 µm or at least 300 µm in the radial direction and / or a maximum of 400 µm or a maximum of 500 µm. The edge break preferably measures at least 200 µm or at least 300 µm in the axial direction and / or a maximum of 400 µm or a maximum of 500 µm.

[0040] The edge break, in particular the rotor chamfer, can be created during the manufacture of the outer rotor, especially during the primary forming of the outer rotor. The outer rotor is preferably manufactured using a primary forming process, for example, by sintering or casting. In alternative embodiments, the edge break, in particular the rotor chamfer, can be subsequently formed by deburring the outer peripheral edge, for example, by brushing, grinding, or filing.

[0041] Particularly preferably, the outer rotor has a rotor chamfer on its first end face along its outer peripheral edge. A chamfer, as defined in the application, is preferably understood to be an edge break in the form of a beveled, in particular flat, surface dimensionally defined in width and angle. The beveled surface is preferably curved exclusively in the circumferential direction of the outer rotor.

[0042] The beveled surface, in particular the rotor chamfer, can preferably be formed at an angle of 45° to the axial direction of the outer rotor. In alternative embodiments, the beveled surface, in particular the rotor chamfer, can also be formed at an angle of 60° to the axial direction of the outer rotor. The rotor chamfer can be formed at any other angle greater than 0° and less than 90° to the axial direction of the outer rotor. The rotor chamfer preferably measures at least 200 µm or at least 300 µm and / or a maximum of 400 µm or a maximum of 500 µm in the radial direction. The rotor chamfer preferably measures at least 200 µm or at least 300 µm and / or a maximum of 400 µm or a maximum of 500 µm in the axial direction. In particular, the rotor chamfer measures at least 300 µm in the radial and axial directions at an angle of 45° to the axial direction of the outer rotor.

[0043] The circumferential bearing wall can have an inner edge transition on the first end face of the outer rotor, i.e. on the axial side of the first end face of the outer rotor, along its circumferential inner edge. An inner edge transition is preferably an overhang of material, i.e. the circumferential inner edge of the circumferential bearing wall is preferably not sharp-edged on the first end face of the outer rotor. The inner edge transition can be rounded, i.e. have a radius. Preferably, the inner edge transition is formed over the entire length of the circumferential inner edge. In particular, in the event that the circumferential bearing wall is formed integrally with an end wall of the housing, the inner edge transition is formed along the inner edge between the end wall and the circumferential bearing wall.

[0044] Particularly preferably, the peripheral bearing wall on the first end face of the outer rotor has an inner edge ridge along its circumferential inner edge. An inner edge ridge within the meaning of the application is preferably understood to mean an inner edge transition in the form of a beveled, in particular flat, surface dimensionally defined in width and angle. The beveled surface is preferably curved exclusively in the circumferential direction of the peripheral bearing wall.

[0045] The inner edge transition, in particular the inner edge burr, can be produced during the manufacture of the peripheral bearing wall, in particular during the primary forming of the peripheral bearing wall. The peripheral bearing wall is preferably produced as part of the housing pot in a primary forming process, for example, by sintering or casting. The inner edge transition, in particular the inner edge burr, is preferably formed in a subsequent manufacturing step during the post-processing of the inner peripheral surface of the peripheral bearing wall, for example, by milling, grinding, or honing.

[0046] The beveled surface, in particular the inner edge burr, can preferably be formed at an angle of 45° to the axial direction of the outer rotor or the peripheral bearing wall. In alternative embodiments, the beveled surface, in particular the inner edge burr, can also be formed at an angle of 60° to the axial direction of the outer rotor or the peripheral bearing wall. The inner edge burr can be formed at any other angle greater than 0° and less than 90° to the axial direction of the outer rotor or the peripheral bearing wall. The inner edge burr preferably measures at least 200 µm or at least 300 µm and / or a maximum of 400 µm or 500 µm in the radial direction. The inner edge burr preferably measures at least 200 µm or at least 300 µm and / or a maximum of 400 µm or 500 µm in the axial direction. In particular, the inner edge burr measures at least 300 µm in the radial and axial directions at an angle of 45° to the axial direction of the outer rotor.

[0047] In particularly preferred embodiments, the outer rotor has a broken edge and the peripheral bearing wall has an inner edge transition, and the broken edge of the outer rotor overlaps with the inner edge transition of the peripheral bearing wall. This means that the inner edge transition is particularly preferably designed to correspond to the broken edge. The inner edge transition forms, so to speak, an imprint or negative of the broken edge. The inner edge transition preferably has the same radius or angle as the broken edge. If the inner edge transition is an inner edge burr, the broken edge is preferably designed in the form of a rotor chamfer, wherein the angle to the axial direction of the outer rotor and the extension in the axial direction of the inner edge burr are equal to the angle to the axial direction of the outer rotor and the extension in the axial direction of the rotor chamfer.

[0048] Particularly preferably, the edge break is a rotor chamfer which measures at least 300 µm in the radial direction and at least 300 µm in the axial direction at an angle of 45° to the axial direction of the outer rotor, and the inner edge transition is an inner edge burr which measures at least 300 µm in the radial direction and at least 300 µm in the axial direction at an angle of 45° to the axial direction of the outer rotor.

[0049] In preferred embodiments, the peripheral bearing wall on the second end face of the outer rotor has no edge break along its circumferential inner edge and / or the outer rotor has only a small second edge break along its circumferential outer edge. In cases where the peripheral bearing wall on the second end face of the outer rotor has no edge break along its circumferential inner edge and / or the outer rotor has no edge break on its second end face along its circumferential outer edge, the edge along the circumferential inner edge of the peripheral bearing wall and / or along the circumferential outer edge of the outer rotor is sharp-edged.

[0050] In cases where the circumferential bearing wall on the second end face of the outer rotor has no edge break or only a small second edge break along its circumferential inner edge and / or the outer rotor has no edge break or only a small second edge break on its second end face along its circumferential outer edge, at least one of the blind pockets, preferably each of the blind pockets, can terminate axially open on the circumferential bearing wall and / or on the outer rotor on the second end face of the outer rotor. In this case, the lack of edge break or the small second edge break along the circumferential inner edge of the circumferential bearing wall and / or along the circumferential outer edge of the outer rotor ensures that the blind pockets in the region of the second end face of the outer rotor have no fluidic connection, in particular in the form of a fluid flow, along the circumferential inner edge of the circumferential bearing wall and / or along the circumferential outer edge of the outer rotor.The small second edge break, if present, along the circumferential inner edge of the circumferential bearing wall and / or along the circumferential outer edge of the outer rotor is preferably so small that no fluid flow can form between the individual blind pockets.

[0051] A very small second edge break is understood in particular to mean deburring along the inner circumferential edge of the circumferential bearing wall and / or along the outer circumferential edge of the outer rotor, in particular deburring by brushing, filing or grinding. This means that when a small second edge break is mentioned, it is the result of a deburring measure, but not a bevel dimensionally defined in width and angle. This means that the small second edge break, if present, is not a chamfer with a bevel dimensionally defined in width and angle. Preferably, the small second edge break has a maximum extension of 100 µm in the axial direction. In particular, the small second edge break has a maximum extension of 100 µm in the radial direction.

[0052] The outer rotor can have an edge break, in particular a rotor chamfer, on its first end face along its peripheral outer edge, and a small second edge break on its second end face along its peripheral outer edge, wherein the edge break, in particular the rotor chamfer, is at least three times as large, in particular four times as large, in the axial direction as the second edge break.

[0053] The circumferential bearing wall can have an inner edge transition, in particular an inner edge ridge, on the first end face of the outer rotor along its circumferential inner edge, and a small edge break on the second end face of the outer rotor along its circumferential inner edge, wherein the inner edge transition, in particular the inner edge ridge, is at least three times as large, in particular four times as large, in the radial direction as the edge break of the outer circumferential edge of the outer rotor on its first end face.

[0054] The invention is explained below using an exemplary embodiment. Features disclosed in the exemplary embodiment advantageously develop the subject matter of the claims and the embodiments explained above, but do not limit the invention. The figures show: Figure 1: a top view of the delivery chamber of the rotary pump, Figure 2: a section in the axial direction of the rotary pump with delivery element, Figure 3: a detailed view of the section from Figure 2 , Figure 4: an axial section through the outer rotor, Figure 5: a detailed view of the axial section from Figure 4 , Figure 6: a plan view of the delivery chamber of the rotary pump without delivery element, Figure 7: an axial section through the rotary pump without delivery element and Figure 8: a detailed view of the axial section from Figure 7 .

[0055] All figures show a rotary pump and its components of an exemplary embodiment. The invention is not limited to the exemplary embodiment and can be designed in accordance with the preceding explanations.

[0056] Figure 1 shows a top view of the discharge chamber of the rotary pump, while Figure 2 a section through the rotary pump after Figure 1 in the axial direction of the rotary pump. Figure 3 shows a detailed view of the Figure 2 . The Figures 6-8 show the rotary pump of the Figure 1 , only without the funding element 3, 4.

[0057] The rotary pump comprises a housing 1 with a delivery chamber 5, which surrounds the housing 1 and is axially delimited at the end faces. As shown in particular in the Figures 2 and 7As can be seen, the housing 1 comprises a housing pot 11 and a housing cover 12. The housing cover 12 delimits the delivery chamber in the axial direction, while the housing pot 11 surrounds the delivery chamber in the radial direction and axially delimits it on the side facing away from the housing cover 12. The delivery chamber 5 has an inlet 6 for a fluid on a low-pressure side of the rotary pump and an outlet 7 for the fluid on the high-pressure side of the pump.

[0058] A conveying element is formed in the conveying chamber 5, which conveys the fluid from the low-pressure side of the rotary pump, in particular from the inlet 6, to the high-pressure side of the rotary pump, in particular the outlet 7. The rotary pump is designed as an internal gear pump or gerotor pump. The conveying element comprises an outer rotor 3 and an inner rotor 4, wherein the outer rotor 3 is formed by an internally toothed ring gear and the inner rotor 4 by an externally toothed gear, and the teeth of the inner rotor 4 can engage with the teeth of the outer rotor 3 through the rotation of the two rotors. The inner rotor 4 preferably has one fewer tooth than the outer rotor 3. In the exemplary embodiment, the outer rotor 3 has five teeth and the inner rotor 4 has four teeth, wherein the number of individual teeth is only exemplary and can vary.

[0059] Through the engagement of the inner rotor 4 with the outer rotor 3, the two rotors form conveying cells, which can change their volume in the circumferential direction of the outer rotor 3 with the rotation of the two rotors. In the present embodiment, the inner rotor 4, as shown in Figure 2 is disclosed, driven by a drive means, in particular a drive shaft. The inner rotor 4 is rotatably mounted about the pump rotation axis R 4 and drives the outer rotor 3, in particular through the engagement of the individual teeth with one another. Preferably, the inner rotor 4 is driven by an electric motor. In alternative embodiments, the inner rotor 4 can also be driven, for example, by the unit to be supplied. Furthermore, in alternative embodiments, the outer rotor 3 can also be driven by a drive means, wherein the inner rotor 4 is driven via the outer rotor 3.

[0060] The pump rotation axis R 4 of the inner rotor 4 is eccentric to the pump rotation axis R 3 of the outer rotor 3, i.e., the pump rotation axis R 4 of the inner rotor 4 and the pump rotation axis R 3 of the outer rotor 3 are offset. The eccentricity of the pump rotation axis R 3 of the outer rotor 3 and the pump rotation axis R 4 of the inner rotor 4 is constant in the present embodiment, but can also be variable in alternative designs. With a variable eccentricity of the two pump rotation axes, this can be changed, in particular controlled, for example, depending on the operating state of the rotary pump.

[0061] The housing pot 11 forms a peripheral bearing wall 2, which surrounds the outer rotor 3 and supports it in a sliding contact so that it can rotate around the pump rotation axis R 3. In alternative embodiments, the peripheral bearing wall 2 can also be formed, for example, by a separate ring inserted into the pumping chamber 5. As shown, for example, in Figure 2 As shown, the peripheral bearing wall 2 is formed integrally with the housing pot 11, in particular an end wall of the housing pot 11, in particular in a primary forming process.

[0062] As in Figure 1As can be seen, the circumferential bearing wall 2 has a plurality of blind pockets 21, 22, 23, 24 which are radially open towards the outer rotor 3 and which are fluidically separated from one another in the region of the sliding contact between the outer rotor 3 and the circumferential bearing wall 2. According to the exemplary embodiment, the rotary pump comprises four blind pockets 21, 22, 23, 24 which are formed in the circumferential bearing wall 2. In alternative embodiments, the number of blind pockets can vary and should not be limited to four blind pockets. The blind pockets are fluidically separated from one another in every rotational position of the outer rotor 3. This means that regardless of the rotational angular position of the outer rotor 3, the blind pockets 21, 22, 23, 24 are fluidically separated from one another in the region of the radial sliding contact between the outer rotor 3 and the circumferential bearing wall 2.

[0063] In alternative embodiments, the blind pockets 21, 22, 23, 24 are formed in the outer rotor 3 and are radially open in the direction of the peripheral bearing wall 2. Even if the blind pockets 21, 22, 23, 24 are formed in the outer rotor 3, the blind pockets 21, 22, 23, 24 are fluidically separated from one another in the region of the radial sliding contact between the outer rotor 3 and the peripheral bearing wall 2, regardless of the rotational angular position of the outer rotor 3.

[0064] The peripheral bearing wall 2 surrounds the outer rotor 3 in the region of a first end face 31 of the outer rotor 3 in radial sliding contact. In particular, the outer peripheral surface of the outer rotor 3 is in sliding contact with the inner peripheral surface of the peripheral bearing wall 2 in the region of the first end face 31 of the outer rotor 3 over the entire outer circumference of the outer rotor 3 or the entire inner circumference of the peripheral bearing wall 2 to form a radial sealing gap. The radial sealing gap extends in the axial direction of the outer rotor 3 over at least 10%, in particular over at least 15%, of the axial dimension of the outer rotor 3 from its first end face 31 to its second end face 32.

[0065] As in Figure 1 and Figure 6As can be seen, the blind pockets 21, 22, 23, 24 are arranged in an asymmetrical distribution around the circumference of the outer rotor 3 with respect to the circumferential direction. In particular, the blind pockets 22 and 23 are spaced apart from one another around the circumference of the outer rotor 3 with respect to the circumferential direction, which is greater than the other distances between the individual blind pockets. For example, the distance between the blind pocket 23 and the blind pocket 24 is smaller than the distance between the blind pockets 22 and 23.

[0066] As can be seen in particular from the Figure 6As can be seen, the blind pockets 23 and 24 can overlap only with the outlet 7 over more than 90% of their circumferential extension in the circumferential direction of the outer rotor 3 or in the circumferential direction of the circumferential bearing wall 2. In particular, the blind pockets 23 and 24 completely overlap with the outlet 7 in the circumferential direction of the circumferential bearing wall 2. Furthermore, the blind pockets 21 and 22 can overlap only with the inlet 6 over more than 90% of their circumferential extension in the circumferential direction of the outer rotor 3 or in the circumferential direction of the circumferential bearing wall 2. In particular, the blind pockets 21 and 22 completely overlap with the inlet 6 in the circumferential direction of the circumferential bearing wall 2.

[0067] As in the Figures 2 and 6As disclosed, the rotary pump has four blind pockets 21, 22, 23, 24, which are arranged mirror-symmetrically with respect to the inner diameter d of the peripheral bearing wall 2 and / or the outer diameter D of the outer rotor 3. The blind pockets 21 and 22 form a first pair of pockets, and the blind pockets 23 and 24 form a second pair of pockets, wherein the two pairs of pockets are mirror-symmetrical to one another with respect to the inner diameter d of the peripheral bearing wall 2 and / or the outer diameter D of the outer rotor 3. The axis of symmetry or the inner diameter d of the peripheral bearing wall 2 and / or the outer diameter D of the outer rotor 3 are Figure 6indicated by a dashed double arrow. The blind pockets 21, 22 of the first pair of pockets overlap only with the inlet 6 by more than 80% or more than 90% of their circumferential extent, and the blind pockets 23, 24 of the second pair of pockets overlap only with the outlet 7 by more than 80% or more than 90% of their circumferential extent.

[0068] Preferably, the blind pockets 21, 22, 23, 24 extend in the circumferential direction of the outer rotor 3 at least twice as far, preferably at least three times as far, as in the radial direction of the outer rotor 3. As can be seen in particular from the Figures 3 and 8 As can be seen from the example of the blind pocket 24, the axial extension of the blind pockets 21, 22, 23, 24 from a first pocket end 24a to a second pocket end 24b can correspond to at least 70%, preferably at least 80%, of the axial extension of the outer rotor 3 from a first end face 31 to a second end face 32.

[0069] With respect to the circumference of the outer rotor 3, the blind pockets 21, 22, 23, 24 together have an extension in the circumferential direction of the outer rotor 3 which corresponds to at least 20%, in particular at least 25%, of the circumference of the outer rotor 3. This means that preferably at least 20% of the outer circumference of the outer rotor 3, in particular at least 25% of the outer circumference of the outer rotor 3, are overlapped by the blind pockets 21, 22, 23, 24.

[0070] Relative to the outer diameter D of the outer rotor 3, the blind pockets 21, 22, 23, 24 have a radial extension which preferably corresponds to a maximum of 10% of the outer diameter D of the outer rotor 3, in particular a maximum of 8% of the outer diameter D of the outer rotor 3.

[0071] As can be seen in particular from the Figures 3 and 8As can be seen from the blind pocket 24, the outer rotor 3 extends axially beyond the blind pocket 24 in sliding contact in the direction of its first end face 31. Preferably, the outer rotor 3 extends axially beyond each of the blind pockets 21, 22, 23, 24 in sliding contact in the direction of its first end face 31. According to the exemplary embodiment, the outer rotor 3 extends further in the axial direction than the blind pockets 21, 22, 23, 24.

[0072] The peripheral bearing wall 2 also extends in sliding contact in the direction of the first end face 31 of the outer rotor 3 axially beyond the blind pocket 24. Preferably, the peripheral bearing wall 2 extends in sliding contact in the direction of the first end face 31 of the outer rotor 3 axially beyond each of the blind pockets 21, 22, 23, 24. As shown in particular in Figure 3As can be seen, the peripheral bearing wall 2 and the outer rotor 3 have the same axial extent. The blind pocket 24, however, has an axial extent that is smaller than the axial extent of the peripheral bearing wall 2 and the outer rotor 3.

[0073] Because the outer rotor 3 and the peripheral bearing wall 2 extend axially beyond the blind pockets 21, 22, 23, 24 in sliding contact toward a first end face 31 of the outer rotor 3, the blind pockets 21, 22, 23, 24 end in a sack-like manner in the region of the outer peripheral surface of the outer rotor 3 in sliding contact and the inner peripheral surface of the peripheral bearing wall 2 in sliding contact. Furthermore, the outer rotor 3 and the peripheral bearing wall 2 form a radial sealing gap in the region of the first end face 31 of the outer rotor 3. The radial sealing gap is not penetrated by any of the blind pockets 21, 22, 23, 24. In this way, the blind pockets 21, 22, 23, 24 are fluidically separated from one another in the region of the first end face 31 of the outer rotor 3.

[0074] In the region of the second end face 32 of the outer rotor 3, the blind pocket 24, preferably each of the blind pockets 21, 22, 23, 24, extends axially open on the peripheral bearing wall 2. This means that the blind pocket 24, preferably each of the blind pockets 21, 22, 23, 24, has a second pocket end 24b in the region of the second end face 32 of the outer rotor 3, which is open.

[0075] The outer rotor 3 and the peripheral bearing wall 2 extend in sliding contact toward the second end face 32 of the outer rotor 3, not extending axially beyond the blind pocket 24, preferably each of the blind pockets 21, 22, 23, 24. The peripheral bearing wall 2 and the outer rotor 3 fluidically separate the blind pockets 21, 22, 23, 24 at the open end 24b in sliding contact between the individual blind pockets 21, 22, 23, 24.

[0076] Furthermore, the housing cover 12, which axially delimits the delivery chamber 5 at the second end face 32 of the outer rotor 3, bears against the peripheral bearing wall 2 with an axial sealing contact and forms an axial sealing gap with the peripheral bearing wall 2. The housing cover 12 bears against the outer rotor 3 in an axial sliding contact. In particular, the second end face 32 of the outer rotor 3 and the housing cover 12 have an axial sealing gap. The housing cover 12 bears against the outer rotor 3 in an axial sliding contact, in particular an axial sealing contact. The axial sealing gap between the housing cover 12 and the peripheral bearing wall 2 is smaller than the axial sealing gap between the housing cover 12 and the outer rotor 3.

[0077] The axial sealing gap between the housing cover 12 and the peripheral bearing wall 2 is formed in the circumferential direction of the outer rotor 3 over the entire circumference of the peripheral bearing wall 2. In this way, the blind pockets 21, 22, 23, 24 in the region of the second end face 32 of the outer rotor 3 are fluidically separated from one another by the peripheral bearing wall 2 and the housing cover 12.

[0078] The axial sealing gap between the housing cover 12 and the outer rotor 3 is formed in the circumferential direction of the outer rotor 3 over the entire circumference of the outer rotor 3. The axial sealing gap extends between the second end face 32 of the outer rotor 3 and the housing cover 12. In this way, the blind pockets 21, 22, 23, 24 are fluidically separated from one another in the region of the second end face 32 of the outer rotor 3. In particular, since the blind pockets 21, 22, 23, 24 have an open-ended pocket end 24b in the region of the second end face 32 of the outer rotor 3, the blind pockets 21, 22, 23, 24 are fluidically separated from one another in the region of the second pocket end 24b by the axial sealing gap. In particular, the blind pockets 21, 22, 23, 24 are fluidically separated from one another by the axial sealing gap between the housing cover 12 and the peripheral bearing wall 2 and the axial sealing gap between the housing cover 12 and the outer rotor 3 in the region of the second end face 32 of the outer rotor 3.

[0079] As in particular the Figures 4 and 5 show, the outer rotor 3 has an edge break 31a on its first end face 31 along its outer peripheral edge. As can be seen in particular from the Figure 5 As can be seen, the edge break 31a according to the present embodiment is designed in the form of a rotor chamfer. The rotor chamfer preferably has an angle of 45° and extends at least 300 µm in the radial and axial directions. In alternative embodiments, the rotor chamfer can also have a different angle, for example, an angle of 60°. In particular, the outer rotor 3 has no sharp-edged transition between the first end face 31 and the circumferential outer surface on its first end face 31 along its outer circumferential edge.

[0080] As particularly in Figure 8As disclosed, the circumferential bearing wall 2 has an inner edge transition 2a on the first end face 32 of the outer rotor 3, i.e. on the axial side of the first end face 31 of the outer rotor 3, along its circumferential inner edge. The inner edge transition 2a can be rounded, i.e. have a radius. According to the exemplary embodiment, the inner edge transition 2a is designed in the form of an inner edge ridge over the entire length of the circumferential inner edge. The circumferential bearing wall 2 is formed integrally with the end wall of the housing 1, in particular of the housing pot 11, facing the first end face 31 of the outer rotor 3, and the inner edge transition 2a is formed along the inner edge between the end wall and the circumferential bearing wall 2.

[0081] The inner edge transition is preferably an inner edge burr measuring at least 300 µm in the radial and axial directions. The inner edge burr has an angle of 45° to the axial direction of the outer rotor 3.

[0082] The inner edge burr and the rotor chamfer 31a overlap each other when the outer rotor 3 is installed. This means that the inner edge burr is configured to correspond to the rotor chamfer in terms of dimensions and angle, and / or the rotor chamfer 31a is configured to correspond to the inner edge burr in terms of dimensions and angle. The outer rotor 3 preferably forms a sliding contact with the peripheral bearing wall 2 in the region of the rotor chamfer 31a.

[0083] The outer rotor 3 has no edge break on its second end face 32 or only a small second edge break 32a. The small second edge break 32a extends a maximum of 100 µm in the radial and axial directions. Preferably, the outer peripheral edge 32a of the outer rotor 3 is sharp-edged on its second end face 32.

[0084] In the event that the outer rotor 3 has a second small edge break 32a on its outer peripheral edge of the second end face 32, this corresponds to a maximum of one third of the first edge break 31a. List of reference symbols

[0085] 1 Housing 11 Housing pot 12 Housing cover 2 Peripheral bearing wall 2a Inner edge transition 21 Blind pocket 22 Blind pocket 23 Blind pocket 24 Blind pocket 24a First pocket end 24b Second pocket end 3 Outer rotor 31 First end face 31a First edge break 32 Second end face 32a Second edge break 4 Inner rotor 5 Discharge chamber 6 Inlet 7 Outlet d Inner diameter D Outer diameter R 3 Pump rotation axis R 4 Pump rotation axis inner rotor

Claims

1. A rotary pump for delivering a fluid, the rotary pump comprising: - a housing (1) featuring a delivery space (5) which the housing (1) surrounds and axially delineates on the end sides and which comprises an inlet (6) for the fluid on a low-pressure side of the rotary pump and an outlet (7) for the fluid on a high-pressure side of the rotary pump; - an inner rotor (4) which can be rotated in the delivery space (5); - an outer rotor (3) which can be rotated about a pump rotational axis (R3) in the delivery space (5) and which forms delivery cells with the inner rotor (4); and - a circumferential bearing wall (2) which is formed by the housing (1) or arranged in the housing (1) and which surrounds the outer rotor (3) and mounts it, such that it can be rotated about the pump rotational axis (R3), in a radial sliding contact, - wherein the circumferential bearing wall (2) comprises multiple blind pockets (21, 22, 23, 24) which are radially open towards the outer rotor (3) and / or the outer rotor (3) comprises multiple blind pockets (21, 22, 23, 24) which are radially open towards the circumferential bearing wall (2), wherein the blind pockets (21, 22, 23, 24) are fluidically separated from each other in the region of the sliding contact between the outer rotor (3) and the circumferential bearing wall (2), characterised in that - the blind pockets (21, 22, 23, 24) are arranged in an asymmetrical distribution over the circumference of the outer rotor (3) and / or over the circumference of the circumferential bearing wall (2) in relation to the circumferential direction, such that at least two adjacent blind pockets are at a distance from each other, over the circumference of the outer rotor and / or over the circumference of the circumferential bearing wall in relation to the circumferential direction, which is different to the other distances between the blind pockets.

2. The rotary pump according to the preceding claim, wherein the outer rotor (3) and / or the circumferential bearing wall (2) extend(s) axially beyond at least one of the blind pockets (21, 22, 23, 24), preferably each of the blind pockets (21, 22, 23, 24), towards a first end side (31) of the outer rotor (3) in its / their sliding contact, such that the respective pocket (21, 22, 23, 24) terminates in a dead end at a first end (24a) of the pocket in the region of the outer circumferential surface of the outer rotor (3) which is in sliding contact and / or in the region of the inner circumferential surface of the circumferential bearing wall (2) which is in sliding contact and is thus fluidically separated from the one or more other blind pockets on the first end side (31) of the outer rotor (3).

3. The rotary pump according to any one of the preceding claims, wherein at least one of the blind pockets (21, 22, 23, 24), preferably each of the blind pockets (21, 22, 23, 24), terminates axially in an opening on the circumferential bearing wall (2) and / or outer rotor (3) on a second end side (32) of the outer rotor (3).

4. The rotary pump according to the preceding claim, wherein the circumferential bearing wall (2) and / or the outer rotor (3) fluidically separate(s) the respective blind pocket (21, 22, 23, 24), preferably each blind pocket (21, 22, 23, 24), from the one or more other blind pockets at their end which terminates in an opening, in its / their sliding contact.

5. The rotary pump according to any one of the immediately preceding two claims, wherein the housing (1) comprises a housing cover (12) which axially delineates the delivery chamber (5) on the second end side (32) of the outer rotor (3), and wherein the housing cover (12) rests against the circumferential bearing wall (2) in an axial sealing contact and / or the housing cover (12) rests against the outer rotor (3) in an axially sealing sliding contact.

6. The rotary pump according to any one of the preceding claims, wherein the housing (1) comprises a housing cover (12) which axially delineates the delivery chamber (5) on the second end side (32) of the outer rotor (3) and forms an axial sealing gap with the circumferential bearing wall (2) and the outer rotor (3), and wherein the axial sealing gap between the housing cover (12) and the circumferential bearing wall (2) is smaller than the axial sealing gap between the housing cover (12) and the outer rotor (3).

7. The rotary pump according to any one of claims 1 to 5, wherein the outer rotor (3) comprises a chamfer (31a), in particular a rotor bevel, along its circumferential outer periphery on its first end side (31) and / or the circumferential bearing wall (2) comprises an inner edge transition (2a), in particular an inner edge burr, along its circumferential inner periphery on the first end side (31) of the outer rotor (3).

8. The rotary pump according to the preceding claim, wherein the chamfer (31a) on the outer rotor (3) overlaps with the inner edge transition (2a) on the circumferential bearing wall (2).

9. The rotary pump according to any one of the preceding claims, wherein the circumferential bearing wall (2) does not comprise a chamfer or only comprises a small second chamfer (32a) which extends at most 100 µm in the radial and axial directions along its circumferential inner periphery on the second end side (32) of the outer rotor (3) and / or the second end side (32) of the outer rotor (3) does not comprise a chamfer or only comprises a small second chamfer (32a) which extends at most 100 µm in the radial and axial directions along its circumferential outer periphery.

10. The rotary pump according to any one of the preceding three claims, wherein the outer rotor (3) comprises a second chamfer (32a) along its circumferential outer periphery on its second end side (32), and the first chamfer (31a) is at least three or four times as large in the radial and / or axial direction as the second chamfer (32a).

11. The rotary pump according to any one of the preceding four claims, wherein the outer rotor (3) comprises a chamfer (31a), in particular a rotor bevel, along its circumferential outer periphery on its first end side (31), and the chamfer (31a) measures at least 200 µm or at least 300 µm and / or at most 400 µm or 500 µm in the radial direction, and / or wherein the chamfer (31a) measures at least 200 µm or at least 300 µm and / or at most 400 µm or at most 500 µm in the axial direction.

12. The rotary pump according to any one of the preceding claims, wherein the respective blind pocket (21, 22, 23, 24) overlaps by more than 80% or more than 90% of its circumferential extent and preferably by its entire circumferential extent with either the inlet (6) only or the outlet (7) only.

13. The rotary pump according to any one of the preceding claims, wherein the rotary pump comprises four blind pockets (21, 22, 23, 24), and the blind pockets (21, 22, 23, 24) are arranged mirror-symmetrically in relation to an inner diameter (d) of the circumferential bearing wall (2) and / or an outer diameter (D) of the outer rotor (3).

14. The rotary pump according to any one of the preceding claims, wherein the blind pockets (21, 22, 23, 24) extend at least twice as far and preferably at least three times as far in the circumferential direction of the outer rotor (3) as in the radial direction of the outer rotor (3).

15. The rotary pump according to any one of the preceding claims, wherein the axial extent of the blind pockets (21, 22, 23, 24) from the first end (24a) of the pocket up to the second end (24b) of the pocket corresponds to at least 70%, preferably at least 80%, of the axial extent of the outer rotor (3) from the first end side (31) up to the second end side (32).