Modular System of an Axially Integrated Pump Structure

Abstract

A modular system for a pump structure for the axial integration of a selection of electric drive assemblies (1) at a selection of pump assemblies (2) and a shaft bearing assembly (3) which includes a pump shaft (31) and a shaft bearing (32) with at least two rolling bearing sets, the shaft bearing (32) supporting the pump shaft (31) between a motor rotor (1) of the electric drive assembly (1) and a pump rotor (21) of the pump assembly (2) at a pump housing (20) of the pump assembly (2); wherein the selection of pump assemblies (2) jointly comprises a collar portion (23) at the pump housing (20) which accommodates the shaft bearing (32) in a through-hole of the pump housing (20) and protrudes to an accommodation side for an electric drive unit (1); and the selection of pump assemblies (2) differs with respect to the pump rotor (21) and/or a pump chamber (22); the selection of drive assemblies (1) jointly comprises a motor rotor (11) which is formed at a radially external section in the shape of a rotor cup (13), the rotor cup (13) radially encircling and axially intersecting the collar portion (23) that each pump housing (20) of the selection of drive assemblies (1) jointly comprises; and the selection of drive assemblies (1) differs with respect to a stator (12); and wherein for each combination of the selection of electric drive assemblies (1) and the selection of pump assemblies (2), at least one radial dimension of the pump shaft, the shaft bearing, the collar portion (23) and/or the rotor cup (13) are the same.

Claims

1. A modular system for a pump structure for the axial integration of an electric drive assembly at a pump assembly including: a selection of electric drive assemblies with different drive capacities; a selection of pump assemblies with different volumetric capacities and/or different configurations; and a shaft-bearing-assembly including a pump shaft and a shaft bearing with at least two rolling bearing sets, the shaft bearing supporting the pump shaft between a motor rotor of the electric drive assembly and a pump rotor of the pump assembly at a pump housing of the pump assembly; wherein the selection of pump assemblies jointly comprises a collar portion at the pump housing which accommodates the shaft bearing in a through-hole of the pump housing and protrudes to an accommodation side for an electric drive unit; and the selection of pump assemblies differs with respect to the pump rotor and/or a pump chamber; the selection of drive assemblies jointly comprises a motor rotor which is formed at a radially external section in the shape of a rotor cup, the rotor cup radially encircling and axially intersecting the collar portion that each pump housing of the selection of drive assemblies jointly comprises; and the selection of drive assemblies differs with respect to a stator; and wherein for each combination of the selection of electric drive assemblies and the selection of pump assemblies, at least one radial dimension of the pump shaft, the shaft bearing, the collar portion and/or the rotor cup are the same.

2. The modular system according to claim 1, wherein for each combination out of the selection of electric drive assemblies and the selection of the pump assemblies, a collar portion with the same outer diameter is provided on the side of the pump housing and a rotor cup with the same inner diameter is provided on the side of the motor rotor.

3. The modular system according to claim 1, wherein for each combination out of the selection of electric drive assemblies and the selection of the pump assemblies, on the side of the pump housing, a collar portion with the same inner diameter, the same shaft bearing and a pump shaft with the same outer diameter are provided.

4. The modular system according to claim 1, wherein for each combination out of the selection of electric drive assemblies and the selection of the pump assemblies, a motor chamber with the same inner circumference is formed in the pump housing.

5. The modular system according to claim 4, wherein the motor chamber is closed to one axial side of the pump housing by a motor cover with an integral pin-fin heat sink in which control electronics may be accommodated for an electric drive assembly.

6. The modular system according to claim 4, wherein at least one part of the pump housing that includes the through-hole and the collar portion, and/or the motor cover is made of a material suitable for impact extrusion, preferably cold impact extrusion.

Description

[0023] The invention will be explained in greater detail hereinafter with reference to drawings relating to various embodiments arising from various selection combinations out of the assemblies of the modular system. In the drawings:

[0024] FIG. 1 shows a water pump, of which the electric drive is configured as a dry runner;

[0025] FIG. 2 shows a water pump, of which the electric drive runs in a separate cooling medium which is separate from the conveyed cooling water;

[0026] FIG. 3 shows a slush/air pump, of which the electric drive is configured as a dry runner;

[0027] FIG. 4 shows an oil pump, of which the electric drive is configured as a dry runner;

[0028] FIG. 5 shows an oil pump, of which the electric drive is configured as a wet runner; and

[0029] FIG. 6 shows a vacuum pump, of which the electric drive is configured as a dry runner.

[0030] FIG. 1 shows a first embodiment of a pump consisting of a modular system in the form of a water pump, of which the electric drive is designed as a dry runner. The pump assembly 2 is a centrifugal pump of the radial pump type. On the right-hand side, the pump assembly 2 is only partially illustrated, wherein a pump cover has been removed which radially surrounds and axially delimits a pump chamber 22. In this embodiment, the pump rotor 21 is designed as a radial impeller 21a and has a central intake opening, through which a conveyor flow of a cooling water is drawn in and accelerated radially into the pump chamber 20. Around an exit region of the radial impeller 21a, a spiral housing portion, not illustrated, is provided in the pump cover, not illustrated, through which the conveyor flow is tangentially discharged through a pump outlet. Such generally known details relating to the pump assembly 2 of the radial pump type are not stated further in order to reduce the length of the disclosure.

[0031] A rear side of the pump chamber 22 behind the impeller 21a is formed by the illustrated part of a pump housing 20. The pump housing 20 has a through-hole for a pump shaft 31 which is sealed with respect to the pump chamber 22 by means of a shaft seal 33. The pump shaft 31 extends from the impeller 21a through the through-hole of the pump housing 20 to an electric drive assembly 1 and is mounted on the pump housing 20 by means of a single shaft bearing 32. The shaft bearing 32 has two rolling bearing sets with spherical rolling bodies in order to be able to absorb radial and axial forces and also tilting moments of the pump shaft 31 within a single shaft bearing 32. The shaft bearing 32 is fitted into a collar portion 23 of the pump housing 20. The collar portion 23 protrudes concentrically with respect to the through-hole of the pump housing 20 to the side of the electric drive assembly 1.

[0032] The electric drive assembly 1 comprises a motor rotor 11 and a stator 12 as well as control electronics 14. On the same side, the pump housing 20 has a cylindrical outer wall which surrounds a motor chamber 10 for accommodating the electric drive assembly 1. The outer housing wall of the pump housing 20 extends concentrically with respect to the collar portion 23 and so an annular volume for accommodating the stator 12 of the electric drive assembly 1 is provided in the motor chamber 10. An outer circumferential edge of the stator 12 is in contact with a step portion of an inner surface of the motor chamber 10 and is thus radially and axially fixed.

[0033] The motor rotor 11 is fixed on a free end of the pump shaft 31 which projects out of the collar portion 23. The motor rotor 11 has, at a radially outer portion, a rotor cup 13 which axially intersects the collar portion 23 of the pump housing 20 and encircles same radially outside. An axial dimension and position of the rotor cup 13 corresponds to a facing inner surface of the stator 12. The rotor cup 13 serves as a magnet carrier for the rotor poles. Therefore, a hollow cylinder which corresponds substantially to the outer diameter of the collar portion 23 plus a spacing gap remains within the rotor cup 13.

[0034] The windings of the field coils of the stator 12 extend to the left and right of the stator yoke into the motor chamber 10. The pump housing 20 is open on an axial side of the motor chamber 10. The opened side of the pump housing 20 is closed by means of a motor cover 24. The motor cover 24 has, on an outer side, a multiplicity of parallel-protruding pins and forms a so-called pin-fin heat sink. On the inner side, the motor cover 24 has a surface which is in thermal contact with control electronics 14 of the electric drive assembly 1. In particular, the control electronics 14 has electronic modules or power electronics, such as e.g. capacitors and transistors, which are wired on a printed circuit board and the printed circuit board is in surface contact with the accommodation surface of the motor cover 24. Arranged between the pump housing 20 and the motor cover 24 is a connector which is illustrated on the upper housing side and guides lines to an electric power supply.

[0035] FIG. 2 shows a second embodiment of a pump of the modular system in the form of a coolant pump, of which the electric drive assembly is cooled with the aid of a bath in a separate medium. The pump assembly 2 corresponds substantially to that of the first embodiment and has, again, the radial impeller 21a as the pump rotor 21. In the view provided in FIG. 2, a part of the pump housing 20 which surrounds the pump chamber 22 is not described further in order to reduce the length of the disclosure to the essential aspects of the invention.

[0036] On a rear side of the radial impeller 21a, the pump housing 20 has a pressure equalisation chamber 26, over the circumference of which a pressure equalisation membrane 27 is tensioned. A rear side of the pressure equalisation chamber 26 is connected to the motor chamber 10 via a bore. The motor chamber 10 is filled with a dielectric cooling medium which is introduced into the pump housing 20 through a closable opening. The dielectric cooling medium surrounds the field coils of the stator 12 and discharges waste heat from the power loss of the stator via the pump housing 20 to the environment and in particular to a conveyor flow in the pump chamber 22 of the pump assembly 2.

[0037] Pressure fluctuations which arise in the closed volume of the motor chamber 10 by reason of the temperature fluctuations in the electric drive assembly 1 are transmitted by the pressure equalisation chamber 26 via the pressure equalisation membrane 27 to the pump chamber 20 and so a pressure equilibrium is achieved between the motor chamber 10 and the pump chamber 22.

[0038] The first embodiment and the second embodiment have the same pump shaft 31 and the shaft bearing 32. Furthermore, parts of the pump housing 20 for accommodating the electric drive assembly 1, such as the collar portion 23 and an outer wall of the pump chamber 10, as well as the motor cover 24, correspond with one another. Likewise, an inner diameter of the rotor cup 13 on the motor rotor 11 corresponds to that of the preceding embodiments.

[0039] FIG. 3 shows a first embodiment of a pump consisting of the modular system in the form of a slush pump or air pump, of which the electric drive assembly is designed as a dry runner. The pump rotor 21 is designed as a peripheral wheel 21b. The pump housing 20 forms an annular channel as a pump chamber 22 around the peripheral wheel 21b. A pump inlet and a pump outlet are arranged adjacent one another on the circumference of the annular channel of the pump chamber 22. This pump type can convey liquid and also gaseous fluids as well as a mixture of the two phases and is used e.g. for a fuel cell.

[0040] In comparison with the preceding embodiments, the stator 12 of the electric drive assembly 1 has a smaller drive capacity. The stator 12 of this embodiment has been configured in such a way that an axial dimension including the field coils has been reduced in comparison with the preceding embodiments. However, parts of the pump housing 20 for accommodating the electric drive assembly 1, such as the collar portion 23 and an outer wall of the pump chamber 10, as well as the motor cover 24, also correspond to those of the preceding embodiments. Likewise, an inner diameter of the rotor cup 13 on the motor rotor 11 corresponds to that of the preceding embodiments. The shaft bearing 32 and a blank as an initial body of the pump shaft 31 are identical.

[0041] FIG. 4 shows a fourth embodiment of a pump consisting of the modular system in the form of an oil pump, of which the electric drive assembly 1 is designed as a dry runner. A shaft seal 33 for sealing the dry-running drive assembly 1 is arranged behind the shaft bearing 32 in the collar portion 23 and so the shaft bearing 32 is lubricated by the conveyed oil.

[0042] The pump assembly 2 is a displacement pump of the gerotor type. The pump rotor 21 is designed as a gerotor inner element 21c, of which the outer rotor toothing is in meshing engagement with an inner rotor toothing of a rotatable gerotor outer element 28. The pump cover 25 has a central pump inlet. The pump outlet is not illustrated in this sectional view. Moreover, further details of the pump assembly 2 have not been described further in order to reduce the length of the disclosure to essential features of the invention.

[0043] The electric drive assembly 1 of the fourth embodiment has a larger drive capacity, in particular a high drive torque, corresponding to the requirement of a displacement pump, in comparison with the preceding embodiments. The stator 12 of the electric drive assembly 1 of this embodiment has been configured in such a way that an axial dimension including the field coils is longer in comparison with the preceding embodiments. Accordingly, a diameter of the field coils of the stator 12 and an axial dimension of the magnetic poles on the rotor cup 13 are larger than in the case of the preceding embodiments. However, an axial dimension of parts of the pump housing 20 for accommodating the electric drive assembly 1, such as the collar portion 23 and an outer wall of the pump chamber 10, as well as the motor cover 24, also correspond to those of the preceding embodiments. Likewise, an inner diameter of the rotor cup 13 on the motor rotor 11 corresponds to that of the preceding embodiments. The shaft bearing 32 and a blank as an initial body of the pump shaft 31 are identical.

[0044] FIG. 5 shows a fifth embodiment of a pump consisting of the modular system in the form of an oil pump, of which the electric drive assembly 1 is designed as a wet runner. The pump assembly 2, details of which are not discussed further in order to reduce the length of the disclosure is, again, a gerotor pump comprising a gerotor inner element 21c as the pump rotor 21 and a rotatable gerotor outer element 28 which correspond substantially to those of the fourth embodiment.

[0045] The drive capacity of the electric drive assembly 1 corresponds substantially to that of the fourth embodiment, but it is not sealed by means of a shaft seal 33 and therefore is in contact with the conveyed oil. The motor cover 24 differs from the fourth embodiment in that it delimits the control electronics 14 from the oil in the motor chamber 10. In turn, the control electronics 14 can be covered with respect to the outer side by a cover, not illustrated. The shaft bearing 32 and a blank as an initial body of the pump shaft 31 are identical.

[0046] FIG. 6 illustrates a sixth embodiment of a pump consisting of the modular system in the form of an oil-free, dry-running vacuum pump. The pump assembly 2 consists of a rotary piston 29 which is moved in an oscillating manner in the pump chamber 22 and at the same time, on the one hand, draws in air through an inlet and, on the other hand, displaces air and pushes out same through pressure valves into an outlet.

[0047] The rotary piston 29 is driven by means of a crank pin on a rotary plate 21d which engages into a long hole in the rotary piston 29. The pump rotor 21 of the sixth embodiment is thus designed as a rotary plate 21d comprising a crank pin.

[0048] The stator 12 of the electric drive assembly 1 in the sixth embodiment has a smaller drive capacity in comparison with the fourth and fifth embodiment of an oil pump. The stator 12 of this embodiment has been configured in such a way that an axial dimension including the field coils has been reduced in comparison with the fourth and fifth embodiments. However, parts of the pump housing 20 for accommodating the electric drive assembly 1, such as the collar portion 23 and an outer wall of the pump chamber 10, as well as the motor cover 24, also correspond to those from preceding embodiments. Likewise, an inner diameter of the rotor cup 13 on the motor rotor 11 corresponds to that of the preceding embodiments. The shaft bearing 32 and a blank as an initial body of the pump shaft 31 are identical.

[0049] A common aspect of all embodiments of the pumps consisting of the modular system is that the electric drive assembly 1, the pump housing 20 of the pump assembly 2 and the shaft bearing assembly 3 are arranged in an integrated manner in the pump structure such that they axially intersect one another. The same sequence of components of the assemblies is always provided in the radial direction from inside to outside, namely the pump shaft 31, the shaft bearing 32, the collar portion 23, the rotor cup 13, the stator 12 and an outer wall of the pump housing 20 which defines the motor chamber 10.

[0050] Whether a shaft seal 33 is used and whether the shaft seal 33 is arranged in front of or behind the shaft bearing 32 can be varied by positioning the shaft seal 33 in the standard collar portion 23 for different types of electric drive assemblies 1, such as dry runners and wet runners, using assembly procedures without having to manufacture different moulded parts for the pump housing. The shaft bearing 32 and a pump shaft 31 or a blank thereof having the same diameter can be provided in each pump from a selection combination of the assemblies consisting of the same components.

[0051] In order to achieve the largest possible number of common components for a universal integration of individual selection combinations amongst the assemblies, a portion of the pump housing 20 which delimits the pump chamber 22 and the motor chamber 10 and comprises the collar portion 23 and a step portion, on the inner surface of which the stator 12 is axially fixed, is designed having the same radial dimensions and is manufactured as a standard impact-extruded part with or without the feature of a pin-fin cooler. Likewise, the motor cover 24 is designed for several embodiments having the same dimensions and is manufactured as a standard impact-extruded part, wherein for liquid-cooled electric drive assemblies 1 of the wet runner type an integrated pin-fin heat sink to the outer side can be omitted. Furthermore, the motor rotor 11 comprising the rotor cup 13 having the same radial dimensions is formed at least prior to the provision of rotor poles with the same inner diameter and is manufactured as a standard deep-drawn part or sintered part having good magnetic properties.

[0052] The adaptation to the electric drive assemblies 1 is thus effected by means of a length of the axial dimension of the pump housing 20 and the rotor cup 13 and by providing the magnetic poles in dependence upon the field coils of a selected stator 12. Moreover, a configuration of the pump assembly 2 in dependence upon the selected combination of the pump rotor 21 and pump chamber 22 in relation to the pump housing 20 is standardised by implementing specific features, such as a pump inlet and pump outlet or a spiral housing, not on the side of the aforementioned standard portion of the pump housing 20 but instead on the side of an individual pump cover 25.

LIST OF REFERENCE SIGNS

[0053] 1 electric drive assembly

[0054] 2 pump assembly

[0055] 3 shaft bearing assembly

[0056] 10 motor chamber

[0057] 11 motor rotor

[0058] 12 stator

[0059] 13 rotor cup

[0060] 14 control electronics

[0061] 20 pump housing

[0062] 21a radial impeller

[0063] 21b peripheral wheel

[0064] 21c gerotor inner element

[0065] 21d rotary plate with crank pin

[0066] 22 pump chamber

[0067] 23 collar portion

[0068] 24 motor cover

[0069] 25 pump cover

[0070] 26 pressure equalisation chamber

[0071] 27 pressure equalisation membrane

[0072] 28 gerotor outer element

[0073] 29 rotary piston

[0074] 31 pump shaft

[0075] 32 shaft bearing

[0076] 33 shaft seal