Pump device and method

Abstract

The invention relates to a pump device, in particular a coolant pump device, with at least one housing unit (10), with at least one bearing pin (12) which is connected to the housing unit (10), with at least one rotor (14) which is configured to rotate around the bearing pin (12) during operation, and which is configured to radially convey a fluid (44), in particular coolant, from a low-pressure area (16) of the housing unit (10) to a high-pressure area (18) of the housing unit (10), with at least one pump return chamber (22) which is fluidically connected to the high-pressure area (18), and with at least one radial bearing (26) via which the rotor (14) is mounted on the bearing pin (12). At least one fluid channel (24) is proposed which fluidically connects the pump return chamber (22) with the low-pressure area (16) and which is formed at least sectionally by an annular gap (28) of the radial bearing (26).

Description

State of the art

[0001] A pump device, in particular a coolant pump device, has already been proposed, comprising at least one housing unit, at least one bearing pin connected to the housing unit, at least one rotor configured to rotate around the bearing pin during operation, and configured to radially convey a fluid, in particular coolant, from a low-pressure area of ​​the housing unit to a high-pressure area of ​​the housing unit, at least one pump return chamber fluidically connected to the high-pressure area, and at least one radial bearing via which the rotor is mounted on the bearing pin. Disclosure of the invention

[0002] The invention relates to a pump device, in particular a coolant pump device, with at least one housing unit, with at least one bearing pin which is connected to the housing unit, with at least one rotor which is configured to rotate around the bearing pin in operation, and which is configured to convey a fluid, in particular coolant, radially and to convey it from a low-pressure area of ​​the housing unit to a high-pressure area of ​​the housing unit, with at least one pump return chamber which is fluidically connected to the high-pressure area, and with at least one radial bearing by which the rotor is mounted on the bearing pin.

[0003] At least one fluid channel is proposed which fluidically connects the pump's rear chamber to the low-pressure area, and which is formed at least partially by an annular gap of the radial bearing.

[0004] The design of the pump device according to the invention advantageously provides a long service life, since the fluid channel in particular reduces the thermal and / or mechanical stress on the axial bearing of the pump device. Advantageously, low maintenance costs can be achieved, since the axial bearing in particular is subjected to only minimal thermal and / or mechanical stress by the fluid channel, thus enabling long maintenance intervals. Advantageously, a high level of operator comfort can be provided, since air bubbles in the pump's rear chamber, which cause noise, are discharged, particularly through the fluid channel. Advantageously, a high level of operational reliability can be provided, since particles, such as abrasion particles, are flushed out of the radial gap by the fluid.

[0005] Preferably, the pump device is configured for use in a vehicle. The vehicle could be, for example, a car, a commercial vehicle, an aircraft, a train, or a similar vehicle. Alternatively, the pump device could also be used in a stationary application. The pump device is configured to circulate the fluid. The fluid is a coolant, such as cooling water. Alternatively, the fluid could also be a glycol, an oil, or the like. It is conceivable that the fluid contains additives, such as antifreeze, corrosion inhibitors, or the like. The fluid is liquid. "Configured" is understood to mean specifically designed and / or equipped.The fact that an object is set up for a specific function should be understood in particular to mean that the object fulfills and / or executes this specific function in at least one application and / or operating state.

[0006] Preferably, the rotor has several impeller blades. Preferably, the impeller blades of the rotor are configured to impart energy to the fluid. Preferably, the impeller blades of the rotor generate a fluid pressure that is configured to circulate the fluid. Preferably, the impeller blades of the rotor are configured to convey the fluid in a radial direction along the rotor. The rotor has an axis of rotation. Preferably, the rotor is configured to rotate about the axis of rotation. Preferably, the bearing pin is designed as a cylinder. Preferably, the bearing pin has a line of symmetry. Preferably, the line of symmetry of the bearing pin and the axis of rotation of the rotor are arranged at least substantially parallel to each other, preferably at least substantially coincidentally.In this context, "at least substantially" is to be understood in particular as meaning that the deviation from a given value is in particular less than 25%, preferably less than 10% and most preferably less than 5% of the given value.

[0007] Preferably, the pump device has at least one radial bearing. Preferably, the radial bearing is designed as a plain bearing. Alternatively, the radial bearing could also be designed as a rolling bearing. Preferably, the radial bearing is arranged between the rotor and the bearing pin. Preferably, the radial bearing is formed by the rotor and the bearing pin. Preferably, the radial bearing allows rotational movement of the rotor about the stationary bearing pin. Preferably, the radial bearing is configured to guide the rotor, in particular radially. Preferably, the radial bearing is configured to absorb a radial force. Preferably, the radial bearing has an annular gap. Preferably, the annular gap extends along the axis of rotation. Preferably, the annular gap has a circumferential direction. Preferably, the annular gap is closed in the circumferential direction. Preferably, the annular gap is filled with the fluid during operation.An "annular gap" shall in particular be understood to be a gap which is formed by an outer lateral surface of an inner cylinder and an inner lateral surface of an outer hollow cylinder, wherein, in particular, the inner lateral surface has a larger diameter than the outer lateral surface.

[0008] Preferably, the pump device comprises a housing unit. Preferably, the housing unit is designed in at least two parts. Preferably, the housing unit comprises a pump bowl and a pump cover. Preferably, the housing is divided at least substantially perpendicular to the axis of rotation of the rotor. Alternatively, it is conceivable that the housing is divided at least substantially parallel to the axis of rotation. Preferably, the bearing pin is firmly connected to the housing unit, in particular by a material bond or a force-fit connection. Preferably, the bearing pin is firmly connected to the pump bowl and / or to the pump cover, preferably by press fit. Preferably, the low-pressure area is limited at least by the housing unit, in particular the pump cover, and the rotor. Preferably, the high-pressure area is limited at least by the housing unit, in particular the pump cover and the pump bowl, and the rotor.The term "force-fit connection" is understood to mean, in particular, a detachable connection where a holding force between two components is preferably transmitted by a frictional force between the components. The term "material-fit connection" is understood to mean, in particular, that the mass components are held together by atomic or molecular forces, such as in soldering, welding, bonding, and / or vulcanizing.

[0009] Preferably, the pump's rear chamber is bounded at least by the housing, in particular the pump housing, and the rotor. Preferably, the pump's rear chamber is fluidically connected to the high-pressure area via a seal, for example, a throttle gap seal. Preferably, the pump device includes a drive unit. Preferably, the drive unit includes at least one rotor assembly. Preferably, the rotor assembly has permanent magnets. Preferably, the rotor assembly is arranged at least partially within the pump's rear chamber. Preferably, the rotor assembly is rigidly connected to the rotor, in particular by force-fit and / or positive locking. Preferably, the drive unit includes at least one stator assembly. Preferably, the stator assembly has at least one winding. Preferably, the at least one winding is connected to and / or integrated into the housing unit, in particular the pump housing.Preferably, the stator core, and in particular its windings, is configured to generate a magnetic field. Preferably, this magnetic field is configured to drive the rotor, and in particular the permanent magnets of the rotor core. Preferably, the stator winding and the rotor winding generate heat, particularly waste heat, during operation. The term "positive locking" is understood to mean, in particular, that adjacent surfaces of positively locked components exert a holding force on each other in the normal direction of the surfaces. In particular, the components are in geometric engagement with one another.

[0010] Preferably, the fluid channel is configured to fluidically connect the pump return chamber to an intake area of ​​the low-pressure section. The intake area is designed as the immediate vicinity of a low-pressure-side intake opening of the rotor, which is bounded by the impeller blades. In particular, the immediate vicinity of the associated intake opening is defined by all points that are less than 20 cm away from the associated intake opening, preferably 15 cm, advantageously 10 cm, and more preferably 5 cm. Preferably, the fluid channel is configured to direct the fluid from the pump return chamber, particularly along a pressure gradient in the fluid, into the low-pressure section. Preferably, the fluid channel is configured to discharge the fluid and air bubbles from the pump return chamber, which accumulate in the fluid, into the low-pressure section.

[0011] It is further proposed that the annular gap be limited by the bearing pin and the rotor. Advantageously, a low level of complexity can be achieved, since the annular gap is limited by the bearing pin and the rotor, thus eliminating the need for an additional recess and / or component. Preferably, the rotor has a sliding sleeve. Preferably, the sliding sleeve is positively connected to the rotor, in particular by press fit. Preferably, the sliding sleeve is made of a metallic material, such as bronze or brass, or the like. Preferably, the sliding sleeve is designed to slide on the bearing pin during operation. Preferably, the annular gap is limited by an outer surface of the bearing pin. Preferably, the annular gap is limited by an inner surface of the rotor, in particular the sliding sleeve.Preferably, the sliding sleeve has a relative velocity, in particular sliding velocity, compared to the stationary bearing bolt during operation.

[0012] Furthermore, it is proposed that the fluid channel has at least one gap, in particular a radial gap, which is located in the pump's rear chamber and is formed by a rotor assembly and the housing unit. Advantageously, high performance can be provided because, in particular, the rotor assembly and / or a stator assembly is cooled by the fluid. Preferably, the gap is formed by the shortest distance between the rotor assembly and the housing unit, in particular the pump housing. Preferably, the radial gap has a gap height. Preferably, the gap height of the gap is defined as the shortest distance between the rotor assembly and the housing unit, in particular the pump housing. Preferably, the rotor assembly is at least partially immersed in the fluid during operation. Preferably, the annular gap of the fluid channel is fluidically connected to the gap. Preferably, the gap is arranged along the pressure gradient between the high-pressure area and the annular gap.

[0013] Furthermore, it is proposed that the fluid channel has at least one flow channel which fluidically connects the annular gap to the low-pressure area. Advantageously, high performance can be provided because, in particular, the pressure in the pump's rear chamber can be reduced by the at least one flow channel, thus subjecting the axial bearing to only low stress. Preferably, the fluid channel has at least three flow channels which are fluidically connected to the annular gap. It is conceivable that the fluid channel has more or fewer than three flow channels.

[0014] Furthermore, it is proposed that the at least one flow channel be arranged in the housing unit, particularly in the pump cover. Advantageously, low manufacturing complexity can be achieved, since the at least one flow channel is located in the housing unit. For example, the at least one flow channel could be formed as a recess, particularly a bore, in the housing unit. It is conceivable that the at least one flow channel transitions into the annular gap. It is also conceivable that the annular gap opens into a cavity, particularly one formed by the housing, which is connected to the low-pressure area via at least one flow channel. Preferably, the flow channel extends at least substantially perpendicular to the axis of rotation. It is conceivable that the at least one flow channel is arranged in the housing unit at a minimum angle of more than 30° and less than 60° to the axis of rotation.It is also conceivable that the housing unit has, for example, a centrally arranged through-hole which fluidically connects the cavity and / or the annular gap to the low-pressure area.

[0015] It is further proposed that the at least one flow channel be arranged at least substantially radially to the rotor. Advantageous design features can be achieved, particularly since the at least one flow channel is arranged at least substantially radially to the rotor. Preferably, the at least one flow channel is arranged at least substantially perpendicular to the axis of rotation. Preferably, the at least one flow channel has a flow cross-section that is at least substantially constant in a longitudinal direction. Preferably, the flow channels are at least substantially straight. Alternatively, however, the flow channels could also be curved.

[0016] Furthermore, at least one axial bearing is proposed, which is configured to support an axial force against the housing unit and which has at least one thrust washer that at least partially confines the at least one flow channel. Advantageously, high performance can be provided, since the thrust washer, in particular, can be cooled by the fluid. Preferably, the axial bearing is designed as a plain bearing. Preferably, the axial bearing is arranged between the rotor, in particular the rotor's sliding sleeve, and the thrust washer, which is firmly, in particular positively, connected to the housing unit. Preferably, the plain bearing is formed by an end face of the rotor, in particular an end face of the sliding sleeve, and another end face of the housing unit, in particular of the pump cover or the thrust washer or the like. Preferably, the end face is configured to slide on the other end face.Preferably, the axial bearing is configured to support an axial force, such as that generated by the rotor during operation, against the housing unit, in particular the pump cover. Alternatively, the bearing could also be designed as a rolling bearing. Preferably, the at least one flow channel is formed as a longitudinal groove in the further end face of the housing unit, in particular the pump cover, which is covered by the thrust washer along a longitudinal direction of the groove. Alternatively or additionally, it is conceivable that the at least one flow channel is formed by a corrugation and / or a surface roughness between the housing unit and the thrust washer and / or between the thrust washer and the sliding sleeve. Alternatively, it is conceivable that a spacer is arranged between the thrust washer and the housing unit, in particular the pump cover, which forms at least one, preferably a plurality, flow channels.The spacer could be formed by the thrust washer.

[0017] Additionally, a method for pressure relief of the pump device is proposed. Advantageously, a long service life can be achieved because the fluid channel, in particular, reduces the thermal and / or mechanical stress on the axial bearing of the pump device. Advantageously, low maintenance costs can be achieved because the axial bearing, in particular, is subjected to only minimal thermal and / or mechanical stress by the fluid channel, thus enabling long maintenance intervals. Advantageously, a high level of operator comfort can be achieved because the fluid channel removes air bubbles from the pump's rear chamber, which cause noise. Advantageously, a high level of operational reliability can be achieved because the fluid flushes particles, such as abrasion debris, from the radial gap. Preferably, the fluid channel is continuously flowed through during operation.Preferably, pressure in the pump's return chamber is reduced by allowing the fluid to flow through the fluid channel into the low-pressure area. Preferably, at least the rotor assembly and / or the stator assembly and / or the axial bearing is cooled by forcing the fluid, particularly along the pressure gradient, through the fluid channel into the low-pressure area.

[0018] The pump device and method according to the invention are not to be limited to the application and embodiment described above. In particular, the pump device and method according to the invention may, to achieve a functionality described herein, have a different number of individual elements, components, units, and process steps than specified herein. Furthermore, values ​​within the specified limits of the value ranges stated in this disclosure are also to be considered disclosed and freely usable. drawing

[0019] Further advantages will become apparent from the following description of the drawing. The drawing illustrates an embodiment of the invention. The drawing, the description, and the claims contain numerous features in combination. A person skilled in the art will expediently consider the features individually and combine them into meaningful further combinations.

[0020] They show: Fig. 1 A schematic representation of a pump device with a housing unit, with a rotor, with a bearing pin and with a radial bearing, Fig. 2 a schematic representation of an axial bearing of the pump device and with flow channels in a pump cover of the housing unit, Fig. 3 a schematic view of the pump cover with flow channels and Fig. 4 A schematic flowchart of a procedure for pressure relief of the pump device. Description of the exemplary embodiment

[0021] The Fig. Figure 1 shows a pump device. The pump device is designed as a coolant pump device. The pump device is suitable for a vehicle. Alternatively, the pump device could also be used in a stationary application. The pump device is designed to circulate a fluid 44. The fluid 44 is in a liquid state in every operating condition. The fluid 44 is designed as a coolant. The coolant is designed as cooling water. The cooling water is designed as a mixture of water with additives. The additives could, for example, be corrosion inhibitors or similar additives. Alternatively, the coolant could also be designed as a glycol or oil or a similar liquid.

[0022] The pump device comprises a housing unit 10. The housing unit 10 comprises a pump bowl 38. The housing unit 10 comprises a pump cover 40. The pump device comprises a bearing pin 12. The bearing pin 12 is designed as a cylinder. The bearing pin 12 is connected to the housing unit 10. The bearing pin 12 has an axis of symmetry 50. The bearing pin 12 is rotationally fixed to the housing unit 10. The bearing pin 12 is pressed into the pump bowl 38. The bearing pin 12 is pressed into the pump cover 40. The line of symmetry 50 of the bearing pin 12 is arranged perpendicular to a contact surface between the pump bowl 38 and the pump cover 40. The housing unit 10 is divided perpendicular to the line of symmetry 50 into the pump bowl 38 and the pump cover 40. The pump device comprises a rotor 14. The rotor 14 is designed to rotate around the bearing pin 12 during operation. The rotor 14 has a rotation axis 52.The axis of rotation 52 is aligned with the line of symmetry 50. The rotor 14 has several impeller blades. The housing unit 10 has a low-pressure area 16. The housing unit 10 has a high-pressure area 18. The rotor 14 is configured to convey the fluid 44 radially to the rotor 14. The impeller blades of the rotor 14 are configured to convey the fluid 44 from the low-pressure area 16 to the high-pressure area 18. The fluid 44 has a higher pressure in the high-pressure area 18 than in the low-pressure area 16. The pump device has a pump return chamber 22. The pump return chamber 22 is bounded by the pump housing 38 and the rotor 14. The pump return chamber 22 is fluidically connected to the high-pressure area 18. A seal 42 is arranged between the high-pressure area 18 and the pump return chamber 22.The seal 42 is designed as a throttling gap.

[0023] The rotor 14 has a sliding sleeve 46. The sliding sleeve 46 is arranged between the rotor 14 and the bearing pin 12. The sliding sleeve 46 is pressed onto the rotor 14. The pump device has a radial bearing 26. The radial bearing 26 is designed as a plain bearing. The radial bearing 26 is formed by the sliding sleeve 46 and the bearing pin 12. The sliding sleeve 46 has an inner surface. The bearing pin 12 has an outer surface. The radial bearing 26 is formed by the inner and outer surfaces. The inner surface is designed to slide on the outer surface during operation. Alternatively, the radial bearing 26 could also be designed as a rolling bearing. The rotor 14 is supported on the bearing pin 12 via the radial bearing 26. The sliding sleeve 46 and the bearing pin 12 have a relative velocity with each other during operation. The radial bearing 26 has an annular gap 28.The annular gap 28 is bounded by the bearing pin 12 and the rotor 14. The annular gap 28 is bounded by the outer cylindrical surface. The annular gap 28 is bounded by the inner cylindrical surface. The annular gap 28 extends along the line of symmetry 50. It is conceivable that the sliding sleeve 46 has longitudinal grooves. The longitudinal grooves could run parallel to the line of symmetry 50. The longitudinal grooves could be configured to guide the fluid 44 in the axial direction. The longitudinal grooves could be configured to build up a hydrodynamic lubricating film in the radial bearing 26.

[0024] The pump assembly has a thrust bearing 20. The thrust bearing 20 is designed to support an axial force 64 against the housing unit 10. The thrust bearing 20 has a thrust washer 48. The thrust washer 48 is positively connected to the pump cover 40, cf. Fig. 3. The axial bearing 20 is formed by an end face of the sliding sleeve 46. The end face of the sliding sleeve 46 is designed to slide on the thrust washer 48 in the circumferential direction during operation.

[0025] The pump device has a fluid channel 24. The fluid channel 24 fluidically connects the pump return chamber 22 to the low-pressure area 16. The fluid channel 24 is partially formed by the annular gap 28 of the radial bearing 26. The fluid channel 24 has a gap 30. The gap 30 is designed as a radial gap. The gap 30 is located in the pump return chamber 22. The gap 30 is formed by the rotor assembly 32 and the housing unit 10. The gap 30 is formed by the rotor assembly 32 and the pump housing 38. The gap 30 is fluidically connected to the annular gap 28. The gap 30 is arranged along a pressure gradient between the high-pressure area 18 and the annular gap 28.

[0026] The Fig. Figure 2 shows a schematic representation of the axial bearing 20 of the pump device. The fluid channel 24 has two flow channels 36. The flow channels 36 are arranged in the housing unit 10. The two flow channels 36 are formed as through-holes in the pump cover 40. The through-holes are designed as through-bores. The through-bores run at a minimum angle 68 of 60° to the axis of rotation 52. The minimum angle 68 could have a value between 30° and 60°. Alternatively, a flow channel 36 could also be arranged centrally in the pump cover 40, extending parallel to the axis of rotation 52. The flow channels 36 are designed to fluidically connect the annular gap 28 to the low-pressure area 16. The flow channels 36 are designed to direct the fluid 44 into the low-pressure area 16.The flow channels 36 are designed to connect the annular gap 28 with an intake area 54 of the low-pressure area 16. The pump cover 40 and the bearing pin 12 form a cavity 62. The cavity 62 is fluidically connected to the annular gap 28 and the flow channels 36. The pump cover 40 has further longitudinal grooves 34, see [reference]. Fig. 3. The further longitudinal grooves 34 connect the annular gap 28 fluidically with the cavity 62 and / or the flow channels 36, cf. Fig. 3.

[0027] The Fig. Figure 3 shows a schematic detail view of the pump cover 40. The fluid channel 24 has three flow channels 36 arranged in an end face 66 of the pump cover 40. The fluid channel 24 could have more or fewer than three flow channels 36 arranged in the end face 66. The flow channels 36 extend radially outwards. The flow channels 36 are arranged radially to the rotor 14, cf. Fig. 1. The flow channels 36 run perpendicular to the axis of rotation 52. The flow channels 36 are straight. Alternatively, the flow channels 36 could also have curves. The flow channels 36 guide the fluid 44 from the annular gap 28 into the low-pressure area 16. The flow channels 36 are designed as grooves. The flow channels 36 are open on one side facing the thrust washer 48 (not shown). The thrust washer 48 partially limits the three flow channels 36 in an assembled state, cf. Fig. 2. The radial flow channels 36 are bounded by the pump cover 40 and the thrust washer 48. The radial flow channels 36 are designed to guide the fluid 44 in such a way that the fluid 44 cools at least the thrust washer 48.

[0028] It is conceivable that the fluid channel 24 has only the three flow channels 36 arranged in the end face 66. The fluid channel 24 can also have the flow channels 36, designed as through-holes in the pump cover 40, as an alternative or additional feature to the three radial flow channels arranged in the end face 66. It is also conceivable that the radial flow channels are formed by surface waviness and / or roughness of the end face 66. For example, the surface waviness and / or roughness of the end face 66 could form a front gap, which could be designed to discharge the fluid 44 from the annular gap 28 onto the low-pressure area 16.

[0029] The Fig. Figure 4 shows a schematic flow diagram of a procedure for pressure relief of the pump device.

[0030] In process step 56, the gap 30 is flowed through by the fluid 44. In process step 56, heat generated by the rotor assembly 32 is absorbed by the fluid 44, thereby cooling the rotor assembly 32. The fluid 44 is drawn through the gap 30 from the low-pressure area 16.

[0031] In a further process step 58, the fluid 44 is guided via the annular gap 28 to the flow channels 36. The radial bearing 26 is cooled by the fluid 44. The axial bearing 20 is also cooled by the fluid 44.

[0032] In a further process step 60, the fluid is discharged via the flow channels 36 into the low-pressure area 16. The fluid 44 is discharged into the intake area 54 of the low-pressure area 16. The axial bearing 20 is cooled by the fluid 44 as it flows through the flow channels 36.

Claims

[1] Pump device, in particular coolant pump device, comprising at least one housing unit (10), at least one bearing pin (12) connected to the housing unit (10), at least one rotor (14) configured to rotate around the bearing pin (12) during operation, and configured to radially convey a fluid (44), in particular coolant, from a low-pressure area (16) of the housing unit (10) to a high-pressure area (18) of the housing unit (10), at least one pump return chamber (22) fluidically connected to the high-pressure area (18), and at least one radial bearing (26) by means of which the rotor (14) is mounted on the bearing pin (12), characterized by at least one fluid channel (24) which fluidically connects the pump rear chamber (22) with the low-pressure area (16) and which is formed at least partially by an annular gap (28) of the radial bearing (26). [2] Pump device according to one of the preceding claims, characterized by , that the annular gap (28) is limited by the bearing bolt (12) and the rotor (14). [3] Pump device according to one of the preceding claims, characterized by , that the fluid channel (24) has at least one gap (30), in particular a radial gap, which is arranged in the pump rear chamber (22) and which is formed by a rotor package (32) and the housing unit (10). [4] Pump device according to one of the preceding claims, characterized by , that the fluid channel (24) has at least one flow channel (36) which fluidically connects the annular gap (28) with the low-pressure area (16). [5] Pump device according to claim 4, characterized by , that at least one flow channel (36) is arranged in the housing unit (10). [6] Pump device according to claim 4 or 5, characterized by, that at least one flow channel (36) is arranged at least substantially radially to the rotor (14). [7] Pump device according to any one of claims 4 to 6, characterized by at least one axial bearing (20) which is designed to support an axial force (64) against the housing unit (10) and which has at least one thrust washer (48) which at least partially limits the at least one flow channel (36). [8] Method for pressure relief of the pump device according to one of the preceding claims.

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