WO2018033273A1

WO2018033273A1 - Pump assembly

Info

Publication number: WO2018033273A1
Application number: PCT/EP2017/064621
Authority: WO
Inventors: Chen Zhou; Guido Bernd Finnah; David Paul THIBAULT; Martin Hiller; Dieter Amesoeder; Thomas Frahammer; Marian Kacmar; Dominik ROCKER; Raed Hamada; Thorsten Stoeberl; Yihao Zhu; Joerg Engelhardt
Original assignee: Robert Bosch Gmbh
Priority date: 2016-08-18
Filing date: 2017-06-14
Publication date: 2018-02-22
Also published as: EP3500732A1; CN109563739A; KR20190034673A; CN109563739B; EP3500732B1; DE102016215474A1

Abstract

Pumping assemblies are already known, comprising a drive shaft and a rotor rotatably arranged in a pump stator and driven by the drive shaft. The drive shaft has an oblique sliding plane which cooperates with the rotor and which permits the rotor to wobble about a drive axis of the drive shaft by the rotor axis thereof. The rotor has a toothing on the end side thereof facing away from the drive shaft, which engages with a toothing formed on the pump stator. Work spaces are formed between the toothing of the rotor and the toothing of the pump stator in order to pump pumping media. The drive shaft, the rotor and the pump stator are individual pump components which, in cooperation, have determined properties to fulfill, such as flow rate, effectiveness and pressure build-up, within determined tolerances. Whether the pump components together can fulfill these required properties can only be tested in a function test on the finished product, i.e. after the complete construction of the pump assembly. For the pump assembly according to the invention, the production costs are reduced. According to the invention, the drive shaft (2) is arranged in a bearing bushing (24) having a shoulder (31) protruding in a radial direction in relation to the drive axis (7), on which shoulder the pump stator (3) is retained by means of at least one retaining means (27).

Description

Description title

delivery unit

State of the art

The invention relates to a delivery unit of the type of

Main claim.

It is already known a delivery unit from DE102014209140 AI, with a drive shaft and driven by the drive shaft, rotatably mounted in a pump stator rotor. The drive shaft has one with the rotor

cooperating inclined sliding plane, which causes the rotor with its rotor axis to wobble about a drive shaft of the drive shaft. The rotor has on its side facing away from the drive shaft end face a toothing, with a on the

Pump stator trained teeth meshes. Between the teeth of the rotor and the toothing of the pump stator working spaces for conveying pumped media are formed. The drive shaft, the rotor and the pump stator are individual pump components that have to fulfill certain characteristics such as delivery rate, efficiency and pressure build-up within certain tolerances. Whether the pump components can jointly fulfill these required properties can only be tested in a functional test on the finished product, ie after complete assembly of the delivery unit.

ADVANTAGES OF THE INVENTION The delivery unit according to the invention with the characterizing features of the invention

Main claim has the advantage that the drive shaft, the rotor and the pump stator form a pump unit that can be tested by itself already on the fulfillment of the necessary properties. In this functional test, a drive of a test stand is used to drive the pump unit. The pump unit is achieved by the drive shaft is arranged in a bearing sleeve having a projecting in the radial direction with respect to the drive axis shoulder at which the pump stator is held by means of at least one holding means. If the pump unit does not fulfill the required properties in the functional test, the pump unit is reworked in a post-processing step. This repair can be done immediately after the assembly of the pump unit and not only after the assembly of pump unit and drive, so not only after completion of the entire delivery unit. This will be the

Reduced production costs.

The measures listed in the dependent claims are advantageous

Further developments and improvements of the main claim

Delivery unit possible.

Advantageously, the at least one holding means a positive and / or non-positive connection between the shoulder of the bearing sleeve and the

Achieve pump stator, in particular a latching, clamping, pressing or

Screw connection.

According to a first embodiment, the at least one retaining means is formed by a deformed annular collar, which is provided on the shoulder of the bearing sleeve and engages behind the pump stator. After a second

Embodiment, the at least one holding means is formed by a retaining ring, which is arranged on the side facing away from the rotor of the pump stator and engages behind the shoulder of the bearing sleeve with latching means. According to a third embodiment, the pump stator of a housing of the

Delivery units are pressed against the shoulder of the bearing sleeve.

It is also advantageous, when the bearing sleeve is attached to the pump stator, that the bearing sleeve is arranged concentrically to the drive axis of the drive shaft. In this way, an alignment or centering of the components of

Pump unit achieved to each other, so that the radial forces to the rotating

Components can be reduced and thereby the wear and the resulting by the internal leakage reduction of the pump efficiency can be minimized.

It is very advantageous if at least one sealing means is provided which seals a gap between the bearing sleeve and the drive shaft. In this way, the in the form of returning medium to the suction of the delivery unit occurring internal losses between high pressure side and low pressure side decreases and increases the pump efficiency. Furthermore, it is advantageous if the bearing sleeve with three stages sections

having different diameters, wherein at the two outer

Step sections in each case a sliding bearing and at the middle step portion, the at least one sealing means is provided. In this way, the running surface for the sealant can be produced particularly inexpensively.

Moreover, it is advantageous if the bearing sleeve is made conical, as this simplifies the deep drawing of the bearing sleeve. In order to obtain a constant sealing gap in the axial direction despite the taper of the bearing sleeve, the

Drive shaft be performed conically in a corresponding manner. Due to the constant sealing gap seen in the axial direction, a good seal is achieved and a hydrodynamic lubricant film is produced.

It is advantageous if the bearing sleeve made of a stainless steel and the drive shaft, the rotor and the pump stator of a plastic, in particular a thermosetting plastic, are made. This material selection makes the delivery unit suitable for pumping aqueous urea solutions.

It is also advantageous if the drive shaft with a rotatably mounted

Magnet armature is coupled, which surrounds the drive shaft annular and is rotatably mounted on the bearing sleeve. The bearing sleeve provides in this way

Sliding bearing for the drive shaft and a slide bearing for the armature ready.

It is particularly advantageous if the pump stator faces the rotor

Upper layer and a rotor facing away from the carrier layer, wherein the upper layer is made of a thermosetting plastic and the carrier layer made of a thermoplastic. Due to the more flexible plastic of the carrier layer, the stator can adapt better to the rotor, so that gaps between the teeth of rotor and pump stator are reduced. It is also advantageous if the drive shaft faces one of the bearing sleeve

Upper layer and a bearing sleeve facing away from the carrier layer, wherein the Upper layer of a thermosetting plastic and the carrier layer is made of a thermoplastic. In this way, the dimensional accuracy of the drive shaft is improved.

drawing

Three embodiments of the invention are shown in simplified form in the drawing and explained in more detail in the following description. Fig.l shows a sectional view of a delivery unit with a

Pump unit according to the invention according to a first embodiment,

2 is an exploded view of the delivery unit according to Fig.l,

3 shows the pump unit according to the first embodiment,

4 shows a pump unit according to a second embodiment,

5 is an exploded view of the pump unit according to Fig.4 and

6 shows a pump unit according to a third embodiment.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS FIG. 1 shows a sectional view of a delivery unit with a pump unit according to the invention according to a first exemplary embodiment.

The delivery unit according to the invention serves to convey fluid media. The delivery unit 1 comprises a drive shaft 2 and a driven by the drive shaft 2, in a pump stator 3 rotatably mounted rotor 4. Die

Drive shaft 2, the pump stator 3 and the rotor 4 are made for example of a plastic, in particular a thermosetting plastic. The drive shaft 2 has a cooperating with the rotor 4 inclined sliding plane 5, which can tumble the rotor 4 with its rotor axis 6 about a drive shaft 7 of the drive shaft 2. The inclined sliding plane 5 is provided for example on an end face of a shoulder portion 10 of the drive shaft 2. The rotor 4 has on its end facing away from the drive shaft 2 a toothing 11 which meshes with a formed on the pump stator 3 teeth 12, wherein between the teeth 11 of the rotor 4 and the teeth 12 of the pump stator 3 working spaces for conveying the pumped medium are formed. The pump stator 3 can be made of a single material or, alternatively, a top layer facing the rotor 4 and a rotor 4 facing away from the rotor

Carrier layer, wherein the upper layer of a thermoset and the

Carrier layer is made of a thermoplastic.

Furthermore, magnets 14 are provided by means of which the drive shaft 2 in

Cooperation with a magnetic field of an electrical winding 15 of a stator 16 is driven. The stator 16 is designed, for example, as a laminated stator core.

The magnets 14 are rotatably mounted on a drive shaft 7 about the

Magnet armature 17 is provided, which surrounds the drive shaft 2 annular and is mechanically connected to the drive shaft 2. For example, the armature 17 is positively connected, according to the embodiment via a toothing 18,19, with the armature 17. The magnet armature 17 has a passage opening 22 for receiving a portion of the drive shaft 2. In the through hole 22, the toothing 18 is formed, which interacts mechanically with the toothing 19 of the drive shaft 2. The teeth 18,19 is formed as a straight toothing, for example as involute or circular arc. As a result, the drive shaft 2 in the axial direction with respect to the drive shaft 7 relative to the armature 17 is displaceable, so that the weight of the magnets 14 is mounted on the support plate 30 on the bearing sleeve 24 and not on the

Drive shaft 2 acts. The magnet armature 17 has a magnetic carrier 20 holding the magnets 14, which is made of plastic and the magnets 14 in the radial direction on the drive shaft 2 facing the inside, in the circumferential direction between the magnets 14 and in the axial direction on the end faces encloses.

The hohzylindrförmige magnet armature 17 is surrounded by the stator 16 and arranged in a first, for example cup-shaped housing portion 23. The stator 16 is provided, for example, on the outer circumference of the first housing portion 23.

For supporting the drive shaft 2, a bearing sleeve 24 is provided, which extends into the passage opening 22 of the armature 17 and in which the drive shaft 2 is rotatably mounted. The bearing sleeve 24 is for example cylindrical and / or sheet-shaped. Accordingly, the portion of the drive shaft 2, which is mounted in the bearing sleeve 24, also formed cylindrical. Alternatively, the the Bearing sleeve 24 is slightly conical and the corresponding portion of the drive shaft 2 with the same angle also be made conical.

The bearing sleeve 24 is made of a sheet, which consists for example of stainless steel. The drive shaft 2 is in the axial direction with respect to the drive shaft 7 with the shoulder portion 10 of the bearing sleeve 24 out. The drive shaft 2 may be made of a single material or, alternatively, a top layer facing the bearing sleeve 24 and a carrier layer facing away from the bearing sleeve 24, wherein the top layer is made of a thermosetting plastic and the carrier layer is made of a thermoplastic.

For mounting the magnet armature 17, a bearing ring 25 is attached to an end face of the armature 17, which has a sleeve portion 28 and a projecting in the radial direction with respect to the drive shaft 7 disc portion 29. The sleeve portion 28 of the bearing ring 25 is rotatably mounted on the bearing sleeve 24. The disk portion 29 of the bearing ring 25 forms with an applied to the housing portion 23 supporting disk 30 an axial sliding bearing. The support disk 30 is

For example, made of stainless steel and the bearing ring 25 made of high temperature resistant thermoplastic material, especially PEEK.

According to the invention, the drive shaft 2, the pump stator 3, the rotor 4 and the bearing sleeve 24 form a pump unit 26. To form the pump unit 26, the bearing sleeve 24 at its end facing the rotor 4 has a shoulder 31 which is annular disk-shaped in the radial direction with respect to the drive axis 7 protrudes and on which the pump stator 3 is held by means of at least one holding means 27.

According to the first and second embodiments of the pump unit 26, the at least one holding means 27 is a positive and / or non-positive

Connection between the shoulder 31 of the bearing sleeve 24 and the pump stator 3 ago, for example, a latching, clamping, pressing or screw connection.

According to the first embodiment of the pump unit 26, the at least one retaining means 27 is formed by a deformed annular collar 46, which is provided on the shoulder 31 of the bearing sleeve 24 and engages behind the pump stator 3. Through the shoulder 31 and the annular collar 46 of the bearing sleeve 24, a receiving portion 32 for receiving the pump stator 3 is formed. The bearing sleeve 24 is so on

Pump stator 3 attached that the bearing sleeve 24 concentric with the drive axis. 7 the drive shaft 2 is arranged. The pump stator 3 and the receiving portion 32 of the bearing sleeve 24 enclose a space in which the shoulder portion 10 of the drive shaft 2 and the rotor 4 are arranged. The shoulder 31 of the bearing sleeve 24 abuts against the support plate 30.

Furthermore, a second, for example, ceiling-shaped housing portion 34 is provided, which closes the first housing portion 23, the support plate 30 with at least one holding portion 36 against a shoulder 35 of the first

Housing portion 23 and the pump stator 3 against the shoulder 31 of the bearing sleeve 24 presses. The first housing section 23 and the second housing section 34 together form a housing of the delivery unit 1.

The second housing portion 34 includes, together with the support plate 30 and the receiving portion 32 of the bearing sleeve 24 an annular space 37, in which an example, annular sealing element 38 is arranged.

In the drive shaft 2, a channel 40 is formed in which a spring 41 is provided, which is biased at its one end by a projecting into the channel 40 bearing pin 42 and presses the drive shaft 2 against the rotor 4 at its other end. The bearing pin 42 is fastened, for example, to a bottom 43 of the cup-shaped first housing section 23. Between the spring, for example, a

Coil spring is, and the bearing pin 42 may be provided a ball 44 which rotates with the spring 41 and the drive shaft 2 and is a low-wear connection to the bearing pin 42.

The channel 40 is, for example, a through-passage extending in the axial direction, which extends from an end face facing away from the rotor 4 to the front side facing the rotor 4 with the oblique sliding plane 5 and fluid to the suction side

Leading working chambers or discharges pressure side.

2 shows an exploded view of the delivery unit according to Fig.l.

In the view according to FIG. 2, the parts which are identical or functionally equivalent to the view of FIG. 1 are identified by the same reference numerals.

3 shows the pump unit according to the first embodiment. 4 shows a pump unit according to the second embodiment.

In the pump unit according to the second embodiment, the at least one retaining means 27 is formed as a separate retaining ring 47, which is arranged on the side facing away from the rotor 4 of the Pumpenstators 3 and the shoulder 31 of the bearing sleeve 24 with locking means 48, for example, resilient locking arms behind engages. The retaining ring 47 is made of stainless steel, for example. 5 shows an exploded view of the pump unit according to Fig.4.

6 shows a pump unit according to a third embodiment.

In the pump unit 26 according to the third embodiment, at least one sealing means 50 is provided at a gap 51 between the bearing sleeve 24 and the drive shaft 2, which seals the gap 51.

The bearing sleeve 24 has, for example, four step sections 24.1, each with a different diameter. At the two outer step portions 24.1 of the bearing sleeve 24, a sliding bearing is formed in each case. Seen in the axial direction between these plain bearings, the at least one sealing means 50 is provided on the drive shaft 2 in a groove 53. The sealing means 50 comprises, for example, a PTFE sealing ring, which cooperates in the groove 53 with an EPDM O-ring. Between the shoulder 31 of the bearing sleeve 24 and the pump stator 24, a shim, not shown, may be provided to determine the gap between the drive shaft 2 and the bearing sleeve 24. This gap size is important to produce a hydrodynamic sliding film on the rotating drive shaft 2.

Claims

Expectations

1. Conveyor unit (1) with a drive shaft (2) and a rotor (4) driven by the drive shaft (2) and rotatably arranged in a pump stator (3), the drive shaft (2) having an inclined one which interacts with the rotor (4).

Has a sliding plane (5) which causes the rotor (4) with its rotor axis (6) to tumble around a drive axis (7) of the drive shaft (2), the rotor (4) having teeth on its end face facing away from the drive shaft (2). 11) which meshes with a toothing (12) formed on the pump stator (3), working spaces being formed between the toothing (11) of the rotor (4) and the toothing (12) of the pump stator (3), characterized in that in that the drive shaft (2) is arranged in a bearing sleeve (24) which has a shoulder (31) which projects in the radial direction with respect to the drive axle (7) and on which the pump stator (3) is held by means of at least one holding means (27). .

2. Delivery unit according to claim 1, characterized in that the at least one holding means (27) achieves a positive and / or non-positive connection between the shoulder (31) of the bearing sleeve (24) and the pump stator (3), in particular a latching, clamping -, press or screw connection.

3. Delivery unit according to one of claims 1 or 2, characterized in that the at least one holding means (27) is a formed annular collar (46) which is provided on the shoulder (31) of the bearing sleeve (24) and the pump stator (3). engages behind, or comprises a retaining ring (47) which is arranged on the side of the pump stator (3) facing away from the rotor (4) and engages behind the shoulder (31) of the bearing sleeve (24) with locking means (48).

4. Conveyor unit according to one of the preceding claims, characterized

characterized in that the bearing sleeve (24) is attached to the pump stator (3) in such a way that the bearing sleeve (24) is arranged concentrically to the drive axis (7) of the drive shaft (2).

Conveyor unit according to one of the preceding claims, characterized

characterized in that at least one sealing means (50) is provided which seals a gap (51) between the bearing sleeve (24) and the drive shaft (2).

3. Conveyor unit according to claim 5, characterized in that the bearing sleeve (24) has three step sections (52) with different diameters, with a plain bearing on each of the two outer step sections (52) and at least one sealant on the middle step section (52). (50) is provided.

7. Conveyor unit according to one of the preceding claims, characterized

characterized in that the interacting sections of the drive shaft (2) and the bearing sleeve (24) are conical.

8. Conveyor unit according to one of the preceding claims, characterized

characterized in that the bearing sleeve (24) is made of stainless steel and the

Drive shaft (2), the rotor (4) and the pump stator (3) are made of a plastic, in particular a thermoset.

9. Conveyor unit according to one of the preceding claims, characterized

characterized in that the drive shaft (2) is rotatably mounted

Magnet armature (17) is coupled, which surrounds the drive shaft (2) in a ring and is rotatably mounted on the bearing sleeve (24).

10. Conveyor unit according to one of the preceding claims, characterized

characterized in that the pump stator has an upper layer facing the rotor and a carrier layer facing away from the rotor, the upper layer being made of a thermoset and the carrier layer being made of a thermoplastic.

11. Conveyor unit according to one of the preceding claims, characterized

characterized in that the drive shaft is one facing the bearing sleeve

Upper layer and a carrier layer facing away from the bearing sleeve, the upper layer made of a thermoset and the carrier layer made of a

Thermoplastic is made.