WO2018041425A1

WO2018041425A1 - Pump device

Info

Publication number: WO2018041425A1
Application number: PCT/EP2017/062033
Authority: WO
Inventors: Markus Braxmaier; Hassan Ghodsi-Khameneh; Daniel Hauer; Mario STAIGER
Original assignee: Ebm-Papst St. Georgen Gmbh & Co. Kg
Priority date: 2016-09-01
Filing date: 2017-05-18
Publication date: 2018-03-08
Also published as: DE212017000110U1; DE102016116384B3

Abstract

A pump device (10) for pumping a liquid has a hydraulic housing (12) in which a pump ring (14) and a cam (18) are accommodated. The cam (18) is connected to a drive (140) via a shaft (20) to allow rotation of the cam (18) via the drive (140) and the shaft (20). The hydraulic housing (12) comprises an annular section (22) with a first connection (51) and a second connection (52), which are fluid-connected to a pump chamber (57) formed between the annular section (22) of the hydraulic housing (12) and a running surface (46) of the pump ring (14). On the inner face of the annular section (22), a bead (55) runs around the opening (53) of the first connection (51) into the pump chamber (57) and around the opening (54) of the second connection (52).

Description

pump device

The invention relates to a pump device for pumping a liquid.

A pump device or pump is understood here to mean a working machine which serves to convey liquids. This also applies

Liquid-solid mixtures, pastes and low-gas liquids. During operation of the pump device, the drive work is converted into the kinetic energy of the transported liquid.

The pumping device shown is also referred to as orbital pump, rotary diaphragm pump or peristaltic pump.

The pump device can be used to direct a liquid from a reservoir, for example a tank, into a desired environment, for example into an exhaust tract of an internal combustion engine.

From document DE 10 2013 104 245 A1 a pump device, which is designed as an orbital pump, is known which has a pump housing with at least one inlet and at least one outlet, wherein on the

Pump housing an eccentric is arranged rotatably relative to the pump housing. To move the eccentric an electric drive is provided. Between the eccentric and the pump housing there is a deformable membrane which, together with the pump housing, delimits a delivery path from the at least one inlet to the at least one outlet and forms at least one seal of the delivery path. In this case, the at least one seal is displaceable by a movement of the eccentric for conveying along the conveying path.

The publication WO 2012/126544 A1 describes a metering system for metering a liquid with a pump device, which via a with an electric motor drivable eccentric drive has. The pump device, which has two directions of delivery, has a pump ring and a stationary ring, which is arranged relative to the pump ring and the eccentric drive so that between the stationary ring and the pump ring, a pump chamber is formed, which changes its shape upon rotation of the electric motor, to pump a liquid to be dispensed through the pump chamber. The document describes the operating principle of an orbital pump.

Against this background, a pump device with the features of claim 1 is presented. Embodiments result from the dependent claims and the description.

There is presented herein a pumping device for pumping a liquid. The pump device has a hydraulic housing in which a pump ring and an eccentric are accommodated, which eccentric is connected via a shaft to a drive to allow rotation of the eccentric via the drive and the shaft, which shaft has an axial direction and a radial direction the pump device defines which hydraulic housing is an annular

Section having a first port and a second port, which are in fluid communication with a pump chamber, which between the

annular portion of the hydraulic housing and a tread of the

Pump ring is formed. On the inner surface of the annular portion around the mouths of the first terminal and the second terminal in the

Pump chamber runs around each bead.

The bead may be formed, for example, by a bulge of the surface of the cylindrical inner surface of the annular portion of the hydraulic housing. The cross-section of the bulge may be symmetrical or asymmetric, ie one flank of the bulge may fall more steeply than the other. In one embodiment, the outer flank of the bead asymptotically transitions into the cylindrical inner surface of the annular portion of the hydraulic housing. The surface of the bead is preferably smooth and continuously curved. In particular, the surface of the bead preferably has no edges, webs, burrs or other local irregularities. In one embodiment, the bead extends completely around the mouth. The bead may extend at a distance from the mouth opening. In one embodiment, the bead runs along the edge of the mouth opening. It can then take on a toroidal shape and partially extend into the mouth opening. In one embodiment, the bead has a height which is smaller than the stroke of the eccentric. The height of the bead is the maximum perpendicular distance of the surface of the bead from the cylindrical inner surface of the annular portion or the difference between the inner radius of the annular portion of the hydraulic housing adjacent the bead and the inner radius of the annular portion of the hydraulic housing at the apex of the bead. For the pump device to effectively convey fluid, the height of the bead must be less than the stroke of the eccentric. In a

Embodiment, the height of the bead is a maximum of 0.1 mm, for example, 0.05 mm. The outer diameter of the bead in the axial direction must be smaller than the width of the tread of the pump ring. The width of the bead can vary. In one embodiment, the width of the bead is none other than half the difference between the width of the tread and the diameter of the mouth of the first or second port. In another embodiment, the width of the bead is a maximum of 0.5 mm, for example from 0.1 to 0.5 mm. The width of the bead is the distance between the outer and inner boundary of the bead.

The on the inner surface of the annular portion of the hydraulic housing around the mouths of the first port and the second port in the

Pump chamber running around beads cause that during operation of the pumping device, the mouth openings of the terminals are kept closed longer and locally around the mouth openings around a higher pressure between the hydraulic housing and the pump ring builds up. This higher pressure promotes the tightness and increases the delivery capacity of the pumping device. Another advantage is that the smooth and rounded contour of the beads damage the tread of the pump ring are avoided when in contact with the mouth openings of the terminals, which increases the life of the pumping device.

In one embodiment, the annular portion of the hydraulic housing is made of plastic. The plastic can be a thermoplastic. In this case, the annular portion of the hydraulic housing are advantageously produced by injection molding. In another embodiment, the annular portion of the hydraulic housing is made of metal, such as aluminum, steel, cast iron or other suitable metallic materials. In another embodiment, the annular portion of the hydraulic housing is made of a ceramic material or a composite material.

In one embodiment, the hydraulic housing further comprises a first lateral portion and a second lateral portion, the annular portion having a first axial side and a second axial side, which first lateral portion on the first axial side and which second lateral portion on the second axial side are arranged, which pump ring is at least partially disposed between the first lateral portion and the second lateral portion, and which second lateral portion as

Drive flange is designed for the drive.

According to one embodiment, the pump device has a clamping member, which is designed to press the pump ring in a clamping member region statically against the annular portion of the pump housing, such a clamping member allows easy sealing of a pump channel in

Clamping member area.

The formation of the second lateral portion as a drive flange allows easy centering and thus a simplified assembly.

According to one embodiment, the second lateral section has a

tubular region, through which tubular region at least partially extends the shaft. Such a tubular portion facilitates the attachment of a part of a drive to the tubular portion, and nevertheless a shaft can be used.

According to one embodiment, the drive comprises a stator assembly, which stator assembly is mounted on the tubular portion of the second lateral portion. As a result, after the alignment of the second lateral section The tubular region and thus also the stator arrangement are likewise aligned on the annular section, and further centering steps can be dispensed with.

According to one embodiment, the second bearing is a rolling bearing with a

Inner ring and an outer ring formed, and the eccentric bears against the inner ring of the second bearing. This allows mounting, in which the shaft is pressed in the eccentric, and possibly also in the second bearing.

According to one embodiment, the second lateral portion has a shoulder, which shoulder is designed to limit a movement of the second bearing in the axial direction to the shoulder, wherein between the shoulder and the second bearing, a sealing ring is provided whose inner diameter is larger than the inner diameter of the second bearing. Such a sealing ring allows the production of the second lateral portion by injection molding, and the second bearing is protected by the sealing ring.

According to one embodiment, the second lateral section has a

tubular portion, and the inner diameter of the sealing ring is smaller than the inner diameter of the tubular portion. This can be at the

Use of an injection molding process for producing the second lateral portion allows a good seal, since the injection mold in the

Area of the shoulder can abut axially against the sealing ring.

According to one embodiment, the first bearing is designed as a movable bearing and the second bearing as a fixed bearing. This training allows easy and safe installation.

According to one embodiment, the eccentric bearing is axially displaceable relative to the eccentric. As a result, the eccentric bearing and thus the pump ring are decoupled from an axial displacement of the shaft, and the pump ring can thus work in the axial direction under defined conditions.

According to one embodiment, the second bearing is designed as a needle bearing. Such a needle bearing allows axial displacement of the eccentric relative to Needle bearings.

According to one embodiment, the eccentric bearing has a smaller axial extent than the eccentric. As a result, the eccentric bearing can move relative to the eccentric in the axial direction, without the eccentric bearing slides down from the eccentric.

In one embodiment, the pump ring is in contact with the first side portion and the second side portion. This allows the formation of pressing forces on the pump ring and thus a good seal.

According to one embodiment, a pump ring carrier is provided in the hydraulic housing.

According to one embodiment, the annular portion of the

Hydraulic housing to a first collar through which the first lateral portion of the hydraulic housing is held in the radial direction of the shaft. On the first collar, the inner surface may be provided, which cooperates with an outer surface of the first lateral portion.

According to one embodiment, the annular portion of the

Hydraulic housing on a second collar through which the second lateral portion of the hydraulic housing is held in the radial direction of the shaft. On the second collar, the inner surface may be provided, which cooperates with an outer surface of the second lateral portion.

Further advantages and embodiments of the invention will become apparent from the

Description and the accompanying drawings.

It is understood that the features mentioned above and those yet to be explained below can be used not only in the respectively specified combination but also in other combinations or alone, without departing from the scope of the present invention. The invention is schematically illustrated by means of embodiments in the drawing and will be described schematically and in detail with reference to the drawing. It shows:

Fig. 1 in a sectional view an embodiment of the described

Pump device

FIG. 2 shows a side view of the pump device of FIG. 1, FIG.

3 is a sectional view of the pump device of Fig. 1,

4 shows an enlarged detail of FIG. 3,

FIG. 5 shows a detail of the annular section of the hydraulic housing of FIG. 1 in the area of the first and second connection in a three-dimensional view; FIG.

Fig. 6 is a diagram of the pressure profile at the mouth of the outlet of the pump chamber of the pump device described.

Fig. 1 shows a sectional view of an embodiment of the presented

Pumping device, which is generally designated by the reference numeral 10 and designed as an orbital pump. The illustration shows a hydraulic housing 12, a pump ring 14, a pump ring carrier 16, an eccentric 18, a shaft 20, a drive 140, a first bearing 1 10, a second bearing 1 18, a bushing 1 12, which also serves as a ring 1 12th can be referred to, a clamping member 1 14, which also as

Separating chamber pin can be designated, an eccentric bearing 1 16, and a sealing ring 120, which can also be referred to as a sealing disc 120.

The first bearing 1 10 is mounted in this embodiment as a floating bearing, and the second bearing 1 18 as a fixed bearing. This results in a good storage.

As eccentric bearing 1 16, a needle bearing can be used. This has a small extent in the radial direction. There are other types of storage as well For example, rolling bearings possible. The eccentric bearing 1 16 allows a low-friction transmission of forces between the rotating eccentric 18 and the rotatably mounted pump ring 14 and pump ring carrier 16th

The hydraulic housing 12 includes an annular portion 22 and a first lateral portion 24, which may also be referred to as a pump cover, and a second lateral portion 26, which also serves as a motor flange or

Drive flange can be designated. The two lateral sections 24, 26 are arranged opposite one another. In this case, the pump ring 14 is at least partially between the two side portions 24, 26 of the hydraulic housing 12. The annular portion 22 has a first collar 74 and a second collar 75th

The drive 140 has a stator assembly 145 and a rotor assembly 146. The driver 140 is partially attached to a tubular portion 170 of the second lateral portion 26.

The pump housing 12 has a locking member 27 which is adapted to lock during insertion of the clamping member 1 14 in the pump housing 12 and the clamping member 1 14 axially secure. The insertion of the clamping member 1 14 can be done prior to assembly of the drive 140.

The pump ring 14 is deformable and may be formed of an elastomeric material or other deformable material.

FIG. 2 shows a side view of the pump device 10 of FIG. 1.

3 shows a cross-section through the pump device 10, as seen along the section line III - III of FIG. 2. A first port 51 and a second port 52 are provided, and these ports 51, 52 are in fluid communication with a pumping chamber 57 between the annular portion 22 of the

Hydraulic housing and a running surface 46 of the pump ring is formed and annular in the illustration of FIG. 3 from the first port 51 in

Clockwise to the second terminal 52 extends. The pump chamber 57 is in Section, which extends from the first port 51 counterclockwise to the second port 52 out through the clamping member 1 14 deactivated by the clamping member 1 14, the tread 46 of the pump ring 14 statically pressed against the annular portion 22 of the hydraulic housing 12 and thereby a fluid flow prevented or at least greatly reduced by this section. The area in which the clamping member 1 14 presses the running surface 46 of the pump ring 14 against the annular portion 22 is also referred to below as clamping member area 45. A bead 55 runs around the mouth 53 of the first port 51 and the mouth 54 of the second port 52. It is also possible for a bead 55 to be provided on only one of the two ports 51, 52. The bead 55 does not have to completely extend around the mouth 53 or 54, but it can also partially run around.

The illustration is shown schematically in the interior of the hydraulic housing 12 and exaggerated with respect to the deformation of the pump ring 14 in order to explain the principle.

The operation of the orbital pump is described below with reference to FIGS. 1 and 3.

The eccentric 18 sits on the shaft 20 and is driven by this. To drive the shaft 20 in turn serves the drive 140, typically a motor or

Electric motor. According to one embodiment, a controllable drive 140 is provided as drive 140.

The shaft 20 is thereby rotated about its longitudinal axis 21, which defines an axial direction of the pump device 10. The eccentric 18 is thus also moved in a rotational movement about the longitudinal axis of the shaft 20. This movement of the eccentric 18 is transmitted via the bearing 1 16 and the pump ring carrier 16 to the pump ring 14. The pump ring carrier 16 and the pump ring 14 are rotationally fixed relative to the hydraulic housing 12, but they are locally moved closer to the annular portion 22 or further depending on the rotational position of the eccentric 18. In Fig. 3, the eccentric 18 in a direction indicated by an arrow 19, in the example shown in the direction 9 o'clock, ie Area of the eccentric 18 with the largest radial extent points in the direction of the arrow 19. This causes the pump ring 14 is moved in this direction 19 and is pressed in the area 58 against the annular portion 22. As a result, the pump channel 57 is reduced in area 58 or completely blocked.

Now, when the eccentric rotates clockwise, the point 58, at which the pump ring 14 is pressed against the annular portion 22, also moves clockwise, and thereby the fluid in the pump chamber 57 in

Clockwise from the first port 51 to the second port 52 pumped or transported. A fluidic short circuit, in which the fluid passes from the second port 52 in a clockwise direction to the first port 51, is prevented by the clamping member 1 14 or other interruption of the pump chamber 57 in this area.

The pump device 10 also works in the reverse direction by the direction of rotation of the eccentric 18 is reversed.

FIG. 4 shows a detail enlargement of the region marked in FIG. 3 by a box around the mouth 54 of the second connection 52 with that around the

In this embodiment, the bead 55 extends along the edge of the mouth opening. She joins her

Inside flank to the mouth opening, their outer edge drops less than the inner edge.

Fig. 5 shows a space-wise representation of a section of the annular

1 in the region of the ports 51 and 52. On the inside of the annular portion 22, a surface 23 is provided which serves to limit a movement of the pump ring 14 to the outside and thereby a deformation of the pump ring 14th to enable. The first connection 51 and the second connection 52 are arranged on the annular portion 22. The connections open out at the openings 53 and 54 into the surface 23. Around the mouth 53 of the first connection 51 and the mouth 54 of the second connection 52 there is a bead in each case 55. The beads 55 each extend completely around the mouth 53 and 54, respectively. The beads 55 run each at the edge of the mouths 53 and 54. The surface of the beads 55 is smooth and has no edges. This will damage the

Pump ring during contact with the beads 55 during operation of the

Pump device avoided. Irregularities of the surface of the beads 55 could also cause the sealing effect of the beads 55 is impaired because the pump ring does not completely close the mouth openings 53 and 54 respectively.

FIG. 6 shows a diagram of the pressure profile at the mouth opening of FIG

Outlet of the pump chamber of the described pump device. Of the

Pressure curve without bead is shown as line 101, and the pressure profile with bead as line 102. When comparing the pressure curve in a pump device without beads with the pressure curve in a pump device according to the invention it is clear that by the beads a higher local pressure around the

Mouth opening is achieved around. In addition, the orifice is sealed over a greater proportion of the pumping cycle. This improves the pumping power and the metering accuracy of the pump device.

Naturally, various modifications and modifications are possible within the scope of the present invention.

Thus, for example, instead of the eccentric 18 and the eccentric bearing 1 16 a combined rolling bearing with concentric inner ring and eccentric outer ring can be used.

The pump device 10 can also be formed without pump ring carrier 16, in which case the pump ring has to be made somewhat stiffer and the pump power becomes lower.

As a second bearing 1 18 may alternatively be used a plain bearing. The pump ring 14 may be formed of an elastomeric material.

Claims

claims

1 . Pumping device (10) for pumping a liquid,

with a hydraulic housing (12), in which a pump ring (14) and a

Eccentric (18) are included,

which eccentric (18) is connected to a drive (140) via a shaft (20) in order to enable rotation of the eccentric (18) via the drive (140) and the shaft (20),

which shaft (20) defines an axial direction (21) and a radial direction of the pump device (10),

which hydraulic housing (12) comprises an annular portion (22), which annular portion (22) has a first port (51) and a second port (52) in fluid communication with a pumping chamber (57) located between the annular portion (22) of the hydraulic housing (12) and a running surface (46) of the pump ring (14) is formed,

wherein on the inner surface (23) of the annular portion (22) around the mouth (53) of the first port (51) into the pump chamber (57) and the mouth (54) of the second port (52) each have a bead (55) runs.

2. Pumping device according to claim 1, wherein the bead (55) itself

extends completely around the mouth (53, 54).

3. Pumping device according to claim 1 or 2, wherein the surface of the bead (55) has no edges.

4. Pumping device according to one of claims 1 to 3, wherein the bead (55) extends at the edge of the mouth.

5. Pumping device according to one of claims 1 to 4, wherein the bead (55) has a height which is smaller than the stroke of the eccentric (18).

6. Pumpenvornchtung according to one of claims 1 to 5, wherein the outer diameter of the bead (55) in the axial direction is smaller than the width of the tread (46) of the pump ring (14).

7. A pump device according to any one of claims 1 to 6, wherein the width of the bead (55) is no more than half the difference of the width of the tread (46) and the diameter of the mouth (53, 54) of the first port (51) or the second port (52) in the pump chamber (57).

8. Pump device according to one of claims 1 to 7, wherein the

annular portion (22) consists of plastic.

9. Pumping device according to claim 8, wherein the plastic a

Thermoplastic is.

10. Pumping device according to claim 9, wherein the annular

Section (22) is made by injection molding.