Pump for conveying a fluid, in particular for conveying an exhaust gas cleaning additive

1. A pump ( 1 ) for delivering a liquid, comprising:

a pump housing ( 2 ) having at least one inlet ( 3 ), at least one outlet ( 4 ), and an inner circumferential face ( 13 ) forming a cylindrical basic form ( 14 );

a drive shaft ( 32 ) defining a geometric axis ( 23 ) and axial direction ( 24 ) of the pump ( 1 );

an eccentric ( 5 ) arranged within the pump housing ( 2 ), the eccentric ( 5 ) being movable relative to the pump housing ( 2 ) about the geometric axis ( 23 ), the eccentric ( 5 ) having an outer face ( 6 );

a deformable element ( 7 ) arranged in a pump gap ( 11 ) between the inner circumferential face ( 13 ) of the pump housing ( 2 ) and the outer face ( 6 ) of the eccentric ( 5 );

a delivery duct ( 8 ) extending from the at least one inlet ( 3 ) to the at least one outlet ( 4 ) by the deformable element ( 7 ) and by the inner circumferential face ( 13 ) of the pump housing ( 2 );

a static seal ( 25 ) arranged between the at least one outlet ( 4 ) and the at least one inlet ( 3 ), the static seal ( 25 ) being configured to prevent a backflow of the liquid from the at least one outlet ( 4 ) back to the at least one inlet ( 3 ); and

centering rings ( 22 ) arranged at both sides of the eccentric ( 5 ), wherein the deformable element ( 7 ) is pressed by the centering rings ( 22 ) against the inner circumferential face ( 13 ) of the pump housing ( 2 ) in each case, such that in each said case one annular contact seal ( 20 ) is formed,

wherein the deformable element ( 7 ) is pressed against the pump housing ( 2 ) along at least one section of the delivery duct ( 8 ) by the outer face ( 6 ) of the eccentric ( 5 ) such that at least one displaceable seal ( 9 ) of the delivery duct ( 8 ) and at least one closed pump volume ( 10 ) are formed in the delivery duct ( 8 ), the at least one displaceable seal ( 9 ) and the at least one closed pump volume ( 10 ) being displaceable along the delivery duct ( 8 ) from the at least one inlet ( 3 ) to the at least one outlet ( 4 ) by an eccentric movement of the eccentric ( 5 ) for the delivery of the liquid, and

wherein the inner circumferential face ( 13 ) of the pump housing ( 2 ) has a recess ( 26 ) in a region of the static seal ( 25 ), and the deformable element ( 7 ) is braced in fluid-tight fashion against the inner circumferential face ( 13 ) in a region of the recess ( 26 ) by a pin ( 27 ), the pin ( 27 ) being configured to fix the centering rings ( 22 ) in the region of the static seal ( 25 ).

2. The pump ( 1 ) according to claim 1 , wherein the pin ( 27 ) is arranged in the recess ( 26 ) such that the pin ( 27 ) is arranged outside the cylindrical basic form ( 14 ).

3. The pump ( 1 ) according to claim 1 , wherein the delivery duct ( 8 ) is formed by the inner circumferential face ( 13 ) and by a concave duct surface of the deformable element ( 7 ), wherein the deformable element ( 7 ) and the inner circumferential face ( 13 ) bear against one another at the annular contact seal ( 20 ) at both sides of the delivery duct ( 8 ) as viewed in the axial direction ( 24 ).

4. The pump ( 1 ) according to claim 3 , wherein the deformable element ( 7 ) has a plurality of radially encircling sealing lips ( 21 ) at the both sides of the delivery duct ( 8 ), which the plurality of radially encircling sealing lips ( 21 ) bear against the inner circumferential face ( 13 ) of the pump housing ( 2 ) and form the annular contact seal ( 20 ).

5. The pump ( 1 ) according to claim 1 , wherein the deformable element has, in the region of the static seal ( 25 ), a plurality of sealing lips ( 21 ) which run parallel to the geometric axis ( 23 ) and which bear against the inner circumferential face ( 13 ) of the pump housing ( 2 ) in the recess ( 26 ) and form the static seal ( 25 ).

6. The pump ( 1 ) according to claim 1 , wherein, with respect to the both sides of the eccentric ( 5 ) in the axial direction ( 24 ) of the pump, the deformable element ( 7 ) is arranged between the inner circumferential face ( 13 ) and the centering rings ( 22 ) arranged at the both sides of the eccentric ( 5 ).

7. The pump ( 1 ) according to claim 6 , wherein the centering rings ( 22 ) arranged at the both sides of the eccentric ( 5 ) have, in the region of the static seal ( 25 ), a protuberance ( 28 ) projecting into the recess ( 26 ) of the inner circumferential face ( 13 ) of the pump housing ( 2 ).

8. A motor vehicle ( 12 ) comprising: an internal combustion engine ( 15 ); and an exhaust gas treatment device ( 16 ) for purification of exhaust gases of the internal combustion engine ( 15 ), the exhaust gas treatment device having a selective catalytic reduction (SCR) catalytic converter ( 17 ) configured to perform the SCR process, wherein the liquid for exhaust gas purification is feedable to the SCR catalytic converter ( 17 ) by the pump ( 1 ) according to claim 1 .

9. A pump ( 1 ) for delivering a liquid, comprising:

a pump housing ( 2 ) having at least one inlet ( 3 ), at least one outlet ( 4 ), and an inner circumferential face ( 13 ) forming a cylindrical basic form ( 14 );

a drive shaft ( 32 ) defining a geometric axis ( 23 ) and axial direction ( 24 ) of the pump ( 1 );

an eccentric ( 5 ) arranged within the pump housing ( 2 ), the eccentric ( 5 ) being movable relative to the pump housing ( 2 ) about the geometric axis ( 23 ), the eccentric ( 5 ) having an outer face ( 6 );

a deformable element ( 7 ) arranged in a pump gap ( 11 ) between the inner circumferential face ( 13 ) of the pump housing ( 2 ) and the outer face ( 6 ) of the eccentric ( 5 );

a delivery duct ( 8 ) extending from the at least one inlet ( 3 ) to the at least one outlet ( 4 ) by the deformable element ( 7 ) and by the inner circumferential face ( 13 ) of the pump housing ( 2 ); and

a static seal ( 25 ) arranged between the at least one outlet ( 4 ) and the at least one inlet ( 3 ), the static seal ( 25 ) being configured to prevent a backflow of the liquid from the at least one outlet ( 4 ) back to the at least one inlet ( 3 ),

wherein the deformable element ( 7 ) is pressed against the pump housing ( 2 ) along at least one section of the delivery duct ( 8 ) by the outer face ( 6 ) of the eccentric ( 5 ) such that at least one displaceable seal ( 9 ) of the delivery duct ( 8 ) and at least one closed pump volume ( 10 ) are formed in the delivery duct ( 8 ), the at least one displaceable seal ( 9 ) and the at least one closed pump volume ( 10 ) being displaceable along the delivery duct ( 8 ) from the at least one inlet ( 3 ) to the at least one outlet ( 4 ) by an eccentric movement of the eccentric ( 5 ) for the delivery of the liquid,

wherein the inner circumferential face ( 13 ) of the pump housing ( 2 ) has a recess ( 26 ) in a region of the static seal ( 25 ), and the deformable element ( 7 ) is braced in fluid-tight fashion against the inner circumferential face ( 13 ) in a region of the recess ( 26 ) by a pin ( 27 ),

wherein, with respect to both sides of the eccentric ( 5 ) in the axial direction ( 24 ), the deformable element ( 7 ) is arranged between the inner circumferential face ( 13 ) and centering rings ( 22 ) arranged at the both sides of the eccentric ( 5 ), wherein the deformable element ( 7 ) is pressed by the centering rings ( 22 ) against the inner circumferential face ( 13 ) of the pump housing ( 2 ) in each case, such that in each said case one annular contact seal ( 21 ) is formed,

wherein the centering rings ( 22 ) arranged at the both sides of the eccentric ( 5 ) have, in the region of the static seal ( 25 ), a protuberance ( 28 ) projecting into the recess ( 26 ) of the inner circumferential face ( 13 ) of the pump housing ( 2 ), and wherein the pin ( 27 ) is configured to fix the centering rings ( 22 ) in the region of the static seal ( 25 ).