Gear machine with eccentricity at the gearwheels

Patent metadata

Field	Value
Publication number	US-9683565-B2
Application number	US-201514699397-A
Country	US
Kind code	B2
Filing date	Apr 29, 2015
Priority date	Apr 29, 2014
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

A gear machine comprises a housing, at least two gearwheels positioned within the housing, and a bearing body defining a circular-cylindrical outer surface segment and a bearing bore. The at least two gearwheels configured to mesh in external engagement with each other. At least one of the gearwheels includes at least one bearing journal rotatably positioned within the bearing bore. The bearing body is positioned within the housing with the circular-cylindrical outer surface segment engaging a corresponding bearing surface defined on the inside of the housing. Each of the at least two gearwheels includes a plurality of tooth tips configured to engage a corresponding sealing surface defined on the inside of the housing. At least one segment of at least one of the sealing surface and the bearing bore is eccentric with respect to the circular-cylindrical outer surface segment of the bearing body. A method of production is also provided.

First claim

What is claimed is:

1. A gear machine, comprising:
a housing;
at least two gearwheels positioned within the housing, the at least two gearwheels configured to mesh in external engagement with each other; and
a bearing body defining a circular-cylindrical outer surface segment and a bearing bore;
wherein:
at least one of the at least two gearwheels includes at least one bearing journal rotatably positioned within the bearing bore;
the bearing body is positioned within the housing with the circular-cylindrical outer surface segment engaging a corresponding bearing surface defined on the inside of the housing;
each of the at least two gearwheels includes a plurality of tooth tips configured to engage a corresponding sealing surface defined on the inside of the housing;
at least one segment of at least one of the sealing surface and the bearing bore is eccentric with respect to the circular-cylindrical outer surface segment of the bearing body; and
the sealing surface includes a first segment that is flush with the bearing surface and a second segment having a circular-cylindrical shape arranged eccentrically with respect to the bearing surface.

2. The gear machine according to claim 1 , wherein:
the at least two gearwheels comprises a first gear wheel and a second gearwheel;
the first gear wheel is configured to engage a first sealing surface defined on the inside of the housing;
the second gear wheel is configured to engage a second sealing surface defined on the inside of the housing, the second sealing surface configured similar to the first sealing surface to include a first segment and a second segment; and
the second segment of the first sealing surface has at least one of a different diameter and a different eccentricity than the second segment of the second sealing surface.

3. The gear machine according to claim 1 , wherein an entire circumference of the bearing bore has a circular-cylindrical shape that is eccentric with respect to the circular-cylindrical outer surface segment of the bearing body.

4. The gear machine according to claim 3 , wherein an eccentricity of the bearing bore with respect to the circular-cylindrical outer surface segment of the bearing body is configured such that an axis of rotation of the at least one of the at least two gearwheels is centric with respect to a corresponding bearing surface during the operation of the gear machine.

5. The gear machine according to claim 1 , wherein a selected direction of the eccentricity is parallel to a direction of a force that a pressurized fluid is configured to exert on a respective gearwheel during operation.

6. The gear machine according to claim 5 , wherein:
the at least two gearwheels comprises a first gear wheel and a second gearwheel that are each positioned symmetrically in relation to a plane of symmetry; and
the direction of the eccentricity is at an angle of between 15° and 45° with respect to the plane of symmetry.

7. The gear machine of claim 6 , wherein the direction of the eccentricity is at an angle of 30°.

8. The gear machine of claim 1 , wherein the gear machine is configured as a gear pump.

9. The gear machine of claim 1 , wherein the gear machine is configured as a gear motor.

10. A method for producing a gear machine that includes (i) a housing, (ii) at least two gearwheels positioned within the housing, the at least two gearwheels configured to mesh in external engagement with each other, (iii) a bearing body defining a circular-cylindrical outer surface segment and a bearing bore, wherein (a) at least one of the at least two gearwheels includes at least one bearing journal rotatably positioned within the bearing bore, (b) the bearing body is positioned within the housing with the circular-cylindrical outer surface segment engaging a corresponding bearing surface defined on the inside of the housing, (c) each of the at least two gearwheels includes a plurality of tooth tips configured to engage a corresponding sealing surface defined on the inside of the housing, and (d) at least one segment of at least one of the sealing surface and the bearing bore is eccentric with respect to the circular-cylindrical outer surface segment of the bearing body, the method comprising performing a run-in operation including the steps of:
(i) filling the gear machine with pressurized fluid;
(ii) running the gear machine at a predetermined operating pressure of the pressurized fluid; and
(iii) selecting an eccentricity such that material of the sealing surface is removed by at least one of the at least two gearwheels.

11. The method according to claim 10 , further comprising:
forming the bearing bore in the bearing body;
after forming the bearing bore, forming the circular-cylindrical outer surface segment of the bearing body; and
while the circular-cylindrical outer surface segment is formed, mounting the bearing body on a mandrel that engages in the bearing bore.

12. The method according to claim 11 , further comprising:
during the production of the circular-cylindrical outer surface segment, clamping the bearing body against the mandrel in a direction of a force which the pressurized fluid exerts on the at least two gearwheels during the operation of the gear machine.

13. A gear machine, comprising:
a housing;
at least two gearwheels positioned within the housing, the at least two gearwheels configured to mesh in external engagement with each other; and
a bearing body defining a circular-cylindrical outer surface segment and a bearing bore;
wherein:
at least one of the at least two gearwheels includes at least one bearing journal rotatably positioned within the bearing bore;
the bearing body is positioned within the housing with the circular-cylindrical outer surface segment engaging a corresponding bearing surface defined on the inside of the housing;
each of the at least two gearwheels includes a plurality of tooth tips configured to engage a corresponding sealing surface defined on the inside of the housing;
at least one segment of at least one of the sealing surface and the bearing bore is eccentric with respect to the circular-cylindrical outer surface segment of the bearing body;
a selected direction of the eccentricity is parallel to a direction of a force that a pressurized fluid is configured to exert on a respective gearwheel during operation;
the at least two gearwheels comprises a first gear wheel and a second gearwheel that are each positioned symmetrically in relation to a plane of symmetry; and
the direction of the eccentricity is at an angle of 30° with respect to the plane of symmetry.

14. The gear machine according to claim 13 , wherein:
the first gear wheel is configured to engage a first sealing surface defined on the inside of the housing;
the second gear wheel is configured to engage a second sealing surface defined on the inside of the housing, the second sealing surface configured similar to the first sealing surface to include a first segment and a second segment; and
the second segment of the first sealing surface has at least one of a different diameter and a different eccentricity than the second segment of the second sealing surface.

15. The gear machine according to claim 13 , wherein an entire circumference of the bearing bore has a circular-cylindrical shape that is eccentric with respect to the circular-cylindrical outer surface segment of the bearing body.

16. The gear machine according to claim 15 , wherein an eccentricity of the bearing bore with respect to the circular-cylindrical outer surface segment of the bearing body is configured

Assignees

• Bosch Gmbh Robert

Inventors

• Bredenfeld Guido
• Stahl Markus
• Cholewa Christoph

Classifications

• F04C15/0026

  Elements specially adapted for sealing of the lateral faces of intermeshing-engagement type machines or pumps, e.g. gear machines or pumps · CPC title

• F04C2230/602

  Gap; Clearance · CPC title

• F04C18/082

  Details specially related to intermeshing engagement type pumps · CPC title

• F04C2/086 Primary

  Carter · CPC title

• F04C2/18

  with similar tooth forms (F04C2/16 takes precedence) · CPC title