Hydraulic motor with anti-cogging features

Patent metadata

Field	Value
Publication number	US-11493018-B2
Application number	US-202017076902-A
Country	US
Kind code	B2
Filing date	Oct 22, 2020
Priority date	Jan 3, 2020
Publication date	Nov 8, 2022
Grant date	Nov 8, 2022

Abstract

An example hydraulic motor comprises: a stator comprising (i) a stator body having plurality of roller pockets, wherein the stator body comprises a plurality of grooves that are longitudinally-extending, and (ii) a plurality of rollers disposed respectively in the plurality of roller pockets; a rotor having a plurality of external teeth configured to engage with the plurality of rollers of the stator, such that the plurality of rollers and the plurality of external teeth define fluid chambers therebetween configured to expand and contract as the rotor rotates within the stator; and an anti-cogging passage configured to provide pressurized fluid from at least one of the fluid chambers to at least one groove of the plurality of grooves of the stator body, such that pressurized fluid provided to the at least one groove applies a radially-inward force on a respective roller toward the rotor.

First claim

What is claimed is:

1. A hydraulic motor comprising:
a stator comprising (i) a stator body having a central opening and a plurality of roller pockets defined by an interior surface of the stator body, wherein the stator body comprises a plurality of grooves that are longitudinally-extending, and (ii) a plurality of rollers disposed respectively in the plurality of roller pockets, wherein each roller of the plurality of rollers comprises a cylindrical exterior surface;
a rotor disposed within the central opening of the stator body, wherein the rotor comprises a plurality of external teeth configured to engage with the plurality of rollers of the stator, such that the plurality of rollers and the plurality of external teeth define fluid chambers therebetween configured to expand and contract as the rotor rotates within the stator; and
an anti-cogging passage configured to provide pressurized fluid from at least one of the fluid chambers to at least one groove of the plurality of grooves of the stator body, such that pressurized fluid provided to the at least one groove applies a radially-inward force on the cylindrical exterior surface of a respective roller toward the rotor, thereby reducing a likelihood of occurrence of a tip gap between the respective roller and the rotor.

2. The hydraulic motor of claim 1 , wherein the anti-cogging passage is one anti-cogging passage of a plurality of anti-cogging passages, each anti-cogging passage being configured to provide pressurized fluid from a respective fluid chamber of the fluid chambers to a corresponding groove of the plurality of grooves.

3. The hydraulic motor of claim 1 , further comprising:
a manifold interfacing with the stator and the rotor, wherein the manifold comprises a plurality of fluid flow passages configured to communicate pressurized fluid from a source of fluid to the fluid chambers, wherein the anti-cogging passage is disposed in the manifold and fluidly couples a fluid flow passage of the plurality of fluid flow passages of the manifold to the at least one groove of the plurality of grooves of the stator body.

4. The hydraulic motor of claim 1 , further comprising:
a wear plate interfacing with the stator and the rotor, wherein the wear plate comprises a plurality of supply passages configured to respectively receive pressurized fluid from the fluid chambers, wherein the anti-cogging passage is disposed in the wear plate and fluidly couples a supply passage of the plurality of supply passages to the at least one groove of the plurality of grooves.

5. The hydraulic motor of claim 1 , wherein the at least one groove of the plurality of grooves comprises a straight groove and a slot.

6. The hydraulic motor of claim 1 , wherein the at least one groove of the plurality of grooves comprises a semi-circular groove.

7. The hydraulic motor of claim 1 , wherein the stator has a first longitudinal axis, and the rotor comprises a second longitudinal axis parallel to and radially-offset from the first longitudinal axis, and wherein a number of external teeth of the rotor is less than a number of rollers of the plurality of rollers such that the rotor orbits within the stator as the rotor rotates therein.

8. The hydraulic motor of claim 1 , wherein the fluid chambers are separated from one another by an effective moving contact between the external teeth of the rotor and the plurality of rollers, such that a fluid chamber on one side of the effective moving contact receives fluid having a higher pressure level than a respective fluid chamber on other side of the effective moving contact.

9. A rotor set assembly of a hydraulic motor, the rotor set assembly comprising:
a stator comprising (i) a stator body having a central opening and a plurality of roller pockets defined by an interior surface of the stator body, and (ii) a plurality of rollers disposed respectively in the plurality of roller pockets, wherein each roller of the plurality of rollers comprises a cylindrical exterior surface;
a plurality of grooves that are longitudinally-extending and disposed in respective portions of the stator body that bound the plurality of roller pockets; and
a rotor disposed within the central opening of the stator body, wherein the rotor comprises a plurality of external teeth configured to engage with the plurality of rollers of the stator, such that the plurality of rollers and the plurality of external teeth define fluid chambers therebetween configured to expand and contract as the rotor rotates within the stator,
wherein, as the rotor rotates within the stator, at least one groove receives pressurized fluid from a fluid chamber of the fluid chambers, and the pressurized fluid in the at least one groove applies a radially-inward force on the cylindrical exterior surface of a respective roller of the plurality of rollers toward the rotor so as to maintain contact between the respective roller and the rotor and reduce a likelihood of occurrence of a tip gap between the respective roller and the rotor.

10. The rotor set assembly of claim 9 , wherein the at least one groove of the plurality of grooves comprises a straight groove and a slot.

11. The rotor set assembly of claim 9 , wherein the at least one groove of the plurality of grooves comprises a semi-circular groove.

12. The rotor set assembly of claim 9 , wherein the stator has a first longitudinal axis, and the rotor comprises a second longitudinal axis parallel to and radially-offset from the first longitudinal axis, and wherein a number of external teeth of the rotor is less than a number of rollers of the plurality of rollers such that the rotor orbits within the stator as the rotor rotates therein.

13. The rotor set assembly of claim 9 , wherein the fluid chambers are separated from one another by effective moving contact between the external teeth of the rotor and the plurality of rollers, such that a fluid chamber on one side of the effective moving contact receives fluid having a higher pressure level than a respective fluid chamber on other side of the effective moving contact.

14. A hydraulic transmission comprising:
a pump configured to provide pressurized fluid; and
a geroller hydraulic motor fluidly coupled to the pump and configured to receive pressurized fluid therefrom and provide return fluid thereto, wherein the geroller hydraulic motor comprises:
a stator comprising (i) a stator body having a central opening and a plurality of roller pockets defined by an interior surface of the stator body, wherein the stator body comprises a plurality of grooves that are longitudinally-extending and disposed in respective portions of the stator body that bound the plurality of roller pockets, and (ii) a plurality of rollers disposed respectively in the plurality of roller pockets, wherein each roller of the plurality of rollers comprises a cylindrical exterior surface,
a rotor disposed within the central opening of the stator body, wherein the rotor comprises a plurality of external teeth configured to engage with the plurality of rollers of the stator, such that the plurality of rollers and the plurality of external teeth define fluid chambers therebetween, wherein, as the rotor rotates within the stator, a first subset of fluid chambers are configured to expand as the first subset of fluid chambers receive pressurized fluid from the pump, whereas a second subset of fluid chambers are configured to contract as the return fluid exits the second subset of fluid chambers, and
an anti-cogging passage configured to provide pressurized fluid from at least one of the first subset of fluid chambers to at least one groove of the plurality of groov

Assignees

• Parker Hannifin Corp

Inventors

• Merrill Kyle J
• Vacca Andrea
• Manne Venkata Harish Babu
• Pellegri Matteo

Classifications

• F04C2240/20

  Rotors · CPC title

• F04C2/103

  one member having simultaneously a rotational movement about its own axis and an orbital movement · CPC title

• F04C2240/10

  Stators · CPC title

• F04C15/0046

  Internal leakage control · CPC title

• F03C2/08 Primary

  of intermeshing-engagement type, i.e. with engagement of co- operating members similar to that of toothed gearing · CPC title