Vortex diffuser for rotating/stationary interfaces

Patent metadata

Field	Value
Publication number	US-9836066-B2
Application number	US-201414333324-A
Country	US
Kind code	B2
Filing date	Jul 16, 2014
Priority date	Jul 16, 2014
Publication date	Dec 5, 2017
Grant date	Dec 5, 2017

Abstract

In hydraulic systems having rotating-stationary component interfaces, a bore pressure regulating mechanism is provided to interact with the hydraulic fluid in a control volume to maintain a hydraulic fluid pressure in a longitudinal shaft bore at or approximately equal to a supply pressure when a gear shaft rotates within the control volume. In one aspect, the bore pressure regulating mechanism minimizes vortex flow of the hydraulic fluid induced by the rotation of the gear shaft. In another aspect, the bore pressure regulating mechanism provides a direct feed of pressurized hydraulic fluid proximate an opening of the longitudinal shaft bore through an end surface of the gear shaft, and thereby minimizes the opportunity for the hydraulic fluid to be forced into vortex flow by the gear shaft in the area of the longitudinal shaft bore.

First claim

What is claimed is:

1. A component interface for a rotating shaft and a stationary housing of a transmission, comprising:
a housing having a housing bore defining a bore longitudinal axis, and a fluid supply passage intersecting the housing bore;
a cylindrical shaft aligned along the bore longitudinal axis, the cylindrical shaft having a longitudinal shaft bore extending through the cylindrical shaft from an opening through a shaft end surface of the cylindrical shaft, wherein a shaft end portion of the cylindrical shaft is received by the housing bore and rotatably supported therein, wherein the housing bore and the shaft end portion define a control volume and the fluid supply passage places the control volume in fluid communication with a pressurized hydraulic fluid source for supplying pressurized hydraulic fluid having a supply pressure; and
a bore pressure control mechanism disposed within the control volume and interacting with the pressurized hydraulic fluid within the control volume to maintain a shaft bore pressure at the opening of the longitudinal shaft bore approximately equal to the supply pressure when the cylindrical shaft rotates about the bore longitudinal axis.

2. The component interface according to claim 1 , wherein the bore pressure control mechanism comprises a baffle disposed within the control volume and engaged by the housing, wherein the baffle engages the pressurized hydraulic fluid to reduce vortex flow of the pressurized hydraulic fluid about the bore longitudinal axis when the cylindrical shaft rotates.

3. The component interface according to claim 2 , wherein the housing includes a cap having a cap inner surface and being attached to an open end of the housing bore, wherein the baffle comprises a first baffle extending inwardly from the cap inner surface toward the shaft end surface, and a second baffle extending inwardly from the cap inner surface toward the shaft end surface and being spaced from the first baffle to define a gap there between that is substantially axially aligned with the longitudinal shaft bore when the cap is attached to the housing wall.

4. The component interface according to claim 3 , including a third baffle extending inwardly from the cap inner surface toward the shaft end surface, wherein the first baffle, the second baffle and the third baffle are circumferentially spaced about the bore longitudinal axis and are spaced from each other to define a gap there between that is substantially axially aligned with the longitudinal shaft bore when the cap is attached to the housing wall.

5. The rotating-stationary component interface according to claim 2 , wherein the baffle comprises an elongated baffle having a baffle length that is greater than a housing bore inner diameter, and wherein the housing bore includes a first bore recess and a second bore recess formed in diametrically opposed sides of the housing bore, with each of the first bore recess and the second bore recess receiving a corresponding elongated baffle end.

6. The rotating-stationary component interface according to claim 5 , wherein the elongated baffle comprises a recessed notch in a baffle end surface facing the shaft end surface, with the recessed notch being axially aligned with the longitudinal shaft bore.

7. The rotating-stationary component interface according to claim 2 , wherein the baffle comprises a first baffle leg, a second baffle leg and a third baffle leg each extending from a central hub and being circumferentially spaced from each other, and wherein the housing bore includes a first bore recess, a second bore recess and a third bore recess formed in the housing bore and being circumferentially spaced from each other, with each of the first bore recess, the second bore recess and the third bore recess receiving a baffle leg end of a corresponding one of the first baffle leg, the second baffle leg and the third baffle leg.

8. The rotating-stationary component interface according to claim 2 , wherein the housing wall comprises a cap having a cap inner surface and being attached to an open end of the housing bore, wherein the baffle comprises a cylindrical baffle portion extending inwardly from the cap inner surface toward the shaft end surface, the cylindrical baffle portion having a feed passage there through placing a baffle portion outer surface in fluid communication with a baffle portion end surface facing the opening of the longitudinal shaft bore.

9. The rotating-stationary component interface according to claim 2 , wherein the housing wall comprises a cap having a cap inner surface and being attached to an open end of the housing bore, wherein the baffle comprises a cylindrical baffle portion extending inwardly from the cap inner surface toward the shaft end surface, the removable cap and the cylindrical baffle portion having a throughbore there through axially aligned with the longitudinal shaft bore, and wherein the bore pressure control mechanism further comprises a fluid conduit placing a throughbore opening in an outer surface of the removable cap in fluid communication with the pressurized hydraulic fluid source.

10. A bore pressure control mechanism for a component interface of a rotating shaft and a stationary housing of a transmission comprising:
a housing having a housing bore with a bore longitudinal axis, a fluid supply passage intersecting the housing bore, and a cylindrical shaft aligned along the bore longitudinal axis, the cylindrical shaft having a longitudinal shaft bore extending through the cylindrical shaft from an opening through a shaft end surface, wherein a shaft end portion of the cylindrical shaft is received by the housing bore and rotatably supported therein, and wherein the housing wall and the shaft end portion define a control volume and the fluid supply passage places the control volume in fluid communication with a pressurized hydraulic fluid source for supplying pressurized hydraulic fluid having a supply pressure, the bore pressure control mechanism; and
a baffle disposed within the control volume and engaged by the housing wall, wherein the baffle engages the pressurized hydraulic fluid to reduce vortex flow of the pressurized hydraulic fluid about the bore longitudinal axis when the cylindrical shaft rotates about the bore longitudinal axis to maintain a shaft bore pressure at the opening of the longitudinal shaft bore approximately equal to the supply pressure when the cylindrical shaft rotates.

11. The bore pressure control mechanism according to claim 10 , wherein the baffle comprises a first baffle formed with and extending inwardly from the housing bore end wall toward the shaft end surface, and a second baffle formed with and extending inwardly from a housing bore end wall toward the shaft end surface and being spaced from the first baffle to define a gap there between that is substantially axially aligned with the longitudinal shaft bore.

12. The bore pressure control mechanism according to claim including, a third baffle formed with and extending inwardly from the housing bore end wall toward the shaft end surface, wherein the first baffle, the second baffle and the third baffle are circumferentially spaced about the bore longitudinal axis and are spaced from each other to define a gap there between that is substantially axially aligned with the longitudinal shaft bore.

13. The bore pressure control mechanism according to claim 10 , wherein the baffle comprises an elongated baffle having a baffle length that is greater than a housing bore inner diameter, and wherein the housing bore includes a first bore recess and a second bore recess formed in diametrically opposed sides of the housing bore

Assignees

• Caterpillar Inc

Inventors

• Williams Brian James
• Batdorff Mark Allen
• Lorentz Timothy
• Steffen Jay Robert

Classifications

• F15D1/00 Primary

  Influencing flow of fluids · CPC title

• F15B21/006

  Compensation or avoidance of ambient pressure variation · CPC title

• G05D7/0186 Primary

  without moving parts · CPC title

• F16H2061/0046

  Details of fluid supply channels, e.g. within shafts, for supplying friction devices or transmission actuators with control fluid · CPC title