Disengageable speed-reducing unit

Patent metadata

Field	Value
Publication number	US-11028781-B2
Application number	US-201816607225-A
Country	US
Kind code	B2
Filing date	May 2, 2018
Priority date	May 4, 2017
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A speed-reducing unit, particularly for transferring torque between a gas turbine and a fan in a turbine engine, includes an annular ring, at least one gear that is coupled to the ring, the ring including two annular half-rings that are offset relative to each other along the main axis of the speed-reducing unit and that are coupled with at least one gear, and a plate for supporting the two half-rings, in relation to which the two half-rings are rotationally fixed about the main axis of the speed-reducing unit. Each half-ring includes an internal helical tooth. Each half-ring is connected to the support plate so as to be able to be uncoupled from at least one gear when at least one gear exerts a disengaging action on each half-ring, with the amplitude of the action being greater than a determined amplitude value.

First claim

The invention claimed is:

1. A speed reducer, comprising:
an annular ring gear coaxial to a main axis of the speed reducer and having radially inner teeth,
at least one gear which is coupled with the ring gear and which includes radially outer teeth complementary to the teeth of the annular ring gear,
wherein the ring gear includes two annular half-ring gears offset with respect to each other along the main axis of the speed reducer and which are coupled with said at least one gear, and a support plate for supporting both half-ring gears, with respect to which both half-ring gears are rotatably immovable about the main axis of the speed reducer, each half-ring gear including helical inner teeth tilted in a direction opposite to the tilt direction of the teeth of the other half-ring gear,
wherein each half-ring gear is connected to the support plate so as to be able to be uncoupled from said at least one gear when said at least one gear exerts on each half-ring gear an unclutching action the amplitude of which is higher than a determined amplitude value,
wherein each half-ring gear is slidably mounted with respect to the support plate, along a direction parallel to the main axis of the speed reducer, between a coupled position in which said half-ring gear is coupled with said at least one gear and an uncoupled position in which said half-ring gear is uncoupled from said at least one gear, and
wherein the speed reducer includes retaining means, for retaining said half-ring gear in its coupled position, said retaining means, being able to be disengaged to enable said half-ring gear to be moved to the uncoupled position when said at least one gear exerts on each half-ring gear said unclutching action.

2. The speed reducer according to claim 1 , wherein the retaining means include at least one abutting member associated with each half-ring gear, which axially abuts against an abutting face of the half-ring gear associated therewith, and which is able to change state when said at least one gear exerts on the half-ring gear said unclutching action.

3. The speed reducer according to claim 2 , wherein the abutting member includes a deformable stop ring associated with each half-ring gear, which abuts against said abutting face of the half-ring gear associated therewith and which is carried by a rod oriented parallel to the main axis of the speed reducer and which passes through an axial port made in both half-ring gears.

4. The speed reducer according to claim 3 , wherein the retaining means include a thrust bearing member associated with each half-ring gear, which is able to cooperate with the associated half-ring gear when it is in its uncoupled position, and
wherein the thrust bearing member includes a washer received in an associated groove formed in one end of the rod associated with said half-ring gear.

5. The speed reducer according to claim 2 , wherein the abutting member includes a fusible thrust bearing which is able to be ruptured when said at least one gear exerts on the half-ring gear said action.

6. The speed reducer according to claim 5 , wherein the fusible thrust bearing includes an attachment portion for attaching the fusible thrust bearing to the support plate and an abutting portion for abutting the fusible thrust bearing against said abutting face of the half-ring gear.

7. The speed reducer according to claim 5 ,
wherein the retaining means include a thrust bearing member associated with each half-ring gear, which is able to cooperate with the associated half-ring gear when it is in its uncoupled position, and
wherein the thrust bearing member includes at least one ball thrust bearing arranged in a spline of the support plate, which is able to cooperate with the associated half-ring gear when it is in one of the uncoupled position and the coupled position.

8. The speed reducer according to claim 1 , wherein the retaining means include a thrust bearing member associated with each half-ring gear, which is able to cooperate with the associated half-ring gear when it is in its uncoupled position.

9. The speed reducer according to claim 1 , wherein each half-ring gear is movably driven to its uncoupled position through the axial force resulting from the action of said at least one gear on the helical teeth of the half-ring gear.

10. The speed reducer according to claim 9 , further comprising driving means for movably driving each half-ring gear to its uncoupled position.

11. The speed reducer according to claim 10 , wherein said driving means include a compression spring which is axially compressed between both half-ring gears.

12. The speed reducer according to claim 1 , comprising a planetary gearset type reducer and wherein said ring gear is the outer annular ring gear of the gearset and said at least one gear includes a plurality of planet gears connected to each other by a planet carrier.

13. An aircraft turbomachine comprising:
a low pressure turbine, a low pressure shaft which is coupled with the low pressure turbine and a fan which is coupled with the low pressure shaft, and the speed reducer according to claim 1 , through which the fan is coupled with the low pressure shaft.

14. The speed reducer according to claim 1 , wherein the speed reducer is configured to transmit torque between a gas turbine and a fan in a turbomachine.

Assignees

• Safran Trans Systems

Inventors

• Beck Guillaume Julien
• Morelli Boris Pierre Marcel

Classifications

• F16H55/17

  Toothed wheels (worm wheels F16H55/22; chain wheels F16H55/30) · CPC title

• F16H57/08 Primary

  of gearings with members having orbital motion · CPC title

• F05D2220/36

  specially adapted for the fan of turbofan engines · CPC title

• F02C7/36 Primary

  Power transmission arrangements between the different shafts of the gas turbine plant, or between the gas-turbine plant and the power user ({F02C3/107 - F02C3/13 and} F02C7/32 take precedence; couplings for transmitting rotation F16D; gearing in general F16H) · CPC title

• F16H2055/176

  Ring gears with inner teeth · CPC title