Gear systems with variable speed drive

Patent metadata

Field	Value
Publication number	US-12066083-B2
Application number	US-202217977158-A
Country	US
Kind code	B2
Filing date	Oct 31, 2022
Priority date	Apr 16, 2020
Publication date	Aug 20, 2024
Grant date	Aug 20, 2024

Abstract

An epicyclic gear system includes an input sun gear configured to receive rotational input from a turbine of a turbo charger. A first set of planet gears is distributed around and meshes with the input sun gear. A carrier holds the first set of planet gears and defines a rotational axis about which the carrier rotates. A second set of planet gears is mounted to the carrier. An output sun gear is included, wherein the second set of planet gears are distributed around and mesh with the output sun. The output sun gear is configured to deliver rotational power to an internal combustion engine. The carrier is configured to selectively be driven by a variable speed drive to regulate output to the output sun over a range of input rotational speeds of the input sun gear.

First claim

What is claimed is:

1. An epicyclic gear system for an aircraft power plant, the epicyclic gear system comprising:
an input sun gear receiving rotational input and an output sun gear delivering rotational output;
a plurality of planet gears rotatably mounted to a carrier and coupling the input sun gear to the output sun gear, the carrier rotatable about a rotational axis;
a variable speed drive driving the carrier to regulate rotational speed of the carrier to regulate the rotational speed outputted to the output sun gear over a range of input rotational speeds of the input sun gear; and
one or more accessory gears operatively connected to the output sun gear to drive accessory devices.

2. The epicyclical gear system as recited in claim 1 , wherein the plurality of planet gears rotate together about the rotational axis with rotation of the carrier.

3. The epicyclical gear system as recited in claim 1 , wherein the input sun gear is smaller than the output sun gear.

4. The epicyclical gear system as recited in claim 1 , further comprising the variable speed drive connected to drive the carrier with variable speed to regulate output to the output sun over a range of input rotational speeds of the input sun gear.

5. The epicyclical gear system as recited in claim 4 , wherein the variable speed drive is a hydraulic system.

6. An epicyclic gear system for an aircraft power plant, the epicyclic gear system comprising:
an input sun gear receiving rotational input and an output sun gear delivering rotational output;
a plurality of planet gears rotatably mounted to a carrier and coupling the input sun gear to the output sun gear, the carrier rotatable about a rotational axis;
a variable speed drive driving the carrier to regulate rotational speed of the carrier to regulate the rotational speed outputted to the output sun gear over a range of input rotational speeds of the input sun gear, the variable speed drive including an input gear operatively connected to the output sun gear to provide input drive to the variable speed drive.

7. The epicyclical gear system as recited in claim 6 , wherein the input gear is mounted to a bearing having a fixed outer race and an inner race that rotates with the input gear relative to the outer race.

8. The epicyclical gear system as recited in claim 6 , wherein the variable speed drive includes an output gear operatively connected to drive the carrier, wherein the variable speed drive includes an internal mechanism configured to drive the output gear at a different speed from the input gear, and to vary the ratio of speed difference between the input gear and the output gear.

9. The epicyclical gear system as recited in claim 1 , wherein the carrier is mounted to a bearing having a fixed outer race and an inner race that rotates with the carrier relative to the outer race.

10. The epicyclical gear system as recited in claim 1 , wherein the input sun gear and the output sun gear are respectively rotational about a common rotational axis.

11. A method of transmitting rotational power from a rotational input to an rotational output in an aircraft power plant, the method comprising:
receiving the rotational power from the rotational input to an input sun gear of an epicyclic gear system;
driving planet gears of the epicyclic gear system with the input sun gear, wherein the planet gears are operatively connected to a carrier to revolve around the input sun gear;
controlling revolution speed of the carrier with a variable speed drive, including driving the variable speed drive with at least one gear operatively connected to the output sun gear; and
driving an output sun gear of the epicyclic gear system by the planet gears to deliver the rotational power to the rotational output, wherein the rotational power is speed regulated by controlling revolution speed and direction of the carrier and variable speed drive to regulate the output sun gear over a range of input rotational speeds of the input sun gear.

12. The method as recited in claim 11 , further comprising using the variable speed drive itself to vary output speed of the variable speed drive while holding input speed to the variable input drive constant.

13. The method as recited in claim 12 , further comprising varying rotational direction of rotational output of the variable speed drive.

14. The method as recited in claim 12 , wherein controlling revolution speed of the carrier with the variable speed drive includes altering speed of the carrier to maintain constant output speed of the output sun gear given variable input speed to the input sun gear.

Assignees

• Pratt & Whitney Canada

Inventors

• Hodgson Jonathan
• Fric Vlastislav

Classifications

• F16H3/666

  with intermeshing orbital gears (F16H3/663 takes precedence) · CPC title

• F16H2200/2007

  with two sets of orbital gears · CPC title

• B64D35/00

  Transmitting power from power plants to propellers or rotors; Arrangements of transmissions · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F16H15/48

  with members having orbital motion · CPC title