Energy storage device and work machine

Patent metadata

Field	Value
Publication number	US-12420623-B2
Application number	US-202418607371-A
Country	US
Kind code	B2
Filing date	Mar 15, 2024
Priority date	Mar 16, 2023
Publication date	Sep 23, 2025
Grant date	Sep 23, 2025

Abstract

An exemplary energy storage device is an energy storage device capable of storing energy, which includes a flywheel driven by a motor to store and release rotation energy and a hydraulic element disposed between the motor and the flywheel to change the rotation speed of the flywheel.

First claim

The invention claimed is:

1. An energy storage device capable of storing energy, the energy storage device comprising:
a flywheel that is configured to be driven by a motor to store and release rotation energy; and
a hydraulic element that is disposed between the motor and the flywheel and is configured to change a rotation speed of the flywheel,
wherein the hydraulic element includes a plunger member configured to move in a radial direction perpendicular to an axial direction of the hydraulic element.

2. The energy storage device according to claim 1 , wherein the hydraulic element is a hydromechanical continuously variable transmission.

3. The energy storage device according to claim 1 , further comprising a reducer that is disposed between the hydraulic element and the flywheel.

4. The energy storage device according to claim 3 , wherein the reducer is arranged coaxially with the hydraulic element and the flywheel.

5. The energy storage device according to claim 4 , further comprising a housing that is configured to house the hydraulic element and the reducer.

6. The energy storage device according to claim 1 , further comprising a clutch configured to switch between transmission and interruption of power between the motor and the hydraulic element.

7. The energy storage device according to claim 1 , wherein the plunger member is a sphere.

8. The energy storage device according to claim 1 , wherein the hydraulic element has a hydraulic pump and a hydraulic motor, and the hydraulic pump is a variable displacement hydraulic pump.

9. The energy storage device according to claim 8 , wherein the hydraulic motor is a variable displacement hydraulic motor.

10. The energy storage device according to claim 8 , further comprising a hydraulic servo mechanism configured to control a capacity of the variable displacement hydraulic pump.

11. The energy storage device according to claim 10 , wherein the variable displacement hydraulic pump has:
a ring provided so as to be movable in position by the hydraulic servo mechanism,
a case surrounding an outer periphery of the ring, and
a first oil chamber and a second oil chamber provided between the ring and the case and partitioned from each other.

12. The energy storage device according to claim 11 , wherein the ring has a sealing surface contacting part of the case configured to seal the first oil chamber and the second oil chamber.

13. The energy storage device according to claim 12 , wherein the sealing surface contacting part includes:
an outer peripheral surface of the ring, and
an end surface of the ring in a thickness direction.

14. A work machine comprising:
the energy storage device according to claim 1 ; and
the motor.

15. An energy storage device capable of storing energy, the energy storage device comprising:
a flywheel that is configured to be driven by a motor to store and release rotation energy;
a hydraulic element that is disposed between the motor and the flywheel and is configured to change a rotation speed of the flywheel, wherein the hydraulic element has a hydraulic pump and a hydraulic motor, and the hydraulic pump is a variable displacement hydraulic pump;
a hydraulic servo mechanism configured to control a capacity of the variable displacement hydraulic pump;
wherein the variable displacement hydraulic pump has:
a ring provided so as to be movable in position by the hydraulic servo mechanism,
a case surrounding an outer periphery of the ring, and
a first oil chamber and a second oil chamber provided between the ring and the case and partitioned from each other.

Assignees

• Yanmar Holdings Co Ltd

Inventors

• Ouchida Takeshi

Classifications

• Y02E60/16

  Mechanical energy storage, e.g. flywheels or pressurised fluids · CPC title

• F05B2260/421

  in the form of rotational kinetic energy, e.g. in flywheels · CPC title

• B60W2300/17

  Construction vehicles, e.g. graders, excavators · CPC title

• F16H47/04

  the mechanical gearing being of the type with members having orbital motion · CPC title

• E02F9/2296

  Systems with a variable displacement pump · CPC title