Hydraulic system

Patent metadata

Field	Value
Publication number	US-10677249-B2
Application number	US-201515538470-A
Country	US
Kind code	B2
Filing date	Dec 16, 2015
Priority date	Dec 22, 2014
Publication date	Jun 9, 2020
Grant date	Jun 9, 2020

Abstract

A hydraulic system includes a circulation pump assembly (2) provided with a speed controller (4, 26), a hydraulic circuit (A, B) connected to the circulation pump assembly (2) as well as a mechanical switch device (86, 88; 120, 122; 120″, 122″) which is subjected to pressure from a fluid in the hydraulic circuit (A, B) and which can be moved into at least two different switch positions. The mechanical switch device (28; 86, 28; 120, 122) can be moved by the circulation pump assembly (2) by way of a hydraulic coupling via the fluid. The speed controller is configured to initiate a movement of the switch device (86, 88; 120, 122; 120″, 122″) by way of at least one hydraulic force acting thereon and causing a movement of the switch device (86, 88; 120, 122; 120″, 122″), produced via the hydraulic circuit, via a speed adaptation of the circulation pump assembly.

First claim

The invention claimed is:

1. A hydraulic system comprising:
at least one circulation pump assembly provided with a speed controller;
at least one hydraulic circuit connected to the circulation pump assembly;
at least one mechanical switch device which is subjected to pressure from a fluid in the hydraulic circuit and which can be moved into at least two different switch positions, wherein the at least one mechanical switch device can be moved by the circulation pump assembly by way of a hydraulic coupling via the fluid, and the speed controller is configured to initiate a movement of the switch device by way of at least one hydraulic force acting upon the switch device and causing a movement of the switch device which is produced via the hydraulic circuit via a speed adaptation of the circulation pump assembly, wherein the mechanical switch device is configured to react to differences in a course of a pressure build-up of the fluid given a speed change of the circulation pump assembly, such that the switch device moves into a first switch position given a speed change of the circulation pump assembly with a first course of the pressure build-up, and into a second switch position given a speed change of the circulation pump assembly with a second course of the pressure build-up which is different to the first course.

2. A hydraulic system according to claim 1 , wherein the mechanical switch device is configured to react to pressure changes due to the speed change of the circulation pump assembly, such that the mechanical switch device can be selectively moved into one of the switch positions in dependence on the pressure or a change of the pressure, wherein the mechanical switch device comprises a first movable valve element and a second movable valve element, the first movable valve element being arranged in a first of the hydraulic circuits and the second movable valve element being arranged in a second of the hydraulic circuits, the first movable valve element being connected to a first spring, the second movable valve element being connected to a second spring, the first spring comprising a first spring compression rate, the second spring comprising a second spring compression rate, the first spring compression rate being different from the second spring compression rate.

3. A hydraulic system according to claim 1 , wherein the mechanical switch device is configured in self-holding manner, to remain in an assumed switch position up to a predefined speed or speed change of the circulation pump assembly.

4. A hydraulic system according to claim 1 , wherein the speed controller is configured such that at least two different speed courses of the circulation pump assembly can be set by the speed controller, wherein the speed controller is configured such that the circulation pump assembly permits speed changes with at least two different acceleration courses.

5. A hydraulic system according to claim 1 , wherein the switch device is configured such that movements into the at least two different switch positions are effected with different temporal delays, wherein the movements are effected along differently long paths and/or counter to differently large damping, inertia forces and/or biasing forces.

6. A hydraulic system according to claim 1 , further comprising at least another hydraulic circuit to provide at least two hydraulic circuits wherein the circulation pump assembly is connected to the at least two hydraulic circuits, and the mechanical switch device is subjected to fluid pressure via at least one of the hydraulic circuits, such that the switch device is movable by way of the forces produced by the fluid pressure.

7. A hydraulic system according to claim 1 , further comprising at least another hydraulic circuit to provide at least two hydraulic circuits wherein the circulation pump assembly is connected to the at least two hydraulic circuits and the at least one mechanical switch device is configured as at least one valve with at least one movable valve element for a change of a ratio of flows through the at least two hydraulic circuits and for switching-over a flow path between the at least two hydraulic circuits.

8. A hydraulic system according to claim 6 , wherein the switch device comprises at least one first control surface, upon which a fluid pressure in a first of the hydraulic circuits, a fluid pressure at the exit of the first hydraulic circuit acts, and at least one second control surface, upon which a fluid pressure in a second of the hydraulic circuits or at the delivery side of the circulation pump assembly acts.

9. A hydraulic system according to claim 8 , wherein the control surfaces are connected to the at least one valve element such that a fluid pressure acting upon the control surfaces effects at least one force which acts upon the valve element and which is directed at least partly in the direction of a movement axis of the valve element.

10. A hydraulic system according to claim 8 , wherein the first control surface is larger than the second control surface.

11. A hydraulic system according to claim 8 , wherein the first and the second control surface are arranged such that the forces which are produced by the fluid pressure on the first and the second control surface at least partly are directed counter to one another.

12. A hydraulic system according to claim 8 , wherein the first and the second control surface, in the hydraulic system are placed and dimensioned such that given a speed change of the circulation pump assembly, a pressure build-up on the first control surface is effected more slowly than on the second control surface, wherein with a first more rapid speed change, the more rapid pressure increase at the second control surface effects a movement of the switch device, whereas with a second relatively slower speed change, a pressure build-up on the first and second control surface is effected so slowly that a force equilibrium of the forces acting upon the control surfaces is maintained.

13. A hydraulic system according to claim 1 , wherein the switch device is additionally subjected to gravity force, to a magnet force and/or spring force, and these forces act in the direction of a movement axis of the switch device.

14. A hydraulic system according to claim 8 , wherein the switch device is additionally subjected to gravity force, to a magnet force and/or spring force, and these forces act in the direction of a movement axis of the switch device and the gravity force, magnet force and/or spring force are directed at least partly counter to a force acting upon the second control surface by the fluid pressure.

15. A hydraulic system according to claim 8 , wherein the at least one valve elements is configured as a movable hollow cylinder, wherein a first axial end of the hollow cylinder forms an entry opening which can be connected to the second hydraulic circuit, and the hollow cylinder in a peripheral wall comprises at least one second entry opening which is connectable to the first hydraulic circuit, and a second axial end of the hollow cylinder forms an exit opening which is connected to an entry of the circulation pump assembly.

16. A hydraulic system according to claim 15 , wherein the second axial end of the hollow cylinder is in connection with a suction port of an impeller of the circulation pump assembly.

17. A hydraulic system according to claim 8 , where the at least one valve element is configured as a movable hollow cylinder, with a first axial end forming an entry opening which can be connected to the second hydraulic circuit and a peripheral wal

Assignees

• Grundfos Holding As

Inventors

• Blad Thomas
• Blad Christian

Classifications

• F04D15/0066

  by changing the speed, e.g. of the driving engine · CPC title

• F16K11/0708

  comprising means to avoid jamming of the slide or means to modify the flow · CPC title

• F24D19/1012

  by regulating the speed of a pump · CPC title

• Y02B30/745

  Cross-Sectional Technologies · mapped topic

• F04D15/0005

  by using valves · CPC title