Fluid expansion tank

Patent metadata

Field	Value
Publication number	US-10690152-B1
Application number	US-201715846866-A
Country	US
Kind code	B1
Filing date	Dec 19, 2017
Priority date	Dec 19, 2016
Publication date	Jun 23, 2020
Grant date	Jun 23, 2020

Abstract

An expansion tank includes a tank body mounted inside a housing forming a sump, where the tank body defines an internal expansion volume. A fluid inlet tube on the tank body has an upper end open to the sump and a lower end open to the internal expansion volume. A single 2-way check valve is located at the lower end of the tube, and fluid enters the expansion volume when the pressure in the sump exceeds the pressure in the expansion volume by a first predetermined amount, and fluid exits the expansion volume to the sump when the pressure in the expansion volume exceeds the pressure in the sump by a second predetermined amount. The check valve may be a combination duckbill valve and umbrella valve. The tank body may include a cover on which the inlet tube is formed.

First claim

What is claimed is:

1. An expansion tank for use with a drive device having a housing forming a sump containing hydraulic fluid, the expansion tank comprising:
a tank body disposed in the sump and defining an internal expansion volume;
a fluid inlet tube disposed on the tank body and having a first, upper end open to the sump and a second, lower end open to the internal expansion volume; and
a check valve disposed at the second, lower end of the fluid inlet tube to control fluid flow between the sump and the internal expansion volume, wherein fluid enters the internal expansion volume from the sump when the pressure in the sump exceeds the pressure in the internal expansion volume by a first predetermined amount, and fluid exits the internal expansion volume to the sump when the pressure in the internal expansion volume exceeds the pressure in the sump by a second predetermined amount.

2. The expansion tank of claim 1 , wherein the check valve comprises an umbrella valve that opens to permit fluid to enter the internal expansion volume from the sump when the pressure in the sump exceeds the pressure in the internal expansion volume by the first predetermined amount, and a duckbill valve that opens to permit fluid to exit the internal expansion volume to the sump when the pressure in the internal expansion volume exceeds the pressure in the sump by the second predetermined amount.

3. The expansion tank of claim 1 , wherein the tank body further comprises a main body and a cover, and the check valve is disposed on the cover, and the cover comprises an opening directly adjacent the check valve to permit fluid to flow from the internal expansion volume through the check valve and directly to the sump.

4. The expansion tank of claim 3 , wherein the check valve comprises an umbrella valve that opens to permit fluid to enter the internal expansion volume from the sump when the pressure in the sump exceeds the pressure in the internal expansion volume by the first predetermined amount, and a duckbill valve that opens to permit fluid to exit the internal expansion volume to the sump when the pressure in the internal expansion volume exceeds the pressure in the sump by the second predetermined amount.

5. The expansion tank of claim 4 , wherein the tank body defines an axle opening to accommodate an output axle of the drive device extending through the expansion tank.

6. The expansion tank of claim 1 , wherein the tank body further comprises a main body and a cover, and the check valve is disposed on the cover, wherein the cover is sealed adjacent the check valve, whereby when fluid flows through the check valve to the sump, the fluid first passes through the fluid inlet tube to return to the sump.

7. The expansion tank of claim 6 , wherein the check valve comprises an umbrella valve that opens to permit fluid to enter the internal expansion volume from the sump when the pressure in the sump exceeds the pressure in the internal expansion volume by the first predetermined amount, and a duckbill valve that opens to permit fluid to exit the internal expansion volume to the sump when the pressure in the internal expansion volume exceeds the pressure in the sump by the second predetermined amount.

8. The expansion tank of claim 6 , wherein the main body and the cover define an opening to accommodate an output axle of the drive device extending through the expansion tank.

9. The expansion tank of claim 1 , wherein the tank body further comprises an upwardly extending vent stem in fluid communication with atmospheric pressure.

10. An expansion tank for use with a drive device having a sump containing hydraulic fluid, the expansion tank comprising:
a tank body disposed in the sump and comprising a main body and a cover engaged thereto to define an internal expansion volume;
a fluid inlet tube disposed on the cover and having a first, upper end open to the sump and a second, lower end open to the internal expansion volume;
a combination valve disposed at the second, lower end of the fluid inlet tube to control fluid flow between the sump and the internal expansion volume, the combination valve comprising an umbrella valve that opens to permit fluid to enter the internal expansion volume from the sump when the pressure in the sump exceeds the pressure in the internal expansion volume by a first predetermined amount, and a duckbill valve that opens to permit fluid to exit the internal expansion volume to the sump when the pressure in the internal expansion volume exceeds the pressure in the sump by a second predetermined amount.

11. The expansion tank of claim 10 , wherein the cover further comprises an opening directly adjacent the duckbill valve to permit fluid to flow from the duckbill valve to the sump.

12. The expansion tank of claim 11 , wherein the main body and the cover define an axle opening to accommodate an output axle of the drive device extending through the expansion tank.

13. The expansion tank of claim 11 , wherein the main body further comprises an upwardly extending vent stem in fluid communication with atmospheric pressure and an outwardly extending projection.

14. The expansion tank of claim 10 , wherein the cover is sealed adjacent the combination valve, whereby when fluid flows from the internal expansion volume through the duckbill valve, the fluid first passes through the fluid inlet tube to return to the sump.

15. The expansion tank of claim 14 , wherein the main body and the cover define an opening to accommodate an output axle of the drive device extending through the expansion tank.

16. The expansion tank of claim 14 , wherein the main body further comprises an upwardly extending vent stem in fluid communication with atmospheric pressure.

17. The expansion tank of claim 10 , further comprising an alignment extension to engage a protrusion formed on a housing of the drive device.

18. The expansion tank of claim 10 , further comprising a plurality of stiffening ribs formed on an internal surface of the cover.

19. The expansion tank of claim 10 , further comprising a magnet disposed on the cover.

20. An expansion tank for use with a drive device having a housing forming a sump containing hydraulic fluid, the expansion tank comprising:
a tank body disposed in the sump and defining an internal expansion volume;
a fluid inlet tube disposed on the tank body and having a first, upper end open to the sump and a second, lower end open to the internal expansion volume; and
a combination umbrella valve and duckbill valve disposed at the second, lower end of the fluid inlet tube to control fluid between the sump and the internal expansion volume, wherein fluid enters the internal expansion volume from the fluid inlet tube through the umbrella valve when the pressure in the sump exceeds the pressure in the internal expansion volume by a first predetermined amount, and fluid exits the internal expansion volume through the duckbill valve and directly to the sump when the pressure in the internal expansion volume exceeds the pressure in the sump by a second predetermined amount.

Assignees

• Hydro Gear Lp

Inventors

• Phanco Eric S
• Sparks Bryan K
• Moebs Gregory Barton

Classifications

• F16K17/196

  spring-loaded · CPC title

• F16H61/4096

  with pressure accumulators · CPC title

• F16H39/06

  pump and motor being of the same type · CPC title

• Y10T137/7841

  One valve carries head and seat for second valve · CPC title

• Y10T137/7779

  Axes of ports parallel · CPC title