Piston accumulator with integrated cylinder rod

Patent metadata

Field	Value
Publication number	US-9964124-B2
Application number	US-201514843293-A
Country	US
Kind code	B2
Filing date	Sep 2, 2015
Priority date	Sep 2, 2015
Publication date	May 8, 2018
Grant date	May 8, 2018

Abstract

A cylinder rod is disposed within a cylinder that defines a cylinder volume. An accumulator defines an accumulator volume that is disposed generally annularly about the cylinder rod. The accumulator volume is separated from the cylinder volume by an accumulator piston.

First claim

What is claimed is:

1. An actuator, comprising:
a rod;
a cylinder housing defining a cylinder volume and an accumulator volume, the cylinder housing movably supporting the rod;
a controllable hydraulic valve, controllable between an open position, in which hydraulic fluid passes through the hydraulic valve between the cylinder volume and a hydraulic system, and a closed position in which the hydraulic fluid is blocked from passing between the cylinder volume and the hydraulic system, wherein the rod is supported for movement outward relative to the cylinder housing in response to fluid under pressure being introduced into the cylinder volume through the hydraulic valve; and
an accumulator piston, movably supported within the cylinder housing and separating the cylinder volume from the accumulator volume in the cylinder housing, wherein the accumulator volume is charged with a compressible medium and wherein the accumulator piston moves to compress the compressible medium in the accumulator volume in response to movement of the rod into cylinder housing when the hydraulic valve is in the closed position so an amount of fluid under pressure in the cylinder volume is constant.

2. The actuator of claim 1 wherein the cylinder housing defines the accumulator volume generally about an outer periphery of the rod.

3. The actuator of claim 2 wherein the cylinder housing comprises:
a guide that has an inner surface and an outer surface and supports the rod for movement along the inner surface.

4. The actuator of claim 3 wherein the guide supports the accumulator piston for movement along the outer surface of the guide.

5. The actuator of claim 4 wherein the cylinder housing defines the accumulator volume generally concentrically about the outer surface of the guide.

6. The actuator of claim 5 and further comprising:
a dampening component mounted within the inner surface of the guide to dampen an accumulator response to movement of the rod inward relative to the cylinder housing with a constant cylinder volume.

7. The actuator of claim 1 wherein the actuator housing comprises a hydraulic actuator housing and wherein the fluid under pressure comprises hydraulic fluid.

8. An actuator, comprising:
a controllable by valve that is in fluid communication with an external hydraulic system and that is controllable to move between an open position and a closed position;
a cylinder housing;
a guide disposed within the cylinder housing, an external surface of the guide and the cylinder housing defining a cylinder volume and an accumulator volume, the cylinder volume being in fluid communication with the external hydraulic system when the controllable hydraulic valve is in the open position and maintain a constant amount of hydraulic fluid when the controllable hydraulic valve is in the closed position;
an accumulator piston, slidably disposed about the guide, within the cylinder housing and separating the cylinder volume from the accumulator volume; and
a rod, supported by an inner surface of the guide, for movement outward relative to the cylinder housing in response to fluid under pressure being introduced through the controllable hydraulic valve into the cylinder volume, wherein the accumulator piston is slidably mounted to reduce the accumulator volume when the rod moves inward relative to the cylinder housing with the controllable hydraulic valve being controlled to be in the closed position to maintain a constant cylinder volume.

9. The actuator of claim 8 wherein the accumulator volume is charged with a compressible medium and wherein the accumulator piston compresses the compressible medium as it reduces the accumulator volume.

10. The actuator of claim 9 and further comprising:
a dampening component mounted within the inner surface of the guide to dampen an accumulator response to movement of the rod inward relative to the cylinder housing with a constant cylinder volume.

11. The actuator of claim 10 wherein the dampening component comprises:
a restrictor that restricts flow of the fluid in the cylinder volume thereacross.

12. A row unit that performs an operation on a crop row, the row unit comprising:
a soil engaging element that engages soil to perform the operation;
a downforce actuator that applies a down force to the soil engaging element, the downforce actuator comprising:
a controllable hydraulic valve,
a rod;
a cylinder housing defining a cylinder volume with a port and an accumulator volume, the controllable hydraulic valve being controllable to move between an open position in which hydraulic fluid can move through the port between the cylinder volume and a hydraulic system and a closed position, in which hydraulic fluid does not move through the port, the cylinder housing movably supporting the rod for movement outward relative to the cylinder housing in response to fluid under pressure being introduced into the cylinder volume through the controllable hydraulic valve and the port; and
an accumulator piston, movably supported within the cylinder housing and separating the cylinder volume from the accumulator volume in the cylinder housing, the accumulator piston compressing a compressible medium in the accumulator volume in response to movement of the rod into the housing with the controllable hydraulic valve controlled to be in the closed position.

13. The row unit of claim 12 wherein the soil engaging element comprises:
an opener that generates a furrow in the soil to receive a seed;
a closer that closes the furrow; and
a set of gauge wheels that control a depth of the furrow and that firm sides of the furrow.

14. The row unit of claim 13 and further comprising:
a gauge wheel load sensor that senses a load on the set of gauge wheels and generates a sensor signal indicative of the sensed load, and wherein a control system receives the sensor signal and controls the fluid under pressure to the downforce actuator based on the sensor signal.

15. The row unit of claim 14 wherein the downforce actuator provides the downforce to a plurality of ganged row units.

16. The row unit of claim 14 wherein the cylinder housing comprises:
a guide that has an inner surface and an outer surface and supports the rod for movement along the inner surface, the guide supporting the accumulator piston for movement along the outer surface.

17. The row unit of claim 16 wherein the cylinder housing defines the accumulator volume generally concentrically about the outer surface of the guide, wherein the accumulator volume is charged with the compressible medium and wherein the accumulator piston moves to compress the compressible medium in the accumulator volume in response to movement of the rod into the cylinder housing with a constant amount of fluid under pressure in the cylinder volume.

18. The row unit of claim 17 wherein the downforce actuator further comprises:
a dampening component mounted within the inner surface of the guide to dampen an accumulator response to movement of the rod inward relative to the cylinder housing with a constant cylinder volume.

Assignees

• Deere & Co

Inventors

• Maro Randall A

Classifications

• F15B15/14

  of the straight-cylinder type · CPC title

• F15B1/24 Primary

  with rigid separating means, e.g. pistons · CPC title

• A01C7/205

  comprising pressure regulation means · CPC title

• A01C5/064

  with rotating tools · CPC title

• F15B2201/31

  having rigid separating means, e.g. pistons · CPC title