Valve assembly having electrical actuator with stepped armature

Patent metadata

Field	Value
Publication number	US-10711754-B2
Application number	US-201715833156-A
Country	US
Kind code	B2
Filing date	Dec 6, 2017
Priority date	Dec 6, 2017
Publication date	Jul 14, 2020
Grant date	Jul 14, 2020

Abstract

A valve assembly for a pump includes an electrical actuator having a stator and an armature, where the armature includes a top armature surface facing the stator and having an inwardly stepped-up profile that forms a raised surface at a radially inward location, and a lower, gap-forming surface at a radially outward location that forms a gap between the armature and the stator when the electrical actuator is activated to facilitate displacing fluid and avoiding production of high velocity, potentially damaging fluid flows.

First claim

What is claimed is:

1. A valve assembly comprising:
a valve member;
an electrical actuator including a stator, and an armature coupled to the valve member;
the armature including an armature plate defining an armature center axis, and being movable between a rest position and an activated position to vary a position of the valve member, in response to a change to an energy state of the electrical actuator;
the armature plate including a top armature surface facing the stator, a bottom armature surface, and an outer perimetric surface extending circumferentially around the armature center axis and axially between the top armature surface and the bottom armature surface; and
the top armature surface having an inwardly stepped-up profile forming a raised surface at a radially inward location that is adjacent to the stator at the activated position, and a lower, gap-forming surface at a radially outward location that forms a gap between the armature and the stator at the activated position, and
further comprising a housing defining a longitudinal housing axis, and the armature center axis is tilted relative to the longitudinal housing axis at the activated position.

2. The valve assembly of claim 1 wherein the valve member extends through the armature plate, and the raised surface and the lower, gap-forming surface each extend circumferentially around an armature pin.

3. The valve assembly of claim 2 wherein each of the raised surface and the lower, gap forming surface is planar, and the lower, gap-forming surface extends radially outward from the raised surface to the outer perimetric surface.

4. The valve assembly of claim 3 wherein the inwardly stepped-up profile is left-right symmetric about the armature center axis.

5. The valve assembly of claim 4 wherein the inwardly stepped-up profile includes a profile of rotation that is circumferentially uniform about the armature center axis.

6. The valve assembly of claim 5 wherein:
the armature plate has a first axial thickness within the raised surface and a second axial thickness within the lower, gap-forming surface, and the first axial thickness is twice the second axial thickness, or less; and
the outer perimetric surface defines a first outer diameter dimension, and the raised surface defines a second outer diameter dimension, and the first outer diameter dimension is twice the second outer diameter dimension, or greater.

7. The valve assembly of claim 1 wherein:
the electrical actuator includes a solenoid actuator having the stator, a winding, and an overmolding encasing the winding;
the stator includes an annular outer stator portion and an annular inner stator portion, and a channel formed radially between the outer stator portion and the inner stator portion, and the winding and overmolding are received within the channel.

8. The valve assembly of claim 7 wherein:
the inner stator portion includes an inner stator end face and the outer stator portion includes an outer stator end face, and the inner stator end face and the outer stator end face are positioned in a common plane; and
the overmolding has an annular slot formed therein that extends inwardly from the common plane, and the gap is in fluid communication with the annular slot at the second position of the armature.

9. A method of operating a valve assembly comprising:
changing an energy state of an electrical actuator of the valve assembly;
moving an armature coupled with a valve member in the valve assembly from a rest position toward a stator in the electrical actuator in response to the change to the energy state of the electrical actuator, the moving of the armature includes tilting a top surface of the armature forming the raised surface and the lower, gap-forming surface relative to the face of the stator;
stopping the moving of the armature at an activated position at which a raised surface at a radially inward location of the armature is adjacent to a face of the stator;
forming a gap at the activated position between a lower, gap-forming surface at a radially outward location of the armature and the face of the stator; and
displacing a fluid from between the armature and the stator by way of the gap.

10. The method of claim 9 wherein the forming of the gap further includes forming the gap in fluid communication with a slot formed in the stator.

11. The method of claim 10 wherein the slot is formed in an overmolding of a solenoid winding of the electrical actuator.

12. The method of claim 11 wherein the displacing of the fluid further includes squeezing the fluid from between the armature and the face of the stator.

13. The method of claim 9 wherein the raised surface has a circular perimeter concentric with a circular perimeter of the lower, gap-forming surface.

14. The method of claim 9 wherein the valve assembly is within a pump, and the moving of the armature further includes moving the armature such that a position of the valve member is varied to vary fluid connections of a pumping chamber in the pump.

15. A valve assembly comprising:
a valve member;
an electrical actuator including a stator, and an armature coupled to the valve member;
the electrical actuator including a solenoid electrical actuator having the stator, a winding, and an overmolding encasing the winding;
the stator includes an annular outer stator portion and an annular inner stator portion, and a channel formed radially between the outer stator portion and the inner stator portion, and the winding and overmolding are received within the channel, the inner stator portion includes an inner stator end face and the outer stator portion includes an outer stator end face, and the inner stator end face and the outer stator end face are positioned in a common plane; and
the overmolding has an annular slot formed therein that extends inwardly from the common plane, and the gap is in fluid communication with the annular slot at the second position of the armature;
the armature including an armature plate defining an armature center axis, and being movable between a rest position and an activated position to vary a position of the valve member, in response to a change to an energy state of the electrical actuator;
the armature plate including a top armature surface facing the stator, a bottom armature surface, and an outer perimetric surface extending circumferentially around the armature center axis and axially between the top armature surface and the bottom armature surface; and
the top armature surface having an inwardly stepped-up profile forming a raised surface at a radially inward location that is adjacent to the stator at the activated position, and a lower, gap-forming surface at a radially outward location that forms a gap between the armature and the stator at the activated position.

Assignees

• Caterpillar Inc

Inventors

• Nelson Bryan Edward
• Mahmood Sana
• Lewis Stephen R

Classifications

• F02M51/0635 Primary

  having a plate-shaped or undulated armature not entering the winding (if entering the winding F02M51/0664) · CPC title

• F02M2200/07

  Fuel-injection apparatus having means for avoiding sticking of valve or armature, e.g. preventing hydraulic or magnetic sticking of parts · CPC title

• F02M59/466

  Electrically operated valves, e.g. using electromagnetic or piezoelectric operating means · CPC title

• F02M59/368

  Pump inlet valves being closed when actuated · CPC title

• F02M63/0075 Primary

  Stop members in valves, e.g. plates or disks limiting the movement of armature, valve or spring · CPC title