Mechanical fuel pump deactivation

Patent metadata

Field	Value
Publication number	US-10273945-B2
Application number	US-201414448176-A
Country	US
Kind code	B2
Filing date	Jul 31, 2014
Priority date	Jul 31, 2014
Publication date	Apr 30, 2019
Grant date	Apr 30, 2019

Abstract

A mechanical fuel pump is disclosed for delivering fuel to an engine of a vehicle, the mechanical fuel pump having an activated configuration and a deactivated configuration. A dual fuel system and method are also disclosed for use with the mechanical fuel pump.

First claim

What is claimed is:

1. A fuel pump comprising:
a rotatable camshaft including a lobe which protrudes from the camshaft and is immovable relative to the camshaft as the camshaft rotates through a plurality of revolutions;
a pump housing defining a pump chamber;
a pump piston mounted in the pump chamber for reciprocal movement; and
a deactivating element operatively positioned between the lobe and the pump piston, the deactivating element having:
a first configuration wherein the deactivating element transfers movement of the lobe to the pump piston to deliver fuel to an engine; and
a second configuration wherein the deactivating element absorbs movement of the lobe, thereby causing the pump piston to remain substantially stationary and avoid operating the fuel pump during rotation of the camshaft through the plurality of revolutions.

2. The fuel pump of claim 1 , wherein the deactivating element is rigid in the first configuration and collapsible in the second configuration.

3. The fuel pump of claim 1 , wherein the deactivating element comprises:
an outer body;
an inner body; and
at least one locking pin being movable between:
a locked position corresponding to the first configuration, wherein the inner body moves with the outer body in the locked position; and
an unlocked position corresponding to the second configuration, wherein the inner body moves relative to the outer body in the unlocked position.

4. The fuel pump of claim 3 , wherein, in the unlocked position of the at least one locking pin, at least one spring forces the at least one locking pin radially inward and away from the outer body.

5. The fuel pump of claim 3 , wherein the at least one locking pin is biased in the unlocked position.

6. The fuel pump of claim 3 , wherein, in the locked position of the at least one locking pin, a pressurized fluid in the inner body forces the at least one locking pin radially outward and toward the outer body.

7. The fuel pump of claim 3 , wherein the pump piston moves along a first axis and the at least one locking pin moves along a second axis transverse to the first axis.

8. The fuel pump of claim 1 , further comprising a lobe follower coupled to the deactivating element to interact with the lobe of the rotatable camshaft.

9. A fuel pump comprising:
a rotatable camshaft including a lobe which protrudes from the camshaft and is immovable relative to the camshaft as the camshaft rotates through a plurality of revolutions;
a pump housing defining a pump chamber;
a pump piston reciprocally mounted in the pump chamber; and
a deactivating element that uncouples the lobe from the pump piston to cause the pump piston to remain substantially stationary and avoid operating the fuel pump during rotation of the camshaft through the plurality of revolutions.

Assignees

• Cummins Inc

Inventors

• Cecil Adam C

Classifications

• F04B27/0437

  Disconnecting the pistons from the actuated cam · CPC title

• F02M59/102

  Mechanical drive, e.g. tappets or cams (F02M45/063 takes precedence) · CPC title

• F04B9/042

  the means being cams · CPC title

• F01L13/0036

  the valves being driven by two or more cams with different shape, size or timing or a single cam profiled in axial and radial direction · CPC title

• F01L1/08

  Shape of cams · CPC title