Rocker arm with inboard lost motion spring over valve

Patent metadata

Field	Value
Publication number	US-11549403-B2
Application number	US-202017109666-A
Country	US
Kind code	B2
Filing date	Dec 2, 2020
Priority date	Oct 7, 2016
Publication date	Jan 10, 2023
Grant date	Jan 10, 2023

Abstract

A rocker arm can comprise a first outer arm and a second outer arm joined by a pivot body. An actuatable latch mechanism is within the pivot body. An inner arm assembly comprises a latch arm. A first spring prop is on the inner arm assembly distal from the latch arm. An axle joins the inner arm assembly to pivot between the first outer arm and the second outer arm. A spring is biased against the first outer arm and against the first spring prop. The first spring prop can comprise a hooked end. Or, the first spring prop can extend laterally out from the rocker arm and parallel to the axle. The spring can comprise a one-piece spring comprising first and second coil springs connected by a lateral connector. Or, two separate torsion springs can comprising tangential spring ends extending at approximately 90 degrees.

First claim

What is claimed is:

1. A rocker arm, comprising:
an outer arm assembly comprising:
a pivot body formed at a first end of the rocker arm;
a valve seat formed at a second end of the rocker arm;
a first outer arm and a second outer arm each extending from the pivot body to the second end of the rocker arm, the first outer arm and the second outer arm each including an integrally formed cantilevered post extending laterally outward from a central region of the rocker arm;
a first outer roller and a second outer roller rotatably mounted on the cantilevered post of the first and second outer arms, respectively; and
a first axle arranged at the second end of the rocker arm, the first axle extending from the first outer arm to the second outer arm;

an inner arm assembly arranged within the outer arm assembly between the first outer arm and the second outer arm, the inner arm assembly comprising:
a latch arm arranged to face the pivot body;
a first inner arm and a second inner arm each extending from the latch arm to the first axle such that the inner arm assembly is configured to rotate relative to the outer arm assembly via the first axle;
a second axle extending from the first inner arm to the second inner arm; and
an inner roller rotatably mounted on the second axle;

a latch mechanism arranged in the pivot body, the latch mechanism configured to switch between a latched position in which the latch mechanism extends toward and engages the latch arm, and an unlatched position in which the latch mechanism retracts from the latch arm; and
a lost motion spring disposed around the first axle, the lost motion spring biased against the inner arm assembly and the second end of the rocker arm,
wherein the inner arm assembly is configured to pivot about the first axle independently of the outer arm assembly when the latch mechanism is in the unlatched position.

2. The rocker arm of claim 1 , wherein the inner arm assembly further comprises a spring prop, and wherein the lost motion spring is biased against the inner arm assembly via the spring prop.

3. The rocker arm of claim 2 , wherein the lost motion spring is biased against the second end of the rocker arm via the valve seat.

4. The rocker arm of claim 3 , wherein the valve seat is a valve pallet extending between the first outer arm and the second outer arm.

5. The rocker arm of claim 4 , wherein the valve pallet forms a travel limit for the inner arm assembly.

6. The rocker arm of claim 2 , wherein the spring prop extends from the first inner arm.

7. The rocker arm of claim 2 , wherein the spring prop extends from the first inner arm to the second inner arm.

8. The rocker arm of claim 1 , wherein the latch arm is selectively seated against a latch seat of the latch mechanism when the latch mechanism is in the latched position, and the lost motion spring is configured to bias the latch arm away from the latch seat.

9. The rocker arm of claim 8 , wherein the second axle is mounted to the inner arm assembly between the first axle and the latch arm.

10. The rocker arm of claim 1 , wherein the first axle and the second axle are parallel to each other along a common plane, and a main axis of the latch mechanism extends along the common plane or is angled toward the common plane.

11. A rocker arm, comprising:
an outer arm assembly comprising:
a pivot body formed at a first end of the rocker arm;
a valve pallet formed at a second end of the rocker arm;
a first outer arm and a second outer arm each extending from the pivot body to the second end of the rocker arm, the first outer arm and the second outer arm each including an integrally formed cantilevered post extending laterally outward from a central region of the rocker arm;
a first outer roller and a second outer roller rotatably mounted on the cantilevered post of the first and second outer arms, respectively; and
a first axle arranged at the second end of the rocker arm, the first axle extending from the first outer arm to the second outer arm;

an inner arm assembly arranged within the outer arm assembly between the first outer arm and the second outer arm, the inner arm assembly comprising:
a latch arm arranged to face the pivot body;
a first inner arm and a second inner arm each extending from the latch arm to the first axle such that the inner arm assembly is configured to rotate relative to the outer arm assembly via the first axle;
a spring prop extending from one or both of the first inner arm and the second inner arm;
a second axle extending from the first inner arm to the second inner arm; and
an inner roller rotatably mounted on the second axle;

a latch mechanism arranged in the pivot body, the latch mechanism configured to switch between a latched position in which the latch mechanism extends toward and engages the latch arm, and an unlatched position in which the latch mechanism retracts from the latch arm; and
a lost motion spring around the first axle, the lost motion spring biased against the spring prop and biased against the valve pallet.

12. The rocker arm of claim 11 , wherein the second axle moves independently of the first outer roller and independently of the second outer roller.

13. The rocker arm of claim 11 , wherein the first axle and the second axle are parallel to each other along a common plane, and a main axis of the latch mechanism extends along the common plane or is angled toward the common plane.

14. A rocker arm, comprising:
an outer arm assembly comprising:
a pivot body formed at a first end of the rocker arm;
a valve seat formed at a second end of the rocker arm;
a first outer arm and a second outer arm each extending from the pivot body to the second end of the rocker arm, the first outer arm and the second outer arm each including an integrally formed cantilevered post extending laterally outward from a central region of the rocker arm;
a first outer roller and a second outer roller rotatably mounted on the cantilevered post of the first and second outer arms, respectively; and
a first axle arranged at the second end of the rocker arm, the first axle extending from the first outer arm to the second outer arm;

an inner arm assembly arranged within the outer arm assembly between the first outer arm and the second outer arm, the inner arm assembly comprising:
a latch arm arranged to face the pivot body;
a first inner arm and a second inner arm each extending from the latch arm to the first axle such that the inner arm assembly is configured to rotate relative to the outer arm assembly via the first axle;
a second axle extending from the first inner arm to the second inner arm; and
an inner roller rotatably mounted on the second axle;

a latch mechanism arranged in the pivot body, the latch mechanism configured to switch between a latched position in which the latch mechanism extends toward and engages the latch arm, and an unlatched position in which the latch mechanism retracts from the latch arm; and
a lost motion spring disposed around the first axle, the lost motion spring biased against the inner arm assembly and the second end of the rocker arm,
wherein the first axle and the second axle are parallel to each other along a common plane, and a main axis of the latch mechanism extends along the common plane or is angled toward the common plane.

15. The rocker arm of claim 14 , wherein the valve seat comprises a valve pallet spanning between the first outer arm and the second outer arm on the second end, and wherein the valve pallet is configured to receive a valve stem.

16. The rocker arm of claim 15 , wherein t

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Vance Matthew A

Classifications

• 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

• F01L2001/467

  Lost motion springs · CPC title

• F01L1/2405

  by means of a hydraulic adjusting device located between the cylinder head and rocker arm · CPC title

• F01L1/185 Primary

  Overhead end-pivot rocking arms · CPC title

• F01L1/20

  Adjusting or compensating clearance · CPC title