Hydraulic camshaft adjuster

Patent metadata

Field	Value
Publication number	US-11053820-B2
Application number	US-201916970724-A
Country	US
Kind code	B2
Filing date	Jan 11, 2019
Priority date	Feb 27, 2018
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

The disclosure relates to a hydraulic camshaft adjuster for the variable adjustment of the control times of gas exchange valves of an internal combustion engine, having a stator and a rotor rotatable relative to the stator. Radially inwardly projecting webs are formed on the stator and radially outwardly projecting vanes are formed on the rotor. Between the stator and the rotor are formed several hydraulic working chambers, each of which is divided into a first working chamber and a second working chamber by a vane of the rotor. Two locking elements are inserted into the rotor for the temporary, reversibly detachable fixing of the rotor relative to the stator in a middle position. The first locking element and the second locking element can be locked in a common locking slotted guide. The disclosure also relates to a method for locking of the rotor in such a hydraulic camshaft adjuster.

First claim

The invention claimed is:

1. A hydraulic camshaft adjuster for variable adjustment of control times of gas exchange valves of an internal combustion engine, the hydraulic camshaft adjuster comprising:
a stator having radially inwardly projecting webs;
a rotor having outwardly projecting vanes configured to be rotatable relative to the stator;
a plurality of hydraulic working chambers formed between the stator and the rotor, each of the plurality of hydraulic working chambers divided into working chambers by one of the vanes of the rotor;
a first locking element and a second locking element disposed in the rotor, the first and second locking elements configured to lock the rotor in a middle position relative to the stator; and,
the first locking element and the second locking element configured to be locked in a common stepped locking slotted guide, the stepped locking slotted guide having:
a base, a middle step, and a plateau, the middle step formed between the base and the plateau;
a first stop surface in a first adjustment direction of the rotor and a second stop surface in a second adjustment direction of the rotor are formed on the middle step; and,
a third stop surface in the first adjustment direction of the rotor and a fourth stop surface in the second adjustment direction of the rotor are formed on the base.

2. The hydraulic camshaft adjuster of claim 1 , wherein both the first locking element and the second locking element rest against the base of the stepped locking slotted guide when the rotor is locked in the middle position.

3. The hydraulic camshaft adjuster of claim 1 , wherein the stepped locking slotted guide is formed in a locking cover of the hydraulic camshaft adjuster, the locking cover configured to limit the stator and the rotor in an axial direction.

4. The hydraulic camshaft adjuster of claim 1 , wherein at least one of the first or second locking elements is formed as a stepped locking element.

5. The hydraulic camshaft adjuster of claim 4 , wherein:
the stepped locking element comprises a cylindrical base body with a first diameter and a projection with a second diameter formed coaxially with the cylindrical base body; and,
the first diameter of the cylindrical base body is larger than the second diameter of the projection.

6. The hydraulic camshaft adjuster of claim 5 , wherein a first height of the middle step and a second height of the base are greater than a height of the projection.

7. The hydraulic camshaft adjuster of claim 1 , wherein:
in the first adjustment direction of the rotor, the first locking element is configured to rest against the third stop surface; and,
in the second adjustment direction of the rotor, the second locking element is configured to rest against the stop surface.

8. The hydraulic camshaft adjuster of claim 1 , wherein the first and second locking elements are each supported by a spring arranged within the rotor.

9. The hydraulic camshaft adjuster of claim 3 , wherein the locking cover comprises a first locking cover and a second locking cover.

10. A method for locking the rotor of the hydraulic camshaft adjuster of claim 6 , the method comprising:
providing:
a first stepped locking element with a first cylindrical base body and a first projection; and,
the rotor in a first position so that the first stepped locking element rests on the plateau and the second locking element rests on the base;

moving the rotor in the first adjustment direction to a second position so that the second locking element rests on the base, and a first circumferential bearing surface of the first stepped locking element rests on the plateau, the first circumferential bearing surface formed by a transition area between the first cylindrical base body and the first projection;
moving the rotor in the first adjustment direction to a third position so that the first projection rests on the middle step, and the second locking element rests on the base;
moving the rotor in the first adjustment direction to a fourth position so that the first circumferential bearing surface rests on the middle step, and the second locking element rests on the base; and,
moving the rotor in the first adjustment direction to a fifth position so that the first stepped locking element and the second locking element rest on the base; and, in the second, third, fourth, and fifth positions of the rotor, the rotor is blocked from moving in the second adjustment direction by at least one of the first stepped locking element or the second locking element.

11. The method of claim 10 , wherein:
in the second position of the rotor, the rotor is blocked from moving in the second adjustment direction by the first projection and the second stop surface of the middle step;
in the third position of the rotor, the rotor is blocked from moving in the second adjustment direction by the first cylindrical base body and the second stop surface;
in the fourth position of the rotor, the rotor is blocked from moving in the second adjustment direction by the first projection and the fourth stop surface of the base; and,
in the fifth position of the rotor, the rotor is blocked from moving in the second adjustment direction by the first cylindrical base body and the fourth stop surface.

12. The method of claim 11 , wherein in the fifth position of the rotor, the rotor is blocked from moving in the first adjustment direction by the second locking element.

13. A method for locking a rotor to a stator of a hydraulic camshaft adjuster, comprising:
providing the hydraulic camshaft adjuster, the hydraulic camshaft adjuster having:
a plurality of working chambers formed between outwardly projecting vanes of the rotor and radially inwardly projecting webs of the stator; and,
a first locking element and a second locking element disposed in the rotor, the first and second locking elements configured to lock the rotor in a middle position relative to the stator; and,
the first locking element and the second locking element configured to be locked in a common stepped locking slotted guide, the stepped locking slotted guide having a base, a middle step, and a plateau, the middle step formed between the base and the plateau;

providing the rotor in a first position so that the first and second locking elements rest on the plateau of the stepped locking slotted guide;
moving the rotor in a first adjustment direction to a second position so that the first locking element rests on the middle step of the stepped locking slotted guide;
moving the rotor in the first adjustment direction to a third position so that the first locking element rests on the base;
moving the rotor in the first adjustment direction to a fourth position so that the second locking element rests on the middle step and the first locking element rests on the base;
moving the rotor in the first adjustment direction to a fifth position so that both the first and second locking elements rest on the base; and,
in the second, third, fourth, and fifth positions of the rotor, the rotor is blocked from moving in a second adjustment direction by at least one of the first or second locking elements.

14. The method of claim 13 , wherein:
in the second position of the rotor, the rotor is blocked from moving in the second adjustment direction by the first locking element and a first stop surface of the middle step;
in the third position of the rotor, the rotor is blocked from moving in the second adjustment direction by the first locking element and a second stop surface of the base;
in the fourth position of the rotor, the rotor is blocked from moving in the second adj

Assignees

• Schaeffler Technologies Ag

Inventors

• Keck Michael

Classifications

• F01L2001/34463

  Locking position intermediate between most retarded and most advanced positions · CPC title

• F01L1/3442 Primary

  using hydraulic chambers with variable volume to transmit the rotating force · CPC title

• F01L2250/02

  the camshaft being driven by chains · CPC title

• F01L2001/34466

  with multiple locking devices · CPC title

• F01L2001/34469

  Lock movement parallel to camshaft axis · CPC title