Camshaft adjuster and method for operating a camshaft adjuster

Patent metadata

Field	Value
Publication number	US-9920660-B2
Application number	US-201415112597-A
Country	US
Kind code	B2
Filing date	Dec 9, 2014
Priority date	Feb 5, 2014
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A method for operating a camshaft adjuster, which includes an adjusting transmission with an input shaft, an output shaft connected in a non-rotatable manner with a camshaft, and an adjusting shaft, whereby the adjusting shaft is driven by an actuator, characterized by the fact that the actuator drives the adjusting shaft by overcoming a torque that is dependent on its angular position.

First claim

What is claimed is:

1. A camshaft adjuster, comprising:
an adjusting transmission, comprising:
an input shaft;
a camshaft; and,
an output shaft non-rotatably connected to said camshaft; and,

an adjusting shaft, wherein an actuator drives said adjusting shaft by overcoming a torque that is dependent on an angular position of said adjusting shaft.

2. The camshaft adjuster as recited in claim 1 , wherein said torque transmitted by said actuator to said adjusting shaft fluctuates periodically, whereby a cycle of fluctuations of said torque extends for less than half a revolution of said adjusting shaft.

3. The camshaft adjuster as recited in claim 2 , wherein for a full revolution of said adjusting shaft of the adjusting transmission when load-free, said torque acting between said actuator and said adjusting shaft goes through at least two minima and maxima.

4. The camshaft adjuster as recited in claim 1 , wherein during an adjustment said torque has an alternating sign and acts in a same direction between said actuator and said adjusting shaft.

5. The camshaft adjuster as recited in claim 1 , wherein a difference between a maximum torque acting between said actuator and said adjusting shaft and a minimum torque acting between said actuator and said adjusting shaft corresponds to at least 20% of an average torque acting between said actuator and said adjusting shaft.

6. A camshaft adjuster, comprising:
an adjusting transmission, comprising,
an input shaft;
a camshaft; and,
an output shaft non-rotatably connected to said camshaft;

an adjusting shaft, wherein a plurality of positions of said output shaft allow said output shaft to be adjustable with a torque that is incremental in a first direction and a second direction; and,
an actuator operatively arranged to transfer an angle-dependent variable torque to said adjusting shaft.

7. The camshaft adjuster as recited in claim 6 , wherein said adjusting transmission is a shaft transmission.

8. The camshaft adjuster as recited in claim 7 , wherein said adjusting transmission further comprises a rolling bearing with an even number of rolling elements.

9. The camshaft adjuster as recited in claim 8 , wherein said rolling bearing of said adjusting transmission has a varying geometrical design along a respective circumference.

10. The camshaft adjuster as recited in claim 6 , wherein said plurality of positions of said output shaft are locking positions in which said output shaft remains without torque from said actuator.

Assignees

• Schaeffler Technologies Ag

Inventors

• Kohrs Mike
• SCHäFER JENS
• Hildebrand Marco

Classifications

• F01L2250/02

  the camshaft being driven by chains · CPC title

• F01L1/047

  Camshafts · CPC title

• F01L1/34 Primary

  characterised by the provision of means for changing the timing of the valves without changing the duration of opening {and without affecting the magnitude of the valve lift} · CPC title

• F01L2001/0473

  Composite camshafts, e.g. with cams or cam sleeve being able to move relative to the inner camshaft or a cam adjusting rod · CPC title

• F01L2250/04

  the camshaft being driven by belts · CPC title