Variable belt tensioner for an internal combustion engine

Patent metadata

Field	Value
Publication number	US-9638293-B2
Application number	US-201414530127-A
Country	US
Kind code	B2
Filing date	Oct 31, 2014
Priority date	Oct 31, 2013
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

The present disclosure describes a variable belt tensioner of an internal combustion engine for adjusting a belt tensioning. The tensioner includes in a series configuration an electric motor, a worm drive, a lever drive and a belt tensioner roller. The worm drive is driven by the electric motor and is mechanically connected to the lever drive for transmitting a rotation thereto. The lever drive is mechanically connected to the belt tensioner roller for transmitting a translation thereto, thus allowing the belt tensioner roller to adjust the belt tensioning.

First claim

The invention claimed is:

1. A variable belt tensioner of an internal combustion engine for adjusting a belt tensioning comprising:
an electric motor;
a worm drive driven by the electric motor;
a lever drive mechanically connected to the worm drive for transmitting a rotation thereto, said lever drive comprises a first lever, a second lever and a third lever which are mechanically interconnected, wherein a transmission ratio of the lever drive is derived from the quotient of a first angle (γ) and a second angle (σ), wherein the first angle (γ) is the angle of rotation for the first lever around a first fixed point and the second angle (σ) is the angle of rotation for the third lever around its axis of rotation; and
a belt tensioner roller mechanically connected to the lever drive for transmitting a translation thereto, wherein the belt tensioner roller is positionable to adjust a belt tensioning.

2. The variable belt tensioner according to claim 1 , wherein said first lever rotates around a first pivot point located at a first end of the first lever, and a second end of the first lever moves in a groove formed in the second lever.

3. The variable belt tensioner according to claim 1 , wherein said second lever rotates around a second pivot point and a first end of the second lever is guided through a groove in the third lever.

4. The variable belt tensioner according to claim 1 , wherein said third lever rotates around an axis of rotation corresponding to a first end of said third lever and the belt tensioner roller is rotatably supported on a second end of the third lever.

5. The variable belt tensioner according to claim 1 , wherein the transmission ratio of the lever drive is determined by the lengths of said first, second and third lever.

6. An internal combustion engine comprising a belt which transmits power to a plurality of engine components having a variable belt tensioner according to claim 1 .

7. The variable belt tensioner according to claim 1 further comprising an electronic control unit and a non-transitory computer readable medium having a computer program stored thereon which when executed on the electronic control unit is configured to:
receive an angle of rotation measurement for the first lever around a first pivot from a rotation sensor;
compute an angular deviation based on a sum of a nominal angle and the angle of rotation, wherein the nominal angle is estimated on the basis of a nominal belt force;
determine an actuation current on the basis of the angular deviation; and
apply the actuation current to the electric motor for angularly adjusting the first lever around a first fixed point.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Mueller Torsten
• Sandmann Tobias
• Schlarb Guenther

Classifications

• F16H7/1263 Primary

  where the axis of the pulley moves along a substantially straight path · CPC title

• F16H2007/0823

  Electric actuators · CPC title

• F16H7/1281 Primary

  where the axis of the pulley moves along a substantially circular path · CPC title

• F16H2007/0876

  Control or adjustment of actuators · CPC title

• F16H7/12 Primary

  of an idle pulley · CPC title