Electromagnet mounting and control system for a variable camshaft phaser containing magneto-rheological fluid

• US 8,096,273 B2
• Filed: 09/24/2009
• Issued: 01/17/2012
• Est. Priority Date: 10/16/2008
• Status: Expired due to Fees

• Current Assignee: Schaeffler Technologies AG & Co.KG (INA-Holding Schaeffler GmbH & Co. KG)
• Original Assignee: Schaeffler Technologies GmbH & Co. KG (INA-Holding Schaeffler GmbH & Co. KG)
• Inventors: Myers, Jesse, Meyer, Roger
• Primary Examiner(s): Denion, Thomas
• Assistant Examiner(s): BERNSTEIN, DANIEL A
• Application Number:
  US12/566,164
• Publication Number:
  US 20100095919A1
• Time in Patent Office: 845 Days
• Field of Search: 123/90.15, 123/90.17, 464/160, 464/161
• US Class Current: 123/90.17
• CPC Class Codes: F01L 1/34 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 Class Codes: F01L 1/3442 using hydraulic chambers with variable volume to transmit the rotating force
• CPC Class Codes: F01L 2001/34483 Phaser return springs
• CPC Class Codes: F01L 2820/00 Details on specific features characterising valve gear arrangements
• CPC Class Codes: F16D 3/10 Couplings with means for varying the angular relationship of two coaxial shafts during motion

Abstract

A magneto-rheological fluid controlled camshaft phaser is provided having a stator with inwardly directed projections which define working spaces therebetween. The stator is adapted to be connected to the crankshaft via a timing gear and chain. A rotor is located radially inside the stator and is connected to the camshaft. Rotor lugs extend radially outwardly from the rotor into the working spaces, dividing them into first and second chambers on each side of the rotor lugs. A magneto-rheological fluid is located in the chambers, and the chambers on each side of each rotor lug are connected via a clearance space between the radially outer surface of the lugs and the inner surface of the stator located between the projections. The rotor is connected to the camshaft. An electromagnetic assembly is mounted adjacent to the stator and includes at least one electromagnet along with at least one ferrous focusing piece. In one embodiment, a plurality of the electromagnets are axially spaced apart from the working chambers holding the magneto-rheological fluid. In another embodiment the electromagnetic is formed by a coil which is radially spaced apart from the working chambers holding the magneto-rheological fluid. In each case, the magnetic field is passed from the electromagnet(s) and the ferrous focusing piece(s) into the phaser via a small air gap spacing between the electromagnet assembly and the moving camshaft phaser.

Claims

1. A magneto-rheological fluid controlled camshaft phaser for controlling a phase angle position of a camshaft, the phaser comprising:

a stator with inwardly directed projections which define working spaces therebetween;

a rotor located radially inside the stator and is adapted to be connected to the camshaft, rotor lugs extend radially outwardly from the rotor into the working spaces, dividing them into first and second chambers on each side of the rotor lugs;

a magneto-rheological fluid located in the chambers, and the chambers on each side of each rotor lug are connected via a clearance space between a radially outer surface of the rotor lugs and an inner surface of the stator located between the projections; and

an electromagnetic assembly mounted adjacent to the stator and including at least one electromagnet along with at least one ferrous focusing piece.

2. The magneto-rheological fluid controlled camshaft phaser of claim 1, wherein the at least one electromagnet comprises a plurality of the electromagnets that are axially spaced apart from the working chambers holding the magneto-rheological fluid.

3. The magneto-rheological fluid controlled camshaft phaser of claim 1, wherein the at least one electromagnet comprises a coil which is radially spaced apart from the working chambers holding the magneto-rheological fluid.

4. The magneto-rheological fluid controlled camshaft phaser of claim 1, wherein a magnetic field is passed from the at least one electromagnet and the at least one ferrous focusing piece into the phaser via a small air gap spacing between the electromagnet assembly and the camshaft phaser.

5. The magneto-rheological fluid controlled camshaft phaser of claim 1, further comprising a trigger wheel and a sensor for determining a camshaft position.

6. The magneto-rheological fluid controlled camshaft phaser of claim 1, wherein the at least one electromagnet comprises a support plate or housing in which the at least one electromagnet is mounted, the support plate or housing being adapted for connection to an internal combustion engine.