Belt drive system for an internal combustion engine

Patent metadata

Field	Value
Publication number	US-10018254-B2
Application number	US-201615167266-A
Country	US
Kind code	B2
Filing date	May 27, 2016
Priority date	May 27, 2016
Publication date	Jul 10, 2018
Grant date	Jul 10, 2018

Abstract

A belt drive system for rotatably coupling an internal combustion engine to an electric machine is described. The belt drive system includes a serpentine belt and a hydraulic strut tensioner, wherein the hydraulic strut tensioner is disposed to exert a tension force on the serpentine belt. A controller is operatively connected to the electric machine and includes an instruction set that is executable to periodically induce a reduction in torque output of the electric machine.

First claim

The invention claimed is:

1. A belt drive system for an internal combustion engine rotatably coupled to an electric machine, comprising:
a serpentine belt disposed in a belt run that includes a first pulley coupled to the internal combustion engine and a second pulley coupled to the electric machine, and a hydraulic strut tensioner disposed to exert a tension force on the serpentine belt; and
a controller operatively connected to the electric machine, wherein the controller includes an instruction set, the instruction set being executable to periodically induce a reduction in torque output of the electric machine.

2. The belt drive system of claim 1 , wherein the instruction set is executable to periodically induce the reduction in torque output of the electric machine when the electric machine is operating in a torque generating state.

3. The belt drive system of claim 2 , wherein the instruction set is executable to periodically induce the reduction in the torque output of the electric machine when the electric machine is operating in the torque generating state for an extended period of time.

4. The belt drive system of claim 1 , wherein the hydraulic strut tensioner comprises a linear tensioning device including a compression coil spring arranged in parallel with a hydraulic damping cylinder; and
wherein the reduction in the torque output of the electric machine includes a pulsed reduction in the torque output having a magnitude and a time period that are determined based upon a spring constant of the compression coil spring.

5. The belt drive system of claim 4 , wherein the magnitude and time period of the pulsed reduction in the commanded motor torque are indirectly related to the spring constant of the compression coil spring.

6. The belt drive system of claim 1 , wherein the hydraulic strut tensioner comprises a linear tensioning device including a compression coil spring arranged in parallel with a hydraulic damping cylinder; and
wherein a repetition rate of the periodically induced reduction in torque output of the electric machine is determined based upon a spring constant of the compression coil spring and a damping coefficient of the hydraulic damping cylinder.

7. An internal combustion engine, comprising:
a belt drive system disposed to rotatably couple a crankshaft of the internal combustion engine and an electric machine, wherein the belt drive system includes a serpentine belt and a hydraulic strut tensioner, wherein the hydraulic strut tensioner is disposed to exert a force on the serpentine belt; and
a controller operatively connected to the electric machine, wherein the controller includes an instruction set, the instruction set being executable to periodically induce a reduction in torque output of the electric machine when the electric machine is operating in a torque generating state.

8. The internal combustion engine of claim 7 , wherein the instruction set is executable to periodically induce the reduction in the torque output of the electric machine when the electric machine is operating in the torque generating state for an extended period of time.

9. The internal combustion engine of claim 7 , wherein the hydraulic strut tensioner comprises a linear tensioning device including a compression coil spring arranged in parallel with a hydraulic damping cylinder; and
wherein the reduction in the torque output of the electric machine includes a pulsed reduction in the torque output having a magnitude and a time period that are determined based upon a spring constant of the compression coil spring.

10. The internal combustion engine of claim 9 , wherein the magnitude and time period of the pulsed reduction in the commanded motor torque are indirectly related to the spring constant of the compression coil spring.

11. The internal combustion engine of claim 7 , wherein the hydraulic strut tensioner comprises a linear tensioning device including a compression coil spring arranged in parallel with a hydraulic damping cylinder; and
wherein a repetition rate of the periodically induced reduction in torque output of the electric machine is determined based upon a spring constant of the compression coil spring and a damping coefficient of the hydraulic damping cylinder.

12. A method for controlling operation of an electric machine that is rotatably coupled to an internal combustion engine via a belt drive system, wherein the belt drive system includes a hydraulic strut tensioner, the method comprising:
operating the electric machine in a torque generating state; and
periodically inducing, via a controller, a pulsed reduction in a commanded torque output from the electric machine when the electric machine operates in the torque generating state for an extended period of time.

13. The method of claim 12 , comprising periodically inducing the reduction in torque output of the electric machine when the electric machine is operating in a torque generating state.

14. The method of claim 13 , comprising periodically inducing the reduction in the torque output of the electric machine when the electric machine is operating in the torque generating state for an extended period of time.

15. The method of claim 12 , wherein the hydraulic strut tensioner comprises a linear tensioning device including a compression coil spring arranged in parallel with a hydraulic damping cylinder; and
wherein periodically inducing the pulsed reduction in the commanded torque output of the electric machine includes inducing a pulsed reduction in the torque output having a magnitude and a time period that are determined based upon a spring constant of the compression coil spring.

16. The method of claim 15 , wherein the magnitude and time period of the pulsed reduction in the commanded motor torque are indirectly related to the spring constant of the compression coil spring.

17. The method of claim 12 , wherein the hydraulic strut tensioner comprises a linear tensioning device including a compression coil spring arranged in parallel with a hydraulic damping cylinder; and
wherein a repetition rate of the periodically induced reduction in torque output of the electric machine is determined based upon a spring constant of the compression coil spring and a damping coefficient of the hydraulic damping cylinder.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Wright Mark W
• Checkles Constantine R
• Cottrell V Daniel D

Classifications

• F16H7/0829 Primary

  with vibration damping means · CPC title

• F16H2007/0806

  Compression coil springs · CPC title

• F16H2007/0812

  Fluid pressure · CPC title

• F02B63/04

  for electric generators · CPC title

• F16H7/02 Primary

  with belts; with V-belts · CPC title