Engine accessory drive system

Patent metadata

Field	Value
Publication number	US-2016258409-A1
Application number	US-201514640283-A
Country	US
Kind code	A1
Filing date	Mar 6, 2015
Priority date	Mar 6, 2015
Publication date	Sep 8, 2016
Grant date	—

Abstract

An engine accessory drive (EAD) system for an engine includes a motor-generator (MGU) unit operably coupled to an accessory. The EAD system also includes a gearbox assembly, which includes a first gear train operably coupled to the MGU, and a second gear train operably coupled to an output of the engine. The gearbox assembly also includes a clutch selectively coupling the first gear train with a second gear train. The EAD system further includes a starter assembly, which includes a starter shaft operably coupled to the second gear train. The starter assembly also includes a starter pinion coupled to the starter shaft, and an actuator configured to selectively engage the starter pinion with a flywheel of the engine. Further yet, the EAD system includes an EAD controller configured to selectively operate the EAD system in one of a generator mode, an accessory drive mode, and a starter mode.

First claim

What is claimed is:

1 . An engine accessory drive (EAD) system for an internal combustion engine, the system comprising:
a motor-generator unit (MGU) configured to be operably coupled to an accessory; a gearbox assembly including:
a first gear train operably coupled to the MGU,
a second gear train operably coupled to an output of the engine, and
a clutch selectively coupling the first gear train with a second gear train;
a starter assembly including:
a starter shaft operably coupled to the second gear train,
a starter pinion coupled to the starter shaft, and
an actuator configured to selectively engage the starter pinion with a flywheel of the engine; and
an EAD controller configured to selectively operate the EAD system in one of a generator mode, an accessory drive mode, and a starter mode.

2 . The system of claim 1 , wherein, in the generator mode, the clutch is engaged to couple the first gear train with the second gear train so as to transfer mechanical energy from the output of the engine to the MGU, wherein the MGU is configured to convert the mechanical energy to electrical energy.

3 . The system of claim 2 , wherein, in the accessory drive mode, the clutch is disengaged and the MGU is configured to convert electrical energy to mechanical energy to drive the accessory.

4 . The system of claim 1 , wherein, in the accessory drive mode, the clutch is disengaged and the MGU is configured to convert electrical energy to mechanical energy to drive the accessory.

5 . The system of claim 2 , wherein, in the starter mode, the clutch is disengaged, the actuator is configured to engage the starter pinion with the flywheel, and the MGU is configured to convert electrical energy to mechanical energy to drive the flywheel.

6 . The system of claim 3 , wherein, in the starter mode, the clutch is disengaged, the actuator is configured to engage the starter pinion with the flywheel, and the MGU is configured to convert electrical energy to mechanical energy to drive the flywheel.

7 . The system of claim 4 , wherein, in the starter mode, the clutch is disengaged, the actuator is configured to engage the starter pinion with the flywheel, and the MGU is configured to convert electrical energy to mechanical energy to drive the flywheel.

8 . The system of claim 1 , wherein, in the starter mode, the clutch is disengaged, the actuator is configured to engage the starter pinion with the flywheel, and the MGU is configured to convert electrical energy to mechanical energy to drive the flywheel.

9 . The system of claim 1 , wherein the MGU includes only one input/output shaft to operably couple the MGU to each of the accessory and the gearbox assembly.

10 . The system of claim 1 , wherein the gearbox assembly has a first gear ratio of at least 10:1 to drive the flywheel, and a second gear ratio of at least 2.5:1 to drive the accessory.

11 . The system of claim 1 , wherein the gearbox assembly has a gear ratio of about 14.5:1 to drive the flywheel, and a second gear ratio of about 3:1 to drive the accessory.

12 . The system of claim 1 , wherein the EAD controller is configured to change operation of the EAD system from one of the generator mode, the accessory drive mode, and the starter mode to another of the generator mode, the accessory drive mode, and the starter mode without reducing an operating speed of the MGU to zero.

13 . The system of claim 1 , further comprising an engagement mechanism to selectively decouple the MGU from the first gear train.

14 . The system of claim 1 , wherein the EAD controller is configured to operate the EAD system in the accessory drive mode when the engine is shut off.

15 . The system of claim 1 , further comprising:
an electrical sensor in operative communication with the EAD controller, the electrical sensor configured to measure a state of charge value of a battery system electrically coupled to the MGU, wherein the EAD controller is structured to:
interpret the state of charge value,
change operation of the EAD system from the accessory drive mode to the starter mode when the state of charge value falls below a predetermined value, and
change operation of the EAD system from the starter mode to the generator mode upon the engine starting.

16 . The system of claim 15 , further comprising:
a load sensor in operative communication with the EAD controller, the load sensor configured to measure an accessory load demand value, wherein the EAD controller is structured to:
interpret the accessory load demand value,
determine an MGU output capacity based on the state of charge value,
change operation of the EAD system from the accessory drive mode to the starter mode when the accessory load demand value exceeds the MGU output capacity, and
change operation of the EAD system from the starter mode to the generator mode upon the engine starting.

17 . An engine accessory drive (EAD) system for an internal combustion engine, the system comprising:
a motor-generator unit (MGU) configured to selectively operate as an electric generator and an electric motor, the MGU operably coupled to an energy storage system; a gearbox assembly operably coupled to the MGU and to an output of the engine; an EAD controller in operative communication with each of the MGU and the gearbox assembly, wherein the EAD controller is structured to:
receive engine data indicative of an engine condition,
receive state of charge data indicative of a state of charge of the energy storage system,
interpret each of the engine data and the state of charge data, and
selectively operate the EAD system in one of a generator mode and an accessory drive mode based on the interpreted engine data and state of charge data.

18 . The system of claim 17 , further comprising a starter assembly operably coupled to the gearbox assembly, wherein the EAD controller is further structured to selectively operate the EAD system in a starter mode.

19 . The system of claim 17 , wherein the gearbox assembly is selectable between first and second gear ratios, the first gear ratio being at least four-times higher than the second gear ratio.

20 . The system of claim 19 , wherein the first gear ratio is at least 10:1 and the second gear ratio is at least 2.5:1.

21 . The system of claim 19 , wherein the first gear ratio is about 14:5:1 and the second gear ratio is about 3:1.

22 . The system of claim 19 , wherein the first gear ratio is selected when the EAD system is operational in the starter mode.

23 . The system of claim 19 , wherein the second gear ratio is selected when the EAD system is operational in the accessory drive mode.

24 . The system of claim 19 , wherein the gearbox assembly includes an engagement mechanism to change the gear ratio of the gearbox assembly from one of the first and second gear ratios to the other of the first and second gear ratios without reducing an operating speed of the MGU to zero.

25 . A method, comprising:
providing an engine accessory drive (EAD) controller operably coupled to each of an internal combustion engine and an EAD system, the EAD system including:
a motor-generator unit (MGU) configured to selectively operate as an electric generator and an electric motor,
an energy storage system operably coupled to the MGU, and
a gearbox assembly operably coupled to the MGU and to an output of the engine;
receiving, by the EAD controller, eng

Assignees

• Cummins Inc

Inventors

• Marthaler Michael J
• Rinker Jeffrey W

Classifications

• F02N15/08

  the gearing being of friction type · CPC title

• F02N11/04

  the motors being associated with current generators · CPC title

• F02N15/022

  the starter comprising an intermediate clutch · CPC title

• F02N15/06

  the toothed gears being moved by axial displacement · CPC title

• F02N15/043

  the gearing including a speed reducer · CPC title