Drive train

Patent metadata

Field	Value
Publication number	US-10738752-B2
Application number	US-201615778031-A
Country	US
Kind code	B2
Filing date	Nov 22, 2016
Priority date	Dec 2, 2015
Publication date	Aug 11, 2020
Grant date	Aug 11, 2020

Abstract

A drive train for a motor vehicle includes an internal combustion engine, a starting device, and a vibration isolation device. The internal combustion engine has a main order of vibration and an excitation frequency predetermined by a predetermined operating principle and a predetermined number of cylinders. The starting device is for starting the internal combustion engine and has an electric machine with a torque characteristic over a speed (n). The vibration isolation device is designed for the main order of vibration of the internal combustion engine. The vibration isolation device has a resonance characteristic below an idling speed (nL) of the internal combustion engine in a resonance range occurring in a first speed range (Δn 2 ). The resonance range is shifted into a second, lower speed range (Δn 1 ) when the electric machine is coupled. The electric machine is arranged to supply a torque effective beyond the second, lower speed range (Δn 1 ).

First claim

The invention claimed is:

1. A drive train for a motor vehicle comprising:
an internal combustion engine which operates according to a predetermined operating principle, the internal combustion engine comprising:
a crankshaft;
a predetermined number of cylinders; and,

a main order of vibration predetermined by the predetermined operating principle at the predetermined number of cylinders, the main order of vibration comprising an excitation frequency;
a starting device, arranged downstream of the crankshaft for starting the internal combustion engine by rotating the crankshaft in a speed range of the excitation frequency, the starting device comprising an electric machine with a torque characteristic over a speed (n);
a vibration isolation device, arranged downstream of the crankshaft, designed for the main order of vibration of the internal combustion engine, wherein:
the vibration isolation device comprises a resonance characteristic below an idling speed (nL) of the internal combustion engine in a resonance range occurring in a first speed range (Δn 2 );
the resonance range is shifted into a second, lower speed range (Δn 1 ) when the electric machine is coupled; and,
the electric machine is arranged to supply a torque effective beyond the second, lower speed range (Δn 1 ); and

a device for power supply to the electric machine to compensate a falling voltage when the internal combustion engine is started.

2. The drive train of claim 1 , wherein the starting device is a damping device in the second, lower speed range (Δn 1 ).

3. The drive train of claim 1 , wherein:
the predetermined operating principle is a four stroke principle; and,
during starting of the internal combustion engine, the predetermined number of cylinders is fewer than four.

4. The drive train of claim 1 , wherein the electric machine is connected for conjoint rotation with the crankshaft, at least until the first speed range (Δn 2 ) has been traversed.

5. The drive train of claim 4 , wherein a flow of current from the electric machine into a power supply device of the electric machine is prevented.

6. The drive train of claim 5 , wherein:
the starting device comprises a first electric motor and a second electric motor with respective motor constants;
the first electric motor motor constant is different than the second electric motor motor constant; and,
the first electric motor and the second electric motor are connected in parallel.

7. The drive train of claim 4 , wherein a flow of current from the electric machine into a power supply device of the electric machine is prevented.

8. The drive train of claim 7 , wherein:
the starting device comprises a first electric motor and a second electric motor with respective motor constants;
the first electric motor motor constant is different than the second electric motor motor constant; and,
the first electric motor and the second electric motor are connected in parallel.

9. A drive train for a motor vehicle comprising:
an internal combustion engine which operates according to a predetermined operating principle, the internal combustion engine comprising:
a crankshaft;
a predetermined number of cylinders; and,
a main order of vibration predetermined by the predetermined operating principle and the predetermined number of cylinders, the main order of vibration comprising an excitation frequency;

a starting device, arranged downstream of the crankshaft, for starting the internal combustion engine by rotating the crankshaft in a speed range of the excitation frequency, the starting device comprising an electric machine with a torque characteristic over a speed (n); and,
a vibration isolation device, arranged downstream of the crankshaft, designed for the main order of vibration of the internal combustion engine, wherein:
the vibration isolation device comprises a resonance characteristic below an idling speed (nL) of the internal combustion engine in a resonance range occurring in a first speed range (Δn 2 );
the resonance range is shifted into a second, lower speed range (Δn 1 ) when the electric machine is coupled;
the electric machine is arranged to supply a torque effective beyond the second, lower speed range (Δn 1 );
the electric machine is designed as a series-wound motor; and,
the electric machine remains in rotational engagement with the crankshaft beyond the first speed range (Δn 2 ).

10. The drive train of claim 9 , wherein the starting device is a damping device in the second, lower speed range (Δn 1 ).

11. The drive train of claim 9 , wherein:
the predetermined operating principle is a four stroke principle; and,
during starting of the internal combustion engine, the predetermined number of cylinders is fewer than four.

12. The drive train of claim 9 , wherein a flow of current from the electric machine into a power supply device of the electric machine is prevented.

13. The drive train of claim 12 , wherein:
the starting device comprises a first electric motor and a second electric motor with respective motor constants;
the first electric motor motor constant is different than the second electric motor motor constant; and,
the first electric motor and the second electric motor are connected in parallel.

14. The drive train of claim 13 , wherein the starting device is a damping device in the second, lower speed range (Δn 1 ).

15. A drive train for a motor vehicle comprising:
an internal combustion engine which operates according to a predetermined operating principle, the internal combustion engine comprising:
a crankshaft;
a predetermined number of cylinders; and,
a main order of vibration predetermined by the predetermined operating principle and the predetermined number of cylinders, the main order of vibration comprising an excitation frequency;

a starting device, arranged downstream of the crankshaft, for starting the internal combustion engine by rotating the crankshaft in a speed range of the excitation frequency, the starting device comprising an electric machine with a torque characteristic over a speed (n); and,
a vibration isolation device, arranged downstream of the crankshaft, designed for the main order of vibration of the internal combustion engine, wherein;
the vibration isolation device comprises a resonance characteristic below an idling speed (nL) of the internal combustion engine in a resonance range occurring in a first speed range (Δn 2 );
the resonance range is shifted into a second, lower speed range (Δn 1 ) when the electric machine is coupled;
the electric machine is arranged to supply a torque effective beyond the second, lower speed range (Δn 1 ); and
a motor constant of the electric machine can be modified by a field weakening device.

16. The drive train of claim 15 , wherein the electric machine is selected from the group consisting of:
a DC motor;
a three-phrase synchronous motor with a frequency converter; and,
a three-phrase asynchronous motor with a variable frequency drive.

17. The drive train of claim 15 , wherein:
the predetermined operating principle is a four stroke principle; and,
during starting of the internal combustion engine, the predetermined number of cylinders is fewer than four.

18. The drive train of claim 15 , wherein the electric machine is connected for conjoint rotation with the crankshaft, at least until the first speed range (Δn 2 ) has been traversed.

Assignees

• Schaeffler Technologies Ag

Inventors

• Grethel Marco
• Baehr Markus
• Choi Hyung Wook

Classifications

• F02N2300/104

  Control of the starter motor torque · CPC title

• B60W30/20

  Reducing vibrations in the driveline · CPC title

• H02P9/008

  wherein the generator is controlled by the requirements of the prime mover · CPC title

• F02D2400/02

  Four-stroke combustion engines with electronic control · CPC title

• F02N2200/022

  Engine speed · CPC title