Starter/generator for an internal combustion engine, especially an engine of a motor vehicle

• US 6,177,734 B1
• Filed: 02/27/1998
• Issued: 01/23/2001
• Est. Priority Date: 02/27/1998
• Status: Expired due to Term

• Current Assignee: Andreas Grundl, Bernhard Hoffmann, Thomas Pels
• Original Assignee: Grundl und Hoffman GmbH, Isad Electronic Systems GmbH & Co. KG
• Inventors: Gründl, Andreas, Zeyen, Klaus-Peter, Hoffmann, Bernhard, Pels, Thomas, Masberg, Ullrich
• Primary Examiner(s): Ponomarenko, Nick
• Application Number:
  US09/032,323
• Time in Patent Office: 1,061 Days
• Field of Search: 290/31, 290/32, 290/34, 290/36.R, 290/47, 290/40.C
• US Class Current: 290/31
• CPC Class Codes: B60K 2001/003 with means for cooling the electrical propulsion units
• CPC Class Codes: B60K 2006/262 the motor or generator are used as clutch, e.g. between engine and driveshaft
• CPC Class Codes: B60K 2006/268 Electric drive motor starts the engine, i.e. used as starter motor
• CPC Class Codes: B60K 28/16 responsive to, or preventing, skidding of wheels brake control systems for vehicle drive stability B60T8/1755; arrangements responsive to a speed condition for adjusting wheel braking force B60T8/32; control of vehicle driving stability otherwise than by controlling the propulsion unit only B60W30/02; preventing wheel slippage by reducing power in rail vehicles B61C15/00
• CPC Class Codes: B60K 6/26 characterised by the motors or the generators
• CPC Class Codes: B60K 6/387 Actuated clutches, i.e. clutches engaged or disengaged by electric, hydraulic or mechanical actuating means
• CPC Class Codes: B60K 6/485 Motor-assist type
• CPC Class Codes: B60L 2220/52 Clutch motors
• CPC Class Codes: B60L 2240/443 Torque
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 7/003 Dynamic electric braking by short circuiting the motor
• CPC Class Codes: B60L 7/28 Eddy-current braking
• CPC Class Codes: B60T 1/10 by utilising wheel movement for accumulating energy, e.g. driving air compressors
• CPC Class Codes: B60W 2510/0657 Engine torque
• CPC Class Codes: F02B 67/04 of mechanically-driven auxiliary apparatus
• CPC Class Codes: F02B 75/06 Engines with means for equalising torque
• CPC Class Codes: F02D 2250/24 by using an external load, e.g. a generator
• CPC Class Codes: F02N 11/04 the motors being associated with current generators
• CPC Class Codes: F02N 11/0866 comprising several power sources, e.g. battery and capacitor or two batteries
• CPC Class Codes: F02N 2011/0885 Capacitors, e.g. for additional power supply
• CPC Class Codes: F02N 2011/0888 : DC/DC converters
• CPC Class Codes: F02N 2011/0896 : Inverters for electric machines, e.g. starter-generators
• CPC Class Codes: F16F 15/1292 : characterised by arrangements for axially clamping or positioning or otherwise influencing the frictional plates
• CPC Class Codes: F16F 15/18 : using electric, magnetic or electromagnetic means suppression of vibrations of rotating systems by use of non-rotating magnetic or electromagnetic means F16F15/03; dynamo-electric devices H02K; control effected upon generator excitation circuit to reduce harmful effects of overloads or transients H02P9/10
• CPC Class Codes: F16H 2061/0422 : by an electric machine, e.g. by accelerating or braking the input shaft
• CPC Class Codes: H02K 51/00 : Dynamo-electric gears, i.e. dynamo-electric means for transmitting mechanical power from a driving shaft to a driven shaft and comprising structurally interrelated motor and generator parts
• CPC Class Codes: H02K 7/108 : with friction clutches
• CPC Class Codes: H02M 7/00 : Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
• CPC Class Codes: Y02T 10/62 : Hybrid vehicles
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• CPC Class Codes: Y02T 10/70 : Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor
• CPC Class Codes: Y10S 903/906 : Motor or generator
• CPC Class Codes: Y10S 903/914 : Actuated, e.g. engaged or disengaged by electrical, hydraulic or mechanical means
• CPC Class Codes: Y10S 903/946 : Characterized by control of driveline clutch
• CPC Class Codes: Y10S 903/947 : Characterized by control of braking, e.g. blending of regeneration, friction braking
• CPC Class Codes: Y10S 903/96 : having chargeable mechanical accumulator

Abstract

The invention concerns a starter/generator for an internal combustion engine (1), especially that of a motor vehicle, with an electric rotary-field machine (4), which exercises the starter and generator function; and at least one invertor (17) for generating the voltages and/or currents of variable frequency, amplitude and/or phase required for the magnetic fields of the electric machine (4); wherein the electric machine (4) starts the internal combustion engine (1) by merging in from standstill.

Claims

1. Starter/generator for an internal combustion engine (1) of a motor vehicle, wherein the improvement comprises

an on-board network having a first voltage level;

an electric rotary-field machine (4), which exercises the starter and generator function; and

at least one invertor (17) to generate the voltages and currents having at least one variable including frequency, amplitude, and phase required for the magnetic fields of the electric machine (4) by sine-evaluated pulse modulation with a clock frequency greater than 10 kHz;

wherein the inverter (17) has an intermediate circuit with a second voltage level;

wherein the inverter (17) in the intermediate circuit is outfitted with an energy accumulator (19, 24) to store up energy for the starter operation;

wherein the second voltage level is higher than the first voltage level; and

wherein both the energy withdrawal from the intermediate circuit in the starter operation of the electric machine (4) and the energy storage in the intermediate circuit in the generator operation take place at the second voltage level.

2. A starter/generator according to claim 1, in which the electric machine (4) starts the internal combustion engine (1) by movement from standstill.

3. A starter/generator per claim 2, in which the relative rotary speeds of internal combustion engine (1) and electric machine (4) are equal in the starter and in the generator operation.

4. Starter/generator according to claim 1, in which the electric machine (4) is directly coupled to a drive shaft (10) of the internal combustion engine or a drive train.

5. A starter/generator according to claim 4, in which the electric machine (4) is mounted on the drive shaft (10) and firmly joined to it.

6. Starter/generator according to claim 1, in which the electric machine (4) is an induction machine.

7. Starter/generator according to claim 1, in which one rotary field generating element (stator 8) of the electric machine (4) has 8 to 16 poles (39).

8. Starter/generator according to claim 1, in which the electric machine (4) has a maximum pole reversal frequency between 300 and 1600 Hz.

9. Starter/generator according to claim 1, in which the stator (8) of the electric machine (4) has stator plates with a thickness of 0.35 mm or less.

10. A starter/generator according to claim 1, in which the electric machine (4) has winding heads which have an axial projection between 5 mm and 25 mm on each side of the stator (8) of the electric machine (4).

11. A starter/generator according to claim 1, in which the air gap between rotor (9) and stator (8) of the electric machine (4) is between 0.5 mm and 1.5 mm.

12. A starter/generator according to claim 1, in which the back thickness of the stator (8) of the electric machine (4) is between 15 mm and 30 mm.

13. Starter/generator according to claim 1, in which the electric machine (4) has an internal fluid cooling.

14. Starter/generator according to claim 1, in which the electric machine (4) works far into the magnetic saturation region at a current coverage (or maximum torque) of at least 400 to 1000 A/cm air gap length in the circumferential direction.

15. Starter/generator according to claim 1, in which the electric machine (4) has a high torque density—

in terms of the maximum torque greater than 0.01 Nm/cm³.

16. Starter/generator according to claim 1, in which electronic switches (43, 47, 50) of the invertor (17) are boiling bath cooled.

17. Starter/generator according to claim 1, in which several electronic switches (43) of the invertor (17) are connected in parallel.

18. Starter/generator according to claim 1, in which the invertor (17) contains semiconductor switches, of at least one of the following type:

field effect transistors, bipolar transistors, and bipolar transistors with insulated gate (IGBTs).

19. Starter/generator according to claim 1, in which auxiliary machines such as air conditioners (29), servo-drives (30), pumps, are electrically operated at the second voltage level from the intermediate circuit.

20. A starter/generator according to claim 1, in which the electric machine (4) also serves as a generator for heating purposes.

21. Starter/generator according to claim 1, in which a car battery is provided in the on-board network on the first voltage level.

22. Starter/generator according to claim 1, in which the electric machine (4) can produce or sustain an acceleration and/or braking of the drive shaft.

23. Starter/generator according to claim 1, in which the electric machine (4) works as an electromagnetic coupling in the drive train (2).

24. A starter/generator according to claim 1, in which the electric machine (4) also serves to reduce rotational nonuniformities by generating a quickly alternating opposite-phase torque.