DE102009045218A1 - Electric machine with power electronics - Google Patents

Abstract

The present invention relates to an electric motor or generator assembly, and more particularly to an electric motor or generator having a power electronics housing for providing an electrical current for driving the motor or for removing an electrical current from the generator. The electrical machine assembly (1) comprises a housing (2), an electric machine (6) housed within the housing, and a power electronics assembly (12) including one or more semiconductor power switching devices (18) for driving the power unit to switch electrical current, which is supplied to the electric machine or is removed therefrom. The electric machine (6) is electrically connected to a plurality of electrical terminals (24) extending through the housing (2) for external electrical connection to the electric machine and to the power electronics assembly (12). comprising a printed circuit board (14) on the first side (15) of which the semiconductor power switching devices (18) are mounted in an edge portion of the printed circuit board (14). The semiconductor power switching devices (18) are mounted in a peripheral portion of the printed circuit board (14). The plurality of electrical terminals (24) are electrically connected to a central portion of the printed circuit board (14). The second side (16) of the circuit board is attached to an external portion (10) of the housing (2), so that the housing as a ...

Description

GENERAL PRIOR ART

a. Field of the invention

The The present invention relates to an electric motor or generator assembly and in particular an electric motor or generator with a power electronics housing for Providing an electrical current for driving the motor or for removing an electrical current from the generator.

b. Related Technology

The Use of high performance electric motors is used in motor vehicles due to advances in semiconductor technology and the necessary Improvement of fuel economy and vehicle performance always more common Examples include the use of electric motors in hybrid vehicles, around on the street running wheels energy and the use of starters for high performance engines in vehicles where the engine is switched off each time, when the vehicle is stationary. The typical power consumption of such High performance electric motors range from 2 kW to 20 kW. The electrical power for operating such electric motors can be provided with 12 to 400 volts DC.

One Vehicle starter usually serves as well as a motor driven generator. Similar serve in a hybrid vehicle, the electric motors of the wheels as electric generators when the vehicle is braking. The term "electrical Machine", as used in this description, both on electric motors as well as on generators.

In The control electronics is in every high-power electrical machine necessary, high currents into the coils of the machine in an appropriate order, to power the machine. The semiconductor switches, which are normally used to switch the high currents, are usually mounted directly on a heat sink to dissipate the heat, which is generated within the semiconductor power switch. The Control electronics for controlling the switching of the semiconductor power switches is mounted on a separate circuit board, which connects to the semiconductor power switch by means of a rigid connector or a flexible printed circuit board connector can be connected.

Even though this arrangement an effortless access There is, if there ever is, on the various circuit boards and components should be necessary to repair the power electronics or to replace the assembly of power converter, control electronics and heat sink relatively expensive.

It is an object of the present invention, a more practical and cost-effective to provide an electrical machine assembly comprising an electric motor or a generator and power electronics for driving of the electric motor or the generator.

BRIEF SUMMARY OF THE INVENTION

• – die Halbleiter-Leistungsschaltvorrichtungen in einem Randabschnitt der Leiterplatte montiert sind;
• – die Vielzahl der elektrischen Anschlüsse elektrisch an einen mittleren Abschnitt der Leiterplatte angeschlossen ist; und
• – die zweite Seite der Leiterplatte an einen externen Abschnitt des Gehäuses angefügt ist, so dass das Gehäuse als erste Wärmesenke für die Halbleiter-Leistungsschaltvorrichtungen dient.

According to the invention, there is provided an electrical machine assembly comprising a housing, an electrical machine housed within the housing, and a power electronics assembly having one or more semiconductor power switching devices for switching the electrical current supplied to or removed from the electrical machine The electrical machine is electrically connected to a plurality of electrical terminals that extend through the housing to make an external electrical connection with the power electronics assembly that includes a printed circuit board on the first side of which the semiconductor power switching devices are mounted, wherein:

• - The semiconductor power switching devices are mounted in a peripheral portion of the circuit board;
• - The plurality of electrical connections is electrically connected to a central portion of the circuit board; and
• - The second side of the circuit board is attached to an external portion of the housing, so that the housing serves as a first heat sink for the semiconductor power switching devices.

The Assembly provides a space-saving and robust assembly of the assembly from electrical machine and power electronics ready and used the material of the case as a heat sink for the semiconductor power switching devices.

The PCB can with heat paths be formed between the first and second sides of the plate, to conduct the heat from the first side of the plate to the second side of the plate. The areas on the plate that have these heat paths conduct prefers heat from one side of the plate to the other compared to other areas, not over have these paths. The heat paths can Be vias in the circuit board.

The second side of the circuit board can be contacted with an external portion of the housing by means of a thermal grease. This contacting ensures a secure assembly and also uses the thermal mass of the Ge housing as a heat sink for the semiconductor power switching devices.

The casing has a substantially cylindrical shape, which is located on an axis extending along the electrical machine, and the circuit board is at an external end surface of the housing added, which extends transversely to the axis. In this case, the circuit board preferably round.

The Semiconductor power switching devices are preferably used in one annular edge portion the printed circuit board mounted. This contributes to the devices as far as possible keep it apart and maximize the area of the assembly, from the heat over one or more heat sinks can be removed.

The casing can have one or more channels include to a coolant into the assembly, the at least one channel near the external section of the housing includes, to which the circuit board is attached. The coolant may serve to cool both the electric machine and the power electronics assembly.

It can also have a second heat sink in contact with the semiconductor power switching devices be used on the first page of the circuit board. It can is a passive heat sink, the one big one lateral surface which is provided by ribs, from which excess heat through Transfer convection to the air can be.

BRIEF DESCRIPTION OF THE DRAWINGS

The Invention will now be described by way of example and with reference to the accompanying drawings Drawings closer described. Show it:

1 a schematic view of an electrical machine assembly according to a preferred embodiment of the invention with an electric machine, which is housed in a housing, and a power electronics module, which is mounted externally at one end of the housing; and

2 a cross section through a part of the power electronics module and the housing 1 ,

DETAILED DESCRIPTION

1 and 2 show an electrical machine assembly 1 , which in this example is a generator / starter assembly for a motor vehicle. The module is based on a housing 2 of which a part is shown cut open to the windings 4 an electric machine 6 exposed, which are held in the housing. The electric machine 6 serves as a generator to generate electric power to charge a battery (not shown) and as a starter for an internal combustion engine (not shown).

The housing 2 is generally cylindrical in shape and extends along an axis 8th , The housing 2 has a substantially flat end surface 10 , which are transverse to the axis 8th extends on which a power electronics module 12 is mounted. The power electronics module is based on a printed circuit board 14 which has a middle dielectric layer sandwiched between a pair of printed conductive layers 15 . 16 is inserted, comprising (not shown) traces to transmit electrical power.

A certain number of semiconductor power switching devices 18 is around the circular circumference of the plate 14 mounted around and serves together with other circuit elements, which include a microcontroller 20 heard in a middle section of the plate, as a control device for the electricity coming from the electric machine 6 generated or this is supplied. The power and control semiconductor devices 18 . 20 are preferably surface mounted devices that are electrically accurate to the outside 15 the plate 14 are connected.

The layers 15 . 16 are under each of the power switching devices 18 in separate grid arrangements 22 so that the heat generated by the devices is effectively removed from the layer 15 on which the devices are mounted, to the opposite layer 16 which is the end surface 10 facing the housing.

The electric machine 6 includes a variety of electrical connections 24 moving through the case 2 extend. At least some of these connections 24 are electrically connected to a central portion of the circuit board 14 but some may protrude from the plate to make external electrical connections.

The inside 16 the circuit board is on the external surface 10 of the housing, so that the housing as a first heat sink for the semiconductor power switching devices 18 serves.

The conductive layers 15 . 16 on the opposite sides of the plate 14 are metallized by an intermediate insulating material 28 separated. The thickness of each of the metallized layers 15 . 16 is greater than the thickness of the interposed insulating layer 28 , This contributes to it in maximizing the plate's ability to absorb heat from the semiconductor device 18 away and to the housing 2 to lead.

The power electronics module 12 is thermal with the housing end face 10 by means of a thin layer of thermal grease 30 contacted. The housing can also by means of one or more screws 32 be attached.

2 shows a cross section through part of the power electronics module 12 and the case 2 , 2 also shows a channel 34 for conveying a coolant within the assembly, near the external portion 10 of the housing to which the circuit board 14 is attached. The coolant channel 34 therefore serves to excess heat both from the electric machine 6 as well as from the circuit board 14 to remove.

Optionally, a passive heat sink comprising cooling fins (not shown) may engage the upper sides 36 the semiconductor devices 18 . 20 in physical contact.

The The arrangement described above is particularly space-saving, since both the control as well as the power electronics are on the same Plate, together with the electrical connections for the electrical Machine. There will be a grid arrangement of vias provided to heat preferred from below each power semiconductor device into the the housing provided heat sink to lead. The invention therefore provides a practical and inexpensive electrical Machine assembly ready to use an electric motor or generator and a power electronics for driving the electric motor or Generators includes.

Claims (10)

An electrical machine assembly comprising Casing, an electric machine housed in the housing, and a power electronics assembly including one or more semiconductor power switching devices for switching the electric current, that of the electric machine supplied or is taken from it, wherein the electric machine is electrically Connected to a variety of electrical connections that are through the housing extend through to an external electrical connection with to manufacture the power electronics assembly, which is a printed circuit board includes, mounted on the first side of the semiconductor power switching devices are, where: - the Semiconductor power conversion devices in an edge portion of Printed circuit board are mounted; - the variety of electrical connections electrically connected to a central portion of the circuit board is; and - the second side of the printed circuit board is attached to an external portion of the housing, leaving the case as first heat sink for the Semiconductor power switching devices serves. An electric machine assembly according to claim 1, wherein the printed circuit board with heat path between the first and second sides of the plate is formed to lead to the heat from the first side of the plate to the second side of the plate. Electrical machine assembly according to claim 1 or 2, wherein the second side of the circuit board with an external section of the housing by means of a thermal compound will be contacted. Electrical machine assembly according to the preceding claims, the housing being a has substantially cylindrical shape, which is located on an axis extending along the electrical machine, and the circuit board to an external end surface of the housing added is, which extends transversely to the axis. Electrical machine assembly according to one of the preceding Claims, wherein the semiconductor power switching devices in an annular peripheral portion the circuit board are mounted. Electrical machine arrangement according to one of the preceding Claims, the housing has a or more channels includes a coolant within the assembly, the at least one channel near the external section of the housing includes, to which the circuit board is attached. Electrical machine assembly according to one of the preceding Claims, additionally comprising a second heat sink, the second heat sink with the semiconductor power switching devices on the first page the printed circuit board is in contact. Electric machine according to one of the preceding Claims, wherein the circuit board has a circular outline, wherein the semiconductor power switching devices in a circular Pattern around the outside the circuit board are mounted around. Electric machine according to one of the preceding claims, wherein the circuit board has a conductive layer metallized on the first and second sides, and an intermediate insulating layer between the metallized layers, wherein the thickness of each of the metallized Layers is greater than the thickness of the intermediate insulating layer. Electrical machine assembly, essentially as described herein with reference to the accompanying drawings or shown in it.