Electrical generator or motor structure – Dynamoelectric – Rotary
Reexamination Certificate
1999-04-19
2001-03-06
Dougherty, Thomas M. (Department: 2834)
Electrical generator or motor structure
Dynamoelectric
Rotary
C310S054000, C310S064000, C310S089000
Reexamination Certificate
active
06198183
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to an electric drive unit that includes an electric motor as well as an electronic module for controlling and monitoring the operation of the motor.
BACKGROUND INFORMATION
Electric drive units are coming into use in a great variety of applications. For example among motor vehicles, the use of low-emission vehicles that derive at least a portion of their main drive energy and/or energy for auxiliary drives from electrical sources, is ever increasing. Typical electric drive units comprise an electric motor for providing the electrical drive power, and an electronic module for controlling and monitoring the operation of the electric motor, for example for regulating the rotational speed and output power of the electric motor.
Such electric motors, due to their high power density, must be cooled during operation and therefore are typically equipped with a cooling circuit, which is usually a water cooling circuit that uses flowing water as a cooling medium. One way of providing the water flow passages necessary for the cooling circuit, is to provide the electric motor with a double-walled housing that forms a water jacket which allows the cooling water to flow through passages arranged between the outer wall and the inner wall of the motor housing.
An electronic module for controlling and monitoring the electric motor generally includes a plurality of different functional units, such as a power unit and a control unit, for example. The electronic module is arranged as a separate and independent module that is located spaced away from or separate from the electric motor. Generally, at least one of the functional units included in the electronic module (e.g. the power unit) has a high power dissipation and must therefore be correspondingly cooled. In order to provide the necessary cooling, i.e. to carry away the dissipated heat, the electronic module conventionally includes its own separate cooling circuit that is connected in series with the cooling circuit of the electric motor by means of coupling hoses or the like. Additionally, external signal conductors and power supply cables are connected between the electronic module and the electric motor for conducting sensor signals and control signals as well as the power supply voltage between the motor and the electronic module. These external connection lines are typically embodied as cables having connector plugs connected to corresponding sockets provided on the electronic module housing and on the electric motor housing.
Several disadvantages arise from such a structural arrangement of the conventional electric drive unit with the electronic module separated from the electric motor, and especially with separate cooling circuits and external cable connections for the electric motor and for the electronic module. First, the necessary connections between the electric motor and the electronic module for achieving the overall cooling, the signal transfer, and the power transfer to realize the complete electric drive unit become complicated and give rise to problems with regard to reliability, durability, aging, wear and tear, and seal leakage problems in the coupling hoses and cables between the electric motor and the electronic module. Secondly, the surface area required for mounting the components and therewith also the total structural volume of the electric drive unit is increased. Thirdly, the assembly of the electric drive unit is rather complicated and leads to relatively high manufacturing costs.
SUMMARY OF THE INVENTION
In view of the above, it is an object of the invention to provide an electric drive unit in which an electric motor and an electronic module are more effectively and more simply integrated together, than was the case in the prior art. It is also an object of the invention to provide an electric drive unit that has a simple construction, a low cost, a high reliability, and a simplified manufacturing thereof. The invention further aims to avoid or overcome the disadvantages of the prior art, while achieving all of the prior art advantages as well as additional advantages, as apparent from the present specification.
The above objects have been achieved in an integrated electric drive unit according to the invention, comprising an electric motor and an electronic module The electric motor includes a rotor and a stator or any other known motor components arranged within a double-walled housing, wherein cooling passages forming a cooling circuit are provided between the inner wall and the outer wall of the motor housing. A cooling medium can flow through the cooling passages forming the cooling circuit. The electronic module comprises at least one functional unit that dissipates heat energy and thus requires cooling, and an electronic module housing in which the functional unit is arranged. The outer wall of the electric motor housing has an opening which provides access into the cooling passages of the cooling circuit between the outer and inner walls of the motor housing. The electronic module housing has an opening or recess at least generally corresponding to the dimensions and shape of the opening in the motor housing.
The functional unit of the electronic module that requires cooling is mounted on a cooling insert, especially in the form of a cylindrically curved cooling plate. The cooling insert is received in the recess of the electronic module housing, and is arranged in the opening of the outer wall of the electric motor housing, so that it is in direct contact with the cooling medium flowing in the cooling circuit between the inner and outer walls of the motor housing. Especially, the cooling insert protrudes into the opening in the motor housing in such a manner that the cooling insert contacts or rests against the inner wall of the motor housing.
According to the invention, the electric motor and the electronic module are combined with one another to form an integrated electric drive unit. The cooling system for the electric motor and the electronic module is combined and realized for both components in common, by using a single cooling circuit to cool both components together. Since the power dissipating functional unit of the electronic module is mounted on the cooling insert, the dissipated heat is conducted into the cooling insert. Then, since the electronic module is assembled and mounted on the electric motor so that the cooling insert protrudes into the water jacket of the motor housing, the dissipated heat is carried away from the cooling insert by the cooling medium flowing through the cooling circuit. The cooling insert may especially be arranged to contact flushly against the inner wall of the motor housing. Thereby, the cooling insert is completely integrated into the water jacket or cooling circuit, so that the electric motor and the electronic module are cooled simultaneously.
With the above integrated arrangement according to the invention, it is not necessary to provide coupling hoses or pipes between the electric motor and the electronic module to achieve the required cooling of these two components of the electric drive unit. Thus, any problems such as installation complexity and sealing difficulties associated with the use of external water conduits, e.g. hoses or pipes, for externally connecting the motor and the electronic module, are avoided.
According to a further detail of the invention, a thermal insulation layer is preferably arranged between the cooling insert and the inner wall of the motor housing. Since the inner wall of the motor housing is generally hotter than the outer wall, the heat being conducted by the inner wall could otherwise negatively influence the cooling of the electronic module via the cooling insert and as a result also impact the functionality of the electronic module, in the absence of such a thermal insulating layer. The thermal insulating layer for example comprises a high temperature resistant synthetic plastic film that is applied onto the bottom surface of the cooling insert which faces the inner wall of th
Baeumel Hermann
Bitsche Otmar
Kilian Hermann
Schuch Bernhard
Daimler-Chrysler AG
Dinh Le Dang
Dougherty Thomas M.
Fasse W. F.
Fasse W. G.
LandOfFree
Integrated electric drive unit including an electric motor... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Integrated electric drive unit including an electric motor..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Integrated electric drive unit including an electric motor... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2463253