Electric motor case with folded-out mounting brackets and economical motor-fan packaging
A cooling module 67 includes a motor assembly 42 having a motor case 24 having at least one open end and including mounting brackets 30 integral therewith. Each bracket has only a bottom portion 32 connected with the motor case. An armature assembly is disposed in the motor case and includes a rotatable shaft 46. A brush card assembly 56 is associated with the armature assembly, and an end cap 60 is disposed over the brush card assembly and partially covers the open end of the motor case and thereby defining a non end cap covered motor portion 63. A fan 64 is coupled to an end of the shaft and has a hub substantially covering one end of the motor assembly. A shroud 74 has a motor cover 76. Fastening structure 78 is associated with the shroud and engaged with the brackets thereby mounting the motor assembly to the shroud, with the motor cover substantially covering the end cap and the non end cap covered motor portion.
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This application claims the benefit of the earlier filing date of U.S. Provisional Application No. 60/702,473, filed on Jul. 26, 2005, which is incorporated by reference herein in its entirety.
FIELD OF THE INVENTIONThis invention relates to Permanent Magnet Direct Current (PMDC) motors for automotive applications such as engine cooling.
BACKGROUND OF THE INVENTION Electric motors used in engine cooling applications need some type of mounting feature on the end cap or motor case (stator assembly) to provide adequate fastening to a shroud. The stator assembly is the stationary member of the electric motor. The two most commonly used features are shown
Conventional motor to shroud attachments are illustrated in
The welded brackets 12 of motor 10 increase the overall cost of the system due to the cost of three brackets and the cost of a welding operation. The flanges 15 on the end cap of motor 10′ increase the overall system cost due to the cost of a larger and thicker piece of material used to make the end cap having the flanges.
Since there is a high demand to reduce the system cost of the engine cooling module, there is a need to reduce the cost of the attachment mechanism of a motor to a shroud.
SUMMARY OF THE INVENTIONAn object of the present invention is to fulfill the need referred to above. In accordance with the principles of the present invention, this objective is obtained by providing a cooling module including a motor assembly having a motor case defining a stator of generally cylindrical shape having at least one open end. The motor case includes a plurality of mounting brackets integral therewith at the open end. Each mounting bracket has only a bottom portion connected with the motor case with side portions of each bracket being separated from the motor case by cut-out portions in the motor case. An armature assembly is disposed in the motor case for rotation with respect to the motor case. The armature assembly includes a shaft that rotates therewith. A brush card assembly is associated with the armature assembly. An end cap is disposed over the brush card assembly and partially covers the open end of the motor case, thereby defining a non end cap covered motor portion. A fan is coupled to an end of the shaft and has a hub substantially covering one end of the motor assembly. A shroud has a motor cover. Fastening structure is associated with the shroud and engaged with the brackets thereby mounting the motor assembly to the shroud, with the motor cover substantially covering the end cap and the non end cap covered motor portion.
In accordance with another aspect of the invention, a stator is provided for a permanent magnet DC motor. The stator includes a motor case of generally cylindrical shape having at least one open end. The case includes a plurality of mounting brackets integral therewith at the open end. Each mounting bracket has only a bottom portion connected with the motor case with side portions of each bracket being separated from the motor case by cut-out portions in the motor case. Each mounting bracket is folded-out about the bottom portion thereof with respect to the motor case for use in mounting the motor case to a shroud.
In accordance with yet another aspect of the invention, a method of mounting a motor assembly to a shroud provides a motor assembly having a motor case of generally cylindrical shape having at least one open end. An end cap partially covers the open end. The motor case defines a central axis and includes a plurality of mounting brackets integral therewith at the open end. Each mounting bracket has only a bottom portion connected with the case with side portions of each bracket being separated from the motor case by cut-out portions in the motor case. The mounting brackets are bent about the bottom portion thereof with respect to the motor case so as to be generally transverse with respect to the central axis. A shroud is provided having a motor cover. The motor case, and thus the motor assembly, is mounted to the shroud by engaging a fastener, associated with the motor cover, with each of the brackets such that the motor cover substantially covers the end cap and open end of the motor case.
Other objects, features and characteristics of the present invention, as well as the methods of operation and the functions of the related elements of the structure, the combination of parts and economics of manufacture will become more apparent upon consideration of the following detailed description and appended claims with reference to the accompanying drawings, all of which form a part of this specification.
BRIEF DESCRIPTION OF THE DRAWINGSThe invention will be better understood from the following detailed description of the preferred embodiments thereof, taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts, in which:
With reference to
As shown in
The brackets 30 are folded out (bent) about the bottom portion 32 to extend from the motor case 24 (e.g., generally transverse with respect to the central axis C) so as to provide optimum structural support with minimum magnetic flux loss in the motor. Each bracket 30 includes fastener engagement structure preferably in the form of a through hole 40 receiving a fastener, for securing the motor case 24 to a shroud, as will be explained more fully below.
The preferred radial position (with respect to the central axis C) for each bracket 30 is at the edge of the magnetic flux circuit. This position typically would be at middle of a magnet 26 that is mounted to the inside of the motor case 24 as best shown in
With reference to
Instead of mounting the shroud 74 to the motor-fan assembly as in
The foregoing preferred embodiments have been shown and described for the purposes of illustrating the structural and functional principles of the present invention, as well as illustrating the methods of employing the preferred embodiments and are subject to change without departing from such principles. Therefore, this invention includes all modifications encompassed within the spirit of the following claims.
Claims
1. A cooling module comprising:
- a motor assembly comprising: a motor case defining a stator of generally cylindrical shape having at least one open end, the motor case including a plurality of mounting brackets integral therewith at the open end, each mounting bracket having only a bottom portion connected with the motor case with side portions of each bracket being separated from the motor case by cut-out portions in the motor case, and an armature assembly disposed in the motor case for rotation with respect to the motor case, the armature assembly including a shaft that rotates with the armature assembly, a brush card assembly associated with the armature assembly, and an end cap disposed over the brush card assembly and partially covering the open end of the motor case and thereby defining a non end cap covered motor portion,
- a fan coupled to an end of the shaft, the fan having a hub substantially covering one end of the motor assembly,
- a shroud having a motor cover, and
- fastening structure associated with the shroud and engaged with the brackets thereby mounting the motor assembly to the shroud, with the motor cover substantially covering the end cap and the non end cap covered motor portion.
2. The module of claim 1, wherein the motor case defines a central axis and each bracket is folded out so as to be generally transverse with respect to the central axis.
3. The module of claim 2, wherein the motor assembly includes permanent magnet structure mounted to the motor case in an interior thereof.
4. The module of claim 3, wherein the permanent magnet structure includes four permanent magnets, and at least three spaced brackets are provided, a radial position of at least two of the brackets with respect to the central axis being generally centered with respect to an associated magnet.
5. The module of claim 1, wherein each bracket includes a surface defining a hole and wherein the fastening structure is a thread forming screw engaged with an associated hole.
6. The module of claim 1, wherein the fastening structure is a rivet.
7. The module of claim 1, wherein the end cap includes a bushing assembly that supports an end of the shaft for rotation.
8. A method of mounting a motor assembly to a shroud, the method including:
- providing a motor assembly having a motor case of generally cylindrical shape having at least one open end, an end cap partially covers the open end, the motor case defines a central axis, the motor case includes a plurality of mounting brackets integral therewith at the open end, each mounting bracket having only a bottom portion connected with the case with side portions of each bracket being separated from the motor case by cut-out portions in the motor case,
- bending the mounting brackets about the bottom portion thereof with respect to the motor case so as to be generally transverse with respect to the central axis,
- providing a shroud having a motor cover, and
- mounting the motor case and thus the motor assembly to the shroud by engaging a fastener, associated with the motor cover, with each of the brackets such that the motor cover substantially covers the end cap and open end of the motor case.
9. The method of claim 8, wherein each bracket includes a hole and the fastener is a thread-forming screw, the method includes engaging a thread-forming screw with an associated hole.
10. The method of claim 8, wherein the motor assembly includes:
- an armature assembly disposed in the motor case for rotation with respect to the motor case, the armature assembly including a shaft that rotates with the armature assembly,
- a brush card assembly associated with the armature assembly, and
- the end cap is disposed over the brush card assembly and defines a non end cap covered motor portion,
- wherein the step of providing shroud and motor cover includes ensuring that the motor cover substantially covers the end cap and the non end cap covered motor portion.
11. The method of claim 10, wherein the shaft has an end extending from a second end of the motor case opposite the open end thereof, the method further includes coupling a fan to the end of the shaft, the fan having a hub constructed and arranged to substantially cover the second end of the motor case.
12. A stator for a permanent magnet DC motor, the stator comprising:
- a motor case of generally cylindrical shape having at least one open end, the case including a plurality of mounting brackets integral therewith at the open end, each mounting bracket having only a bottom portion connected with the motor case with side portions of each bracket being separated from the motor case by cut-out portions in the motor case, each mounting bracket being folded-out about the bottom portion thereof with respect to the motor case for mounting the motor case to another object.
13. The stator of claim 12, wherein the motor case defines a central axis and each bracket is folded out so as to be generally transverse with respect to the central axis.
14. The stator of claim 13, further including permanent magnets mounted to an interior of the motor case, a radial position of certain brackets with respect to the central axis being generally centered with respect to an associated magnet
15. The stator of claim 12, wherein four permanent magnets are provided and at least three spaced brackets are provided, at least two of the brackets define the certain brackets that are generally centered with respect to an associated magnet.
16. The stator of claim 12, in combination with an armature assembly disposed in the motor case, the motor case including permanent magnet structure fixed with respect to an interior of the motor case and associated with the armature assembly.
17. The combination of claim 16, in further combination with a shroud, the shroud including a motor cover, wherein fastening structure, associated with the motor cover, is engaged with the brackets mounting the motor case to the shroud.
18. The combination of claim 17, wherein each bracket includes a surface defining a hole receiving fastening structure in the form of a thread-forming screw.
19. The combination of claim 17, wherein the fastening structure is a rivet.
20. The stator of claim 12, wherein each bracket includes fastener engagement structure constructed and arranged to engage fastening structure.
Type: Application
Filed: Apr 21, 2006
Publication Date: Feb 1, 2007
Applicant: Siemens VDO Automotive Inc. (London)
Inventors: Attila Simofi-Ilyes (London), Stefan Smorowski (London), Andrew Lakerdas (London), Paul McLennan (London), Ovidius Turcanu (London)
Application Number: 11/407,933
International Classification: H02K 5/00 (20060101); H01R 39/38 (20060101);