Patent Application
20100038988
The present invention relates to electric motors. More specifically, the present invention relates to a stator for an electric motor.
Stators are normally formed of a series of thin, flat plates or laminations stacked to form a solid body stack or core. Coils or windings are positioned in pre-formed slots in the plates, extending through the stack, with ends of the coils looping at each end of the stack to form end turns for a continuous closed circuit electrical path.
Manufactures have developed stators with differing conductor winding segments, which are analogous to the above-mentioned coil loops at each end of the stack. For example, a method of manufacturing a stator having a stator winding formed by a plurality of U-shaped conductor segments is described in JP-B2-3196738. In this example, the U-shaped conductor segment has a pair of conductors inserted into slots formed in a stator core. One conductor of the U-shaped conductor segment is inserted into one slot, while the other conductor is inserted into another slot which is apart from the one slot by a pole pitch. After plural conductor segments are all inserted into the slots, axial ends of conductors are connected to one another forming a stator winding.
An L-shaped conductor segment has also been described in JP-A-2001-37131, which describes a stator having a stator winding formed by plural L-shaped conductor segments. The L-shaped conductor segments are inserted into slots of the stator core from both axial ends thereof. Then, axial ends of the L-shaped conductor segments are electrically connected to one another to form a stator winding.
Recently, manufactures have begun using rod shaped chips for conductor segments. For instance, U.S. Pat. No. 6,548,933 describes sandwiching a stator tooth portion to adjacent slots. Using a thin plate rod shape chip between both ends of U-shape side of the coil, the coil is connected and the coil is formed to have one winding close circuit. The plural coils are inserted between the both ends of an anti-U-shape side is connected, and a stator coil for forming a predetermined winding turn number is obtained.
However, none of the above mentioned descriptions sufficiently reduce the amount of necessary conductive material or sufficiently decrease the costs of production. Furthermore, none of the above descriptions have sufficient flexibility for configuring the motor windings into a multitude of electrical design configurations.
Accordingly, to date, there is no suitable endcap assembly or method for sufficiently reducing the amount of conductive material used in the production of stator cores.
The present disclosure describes an endcap assembly for a stator of an electric motor, and a method of making a stator.
In an embodiment of the present invention, the endcap assembly comprises a dielectric material and a plurality of connection paths each being supported by the dielectric material and each intervening between each turn of the stator winding and wherein the connection paths are configured to communicate with each terminal end of a stator conductor.
In another embodiment of the present invention, the invention provides a method of making a stator for an electric motor comprising providing a stator core having a plurality of conductor winding slots, locating a plurality of conductor windings into the stator core, each conductor winding have at least one terminal end, and providing at least one endcap assembly and connecting the at least one endcap assembly at a first and second side of the stator core, wherein the connection paths are configured to communicate with each terminal end of a stator conductor thereby forming a continuous conductor winding. The endcap assembly comprises a dielectric material and a plurality of connection paths each being supported by the dielectric material and each intervening between each turn of the stator winding.
Other features and advantages of the disclosure will become apparent by reference to the following description taken in connection with the accompanying drawings.
Reference is now made briefly to the accompanying drawings, in which:
Like reference characters designate identical or corresponding components and units throughout the several views, which are not to scale unless otherwise indicated.
One embodiment of the present invention involves an endcap assembly which comprises a substrate and a plurality of connection paths each intervening between each turn of a stator winding, which in turn, allows for electrical communication between the connection paths and the terminal ends of the stator conductor. Two particular advantages afforded by this invention is the ability to manufacture stator cores using substantially less superfluous conduction material (e.g., magnet wire) in the endturns of a stator, and the ability to allow for a single endcap assembly to be used with a myriad of different stator conductor configurations, each of which may be applicable to a number of different stator design requirements.
Specific configurations and arrangements of the claimed invention, discussed below with reference to the accompanying drawings, are for illustrative purposes only. Other configurations and arrangements that are within the purview of a skilled artisan can be made, used, or sold without departing from the spirit and scope of the appended claims. For example, while some embodiments of the invention are herein described with reference to an electric motor, a skilled artisan will recognize that embodiments of the invention can be implemented in any setting in which acute electrical turns are desirable.
As used herein, an element or function recited in the singular and proceeded with the word “a” or “an” should be understood as not excluding plural said elements or functions, unless such exclusion is explicitly recited. Furthermore, references to “one embodiment” of the claimed invention should not be interpreted as excluding the existence of additional embodiments that also incorporate the recited features
Referring now to
The stator laminated core may comprise conductor wiring slots 108 disposed between conductor wiring teeth 110. The stator lamination core may be configured to accommodate at least one embedded conductor in the form of conductor windings (not shown).
Referring now to
The stator core 202 may be manufactured from e.g., steel, iron and the like. The stator core may be dimensioned to correspond to a plurality of motor sizes, and may be configured to reduce hysteresis and eddy current loss.
The stator conductors 204 may be manufactured from any conductive material, e.g., copper or aluminum. The conductors may be further electrically isolated from the iron core by, e.g., insulating paper. The stator conductors, when coupled to the stator end cap assemblies, allow for a closed circuit electrical path and, in turn, the production of a magnetic field when current is passed therethrough. In an embodiment of the present invention, the conductors may be formed into a predetermined arrangement in a stator slot, allowing a uniform, stacked, layered formation. However, in an optional embodiment, the conductors may be positioned in a random orientation, in which the conductors are randomly arranged in a stator slot. In yet another optional embodiment of the present invention, the formed or randomly arranged conductors may be precoupled to at least one endcap on one side of the stator and inserted into stator core, e.g., via an injection mechanism. The endcap assemblies 208 and 210 may attach at the terminal ends of the stator conductors.
The endcap assemblies 208 and 210, which will be discussed in greater detail with reference to
Now with reference to
In an exemplary embodiment of the present invention, the connection paths 302 may be manufactured of a conductive material such as copper or aluminum. The plurality of connection paths 302 may each be intervening between each turn of the stator winding, which comprise a plurality of conductors, at 310. In turn, each connection path may be configured to communicate with each terminal end of the stator conductor 306. In other words, the connection paths may be aligned with the terminal ends of the stator conductors to complete a closed loop circuit.
With further reference to
At connection point 312, the connection paths may reside in a plane that approximately orthogonal to a longitudinal axis of each stator conductor 306, while further residing circumferentially along an inner surface of the dielectric material 304. In optional embodiments of the present invention, the connection paths may be configured in a layered formation as required by motor performance design, which will be discussed in greater detail with reference to
Referring now to
In another embodiment of the present invention, the endcap assembly may comprise a heavy copper printed circuit board.
In this exemplary embodiment of the present invention, the circuit board may be layered, and thus may comprise external traces 504, connected via line 508, and internal traces 510 connected via line 514. While, as shown, the exemplary circuit is a two-layer circuit board, it is to be appreciated that a plurality of layers may be envisioned to match a plurality of stator conductor and motor configurations. For example, the endcap may include internal traces 516 connected via line 518 disposed circumferentially around the endcap, in a plane that is below the internal traces 510. Furthermore, the endcap may include cotraces (not shown) for making electrical connections from layer to layer. This exemplary arrangement may also allow for a single endcap to be used with a myriad of different stator conductor configurations, each of which may be applicable to a number of different stator design requirements.
It is to be appreciated that each embodiment of the stator core and endcap assembly may further comprise a connector for insertion of an external power source (not shown) for providing power to the stator.
Referring now to
Referring now to
Providing a stator laminated core having a plurality of conductor winding posts 702 may comprise a combination of stator laminations, such as those shown in
Locating a plurality of conductor windings into the stator core, each conductor winding have at least one terminal end 704 may comprise providing formed individual rectangle wires dimensioned to correspond to winding slots in a stator core, allowing for a uniform, stacked, layered formation. However, in an optional embodiment, the conductors may be positioned randomly, in which the conductors are randomly arranged within the stator slot. In yet another optional embodiment of the present invention, the formed or randomly arranged conductors may be precoupled to at least one endcap and then be inserted into the stator core post-production via auto-injection.
Each of the conductor windings may have at least one terminal end. What is meant by “terminal end” is that each of the conductor windings comprises an end portion wherein the winding is incomplete until the addition of an endcap assembly, which may then complete the conductor winding and form a closed loop circuit. Forming a terminal end may comprise cutting or stripping the completed windings at their outer-most periphery, or inserting or injecting wires into the core that have been preformed to comprise a terminal end. The terminal end of each conductor winding may extend outside of the frame as shown in
Providing at least one endcap assembly, the endcap assembly comprising a substrate and a plurality of connection paths each being supported by the substrate and each intervening between each turn of the stator winding and wherein the connection paths are configured to communicate with each terminal end of a stator conductor 706 may comprise, for example as shown in
When the endcap assemblies are attached, the terminal ends of the stator conductors and the endcap assembly connection paths connect to form a closed circuit, and complete the stator windings, as shown in
Although specific features of various embodiments of the invention may be shown in some drawings and not in others, this is for convenience only. In accordance with the principles of the invention, the feature(s) of one drawing may be combined with any or all of the features in any of the other drawings. The words “including”, “comprising”, “having”, and “with” as used herein are to be interpreted broadly and comprehensively and are not limited to any physical interconnection. Moreover, any embodiments disclosed herein are not to be interpreted as the only possible embodiments. Rather, modifications and other embodiments are intended to be included within the scope of the appended claims.
