Patent Application
20240243622
The present disclosure relates to electric motors, and more particularly to maintenance of electric motor components.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Electric propulsion systems in vehicles use electric motors to propel the vehicle as an alternative or in addition to internal combustion engines. Generally, varnish is applied to the electric motors to protect against corrosion and contaminant, thereby improving an operation life of the electric propulsion system. The varnish can be applied with a machine designed to apply the varnish to various components of the motors. During application, varnish may flow away from an intended location or component that uses the varnish, increasing the total amount of varnish used and potentially disrupting operation of other parts of the electric motor.
The present disclosure addresses challenges related to varnish application to electric motors.
This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.
A stator assembly for an electric motor includes a stator core including a cylindrical body defining a bore providing an inner surface, a plurality of wire slots extending radially outward from the inner surface, and a containment zone disposed radially outward of the plurality of wire slots. The containment zone is configured to contain fluid applied to a surface of the stator core spaced from the wire slot.
In variations of the assembly, which may be implemented individually or in combination: the cylindrical body comprises a plurality of laminates, and the containment zone is defined in an outermost one of the plurality of laminates; the cylindrical body further defines a fastener slot, wherein the containment zone is disposed radially inward of the fastener slot; the stator core further comprises a visible pattern formed on an outer surface of the cylindrical body, wherein the containment zone is disposed radially inward of the visible pattern; the containment zone is a chamber defined within the cylindrical body; the chamber is defined between an outermost laminate and an adjacent laminate.
In another form, a laminate for a stator core includes an annular body defining an inner edge, a plurality of wire slots extending radially outward from the inner edge, and a containment zone disposed radially outward of the plurality of wire slots. The containment zone is configured to contain fluid applied radially outward from the plurality of wire slots.
In variations of the laminate, which may be implemented individually or in combination: further including an adhesive disposed radially outward of at least one of the plurality of wire slots; the containment zone is disposed radially outward of the adhesive; the containment zone is disposed between the adhesive and at least one of the plurality of wire slots; further including a visible pattern formed on an outer surface of the annular body, wherein the containment zone is disposed radially inward of the visible pattern; the annular body further defines a fastener slot, wherein the containment zone is disposed radially inward of the fastener slot; the annular body further defines a plurality of containment zones disposed circumferentially around the laminate; the containment zone is a hole extending through the annular body; the hole is substantially arcuate.
In another form, a stator core assembly for an electric motor includes a stator core including a plurality of laminates arranged in an axial direction, each laminate defining a plurality of wire slots extending radially from an inner edge. The plurality of laminates includes an outermost laminate defining a containment zone disposed radially outward of the plurality of wire slots of the outermost laminate and extending axially toward an adjacent laminate. The containment zone of the outermost laminate is configured to collect fluid applied on an outermost surface of the stator core away from the plurality of wire slots.
In variations of the assembly, which may be implemented individually or in part: further including an adhesive adhering adjacent ones of the plurality of laminates, wherein the containment zone is disposed radially outward of the adhesive; further including an adhesive adhering adjacent ones of the plurality of laminates, wherein the containment zone is disposed radially between the adhesive and at least one of the plurality of wire slots; the containment zone is a chamber defined by a hole extending through the outermost laminate to an adjacent laminate; the stator core further comprises a visible pattern formed on an outer surface of the cylindrical body, wherein the containment zone is disposed radially inward of the visible pattern.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
In order that the disclosure may be well understood, there will now be described various forms thereof, given by way of example, reference being made to the accompanying drawings, in which:
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
Among other components, an electric motor includes a stator that is a stationary component generating an electromagnetic field and a rotor which rotates relative to the stator due to the electromagnetic field. The electric motor is a component of an electric propulsion for a motor vehicle such as an “electric vehicle.” The electric motor propels the motor vehicle by rotating one or more wheels of the motor vehicle. In one example, the electric motor is a sole propulsion of the vehicle, such as in a fully electric vehicle. Alternatively, the electric motor can be part of a hybrid propulsion that includes an internal combustion engine, such as in a hybrid-electric vehicle.
With reference to
In one form, one or more wires 24 from among the plurality of wires 24 reside in each slot 32. The wires 24 are formed of an electrically conducting material, such as copper. With the wires 24 arranged in the slots 32, electric current flow through the wire 24 generating electromagnetic field that drives the rotor.
With reference to
In one application, the stator core 22 includes a plurality of laminates 40, including an outermost laminate 40a as shown in
In one form, the laminates 40 include an adhesive 56 that adheres the annular body 42 of one of the laminates 40 with an adjacent laminate 40 of the stator core 22. The adhesive 56 is applied to the annular body 42 in a suitable manner, shown as dots of adhesive 56. The adhesive dots 56 are arranged circumferentially around the annular body 42 radially outward of the plurality of wire slots 46 to provide substantially consistent adhesion to the other laminate 40. In one form, the adhesive 56 is disposed both radially inward and outward of the containment zones 50, described below. In other forms shown below, the adhesive 56 is disposed between the containment zones 50 and the wire slots 46. In yet another form not shown, the adhesive 56 is disposed only radially outward of the containment zones 50. In yet another form, the stator core 22 lacks adhesive 56 entirely, and the laminates 40 are joined by another method such as welding.
The laminates 40 define at least one containment zone 50 disposed radially outward of the plurality of wire slots 46. In this context, a “containment zone” is a portion of the laminates 40 configured to contain fluid (such as varnish) applied to a surface of the stator core 22. In the form of
Referring back to
In another form, the voids defining the containment zones 50 have different shapes, such as outer arcuate slots, inner angular slots, substantially straight slots, sinusoidally-shaped slots, and combinations thereof. In addition, one or more voids having same or different shapes may be employed in each containment zone 50. The containment zones 50 thus collect varnish that could otherwise interfere with other parts of the stator core 22.
With reference to
Now referring to
Another specific portion of the laminate 80 may include a visible pattern 88 that provides identifying information about the electric motor. The visible pattern 88 is formed on an outer surface of the annular body 82 for detection by a vision system or laser reader. The varnish, which may be opaque or glossy, may interfere with readability of the visible pattern 88. The containment zone 84 thus is disposed radially inward of the visible pattern 88 to inhibit the varnish from interfering with the visible pattern 88. By using fewer containment zones 84 focused on specific portions of the laminate 80, less of the annular body 82 is removed, and the overall strength of the laminate 80 is increased relative to the laminates 40, 60 shown in
In another form, not shown in the FIGS., the stator core may be a monolithic body, i.e., formed of a single piece of material into which the containment zones are defined. In such a form, the containment zones may be voids that are machined out of the monolithic stator core or defined during an additive manufacturing process that builds the stator core. As an example, when the stator core is additively manufactured, additively layered material may be placed to define a void between adjacent portions of the layers. As additional layers of material are placed, the layers form walls delimiting the void, these walls and the void defining the containment zone. In yet another form, the laminates 40, 60, 80 described above may be additively manufactured to define the containment zones 50, 64, 84.
Unless otherwise expressly indicated herein, all numerical values indicating mechanical/thermal properties, compositional percentages, dimensions and/or tolerances, or other characteristics are to be understood as modified by the word “about” or “approximately” in describing the scope of the present disclosure. This modification is desired for various reasons including industrial practice, material, manufacturing, and assembly tolerances, and testing capability.
As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”
The description of the disclosure is merely exemplary in nature and, thus, variations that do not depart from the substance of the disclosure are intended to be within the scope of the disclosure. Such variations are not to be regarded as a departure from the spirit and scope of the disclosure.
