US20160372982A1 - Motor - Google Patents

Abstract

A motor including a stator including a plurality of stator slots having stator coils disposed therein, and a rotor rotatable within the stator about a central axis. The stator includes a plurality of stator channel formed adjacent to the stator slots and extending in the axial direction of the central axis.

Description

CROSS-REFERENCE TO PRIOR APPLICATION
• This application claims priority to U.S. Provisional Patent Application No. 62/181,831, filed Jun. 19, 2015, which is hereby incorporated herein by reference in its entirety.
TECHNICAL FIELD
• The present disclosure relates generally to electric machines and, more particularly, to high power density electric machines.
BACKGROUND
• Motors may be used to convert electric energy into mechanical energy for a wide variety of applications such as, for example, industrial applications. During operation of alternating current (“AC”) induction and direct current (“DC”) motors, efficiency of the motor may be lost at least in part due to heat generation as thermal energy. The accumulation of thermal energy in an AC induction or DC motor may also cause degradation of its materials and, thus, loss of integrity of the motor, particularly in a high power density motor, which has reduced size and/or weight relative to the horsepower output by the motor.
SUMMARY
• According to the present disclosure, a motor comprises a motor housing, a stator mounted within the motor housing and having a plurality of stator slots formed therein, a plurality of stator coils disposed in at least one of the stator slots, and a rotor having a rotor core and a shaft being rotatable within the stator about a central axis, wherein the stator forms at least one stator channel, wherein the stator channels are located between the stator coils and the rotor.
• These and other aspects, features and advantages of the present disclosure will become apparent in light of the following detailed description of non-limiting embodiments, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
• FIG. 1A is a perspective view of an exemplary motor;
• FIG. 1B is a front view of the exemplary motor ofFIG. 1A;
• FIG. 1C is a rear view of the exemplary motor ofFIG. 1A;
• FIG. 2A is a perspective view of the exemplary motor ofFIG. 1A with a different blower configuration;
• FIG. 2B is a front view of the exemplary motor ofFIG. 2A;
• FIG. 2C is a rear view of the exemplary motor ofFIG. 2A;
• FIG. 3 is a cross-sectional, side view of the exemplary motor ofFIG. 1A;
• FIG. 4A is a cross-sectional, front view of a stator mounted in a motor housing of the exemplary motor ofFIG. 1A;
• FIG. 4B is an enlarged view of enlargement circle A ofFIG. 4A;
• FIG. 5 is a cross-sectional, side view of the stator and motor housing ofFIG. 4A along section line A-A;
• FIG. 6 is a rear, perspective view of the stator and motor housing ofFIG. 4A;
• FIG. 7 is a perspective view of a stator coil of the exemplary motor ofFIG. 1A;
• FIG. 8 is cross-sectional view of a portion of the stator of the exemplary motor ofFIG. 1A;
• FIG. 9 is a front view of a rotor of the exemplary motor ofFIG. 1A;
• FIG. 10 is a cross-sectional, side view of the rotor ofFIG. 9 along section line A-A;
• FIG. 11 is a perspective view of the rotor ofFIG. 9 without a deflector plate shown;
• FIG. 12 is a perspective view of the rotor ofFIG. 9 without a deflector plate, heat sink or shaft shown;
• FIG. 13 is a cross-sectional, side view of an exemplary rotor vent formed in the rotor ofFIG. 12;
• FIG. 14 is a cross-sectional, side view of an exemplary rotor vent formed in the rotor ofFIG. 12;
• FIG. 15 is a side view of an exemplary turbulator of the rotor of the exemplary motor ofFIG. 1A;
• FIG. 16A is a cross-sectional, side view of a rotor of the exemplary motor ofFIG. 1A with the turbulator;
• FIG. 16B is cut-away, perspective view of the rotor ofFIG. 16A;
• FIG. 16C is an enlarged view of enlargement circle B ofFIG. 16B;
• FIG. 17 is a front view of a rotor core lamination of the exemplary motor ofFIG. 1A;
• FIG. 18 is a front view of a rotor core of the exemplary motor ofFIG. 1A;
• FIG. 19 is a perspective view of a terminal box assembly of the exemplary motor ofFIG. 1A;
• FIG. 20 is a top view of the terminal box assembly ofFIG. 17 with a cover and gasket not shown;
• FIG. 21 is a bottom view of a fan module assembly of the exemplary motor ofFIG. 2A;
• FIG. 22 is a cut-away, perspective view of a rotor of the exemplary motor ofFIG. 1A;
• FIG. 23 is a cut-away, perspective view of another rotor configuration of the exemplary motor ofFIG. 1A;
• FIG. 24 is a cut-away, perspective view of another rotor configuration of the exemplary motor ofFIG. 1A; and
• FIG. 25 is cross-sectional, side view of the exemplary motor ofFIG. 1A.
DETAILED DESCRIPTION
• Before the various embodiments are described in further detail, it is to be understood that the present disclosure is not limited to the particular embodiments described. It will be understood by one of ordinary skill in the art that the devices described herein may be adapted and modified as is appropriate for the application being addressed and that the devices described herein may be employed in other suitable applications, and that such other additions and modifications will not depart from the scope thereof
• Although various features have been shown in different figures for simplicity, it should be readily apparent to one of skill in the art that the various features may be combined without departing from the scope of the present disclosure.
• FIGS. 1A-1C show anexemplary motor10 according to principles of the present disclosure. In this document the term “motor” has been used to represent all electric machines for simplicity. Theexemplary motor10 shown inFIGS. 1A-1C is an AC induction motor. However, it should be readily understood that many of the various features and aspects of theexemplary motor10 discussed below may be as equally applicable to other types of motors, including DC motors, as they are to AC motors. Theexemplary motor10 may be a high power density motor, which is an electric motor possessing high power output per unit volume of the motor relative to other electric motors of comparable power output. High power density motors are advantageous in applications where high power output is desired, but where space for the motor is constrained.
• Themotor10 comprises amotor assembly100,motor housing200,terminal box assembly300 and afan module assembly400. Themotor assembly100 is mounted withinmotor housing200. Theterminal box assembly300 is mounted on a bottom side of themotor housing200. Thefan module assembly400 is mounted on a top side of themotor housing200. It should be understood, however, that themotor10 can be designed in various other configurations such that theterminal box assembly300 andfan module assembly400 are mounted on various other locations of themotor housing200 than as shown depending upon intended applications for themotor10. For example, theterminal box assembly300 could be mounted on a side of themotor housing200, thefan module assembly400 could be mounted on the bottom of themotor housing200, or theterminal box assembly300 andfan module assembly400 could be mounted on any other suitable surface of themotor housing200. Additionally, as shown inFIGS. 1A-1C, themotor10 may have a first blower configuration for thefan module assembly400 in which cooling air is blown into themotor housing200, as discussed below, or, alternatively, the as shown inFIGS. 2A-2C, themotor10 may have a second blower configuration for thefan module assembly400 in which negative pressure is generated to draw cooling air through themotor housing200 and into thefan module assembly400, as discussed below.
• Themotor housing200 includes at least oneair inlet202 to allow air to pass between an exterior of themotor housing200 and an interior of themotor housing200. Themotor housing200 of theexemplary motor10 shown inFIGS. 1A-1C has fourair inlets202. However, it should be readily understood that themotor housing200 may be designed with any number ofair inlets202. Themotor housing200 includes anair outlet204, shown inFIG. 6, which may be seen through the top of themotor housing200 when thefan module assembly400 is removed. Whileair inlets202 andair outlet204 are described with the terms “inlet” and “outlet,” it should be readily understood that themotor10 in accordance with principles of the present disclosure may be designed to have reverse air flows, as will be discussed below, whereair inlets202 would serve as outlets for air moving through themotor housing200 andair outlet204 would serve as an inlet for air moving throughmotor housing200.
• With reference toFIGS. 1A-1C and 3, themotor assembly100 comprises arotor102, more clearly shown inFIG. 10, and astator104, shown inFIG. 3. Therotor102 is rotatable within thestator104 aboutcentral axis106 and is rotatably mounted to themotor housing200 withball bearings108, shown inFIG. 3, or the like.
• Referring toFIGS. 4A, 4B, 5, 7 and 8, thestator104 comprises acore pack assembly110 having a plurality ofstator slots112 formed therein. Eachstator slot112 may have one or more stator coils114 disposed therein. Eachstator coil114 has one ormore coils116, as seen inFIG. 8, where twoexemplary coils116 are shown in thesame stator slot112. Thecoils116 are positioned within thestator slots112 and insulated therein and, also, mechanically constrained against electromagnetic forces by aslot wedge118. Formed in thestator104, adjacent to eachslot wedge118, is astator channel120. Thestator channels120 are located in between the stator coils114 and therotor102. Thestator104 includes one or more phase rings122 to electrically connect the stator coils114.
• Referring toFIGS. 9 and 10, therotor102 includes arotor core124, shown inFIG. 10, on ashaft126 that is mounted to themotor housing200 bybearings108, shown inFIG. 3, or the like, as discussed above. As seen inFIG. 10, therotor core124 may be advantageously mounted to theshaft126 through twoquick change connections128. Thequick change connections128 hold therotor core124 on theshaft126 yet allow therotor core124 to be quickly removed therefrom through the use of a quick change tool to allow, for example, easy and rapid replacement of therotor core124 orshaft126 if damaged or otherwise deemed unusable during use.
• The type ofquick change connections128 employed in themotor10 may be similar to various known quick change connection mechanisms and may include, for example, a circular component, bending and moving components, adjustable force amplifying components and interfacing components. Thequick change connections128 provide a removable anti-rotational force and anti-lateral movement force between therotor core124 and theshaft126 by applying multiple small movements that increase or decrease stress of flexible members, or interlocking distances between movable members associated with therotor core124 and theshaft126. Alternatively, thequick change connections128 may include threaded components that are located at different positions when thequick change connections128 provide anti-rotation force and the anti-lateral force versus when thequick change connections128 provide no force. Through the use ofquick change connections128, the present disclosure advantageously allows for therotor core124 to be connected and/or disconnected from theshaft126 without the need to apply heat to parts of themotor10.
• Referring toFIGS. 10 and 11, therotor core124 has a plurality of rotor bars130 attached to the exterior thereof. The rotor bars130 may be connected to the outer ring of therotor core124 through anend ring132 at each axial end of therotor core124. Theend ring132 may include a dovetail connection that slides on axially and advantageously allows therotor102 to be constructed axially shorter than other connection methods. For example, on an axially inner portion of eachend ring132 there is arecess136 formed therein that mates with acorresponding mating boss138 formed on therotor core124. The end rings132 and the dovetail connection with therotor core124 advantageously inhibits radial expansion during operation of themotor10 due to, for example, thermal or other forces. Thus, the dovetail connection improves the integrity and stability of therotor102 during operation. While this dovetail connection has been shown and described as theend ring132 having a recess and therotor core124 having a mating boss, it should be readily understood that, in accordance with principles of the present disclosure, the reverse may be true to form an alternative dovetail connection that provides the same advantages discussed above, i.e. therotor core124 may be formed with a recess or recesses and the end rings132 formed with a mating boss or mating bosses.
• As shown inFIG. 11, aheat sink134 may be mounted on a portion of eachend ring132 to help draw heat from therotor102 to a cooling path through the rotor discussed in greater detail below. Positioning theheat sink134 on the end rings132 increases a surface area of the heat producing components exposed to the cooling path, which improves heat removal efficiency for cooling air being moved through themotor10 during operation.
• As seen inFIG. 10, the rotor also includesadjustable deflector plates142, which may be moved axially in or out relative to therotor core124 along theirsupport screws144 to increase or decrease the size ofpassage146 between the outer edge of thedeflector plates142 and therotor core124, thereby controlling an airflow supply of cooling air that is passed through therotor core124. Thedeflector plates142 are configured so that theshaft126 may extend through an inner area of eachdeflector plate142. Thedeflector plates142 may have one or moreadditional air vents148 at an inner diameter of thedeflector plate142. Thedeflector plates142 may be moved to desired positions for controlling an airflow supply of cooling air to be passed through therotor core124 while simultaneously deflecting high velocity air onto the inner surface of the rotor end rings132 andheat sinks134 mounted thereon, thereby providing additional cooling to heat generating portions of therotor102. As should be understood by those skilled in the art, any exposed surface of therotor102 will benefit from the deflected air passing over said surface. Additionally, theadditional air vents148 also advantageously support heat removal by providing cooling air to pass along theshaft126 to stir up airflow near theshaft126 where thebearings108 generate heat.
• As shown inFIG. 3, therotor core124 may have a plurality of rotor vents150 formed therein extending from one axial end of therotor core124 to the other axial end of therotor core124. Alternatively, referring toFIGS. 10 and 11, the rotor vents150 may be formed aspassages152 extending in an axial direction of therotor core124 from one end to the other between struts orlegs154, shown inFIG. 11, supporting therotor core124 on theshaft126. As shown inFIG. 12, eachrotor vent150 has entry and/or exit holes156 at each axial end. The rotor vent holes156 may have a sharp, i.e. stamped approximately 90 degree, entrance or may advantageously have a shaped entrance to improve airflow therethrough. For example, the rotor vent holes156 may be shaped by a chamfered edge, as shown inFIG. 13, leading into and/or out of therotor vent150 to provide a smoother transition that reduces turbulent flow at the entrance. Although shown with a single chamfer, it should be readily understood that the transition may be formed with an increased number of chamfered edges to simulate a curved entrance, further smoothing the transition and reducing turbulent flow. Alternatively, as shown inFIG. 14, the rotor vent holes156 may be formed with a curved radius leading into and/or out of the rotor vents150 such that there are no discontinuities formed in the edge.Holes156 formed with the curved radius at the entrance/exit of therotor vent150 may provide an even smoother transition that minimizes turbulent flow.
• The rotor vents150 withholes156 formed as the entry and/or exits provide improved airflow during operation of themotor10. Theholes156 being formed with chamfered or sloped edges in therotor core124 advantageously minimizes turbulence of cooling air entering the rotor vents150 thereby reducing entrance and exit fluid drag.
• Referring toFIGS. 15 and 16A-16C, eachrotor vent150 may have a turbulator158 disposed therein. Theturbulators158 are irregular elongated metal sheets that, when disposed in rotor vents150, form multiple obstructions for airflow in the rotor vents150 that churn up cooling air within the rotor vents150 during operation. Thus, theturbulators158 increase turbulence of air flow within the rotor vents150 to improve heat removal from therotor core124 during operation.
• Therotor core124, shown inFIGS. 10-12, may be formed by a series of stacked laminations arranged adjacent to one another.FIG. 17 shows a singlesuch lamination160 of therotor core124, shown inFIGS. 10-12. Eachlamination160 includes a centrally located shaft opening162, shown inFIGS. 17 and 18, that is sized and shaped to appropriately receiveshaft126. Eachlamination160 has at least onekeyway164 formed in a periphery of theopening162 to allow the lamination to be stacked on a rotor shaft having a corresponding key that fits within thekeyway164. As shown inFIG. 17, eachlamination160 is provided with threekeyways164 spaced apart from each other evenly at 120 degree intervals. As discussed above, therotor core124 is formed by a series of stackedlaminations160 and theselaminations160 may have variations in weight distribution and/or density within eachlamination160. Therefore, providing eachlamination160 with the three evenly spacedkeyways164 allows for balancing of thelaminations160 during assembly of therotor core124 by allowing thelaminations160 to be rotated an interval equal to the angular degree spacing of thekeyways164, i.e. 120 degrees in theexemplary motor10 described above. As should be readily understood from the present disclosure, thelaminations160 may include one ormore keyways164 and the one ormore keyways164 may also be evenly spaced angularly apart from one another. Increasing the number ofkeyways164 provided in thelaminations160 offers more rotation options for balancing, but also, may incur more manufacturing costs for formation of thekeyways164 as well as weights and fillers used to fill theunused keyways164.
• Referring toFIGS. 12 and 18, therotor core124 may also have one ormore balance slugs166 disposed in one or more of the rotor vents150, as necessary, in order to further balance therotor core124. The balance slugs166 have a shape that conforms to the rotor vents150 so as not to come loose during operation of themotor10, shown inFIGS. 1A-1C. Also shown inFIG. 18, in the partial cutaway portion, the twounused keyways164 are filled for balancing purposes. The material used for the balance slugs166 and/or for filling theunused keyways164 may be selected from any suitable filling materials including, without limitation, metals, polymers, ceramics, hybrid compounds, or the like.
• The balance slugs166 may advantageously be disposed in rotor vents150 that are more closely located to an inner radius of therotor core124 than other rotor vents150. This may requiremore balance slugs166 to be used in order to properly balance therotor102, but may also provide an advantage as themotor10 heats up during operation because there will be less of a change in balance of therotor102 since the moments generated by the balance slugs166 on therotor102 will be located closer to thecentral axis106 when compared to other balancing techniques. Since a significant number of rotor vents150 may be formed in therotor102, the addition of the vent slugs166 to some of the rotor vents will not impair cooling of themotor10. Additionally, the balance slugs166 may advantageously be inserted into the rotor vents150 that will provide the least amount of cooling reduction so as to minimize a drop in cooling efficiency due to the addition of the vent slugs166. The use ofbalance slugs166 advantageously allows for balancing of therotor102 without the need to use fasteners to attach weights to therotor102 and/or the need to remove material from therotor102.
• Referring toFIGS. 19 and 20, theterminal box assembly300 may house various electronic andcontrol components302 for controlling themotor assembly100 and/orfan module assembly400 during operation and advantageously partitions the electronic andcontrol components302 in aseparate compartment304 away from both themotor assembly100 andfan module assembly400. Theterminal box assembly300 may include one ormore covers306 to provide access to the electronic andcontrol components302 housed therein and may advantageously employ gaskets at interfaces between the one ormore covers306 and the body of theterminal box assembly300 to protect the electronic andcontrol components302 housed therein from the contaminants such as moisture, dust and the like.
• With reference toFIGS. 1A-1C, 2A-2C and 21, thefan module assembly400 comprises afan housing402. Thefan module assembly400 is mounted to the top ofmotor housing200, as discussed above, with thefan housing402 being in fluid communication with theair outlet204 of themotor housing200 throughhousing openings404. Thefan module assembly400 may be removably attached to themotor housing200 bylatches406 to advantageously allow for relatively easy removal of thefan module400 from themotor housing200 for maintenance, repair and the like. Alternatively, thefan module assembly400 may be attached to themotor housing200 through any other securing mechanism, in either a removable or permanent manner, including, without limitation, nuts and bolts, welding, hooks, hand adjustable clamps, elastic members, holes with pegs, or the like as should be readily understood by those skilled in the art. Thefan module assembly400 includes at least oneblower408. As seen inFIGS. 1A-1C, thefan module assembly400 may be configured with eachinlet410 of eachblower408 fluidly connected to an area exterior of themotor10 and eachoutlet412 connected to thefan housing402 to blow cooling air into thefan housing402. Alternatively, as seen inFIGS. 2A-2C, theinlets410 of theblowers408 are fluidly connected to thefan housing402 and theoutlets412 of theblowers408 are fluidly connected with an area exterior of themotor10 to draw cooling air out of thefan housing402.
• Thelatches406 advantageously allow thefan module assembly400 to be quickly assembled or disassembled from themotor housing200 without the use of tools by actuating thelatches406 from a secured position to an unsecured position and vice versa. When thelatches406 are in the secured position, thefan module assembly400 is secured to themotor housing200 and when the latches are in the unsecured position, thefan module assembly400 may be removed from themotor housing200. Thus, by removing thefan module assembly400, access to themotor assembly100 is readily attainable through theair outlet204 of themotor housing200, both shown inFIG. 6, for maintenance and repair purposes or the like.
• In operation of themotor10, themotor assembly100 runs and is controlled in the same manner as any typically known motor including variable speed devices (i.e. VFDs). During operation, theblowers408 may be configured to use negative pressure to cool themotor assembly100 by pulling air out of themotor housing200, as shown inFIGS. 2A-2C. Specifically, air enters themotor housing200 through theair inlets202 of themotor housing200, passes through and cools themotor assembly100, passes into thefan housing402 through thehousing openings404 in the bottom thereof, passes into theblowers408 viablower inlets410 and is expelled from themotor10 through theblower outlets412. Additionally, during operation, thefan housing402 provides noise reduction benefits by dampening sounds caused by operation of themotor10. Alternatively, as shown inFIGS. 1A-1C, theblowers408 may be configured to use positive pressure to cool themotor assembly100 by pushing air into themotor housing200. Specifically, air enters thefan module assembly400 via theblowers408, passes into thefan housing402, passes through thehousing openings404 and into themotor housing200, passes through and cools themotor assembly100 and is expelled from themotor10 throughair inlets202. This configuration is an instance where, as discussed above, theair inlets202 serve as an outlet for air moving through themotor housing200.
• Themotor10 has at least three separate cooling paths that air passes through to cool themotor10. Thefirst cooling path500, shown inFIGS. 10 and 22-24, is through the inside of therotor102, i.e. through therotor core124 by passing around an outer edge of thedeflector plate142 and/or throughair vents148, then throughvent holes156 and rotor vents150. The cooling air then passes to theair outlet204 where the cooling air exits themotor housing200 into thefan housing402 through thehousing openings404. Thesecond cooling path502 andthird cooling path504 are shown inFIG. 5. Thesecond cooling path502 is between thestator104 and therotor102. Specifically, the cooling air passes through the inside of thestator104 through thestator channels120 in thestator slots112 and around the exterior of therotor102. Thethird cooling path504, also shown inFIG. 5, is around the outside of thestator104 and within themotor housing200. While the coolingpaths500,502,504 are illustrated with arrows pointing in a given direction, it should be understood that depending on the configuration of thefan module assembly400 and desired operation of themotor10, cooling air may travel in thesame cooling paths500,502,504 but move in the opposite direction than is shown in any of the Figures. For example,FIG. 25 shows arrows representing air flow during operation of the motor shown inFIG. 1A. The direction of the air flow would be in the opposite direction than all of the arrows shown inFIG. 25 if thefan module assembly400 were configured to pull air through themotor housing200 as discussed above.
• The present disclosure advantageously provides amotor10 with improved cooling of not only therotor102, but also itsstator104 by increasing a quantity and/or rate of air that contacts thestator104 during operation, and by providingstator channels120 in close proximity to heat generating components of thestator104. For example, since thecoils116 are disposed in the vicinity of thestator channels120, thestator channels120 are able to provide an increased amount of cooling air near thecoils116, thereby increasing efficacy of available cooling air flow.
• The present disclosure advantageously provides a negative pressure cooling system and method that minimizes acoustic noise usually generated at blower inlets at the expense of reduced air mass flow and mass flow sensitivity to motor outlet air temperature. While negative pressure pulling air through themotor10 may be advantageous for noise reduction purposes, one skilled in the art should readily understand that, in accordance with principles of the present disclosure, theblowers408 may be configured to instead use positive pressure to push air through themotor10, as shown inFIGS. 1A-1C, which may provide superior heat removal.
• Using negative pressure to cool themotor10 by generating a vacuum that pulls air out of themotor housing200, as opposed to using positive pressure to pump air into themotor housing200, advantageously provides for more efficient cooling having better flow characteristics. Additionally, the implementation of negative pressure advantageously provides a much quieter cooling system. Further, in accordance with principles of the present disclosure, the superior heat removal aspects of amotor10 also allow theblowers408 of thefan module assembly400 to operate at lower speeds and, thus, lower air velocity and/or quantities, which thereby provides further noise dampening advantages.
• The present disclosure advantageously describes amotor10 that can be suitably modified for a wide range of sizes and/or motor capacities due to the improved airflow, cooling and stability discussed above. Thus, embodiments in accordance with the present disclosure are advantageously scalable in size to achieve a variety of different applications. The various structural and cooling aspects discussed above advantageously allow themotor10 to be provided at a much smaller size and weight as compared to comparably powered devices by trading-off, for example, efficiency for size, weight and material. High power density motors are advantageous for applications where size and/or weight requirements of the motor must be kept low, but power output requirements of the motor are high.
• While the present disclosure has been illustrated and described with respect to particular embodiments thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure. For example, while the present disclosure shows and describes an AC induction motor well-suited for high power density motor applications, it should be readily understood that principles of the present disclosure can be applied to other motor applications such as DC motor applications and also applications where, for example, space constraints are not a significant consideration.

Claims (27)

What is claimed is:

1. A motor comprising:

a stator; and

a rotor rotatable within the stator about a central axis, the rotor comprising:

a shaft having a key feature formed along at least a portion of an axial length thereof; and

a rotor core comprising a plurality of stacked laminations, each lamination of the plurality of stacked laminations including a central opening for passage of the shaft therethrough, the central opening having at least two keyways formed therein with a shape corresponding to the at least one key feature of the shaft, the at least two keyways being evenly spaced angularly about the central axis;

wherein each lamination is arranged with one of the at least two keyways accommodating the key feature of the shaft.

2. The motor according toclaim 1, wherein the rotor core further comprises:

a plurality of rotor bars extending parallel to the central axis and disposed at an outer surface of the plurality of laminations; and

two end rings positioned at opposing axial ends of the rotor core, the two end rings being connected to the plurality of rotor bars;

wherein each end ring includes a dovetail connection with the rotor core.

3. The motor according toclaim 2, wherein the dovetail connection includes one or more recesses formed in the end ring and configured to mate with a corresponding one or more mating bosses of the rotor core.

4. The motor according toclaim 2, wherein the dovetail connection includes one or more mating bosses formed on the end ring and configured to mate with one or more corresponding recesses of the rotor core.

5. The motor according toclaim 1, wherein the rotor core further comprises:

a plurality of rotor bars extending parallel to the central axis and disposed at an outer surface of the plurality of laminations; and

two end rings positioned at opposing axial ends of the rotor core, the two end rings being connected to the plurality of rotor bars;

the motor further comprising a heat sink connected to one or more of the end rings or rotor bars of the rotor.

6. The motor according toclaim 1, wherein the rotor core includes a plurality of rotor vents that are formed by holes in the laminations distributed about the central axis in relation to the at least two keyways.

7. The motor according toclaim 6, further comprising at least one balance slug positionable in rotor vents of the plurality of rotor vents for balancing the rotor.

8. The motor according toclaim 6, wherein at least one rotor vent of the plurality of rotor vents has an entrance or exit hole formed with at least one chamfered edge.

9. The motor according toclaim 6, wherein at least one rotor vent of the plurality of rotor vents has an entrance or exit hole formed with a curved edge.

10. The motor according toclaim 6, wherein a turbulator is disposed in at least one rotor vent.

11. The motor according toclaim 1, further comprising an adjustable deflector plate attached to an axial end of the rotor core and configured to move axially in and out relative to the rotor core.

12. The motor according toclaim 11, wherein movement of the adjustable deflector plate changes a size of a flow passage between the adjustable deflector plate and the axial end of the rotor core.

13. The motor according toclaim 11, wherein the adjustable deflector plate has at least one air vent formed at an inner portion thereof adjacent the shaft.

14. The motor according toclaim 1, wherein the rotor further comprises at least one quick-change connection releasably coupling the rotor core to the shaft.

15. The motor according toclaim 1, wherein the motor is an AC induction motor.

16. A motor comprising:

a stator; and

a rotor rotatable within the stator about a central axis, the rotor comprising:

a shaft; and

a rotor core comprising a plurality of rotor bars extending parallel to the central axis, and two end rings positioned at opposing axial ends of the rotor core, the two end rings being connected to the plurality of rotor bars;

wherein each end ring includes a dovetail connection with the rotor core.

17. The motor according toclaim 16, wherein the dovetail connection includes one or more recesses formed in the end ring and configured to mate with a corresponding one or more mating bosses of the rotor core.

18. The motor according toclaim 16, wherein the dovetail connection includes one or more mating bosses formed on the end ring and configured to mate with one or more corresponding recesses of the rotor core.

19. A motor comprising:

a stator;

a rotor rotatable within the stator about a central axis, the rotor comprising:

a shaft; and

a rotor core comprising a plurality of rotor bars extending parallel to the central axis, and two end rings positioned at opposing axial ends of the rotor core and connected to the plurality of rotor bars; and

a heat sink connected to one or more of the end rings or rotor bars of the rotor.

20. A motor comprising:

a stator; and

a rotor rotatable within the stator about a central axis, the rotor comprising:

a shaft; and

a rotor core, the rotor core including a plurality of rotor vents that are formed by holes extending parallel to the central axis and distributed about the central axis.

21. The motor according toclaim 20, further comprising at least one balance slug positionable in rotor vents of the plurality of rotor vents for balancing the rotor.

22. The motor according toclaim 20, wherein at least one rotor vent of the plurality of rotor vents has an entrance or exit hole formed with at least one chamfered edge.

23. The motor according toclaim 20, wherein at least one rotor vent of the plurality of rotor vents has an entrance or exit hole formed with a curved edge.

24. The motor according toclaim 20, wherein a turbulator is disposed in at least one rotor vent.

25. A motor comprising:

a stator;

a rotor rotatable within the stator about a central axis, the rotor comprising:

a shaft; and

a rotor core, the rotor core including a plurality of rotor vents extending through the rotor core parallel to the central axis and distributed around the shaft; and

an adjustable deflector plate attached to an axial end of the rotor core and configured to move axially in and out relative to the rotor core.

26. The motor according toclaim 25, wherein movement of the adjustable deflector plate changes a size of a flow passage between the adjustable deflector plate and the axial end of the rotor core.

27. The motor according toclaim 25, wherein the adjustable deflector plate has at least one air vent formed at an inner portion thereof adjacent the shaft.

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