SYSTEM AND METHOD OF DISCHARGING ROTOR VOLTAGE

Systems and method to control rotor voltage of a liquid cooled motor are provided. A system can include a rotor, a shaft, and a ring. The ring can be disposed on the shaft. The ring can include a first lip in contact with an inner surface of the rotor and a second lip in contact with the inner surface of the rotor and a cooling liquid. The first lip can provide an electrical path to discharge a voltage from the rotor. The second lip can provide a seal between the first lip and the cooling liquid.

INTRODUCTION

A vehicle, such as an electric vehicle, can be powered by batteries. The vehicle can include a motor to drive the vehicle based on power provided by the batteries.

SUMMARY

An aspect of this disclosure is generally directed to techniques for discharging or grounding a rotor voltage. In an electric motor, torque generated by a rotor can create an internal voltage. The internal rotor voltage can build up over time and eventually discharge. The internal rotor voltage can discharge through metal components of the motor (e.g., bearings, splines, or gears) degrading the components. This component degradation can lead to degradation in performance of the electric motor, and increase noise, vibration, and harshness (NVH). Discharging rotor voltage or grounding a rotor in a liquid or oil cooled motor can include technical challenges. For example, components that contact the rotor to ground the rotor may not properly provide a low resistance path to ground if an oil film develops between the grounding components and the rotating rotor. To solve these and other technical problems, the present solution can include a grounding ring that grounds the rotor and prevents the internal rotor voltage from building up and discharging. The ring can be disposed on a shaft that the rotor rotates around. The ring can include lips or wipers that make an electrical contact with an inner surface of the rotor while the rotor rotates. The ring can include multiple lips. These lips can be stacked along a longitudinal axis of the rotor and the shaft. At least one outer lip can provide a seal to limit or prevent oil from coming into contact with at least one inner lip. The outer lips can prevent a buildup of oil on the inner lips which may ground the rotor. By preventing a buildup in oil, the outer lips can prevent an increase in resistance to the electrical or grounding path that the inner lip provides.

At least one aspect is directed to a system to control rotor voltage in a motor. The system can include a rotor, a shaft, and a ring. The ring can be disposed on the shaft. The ring can include a first lip in contact with an inner surface of the rotor and a second lip in contact with the inner surface of the rotor and a cooling liquid. The first lip can provide an electrical path to discharge a voltage from the rotor. The second lip can provide a seal between the first lip and the cooling liquid.

At least one aspect is directed to an apparatus. The apparatus can include a body with a cylindrical shape disposed on a shaft within a rotor of a motor. The apparatus can include a first lip in contact with an inner surface of the rotor. The apparatus can include a second lip in contact with the inner surface of the rotor and a cooling liquid. The first lip can provide an electrical path to discharge a voltage from the rotor. The second lip can provide a seal between the first lip and the cooling liquid.

At least one aspect is directed to a method. The method can include disposing a ring around a shaft. The method can include inserting the shaft into a cavity of a rotor. The method can include discharging a voltage from the rotor by a first lip of the ring in contact with an inner surface of the rotor, the first lip providing an electrical path to discharge the voltage. The method can include providing a seal between the first lip and a cooling liquid with a second lip in contact with the inner surface of the rotor.

DETAILED DESCRIPTION

Following below are more detailed descriptions of various concepts related to, and implementations of, methods, apparatuses, and systems for discharging voltage of a rotor of a motor, such as a motor of an electric vehicle.

This disclosure is generally directed to controlling (e.g., discharging) voltage of a rotor in wet-cooled motor, including for example techniques for discharging rotor voltage or grounding the rotor in an oil-cooled electric motor. In an electric driveline, torque generated by a rotor can create an internal rotor voltage. As used herein, rotor voltage or voltage of a rotor can mean a voltage generated by torque of a rotor. If a ground path resistance in the motor is too high (e.g., 5V, 10V, 15V, 20V, 50V, or higher), the internal rotor voltage can build up over time and eventually discharge. The internal rotor voltage may discharge through metal components of the motor (bearings, splines, or gears) to a ground. When the voltage reaches or exceeds a threshold, the discharge may, over time, degrade the performance of the electric motor, or cause or increase NVH.

This technical solution provides a wet-cooled environment (e.g., oil-cooled) for the electric motor that includes a ring that grounds or discharges voltage from the rotor. By grounding or discharging voltage from the rotor, this technical solution can prevent or mitigate the likelihood that the internal rotor voltage reaches or exceeds a threshold voltage. The ring can be disposed on a shaft around which the rotor rotates. The ring can include lips or wipers that make an electrical contact with an inner surface of the rotor while the rotor rotates. The ring can include multiple lips. These lips can be stacked along a longitudinal axis of the rotor and the shaft. At least one outer lip can provide a seal to limit or prevent oil from coming into contact with at least one inner lip. The outer lips can prevent a build-up of oil on the inner lips to prevent an increase in resistance to the electrical or grounding path that the inner lip provides.

Referring toFIG.1, among others, a motor100including a ring115disposed on a shaft105that controls (e.g., grounds or discharges) voltage from a rotor110is shown.FIG.1depicts a cross-sectional view of the motor100. The rotor110can be a rotor110of an apparatus100, such as a motor. The motor100can be a motor of an electric vehicle, such as an alternating current (AC) motor, a direct current motor (DC) motor, an electric driveline, or any other type of motor or drive component. The motor100can be a synchronous or asynchronous motor. The motor100can be powered by a battery pack, battery module, or battery cell of an electric vehicle. The motor100can operate to generate torque to drive the vehicle, e.g., cause the vehicle to drive forward, cause the vehicle to drive in reverse, or cause the vehicle to turn. The motor100can operate to perform a regenerative braking to use vehicle momentum to generate current to charge the battery pack, battery module, or battery of the vehicle. While the motor100is described as an electric motor of a vehicle, the apparatus100can be a motor, a clutch, a generator, a system, or any other component with a rotating rotor110.

The motor100can include at least one bearing160. The bearing160can include an inner diameter and an outer diameter. The bearing160can be a rolling bearing, a ball bearing, a plain bearing, a magnetic bearing, a fluid bearing, or any other type of bearing that can rotate around a longitudinal axis. The bearing160can couple to the rotor110and fix the rotor110to the motor100. The rotor110can rotate around a longitudinal axis125via the bearings160. For example, the rotor110can be inserted into an opening of the bearing160and make contact with an inner surface of the bearing160. Rotation of the rotor110can cause an inner disc of the bearing160to spin, while an outer disc may be fixed to a wall of the motor100and may not spin relative to the rotation of the rotor110.

The rotor110may include at least one magnet. The rotor110may not include any magnets. The motor100may be an induction motor or a permanent magnet based motor. In such examples, the magnets can be or include ferrite magnets, aluminum nickel cobalt magnets, samarium cobalt magnets, or neodymium iron born magnets. The motor100can include at least one stator130. The stator130can surround the rotor110. The stator130can be fixed or be stationary and may not rotate within the motor100. The stator130can create a magnetic field around the rotor110. For example, the stator130can create a magnetic field, based on power received from a battery pack, a battery module, or a battery cell. The rotor110can spin around a longitudinal axis125to align with the magnetic field created by the stator130. For example, based on the magnets of the rotor110, the rotor110can rotate to align with the magnetic field of the stator130. The motor100can cause the magnetic field to rotate around the longitudinal axis125causing the rotor110to spin and generate torque to drive an axle of the motor100. The axle can drive at least one wheel or other tractive component of the vehicle. For example, the axle can be coupled with a wheel or drive line to cause the wheel to spin.

The axle can, in some cases, rotate to cause the rotor110to rotate. The rotation of the rotor110can induce a magnetic field in the stator130. For example, the motor100can perform regenerative braking causing momentum of the wheels of a vehicle to spin the rotor110and induce a magnetic field in the stator130causing current to flow in the stator130. This energy can be stored in batteries of the vehicle. If the apparatus100is a generator, the axle can be driven by a windmill, or a turbine. The axle can drive the rotor110causing a magnetic field to be induced in the stator130.

The rotor110can include a cavity135. The cavity135can be a cylindrical shaped cavity with a circular inner surface140. The inner surface140can be circular or oval shaped. The cavity135can include a longitudinal axis125. A longitudinal axis125of the cavity135can be aligned with the longitudinal axis125of the rotor110. At least one shaft105can extend through, or at least partially into, the cavity135of the rotor110. The rotor110can spin or rotate around the shaft105. The shaft105can be a pole, a rod, an axle, an inner bore rotor shaft. The shaft105can be fixed or stationary and may not move or rotate within the motor100. The shaft105can be a cylindrical shaped shaft105. An outer surface145of the shaft105can be circular or oval shaped. The outer surface145of the shaft105and have a diameter or radius less than a diameter or radius of the cavity135of the rotor110such that the shaft105can fit within the rotor110or so that the rotor110can rotate around the shaft105without contacting the shaft105. The shaft105can extend from a first end or wall of an enclosure, case, or housing of the motor100into the cavity135of the rotor110. The shaft105can extend partially into or fully across the rotor110along the longitudinal axis125.

The shaft105can include at least one grounding ring, ring, cylinder, band, halo, or disk115. The ring115can be a cylindrical shaped component that is coupled, fixed, fixedly coupled, connected, or joined to the outer surface145of the shaft105. The ring115can have an inner surface or side150that extends at least partially around the outer surface145of the shaft105. The diameter or radius of the inner surface of the ring115can be the same as, slightly smaller, or slightly larger, than the diameter or radius of the outer surface145of the shaft105. The ring115can be coupled to, connect with, contact with, or touch to, the shaft105through a frictional force between the inner side150of the ring115and the outer surface145of the shaft105. The inner side150of the ring115can contact the outer surface145of the shaft105. The ring115can have a diameter slightly (e.g., 1%, 2%, 3%, 4%, 5%, 10% or other percentage that facilitates disposing the ring115on the shaft105to provide a seal or discharge voltage from the rotor) smaller than a diameter of the shaft105and therefore the ring115can exert a spring force against the surface145of the shaft105, frictionally fixing the ring115to the shaft105. The ring115can be fixed to the shaft105with an adhesive, such as a conductive adhesive. The adhesive can be disposed between the side150of the ring115and the surface145of the shaft105and can bind, couple, or fix the ring115to the shaft105. At least one washer, nut, connector, bolt, screw, or nail can fix the ring115to the shaft105.

The ring115can be or include a flexible material. The material of the ring115can apply a force on the outer surface145of the shaft105and fixes the ring115to the shaft105. The ring115can be or include a conductive material. The material can be or include a polymer (e.g., an intrinsically conducting polymer (ICP) such as polyacetylene, polyphenylene vinylene, polypyrrole, polythiophene, polyaniline, or polyphenylene sulfide), metal (e.g., copper, iron, gold, aluminum, silver), a metal spring, a conductive graphite, a conductive elastomer, a conductive carbon fiber, or other material. The material can further be non-conductive or include non-conductive elements such as plastic, rubber, or any other insulating material. The ring115can be electrically coupled, electrically connected, or in electrical contact with the shaft105. For example, the side150of the ring115can touch the surface145of the shaft105electrically coupling or connecting the ring115and the shaft105.

The ring115can include a body170. The body170of the ring115can have a shape. The shape can be cylindrical. The body170can be a disc, a ring shape, a cylinder shape, or a hollow cylinder shape. The body170can extend radially from the longitudinal axis125of the ring115from the side150to the surface155. The body170can include openings for the shaft105to extend through. The body170can include an inner cavity defined by the side150. The inner cavity can have a shape. The shape can be cylindrical. The shape can be an octagonal prism. The shape can be a decagonal prism.

The ring115can include at least one contact surface, fin, edge, protrusion, component, wiper lip, sealing lip, or lip120. The lips120can contact an inner bore rotor shaft105. The ring115can include at least one lip120. The ring115can include multiple rings115evenly or unevenly spaced along the longitudinal axis125. At least one lip120can extend from the body170of the ring115. At least one lip120can extend from an outer surface155of the ring115away from the outer surface155towards the surface140of the cavity135. The lips120can contact the rotor110or the surface140of the rotor110. The lips120can contact the rotor110or the surface140to ground the rotor110. The lips120can make an electrical contact with the rotor110or the surface140of the rotor110. The lips120can be electrically coupled with the rotor110or the surface140of the rotor110. The lips120can be electrically connected to rotor110or the surface140of the rotor110. The ring115can be a single component formed, molded, or cast from a single material or multiple materials. The ring115can be or include multiple pieces, parts, or components, such as an assembly of pieces. For example, the body170of the ring can be one piece while the lips120can each be separate pieces that fix, couple, or join to the body170via an adhesive, glue, a weld, a plastic, or any other connector.

The ring115can ground the rotor110. The ring115can discharge a voltage generated within the motor100. The ring115can discharge a voltage created by the rotor110. For example, the ring115can provide a ground path, between the rotor110and a ground and thus discharge a voltage of the rotor110. The ring115can electrically couple the rotor110to the shaft105to ground the rotor110. For example, the shaft105can be electrically coupled to a frame of the vehicle thereby grounding the ring115and the rotor110or providing an electrical path from the rotor110to a ground. The electrical path can include the ring115, one or more conductors, the shaft105, wires, or other conducting components that couple the rotor110to a neutral or ground component, e.g., a vehicle frame or chassis. The shaft105can be electrically connected or coupled with a housing of the motor100. In other examples, the ring115may be grounded via a conductive path separate from the material forming the shaft105(e.g., a conductive wire or path internal to the shaft105connected to the ring115). The motor100can be installed on a frame of a vehicle and electrically coupled, connected, or joined to the frame. The frame can be or provide a ground for the vehicle. By electrically coupling the rotor110to the ring115, the ring to the shaft105, the shaft to the housing of the motor100, and the housing of the motor100to the frame of the vehicle, the rotor110can be grounded. At least one conductive element, component, wire, trace, or other element can electrically ground the ring115or the shaft105to ground the rotor110. Grounding or coupling a component to an electrical path, e.g., electrically coupling the rotor110to a ground, can include electrically coupling the component to another component that is electrically neutral or negative.

The lips120of the ring115can include inner lips120and outer lips120. The outer lips120, for example the lips120on the ends of the ring115, can prevent, limit, or reduce an amount of a liquid (e.g., a cooling liquid) within the motor100from contacting the inner lips120. For example, the outer lips120can keep the inner lips120free or at least partially free of the liquid. For example, the outer lips120can keep the inner lips120dry or at least partially dry of the liquid. The liquid can be a refrigerant or oil that cools internal components (e.g., the stator130, the rotor110, bearings160, or any other heat generating component) of the motor100. The oil can be or include a refrigerant oil, e.g., a mineral oil or a synthetic oil. The synthetic oil could be alkylbenzene, polyolester, polyalkylene glycol, polyvinyl ether. The oil can be pumped into or out of the motor100. The oil can absorb heat generated by the rotating components of the motor100, e.g., heat generated by the rotation of the rotor110, the oil can be pumped out of the motor100to transfer the heat away from the motor and keep the internal components of the motor100cool. Because the motor100is oil cooled, the motor100can have better thermal performance and thus reduce any power limitations due to overheating of components.

Referring toFIG.2, among others, the ring115for grounding the rotor110or discharging rotor voltage is shown.FIG.2depicts an isometric view of ring115. The ring115can be a cylindrical shaped component that fits around the shaft105. The ring115can include a first opening215and a second opening220. The openings215and220can be circular, oval shaped, curved, or a free form shape. The ring115can include an inner circumference, boundary, or area210and an outer circumference boundary, or area205. The inner circumference210can define the inner surface155. The outer circumference205of the shaft105can be the same size, slightly smaller, than an inner circumference of the shaft105such that the ring115can frictionally couple with the shaft105. The lips120can extend away from the outer surface155or the longitudinal axis125. The lips120can bend away from the opening215towards the opening220. For example, the lips120can bend towards a wall of the motor100and away from the rotor110. Because the lips120can be angled away from the rotor110, when the ring115is inserted into the cavity135of the rotor110, the lips120may not be bent or twisted and thus the lips120may not lose any integrity and apply a force or pressure against the surface140of the cavity135.

The ring115can have a length225, an inner width230, and an outer width235. The length225can be the distance that the ring115extends from end to end along the longitudinal axis125. For example, the distance225can be a length between the first opening215and the second opening220. The distance225can be nine to twelve millimeters long. The distance225can be five to fifteen millimeters long. The distance225can be less than five millimeters long. The distance225can be greater than fifteen millimeters long. The inner width230can be five to ten millimeters long. The inner width230can be three to twelve millimeters long. The inner width230can be less than three millimeters long. The inner width230can be greater than twelve millimeters long. The outer width235can extend between edges of the lips120. For example, the outer width235can be a diameter of the outer edge of the lips120. The outer width235can be eight to eleven millimeters wide. The outer width235can be five to fourteen millimeters wide. The outer width235can be less than five millimeters long. The outer width235can be greater than fourteen millimeters wide.

Referring toFIG.3, among others, a ring115for grounding a rotor110or coupling the rotor110to an electrical path to ground is shown.FIG.3depicts a cross-sectional view of the ring115. The ring115can include four lips120. While the ring115is shown to include four lips120, the ring115can include any number of lips. For example, the ring115can include two lips120, e.g., a first lip120ato limit liquid from coming into contact with a second lip120b. As another example, the ring115can include three lips120, a first lip120aand a third lip120con either side of a second lip120bthat limit liquid from coming into contact with the second lip120b. The ring115can include a fourth lip120dthat limits liquid from contacting the second lip120band the third lip120c. The ring115can include an odd or even number of lips120. The lips120inFIG.3are shown to be equally spaced from each other. However, the lips120can be unequally spaced along the longitudinal axis125. For example, the lips120can be separated from each other by one, two, three, or any number of different distances.

A lip120can be positioned on the ring115a distance from an end165of the shaft105. The end165is described in further detail, for example, atFIG.7. The end165can be a point where the shaft105meets a wall of the motor100. The lips120can each be positioned on the ring115along the longitudinal axis125a distance from the end165of the shaft105. The first lip120acan be positioned a first distance D1from the shaft end165. The second lip120bcan be positioned a second distance D2from the shaft end165. The second distance D2can be greater than the first distance D1. However, the second distance D2can be less than a third distance D3and less than a fourth distance D4. A third lip120ccan be positioned a third distance D3from the shaft end165. The third distance D3can be greater than the first distance D1and greater than the second distance D2. However, the third distance D3can be less than a fourth distance D4. The fourth lip120dcan be positioned a fourth distance D4from the shaft end165. The fourth distance D4can be greater than the first distance D1, the second distance D2, and the third distance D3.

A lip120can include a first side315and a second side320. The first side315and the second side320can extend from the outer side or surface155of the ring115. The first side315and the second side320can extend radially away from the longitudinal axis125of the ring115. The first side315can be angled towards the shaft end165. For example, the first side315can extend from the surface155at an angle325. The angle325can be an acute angle. The angle325can be less than ninety degrees. The angle325can be between seventy degrees and eighty degrees. The angle325can be between sixty-five and eighty-five degrees. The angle325can be between sixty degrees and ninety degrees. The angle325can be less than sixty-fix degrees. The angle325can be equal to or greater than ninety degrees. The second side320can form an angle330with the surface155. The angle330can be greater than ninety degrees. The angle330can be one hundred to one hundred and ten degrees. The angle330can be ninety five to one hundred and fifteen degrees. The angle330can be ninety to one hundred and twenty degrees. The angle330can be less than ninety degrees. The angle330can be greater than one hundred and twenty degrees.

The first side315and the second side320can meet at an area, boundary, portion, section, or edge310. The edge310can be a single sharp or curved edge where the first side315and the second side320join together. The edge310can have a round, rounded, curved, or circular contour. The edge310can be a flat edge or curved edge310. The edge310, the first side320, or the second side315can make contact with the surface140of the rotor110and electrically couple with the rotor110via the contact. In some cases, because the lip120may be angled towards the shaft end165only the second side320but not the first side315are in contact with the surface140of the cavity135of the rotor110. In some cases, because the lip120may be angled towards the shaft end165only the second side320and the edge310but not the first side315are in contact with the surface140of the cavity135of the rotor110.

The first side315can extend a distance less than the second side320extends. For example, the first side315and the second side320can both extend from the surface155of the body170. However, because the lip120may be angled towards the end165of the shaft105, the first side315can extend a first distance to the edge310which is less than a second distance that the second side320extends from the surface155to the edge310. In some cases, the total surface area of the first side315can be less than a total surface area of the surface320.

Referring toFIG.4, among others, the ring115including outer lips120forming a seal is shown.FIG.4depicts a cross-sectional view of a portion of the ring115and a portion of the rotor110. The lips120of the ring115can be in contact with, coupled to, or touching the surface140of the rotor110. The lips120can apply a force against the surface145of the rotor110. The surface145of the rotor110can apply a force against the surface140. For example, the diameter205of the ring may be greater than an internal diameter of the cavity135of the rotor110. The lips120can resist bending downward, applying a force equal and opposite to the force applied by surface140of the rotor110.

The forces applied between the surface140of the rotor and the lips120can cause a seal to form between the lips120and the surface140of the rotor110. For example, a seal can form between the edges310of the lips120and the surface140of the rotor110. The outer lips120can form a seal to prevent a fluid or liquid405from coming into contact with the inner lips120. For example, the motor100can be filled with the liquid405to cool internal components within the motor100that generate heat. For example, the liquid405can be a coolant, a refrigerant, or an oil. The oil can be or include a refrigerant oil, e.g., a mineral oil or a synthetic oil. The synthetic oil could be alkylbenzene, polyolester, polyalkylene glycol, polyvinyl ether. The liquid405may not be conductive, or may have a high resistance.

To prevent the liquid405from entering spaces between the inner lips120and the surface140, the outer lips120can prevent or limit the liquid405from coming into the spaces between the lips120. This can prevent the liquid from increasing the resistance between the surface140and the inner lips120. For example, the inner lips120can be fully isolated or partially isolated from the liquid405of the motor100via the outer lips120. For example, the spaces between the lips120can be free from the liquid405, or at least partially free from the liquid405. For example, there may be less liquid in the spaces between the lips120than in the rest of the motor100. For example, there may be less liquid in the spaces between the lips120than on an outer side of the outer lips120.

The inner and outer lips120can be formed from different materials. The materials that form the inner and outer lips120can be the same as or different from the material of the body170of the ring115. For example, the inner lips120can be formed from a conductive material or a low resistance material while the outer lips120can be formed from a non-conductive or high resistance material. For example, the inner lips120can be formed from a material to form an electrical connection with the rotor110while the outer lips120can be formed from a different material (e.g., an insulator) to create a seal with the surface140of the rotor110to prevent the liquid405from contacting the inner lips120. For example, the outer lips120can be formed from a rubber, a flexible plastic, a flexible polymer, or other material that can provide a seal or act as an insulator. The inner lips120can be formed from a conductive metal, a polymer, or any other conductive material.

Referring toFIG.5, among others, a lip120of a ring115for grounding the rotor110or coupling the rotor110to an electrical path to ground is shown.FIG.5depicts an isometric view of a lip120of the ring115. The first side315and the second side320can be curved surfaces, sides, boundaries, or sections of the lip120. The first side315can extend from a boundary, edge, a circumference, a circumferential boundary, or section505to the edge310. The boundary505can be a circle or circular boundary centered on the longitudinal axis125. The second side320can extend from a boundary, edge, or section510to the edge310. The boundary510can be a circle or circular boundary centered on the longitudinal axis125. The boundary510can be a boundary, edge, a circumference, a circumferential boundary, or a section. The edge310can be between the boundary505and the boundary510. The boundary505can extend about a first point on the longitudinal axis125. The edge310can extend about a second point of the longitudinal axis125. The boundary510can extend about a third point on the longitudinal axis. The second point can be positioned between the first point and the second point. The edge310can be positioned at a point on the longitudinal axis125between a first point on the longitudinal axis125that the boundary505is centered on and a second point on the longitudinal axis125that the boundary510is centered on.

The surfaces315and320can be flat (e.g., as shown inFIG.3) or curved (e.g., as shown inFIG.5). The lip120can extend around the entire outer side155of the ring115. The lip120can extend around only a portion of the outer side155of the ring115. Furthermore, the edge310can extend around the entire outer side155of the ring. The edge310can extend around the only a portion of the outer side155of the ring. The edge310can be a circular, curved, or circumferential edge. The edge310can extend around the entire outer side155of the ring115. The edge can extend around only a portion of the outer side155.

The lip120can have a width515. The width515can be a distance between the boundary505and the boundary510. For example, the width515can be a distance between the points or circumferential boundaries where the first side315and the second side320join to the body170. The width515can be between five and ten millimeters wide. The width515can be between two and thirteen millimeters wide. The width515can be less than two millimeters wide. The width515can be greater than thirteen millimeters wide.

Referring toFIG.6, among others, the motor100including a channel610that provides liquid to the motor100to cool the motor100.FIG.6depicts a cross-sectional view of the motor100. The motor100can include a case, enclosure, shell, or housing605. The motor100can include the channel610. The housing605can include the channel610. The channel610can be embedded in at least one wall of the housing605or can be formed through at least one pipe, connector, channel, fitting, or hose. The channel610can deliver oil or another liquid to the motor100. For example, shaft105can extend from a wall or side of the housing605. The channel610can run through the wall or side of the housing605and extend into the shaft105. The channel610can extend through the shaft105. The rotor110, the stator130, housings605, and bearings160to locate and support the motor100in a drivetrain.

The oil can move, transport, run, or flow through the channel610into the shaft105and into the cavity135of the rotor110. For example, the oil can flow through the channel610, through the shaft105, and out through an opening of an end620of the shaft105into the cavity135of the rotor110. The oil can lubricate or cool and rotor110. Furthermore, the oil can lubricate or cool the entire inner cavity615of the motor. For example, the oil can coat or cover the stator130or any other component in the inner cavity615. While the oil can contact, coat, or touch components in the inner cavity615, at least one lip120of the ring115can be free, or at least partially free, of the oil. At least one lip120of the ring115can limit the amount of oil that coats, contacts, or touches at least one other lip120of the ring115. By limiting the amount of oil that touches the lips120, the lips120can make a reliable electrical contact with the rotor110and ground the rotor110.

Referring toFIG.7, among others, a motor assembly where a shaft105including a ring115is inserted into a rotor110is shown.FIG.7depicts a cross-sectional view of the shaft105and the rotor110. During an assembly or manufacturing process of the motor100, a manufacturing machine, apparatus, robotic assembly, user, technical, or person can assemble the motor100. The housing605, or a portion of the housing605, can be manufactured assembled or built to include the shaft105. The ring can be placed onto the shaft105. The ring115can be slid, moved, or positioned onto the shaft105from an end620to the final position of the ring115on the shaft105. The shaft105can be inserted into the cavity135of the rotor110. The shaft105can be inserted into the cavity135of the rotor110after the ring115is disposed onto the shaft105.

The shaft105can be inserted into the cavity135through an opening of an end705of the rotor110. The shaft105can be inserted into the cavity135to an end710of the cavity135. Because the lips120of the ring115are bent away from the end705(or towards the end165of the shaft105), when the shaft105is inserted into the cavity135, the lips120may not lose any integrity, bend, break, or snap. The lips120may bend further towards the end165or further away from the end705.

FIG.8depicts an example cross-sectional view800of an electric vehicle805installed with at least one battery pack810. Electric vehicles805can include electric trucks, electric sport utility vehicles (SUVs), electric delivery vans, electric automobiles, electric cars, electric motorcycles, electric scooters, electric passenger vehicles, electric passenger or commercial trucks, hybrid vehicles, or other vehicles such as sea or air transport vehicles, planes, helicopters, submarines, boats, or drones, among other possibilities. The battery pack810can also be used as an energy storage system to power a building, such as a residential home or commercial building. Electric vehicles805can be fully electric or partially electric (e.g., plug-in hybrid) and further, electric vehicles805can be fully autonomous, partially autonomous, or unmanned. Electric vehicles805can also be human operated or non-autonomous. Electric vehicles805such as electric trucks or automobiles can include on-board battery packs810, batteries815or battery modules815, or battery cells820to power the electric vehicles805.

The electric vehicle805can include a chassis825(e.g., a frame, internal frame, or support structure). The chassis825can support various components of the electric vehicle805. The chassis825can span a front portion830(e.g., a hood or bonnet portion), a body portion835, and a rear portion830(e.g., a trunk, payload, or boot portion) of the electric vehicle805. The battery pack810can be installed or placed within the electric vehicle805. For example, the battery pack810can be installed on or within the chassis825of the electric vehicle805within one or more of the front portion830, the body portion835, or the rear portion840. The battery pack810can include or connect with at least one busbar, e.g., a current collector element. For example, the first busbar845and the second busbar850can include electrically conductive material to connect or otherwise electrically couple the battery815, the battery modules815, or the battery cells820with other electrical components of the electric vehicle805to provide electrical power to various systems or components of the electric vehicle805.

The vehicle805can include at least one motor100. For example, the vehicle805can include at least one motor100placed on, installed on, or coupled to the chassis825in the front portion830of the vehicle805. The vehicle805can include at least one motor100placed on, installed on, or coupled to the chassis825in the rear portion840of the vehicle805. For example, the vehicle805can be a dual motor vehicle805where a first motor100drives two front wheels855of the vehicle805and a second motor100drives two rear wheels855of the vehicle805. The vehicle805can be a quad motor vehicle805. The vehicle805can include a first motor100for driving a front driver side wheel855, a second motor100for driving a front passenger side wheel855, a third motor100for driving a rear driver side wheel855, and a fourth motor100for driving a rear passenger side wheel855.

The motors100can generate torque to cause the wheels855to spin, rotate, or transport the vehicle805. The motors100can cause the vehicle805to drive forward, drive in reverse, turn left, turn right, or brake. Because the motors100each can include a stator130that rotates within the motor100, each motor100can include the grounding ring115to ground the stator and prevent electric discharges that would otherwise result and degrade the performance of the motors100.

Referring toFIG.9, among others, a method900of grounding a rotor110of a motor100or providing an electrical path to ground with a ring115is shown. At least a portion of one ACT of the method900can be performed by a manufacturing or assembly apparatus. At least a portion of one ACT of the method900can be performed by an individual. At least a portion of one ACT of the method900can be performed by the motor100, the shaft105, the ring115. At least a portion of one ACT of the method900can be performed by a vehicle805. The method900can include an ACT905of providing a ring on a shaft. The method900can include an ACT910of coupling a rotor to the shaft. The method900can include an ACT915of providing an electrical path with the ring.

The method900can include an ACT905of providing the ring115on the shaft105. The ring115can be placed onto the shaft105at an end620. The ring115can be slid down the shaft105from the end620to a position at the end620of the shaft105. The ring115can be manufactured separately from the shaft105and assembled with the shaft105. The ring115can be manufactured on the shaft105. For example, the ring115can be cast or molded directly onto the shaft105. The ring115can be coupled, fixed, fixedly coupled, attached, or connected to the shaft105. The ring115can be fixed to the shaft105through a compressing or frictional force. For example, an inner diameter of the ring115may be slightly smaller than an outer diameter of the shaft105and therefore the ring115may apply a compressing force on the shaft105to fix the ring115to the shaft105. One or more nuts, washers, or bolts can fix the ring115to the shaft105. An adhesive or glue can fix the ring115to the shaft105. For example, an adhesive can be spread across at least a portion of the inner side150of the ring or on the outer surface145of the shaft105. The adhesive or glue can bond the ring115to the shaft105.

The method900can include an ACT910of coupling the rotor110to the shaft105. The shaft105and the ring115can be inserted into the rotor110. For example, the shaft105and the ring115can be inserted into the cavity135of the rotor110. For example, after the ring115is fixed to the shaft105, the shaft105including the ring115can be inserted into the cavity135. The end620of the shaft105can be inserted through an opening of the shaft105into the cavity135. The end620of the shaft105can be inserted through the cavity135to the end710.

The method900can include an ACT915of providing an electrical path with the ring115. Providing the electrical path can discharge rotor voltage from the rotor110with the ring115or ground the rotor110. Responsive to the ring115being inserted into the cavity135of the rotor110, the lips120can make contact with the inner surface140of the cavity135. The lips120can make an electrical contact with the inner surface140of the rotor110to electrically couple the ring115with the rotor110. The ring115can be electrically connected, electrically connected, electrically coupled, or in electrical contact with the shaft105. The shaft105can be in electrical contact or electrically coupled with the housing605of the motor100. The motor100can be fixed, coupled, or connected to the frame825of the vehicle805. The frame825can be a ground or electrically neutral component of the vehicle805. The ring115can ground the rotor110through the shaft105, the housing605, and the frame825. For example, the ring115can provide an electrical path from the rotor110to the frame825to ground the rotor110. Providing the electrical path can include connecting the shaft105to a ground via the ring115. Providing the electrical path via the ring115can include installing the motor100on a frame825of the vehicle805.

Referring toFIG.10, among others, a method1000of providing a motor100is shown. At least a portion of one ACT of the method1000can be performed by a manufacturing or assembly apparatus. At least a portion of one ACT of the method1000can be performed by a manufacturing or assembly individual. At least a portion of one ACT of the method1000can be performed by the motor100, the shaft105, or the ring115. The method1000can include an ACT1005of providing a motor. The method1000can include providing the motor100. The method1000can include providing the motor100including the ring115.

The ring115can be disposed on a shaft105. For example, the ring115can be disposed completely or partially on the shaft105. The ring115can be disposed on the shaft105in a position where the ring115is at least partially disposed within the cavity135of the rotor110. For example, the ring115can be disposed on a portion of the shaft105that is at least partially disposed within the cavity135. The ring115can include at least one lip120. The lips120can extend from a surface155of the ring115and contact an inner surface140of the cavity135. The lips120can extend fully or partially around an outer circumference205of the ring115. For example, each lip120can include a first side315and a second side320that extend from a surface155of the ring115. The first side315and the second side320can meet at an edge310. The edge310, the first side315, or the second side320of the lips120can contact, electrically contact, or electrically couple with the surface140of the cavity135. The edge310can contact the surface140around a rounded contour of the edge310.

The ring115can include multiple lips120. At least one lip120can create a seal between the lip120and the surface140of the cavity135to limit, prevent, or restrict the flow or movement of fluid within the cavity135. For example, two or more outer lips120can limit the amount of fluid that comes into contact with inner lips120. The inner lips120may remain free, or at least partially free, of the fluid and make an electrical contact with the inner surface140of the cavity135. The lips120can be angled. For example, the lips120can be angled towards the end165of the shaft105. The lips120can be angled away from the rotor110. The lips120can be angled away from the end620of the shaft105. The lips120can be angled away from a direction in which the ring115is inserted into the cavity135of the shaft105. For example, the ring115can be inserted in a direction from the end620towards the end165. The lips120can be angled away from a direction in which the shaft105is inserted into the cavity135. For example, the shaft105can be inserted into the cavity135in a direction from the opening705towards the end710.

In some examples, the ring including the lips can be used in any other type of liquid or oil cooled environment, not limited to motors. For example, in a driveline, a clutch, or any other apparatus with rotating components, a voltage may build up over time. The grounding ring described herein can ground the components, even if the components are liquid or oil cooled. Further relative parallel, perpendicular, vertical or other positioning or orientation descriptions include variations within +/−10% or +/−10 degrees of pure vertical, parallel or perpendicular positioning. References to “approximately,” “substantially” or other terms of degree include variations of +/−10% from the given measurement, unit, or range unless explicitly indicated otherwise. Coupled elements can be electrically, mechanically, or physically coupled with one another directly or with intervening elements. Scope of the systems and methods described herein is thus indicated by the appended claims, rather than the foregoing description, and changes that come within the meaning and range of equivalency of the claims are embraced therein.