Patent Description:
Compared with a conventional radial flux permanent magnet machine, an axial flux permanent magnet machine (axial flux permanent magnet machine, AFPMM) has obvious advantages of a more compact structure, a higher torque density, and high efficiency. In the conventional technology, in actual application, the axial flux permanent magnet machine does not rotate at a high speed, and has a structure that is mostly a surface-mounted structure. Therefore, for a structural strength of the axial flux permanent magnet machine, fixation of a magnetic steel and a rotor core with axial force is mainly considered. With miniaturization and an increasing rotation speed of a drive motor, a higher rotation speed of the axial flux permanent magnet machine poses a great challenge to a structural strength of a rotor, because there is large centrifugal force due to a large outer diameter of a rotor disk that moves at a high speed. In addition, with improvement of the rotor, a running frequency of the rotor also increases. As a result, there is obviously a greater eddy current loss of a conventional surface-mounted permanent magnet rotor structure, causing the rotor to heat up and have lower efficiency. Therefore, how to improve a structural strength of an axial flux motor and reduce a rotor loss to avoid some disadvantages of an existing surface-mounted axial flux permanent magnet machine currently becomes an urgent problem to be resolved for development of axial flux motor technologies and application thereof. <CIT> describes an axial air gap-type electric motor having a structure of permanent magnets and rotor cores.

The scope of the invention is set out in the appended claims. To resolve the foregoing problem, embodiments of this application provide a motor rotor, a drive motor, and an electric vehicle. Magnetic steels are reinforced in an axial direction and a radial direction, to improve reliability of the rotor running at a high rotation speed. A rotor yoke structure is improved to improve a magnetic circuit structure for a greater saliency ratio, and a greater electromagnetic reluctance torque, so that a torque density is further improved. SMC sheets are added, so that a loss of the magnetic steels is reduced, and efficiency is higher, thereby reduce heat of the rotor.

Therefore, the following technical solution is used in embodiments of this application:.

According to a first aspect, this application provides a motor rotor, including: one rotor core, where the rotor core includes one rotor yoke and at least two protruding components, and the at least two protruding components are disposed on a first surface of the rotor yoke; at least two grooves, where the groove is formed with two adjacent protruding components and the first surface of the rotor yoke; at least two magnetic steels that are separately disposed in the at least two grooves, where a quantity of the magnetic steels is the same as a quantity of the grooves; and one rotor pressing plate that is coupled to the at least two protruding components for fastening the at least two magnetic steels in the at least two grooves.

According to the invention, the rotor pressing plate is added to the protected motor rotor, and the rotor pressing plate is coupled to the rotor core to reinforce the magnetic steels in an axial direction, thereby improving reliability of the rotor in an axial direction. A structure of the rotor core is improved, and the plurality of protruding components are disposed on a surface of the rotor core. By improving a structure of the rotor yoke, a magnetic circuit structure is improved, so that a saliency ratio is increased, an electromagnetic reluctance torque is increased, and a torque density is increased.

In an implementation, the motor rotor further includes at least two sheets that are separately disposed in the at least two grooves, where one of the sheets is stacked on one of the magnetic steels, and a quantity of the sheets is the same as the quantity of the magnetic steels. The rotor pressing plate is further configured to fasten the at least two magnetic steels and the at least two sheets in the at least two grooves.

In this implementation, SMC sheets are added and attached to the magnetic steels, so that a loss of the magnetic steels is reduced, efficiency is improved, and heat of the rotor is reduced.

In an implementation, the at least two protruding components are disposed on the first surface of the rotor yoke at regular intervals along a circumferential direction.

According to the invention, the protruding components include a first component, a second component, and a third component, heights of the first component and the third component are the same, and heights of the first component and the second component are different, where the height is a length along a normal direction of the first surface of the rotor yoke, and the first component, the second component, and the third component are sequentially connected and disposed on the first surface of the rotor yoke.

In this implementation, the protruding components are designed into an inverted T-shaped structure. Shorter parts on two sides are for coupling to the rotor pressing plate, so that when the rotor core is coupled to the rotor pressing plate, a higher part in the middle of each of the protruding components, an upper surface of the rotor pressing plate, and an upper surface of the sheets are on a same horizontal plane, bringing a better whole look of the motor rotor.

In an implementation, a shape of the magnetic steel is the same as a shape of the groove.

In this implementation, the shape and a size of the magnetic steels generally need to match a groove between two protruding components on the first surface of the rotor yoke, to avoid an excessively large magnetic steel that cannot be disposed in the groove, or an excessively small magnetic steel that moves horizontally in the groove.

In an implementation, a shape of the sheet is the same as the shape of the groove.

In this implementation, the shape and a size of the sheets generally need to match a groove between two protruding components on the first surface of the rotor yoke, to avoid an excessively large sheet that cannot be disposed in the groove, or an excessively small sheet that moves horizontally in the groove.

In an implementation, the sheet is made of a soft magnetic composite material.

In this implementation, there is an effect that an eddy current loss of a motor can be reduced by taking advantage of features of the SMC such as magnetic conductivity and a low high-frequency loss.

In an implementation, the rotor pressing plate includes one pressing plate ring, at least two first radials, and at least two second radials, and a quantity of the first radials is the same as a quantity of the second radials, and is the same as a quantity of the protruding components; and the at least two first radials and the at least two second radials are disposed between each other, and one end of each of the at least two first radials and one end of each of the at least two second radials are fastened to the pressing plate ring, where a distance between a first radial and a second radial that are adjacent is equal to a distance between the first component and the third component.

In this implementation, the rotor pressing plate is designed into a gear structure, and each of the radials can be embedded into a lower part of each of the protruding components, so that the whole motor rotor is relatively not thick because the rotor pressing plate is not above a protruding part or on the upper surface of the sheets.

In an implementation, heights of the first radials and the second radials are the same as and equal to a difference between the heights of the first component and the second component.

In this implementation, a sum of a height of the radials and a height of the lower part on two sides of the protruding component is equal to a height of the higher part in the middle of the protruding component, so that when the rotor core is coupled to the rotor pressing plate, the higher part in the middle of each of the protruding components, the upper surface of the rotor pressing plate, and the upper surface of the sheets are on the same horizontal plane, bringing a better whole look of the motor rotor.

In an implementation, the first component and the third component each include at least one first fastening structure, and the first radial and the second radial each include at least one second fastening structure, where the at least two second fastening structures are coupled to the at least two first fastening structures in a one-to-one correspondence, to fasten the rotor pressing plate to the rotor core.

In this implementation, the plurality of fastening structures are disposed on the core yoke and the rotor pressing plate. The fastening structures on the core yoke are coupled to the fastening structures on the rotor pressing plate, so that the rotor pressing plate is fastened to the rotor core, thereby improving a structural strength of the motor rotor in the axial direction.

In an implementation, the motor rotor further includes a rotor support. The rotor support includes a support backing plate, a support outer ring, and a support inner ring, the support outer ring is disposed on an outer edge of the support backing plate, and the support inner ring is disposed at a central position of the support backing plate; and the rotor core is disposed in grooves between the support backing plate, the support outer ring, and the support inner ring.

In this implementation, by designing the rotor support into ring-shaped, disposing a support ring on an outer edge of the rotor support, and disposing another support ring at a central position of the rotor support, the rotor core is disposed on the rotor support, and the outer ring and the inner ring of the support are used as baffle plates, to prevent the magnetic steels and the sheets from falling off in a radial direction when the motor rotor rotates, thereby improving the structural strength of the motor rotor in the radial direction.

In an implementation, the support backing plate includes at least two third fastening structures. The at least two first fastening structures are coupled to the at least two third fastening structures in a one-to-one correspondence, to fasten the rotor core to the rotor support.

In this implementation, the plurality of fastening structures are disposed on the core yoke and the support backing plate. The fastening structures on the core yoke are coupled to the fastening structures on the support backing plate, so that the rotor core is fastened to the rotor support, thereby improving the structural strength of the motor rotor in the axial direction.

In an implementation, the pressing plate ring includes at least two fourth fastening structures, and the support inner ring includes at least two fifth fastening structures. The at least two fourth fastening structures are coupled to the at least two fifth fastening structures in a one-to-one correspondence, to fasten the rotor pressing plate to the rotor support.

In this implementation, the plurality of fastening structures are disposed on the pressing plate ring and the support inner ring. The fastening structures on the pressing plate ring are coupled to the fastening structures on the support inner ring, so that the rotor pressing plate is fastened to the rotor support, thereby improving the structural strength of the motor rotor in the axial direction.

In an implementation, the motor rotor further includes a core clamping ring that is disposed on an inner edge of a central through hole of the rotor yoke.

In this implementation, the core clamping ring is disposed between the support inner ring of the rotor support and the rotor core to ensure that there is no gap between the rotor support and the rotor core, so that a phenomenon that the rotor core shakes in the rotor support when the motor rotor rotates at a high speed is avoided.

In an implementation, the motor rotor further includes a sheath that is disposed on the outer edge of the rotor support.

In this implementation, the sheath is sleeved on an outer side of the rotor support to improve the strength of the motor rotor in the radial direction.

According to a second aspect, this application provides a drive motor, including at least one stator and a plurality of motor rotors according to the possible implementations of the first aspect, where every two of the motor rotors are disposed on two sides of one stator planar symmetrically.

According to a third aspect, this application provides an electric vehicle, including at least one drive motor according to the second aspect.

The accompanying drawings that need to be used for describing embodiments or the conventional technology are described briefly below.

Technical solution in embodiments of this application is described below with reference to the accompanying drawings in embodiments of this application.

In descriptions of this application, locations or location relationships indicated by terms "center", "up", "down", "front", "behind", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like are based on locations or location relationships shown in the accompanying drawings, and are merely intended for ease of describing this application and simplifying descriptions, instead of indicating or implying that a mentioned apparatus or element needs to be provided on a specific location or constructed and operated on a specific location, and therefore shall not be understood as limitations on this application.

In the descriptions of this application, it should be noted that, unless otherwise clearly specified and limited, terms "mount", "link", and "connect" should be understood in a broad sense, for example, may mean a fixed connection, may be a detachable connection, or may be a butt joint connection or an integrated connection. A person of ordinary skill in the art can understand specific meanings of the foregoing terms in this application based on specific cases.

In the descriptions of this specification, specific features, structures, materials, or characteristics may be combined in a proper manner in any one or more of embodiments or examples.

<FIG> is a schematic diagram of a structure of a drive motor according to an embodiment of this application. As shown in <FIG>, the drive motor includes a stator <NUM> and a rotor <NUM>, and the rotor <NUM> is disposed inside the stator.

In the drive motor, the stator <NUM> generally includes at least one stator punching and an armature winding, and the at least one stator punching is stacked to form a ring. A groove is provided on each stator punching, and a plurality of stator slots are formed on rings formed with a plurality of stacked stator punchings, and are used to nest the armature winding, so that when the armature winding is powered on, an alternating flux is generated inside the stator <NUM>.

The rotor <NUM> includes a rotating shaft <NUM> and two motor rotors (<NUM>-<NUM> and <NUM>-<NUM>). The motor rotor <NUM>-<NUM> and the motor rotor <NUM>-<NUM> are stacked planar symmetrically on two sides of the stator <NUM>, and are nested on the rotating shaft <NUM>. Magnetic steels are disposed inside the motor rotors <NUM>, so that a permanent magnet flux is generated on the whole rotor <NUM>. When an alternating current is input into the armature winding of the stator <NUM>, the generated alternating flux interacts with the permanent magnet flux generated on the rotor <NUM>, so that the rotor <NUM> rotates in the stator <NUM>.

In <FIG> of this application, only one stator <NUM> and the two motor rotors <NUM> are used as an example. This does not mean that the technical solution of this application is limited to the solution in <FIG>. For a person skilled in the art, quantities of stators <NUM> and motor rotors <NUM> of one drive motor are not limited to any specific quantity.

<FIG> are schematic diagrams of a structure of a motor rotor. As shown in the figures, the motor rotor <NUM> mainly includes a rotor core <NUM>, a plurality of magnetic steels <NUM>, a plurality of sheets <NUM>, a rotor pressing plate <NUM>, and a plurality of fastening components <NUM>. The plurality of magnetic steels <NUM> and the plurality of sheets <NUM> are fastened, by using the plurality of fastening components <NUM>, in grooves between the rotor core <NUM> and the rotor pressing plate <NUM>, to form the motor rotor <NUM>. Details are provided below.

As shown in <FIG> and <FIG>, the rotor core <NUM> includes a core yoke <NUM> and eight protruding components <NUM>. The core yoke <NUM> has a ring-shaped structure, and the eight protruding components <NUM> are disposed at regular intervals on a ring of the core yoke <NUM>, so that eight grooves <NUM> are formed on the ring of the core yoke <NUM>. In this application, the plurality of protruding components <NUM> are disposed on the rotor core <NUM>, so that when magnetic steels <NUM> are subsequently embedded into the grooves between the protruding components <NUM>, a saliency ratio is increased, a reluctance torque ratio is increased, and torque density is further increased. In addition, a quantity of magnetic steels for use is reduced.

In a sectional view shown in <FIG>, a shape of the protruding component <NUM> is an inverted T-shaped structure, and is a sector-shaped structure in a top view shown in <FIG>. For example, the protruding components <NUM> each include a first component <NUM>-<NUM>, a second component <NUM>-<NUM>, and a third component <NUM>-<NUM>, and the three components are connected and disposed on an upper surface of the core yoke <NUM> sequentially. The first component <NUM>-<NUM> and the third component <NUM>-<NUM> have different shapes, and heights of the first component <NUM>-<NUM> and the third component <NUM>-<NUM> are the same. A shape of the second component <NUM>-<NUM> is different from shapes of the first component <NUM>-<NUM> and the third component <NUM>-<NUM>, a height of the second component <NUM>-<NUM> is further different from the heights of the first component <NUM>-<NUM> and the third component <NUM>-<NUM>, and the height of the second component <NUM>-<NUM> is greater than the heights of the first component <NUM>-<NUM> and the third component <NUM>-<NUM>.

Each of the protruding components <NUM> designed in this application may have an irregular sector-shaped structure, to improve sinusoidal property of an air gap flux of the whole rotor <NUM>. For example, as shown in <FIG>, an intersection point P of extension lines on two sides of the protruding component <NUM> is not a circle center Q of the rotor core <NUM> , and an included angle between a side corresponding to an arc of an outer edge of the protruding component <NUM> and an extension line of a side of the protruding component <NUM> is θ, where θ is greater than or equal to <NUM>.

Optionally, an included angle between a side corresponding to an arc of an outer edge of each of the protruding components <NUM> and an extension line of a side of the protruding component <NUM> is θ, and the following formula is satisfied: <MAT> where
p is a quantity of magnetic poles of one motor rotor.

Further, with reference to <FIG> and <FIG>, a plurality of fastening structures are disposed on each of the protruding components <NUM>, so that the rotor pressing plate <NUM> is fastened to the rotor core <NUM> by using the fastening components <NUM> subsequently, to reinforce the rotor in an axial direction, thereby improving reliability of the rotor in the axial direction. Optionally, shapes of the fastening structures may be through holes, grooves, protrusions, or other shapes. In an example, a fastening structure <NUM> and a fastening structure <NUM> are disposed on the first component <NUM>-<NUM> and the third component <NUM>-<NUM> respectively, and shapes of the fastening structure <NUM> and the fastening structure <NUM> are circular through holes. The fastening components <NUM> may be members such as screws or snaps. This is not limited in this application.

In another example, a circular through hole fastening structure <NUM> and a circular through hole fastening structure <NUM> are disposed on the first component <NUM>-<NUM> and the third component <NUM>-<NUM> respectively, and a circular through hole fastening structure is further disposed at a position, on the core yoke <NUM>, corresponding to the fastening structure <NUM> and the fastening structure <NUM>, so that the rotor pressing plate <NUM> and the rotor core <NUM> are fastened to a core clamping ring <NUM> by using the fastening components <NUM> subsequently, to reinforce the rotor in the axial direction, thereby improving reliability of the rotor in the axial direction.

It should be noted that the rotor core <NUM> in this application is generally manufactured by sheet metal press forming. Therefore, the core yoke <NUM> and the eight protruding components <NUM> are an integrated structure. In the descriptions of the structure of the rotor core <NUM> in this application, words such as "connect" and "fasten" are used to facilitate description of a specific structure of the rotor core <NUM>. Clearly, the rotor core <NUM> may alternatively be formed by splicing one core yoke <NUM> and a plurality of protruding components <NUM>. This is not limited in this application.

In this embodiment of this application, eight protruding components <NUM> are shown in <FIG> and <FIG>, and a corresponding drive motor is an <NUM>-pole N-slot drive motor (N represents a quantity of stator slots of the stator <NUM>). Clearly, the drive motor used in the technical solution of this application is not limited to an <NUM>-pole N-slot drive motor, and may be a drive motor with any quantity of poles. Therefore, a quantity of the protruding components <NUM> is not limited in this application.

With reference to <FIG>, the motor rotor <NUM> includes eight magnetic steels <NUM>, and each of the magnetic steels <NUM> is embedded into a corresponding groove <NUM>. A shape of the magnetic steels <NUM> is a sector-shaped structure and matches a shape of the groove <NUM>. That is, the shape of the magnetic steels <NUM> is the same as a shape of the grooves formed with the first component <NUM>-<NUM> and the third component <NUM>-<NUM> of two adjacent protruding components <NUM> and the core yoke <NUM>, so that the magnetic steel <NUM> is disposed in the groove subsequently, and the magnetic steel <NUM> is pressed into the groove <NUM> by using the rotor pressing plate <NUM>, to prevent the magnetic steel <NUM> from shaking from side to side in the groove <NUM>. Optionally, a thickness of the magnetic steel <NUM> generally does not exceed the height of the second component <NUM>-<NUM>. Otherwise, the magnetic steel <NUM> cannot be fastened in the groove on the rotor core <NUM> by using the rotor pressing plate <NUM> subsequently.

A structure of the magnetic steel <NUM> may be an integrated structure, or may be a structure formed by splicing a plurality of sub-magnetic steels. For example, as shown in <FIG>, the magnetic steel <NUM> is formed by splicing five sub-magnetic steels, and a shape is still a sector-shaped structure. An included angle between a side corresponding to an arc of an outer edge of the sector-shaped structure and an extension line of a side of the sector-shaped structure is also θ. An inner circle radius of the sector is not less than an inner circle radius of the core yoke <NUM>, and an outer circle radius of the sector is not greater than an outer circle radius of the core yoke <NUM>.

A magnetizing direction of each of the magnetic steels <NUM> is axial magnetizing. That is, when the magnetic steels <NUM> are embedded into the grooves <NUM>, a direction of a magnetic field is parallel to a normal line of the upper surface of the core yoke <NUM>. Optionally, if the eight magnetic steels <NUM> are embedded into the corresponding grooves <NUM>, and directions of magnetic fields of adjacent magnetic steels <NUM> are opposite, that is, when an N pole of one of the magnetic steels <NUM> contacts a surface of the core yoke <NUM>, and an S pole faces upward, S poles of magnetic steels <NUM> on two sides of the magnetic steel <NUM> contact the surface of the core yoke <NUM>, and N poles face upward.

Further with reference to <FIG>, the motor rotor <NUM> includes eight sheets <NUM>, and each of the sheets <NUM> is embedded into a corresponding groove, and is stacked on each of the magnetic steels <NUM>. A shape of the sheets <NUM> is a sector-shaped structure and is similar to the shape of the magnetic steels <NUM>. That is, the shape of the sheets <NUM> is the same as the shape of the grooves formed with the first component <NUM>-<NUM> and the third component <NUM>-<NUM> of two adjacent protruding components <NUM> and the core yoke <NUM>, so that the sheet <NUM> is disposed in the groove subsequently, and the sheet <NUM> is pressed into the groove <NUM> by using the rotor pressing plate <NUM>, to prevent the sheet <NUM> from shaking from side to side in the groove <NUM>. Optionally, a sum of thicknesses of the magnetic steel <NUM> and the sheet <NUM> is equal to the height of the second component <NUM>-<NUM>, so that when the rotor pressing plate <NUM> is coupled to the rotor core <NUM> subsequently, the magnetic steel <NUM> and the sheet <NUM> are fastened to the rotor core <NUM>, and an upper surface of the second component <NUM>-<NUM>, an upper surface of the rotor pressing plate <NUM>, and an upper surface of the sheet <NUM> are on a same horizontal plane after fastening, bringing a better look of an overall structure.

Optionally, for the sheet <NUM> shown in <FIG>, groove structures <NUM> are provided on two sides of the sector along an axial direction. A shape of the groove structures <NUM> is a stepped shape. That is, a rectangular structure is removed from the two sides of the sector of the sheet <NUM> along the axial direction, so that there is a stepped surface on each of the two sides of the sheet <NUM>, and the stepped surface is parallel to an upper surface of the sheet <NUM>. The groove structures <NUM> are provided on the two sides of the sector of the sheet <NUM>, so that when the magnetic steels <NUM> and the sheets <NUM> are disposed in the grooves <NUM>, the rotor pressing plate <NUM> applies a downward force perpendicular to the upper surface of the core yoke <NUM> on the stepped surfaces on the two sides of the sheet <NUM>. In this way, the magnetic steels <NUM> and the sheets <NUM> are fastened in a direction perpendicular to the upper surface of the core yoke <NUM>.

In this embodiment of this application, the sheets <NUM> may be soft magnetic composite (soft magnetic composite, SMC) sheets, and are generally die-casted by using a high permeability powder. In this application, the sheets <NUM> are added, so that a Q-axis inductance can be increased to some degree, thereby increasing an effect of a reluctance torque. In addition, there is an effect that an eddy current loss of a motor can be reduced by taking advantage of features of the SMC such as magnetic conductivity and a low high-frequency loss.

As shown in <FIG>, the rotor pressing plate <NUM> includes one pressing plate ring <NUM>, eight first radials <NUM>, and eight second radials <NUM>. A shape of the pressing plate ring <NUM> is ring-shaped, and an outer circle radius of the ring is less than or equal to the inner circle radius of the core yoke <NUM>.

Both the first radials <NUM> and the second radials <NUM> have a sector-shaped structure. One of the first radials and one of the second radials form a group, and are disposed on an outer edge of the pressing plate ring <NUM>. A distance between each of the first radials <NUM> and each of the second radials <NUM> is related to the protruding components <NUM>, and a distance between a group of radials and another group of radials is related to a distance between each of the protruding components on the rotor core <NUM>. To be specific, when the rotor pressing plate <NUM> is embedded into the rotor core <NUM>, the first radial <NUM> and the second radial <NUM> in each group are coupled to the first component <NUM>-<NUM> and the third component <NUM>-<NUM> on each of the protruding component <NUM> respectively.

Optionally, heights of the first radials <NUM> and the second radials <NUM> are a difference between heights of the first component <NUM>-<NUM> (and the third component <NUM>-<NUM>) and the second component <NUM>-<NUM> that are of the protruding component <NUM>. When the rotor pressing plate <NUM> is embedded into the rotor core <NUM>, the first radial <NUM> is on an upper surface of the first component <NUM>-<NUM> (or the third component <NUM>-<NUM>), and the second radial <NUM> is on an upper surface of the third component <NUM>-<NUM> (or the first component <NUM>-<NUM>), so that the upper surface of the second component <NUM>-<NUM>, the upper surface of the rotor pressing plate <NUM>, and the upper surface of the sheet <NUM> are on the same horizontal plane after fastening, bringing a better look of an overall structure.

As shown in <FIG>, one fastening structure <NUM>-<NUM> and one fastening structure <NUM>-<NUM> are disposed on each of the first radials <NUM> and each of the second radials <NUM> respectively. When the rotor pressing plate <NUM> is coupled to the rotor core <NUM>, the fastening structure <NUM>-<NUM> is aligned with the fastening structure <NUM> on the first component <NUM>-<NUM> (or aligned with the fastening structure <NUM> on the third component <NUM>-<NUM>). The fastening structure <NUM>-<NUM> is aligned with the fastening structure <NUM> on the third component <NUM>-<NUM> (or aligned with the fastening structure <NUM> on the first component <NUM>-<NUM>). Then, the rotor pressing plate <NUM> is fastened to the rotor core <NUM> by using the fastening components <NUM>, to reinforce the rotor in the axial direction, thereby improving reliability of the rotor in the axial direction. Preferably, shapes of the fastening structure <NUM>-<NUM> and the fastening structure <NUM>-<NUM> may be through holes, grooves, protrusions, or other shapes.

Optionally, as shown in <FIG>, for one group including the first radial <NUM> and the second radial <NUM>, a protruding structure <NUM>-<NUM> is disposed along an axial direction on a side that is of the first radial <NUM> and that faces away from the second radial <NUM>, and a protruding structure <NUM>-<NUM> is disposed along the axial direction on a side that is of the second radial <NUM> and that faces away from the first radial <NUM>. The protruding structure <NUM>-<NUM> and the protruding structure <NUM>-<NUM> have an inverted stepped shape. That is, rectangular structures are removed along the axial direction from sides that are of the first radial <NUM> and the second radial <NUM> and that face away from each other, so that there is a downward stepped surface on each of the sides that are of the first radial <NUM> and the second radial <NUM> and that face away from each other. The stepped surfaces are parallel to upper surfaces of the first radial <NUM> and the second radial <NUM> respectively. When the rotor pressing plate <NUM> is coupled to the rotor core <NUM>, the protruding structure <NUM>-<NUM> and the protruding structure <NUM>-<NUM> are coupled to the groove structures <NUM> on the two sides of the sheet <NUM> respectively, so that the rotor pressing plate <NUM> applies, with the protruding structure <NUM>-<NUM> and the protruding structure <NUM>-<NUM>, a force to the groove structures <NUM> on the two sides of the sheet <NUM>, and the magnetic steels <NUM> and the sheets <NUM> are fastened between the rotor core <NUM> and the rotor pressing plate <NUM>.

Further, optionally, as shown in <FIG>, a plurality of fastening structures <NUM>-<NUM> are disposed on the pressing plate ring <NUM>, and the plurality of fastening structures <NUM>-<NUM> are evenly distributed on the pressing plate ring <NUM>. In this application, the plurality of fastening structures <NUM>-<NUM> are disposed on the pressing plate ring <NUM> to use the plurality of fastening components <NUM> subsequently for being coupled to fastening structures on a rotor support <NUM>, to fasten the rotor pressing plate <NUM> to the rotor support <NUM> and reinforce the rotor in the axial direction, thereby improving reliability of the rotor in the axial direction.

In this embodiment of this application, the eight magnetic steels <NUM> and the eight sheets <NUM> are disposed in the eight grooves <NUM> on the rotor core <NUM> respectively, and then the rotor pressing plate <NUM> is disposed on the rotor core <NUM>, so that the first radials <NUM> and the second radials <NUM> of the rotor pressing plate <NUM> are on the first component <NUM>-<NUM> and the third component <NUM>-<NUM> respectively. Then, the plurality of fastening components <NUM> are embedded into the fastening structures on the rotor pressing plate <NUM> and the rotor core <NUM>, so that the rotor pressing plate <NUM> is fastened to the rotor core <NUM>, and the magnetic steels <NUM> and the sheets <NUM> are fastened to the grooves on the rotor core <NUM>. A structural effect after fastening is shown in <FIG>.

In this embodiment of this application, the rotor pressing plate <NUM> is added, and the fastening structures are disposed on the rotor core <NUM> and the rotor pressing plate <NUM>, to reinforce the magnetic steels <NUM> in the axial direction, thereby improving reliability of the rotor in the radial direction. A structure of the rotor core is improved, and the plurality of protruding components are disposed on a surface of the rotor core. By improving a structure of the rotor yoke, a magnetic circuit structure is improved, so that a saliency ratio is increased, an electromagnetic reluctance torque is increased, and a torque density is increased. The SMC sheets are added and attached to the magnetic steels, so that a loss of the magnetic steels is reduced, efficiency is improved, and heat of the rotor is reduced.

Further with reference to <FIG>, in this structure, the magnetic steels <NUM> and the sheets <NUM> that are fastened to the rotor pressing plate <NUM> and the rotor core <NUM> are not fastened on inner sides and outer sides of the magnetic steels <NUM> and the sheets <NUM>. When the structure is nested on the rotating shaft <NUM> and rotates with the rotating shaft <NUM>, a centripetal force and a centrifugal force are generated. The magnetic steels <NUM> and the sheets <NUM> move, easily along the axial direction, towards a circle center of the rotor core <NUM> or away from the circle center of the rotor core <NUM>.

Therefore, in this application, the motor rotor <NUM> further includes the rotor support <NUM>. The rotor support <NUM> is fastened to the rotor core <NUM>, and forms eight enclosed cavities with the rotor core <NUM> and the rotor pressing plate <NUM>, so that the magnetic steels <NUM> and the sheets <NUM> are in the enclosed cavities, and it is ensured that the magnetic steels <NUM> and the sheets <NUM> do not rotate with the rotor <NUM> along the axial direction and move towards the circle center of the rotor core <NUM> or away from the circle center of the rotor core <NUM>.

For example, as shown in <FIG>, the rotor support <NUM> includes a support backing plate <NUM>, a support outer ring <NUM>, and a support inner ring <NUM>. The support backing plate <NUM> has a disk-shaped structure, and there is one through hole in the middle of the disk-shaped structure. A radius of the through hole is equal to a radius of the rotating shaft <NUM>, so that the rotor support <NUM> can be nested on the rotating shaft <NUM>.

A plurality of fastening structures <NUM>-<NUM> are disposed on the support backing plate <NUM>, and a position of each of the fastening structures <NUM>-<NUM> on the support backing plate <NUM> matches a position of each of the fastening structures on the rotor core <NUM>. The structure shown in <FIG> is disposed on the support backing plate <NUM>, and each of the fastening structures on the rotor core <NUM> is aligned with each of the fastening structures <NUM>-<NUM> on the support backing plate <NUM>, to fasten the rotor core <NUM> and the rotor pressing plate <NUM> to the support backing plate <NUM> by using the fastening components <NUM> and reinforce the rotor in the axial direction, thereby improving reliability of the rotor in the axial direction.

The support outer ring <NUM> is disposed on an outer edge of the support backing plate <NUM>, and an inner circle radius of the support outer ring is equal to the outer circle radius of the core yoke <NUM> of the rotor core <NUM>, so that the structure shown in <FIG> can be embedded into the rotor support <NUM> to provide a function of a baffle plate for outer sides of the magnetic steels <NUM> and the sheets <NUM>, to prevent the magnetic steels <NUM> and the sheets <NUM> from rotating with the rotor <NUM> and moving, in the axial direction, away from the circle center of the rotor core <NUM> with a centrifugal force, thereby reinforcing the rotor in a radial direction and improving reliability of the rotor in the radial direction.

A first rib <NUM>-<NUM> and a second rib <NUM>-<NUM> are provided on an upper end and a lower end of the support outer ring <NUM> respectively, where an extension direction of the two ribs is away from a circle center of the support outer ring <NUM>; and are configured to be coupled to a sheath <NUM> sleeved on the support outer ring <NUM> subsequently to provide upper and lower baffle plates for the sheath, to prevent the sheath <NUM> from falling off from the support outer ring <NUM>.

The support inner ring <NUM> is disposed at the center of the support backing plate <NUM>, and an outer circle radius of the support inner ring is equal to the inner circle radius of the core yoke <NUM> of the rotor core <NUM>, so that the structure shown in <FIG> can be embedded into the rotor support <NUM> to provide a function of a baffle plate for the outer sides of the magnetic steels <NUM> and the sheets <NUM>, to prevent the magnetic steels <NUM> and the sheets <NUM> from rotating with the rotor <NUM> and moving, in the axial direction, towards the circle center of the rotor core <NUM> with a centripetal force, thereby reinforcing the rotor in the radial direction and improving reliability of the rotor in the radial direction.

A plurality of fastening structures <NUM>-<NUM> are disposed on an upper surface of the support inner ring <NUM>, and a position of each of the fastening structures <NUM>-<NUM> on the support inner ring <NUM> matches a position of each of the fastening structures <NUM>-<NUM> on the pressing plate ring <NUM> of the rotor pressing plate <NUM>. The structure shown in <FIG> is disposed on the support backing plate <NUM>, and each of the fastening structures <NUM>-<NUM> and fastening structures <NUM>-<NUM> on the pressing plate ring <NUM> of the rotor pressing plate <NUM> is aligned with each of the fastening structures <NUM>-<NUM> on the support inner ring <NUM>, to fasten the rotor pressing plate <NUM> to the support backing plate <NUM> by using the fastening components <NUM>.

A fastening ring <NUM>-<NUM> is disposed on the upper surface of the support inner ring <NUM>. An outer circle radius of the fastening ring <NUM>-<NUM> is equal to an inner circle radius of the pressing plate ring <NUM> of the rotor pressing plate <NUM>, and heights of the support inner ring <NUM> and the fastening ring <NUM>-<NUM> (lengths in a normal direction of the upper surface of the support backing plate <NUM>) are the same as a height of the rotor core <NUM>. When the structure shown in <FIG> is disposed on the support backing plate <NUM>, the fastening ring <NUM>-<NUM> is coupled to the pressing plate ring <NUM> of the rotor pressing plate <NUM>, to prevent the pressing plate ring <NUM> from collapsing towards the support backing plate <NUM>.

In this application, the motor rotor <NUM> further includes a core clamping ring <NUM>. The core clamping ring <NUM> is generally a ring-shaped structure made of a high-strength light metal. An inner circle radius of the core clamping ring <NUM> is equal to an outer circle radius of the support inner ring <NUM> of the rotor support <NUM>, and an outer circle radius of the core clamping ring <NUM> is equal to an inner circle radius of the rotor core <NUM>. When the structure shown in <FIG> is embedded into the rotor support <NUM>, the core clamping ring <NUM> may be embedded into a gap between the structure shown in <FIG> and the rotor support <NUM>, so that the two are coupled with no gap.

Optionally, as shown in <FIG>, a chamfer <NUM>-<NUM> is provided at one end of the core clamping ring <NUM>, and an extension direction of the chamfer <NUM>-<NUM> is towards a circle center of the core clamping ring <NUM>. After the core clamping ring <NUM> is embedded into the gap between the structure shown in <FIG> and the rotor support <NUM>, the core clamping ring <NUM> may be removed from the gap through the chamfer <NUM>-<NUM>.

In this application, the motor rotor <NUM> further includes the sheath <NUM>. As shown in <FIG>, the sheath <NUM> is generally a ring-shaped structure made of a carbon fiber, and is sleeved on an outer side of the support outer ring <NUM>, to improve a strength of the rotor <NUM> in the radial direction with a high-speed centrifugal force and further reinforce the rotor in the radial direction, thereby improving reliability of the rotor in the radial direction.

In embodiments of this application, in the protected motor rotor, the plurality of fastening structures are disposed on the components such as the rotor core, the rotor pressing plate, and the rotor support, and then the components are fastened to each other by using fastening components such as screws and snaps, to improve reliability of the rotor in the axial direction. Both inner and outer sides of the rotor core are fastened by adding the support inner ring and the support outer ring of the rotor support. In addition, the fiber sheath is added for reinforcement, to ensure reliability of the rotor in the radial direction at a high rotation speed. A structure of the rotor yoke is improved, and the plurality of fastening components are disposed on a surface of the rotor yoke, to improve a magnetic circuit structure, so that a saliency ratio is increased, an electromagnetic reluctance torque is increased, and a torque density is increased. The SMC sheets are added and attached to the magnetic steels, so that a loss of the magnetic steels is reduced, efficiency is improved, and heat of the rotor is reduced.

In the technical solution of this application described above, an <NUM>-pole N-slot axial flux permanent magnet machine is used as an example. Clearly, the solution under protection in this application is not limited to the <NUM>-pole N-slot axial flux permanent magnet machine, and may be a drive motor with any quantity of poles. This is not limited in this application.

An embodiment of this application further provides an electric vehicle, including at least one drive motor. The drive motor may be the drive motor described in <FIG> and corresponding content. Because the electric vehicle includes the drive motor, the electric vehicle has all or at least some of advantages of the drive motor.

Claim 1:
A motor rotor, comprising:
one rotor core (<NUM>), wherein the rotor core comprises one rotor yoke (<NUM>) and at least two protruding components (<NUM>), and the at least two protruding components are disposed on a first radial surface of the rotor yoke, the radial surface being perpendicular to the axial direction of the rotor, wherein each of the protruding components comprise a first component (<NUM>-<NUM>), a second component (<NUM>-<NUM>), and a third component (<NUM>-<NUM>), heights of the first component and the third component are the same, and height of the second component is greater than the heights of the first and third components, wherein the height is a length along a normal direction of the first surface of the rotor yoke, and
the first component, the second component, and the third component are sequentially connected in that order and disposed on the first radial surface of the rotor yoke;
at least two grooves (<NUM>), wherein the groove is formed with two adjacent protruding components and the first radial surface of the rotor yoke;
at least two permanent magnets (<NUM>) comprising magnetic steel that are separately disposed in the at least two grooves, wherein a quantity of the permanent magnets is the same as a quantity of the grooves; and
one rotor pressing plate (<NUM>) that is coupled to the at least two protruding components for fastening the at least two permanent magnets in the at least two grooves,
wherein the one rotor pressing plate comprises one pressing plate ring (<NUM>) and at least two groups of radials, the radials being protrusions extending outwards from the pressing plate ring in radial direction,
where a quantity of the groups of radials is the same as a quantity of the protruding components, where each group of radials comprises a first radial (<NUM>) and a second radial (<NUM>), wherein the first radial and the second radial in each group are coupled to the first component and the third component on each protruding component respectively.