Motor rotor with enveloping body

Abstract

A motor rotor with an enveloping body comprises a rotor main body, the rotor main body is provided with a dovetail groove formed by fixing ribs, and a magnetic shoe is fixed in the dovetail groove; the upper surface of the fixing rib is lower than the upper cambered surface of the magnetic tile; the magnetic shoes are embedded in the dovetail grooves, and enveloping bodies are arranged on the peripheries of the magnetic shoes to seal and fix the magnetic shoes and the fixing ribs. The magnetic shoes and the fixing ribs are sealed and fixed through the enveloping bodies, so that the binding force of the magnetic shoes and the rotor main body is increased, gaps are not easy to generate at the joints of the magnetic shoes and the dovetail grooves, and the problems that vibration is easy to generate under the condition of high rotating speed, air gaps are enlarged, the magnetic shoes are thrown away and separated, or the fixing ribs are broken are solved.

Description

Technical Field

[0001] The invention relates to the technical field of motors, and in particular to a motor rotor with an envelope. Background Art

[0002] Existing inner rotor brushless motors are divided into two types of structures: embedded magnets and surface mounted magnets. The analysis of these two types of structures is as follows: The magnets in the embedded magnet structure are installed inside the rotor laminations. They have high stability and can be used in high speed (10000-40000RPM) environments. However, part of the magnetic field is shielded by the iron core, and the actual electrical air gap is relatively large, resulting in low air gap magnetic density and low power density.

[0003] The existing surface mount magnet rotor installation structure is mainly to glue the magnet directly to the rotor laminations with glue, and then add a magnetic ring on the outside. The magnetic ring can ensure the stability of the magnetic tile and rotor structure, protect the magnetic tile, and prevent the magnetic tile from detaching at high speed. However, due to the addition of the magnetic ring, the actual electrical air gap is relatively large, resulting in low air gap magnetic density, low power density, and cannot have a very high speed limit.

[0004] In addition to the above structure, the existing surface mount magnet installation structure can also glue the magnet directly to the rotor lamination with glue, and then there is no magnetic ring outside. This structure has no gap in the magnetic ring and has better magnetic performance, but it can only be used in low speed (below 6000RPM) environment. In a high speed environment, it is difficult to fix the magnetic tile only by the adhesive force of glue, and the problem of magnetic tile flying off is easy to occur, causing damage to the motor.

[0005] The invention patent with the prior art publication number CN104135098A proposes a medium-to-high speed permanent magnet brushless motor rotor, including permanent magnets, silicon steel sheets and motor shafts. The cross section of the motor shaft inside the rotor is square, and each corner of the square cross-section shaft corresponds to the center point of the magnetic steel surface. The present invention breaks away from the constraints of the conventional design ideas of the traditional motor rotor magnetic circuit and the motor extension shaft, and changes the internal shaft structure of the motor. When a round shaft with a small diameter produces a large shear stress in an overload state, it may cause a displacement relative to the main magnetic pole, causing damage to the motor. When the use of an internal square shaft or polygonal shaft form is prone to uneven distribution of local magnetic lines of force and the contradiction that the local magnetic flux is easy to reach saturation, the layout structure of the internal square shaft is adjusted in the direction, thereby optimizing the motor rotor magnetic circuit structure, solving the problem of easy saturation of local magnetic flux in the previous design structure, improving the utilization rate of permanent magnets, reducing iron loss, and effectively improving the motor operation efficiency. Summary of the invention

[0006] In order to make the motor reach a higher speed, a surface-mount magnet structure with a smaller air gap is required. However, under high speed conditions, it is difficult to fix the magnetic tiles by the adhesive force of glue alone, and the magnetic tiles are prone to flying off, causing damage to the motor.

[0007] To solve the above problems, the technical solution provided by the present invention is: a motor rotor with an envelope, including a rotor body, a dovetail groove formed by fixing ribs is provided on the rotor body, and a magnetic tile is fixed in the dovetail groove; the upper surface height of the fixing ribs is lower than the upper arc surface of the magnetic tile; the magnetic tile is embedded in the dovetail groove, and an envelope is provided around the magnetic tile to seal and fix the magnetic tile and the fixing ribs. The envelope is formed by injection molding in the gap around the magnetic tile, and the injection molding process can be filled with injection molding materials or single-component or multi-component liquid-solid glue.

[0008] Sealing and fixing the magnetic tiles and fixing ribs through the envelope not only increases the bonding force between the magnetic tiles and the rotor body, but also makes it less likely for gaps to form at the junction of the magnetic tiles and the dovetail grooves. It is also less likely for vibrations to occur under high speed conditions, leading to larger air gaps, the magnetic tiles flying off, or the fixing ribs breaking.

[0009] Specifically, the rotor body is cylindrical as a whole, and a plurality of fixing ribs are arranged on the cylindrical side of the rotor body, and the upper surface height of the fixing ribs is lower than the upper arc surface of the magnetic tile.

[0010] Specifically, the envelope body forms an envelope ring on the cylindrical end face of the rotor body, and the envelope ring engages the step groove to fix the magnetic tile; the envelope body covers the low-lying oblique angle area of ​​the fixed rib and the magnetic tile to form an envelope strip, and the surface of the envelope strip and the arc surface on the magnetic tile together form the arc surface of the motor rotor.

[0011] Specifically, an enveloping fixing wire is provided where the enveloping strip covers the fixing rib, the enveloping fixing wire is embedded in the injection molding groove on the upper surface of the fixing rib, and the enveloping fixing wire is clamped and fixed by the injection molding groove with a wider bottom and a narrower notch.

[0012] Specifically, the side of the fixing rib close to the surface of the rotor body is a thin end, the side of the fixing rib away from the rotor body is a thick end, the adjacent fixing ribs serve as two sides of the dovetail groove, and the dovetail groove is formed between the adjacent fixing ribs.

[0013] Specifically, a plurality of injection molding grooves are arranged on the surface of the fixed rib away from the rotor body. The cross section of the injection molding groove is a trapezoid that is small at the top and large at the bottom, and the groove opening is narrower than the bottom.

[0014] Specifically, step grooves are provided at both ends of the magnetic shoe near the cylindrical end surface of the rotor body, low-lying beveled areas are provided on both sides of the upper arc surface of the magnetic shoe near the fixed rib, and the edge of the upper arc surface sinks smoothly in the low-lying beveled area.

[0015] Specifically, the surface of the magnetic tile is exposed as a whole, and the envelope only seals and wraps the step grooves at both ends of the magnetic tile and the connection part between the magnetic tile and the fixing rib.

[0016] Specifically, a plurality of rubber storage grooves are provided on the surface of the rotor body and at the joint portion with the bottom of the magnetic tile.

[0017] Specifically, the arc length angle of the side edges of the covering surface of the envelope on the fixed rib and the low-lying oblique angle area of ​​the magnetic tile is between 25 degrees and 45 degrees, and the thickness of the envelope is less than 4 mm.

[0018] Specifically, the chamfer angle of the side of the dovetail groove is between 40° and 50°.

[0019] The beneficial effects of the present invention are as follows: a magnetic tile with a step groove and a rotor body with a dovetail groove structure and an injection-molded integrated envelope are designed. The dovetail groove of the rotor body clamps the magnetic tile, and cooperates with the step groove structure at both ends of the magnet to fix the injection-molded envelope structure at both ends of the rotor body. At the same time, in order to prevent the plastic from falling off during high-speed operation after the plastic is coated, an injection groove is added on the fixed rib to increase the bonding force between the lamination and the plastic coating, thereby ensuring the stability of the product's high-speed operation. Combining these structures, the problem of high-speed brushless motors increasing the stator-rotor magnetic gap due to the increase in the magnetic protection ring, resulting in low magnetic density, low motor efficiency and other performance degradation, and the problem of uneven glue addition causing the magnet to fall off, the new structure is simple in process, stable and reliable, and can be applied to operating environments with higher speeds. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a side sectional view of the entire motor rotor of the present invention.

[0021] Figure 2 It is an exploded view of the overall structure of the motor rotor of the present invention.

[0022] Figure 3 It is a partial cross-sectional view of the second embodiment of the present invention.

[0023] Figure 4 It is a partial cross-sectional view of the third embodiment of the present invention.

[0024] Figure 5 It is a partial cross-sectional view of the fourth embodiment of the present invention.

[0025] Figure 6 It is a structural diagram of the magnetic tile in the present invention.

[0026] In the figure, 1 is the rotor body, 2 is the magnetic tile, 2-1 is the step groove, 2-2 is the low-lying beveled area, 3 is the envelope body, 3-1 is the envelope strip, 3-2 is the envelope ring, 4 is the fixing rib, 5 is the injection molding groove, 6 is the glue storage groove, 7 is the injection molding gap, 8 is the injection molding chamfer, and 9 is the injection molding fillet. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0028] Embodiment 1: A motor rotor with an envelope 3, such as Figure 1 and Figure 2 As shown, the rotor body 1 includes a dovetail groove, and a magnetic tile 2 is fixed in the dovetail groove; after the magnetic tile 2 is embedded in the dovetail groove, an envelope 3 is formed around the magnetic tile 2 by injection molding to fix the magnetic tile 2 on the rotor body 1. The injection molding process can use injection molding materials or single-component or multi-component liquid-solid glue filling.

[0029] The rotor body 1 is cylindrical as a whole, and 4 fixing ribs 4 arranged along the axial direction are provided on the side of the cylinder. The side of the fixing rib 4 is approximately an inverted trapezoid with a large top and a small bottom. The end away from the surface of the rotor body 1 is a wide end, and the junction with the rotor body 1 is a small end. The side of the inverted trapezoid of the fixing rib 4 serves as the side of the dovetail groove. Two adjacent fixing ribs 4 are combined into a dovetail groove, and the side of the dovetail groove is provided with a circular chamfer. The magnetic tile 2 is inserted into the dovetail groove to complete the initial fixation. The angle of the chamfer of the side of the dovetail groove, that is, the angle between the side of the fixing rib 4 and the tangent of the surface of the rotor body 1 is between 40° and 50°. If the chamfer is too large, it is not easy to initially fix the magnetic tile 2. If the chamfer is too large at high speed, the fixing rib 4 will exert less pressure on the magnetic tile 2, and the magnetic tile 2 will easily fly away; if the chamfer is small at high speed, the fixing rib 4 itself cannot withstand excessive pressure and is prone to breakage, causing motor failure. At the same time, the surface arc length of the wide end of the fixing rib 4 should not be too long, and the number of ribs should not be too many, otherwise the exposed area of ​​the magnetic tile 2 on the motor rotor will be small, affecting the magnetic efficiency of the motor rotor surface.

[0030] like Figure 6 As shown, the two ends of the magnetic tile 2 close to the cylindrical end surface of the rotor body 1 are provided with step grooves 2-1. After the magnetic tile 2 is initially fixed in the dovetail groove, the magnetic tile 2 and the rotor body 1 are put into the injection mold for injection molding, and an envelope 3 is formed around the cylindrical end surface of the rotor body 1 and the surface of the fixing rib 4, that is, around the magnetic tile 2. The injection molding process can use injection molding materials or single-component or multi-component liquid-solid glue filling. The envelope 3 wraps a circle of magnetic tiles 2 on the cylindrical end face of the rotor body 1 and engages with the step groove 2-1 for reinforcement; at the same time, a plurality of injection molding grooves 5 are provided on the surface of the side of the fixing rib 4 away from the rotor body 1. The cross-section of the injection molding groove 5 is a trapezoidal shape with a small top and a large bottom, and the groove opening is narrower than the bottom. During injection molding, the envelope 3 covers the fixing rib 4 and the low-lying beveled area 2-2 of the magnetic tiles 2. The structure of the injection molding groove 5 with a small top and a large bottom can engage with the main envelope 3, and can hold the envelope 3 under high speed conditions. The envelope 3 reinforces the magnetic tiles 2 by engaging the step groove 2-1 at the end face, ensuring that the magnetic tiles 2 will not be thrown off under high speed conditions.

[0031] In order to ensure the magnetic density and magnetic efficiency on the surface of the rotor body 1, it is necessary to ensure the coverage rate of the magnetic tile 2 on the surface of the rotor body 1, so the side arc length angle of the covering surface of the envelope 3 at the contact between the fixed rib 4 and the magnetic tile 2 is 25° to 35°. Too little coverage will affect the reinforcement strength of the envelope 3, and too much coverage will affect the effective magnetic density of the magnetic tile 2.

[0032] The surface of the rotor body 1 is provided with a plurality of glue grooves 6 at the bottom joint part of the magnetic tile 2. When the magnetic tile 2 is inserted into the dovetail groove for preliminary fixation, glue can be injected through the glue groove 6 for preliminary fixation to further increase the structural strength.

[0033] Embodiment 2: A motor rotor with an envelope 3 comprises a rotor body 1, a dovetail groove is provided on the rotor body 1, and a magnetic tile 2 is fixed in the dovetail groove; after the magnetic tile 2 is embedded in the dovetail groove, an envelope 3 is formed around the magnetic tile 2 by injection molding to fix the magnetic tile 2 on the rotor body 1.

[0034] The rotor body 1 is cylindrical as a whole, and 4 fixing ribs 4 arranged along the axial direction are provided on the side of the cylinder. The side of the fixing rib 4 is approximately an inverted trapezoid with a large top and a small bottom. The end away from the surface of the rotor body 1 is a wide end, and the junction with the rotor body 1 is a small end. The side of the inverted trapezoid of the fixing rib 4 serves as the side of the dovetail groove. Two adjacent fixing ribs 4 are combined into a dovetail groove, and the side of the dovetail groove is provided with a circular chamfer. The magnetic tile 2 is inserted into the dovetail groove to complete the initial fixation. The angle of the chamfer of the side of the dovetail groove, that is, the angle between the side of the fixing rib 4 and the tangent of the surface of the rotor body 1 is between 40° and 50°. If the chamfer is too large, it is not easy to initially fix the magnetic tile 2. If the chamfer is too large at high speed, the fixing rib 4 will exert less pressure on the magnetic tile 2, and the magnetic tile 2 will easily fly away; if the chamfer is small at high speed, the fixing rib 4 itself cannot withstand excessive pressure and is prone to breakage, causing motor failure. At the same time, the surface arc length of the wide end of the fixing rib 4 should not be too long, and the number of ribs should not be too many, otherwise the exposed area of ​​the magnetic tile 2 on the motor rotor will be small, affecting the magnetic efficiency of the motor rotor surface.

[0035] The two ends of the magnetic tile 2 close to the cylindrical end surface of the rotor body 1 are provided with step grooves 2-1. After the magnetic tile 2 is initially fixed in the dovetail groove, the magnetic tile 2 and the rotor body 1 are put into the injection mold for injection molding, and an envelope 3 is formed on the cylindrical end surface of the rotor body 1 and the surface of the fixed rib 4, that is, around the magnetic tile 2. The envelope 3 wraps a circle of magnetic tile 2 on the cylindrical end surface of the rotor body 1, engages with the step groove 2-1, and is reinforced; at the same time, a plurality of injection grooves 5 are provided on the surface of the fixed rib 4 away from the rotor body 1. The cross section of the injection groove 5 is a trapezoidal shape with a small top and a large bottom, and the groove opening is narrower than the bottom. During injection molding, the envelope 3 covers the fixed rib 4 and a small part of the surface of the magnetic tile 2. The structure of the injection groove 5 with a small top and a large bottom can engage the main envelope 3, and can pull the envelope 3 under high speed. The envelope 3 reinforces the magnetic tile 2 by engaging the step groove 2-1 at the end face, ensuring that the magnetic tile 2 will not be thrown off under high speed.

[0036] In order to ensure the magnetic density and magnetic efficiency on the surface of the rotor body 1, it is necessary to ensure the coverage rate of the magnetic tile 2 on the surface of the rotor body 1. Therefore, the arc length angle of the side of the covering surface of the envelope 3 at the contact between the fixed rib 4 and the magnetic tile 2 is 25° to 45°, and the thickness of the envelope is less than 4mm. Too little coverage of the envelope will affect the reinforcement strength of the envelope 3, and too much coverage will affect the effective magnetic density of the magnetic tile 2.

[0037] The surface of the rotor body 1 is provided with a plurality of glue grooves 6 at the bottom joint part of the magnetic tile 2. When the magnetic tile 2 is inserted into the dovetail groove for preliminary fixation, glue can be injected through the glue groove 6 for preliminary fixation to further increase the structural strength.

[0038] In this embodiment, Figure 3 As shown, an injection molding gap 7 is left on one side of the magnetic tile 2 close to the dovetail groove. During injection molding, the injection molding material flows into the injection molding gap 7, that is, when the envelope 3 is formed, there is an envelope wire extending into the injection molding gap 7 under the envelope strip 3-1, thereby increasing the stability of the envelope 3 and increasing the clamping force of the dovetail groove structure on the magnetic tile 2, thereby increasing the firmness of the fixing rib 4, making the fixing rib 4 not easy to break under high rotation speed conditions, and making the rotor structure more stable.

[0039] Embodiment 3: A motor rotor with an envelope 3 comprises a rotor body 1, on which a dovetail groove is provided, in which a magnetic tile 2 is fixed; after the magnetic tile 2 is embedded in the dovetail groove, an envelope 3 is formed around the magnetic tile 2 by injection molding to fix the arc tile-shaped magnetic tile 2 on the rotor body 1.

[0040] The rotor body 1 is cylindrical as a whole, and a plurality of fixing ribs 4 are arranged on the cylindrical side of the rotor body 1, and the upper surface height of the fixing ribs 4 is slightly lower than the upper arc surface of the magnetic tile 2. The fixing ribs 4 slightly lower than the upper surface of the magnetic tile 2 are to leave space for the envelope 3 for injection molding. After the injection molding is completed, the surface of the envelope 3 and the upper arc surface of the magnetic tile 2 are integrally combined to form the outer arc surface of the motor rotor.

[0041] The side of the fixing rib 4 close to the surface of the rotor body 1 is a thin end, and the side of the fixing rib 4 away from the rotor body 1 is a thick end. The adjacent fixing ribs 4 serve as two sides of the dovetail groove, and the dovetail groove is formed between the fixing ribs 4. The dovetail groove performs preliminary positioning of the magnetic tile 2.

[0042] A plurality of injection molding grooves 5 are arranged on the surface of the side of the fixing rib 4 away from the rotor body 1. The cross section of the injection molding groove 5 is a trapezoidal shape with a small top and a large bottom, and the groove opening is narrower than the bottom. The trapezoidal structure design with a small top and a large bottom can form an envelope strip 3-1 with a corresponding structure during injection molding. The envelope strip 3-1 in the accommodation strip is clamped and pulled by the accommodation strip, which increases the binding force of the envelope body 3 on the magnetic tile 2 and the rotor body 1 under high speed conditions, and has a better fixing effect.

[0043] Step grooves 2-1 are provided at both ends of the magnetic tile 2 close to the cylindrical end surface of the rotor body 1, and step grooves 2-1 are provided at both ends of the magnetic tile 2 close to the cylindrical end surface of the rotor body 1. Low-lying beveled areas 2-2 are provided on both sides of the upper arc surface of the magnetic tile 2 close to the fixed rib 4, and the edge of the upper arc surface smoothly sinks in the low-lying beveled area 2-2.

[0044] The envelope body 3 forms an envelope ring 3-2 on the cylindrical end face of the rotor body 1, and the envelope ring 3-2 engages with the step groove 2-1 to fix the magnetic tile 2; the envelope body 3 covers the fixing rib 4 and the low-lying beveled area 2-2 of the magnetic tile 2 to form an envelope strip 3-1, and the surface of the envelope strip 3-1 and the arc surface on the magnetic tile 2 together form the arc surface of the motor rotor. The envelope strip 3-1 covers the magnetic tile 2 in the low-lying beveled area 2-2 of the magnetic tile 2, fixes the magnetic tile 2, and makes the outer arc surface of the motor an integral whole.

[0045] After the magnetic tile 2 is initially fixed in the dovetail groove, the magnetic tile 2 and the rotor body 1 are put into the injection mold for injection molding, and an envelope 3 is formed on the cylindrical end face of the rotor body 1 and the surface of the fixed rib 4, that is, around the magnetic tile 2. The envelope 3 wraps a circle of magnetic tile 2 on the cylindrical end face of the rotor body 1, and engages with the step groove 2-1 for reinforcement; at the same time, a plurality of injection grooves 5 are provided on the surface of the fixed rib 4 away from the rotor body 1. The cross section of the injection groove 5 is a trapezoidal shape with a small top and a large bottom, and the groove opening is narrower than the bottom. During injection molding, the envelope 3 covers the fixed rib 4 and the low-lying bevel area 2-2 of the magnetic tile 2. The structure of the injection groove 5 with a small top and a large bottom can engage the main envelope 3, and can pull the envelope 3 under high speed conditions. The envelope 3 reinforces the magnetic tile 2 by engaging the step groove 2-1 at the end face, ensuring that the magnetic tile 2 will not be thrown off under high speed conditions.

[0046] During the formation of the envelope body 3, the fixing ribs 4 are covered to form an envelope strip 3-1, which is injection molded into the injection molding groove 5. After the injection molding is completed, the envelope strip 3-1 is clamped and fixed by the injection molding groove 5 with a wider bottom and a narrower notch.

[0047] The surface of the magnetic tile 2 is completely exposed, and the envelope 3 only covers the step grooves 2-1 at both ends of the magnetic tile 2 and the connection part between the magnetic tile 2 and the fixing rib 4. Such a design reduces the influence of the envelope 3 on the magnetic efficiency of the magnetic tile 2.

[0048] The surface of the rotor body 1 is provided with a plurality of glue grooves 6 at the bottom joint part of the magnetic tile 2. When the magnetic tile 2 is inserted into the dovetail groove for preliminary fixation, glue can be injected through the glue groove 6 for preliminary fixation to further increase the structural strength.

[0049] The arc length angle of the side of the covering surface of the envelope 3 at the contact point between the fixing rib 4 and the magnetic tile 2 is 25° to 35°. Too small a coverage will affect the reinforcement strength of the envelope 3, and too large a coverage will affect the effective magnetic density of the magnetic tile 2.

[0050] The angle of the chamfer of the side of the dovetail groove is between 40° and 50°. If the chamfer is too large, it is not easy to initially fix the magnetic tile 2. If the chamfer is too large at high speed, the fixed rib 4 will exert less pressure on the magnetic tile 2, and the magnetic tile 2 will easily fly off. If the chamfer is small at high speed, the fixed rib 4 itself cannot withstand the excessive pressure and is prone to breakage, causing motor failure. At the same time, the surface arc length of the wide end of the fixed rib 4 should not be too long, and the number of ribs should not be too many, otherwise the exposed area of ​​the magnetic tile 2 on the motor rotor will be small, affecting the magnetic efficiency of the motor rotor surface.

[0051] In this embodiment, Figure 4As shown, the magnetic tile 2 is also provided with an injection molding chamfer 8 in the low-lying bevel area 2-2. During injection molding, the injection molding material flows into the injection molding chamfer 8, that is, when the envelope 3 is formed, there is an envelope wire extending into the injection molding gap 7 under the envelope strip 3-1. The envelope wire can increase the fixation of the envelope 3 when the rotor rotates at high speed, and at the same time increase the clamping force of the dovetail groove structure on the magnetic tile 2, increase the firmness of the fixing rib 4, make the fixing rib 4 not easy to break under high speed conditions, and make the rotor structure more stable.

[0052] Embodiment 4: A motor rotor with an envelope 3 comprises a rotor body 1, on which a dovetail groove is provided, in which a magnetic tile 2 is fixed; after the magnetic tile 2 is embedded in the dovetail groove, an envelope 3 is formed around the magnetic tile 2 by injection molding to fix the arc tile-shaped magnetic tile 2 on the rotor body 1.

[0053] The rotor body 1 is cylindrical as a whole, and a plurality of fixing ribs 4 are arranged on the cylindrical side of the rotor body 1, and the upper surface height of the fixing ribs 4 is slightly lower than the upper arc surface of the magnetic tile 2. The fixing ribs 4 slightly lower than the upper surface of the magnetic tile 2 are to leave space for the envelope 3 for injection molding. After the injection molding is completed, the surface of the envelope 3 and the upper arc surface of the magnetic tile 2 are integrally combined to form the outer arc surface of the motor rotor.

[0054] The side of the fixing rib 4 close to the surface of the rotor body 1 is a thin end, and the side of the fixing rib 4 away from the rotor body 1 is a thick end. The adjacent fixing ribs 4 serve as two sides of the dovetail groove, and the dovetail groove is formed between the fixing ribs 4. The dovetail groove performs preliminary positioning of the magnetic tile 2.

[0055] A plurality of injection molding grooves 5 are arranged on the surface of the side of the fixing rib 4 away from the rotor body 1. The cross section of the injection molding groove 5 is a trapezoidal shape with a small top and a large bottom, and the groove opening is narrower than the bottom. The trapezoidal structure design with a small top and a large bottom can form an envelope strip 3-1 with a corresponding structure during injection molding. The envelope strip 3-1 in the accommodation strip is clamped and pulled by the accommodation strip, which increases the binding force of the envelope body 3 on the magnetic tile 2 and the rotor body 1 under high speed conditions, and has a better fixing effect.

[0056] Step grooves 2-1 are provided at both ends of the magnetic tile 2 close to the cylindrical end surface of the rotor body 1, and step grooves 2-1 are provided at both ends of the magnetic tile 2 close to the cylindrical end surface of the rotor body 1. Low-lying beveled areas 2-2 are provided on both sides of the upper arc surface of the magnetic tile 2 close to the fixed rib 4, and the edge of the upper arc surface smoothly sinks in the low-lying beveled area 2-2.

[0057] The envelope body 3 forms an envelope ring 3-2 on the cylindrical end face of the rotor body 1, and the envelope ring 3-2 engages with the step groove 2-1 to fix the magnetic tile 2; the envelope body 3 covers the fixing rib 4 and the low-lying beveled area 2-2 of the magnetic tile 2 to form an envelope strip 3-1, and the surface of the envelope strip 3-1 and the arc surface on the magnetic tile 2 together form the arc surface of the motor rotor. The envelope strip 3-1 covers the magnetic tile 2 in the low-lying beveled area 2-2 of the magnetic tile 2, fixes the magnetic tile 2, and makes the outer arc surface of the motor an integral whole.

[0058] After the magnetic tile 2 is initially fixed in the dovetail groove, the magnetic tile 2 and the rotor body 1 are put into the injection mold for injection molding, and an envelope 3 is formed on the cylindrical end face of the rotor body 1 and the surface of the fixed rib 4, that is, around the magnetic tile 2. The envelope 3 wraps a circle of magnetic tile 2 on the cylindrical end face of the rotor body 1, and engages with the step groove 2-1 for reinforcement; at the same time, a plurality of injection grooves 5 are provided on the surface of the fixed rib 4 away from the rotor body 1. The cross section of the injection groove 5 is a trapezoidal shape with a small top and a large bottom, and the groove opening is narrower than the bottom. During injection molding, the envelope 3 covers the fixed rib 4 and the low-lying bevel area 2-2 of the magnetic tile 2. The structure of the injection groove 5 with a small top and a large bottom can engage the main envelope 3, and can pull the envelope 3 under high speed conditions. The envelope 3 reinforces the magnetic tile 2 by engaging the step groove 2-1 at the end face, ensuring that the magnetic tile 2 will not be thrown off under high speed conditions.

[0059] During the formation of the envelope body 3, the fixing ribs 4 are covered to form an envelope strip 3-1, which is injection molded into the injection molding groove 5. After the injection molding is completed, the envelope strip 3-1 is clamped and fixed by the injection molding groove 5 with a wider bottom and a narrower notch.

[0060] The surface of the magnetic tile 2 is completely exposed, and the envelope 3 only covers the step grooves 2-1 at both ends of the magnetic tile 2 and the connection part between the magnetic tile 2 and the fixing rib 4. Such a design reduces the influence of the envelope 3 on the magnetic efficiency of the magnetic tile 2.

[0061] The surface of the rotor body 1 is provided with a plurality of glue grooves 6 at the bottom joint part of the magnetic tile 2. When the magnetic tile 2 is inserted into the dovetail groove for preliminary fixation, glue can be injected through the glue groove 6 for preliminary fixation to further increase the structural strength.

[0062] The arc length angle of the side of the covering surface of the envelope 3 at the contact point between the fixing rib 4 and the magnetic tile 2 is 25° to 35°. Too small a coverage will affect the reinforcement strength of the envelope 3, and too large a coverage will affect the effective magnetic density of the magnetic tile 2.

[0063] The angle of the chamfer of the side of the dovetail groove is between 40° and 50°. If the chamfer is too large, it is not easy to initially fix the magnetic tile 2. If the chamfer is too large at high speed, the fixed rib 4 will exert less pressure on the magnetic tile 2, and the magnetic tile 2 will easily fly off. If the chamfer is small at high speed, the fixed rib 4 itself cannot withstand the excessive pressure and is prone to breakage, causing motor failure. At the same time, the surface arc length of the wide end of the fixed rib 4 should not be too long, and the number of ribs should not be too many, otherwise the exposed area of ​​the magnetic tile 2 on the motor rotor will be small, affecting the magnetic efficiency of the motor rotor surface.

[0064] In this embodiment, Figure 5 As shown, injection-molded fillets 9 are provided at both ends of the magnetic tile 2 near the dovetail groove, and the injection-molded fillets 9 leave a gap between the dovetail groove and the magnetic tile 2. During injection molding, the injection molding material forms a strip-shaped envelope wire in the injection-molded fillet 9, and the envelope wire is pressed and fixed by the magnetic tile 2 and the dovetail groove. At the same time, the envelope ring 3-2 and the envelope strip 3-1 in the envelope body 3 which are integrated with the envelope wire engage the magnetic tile 2 and the fixing rib 4, and clamp the magnetic tile 2 and fix it under high speed. Therefore, the magnetic tile 2, the fixing rib 4 and the envelope body 3 form a complex interlocking structure, which can have better stability when the rotor rotates at high speed, protect the magnetic tile 2 from being easily thrown away, and the fixing rib 4 from being easily broken.

[0065] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A motor rotor with an envelope, characterized in that: It includes a rotor body, which is provided with a dovetail groove composed of fixed ribs, and the magnetic tile is fixed in the dovetail groove; the upper surface height of the fixed rib is lower than the upper arc surface of the magnetic tile; the magnetic tile is embedded in the dovetail groove, and an envelope is provided inside and outside the magnetic tile to fix the magnetic tile and the fixed rib as a whole.

2. The motor rotor with envelope according to claim 1, characterized in that: The rotor body is cylindrical as a whole, and a plurality of fixing ribs are arranged on the cylindrical side of the rotor body, and the upper surface height of the fixing ribs is not higher than the upper arc surface of the magnetic tile.

3. The motor rotor with envelope according to claim 1, characterized in that: The envelope body forms an envelope ring on the cylindrical end face of the rotor body, and the envelope ring engages the step groove to fix the magnetic tile; the envelope body covers the low-lying oblique angle area of ​​the fixed rib and the magnetic tile to form an envelope strip, and the surface of the envelope strip and the arc surface on the magnetic tile together form the arc surface of the motor rotor.

4. The motor rotor with envelope according to claim 1 or 3, characterized in that: An enveloping fixing wire is provided at the place where the enveloping strip covers the fixing rib, and the enveloping fixing wire is embedded in the injection molding groove on the upper surface of the fixing rib, and the enveloping fixing wire is clamped and fixed by the injection molding groove with a wider bottom and a narrower notch.

5. The motor rotor with envelope according to claim 2, characterized in that: The side of the fixing rib close to the surface of the rotor body is a thin end, and the side of the fixing rib away from the rotor body is a thick end. The adjacent fixing ribs serve as two sides of the dovetail groove, and the dovetail groove is formed between the adjacent fixing ribs.

6. The motor rotor with envelope according to claim 5, characterized in that: A plurality of injection molding grooves are arranged on the surface of the fixed rib away from the rotor body. The cross section of the injection molding groove is a trapezoid with a small top and a large bottom, and the groove opening is narrower than the bottom.

7. The motor rotor with envelope according to claim 1, characterized in that: Step grooves are provided at both ends of the magnetic shoe near the cylindrical end surface of the rotor body, and low-lying beveled areas are provided on both sides of the upper arc surface of the magnetic shoe near the fixed ribs, and the edge of the upper arc surface sinks smoothly in the low-lying beveled area.

8. The motor rotor with envelope according to claim 1 or 7, characterized in that: The surface of the magnetic tile is exposed as a whole, and the envelope only seals and wraps the step grooves at both ends of the magnetic tile and the connection part between the magnetic tile and the fixing rib.

9. The motor rotor with envelope according to claim 1 or 2, characterized in that: The surface of the rotor body and the bottom joint part of the magnetic tile are provided with a plurality of rubber storage grooves.

10. The motor rotor with envelope according to claim 1, characterized in that: The side arc length angle of the covering surface of the envelope on the fixed rib and the low-lying oblique angle area of ​​the magnetic tile is between 25 degrees and 45 degrees, and the thickness of the envelope is less than 4mm.

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