CN206135586U - Permanent -magnet machine rotor structure and permanent -magnet machine - Google Patents

Abstract

The utility model discloses a rotor structure of a permanent magnet motor and a permanent magnet motor, wherein the rotor structure of the permanent magnet motor includes an iron core and a permanent magnet, the iron core includes an annular ring provided with a central shaft hole, and the outer side of the annular ring protrudes A plurality of magnetic permeable blocks are formed, grooves for installing magnetic steel are formed between adjacent magnetic permeable blocks, and bosses are set on the outer edge of the annular ring between adjacent magnetic permeable blocks so that the After the magnetic steel is installed, it is supported by the boss, and the shape of the magnetic steel is trapezoidal in the radial direction, and the length of one end near the direction of the annular ring is greater than the other end; the permanent magnet motor includes a stator and the above permanent magnet Motor rotor structure. According to the permanent magnet motor rotor structure and the permanent magnet motor realized by the utility model, the structure is simple, the processing is convenient, the flux leakage is small, the strength is high, and the torque and power density of the motor can be improved.

Description

A permanent magnet motor rotor structure and permanent magnet motor

technical field

The utility model belongs to the technical field of permanent magnet motors, and more specifically relates to a permanent magnet motor rotor structure and a permanent magnet motor.

Background technique

The traditional permanent magnet brushless DC or synchronous motor rotor structure mostly adopts the surface-mounted magnetic steel structure, and the motor with the built-in magnetic steel structure has attracted much attention because it can use the reluctance torque to further increase the output torque. In particular, the tangential magnetization structure can realize the parallel connection of two adjacent magnetic steels to provide magnetic flux, which significantly improves the air gap flux and increases the rated output torque and output power of the motor. However, there is a mechanical strength of the rotor punching in practical applications The contradiction between magnetic flux leakage and magnetic steel leakage, in order to reduce the magnetic flux leakage of the magnetic steel, the magnetic isolation bridge should be as narrow as possible, and the magnetic bridge that is too narrow will cause the punching sheet to be difficult to process, the mechanical strength of the rotor is poor, and the production cost will increase, while the magnetic isolation bridge The existence of provides a path for the leakage flux, and it should not be too wide, otherwise the performance of the motor will be significantly reduced.

In the general built-in tangentially magnetized rotor core punching sheet, as shown in Figure 1, the outer side of the central axis hole 11 is the rotor yoke 21, and the grooves 31 for installing magnetic steel are evenly distributed on the punching sheet, and the grooves 31 are close to The bottom of the rotor yoke is composed of three sections of broken lines, and the retaining hooks 51 protrude from the magnetic blocks on both sides of the opening. is the center of the circle. This structure uses the notch stop hook in the groove and the broken line at the bottom of the groove to position the magnet steel. The air groove at the bottom of the groove plays a certain role in magnetic isolation, but there is a large magnetic flux leakage of the rotor core and a relatively large torque ripple. advanced questions. Patents CN201601540U and CN104037965A disclose a method of reducing magnetic flux leakage by opening a number of air isolation grooves/grooves on the rotor iron core punching sheet. Magnetic inhibition is also limited. Patent CN103730969A discloses a method of reducing magnetic flux leakage by using a non-magnetic support frame, and provides a related installation method, but the use of pieced rotor punching will lead to stress concentration at the narrowest part of the dovetail notch punching, The difficulty of rotor stamping processing increases. Patents CN202221930U and CN203387314U disclose a rotor structure that uses a protruding magnetic block in the groove to reduce the magnetic flux leakage of the magnetic steel, but the magnetic flux leakage is still relatively obvious according to the given embodiment, and the groove opening of the magnetic steel is placed The retaining hook at the place also needs to be checked for strength. Patent CN204559270U discloses a method of using non-magnetic material to press-fit the magnetic steel in the groove, but the use of the outer bushing of the rotor increases the air gap of the motor, which will lead to the loss of motor performance. Patent CN205453334U discloses a rotor structure applied to brushless DC motors, which uses a method similar to a protruding magnetic block to reduce the magnetic flux leakage of the rotor yoke, and uses injection molding to improve the strength of the rotor, but the opening of the groove Flux leakage is still not well resolved.

The existing technology mainly starts from the magnetic bridge, and reduces the magnetic flux leakage by reducing the width of the magnetic bridge or increasing the air isolation groove, but it is difficult to achieve good mechanical strength so that the rotor punch becomes fragile, and the processing It is very difficult; although the retaining hook at the opening of the groove can play a role in fixing the magnet, it will increase the flux leakage, and it is difficult to guarantee the mechanical strength during high-speed operation, which may cause various problems such as the throwing of the magnet.

Utility model content

In view of the above defects or improvement needs of the prior art, the utility model provides a trapezoidal magnetic steel built-in tangential magnetization machine with simple structure, convenient processing, less magnetic flux leakage, high strength, and can improve the torque and power density of the motor. A permanent magnet motor rotor structure and a motor with the rotor structure.

In order to achieve the above object, according to one aspect of the utility model, a permanent magnet motor rotor structure is provided, including an iron core and a permanent magnet. The iron core includes an annular ring with a central axis hole, and the outer side of the annular ring protrudes to form A plurality of magnetic permeable blocks, a groove for installing magnetic steel is formed between adjacent magnetic permeable blocks, and a boss is set on the outer edge of the annular ring between adjacent magnetic permeable blocks so that the After the magnetic steel is installed, it is supported by the boss, and the shape of the magnetic steel is trapezoidal along the radial direction, and the length of one end close to the annular ring direction is longer than the other end.

Further, the outer edge of the magnetic permeable block is arc-shaped.

Further, there is a magnetic isolation bridge with a width of no more than 1 mm in the circumferential tangential direction between the magnetic permeable block and the annular ring.

Further, the radial width of the annular ring is no more than 1 mm.

Further, the outer arc line of the magnetic permeable block is an arc line centered at a point offset by a certain distance H from the center of the shaft.

The utility model also discloses a permanent magnet motor, which is characterized in that it includes a stator and a rotor, wherein the rotor structure is the above rotor structure.

Further, the motor is an inner rotor permanent magnet motor.

Further, the motor stator winding adopts fractional slot concentrated winding.

Generally speaking, compared with the prior art, the above technical solutions conceived by the utility model can achieve the following beneficial effects:

(1) The rotor punch adopts a trapezoidal magnetic steel structure, and the retaining hook at the groove opening is removed, which effectively reduces the magnetic flux leakage of the motor, improves the utilization rate of the magnetic steel, improves the mechanical strength of the rotor punch, and increases the pole arc of the motor , improving motor performance.

(2) The rotor yoke is provided with a boss to realize the positioning of the magnetic steel, and the air groove between the boss and the magnetic bridge effectively limits the magnetic flux leakage without losing the mechanical strength.

(3) The rotor punching process and assembly are simple, and mass production can be realized economically.

Description of drawings

Fig. 1 is a schematic diagram of a motor structure realized according to the prior art;

Fig. 2 is a schematic diagram of the motor structure realized according to the utility model;

Fig. 3 is the schematic diagram of the iron core structure realized according to the utility model;

Fig. 4 is a schematic diagram of the motor structure of the rotor structure realized according to the utility model;

Fig. 5 is a schematic diagram of the principle of adopting eccentric circles for the outer arc of the rotor stamping realized according to the utility model.

Throughout the drawings, the same reference numerals are used to designate the same elements or structures, wherein:

11-Central shaft hole 21 of the iron core punch in the prior art-rotor yoke 31 of the iron core punch in the prior art-magnetic steel groove 41 in the prior art-magnetic conduction in the prior art Block 51 - the outer edge of the magnetic permeable block 41 in the prior art 61 - the outer edge of the magnetic permeable block 41 in the prior art

12-Central shaft hole of iron core punching sheet 22-Rotor annular ring 42-Magnetic block in this application 71-Magnetic isolation bridge 81-Boss 91-Magnet 10-Stator punching sheet

detailed description

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute conflicts with each other.

Specifically, as shown in Figures 2 and 3, the trapezoidal magnetic steel structure described in the present invention has a built-in tangentially magnetized permanent magnet motor rotor structure.

As shown in Figure 2, it includes an iron core and a magnetic steel 91. The iron core includes an annular ring 22 provided with a central axis hole 12 and several magnetic permeable blocks 42 protruding from the outside of the annular ring 22. Two adjacent magnetic permeable blocks 42 A radial trapezoidal groove for installing the magnetic steel 91 is formed therebetween, and the cross-sectional shape of the outer surface of the magnetic permeable block 42 is an arc line. The annular ring 22, the magnetic bridge 71, the boss 81 and the magnetic block 42 together constitute the rotor stamping sheet as shown in Figure 3, the material of the rotor stamping sheet is silicon steel sheet, the magnetic steel 91 is made of NdFeB material, and adjacent The magnetic steel is magnetized in the opposite direction.

In the embodiment of applying the rotor structure of the present utility model, as shown in Figure 4, the stator punching sheet 10 is a silicon steel sheet material, the stator winding is a fractional slot concentrated winding, the rotor punching sheet equipped with magnetic steel 91 is a moving part, and the stator punching sheet 10 is a moving part. The rotor is concentric, and there is an air gap with a thickness of 0.6mm between the stator and the rotor. The width of the rotor annular ring 22 , the width of the boss 81 and the width of the magnetic bridge 71 are all 1 mm, which can be smaller in consideration of processing capacity and mechanical strength. The width of the bottom of the magnetic steel 91 close to the shaft hole 12 is 4mm, and the width close to the notch is 3mm. The trapezoidal shape can be used to fix the magnetic steel even when running at high speed. The bottom width is less than 6.6mm in the embodiment, so increase the bottom width Can improve motor performance. On this basis, the center of the outer circular arc of the magnetic permeable block 42 is set at the center H away from the axis, which is 7 mm in the embodiment, as shown in Figure 5, which can further reduce the cogging torque and reduce the torque ripple .

Wherein, on the basis of the above arrangement structure, the width of the annular ring 22 outside the central shaft hole 12 in the radial direction is not more than 1mm.

Wherein, the width of the magnetic isolation bridge 71 connecting the magnetic permeable block 42 and the annular ring 22 on the rotor punching piece in the tangential direction of the circumference is not more than 1 mm.

The shape of the magnetic steel 91 is trapezoidal, and the width of the bottom near the central shaft hole is larger than the width near the air gap side. The bottom width of the magnetic steel 91 near the central shaft hole should be as wide as possible under the premise of meeting the processing requirements. On the one hand, the area for providing magnetic flux increases, and on the other hand, it is very important that the magnetic steel will not be thrown out during the rotation of the rotor while removing the retaining hook of the magnetic steel notch, which is in this type of small and medium-sized motors. It is a very important factor that limits the performance of the motor. The width of the bottom should be as wide as possible under the premise of processing, mainly to increase the area of magnetic flux provided by the magnetic steel. Under the same axial length, the hypotenuse of the trapezoid is larger than that of the trapezoid. High (in the case of a rectangle), the magnetic flux increases, and the no-load back EMF and output torque are improved.

Wherein, further, the outer arc line of the magnetic permeable block 42 can use the point O1 offset by a certain distance H from the center of the shaft hole as the center to reduce the cogging torque, as shown in FIG. 5 .

Furthermore, the magnetic field of each pole of the trapezoidal magnetic steel built-in tangentially magnetized rotor structure is provided by two magnetic steels 91 connected in parallel. Those skilled in the art can easily understand that the above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications, equivalent replacements and modifications made within the spirit and principles of the utility model Improvements and the like should all be included within the protection scope of the present utility model.

Claims (8)

1. a kind of rotor structure for permanent magnet motor, including iron core and permanent magnet, iron core includes being provided with the annular ring of central shaft hole (22), annular ring (22) outside protrusion forms some pieces of magnetic inductive blocks (42), and being formed between the adjacent magnetic inductive block is used for The groove of mounting magnetic steel (91), the outer of the annular ring (22) between the adjacent magnetic inductive block arranges boss (81) and causes Supported by the boss (81) after the magnet steel (91) is mounted, and the magnet steel (91) is shaped as radially in ladder Shape, length one end near annular ring (22) direction is more than other end.

2. rotor structure for permanent magnet motor as claimed in claim 1, it is characterised in that the outer of the magnetic inductive block (42) is circular arc Type.

3. rotor structure for permanent magnet motor as claimed in claim 1 or 2, it is characterised in that the magnetic inductive block (42) and the ring Between shape circle for a circumference tangential direction width less than 1mm every magnetic bridge (71).

4. rotor structure for permanent magnet motor as claimed in claim 3, it is characterised in that the radial width of annular ring (22) is not More than 1mm.

5. rotor structure for permanent magnet motor as claimed in claim 2, it is characterised in that the outer arc line of the magnetic inductive block (42) It is the circular arc line with the point of offset axis center certain distance H as the center of circle.

6. a kind of magneto, it is characterised in that it includes stator and rotor, the wherein rotor structure are in claim 1-5 Rotor structure described in any one.

7. magneto as claimed in claim 6, it is characterised in that the motor is internal rotor permanent magnet motor.

8. magneto as claimed in claim 7, it is characterised in that the motor stator winding using fractional-slot concentrate around Group.