CN215374010U

CN215374010U - Magnetic encoder

Info

Publication number: CN215374010U
Application number: CN202121975505.1U
Authority: CN
Inventors: 甘磊; 程云峰; 赵小安; 李文瑞
Original assignee: Servotronix Motion Control Shenzhen Co ltd; Midea Welling Motor Technology Shanghai Co Ltd; Guangdong Midea Intelligent Technologies Co Ltd
Current assignee: Servotronix Motion Control Shenzhen Co ltd; Midea Welling Motor Technology Shanghai Co Ltd; Guangdong Midea Intelligent Technologies Co Ltd
Priority date: 2021-08-20
Filing date: 2021-08-20
Publication date: 2021-12-31
Anticipated expiration: 2031-08-20

Abstract

The utility model discloses a magnetic encoder, which comprises a rotor disc, wherein a plurality of target zero point positions with zero magnetic density are arranged on the magnetic encoder along the circumferential direction of the rotor disc, the rotor disc is provided with a plurality of magnetic pole parts distributed along the circumferential direction, at least part of the magnetic pole parts have different sizes, in two adjacent magnetic pole parts, a magnetic pole neutral surface between the two magnetic pole parts and/or the opposite end surfaces of the two magnetic pole parts are arranged by deviating from the corresponding target zero point positions, so that the actual zero point positions of a magnetic field formed by the plurality of magnetic pole parts are correspondingly positioned at the target zero point positions, the size of each magnetic pole part is reasonably adjusted, the actual zero point position with zero magnetic density of the actual magnetic field of the rotor disc is superposed with the theoretical target zero point position with zero magnetic density of the magnetic field, a magnetic sensor on the stator disc can detect that the actual zero point positions of the magnetic field are more accurate, and the position angle encoding is realized accurately, the measurement accuracy is improved.

Description

Magnetic encoder

Technical Field

The utility model relates to the technical field of encoders, in particular to a magnetic encoder.

Background

An encoder is a device that compiles, converts, and/or formats signals or data into a form of signals that can be communicated, transmitted, and stored. The rotary encoder can directly convert the measured angular displacement into a digital signal, and has wide application in an automatic measurement and control system. However, with the increasing industrial automation degree, higher and higher requirements are put on monitoring parameters including rotation speed, rotation direction and the like, and although some products have the function, the structure is generally complex, the assembly is difficult, the manufacturing cost is high, and the resolution is low.

SUMMERY OF THE UTILITY MODEL

To the defect of traditional encoder, the utility model discloses the people provides a magnetic encoder, need magnetize at the axial to this magnetic encoder, and the problem that magnetic field zero offset can appear, leads to the measuring precision lower, consequently, how to optimize magnetic encoder to it is a problem of waiting to solve urgently to improve the measuring precision.

In order to achieve the above object, the present invention provides a magnetic encoder, which includes a rotor disc, wherein the magnetic encoder is provided with a plurality of target zero point positions where magnetic flux density is zero along a circumferential direction of the rotor disc, the rotor disc is provided with a plurality of magnetic pole portions distributed along the circumferential direction, at least some of the magnetic pole portions are different in size, and in two adjacent magnetic pole portions, a magnetic pole neutral plane between the two magnetic pole portions and/or opposite end faces of the two magnetic pole portions are offset from the target zero point positions, so that actual zero point positions of a magnetic field formed by the plurality of magnetic pole portions are located at the target zero point positions.

Optionally, in the circumferential direction of the rotor disk, the central angle corresponding to the offset between the magnetic pole neutral plane between the two magnetic pole portions and/or the opposite end faces of the two magnetic pole portions and the corresponding target zero point position is α, and-3 ° ≦ α ≦ 3 °.

Optionally, in the circumferential direction of the rotor disk, a central angle between two adjacent target zero-point positions is β, and β ═ δ (i ═ 1, 2, 3.. cndot P, P is the number of the magnetic pole portions), where δ is an allowable error, K is a positive integer, Ni is a positive integer, and Ni < K.

Alternatively, δ ≦ 0.5.

Optionally, the plurality of magnetic pole portions include a plurality of first magnetic pole portions and a plurality of second magnetic pole portions that are arranged in a staggered manner, and each of the first magnetic pole portions and each of the second magnetic pole portions are magnetized in an axial direction and have opposite polarities.

Optionally, the rotor disc has a magnetic ring, and a plurality of magnetic regions are formed on the magnetic ring and distributed along the circumferential direction of the rotor disc to form a plurality of the first magnetic pole parts and a plurality of the second magnetic pole parts.

Optionally, adjacent first and second magnetic pole portions are at least partially connected.

Optionally, a groove is provided at a junction of the first magnetic pole portion and the second magnetic pole portion, and the groove extends in a radial direction of the rotor disk.

Optionally, a nonmagnetic region is provided between the adjacent first magnetic pole part and the second magnetic pole part.

Optionally, the rotor disk has a plurality of magnetic blocks arranged at intervals along the circumferential direction, and each of the magnetic blocks forms a plurality of first magnetic pole parts and a plurality of second magnetic pole parts.

Optionally, a spacer is arranged between the adjacent first magnetic pole part and the second magnetic pole part, and the spacers can be selected to be different in size.

Optionally, it is a plurality of all adopt axial magnetization and polarity the same of magnetic pole portion, it is a plurality of magnetic pole portion interval sets up, and at least part the interval between the magnetic pole portion is inequality.

Optionally, the magnetic encoder further comprises a stator disc, the stator disc is disposed coaxially with the rotor disc and on one side of the rotor disc, which is provided with the magnetic pole portion in the axial direction, the rotor disc is rotatable relative to the stator disc, the stator disc is provided with a plurality of magnetic sensors distributed in the circumferential direction, and the plurality of magnetic sensors are used for generating a sensing signal by sensing a change in a magnetic field.

Optionally, the magnetic sensors are hall sensors, and the hall sensors are uniformly distributed along the circumferential direction.

Optionally, the dimensions of the plurality of magnetic pole portions include a length dimension in a circumferential direction of the rotor disk.

The magnetic encoder is provided with a plurality of target zero positions with zero magnetic density along the circumferential direction of the rotor disc, at least partial magnetic pole parts are different in size, in two adjacent magnetic pole parts, a magnetic pole neutral surface between the two magnetic pole parts and/or two opposite end surfaces of the two magnetic pole parts deviate and are arranged corresponding to the target zero positions, the size of each magnetic pole part is reasonably adjusted, so that the magnetic pole neutral surface between the two magnetic pole parts and/or the two opposite end surfaces of the magnetic pole parts deviate and are arranged corresponding to the target zero positions, further, the actual zero position with zero magnetic density of the actual magnetic field of the rotor disc is coincided with the target zero position with zero magnetic density of the theoretical magnetic field, the actual zero position of the magnetic field detected by the magnetic sensor on the stator disc is accurate, and the position angle encoding is realized accurately, the measurement accuracy is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and those skilled in the art will be able to derive other drawings based on the structures shown in the drawings without creative efforts.

FIG. 1 is a schematic front view of a magnetic encoder according to an embodiment of the present invention;

FIG. 2 is a schematic bottom view of the rotor disk of FIG. 1;

FIG. 3 is a schematic top view of the stator plate of FIG. 1;

FIG. 4 is a schematic diagram of the magnetic flux density of the rotor disk in the circumferential direction and the distribution of the corresponding magnetic pole portions in FIG. 1;

FIG. 5 is a schematic view of the magnet ring of FIG. 1 forming an interface between two adjacent pole pieces;

FIG. 6 is a schematic view of the magnetic ring of FIG. 1 forming a nonmagnetic region between two adjacent magnetic pole portions;

FIG. 7 is a schematic view of the magnetic ring of FIG. 1 with a groove formed between two adjacent pole pieces;

FIG. 8 is a first distribution diagram of the plurality of magnetic blocks of FIG. 1;

FIG. 9 is a second distribution diagram of the plurality of magnetic blocks of FIG. 1;

FIG. 10 is a schematic view of another embodiment of a magnetic encoder in accordance with the present invention.

The reference numbers illustrate:

reference numerals	Name (R)	Reference numerals	Name (R)
				100	Magnetic encoder	15a	Spacer region
1	Rotor disc	2	Stator disc
				11	Magnetic pole part	21	Magnetic sensor
11a	A first magnetic pole part	211	Hall sensor
				11b	Second magnetic pole part	3	Magnetic ring
12a	Target zero position	31	Magnetic region
				13a	Neutral plane of magnetic pole	32	Nonmagnetic region
14a	Groove		4					Magnetic block

The implementation, functional features and advantages of the objects of the present invention will be further explained with reference to the accompanying drawings.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that, if directional indications (such as up, down, left, right, front, and back … …) are involved in the embodiment of the present invention, the directional indications are only used to explain the relative positional relationship between the components, the movement situation, and the like in a specific posture (as shown in the drawing), and if the specific posture is changed, the directional indications are changed accordingly.

In addition, if there is a description of "first", "second", etc. in an embodiment of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In addition, technical solutions between various embodiments may be combined with each other, but must be realized by a person skilled in the art, and when the technical solutions are contradictory or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope of the present invention.

In view of the above, the present invention provides a magnetic encoder, which optimizes the structure of the existing magnetic encoder and improves the measurement accuracy, wherein fig. 1 to 10 are schematic structural diagrams of embodiments of the magnetic encoder provided by the present invention.

Referring to fig. 1 to 4, the magnetic encoder 100 includes a rotor disc 1 and a stator disc 2.

The stator disk 2 is disposed coaxially with the rotor disk 1, and is located on one side of the rotor disk 1, where the magnetic pole portion 11 is disposed in the axial direction, the rotor disk 1 is rotatable relative to the stator disk 2, the stator disk 2 is provided with a plurality of magnetic sensors 21 distributed in the circumferential direction, and the plurality of magnetic sensors 21 are configured to generate a sensing signal by sensing a change in a magnetic field.

That is, when the rotor disc 1 rotates, the magnetic field of the rotor disc 1 changes, and further the magnetic field of the magnetic sensor 21 changes, so that the rotation angle can be obtained by the measurement of the magnetic sensor 21.

The magnetic sensor 21 has high sensitivity and good stability, is convenient to miniaturize and integrate, and can improve the measurement precision.

Further, the rotor disk 1 is provided with a plurality of magnetic pole portions 11 having different sizes, the magnetic pole portions 11 have different coverage areas with respect to the stator disk 2 on the circumference, and when the rotor disk 1 rotates with respect to the stator disk 2, the magnetic sensor 21 measures the magnitude and direction of the magnetic field generated by the rotor disk 1 and converts the magnetic field into an electric signal to calculate the relative rotation angle between the stator disk 2 and the rotor disk 1.

In one embodiment, the magnetic sensor 21 is a hall sensor 211, the hall sensors 211 are uniformly distributed along a circumferential direction, and the hall sensor 211 is a magnetic field sensor manufactured according to a hall effect, and is widely applied to industrial automation technology, detection technology, information processing and the like. In the embodiment of 6 corresponding to the hall sensor 211, the position calculating method of the magnetic encoder 100 includes the following steps:

and comparing the reading of each hall sensor 211 with a preset threshold, if the reading is greater than the threshold, the state of the hall sensor 211 is considered to be 1, and if the reading is less than the threshold, the state of the hall sensor 211 is considered to be 0.

And combining the sensor states according to the states of the 6 Hall sensors 211, so that a gray code area corresponding to the current corner can be obtained through calculation, and each gray code area corresponds to a corner range.

According to the gray code area calculated by the steps and the accurate readings of the 6 hall sensors 211, the accurate relative rotation angle between the stator disc 2 and the rotor disc 1 can be calculated.

The rotor disk 1 is provided with a plurality of magnetic pole portions 11 with different sizes, which may cause a problem of zero-point offset of the magnetic field, resulting in low measurement accuracy, and at this time, the size of each magnetic pole portion 11 needs to be actually adjusted correspondingly, so that an actual zero-point position where the magnetic density of the actual magnetic field is zero coincides with a target zero-point position 12a where the magnetic density of the theoretical magnetic field is zero in the circumferential direction of the rotor disk 1, that is, there is a problem of checking the zero-point offset of the magnetic field.

Specifically, in one embodiment, the magnetic encoder 100 includes a rotor disc 1, the magnetic encoder 100 is provided with a plurality of target zero point positions 12a where the magnetic flux density is zero along the circumferential direction of the rotor disc 1, the rotor disc 1 is provided with a plurality of magnetic pole portions 11 distributed along the circumferential direction, at least a part of the magnetic pole portions 11 are different in size, and in two adjacent magnetic pole portions 11, a magnetic pole neutral surface 13a between the two magnetic pole portions 11 and/or two end surfaces of the magnetic pole portions 11 opposite to each other are arranged in a manner of deviating from the corresponding target zero point positions 12 a.

In the technical solution of the present invention, a plurality of target zero point positions 12a with zero magnetic density are provided on the magnetic encoder 100 along the circumferential direction of the rotor disc 1, at least some of the magnetic pole portions 11 have different sizes, in two adjacent magnetic pole portions 11, a magnetic pole neutral surface 13a between the two magnetic pole portions 11 and/or opposite end surfaces of the two magnetic pole portions 11 are offset from the target zero point positions 12a, and by reasonably adjusting the size of each magnetic pole portion 11, the magnetic pole neutral surface 13a between the two magnetic pole portions 11 and/or the opposite end surfaces of the two magnetic pole portions 11 are offset from the target zero point positions 12a, so that an actual zero point position where the magnetic density of an actual magnetic field of the rotor disc 1 is zero coincides with a target zero point position 12a where the magnetic density of a theoretical magnetic field is zero, and the actual position where the magnetic field is detected by the magnetic sensor 21 on the stator disc 2 can be more accurate, the position angle is accurately encoded, and the measurement precision is improved.

It should be noted that the magnetic pole neutral plane 13a is a plane located in the middle of the two magnetic pole portions 11 in the circumferential direction of the rotor disc 1, that is, a physical middle plane of the structure, and the magnetic pole neutral plane 13a is a radial plane of the rotor disc 1, for example, there is an interface between the two magnetic pole portions 11, that is, the interface is the magnetic pole neutral plane 13 a; a nonmagnetic region 32 is arranged between the two magnetic pole parts 11, and a radial plane where the middle position of the nonmagnetic region 32 is located is a magnetic pole neutral plane 13 a; a dividing region, such as a splicing seam or a breaking cut, is provided between the two magnetic pole portions 11, and a radial plane where a middle position of the splicing seam is located or a radial plane where a middle position of the breaking cut is located is the magnetic pole neutral plane 13 a.

Since the magnetic field size and direction may vary when the plurality of magnetic pole portions 11 are distributed in the circumferential direction of the rotor disk 1, the magnetic field density distribution may be uneven in the circumferential direction of the rotor disk 1, and of course, an actual zero point position at which the magnetic field density is zero may also occur, and the plurality of actual zero point positions may be distributed in the circumferential direction of the rotor disk 1.

In addition, in the embodiment where the polarities of the adjacent magnetic pole portions 11 are opposite and an interface exists between the two magnetic pole portions, the size of the magnetic pole portion 11 needs to be adjusted reasonably so that the magnetic pole neutral plane 13a between the two magnetic pole portions 11 and the opposite end faces of the two magnetic pole portions 11 are both arranged to be deviated from the corresponding target zero point position 12 a; in the embodiment in which the adjacent magnetic pole portions 11 have opposite polarities and a space exists therebetween, the size of the magnetic pole portion 11 needs to be adjusted reasonably so that the magnetic pole neutral plane 13a between the two magnetic pole portions 11 is disposed away from the corresponding target zero point position 12 a; in the embodiment where the adjacent magnetic pole portions 11 have the same polarity and a gap exists therebetween, the size of the magnetic pole portion 11 needs to be adjusted reasonably so that the opposite end faces of the two magnetic pole portions 11 are disposed away from the target zero point position 12 a.

The adjustment of the offset amount is related to the size of the adjacent two magnetic pole parts 11, in one embodiment, in the circumferential direction of the rotor disk 1, the center angle of the magnetic pole neutral plane 13a between the two magnetic pole parts 11 and/or the offset amount between the two opposite end surfaces of the magnetic pole parts 11 and the corresponding target zero point position 12a is alpha, and alpha is greater than or equal to-3 degrees and less than or equal to 3 degrees.

That is, the offset between the magnetic pole neutral surface 13a between the two magnetic pole portions 11 and/or the end surface of the two magnetic pole portions 11 opposite to the target zero point position 12a is less than 3 °, and within this range, the relative size of the magnetic pole portions 11 is reasonably adjusted, so that the actual zero point position where the magnetic density of the actual magnetic field of the rotor disc 1 is zero coincides with the target zero point position 12a where the magnetic density of the theoretical magnetic field is zero, and the magnetic sensor 21 on the stator disc 2 can detect the target zero point position 12a of the magnetic field accurately, thereby realizing accurate position angle coding and improving the measurement accuracy.

Specifically, in one embodiment, referring to fig. 4, in the circumferential direction of the rotor disk 1, a central angle between two adjacent target zero point positions 12a is β, and β °/K ± δ (i is 1, 2, 3.. said P is the number of the magnetic pole portions), where δ is an allowable error, K is a positive integer, Ni is a positive integer, and Ni < K.

Namely, a certain incidence relation exists between two adjacent zero point positions 12a, so that the size of each magnetic pole part 11 can be adjusted uniformly, the adjustment amount can also show a certain rule, and quick adaptation and adjustment are facilitated.

The values of N and K may be reasonably adjusted as needed, for example, in one embodiment, K is 36, and Ni is 3, so that the central angle between two adjacent target zero positions 12a is 30 °; k is 72, Ni is 5, the center angle between two adjacent target zero positions 12a is 25 °, and so on.

In addition, δ is a manufacturing tolerance, and in one embodiment, δ ≦ 0.5 °, it is more convenient to adjust the size of the magnetic pole portion 11 in consideration of the manufacturing tolerance.

In the embodiment of the present invention, the size specification of the magnetic pole portion 11 is not limited, for example, the width dimension in the radial direction of the rotor disk 1 may be used, or the length dimension in the circumferential direction of the rotor disk 1 may be used, and in order to facilitate adjustment of the magnetic pole portion 11, the width dimension of the magnetic pole portion 11 in the radial direction of the rotor disk 1 is set to be uniform, and only the length dimension of the magnetic pole portion 11 in the circumferential direction of the rotor disk 1 needs to be adjusted, so that rapid adjustment is facilitated.

In an embodiment of the present invention, without limiting the specific distribution form of the magnetic pole portions 11, in an embodiment, referring to fig. 5 to 7, the plurality of magnetic pole portions 11 include a plurality of first magnetic pole portions 11a and a plurality of second magnetic pole portions 11b that are arranged in a staggered manner, and each of the first magnetic pole portions 11a and each of the second magnetic pole portions 11b are magnetized in an axial direction and have opposite polarities.

That is, first magnetic pole portion 11a with second magnetic pole portion 11b one is the N utmost point, and another is the S utmost point, rotor disc 1 is distributing the N utmost point and the S utmost point of crisscross setting on the circumference, because it is a plurality of first magnetic pole portion 11a and a plurality of in the second magnetic pole portion 11b, there is some the size of first magnetic pole portion 11a is different, or there is some the size of second magnetic pole portion 11b is not the same, or there is some first magnetic pole portion 11a and some the size of second magnetic pole portion 11b is different, or above condition all exists, therefore N utmost point and S utmost point are uneven distribution on the circumference of rotor disc 1, specifically, magnetic sensor 21 outputs alternating signal, can accurate sensing state.

In the above embodiment, the magnetic ring 3 may be used for magnetization, or the magnetic block 4 may be used for magnetization, specifically, in the embodiment that the magnetic ring 3 is used for magnetization, the rotor disk 1 has the magnetic ring 3, and a plurality of magnetic regions 31 distributed along the circumferential direction of the rotor disk 1 are formed on the magnetic ring 3 to form a plurality of the first magnetic pole portions 11a and a plurality of the second magnetic pole portions 11b, so that only a single magnetic ring 3 needs to be manufactured and the magnetic ring 3 needs to be charged with magnetism.

Referring to fig. 5, a sharp magnetic pole interface between two adjacent magnetic pole portions 11 can be achieved by using a precise magnetizing process, however, in most cases, when the magnetic ring 3 is magnetized, a magnetic field mixing condition occurs at the interface, that is, the magnetic pole interface between the adjacent first magnetic pole portion 11a and the adjacent second magnetic pole portion 11b is not clear enough. Therefore, the groove can be formed in the physical shape of the magnetic ring, the occurrence of mixed magnetism can be reduced, and the magnetic interface is relatively clear.

Further, referring to fig. 7, a groove 14a is disposed at a junction of the first magnetic pole portion 11a and the second magnetic pole portion 11b, the groove 14a extends along a radial direction of the rotor disc 1, that is, after the magnetization is completed, the groove 14a is formed on the magnetic ring 3 by cutting, or the groove 14a is formed before the magnetization, and by the arrangement of the groove 14a, a magnetic mixing area between the two magnetic pole portions 11 with different polarities is reduced, so that magnetic density distribution in a circumferential direction of the rotor disc 1 is better.

It should be noted that the size of the groove 14a is not limited, for example, the depth of the groove 14a may be 1/3, 1/4, 1/5, etc. of the thickness of the magnetic pole part 11, and the shape is not limited, for example, square, semi-circular arc, etc.

Referring to fig. 6, in another embodiment, a non-magnetic region 32 is disposed between the first magnetic pole part 11a and the second magnetic pole part 11b that are adjacent to each other, that is, the non-magnetic region 32 reduces the magnetic mixing area between the two magnetic pole parts 11 with different polarities, so that the magnetic density distribution of the rotor disk 1 in the circumferential direction is better.

In another embodiment, referring to fig. 8 to 9, the rotor disk 1 has a plurality of magnetic blocks 4 arranged at intervals along the circumferential direction, and each of the magnetic blocks 4 forms a plurality of the first magnetic pole portions 11a and a plurality of the second magnetic pole portions 11 b.

Namely, the plurality of magnetic blocks 4 are respectively formed by machining and then are mounted on the rotor disc 1 to respectively form the plurality of first magnetic pole parts 11a and the plurality of second magnetic pole parts 11b, so that the magnetizing process is simplified, the magnetic field boundary at the junction between the adjacent first magnetic pole parts 11a and the adjacent second magnetic pole parts 11b is obvious, the magnetic field distortion is reduced, and the magnetic flux density distribution in the circumferential direction of the rotor disc 1 is better.

In one embodiment, a space 15a is provided between the adjacent first magnetic pole part 11a and the second magnetic pole part 11b, and a distance between two magnetic blocks 4 is not limited, for example, referring to fig. 8, a distance between two magnetic blocks 4 is relatively large and is a large notch; in addition, referring to fig. 9, the relative distance between the two magnetic blocks 4 is small, and is a splicing seam, that is, the two magnetic blocks 4 are laterally abutted together, and in both embodiments, the distance between the two magnetic blocks 4 can be adjusted according to actual needs.

In other embodiments, referring to fig. 10, all of the magnetic pole portions 11 are magnetized in the axial direction and have the same polarity, that is, the magnetizing directions are the same, the magnetic pole portions 11 are arranged at intervals, and at least some of the magnetic pole portions 11 have different intervals. That is, the magnetic poles are distributed on the whole circumference as single magnetic poles, and the polarity of each magnetic pole part 11 is N pole or S pole. Compared with the method of arranging two magnetic poles, the method can be understood that the corresponding S pole or N pole is subjected to the blank processing, and the length of the blank position, namely the length of the corresponding magnetic pole part 11, so that the overall principle of position decoding of the magnetic sensor 21 is not influenced, and the material is saved. In this configuration, the single magnetic pole is disposed in a manner that there is no absolute magnetic pole neutral plane after the magnetic field is formed, so that the signal processing is different, and a detailed description thereof is omitted.

The above description is only an alternative embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications and equivalents of the present invention, which are made by the contents of the present specification and the accompanying drawings, or directly/indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. The utility model provides a magnetic encoder, its characterized in that, magnetic encoder includes the rotor dish, magnetic encoder follows be equipped with a plurality of magnetic densities in the circumference of rotor dish and be the zero position of target, the rotor dish is provided with along a plurality of magnetic pole portions that circumference distributes, at least part the size of magnetic pole portion is inequality, adjacent two in the magnetic pole portion, two magnetic pole neutral plane and/or two between the magnetic pole portion the relative terminal surface of magnetic pole portion deviates and corresponds the zero position of target sets up, so that a plurality ofly the actual zero position of the magnetic field that magnetic pole portion formed corresponds and is in zero position of target department.

2. The magnetic encoder according to claim 1, wherein a center angle corresponding to an amount of offset between a pole neutral plane between two of the magnetic pole portions and/or opposing end faces of the two magnetic pole portions and the corresponding target zero point position in the circumferential direction of the rotor disk is α, and-3 ° ≦ α ≦ 3 °.

3. The magnetic encoder according to claim 1, wherein a central angle between two adjacent target zero positions in a circumferential direction of the rotor disk is β, and β ± δ is a number, where δ is an allowable error, K is a positive integer, Ni is a positive integer, and Ni < K.

4. The magnetic encoder of claim 3, wherein δ ≦ 0.5 °.

5. The magnetic encoder of claim 1, wherein the plurality of magnetic pole portions comprises a plurality of first magnetic pole portions and a plurality of second magnetic pole portions arranged in a staggered manner, and wherein each of the first magnetic pole portions and each of the second magnetic pole portions are axially magnetized with opposite polarities.

6. The magnetic encoder as claimed in claim 5, wherein the rotor disk has a magnetic ring formed with a plurality of magnetic regions distributed along a circumferential direction of the rotor disk to form a plurality of the first magnetic pole portions and a plurality of the second magnetic pole portions.

7. The magnetic encoder of claim 6, wherein adjacent first and second magnetic pole portions are at least partially connected.

8. The magnetic encoder as claimed in claim 7, wherein a groove is provided at an intersection of the first magnetic pole part and the second magnetic pole part, the groove extending in a radial direction of the rotor disk.

9. The magnetic encoder of claim 6, wherein a nonmagnetic region is disposed between adjacent first and second magnetic pole portions.

10. The magnetic encoder of claim 5, wherein the rotor disk has a plurality of magnetic blocks spaced apart in a circumferential direction, each of the magnetic blocks forming a plurality of the first magnetic pole portions and a plurality of the second magnetic pole portions, respectively.

11. The magnetic encoder as claimed in claim 10, wherein a spacer is provided between the adjacent first and second magnetic pole portions, the spacers being selected to have different sizes.

12. The magnetic encoder of claim 1, wherein the plurality of magnetic pole portions are axially magnetized and have the same polarity, and the plurality of magnetic pole portions are spaced apart and at least some of the magnetic pole portions have different spacing.

13. The magnetic encoder according to claim 1, further comprising a stator disk disposed coaxially with the rotor disk on a side of the rotor disk in the axial direction on which the magnetic pole portion is disposed, the rotor disk being rotatable relative to the stator disk, the stator disk being provided with a plurality of magnetic sensors distributed in a circumferential direction for generating a sensing signal by sensing a change in a magnetic field.

14. The magnetic encoder of claim 13, wherein the magnetic sensor is a hall sensor, and a plurality of the hall sensors are evenly distributed along a circumferential direction.

15. The magnetic encoder of claim 1, wherein the dimensions of the plurality of magnetic pole portions include a length dimension in a circumferential direction of the rotor disk.