Coaxial magnetic gear optical incremental encoder

Abstract

The utility model discloses a coaxial magnetic gear optical incremental encoder, which relates to the technical field of magnetic gears and comprises a motor shell and a mechanical rotating shaft in the motor shell, a bearing and a photoelectric coded disc are distributed on the mechanical rotating shaft, the photoelectric coded disc comprises a coaxial magnetic gear, and the coaxial magnetic gear sequentially comprises an inner rotor, a magnetic adjusting ring and an outer rotor from inside to outside. The inner rotor is fixed on the mechanical rotating shaft, inner rotor permanent magnets are distributed on the outer ring of the inner rotor, the magnetizing directions of the adjacent inner rotor permanent magnets are opposite, outer rotor permanent magnets are distributed on the inner ring of the outer rotor, and the magnetizing directions of the adjacent outer rotor permanent magnets are opposite; the number of pole pairs of the inner rotor permanent magnets is not equal to that of pole pairs of the outer rotor permanent magnets. Gaps are formed between the magnetism adjusting ring and the inner rotor and the outer rotor. And a plurality of square slotted holes are uniformly distributed on the outer ring of the outer rotor. According to the utility model, the speed of the optical incremental encoder is accelerated, the signal transmission is more efficient and accurate, the signal quality is improved, and the optical incremental encoder is not easy to interfere.

Description

TECHNICAL FIELD

[0001] The utility model relates to magnetic gear technical field, especially a coaxial magnetic gear optical type incremental encoder. BACKGROUND

[0002] An encoder is a device that converts angular displacement into electrical signals through a code disc or converts linear displacement into electrical signals through a code ruler. The advantages of an encoder include: it can improve the transmission speed of data and reduce the latency of information; it can also enhance the security of data. However, the encoder also has some non-negligible disadvantages, such as: it can cause some loss to the quality of data, and the cost of processing data is relatively high. Encoders can be generally divided into contact and non-contact types according to their output methods. A non-contact encoder mainly uses optical elements such as photoresistors and photodiodes, or magnetic elements such as magnetoresistive elements and magnetic diodes. In addition, encoders can also be divided into incremental and absolute types according to their working principles. An incremental encoder mainly uses light sources, photoelectric sensors, and photoelectric code discs with multiple equal-width and equal-interval transparent parallel slits.

[0003] An incremental encoder is a device that converts displacement into periodic electrical signals. It detects the changes in the slits on the grating through a photoelectric sensor and converts these light changes, i.e., optical signals, into electrical signals, thereby displaying the changes in the movement and position of the device. The advantages of an incremental encoder include simple structure, long mechanical average life, easy installation, long service life, etc. However, it also has some problems, such as being sensitive to environmental interference, requiring attention to anti-interference, limited trial range, and possible errors in information due to long time. Currently, incremental encoders are widely used, mainly including optical incremental encoders (photoelectric encoders), magnetic incremental encoders (Hall encoders), and mechanical encoders.

[0004] Among them, the optical incremental encoder has a simple principle structure, can provide high resolution, has long mechanical life, and is low in cost, and is suitable for applications requiring high-precision measurement and servo control systems. However, the optical incremental encoder is limited in speed, resulting in insufficient running speed; the transmitted signal is not efficient, not accurate, and has poor signal quality, is easily disturbed, etc.

[0005] A traditional magnetic gear motor is a device that uses magnetic force to rotate without mechanical contact. Its main advantages include overload protection, no need for lubrication, high reliability, long service life, no friction, smooth rotation, etc. However, the traditional magnetic gear motor has a small rotating torque and is easily affected by changes in the surrounding environment such as temperature and external magnetic field.

[0006] The coaxial magnetic gear motor mainly comprises an inner rotor, an outer rotor, inner and outer rotor permanent magnets and a magnetic adjusting ring. SUMMARY

[0007] The coaxial magnetic gear optical incremental encoder provided by the utility model overcomes the defects of the prior art and has the advantages that the coaxial magnetic gear motor is added to the optical incremental encoder, the motor can improve the speed, the signal transmission is more efficient and accurate, the signal quality is improved, and the optical incremental encoder is not easily disturbed.

[0008] The utility model discloses a technical scheme that solves the above technical problems:

[0009] The coaxial magnetic gear optical incremental encoder comprises a motor shell, a mechanical rotating shaft in the motor shell and a photoelectric encoder disc distributed on the mechanical rotating shaft.

[0010] The inner rotor is fixed on the mechanical rotating shaft, the outer ring of the inner rotor is provided with inner rotor permanent magnets, the magnetization directions of two adjacent inner rotor permanent magnets are opposite, the inner ring of the outer rotor is provided with outer rotor permanent magnets, the magnetization directions of two adjacent outer rotor permanent magnets are opposite, the number of pole pairs of the inner rotor permanent magnets is not equal to the number of pole pairs of the outer rotor permanent magnets, and there is a gap between the magnetic adjusting ring and the inner rotor and the outer rotor.

[0011] The outer ring of the outer rotor is uniformly provided with a plurality of square grooves.

[0012] As a further optimization scheme of the coaxial magnetic gear optical incremental encoder, the magnetic adjusting ring is a double-bridge type magnetic adjusting ring, the double-bridge type magnetic adjusting ring comprises a plurality of magnetic adjusting core blocks connected in series, the connecting part between the magnetic adjusting core blocks comprises an upper groove and a lower groove, the upper groove is close to the outer rotor permanent magnets, the lower groove is close to the inner rotor permanent magnets, the upper groove and the lower groove are not equal in size, and the number of the magnetic adjusting core blocks is equal to the number of pole pairs of the inner rotor permanent magnets plus the number of pole pairs of the outer rotor permanent magnets.

[0013] As a further optimization scheme of the coaxial magnetic gear optical incremental encoder, the size of the upper groove is twice that of the lower groove.

[0014] As a further optimization scheme of the coaxial magnetic gear optical incremental encoder, there is an air gap between the upper groove of the magnetic adjusting ring and the outer rotor permanent magnet, which is called an outer layer air gap; there is an air gap between the lower groove of the magnetic adjusting ring and the inner rotor permanent magnet, which is called an inner layer air gap.

[0015] As a further optimization scheme of the coaxial magnetic gear optical incremental encoder, the square slot holes are consistent in size.

[0016] As a further optimization scheme of the coaxial magnetic gear optical incremental encoder, the inner rotor permanent magnet and the outer rotor permanent magnet are annular permanent magnets.

[0017] As a further optimization scheme of the coaxial magnetic gear optical incremental encoder, the surfaces of the outer rotor permanent magnet and the inner rotor permanent magnet are coated with metal glue.

[0018] As a further optimization scheme of the coaxial magnetic gear optical incremental encoder, a plurality of square centripetal light transmission slits consistent in size are distributed on the edge of the photoelectric encoder disc, the centripetal light transmission slits are equidistant on the circumference of the photoelectric encoder disc, and the rest of the photoelectric encoder disc is not light-transmitting.

[0019] As a further optimization scheme of the coaxial magnetic gear optical incremental encoder, the surface of the rest of the photoelectric encoder disc is plated with metal chromium.

[0020] As a further optimization scheme of the coaxial magnetic gear optical incremental encoder, it further comprises a light-emitting diode, a convex lens, a light barrier plate, a photosensitive tube and an Amp amplifier, wherein the convex lens is distributed in front of the photoelectric encoder disc, the light-emitting diode is arranged in front of the convex lens, the light barrier plate is distributed behind the photoelectric encoder disc, a plurality of square slits are distributed on the light barrier plate, the photosensitive tube is arranged behind the light barrier plate, the photosensitive tube is used for converting optical signals into electrical pulse signals, the photosensitive tube is connected with the Amp amplifier behind the photoelectric encoder disc, and the Amp amplifier is used for amplifying the electrical pulse signals and then outputting the amplified electrical pulse signals.

[0021] Compared with the prior art, the coaxial magnetic gear optical incremental encoder has the following technical effects:

[0022] (1) The outer rotor is provided with a plurality of square slot holes, which can better capture the light energy transmitted by the light-emitting diode, accelerate the transmission of optical signals, expand the range of optical signal transmission, and improve signal quality. In addition, these square slot holes promote air circulation and enhance air flow, thereby achieving an effective heat dissipation function.

[0023] (2) The magnetic adjusting ring adopts a double-bridge type structure, and each magnetic adjusting core block is connected between the upper and lower parts, and the upper and lower parts are respectively provided with two unequal grooves, which effectively improve the efficiency of the motor, reduce energy and electromagnetic loss, and weaken the interference of the coaxial magnetic gear motor on the optical incremental encoder, improve the speed of the optical incremental encoder, and further improve the function.

[0024] (3) A layer of metal glue is coated on the permanent magnet, so that a protective film is formed on the surface of the permanent magnet, thereby prolonging the service life, reducing noise and vibration, and compensating for the small defects of the permanent magnet, enhancing the magnetic field strength, and further increasing the output power and efficiency of the optical incremental encoder signal.

[0025] (4) The utility model discloses a novel magnetic gear optical incremental encoder which has low manufacturing cost, fast heat dissipation, small interference to surrounding equipment, high efficiency, fast operation speed and high efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is the structural schematic diagram of the magnetic gear optical incremental encoder of the utility model;

[0027] Figure 2 is the internal structure schematic diagram of the coaxial magnetic gear designed by the utility model.

[0028] The reference signs in the drawings are explained as follows:

[0029] 1-mechanical rotating shaft, 2-bearing, 3-coaxial magnetic gear, 4-uniformly distributed light transmission groove, 5-optoelectronic encoder, 6-light emitting diode, 7-convex lens, 8-light barrier plate, 9-photosensitive tube, 10-Amp amplifier, 11-sheath, 12-motor housing, 30-outer rotor slot hole, 31-inner rotor, 32-inner rotor permanent magnet, 33-inner layer air gap, 34-inner layer air gap groove, 35-magnetic adjusting ring, 36-outer layer air gap, 37-outer layer air gap groove, 38-outer rotor, 39-outer rotor permanent magnet. DETAILED DESCRIPTION

[0030] The technical scheme of the utility model will be further described in detail in combination with the drawings:

[0031] For example, Figure 1As shown, the utility model discloses a magnetic gear optical type incremental encoder includes motor casing 12, mechanical rotating shaft 1, optical type incremental encoder and coaxial magnetic gear 3. Mechanical rotating shaft 1 passes through motor casing 12, and the direction of mechanical rotating shaft 1 is clockwise rotation. The mechanical rotating shaft 1 is distributed with bearing 2 and coaxial magnetic gear 3. Bearing 2 and coaxial magnetic gear 3 follow mechanical rotating shaft 1 and rotate clockwise. The coaxial magnetic gear 3 is in the inside of photoelectric code disc 5 in optical type incremental encoder. Optical type incremental encoder mainly by photoelectric code disc 5, emitting diode 6, convex lens 7, light barrier plate 8, photosensitive tube 9, Amp amplifier 10. The photoelectric code disc 5 is mainly made of optical glass, and there are multiple uniform size uniform distribution light transmission grooves 4 on its edge, the photoelectric code disc 5 except the part of uniform distribution light transmission grooves 4, the surface of its remaining part is plated with a layer of opaque metal chromium. The photoelectric code disc 5 has a sheath 11 outside, and the sheath 11 is made of aluminum alloy. A phase, B phase, Z phase are distributed on different positions of the uniformly distributed light transmission grooves 4 in the photoelectric code disc 5. Among them, A phase and B phase are two main output signals of optical type incremental encoder, and the phase difference is 90 degrees, and the effect of A phase and B phase is to judge the rotating direction and speed of optical type incremental encoder. The function of Z phase is different from A phase and B phase, and Z phase is the zero output signal of optical type encoder, which is used as a reference point of optical type incremental encoder, so as to determine the position of optical type incremental encoder. The emitting diode 6 is an infrared LED lamp with self condensing effect, which mainly emits light (optical signal) to the concave lens 7 as far as possible, so that the light (optical signal) passes through the convex lens 7. The convex lens 7 is directly behind the emitting diode 6, which is mainly made of glass material, and the convex lens 7 also plays a role in converging light, and can pass the converging light (optical signal) through the uniformly distributed light transmission grooves 4 on the photoelectric code disc 5, and the uniformly distributed light transmission grooves 4 are square light transmission grooves. The light barrier plate 8 directly behind the photoelectric code disc 5 is a circular shielding piece made of metal, and the light barrier plate 8 has a plurality of square slits, and the light, i.e. optical signal, passes through the plurality of square centripetal light transmission slits on the photoelectric code disc 5, and then passes through the plurality of square slits on the light barrier plate 8. The photosensitive tube 9 directly behind the light barrier plate 8 is a photosensitive element, and the photosensitive tube 9 is mainly made of semiconductor material, and the photosensitive tube 9 converts the optical signal transmitted by the light barrier plate 8 into an electric pulse signal, and then transmits the electric pulse signal to the Amp amplifier 10. The Amp amplifier 10 is directly behind the photosensitive tube 9, which is mainly made of semiconductor material and electronic element, and the Amp amplifier 10 can amplify the electric pulse signal, so as to effectively output the electric pulse signal, and finally complete the data transmission. Among them, the emitting diode 6, the convex lens 7, the light barrier plate 8, the photosensitive tube 9 and the Amp amplifier 10 are all directly above the mechanical rotating shaft 1, and one-to-one correspondence.

[0032] The coaxial magnetic gear 3 designed in this utility model is as follows: Figure 2 As shown, the coaxial magnetic gear 3 is penetrated by the mechanical bearing 1 and fixed on the mechanical shaft 1, embedded inside the photoelectric encoder disk 5. The coaxial magnetic gear 3 consists of an outer rotor 38, an inner rotor 31, and a magnetic adjustment ring 35. The inner ring of the outer rotor 38 has annular permanent magnets distributed on it, referred to as the outer rotor permanent magnet 39. The magnetization directions of adjacent permanent magnets on the outer rotor permanent magnet 39 are opposite. The outer rotor permanent magnet 39 is mainly made of neodymium iron boron permanent magnet material. The outer ring of the inner rotor 31 has annular permanent magnets distributed on it, referred to as the inner rotor permanent magnet 32. The magnetization directions of adjacent permanent magnets on the inner rotor permanent magnet 32 ​​are opposite. The inner rotor permanent magnet 32 ​​is mainly made of neodymium iron boron permanent magnet material. A layer of metal glue is coated on the surface of both the outer rotor permanent magnet 39 and the inner rotor permanent magnet 32, forming a protective film on the surface of the permanent magnets, thereby protecting the permanent magnets and reducing motor noise and vibration during rotation. The outer rotor 38 has numerous uniformly arranged slots 30 of the same size on its outer ring. These slots are arranged in two rows around the central axis, with both rows maintaining the same size. The square slots 30 facilitate airflow and enhance heat dissipation. The light emitted by the LED 6, after being focused by a convex lens, continues to propagate not only through the multiple square slits on the photoelectric encoder disk but also through the two rows of slots 30 on the outer rotor 38. This increased number of slots on the outer rotor 38 improves the output efficiency of the optical signal and enhances the signal quality. The tuning ring 35 employs a double-bridge structure, consisting of multiple tuning core blocks connected in series, and is placed between the inner and outer rotors. The air gaps between the outer rotor 38, the inner rotor 31, and the tuning ring 35 are referred to as the outer air gap 36 and the inner air gap 33, respectively. The inner air gap grooves 34 are located at the upper part of the connection between the tuning magnet core blocks, and the outer air gap grooves 37 are located at the lower part of the connection between the tuning magnet core blocks. The inner air gap grooves 34 and the outer air gap grooves 37 are of different sizes, with the outer air gap groove 37 being twice the size of the inner air gap grooves 34. The number of pole pairs of the outer rotor permanent magnet, the number of pole pairs of the inner rotor permanent magnet, and the number of tuning magnet core blocks satisfy the following formula: Number of pole pairs of the inner rotor permanent magnet + Number of pole pairs of the outer rotor permanent magnet = Number of tuning magnet core blocks.

[0033] The coaxial magnetic gear 3 can accelerate the rotation of the entire mechanical rotating shaft 1 and the photoelectric encoder 5 during rotation. Light (optical signal) is emitted from the light-emitting diode 6, and then the emitted light (optical signal) is emitted through the convex lens 7. The convex lens 7 converges the light (optical signal), and then the converged light passes through the rotating photoelectric encoder 5 and the outer rotor slot hole 30 on the edge of the rotating outer rotor 38. The light (optical signal) is emitted through the above two paths, thereby forming an intermittent light signal. In addition, during rotation, the surrounding airflow passes through the outer rotor slot hole 30 on the outer rotor 38, thereby accelerating the flow speed of the surrounding airflow and improving the air circulation. The optical signal passes through the photoelectric encoder 5 and the outer rotor slot hole 30 on the outer rotor 38, and then passes through the plurality of square slits on the fixed light barrier plate 8. The optical signal mainly includes A-phase, B-phase and Z-phase signals. During motor operation, some flowing gas also passes through the outer rotor slot hole 30, which enhances the air circulation and promotes the air circulation, thereby achieving a certain degree of heat dissipation effect. The intermittent light signal then passes through the photosensitive tube 9 and is converted into a periodic electric pulse signal. Then the electric pulse signal is amplified by the Amp amplifier 10, and finally the electric pulse signal is output. During the rotation of the entire coaxial magnetic gear 3, the magnetic adjusting ring 35 with a double-bridge structure on the coaxial magnetic gear 3 improves the operation efficiency of the inner rotor 31 and the outer rotor 38 due to the unique groove structure, reduces the interference of the coaxial magnetic gear 3 on the optical incremental encoder, thereby driving the speed of the photoelectric encoder, and improving the operation efficiency of the entire optical incremental encoder. During operation, the coaxial magnetic gear has no friction and small energy loss, so that the signal output by the optical encoder is more stable and the data is more accurate. In addition, the inner rotor permanent magnet 32 and the outer rotor permanent magnet 39 on the coaxial magnetic gear 3 are coated with a layer of metal glue, which protects the inner rotor permanent magnet 32 and the outer rotor permanent magnet 39, reduces the noise and vibration of the motor, and makes the structure of the entire inner rotor permanent magnet 32 and the outer rotor permanent magnet 39 more stable, thereby improving the operation efficiency of the optical incremental encoder.

[0034] The coaxial magnetic gear optical incremental encoder is suitable for industrial production, precision machining, intelligent manufacturing, automation equipment, medical equipment, scientific research experiments, automobiles, ships, aircraft and other mobile devices. It is widely used in industrial production scenes that need to monitor or control mechanical systems, including industrial control, robots, camera lenses, radar platforms and some computer input devices, such as trackballs and mouse rollers. It is especially suitable for special occasions with high reliability requirements, non-contact, non-friction and stable operation in harsh environments.

[0035] The above merely describes a specific implementation of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A coaxial magnetic gear optical incremental encoder, comprising a motor housing, and a mechanical rotating shaft in the motor housing, bearings and an optical encoder disc are distributed on the mechanical rotating shaft, characterized in that, The photoelectric encoder comprises a coaxial magnetic gear, which comprises, from inside to outside, an inner rotor, a magnetic adjusting ring and an outer rotor. The inner rotor is fixed on a mechanical rotating shaft, and the outer circle of the inner rotor is provided with inner rotor permanent magnets, the magnetization directions of adjacent two inner rotor permanent magnets are opposite, the inner circle of the outer rotor is provided with outer rotor permanent magnets, the magnetization directions of adjacent two outer rotor permanent magnets are opposite, the number of pole pairs of the inner rotor permanent magnets is not equal to the number of pole pairs of the outer rotor permanent magnets, and the magnetic adjusting ring has a gap with the inner rotor and the outer rotor. The outer circle of the outer rotor is uniformly provided with a plurality of square slot holes.

2. A coaxial magnetic gear optical incremental encoder according to claim 1, characterized in that, The magnetic adjusting ring is a double-bridge type magnetic adjusting ring, which comprises a plurality of magnetic adjusting core blocks connected in series, the connection part between the magnetic adjusting core blocks comprises an upper groove and a lower groove, the upper groove is close to the outer rotor permanent magnet, the lower groove is close to the inner rotor permanent magnet, the upper groove and the lower groove are not equal in size, and the number of the magnetic adjusting core blocks is related to the number of pole pairs of the inner rotor permanent magnets and the number of pole pairs of the outer rotor permanent magnets, i.e. the number of the magnetic adjusting core blocks = the number of pole pairs of the inner rotor permanent magnets + the number of pole pairs of the outer rotor permanent magnets.

3. A coaxial magnetic gear optical incremental encoder according to claim 2, characterized in that, The size of the upper groove is twice that of the lower groove.

4. A coaxial magnetic gear optical incremental encoder according to claim 2, characterized in that, There is an air gap between the upper groove of the magnetic adjusting ring and the outer rotor permanent magnet, which is referred to as an outer air gap, and there is an air gap between the lower groove of the magnetic adjusting ring and the inner rotor permanent magnet, which is referred to as an inner air gap.

5. A coaxial magnetic gear optical incremental encoder according to claim 1, characterized in that, The square slot holes are consistent in size.

6. A coaxial magnetic gear optical incremental encoder according to claim 1, characterized in that, The inner rotor permanent magnet and the outer rotor permanent magnet are annular permanent magnets.

7. A coaxial magnetic gear optical incremental encoder according to claim 1, characterized in that, The surfaces of the outer rotor permanent magnet and the inner rotor permanent magnet are coated with metal glue.

8. A coaxial magnetic gear optical incremental encoder according to claim 1, characterized in that, The photoelectric encoder is provided with a plurality of square centripetal light transmission slits consistent in size on the edge, the centripetal light transmission slits are equidistant and equal in width on the circumference of the photoelectric encoder, and the rest of the photoelectric encoder is not light-transmitting.

9. A coaxial magnetic gear optical incremental encoder according to claim 8, characterized in that, The surface of the rest of the photoelectric encoder is plated with metal chromium.

10. A coaxial magnetic gear optical incremental encoder according to claim 1, characterized in that, The photoelectric encoder further comprises a light-emitting diode, a convex lens, a light barrier plate, a photosensitive tube and an Amp amplifier, wherein the convex lens is arranged in front of the photoelectric encoder, the light-emitting diode is arranged in front of the convex lens, the light barrier plate is arranged behind the photoelectric encoder, the light barrier plate is provided with a plurality of square slits, the photosensitive tube is arranged behind the light barrier plate, the photosensitive tube is used for converting a light signal into an electric pulse signal, the photosensitive tube is connected with the Amp amplifier behind the photoelectric encoder, and the Amp amplifier is used for amplifying the electric pulse signal and then outputting the amplified electric pulse signal.

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