A multi-turn absolute value encoder

Abstract

The application belongs to the technical field of encoders, and particularly relates to a multi-turn absolute value encoder, which comprises a shell, a gear set, a main shaft, a multi-turn circuit board, a code disc and a buffer unit. When a motor is shocked and vibrates during operation, the main shaft is first impacted and vibrates due to force transmission, and then transmits the force to the buffer unit. The buffer unit disperses and conducts the impact force received by the main shaft and the rotating shaft, thereby weakening the vibration of the code disc, reducing light source jumping, improving detection accuracy, dispersing the force received by the main shaft through the buffer unit, and prolonging the service life of the main shaft.

Description

Technical Field

[0001] This invention belongs to the field of encoder technology, specifically a multi-turn absolute encoder. Background Technology

[0002] An encoder is a device that measures the position or rotational speed of a motor shaft. It is usually made based on optical and magnetoelectric principles. Encoders are classified into incremental and absolute types according to the engraving method of the code disk. Absolute encoders record the absolute position of the rotor and read the current position information of the motor shaft. The absolute position can be identified by the amplitude of the output signal or the physical encoding scale of the grating. A multi-turn absolute encoder is one that, within its measurement range, not only has "absolute encoding" within a single 360-degree turn, but also has a unique absolute encoding for multiple turns of value that does not depend on counting after exceeding 360 degrees.

[0003] Currently, most multi-turn absolute encoders are optical multi-turn absolute encoders, which use mechanical gear sets to record the number of turns. Because they use optical detection methods with grating code disks, they have high requirements for the detection environment. If the motor vibrates during operation, it will cause the light inside the encoder to jump, affecting the detection accuracy. In addition, the spindle in the mechanical gear set is the first to be stressed and the stress is greater when the motor vibrates, which reduces the service life of the spindle.

[0004] In view of this, in order to improve the above-mentioned technical problems, the present invention provides a multi-turn absolute encoder, which improves the above-mentioned technical problems. Summary of the Invention

[0005] The technical problem to be solved by this invention is as follows: Currently, most multi-turn absolute encoders are optical multi-turn absolute encoders, which use mechanical gear sets to record the number of turns. Because they use optical detection methods with grating code disks, they have high requirements for the detection environment. If the motor vibrates during operation, it will cause the light inside the encoder to jump, affecting the detection accuracy. Moreover, in the mechanical gear set, the spindle is the first to be stressed and the stress is greater when the motor vibrates, which reduces the service life of the spindle.

[0006] The present invention provides a multi-turn absolute encoder, wherein the multi-turn absolute sensor includes: a housing, a gear set, a main shaft, a multi-turn circuit board, a code disk, and a buffer unit;

[0007] The gear set is located inside the housing. The gear set includes a main drive gear and multiple driven gears. The main drive gear is located at the center of the housing, and the multiple driven gears are located around the main drive gear. All of the multiple driven gears mesh with the main drive gear, and a rotating shaft is fixedly installed at the center of each of the multiple driven gears.

[0008] The main shaft passes through the center of the main drive gear, and the main shaft is fixedly connected to the main drive gear;

[0009] The multi-turn circuit board is located below the gear set, and the gear set is mounted on the multi-turn circuit board via a rotating shaft;

[0010] The driven gear and the driving gear are equipped with code disks, and the code disks are equipped with light sources;

[0011] The buffer unit is located between the gear set and the multi-turn circuit board. The buffer unit is used to reduce the vibration of the gear set and the spindle and to disperse the impact force on the spindle.

[0012] When the motor is working, the multi-turn absolute encoder operates, and the main shaft rotates, driving the main drive gear to rotate. When the main drive gear rotates, it drives multiple driven gears to rotate through gear meshing. When the motor vibrates due to impact during operation, the main shaft is the first to be impacted and vibrates due to force transmission. After the main shaft is impacted, it transmits the force to the buffer unit. The buffer unit disperses and transmits the impact on the main shaft and the rotating shaft, thereby weakening the vibration of the code disk, reducing light source jump, and improving detection accuracy. At the same time, the buffer unit can disperse the force on the main shaft and improve the service life of the main shaft.

[0013] Compared to existing technologies, where the motor vibrates during operation and this vibration is transmitted to the encoder, causing the encoder's internal light source to flicker and reducing detection accuracy, this invention incorporates a buffer unit. When the motor vibrates due to impact during operation, the spindle is the first to be impacted and vibrates due to force transmission. The spindle then transmits the force to the buffer unit, which disperses and transmits the impact on the spindle and shaft, thereby weakening the code disk's vibration, reducing light source flicker, and improving detection accuracy. Simultaneously, the buffer unit disperses the force on the spindle, extending its service life.

[0014] Preferably, the buffer unit includes: a load-bearing plate and a conductive component;

[0015] The load-bearing plate is located below the gear set. The main shaft passes through the load-bearing plate and is slidably connected to the load-bearing plate via a spline. The shafts of the multiple driven gears all pass through the load-bearing plate and are slidably connected to the load-bearing plate via splines.

[0016] A conductive component, wherein multiple conductive components are provided, and the multiple conductive components are evenly arranged in a circumferential shape below the load-bearing plate;

[0017] The transmission component includes: a mounting bracket, a drive shaft, a push plate, a push block, a first spring, and a sliding block;

[0018] The mounting bracket is fixedly installed on one end face of the load-bearing plate near the multi-circuit circuit board.

[0019] The drive shaft is rotatably mounted on the mounting bracket;

[0020] The push plate is located near the edge of the load-bearing plate, and one end of the push plate is fixedly connected to the drive shaft.

[0021] The push block is located on the edge of the load-bearing plate. The push block is rotatably connected to the end of the push plate away from the drive shaft. The end face of the push block near the multi-turn circuit board is slidably connected to the multi-turn circuit board through a slider.

[0022] One end of the No. 1 spring is fixedly connected to the push block;

[0023] The sliding block is located at the edge of the multi-turn circuit board. The sliding block is slidably connected to the multi-turn circuit board via a slider. The end of the first spring away from the push block is fixedly connected to the fixed block.

[0024] When the motor is running, the multi-turn absolute encoder operates, causing the main shaft to rotate. The main shaft drives the main drive gear, which in turn drives multiple driven gears through gear meshing. When the motor vibrates due to impact during operation, the main shaft is the first to be affected by the impact force. This force is then transmitted to the load-bearing plate mounted on it. If the main shaft is not vibrating, the load-bearing plate follows the shaft and remains stationary under the support of the transmission components. When the main shaft vibrates, the load-bearing plate is impacted and vibrates. This vibration breaks its initial relative stillness, and under inertia, it moves up and down along the main shaft and rotating shaft. As the load-bearing plate moves upward, it transmits the force to the fixed mounting components. On the frame, the mounting bracket moves upward, pulling the push plate upward and rotating it. The upward rotation of the push plate pulls the push block towards the center of the housing. At this time, the first spring is in a stretched state, which offsets part of the impact force. When the load-bearing plate moves downward, it transmits the force to the mounting bracket fixed on it. The mounting bracket moves downward, pushing the push plate downward and rotating it downward, which pushes the push block towards the inner wall of the housing. At this time, the first spring is in a compressed state, which again offsets part of the impact force. At the same time, multiple transmission components work simultaneously, dispersing and transmitting the impact on the spindle and rotating shaft through the first spring, thereby weakening the vibration of the code disk, reducing light source jump, and improving detection accuracy. At the same time, the buffer unit can disperse the force on the spindle and improve the service life of the spindle.

[0025] Preferably, a plurality of transmission frames are circumferentially arranged on the outer surface of the housing. One end of each transmission frame is fixedly connected to the housing. A second spring is fixedly connected to the lower surface of the transmission frame. A mounting block is fixedly connected to the end of the second spring away from the transmission frame. A threaded hole is opened on the end face of the mounting block away from the second spring.

[0026] By setting a transmission frame on the housing and setting a second spring on the lower surface of the transmission frame, the encoder can be connected to the motor through the threaded hole on the mounting block when the encoder is installed. When the motor vibrates, the housing will also vibrate. When the housing vibrates, the elasticity of the second spring further alleviates the vibration of the entire device, including the housing, thereby further reducing the amplitude of light source fluctuation and improving detection accuracy.

[0027] Preferably, a sealing ring is fixed to the lower surface of the housing.

[0028] When the motor operates in a dusty or humid environment, dust or moisture in the air can easily enter the housing. As the main drive gear and driven gear rotate, the dust and moisture are disturbed by the rotating gears, increasing the complexity of molecular activity inside the housing, disturbing the light, and causing light refraction, which affects measurement accuracy. Therefore, by installing a sealing ring at the bottom of the housing, the sealing performance after installation can be effectively improved, reducing the entry of dust and moisture into the housing and improving detection accuracy.

[0029] Preferably, the end of the transmission frame away from the housing has a cross groove.

[0030] By providing a cross groove at the end of the transmission frame away from the housing, the encoder can be easily installed and positioned. This allows staff to calibrate the housing position using pins, preventing misalignment that could affect the encoder's sealing performance.

[0031] Preferably, a heat insulation layer is fixed to the outer surface of the housing.

[0032] When the motor operates in a high-temperature environment, the increased molecular activity in the air due to the high temperature affects the propagation of light from the light source. Therefore, by fixing a heat insulation layer to the outer surface of the housing, the influence of external high temperature on the internal temperature of the housing can be reduced, light fluctuations can be reduced, and detection accuracy can be further improved.

[0033] Preferably, the code disk is provided with an index coarse code and an incremental fine code. The coarse code is a code track composed of a series of non-uniform black and white stripes similar to a barcode, and the fine code is a code track composed of a series of uniformly interlaced black and white stripes.

[0034] A combination of coarse and fine codes is used to encode the position. The position is determined by setting an M-sequence pattern on the grating as the coarse code, and the output resolution is further improved by setting a uniformly distributed fine code on the grating. There is a special algorithm that can make the m-sequence pattern adaptable to gratings of any diameter by changing the parameters, increasing the flexibility of product design.

[0035] Preferably, the light source is powered by a photocell, and the light source and the photocell are located on the same side of the code disk.

[0036] By placing the light source and the photocell on the same side of the grating, the size is smaller than that of a transmissive grating encoder, and the thickness can be shortened by 2-5mm.

[0037] Preferably, the light source is a lensless LED, and the light source emitted by the lensless LED is blue light.

[0038] By using lensless LEDs as the light source, the difficulty and cost of sensor integration and packaging can be reduced. When using polymer materials for packaging, the ambient temperature resistance can be improved to a uniform temperature. Furthermore, by using lensless LEDs, the nominal gap and tolerance range of sensor installation can be increased to 1.7mm±0.4mm, which greatly reduces the difficulty of product setup and adjustment.

[0039] The technology of using blue LEDs as the light source solves the problem of poor original signal when using original infrared LEDs. The acquired signal quality is better, the noise is lower, and it is easier to achieve high-precision and high-resolution position output.

[0040] Preferably, the code disk is made of metal, which improves its impact resistance compared to traditional encoders that use glass substrates.

[0041] The beneficial effects of this invention are as follows:

[0042] 1. The present invention provides a multi-turn absolute encoder. By setting a buffer unit, when the motor vibrates due to impact during operation, the main shaft is the first to be impacted and vibrates due to force transmission. After the main shaft is impacted, it transmits the force to the buffer unit. The buffer unit disperses and transmits the impact on the main shaft and the rotating shaft, thereby weakening the vibration of the code disk, reducing light source fluctuation, and improving detection accuracy. At the same time, the buffer unit can disperse the force on the main shaft and improve the service life of the main shaft.

[0043] 2. The present invention provides a multi-turn absolute encoder, which has a transmission frame and a second spring in the housing. When the motor vibrates, the housing will also vibrate. When the housing vibrates, the elasticity of the second spring further alleviates the vibration of the whole device, including the housing, thereby further reducing the amplitude of light source fluctuation and improving detection accuracy.

[0044] 3. The multi-turn absolute encoder provided by the present invention can effectively improve the sealing performance of the housing after installation by setting a sealing ring at the bottom of the housing, reduce the entry of dust and moisture into the housing, and improve the detection accuracy.

[0045] 4. The multi-turn absolute encoder provided by the present invention has a cross groove at the end of the transmission frame away from the housing, which facilitates the installation and positioning of the encoder and avoids misalignment that would affect the sealing performance of the encoder.

[0046] 5. The multi-turn absolute encoder provided by the present invention can reduce the influence of external high temperature on the internal temperature of the housing by fixing a heat insulation layer on the outer surface of the housing, reduce light fluctuation, and further improve detection accuracy.

[0047] 6. The present invention provides a multi-turn absolute encoder with index coarse code and incremental fine code on the code disk. The position is encoded by a combination of coarse code and fine code. The position is determined by setting an M-sequence pattern on the grating as coarse code, and the output resolution is further improved by setting uniformly distributed fine code on the grating. A special algorithm can be used to change the parameters so that the m-sequence pattern can be adapted to the grating of any diameter, increasing the flexibility of product design.

[0048] 7. The present invention provides a multi-turn absolute encoder, which, by placing the light source and the photocell on the same side of the grating, is smaller in size than a transmissive grating encoder and can be 2-5mm shorter in thickness.

[0049] 8. The multi-turn absolute encoder provided by the present invention can reduce the difficulty and cost of sensor integration and packaging by using lensless LED as the light source. When using polymer materials for packaging, the ambient temperature resistance can be improved to uniform temperature. Furthermore, by using lensless LED, the nominal gap and tolerance range of sensor installation can be increased to 1.7mm±0.4mm, which greatly reduces the difficulty of product adjustment in application.

[0050] The technology of using blue LEDs as the light source solves the problem of poor original signal when using original infrared LEDs. The acquired signal quality is better, the noise is lower, and it is easier to achieve high-precision and high-resolution position output.

[0051] 9. The present invention provides a multi-turn absolute encoder with a code disk made of metal material, which improves the impact resistance compared with traditional encoders using glass substrate. Attached Figure Description

[0052] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0053] Figure 1 This is a schematic diagram of a partial cross-sectional view of the present invention.

[0054] Figure 2 This is a schematic diagram of the overall appearance and structure of the present invention;

[0055] Figure 3 This is a bottom-view structural diagram of the present invention;

[0056] Figure 4 This is a schematic diagram of the gear assembly structure of the present invention;

[0057] Figure 5 This is a schematic diagram of the structure of the conductive element in this invention;

[0058] Figure 6 For the present invention Figure 5 Enlarged view of point A in the middle;

[0059] Figure 7 This is a schematic diagram illustrating the reflection principle at the light source and photovoltaic cell of the present invention.

[0060] Figure 8 This is a schematic diagram of the coarse and fine codes of the present invention;

[0061] In the diagram: 1. Housing; 2. Gear set; 21. Main drive gear; 22. Driven gear; 3. Main shaft; 4. Multi-turn circuit board; 5. Encoder disk; 6. Buffer unit; 61. Load-bearing plate; 62. Conductor; 62. Mounting bracket; 621. Drive shaft; 622. Push plate; 623. Push block; 624. Spring No. 1; 625. Sliding block; 626. Conductor frame; 7. Spring No. 2; 8. Cross groove; 9. Mounting block; 10. Detailed Implementation

[0062] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0063] like Figure 1 As shown, the present invention provides a multi-turn absolute encoder, the multi-turn absolute sensor comprising: a housing 1, a gear set 2, a main shaft 3, a multi-turn circuit board 4, a code disk 5, and a buffer unit 6;

[0064] The gear set 2 is located inside the housing 1. The gear set 2 includes a main drive gear 21 and multiple driven gears 22. The main drive gear 21 is located at the center of the housing 1, and the multiple driven gears 22 are located around the main drive gear 21. The multiple driven gears 22 mesh with the main drive gear 21, and a rotating shaft is fixedly installed at the center of each of the multiple driven gears 22.

[0065] The main shaft 3 passes through the center of the main drive gear 21, and the main shaft 3 is fixedly connected to the main drive gear 21;

[0066] The multi-turn circuit board 4 is located below the gear set 2, and the gear set 2 is mounted on the multi-turn circuit board 4 via a rotating shaft;

[0067] The driven gear 22 and the driving gear are equipped with an encoder 5, and the encoder 5 is equipped with a light source.

[0068] The buffer unit 6 is located between the gear set 2 and the multi-turn circuit board 4. The buffer unit 6 is used to reduce the vibration between the gear set 2 and the main shaft 3 and to disperse the impact force on the main shaft 3.

[0069] By adopting the above technical solution, when the motor is working, the multi-turn absolute encoder is working. At this time, the main shaft 3 rotates, and the main shaft 3 drives the main drive gear 21 to rotate. When the main drive gear 21 rotates, it drives multiple driven gears 22 to rotate through gear meshing. When the motor vibrates due to impact during operation, the main shaft 3 is the first to be impacted and vibrates due to force transmission. After the main shaft 3 is impacted, it transmits the force to the buffer unit 6. The buffer unit 6 disperses and transmits the impact on the main shaft 3 and the rotating shaft, thereby weakening the vibration of the code disk 5, reducing light source jump, and improving detection accuracy. At the same time, the buffer unit 6 can disperse the force on the main shaft 3 and improve the service life of the main shaft 3.

[0070] Compared to existing technologies, where the motor vibrates during operation and this vibration is transmitted to the encoder, causing the encoder's internal light source to flicker and reducing detection accuracy, this invention incorporates a buffer unit 6. When the motor vibrates due to impact during operation, the main shaft 3 is the first to be impacted and vibrates due to force transmission. The main shaft 3 then transmits the impact force to the buffer unit 6, which disperses and transmits the impact on the main shaft 3 and the rotating shaft, thereby weakening the vibration of the code disk 5, reducing light source flicker, and improving detection accuracy. At the same time, the buffer unit 6 disperses the force on the main shaft 3, extending its service life.

[0071] like Figure 1 , Figure 4 , Figure 5 and Figure 6 As shown, in a specific embodiment of the present invention, the buffer unit 6 includes: a load-bearing plate 61 and a conductive member 62;

[0072] The load-bearing plate 61 is located below the gear set 2. The main shaft 3 passes through the load-bearing plate 61 and is slidably connected to the load-bearing plate 61 via a spline. The rotating shafts of the multiple driven gears 22 all pass through the load-bearing plate and are slidably connected to the load-bearing plate 61 via a spline.

[0073] A plurality of conductive elements 62 are provided, and the plurality of conductive elements 62 are evenly arranged in a circumferential shape below the load-bearing plate 61;

[0074] The transmission component 62 includes: a mounting bracket 621, a drive shaft 622, a push plate 623, a push block 624, a first spring 625, and a sliding block 626;

[0075] The mounting bracket 621 is fixedly installed on one end face of the load-bearing plate 61 near the multi-turn circuit board 4;

[0076] The drive shaft 622 is rotatably mounted on the mounting bracket 621;

[0077] The push plate 623 is located near the edge of the bearing plate 61, and one end of the push plate 623 is fixedly connected to the drive shaft 622.

[0078] The push block 624 is located on the edge of the load-bearing plate 61. The push block 624 is rotatably connected to the end of the push plate 623 away from the drive shaft 622. The end face of the push block 624 near the multi-turn circuit board 4 is slidably connected to the multi-turn circuit board 4 through a slider.

[0079] One end of the first spring 625 is fixedly connected to the push block 624;

[0080] The sliding block 626 is located at the edge of the multi-turn circuit board 4. The sliding block 626 is slidably connected to the multi-turn circuit board 4 through a slider. The end of the first spring 625 away from the push block 624 is fixedly connected to the fixed block.

[0081] By adopting the above technical solution, when the motor is working, the multi-turn absolute encoder operates, and the main shaft 3 rotates. The main shaft 3 drives the main drive gear 21 to rotate. When the main drive gear 21 rotates, it drives multiple driven gears 22 to rotate through gear meshing. When the motor vibrates due to impact during operation, the main shaft 3 is the first to be impacted and vibrates due to force transmission. After the main shaft 3 is impacted, it transmits the force to the load-bearing plate 61 mounted on it. If the main shaft 3 does not vibrate, the load-bearing plate 61 follows the main shaft 3 and remains stationary under the support of the transmission component 62. When the main shaft 3 vibrates, the load-bearing plate 61 is impacted and vibrates. When the load-bearing plate 61 vibrates, it breaks its original relatively static state and moves up and down along the main shaft 3 and the rotating shaft under the action of inertia. When the load-bearing plate 61 moves upward, it transmits the force to the mounting bracket 621 fixedly mounted on it. When 621 moves upward, it pulls the push plate 623 to rotate upward. The upward rotation of the push plate 623 pulls the push block 624 to move towards the center of the housing 1. At this time, the first spring 625 is in a stretched state. The first spring 625 in a stretched state offsets part of the impact force. When the load-bearing plate 61 moves downward, it transmits the force to the mounting bracket 621 fixed on it. The mounting bracket 621 moves downward and pushes the push plate 623 to rotate downward. The downward rotation of the push plate 623 pushes the push block 624 to move towards the inner wall of the housing 1. At this time, the first spring 625 is in a compressed state. The first spring 625 in a compressed state offsets part of the impact force again. At the same time, multiple transmission components 62 work simultaneously to disperse and transmit the impact on the main shaft 3 and the rotating shaft through the first spring 625, thereby weakening the vibration of the code disk 5, reducing the light source jump, and improving the detection accuracy. At the same time, through the buffer unit 6, the force on the main shaft 3 can be dispersed, and the service life of the main shaft 3 can be improved.

[0082] like Figure 2 and Figure 3 As shown, in a specific embodiment of the present invention, a plurality of transmission frames 7 are circumferentially arranged on the outer surface of the housing 1. One end of the transmission frame 7 is fixedly connected to the housing 1. A second spring 8 is fixedly connected to the lower surface of the transmission frame 7. A mounting block 10 is fixedly connected to the end of the second spring 8 away from the transmission frame 7. A threaded hole is opened on the end face of the mounting block 10 away from the second spring 8.

[0083] By adopting the above technical solution, a transmission frame 7 is provided at the housing 1, and a second spring 8 is provided on the lower surface of the transmission frame 7. When the encoder is installed, the encoder can be connected to the motor through the threaded hole on the mounting block 10. When the motor vibrates, the housing 1 will also vibrate. When the housing 1 vibrates, the elasticity of the second spring 8 further alleviates the vibration of the entire device, including the housing 1, thereby further reducing the amplitude of the light source fluctuation and improving the detection accuracy.

[0084] In one specific embodiment of the present invention, a sealing ring is fixedly connected to the lower surface of the housing 1;

[0085] By adopting the above technical solution, when the motor is working in a high-dust or high-humidity working environment, dust or water vapor in the air can easily enter the interior of the housing 1. As the main drive gear 21 and driven gear 22 rotate, the dust and water vapor are disturbed by the rotating main drive gear 21 and driven gear 22, which increases the complexity of molecular activity inside the housing 1, disturbs the light, and easily causes light refraction and other phenomena, affecting the measurement accuracy. Therefore, by setting a sealing ring at the bottom of the housing 1, the sealing performance of the housing 1 after installation can be effectively improved, reducing the entry of dust and water vapor into the interior of the housing 1 and improving the detection accuracy.

[0086] like Figure 2 As shown, in a specific embodiment of the present invention, the conduction frame 7 has a cross groove 9 at the end away from the housing 1;

[0087] By adopting the above technical solution, a cross groove 9 is provided at the end of the transmission frame 7 away from the housing 1, which facilitates the installation and positioning of the encoder and allows the staff to calibrate the position of the housing 1 by means of a pin, thus avoiding misalignment that could affect the sealing performance of the encoder.

[0088] In one specific embodiment of the present invention, a heat insulation layer is fixedly attached to the outer surface of the housing 1.

[0089] By adopting the above technical solution, when the motor is working in a high-temperature environment, the high temperature will increase the movement of molecules in the air, thereby affecting the light propagation of the light source. Therefore, by fixing a heat insulation layer on the outer surface of the housing 1, the influence of the external high temperature on the internal temperature of the housing 1 can be reduced, the light fluctuation can be reduced, and the detection accuracy can be further improved.

[0090] like Figure 8 As shown, in a specific embodiment of the present invention, the code disk 5 is provided with an index coarse code and an incremental fine code. The coarse code is a code track composed of a series of non-uniform black and white stripes similar to a barcode, and the fine code is a code track composed of a series of uniformly interlaced black and white stripes.

[0091] By adopting the above technical solution, a combination of coarse and fine codes is used to encode the position. The position is determined by setting an M-sequence pattern on the grating as the coarse code, and the output resolution is further improved by setting a uniformly distributed fine code on the grating. There is a special algorithm that can make the m-sequence pattern adapt to gratings of any diameter by changing the parameters, thereby increasing the flexibility of product design.

[0092] like Figure 7 As shown, in a specific embodiment of the present invention, the light source is powered by a photocell, and the light source and the photocell are located on the same side of the code disk 5.

[0093] By adopting the above technical solution, and by placing the light source and the photocell on the same side of the grating, the size is smaller than that of the transmissive grating encoder, and the thickness can be shortened by 2-5mm.

[0094] In one specific embodiment of the present invention, the light source is a lensless LED, and the light source emitted by the lensless LED is blue light;

[0095] By adopting the above technical solution and using lensless LEDs as the light source, the difficulty and cost of sensor integration and packaging can be reduced. When using polymer materials for packaging, the ambient temperature resistance can be improved to a uniform temperature. Furthermore, by using lensless LEDs, the nominal gap and tolerance range of sensor installation can be increased to 1.7mm±0.4mm, which greatly reduces the difficulty of product adjustment in application.

[0096] The technology of using blue LEDs as the light source solves the problem of poor original signal when using original infrared LEDs. The acquired signal quality is better, the noise is lower, and it is easier to achieve high-precision and high-resolution position output.

[0097] In one specific embodiment of the present invention, the code disk 5 is made of metal material;

[0098] By adopting the above technical solution, the impact resistance is improved compared with the traditional encoder that uses glass substrate.

[0099] Working principle:

[0100] When the motor is working, the multi-turn absolute encoder operates, causing the main shaft 3 to rotate. The main shaft 3 drives the main drive gear 21 to rotate, which in turn drives multiple driven gears 22 through gear meshing. When the motor vibrates due to impact during operation, the main shaft 3 is the first to be impacted and vibrates due to force transmission. The main shaft 3 then transmits the force to the load-bearing plate 61 mounted on it. If the main shaft 3 does not vibrate, the load-bearing plate 61 follows the main shaft 3 and remains stationary under the support of the transmission component 62. When the main shaft 3 vibrates, the load-bearing plate 61 is impacted and vibrates. This vibration breaks its original relative static state, and under the action of inertia, it moves up and down along the main shaft 3 and the rotating shaft. When the load-bearing plate 61 moves upward, it transmits the force to the mounting bracket 621 fixed on it. The upward movement of the mounting bracket 621 pulls... The push plate 623 rotates upward, pulling the push block 624 towards the center of the housing 1. At this time, the first spring 625 is in a stretched state, which offsets part of the impact force. When the load-bearing plate 61 moves downward, it transmits the force to the mounting bracket 621 fixed on it. The mounting bracket 621 moves downward, pushing the push plate 623 to rotate downward. The push plate 623 rotates downward, pushing the push block 624 towards the inner wall of the housing 1. At this time, the first spring 625 is in a compressed state, which again offsets part of the impact force. At the same time, multiple transmission components 62 work simultaneously, dispersing and transmitting the impact on the main shaft 3 and the rotating shaft through the first spring 625, thereby weakening the vibration of the code disk 5, reducing light source jump, and improving detection accuracy. At the same time, the buffer unit 6 can disperse the force on the main shaft 3 and improve the service life of the main shaft 3.

[0101] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A multi-turn absolute encoder, characterized in that: The multi-turn absolute encoder includes: a housing (1), a gear set (2), a main shaft (3), a multi-turn circuit board (4), a code disk (5), and a buffer unit (6); The gear set (2) is located inside the housing (1). The gear set (2) includes a main drive gear (21) and multiple driven gears (22). The main drive gear (21) is located at the center of the housing (1), and the multiple driven gears (22) are located around the main drive gear (21). The multiple driven gears (22) mesh with the main drive gear (21), and a rotating shaft is fixedly installed at the center of each of the multiple driven gears (22). The main shaft (3) passes through the center of the main drive gear (21), and the main shaft (3) is fixedly connected to the main drive gear (21); The multi-turn circuit board (4) is located below the gear set (2), and the gear set (2) is mounted on the multi-turn circuit board (4) via a rotating shaft; The driven gear (22) and the main drive gear (21) are equipped with code disks (5), and the code disks (5) are equipped with light sources; The buffer unit (6) is located between the gear set (2) and the multi-turn circuit board (4). The buffer unit (6) is used to alleviate the vibration between the gear set (2) and the main shaft (3) and to disperse the impact force on the main shaft (3). The buffer unit (6) includes: a load-bearing plate (61) and a conductive component (62); The load-bearing plate (61) is located below the gear set (2). The main shaft (3) passes through the load-bearing plate (61) and is slidably connected to the load-bearing plate (61) via a spline. The shafts of the multiple driven gears (22) all pass through the load-bearing plate (61) and are slidably connected to the load-bearing plate (61) via a spline. A plurality of conductive elements (62) are provided, and the plurality of conductive elements (62) are evenly arranged in a circumferential shape below the load-bearing plate (61); The transmission component (62) includes: a mounting bracket (621), a drive shaft (622), a push plate (623), a push block (624), a first spring (625), and a sliding block (626); The mounting bracket (621) is fixedly installed on one end face of the load-bearing plate (61) near the multi-circuit circuit board (4); The drive shaft (622) is rotatably mounted on the mounting bracket (621); The push plate (623) is located near the edge of the load-bearing plate (61), and one end of the push plate (623) is fixedly connected to the drive shaft (622). The push block (624) is located on the edge of the load-bearing plate (61). The push block (624) is rotatably connected to the end of the push plate (623) away from the drive shaft (622). The end face of the push block (624) close to the multi-turn circuit board (4) is slidably connected to the multi-turn circuit board (4) through a slider. One end of the first spring (625) is fixedly connected to the push block (624); The sliding block (626) is located at the edge of the multi-turn circuit board (4). The sliding block (626) is slidably connected to the multi-turn circuit board (4) through a slider. The end of the first spring (625) away from the push block (624) is fixedly connected to the sliding block (626). Multiple transmission frames (7) are circumferentially arranged on the outer surface of the housing (1). One end of the transmission frame (7) is fixed to the housing (1). A second spring (8) is fixed to the lower surface of the transmission frame (7). A mounting block (10) is fixed to the end of the second spring (8) away from the transmission frame (7). A threaded hole is opened on the end face of the mounting block (10) away from the second spring (8).

2. The multi-turn absolute encoder according to claim 1, characterized in that: A sealing ring is fixed to the lower surface of the housing (1).

3. A multi-turn absolute encoder according to claim 1, characterized in that: The transmission frame (7) has a cross groove (9) at the end away from the shell (1).

4. A multi-turn absolute encoder according to claim 1, characterized in that: A heat insulation layer is fixed to the outer surface of the shell (1).

5. A multi-turn absolute encoder according to claim 1, characterized in that: The code disk (5) is provided with an index coarse code and an incremental fine code. The coarse code is a code track composed of a series of non-uniform black and white stripes similar to a barcode, and the fine code is a code track composed of a series of uniformly interlaced black and white stripes.

6. A multi-turn absolute encoder according to claim 1, characterized in that: The light source is powered by a photocell, and the light source and the photocell are located on the same side of the code disk (5).

7. A multi-turn absolute encoder according to claim 6, characterized in that: The light source is a lensless LED, and the light emitted by the lensless LED is blue light.

8. A multi-turn absolute encoder according to claim 1, characterized in that: The code disk (5) is made of metal.

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