High-precision circular grating encoder

Abstract

The utility model provides a high-precision circular grating encoder, which comprises a fixed seat, a rotating shaft assembly, a circuit board assembly, a chip assembly, a movable grating and an upper cover assembly, the rotating shaft assembly is rotatably mounted in the middle of the fixed seat, the circuit board assembly is fixed above the fixed seat, and the chip assembly is fixed above the fixed seat. The chip assembly is fixed above the circuit board assembly and is electrically connected with the circuit board assembly, the movable grating is fixed at the power output end of the rotating shaft assembly and corresponds to the upper part of the chip assembly, the lower end of the upper cover assembly is fixed on the fixed seat, and the upper end of the upper cover assembly covers the upper part of the movable grating; the chip assembly comprises angle chips, a processing chip and an interface chip, the angle chips, the processing chip and the interface chip are electrically connected with the circuit board assembly, and the angle chips are arranged in two groups and symmetrically correspond to the two sides of the rotating shaft assembly. And the fitted angle data can greatly improve the positioning precision of the encoder.

Description

Technical Field

[0001] The utility model relates to the field of absolute rotary encoders, in particular to a high-precision circular grating encoder. Background Art

[0002] An encoder is a device that converts angle or displacement information into electrical signals for transmission and communication. Encoders are primarily categorized as absolute and incremental rotary encoders. Compared to incremental encoders, absolute encoders have the advantage of requiring no counters and providing unique position data. Existing optical absolute encoders consist of a moving grating, an angle chip, and processing circuitry. The angle chip operates on a reflective principle, with the light source and optical receiver integrated into the same chip. When light shines on the moving grating, the chrome stripes on the grating reflect the light onto the optical detector. The moving grating is fixed to the encoder's main shaft. As the encoder shaft rotates, the moving grating rotates with it. The chip detects the changes in the grating stripes and interprets the optical signal into a digital signal, generating angular data corresponding to the position. However, misalignment is unavoidable during assembly of the moving grating. At locations with large deflection, the single light receiving element converts the optical signal into a digital signal, resulting in low positioning accuracy. This makes the encoder unsuitable for applications requiring high positioning accuracy. Therefore, a high-precision circular grating encoder is needed to address these issues. Utility Model Content

[0003] The purpose of the utility model is to provide a high-precision circular grating encoder to solve the problems mentioned in the background technology.

[0004] In order to achieve the above purpose, the present invention provides the following technical solutions:

[0005] A high-precision circular grating encoder includes a fixed base, a rotating shaft assembly, a circuit board assembly, a chip assembly, a moving grating, and an upper cover assembly. The rotating shaft assembly is rotatably mounted in the middle of the fixed base, the circuit board assembly is fixed above the fixed base, the chip assembly is fixed above the circuit board assembly and is electrically connected to the circuit board assembly, the moving grating is fixed to the power output end of the rotating shaft assembly and corresponds to the upper part of the chip assembly, the lower end of the upper cover assembly is fixed to the fixed base, and the upper end of the upper cover assembly covers the upper part of the moving grating;

[0006] The chip assembly includes an angle chip, a processing chip and an interface chip, all of which are electrically connected to the circuit board assembly. The angle chips are arranged in two groups and symmetrically correspond to the two sides of the shaft assembly. The processing chip is electrically connected to the two groups of angle chips respectively, and the interface chip is electrically connected to the processing chip.

[0007] Further description of the present invention: The fixing seat includes a mounting body, a spring piece and a mounting flange. The mounting body is fixed above the mounting flange by screws. The spring piece is arranged between the mounting body and the mounting flange. The shaft assembly is rotatably mounted on the mounting body.

[0008] Further description of the utility model: A first mounting groove, a second mounting groove and a wiring groove are provided at the upper end of the mounting body. The first mounting groove and the second mounting groove are symmetrically arranged on both sides of the rotating shaft assembly. The two ends of the wiring groove are respectively connected to the first mounting groove and the second mounting groove. The circuit board assembly is fixed to the mounting body through the first mounting groove and the second mounting groove.

[0009] Further description of the utility model: The circuit board assembly includes a first circuit board, a second circuit board and a connecting wire. The outer side of the first circuit board is fixed to the top of the installation body by screws, and the inner side of the first circuit board corresponds to the top of the first installation groove. The outer side of the second circuit board is fixed to the top of the installation body by screws, and the inner side of the second circuit board corresponds to the top of the second installation groove. The two ends of the connecting wire are electrically connected to the first circuit board and the second circuit board respectively, and the connecting wire corresponds to the wiring groove. The chip assembly is installed on the first circuit board and the second circuit board.

[0010] Further description of the utility model: The rotating shaft assembly includes a bearing, a rotating shaft body and a locking ring. The outer side of the bearing is fixed on the fixed seat, and the rotating shaft body is rotatably installed on the inner side of the bearing. The upper end of the rotating shaft body is provided with a limit ring protruding outward, and the limit ring corresponds to the top of the bearing. The inner side of the locking ring is connected to the outer periphery of the lower end of the rotating shaft body through a thread, and the locking ring corresponds to the bottom of the bearing. Two groups of bearings are arranged between the limit ring and the locking ring.

[0011] Further description of the utility model: The upper cover assembly includes an upper cover body and a sealing ring. The lower end of the upper cover body is fixed on the fixed seat, the upper end of the upper cover body covers the upper part of the moving grating, the inner end of the sealing ring is sleeved on the outer periphery of the upper end of the rotating shaft assembly, and the upper end surface of the sealing ring corresponds to the lower inner side of the upper cover body.

[0012] The beneficial effects of the present invention are as follows: the angle chip is based on a reflective principle, with the light source and optical receiving part integrated into the same chip. When light is irradiated on the moving grating, the chrome stripes of the moving grating emit light and project it onto the optical detection part. The moving grating is fixed to the encoder shaft assembly. When the shaft assembly rotates, the moving grating rotates accordingly. The angle chip detects the changes in the stripes on the moving grating and parses the light signal into a digital signal, thus forming angle data corresponding to the position. Two groups of angle chips are set and symmetrically placed on both sides of the shaft assembly. The angle data of the two groups of angle chips are read by the processing chip, and the two angle data are averaged and then packaged into the relevant communication protocol. After processing, they are sent to the host computer through the interface chip. The advantage of this design is that the two groups of angle chips are radially distributed, and the angle data obtained by the two light receiving elements are processed. The fitted angle data can greatly improve the positioning accuracy of the encoder. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is the overall structural diagram of the utility model;

[0014] Figure 2 It is a cross-sectional view of the utility model;

[0015] Figure 3 This is a partial structural diagram of the utility model (in which the circuit board assembly, chip assembly, dynamic grating and upper cover assembly are hidden);

[0016] Figure 4 This is a partial structural diagram of the utility model (where the dynamic grating and upper cover assembly are hidden);

[0017] Description of reference numerals:

[0018] 1. Fixing seat; 11. Mounting body; 111. First mounting slot; 112. Second mounting slot; 113. Wiring trough; 12. Spring clip; 13. Mounting flange; 2. Shaft assembly; 21. Bearing; 22. Shaft body;

[0019] 221. Limiting ring; 23. Locking ring; 3. Circuit board assembly; 31. First circuit board; 32. Second circuit board; 33. Connecting wire; 4. Chip assembly; 41. Angle chip; 42. Processing chip; 43. Interface chip; 5. Moving grating; 6. Upper cover assembly; 61. Upper cover body; 62. Sealing ring. DETAILED DESCRIPTION

[0020] The present invention will be further described below with reference to the accompanying drawings:

[0021] like Figures 1 to 4As shown, a high-precision circular grating encoder includes a fixed base 1, a rotating shaft assembly 2, a circuit board assembly 3, a chip assembly 4, a moving grating 5 and an upper cover assembly 6. The rotating shaft assembly 2 is rotatably mounted in the middle of the fixed base 1, the circuit board assembly 3 is fixed above the fixed base 1, the chip assembly 4 is fixed above the circuit board assembly 3 and is electrically connected to the circuit board assembly 3, the moving grating 5 is fixed to the power output end of the rotating shaft assembly 2 and corresponds to the upper part of the chip assembly 4. The lower end of the upper cover assembly 6 is fixed to the fixed base 1, and the upper end of the upper cover assembly 6 covers the upper part of the moving grating 5.

[0022] The chip assembly 4 includes an angle chip 41, a processing chip 42 and an interface chip 43, all of which are electrically connected to the circuit board assembly 3. The angle chips 41 are arranged in two groups and symmetrically correspond to the two sides of the shaft assembly 2. The processing chip 42 is electrically connected to the two groups of angle chips 41 respectively, and the interface chip 43 is electrically connected to the processing chip 42.

[0023] The angle chip 41 is reflective, with the light source and optical receiving part integrated into the same chip. When light shines on the moving grating 5, the chrome stripes on the moving grating 5 reflect the light and project it onto the optical detection part. The moving grating 5 is fixed to the encoder shaft assembly 2. When the shaft assembly 2 rotates, the moving grating 5 rotates accordingly. The angle chip 41 detects the changes in the stripes on the moving grating 5 and analyzes the light signal into a digital signal, thus forming angle data corresponding to the position. Two groups of angle chips 41 are set up and placed symmetrically on both sides of the shaft assembly 2. The processing chip 42 reads the angle data of the two groups of angle chips 41, takes the average of the two angle data, and then packages them into the relevant communication protocol. After processing, it is sent to the host computer through the interface chip 43. The advantage of this design is that the two groups of angle chips 41 are radially distributed, and the angle data obtained by the two light receiving elements are processed. The fitted angle data can greatly improve the encoder positioning accuracy.

[0024] The fixing base 1 includes a mounting body 11, a spring piece 12 and a mounting flange 13. The mounting body 11 is fixed above the mounting flange 13 by screws. The spring piece 12 is arranged between the mounting body 11 and the mounting flange 13. The shaft assembly 2 is rotatably mounted on the mounting body 11.

[0025] The mounting flange 13 is used to be fixed on a fixed part on the periphery of the rotating shaft to be measured. A spring piece 12 is provided between the mounting body 11 and the mounting flange 13 to play a role in shock absorption.

[0026] The upper end of the installation body 11 is provided with a first installation groove 111, a second installation groove 112 and a wiring groove 113. The first installation groove 111 and the second installation groove 112 are symmetrically arranged on both sides of the shaft assembly 2. The two ends of the wiring groove 113 are respectively connected to the first installation groove 111 and the second installation groove 112. The circuit board assembly 3 is fixed to the installation body 11 through the first installation groove 111 and the second installation groove 112.

[0027] The circuit board assembly 3 includes a first circuit board 31, a second circuit board 32 and a connecting wire 33. The outer side of the first circuit board 31 is fixed above the installation body 11 by screws, and the inner side of the first circuit board 31 corresponds to the top of the first installation groove 111. The outer side of the second circuit board 32 is fixed above the installation body 11 by screws, and the inner side of the second circuit board 32 corresponds to the top of the second installation groove 112. The two ends of the connecting wire 33 are electrically connected to the first circuit board 31 and the second circuit board 32 respectively. The connecting wire 33 corresponds to the wiring groove 113, and the chip assembly 4 is installed on the first circuit board 31 and the second circuit board 32.

[0028] By providing the first mounting groove 111 and the second mounting groove 112, the first circuit board 31 and the second circuit board 32 can be installed diametrically, that is, symmetrically installed on both sides of the shaft assembly 2. At the same time, the first circuit board 31 and the second circuit board 32 are fixed to the mounting body 11 by screws on the outside, and will not be blocked by the passive grating 5, which facilitates flexible disassembly and assembly of the circuit boards. Moreover, the first mounting groove 111 and the second mounting groove 112 can also provide heat dissipation space for the circuit boards.

[0029] The rotating shaft assembly 2 includes a bearing 21, a rotating shaft body 22 and a locking ring 23. The outer side of the bearing 21 is fixed on the fixed seat 1, and the rotating shaft body 22 is rotatably installed on the inner side of the bearing 21. The upper end of the rotating shaft body 22 is provided with a limiting ring 221 protruding outward, and the limiting ring 221 corresponds to the upper side of the bearing 21. The inner side of the locking ring 23 is connected to the outer periphery of the lower end of the rotating shaft body 22 through a thread, and the locking ring 23 corresponds to the lower side of the bearing 21. Two groups of bearings 21 are arranged between the limiting ring 221 and the locking ring 23.

[0030] The upper cover assembly 6 includes an upper cover body 61 and a sealing ring 62. The lower end of the upper cover body 61 is fixed on the fixed seat 1, and the upper end of the upper cover body 61 covers the upper part of the moving grating 5. The inner end of the sealing ring 62 is sleeved on the outer periphery of the upper end of the rotating shaft assembly 2, and the upper end surface of the sealing ring 62 corresponds to the lower inner side of the upper cover body 61.

[0031] The sealing ring 62 can effectively prevent dust from entering the encoder, thereby preventing dust from adversely affecting the encoder's detection results.

[0032] The above does not limit the technical scope of the present invention. Any modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A high-precision circular grating encoder, characterized by: The device comprises a fixed seat, a rotating shaft assembly, a circuit board assembly, a chip assembly, a dynamic grating, and an upper cover assembly. The rotating shaft assembly is rotatably mounted in the middle of the fixed seat. The circuit board assembly is fixed above the fixed seat. The chip assembly is fixed above the circuit board assembly and electrically connected to the circuit board assembly. The dynamic grating is fixed to the power output end of the rotating shaft assembly and corresponds to the upper part of the chip assembly. The lower end of the upper cover assembly is fixed to the fixed seat. The upper end of the upper cover assembly covers the upper part of the dynamic grating. The chip assembly includes an angle chip, a processing chip and an interface chip, all of which are electrically connected to the circuit board assembly. The angle chips are arranged in two groups and symmetrically correspond to the two sides of the shaft assembly. The processing chip is electrically connected to the two groups of angle chips respectively, and the interface chip is electrically connected to the processing chip.

2. A high-precision circular grating encoder according to claim 1, characterized in that: The fixing seat includes a mounting body, a spring piece and a mounting flange. The mounting body is fixed above the mounting flange by screws. The spring piece is arranged between the mounting body and the mounting flange. The shaft assembly is rotatably mounted on the mounting body.

3. A high-precision circular grating encoder according to claim 2, characterized in that: A first mounting groove, a second mounting groove and a wiring groove are provided at the upper end of the mounting body. The first mounting groove and the second mounting groove are symmetrically arranged on both sides of the rotating shaft assembly. The two ends of the wiring groove are respectively connected to the first mounting groove and the second mounting groove. The circuit board assembly is fixed to the mounting body through the first mounting groove and the second mounting groove.

4. The high-precision circular grating encoder according to claim 3, characterized in that: The circuit board assembly includes a first circuit board, a second circuit board and a connecting wire. The outer side of the first circuit board is fixed above the mounting body by screws, and the inner side of the first circuit board corresponds to the top of the first mounting groove. The outer side of the second circuit board is fixed above the mounting body by screws, and the inner side of the second circuit board corresponds to the top of the second mounting groove. The two ends of the connecting wire are electrically connected to the first circuit board and the second circuit board respectively. The connecting wire corresponds to the wiring groove, and the chip assembly is mounted on the first circuit board and the second circuit board.

5. The high-precision circular grating encoder according to claim 1, characterized in that: The rotating shaft assembly includes a bearing, a rotating shaft body and a locking ring. The outer side of the bearing is fixed on the fixed seat, and the rotating shaft body is rotatably installed on the inner side of the bearing. The upper end of the rotating shaft body is provided with a limiting ring protruding outward, and the limiting ring corresponds to the upper side of the bearing. The inner side of the locking ring is threadedly connected to the outer periphery of the lower end of the rotating shaft body, and the locking ring corresponds to the lower side of the bearing. The bearings are arranged in two groups between the limiting ring and the locking ring.

6. The high-precision circular grating encoder according to claim 1, characterized in that: The upper cover assembly includes an upper cover body and a sealing ring. The lower end of the upper cover body is fixed on the fixed seat, the upper end of the upper cover body covers the upper part of the dynamic grating, the inner end of the sealing ring is sleeved on the outer periphery of the upper end of the rotating shaft assembly, and the upper end surface of the sealing ring corresponds to the lower inner side of the upper cover body.

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