An absolute encoder

Abstract

The present application provides an absolute encoder. The absolute encoder provided by the present application includes a housing, a bottom cover and an operating shaft. A magnetic member is provided at the lower end of the operating shaft. A circuit board is provided between the bottom cover and the lower end of the operating shaft. A Hall sensor is mounted on the circuit board. The Hall sensor is located directly below the magnetic member. A seal is provided on the operating shaft, and the seal is in contact with the inner wall of the housing. The provided absolute encoder solves the problems of poor weather resistance, short service life, low resolution, etc. of the existing absolute encoders.

Description

Technical Field

[0001] This application relates to the technical field of encoders, and particularly to an absolute encoder. Background Art

[0002] A rotary encoder is an important sensor in industry for mechanical position angle, length, speed feedback and participation in control. Rotary encoders are divided into incremental encoders, absolute encoders, etc. Absolute encoders include single-turn absolute encoders, multi-turn absolute encoders, etc.

[0003] A single-turn absolute encoder is used to record the current position angle value within 360°. Even if the power is disconnected for a long time, this angle value will not be lost.

[0004] In the application scenarios of conventional single-turn absolute encoders, dust and liquid will enter the encoder. However, traditional single-turn absolute encoders do not have the functions of waterproof and dustproof, which easily cause damage to the encoder and greatly reduce its service life. In addition, traditional absolute encoders also have problems such as low resolution and easy internal friction affecting the service life.

[0005] Therefore, researching new types of absolute encoders has become an urgent problem for those skilled in the art. Summary of the Invention

[0006] In order to overcome the defects of the above-mentioned prior art, this application provides an absolute encoder to solve the problems of poor weather resistance, short service life, low resolution, etc. of existing absolute encoders.

[0007] This application provides an absolute encoder, which includes a housing, a bottom cover and an operating shaft; the housing is a hollow structure, the housing includes an upper opening provided at the upper end and a lower opening provided at the lower end; the bottom cover is provided at the lower end of the housing and covers the lower opening; the operating shaft is movably arranged inside the housing and extends out through the upper opening of the housing, and the operating shaft is configured to be axially rotatable around the axis of the operating shaft;

[0008] A magnetic member is provided at the lower end of the operating shaft; a circuit board is provided between the bottom cover and the lower end of the operating shaft, and a Hall sensor is installed on the circuit board, and the Hall sensor is located directly below the magnetic member;

[0009] A sealing member is provided on the operating shaft, and the sealing member is in contact with the inner wall of the housing.

[0010] Among them, the sealing member is used to seal the operating shaft to prevent liquid, dust, foreign objects, etc. from entering the interior of the housing.

[0011] In an alternative implementation, a receiving cavity is provided inside the main body portion, a through hole is provided in the mounting portion, and the through hole communicates with the receiving cavity; the upper opening is provided at the upper end of the mounting portion and communicates with the through hole; the lower opening is provided at the lower end of the main body portion;

[0012] The operating shaft includes a fixed portion and a shaft handle portion fixedly connected; the fixed portion is located inside the receiving cavity, and the magnetic member is fixedly provided on the fixed portion; the shaft handle portion passes through the through hole and extends out through the upper opening, the sealing member is sleeved on the shaft handle portion, and the sealing member is in contact with the inner wall of the through hole.

[0013] In an alternative implementation, an oil collecting groove for accommodating lubricating oil is provided on the outer wall of the operating shaft, and the oil collecting groove is located inside the through hole.

[0014] By providing the oil collecting groove, a continuous and long-term lubricating effect can be provided for the operating shaft, avoiding internal friction from affecting the service life.

[0015] In an alternative implementation, a diversion groove is provided on the outer wall of the operating shaft, the diversion groove is provided circumferentially along the outer wall of the operating shaft, and the diversion groove communicates with the oil collecting groove.

[0016] By providing the diversion groove, on the one hand, the lubricating oil in the oil collecting groove can be more evenly and fully distributed to the outer wall of the operating shaft, improving the lubricating effect; on the other hand, it can also accommodate foreign objects entering from the upper opening, avoiding damage to the operating shaft or the through hole caused by foreign objects.

[0017] In an alternative implementation, the depth of the oil collecting groove is greater than the depth of the diversion groove.

[0018] Setting the depth of the oil collecting groove to be greater than the depth of the diversion groove can make full use of the accommodating space of the oil collecting groove to collect and accommodate the foreign objects entering, better protect the inner surface of the absolute encoder, and improve the overall service life.

[0019] In an alternative implementation, a chip removal groove is provided on the outer surface of the mounting portion, and the chip removal groove communicates with the top end of the mounting portion.

[0020] By providing the chip removal groove, the chips, foreign objects, etc. generated at the top end of the mounting portion due to friction and other reasons can be guided and discharged by the chip removal groove, avoiding entering the inside of the absolute encoder.

[0021] According to the technical solutions provided by the foregoing implementations, the absolute encoder has at least the following advantages:

[0022] 1. By setting a seal, it can play a role in sealing and blocking the inside of the housing. When liquids, dust, foreign objects, etc. enter, they will be blocked by the seal and cannot enter the space where the Hall sensor is located, achieving a waterproof and dustproof effect and reaching the IP67 waterproof and dustproof level.

[0023] 2. By setting an oil sump and a diversion groove, the lubricating grease filled in the oil sump enters the diversion groove when the absolute encoder rotates, which can infiltrate the operating shaft and the through hole, playing a lubricating role. Especially when the lubricating grease in the diversion groove decreases, it has an automatic replenishment effect.

[0024] 3. By setting a chip removal groove, when the absolute encoder rotates, the chips or other foreign objects generated by the friction between the clamping part or other components and the top of the housing can be guided out by the chip removal groove, preventing them from entering the inside of the housing and extending the service life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 An exploded view of an absolute encoder provided by an embodiment of the present application;

[0027] Figure 2 A schematic diagram of an absolute encoder provided by an embodiment of the present application;

[0028] Figure 3 A front view of an absolute encoder provided by an embodiment of the present application;

[0029] Figure 4 is Figure 3 the A - A cross - sectional view;

[0030] Figure 5 A schematic diagram of an operating shaft provided by an embodiment of the present application;

[0031] Figure 6 is Figure 5 the exploded view of the operating shaft provided;

[0032] Figure 7 A schematic diagram of a housing provided by an embodiment of the present application;

[0033] Figure 8 is Figure 4 the enlarged view at M in;

[0034] Description of the reference numerals:

[0035] 1. Housing; 2. Bottom cover; 3. Operating shaft; 301. Seal; 4. Magnetic part; 5. Circuit board; 6. Hall sensor; 71. Clamping part; 72. Clamping ring groove; 73. Flat gasket; 8. Base;

[0036] 101. Upper opening; 102. Lower opening; 11. Main body part; 12. Installation part; 111. Accommodation cavity; 112. Bump; 121. Through hole; 122. Installation structure; 123. Chip removal groove; 31. Fixing part; 311. Annular groove; 312. Fixing groove; 32. Shaft handle part; 321. Fixed ring groove; 322. Oil collecting groove; 323. Diversion groove. Specific embodiments

[0037] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present application.

[0038] In this article, terms such as "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0039] In addition, in this article, orientation terms such as "upper" and "lower" are defined relative to the orientation of the structural schematic diagram in the accompanying drawings. It should be understood that these directional terms are relative concepts, and they are used for relative description and clarification, and they can change accordingly with the change of the orientation where the structure is placed.

[0040] Please refer to Figures 1 to 4 , an embodiment of the present application provides an absolute encoder, including a housing 1, a bottom cover 2 and an operating shaft 3; the housing 1 is a hollow structure, the housing 1 includes an upper opening 101 provided at the upper end and a lower opening 102 provided at the lower end; the bottom cover 2 is provided at the lower end of the housing 1 and covers the lower opening 102; the operating shaft 3 is movably provided inside the housing 1 and extends out through the upper opening 101 of the housing 1, and the operating shaft 3 is configured to be axially rotatable around the axis of the operating shaft 3;

[0041] A magnetic member 4 is provided at the lower end of the operating shaft 3; a circuit board 5 is provided between the bottom cover 2 and the lower end of the operating shaft 3, and a Hall sensor 6 is mounted on the circuit board 5, and the Hall sensor 6 is located directly below the magnetic member 4;

[0042] The operating shaft 3 is provided with a seal 301, and the seal 301 is in contact with the inner wall of the housing 1.

[0043] Among them, the seal 301 is used to seal the operating shaft 3 to prevent liquids, dust, foreign objects, etc. from entering the interior of the housing 1.

[0044] Specifically, please refer to Figure 4 and Figure 7 As shown, the housing 1 includes a main body portion 11 and a mounting portion 12, and the mounting portion 12 is provided on the upper end surface of the main body portion 11; a receiving cavity 111 is provided inside the main body portion 11, and the mounting portion 12 is provided with a through hole 121, and the through hole 121 communicates with the receiving cavity 111; the upper opening 101 is provided at the upper end of the mounting portion 12 and communicates with the through hole 121; the lower opening 102 is provided at the lower end of the main body portion 11;

[0045] Please refer to Figure 4 and Figure 5 As shown, the operating shaft 3 includes a fixed portion 31 and a shaft handle portion 32 that are fixedly connected; the fixed portion 31 is located inside the receiving cavity 111, and the magnetic member 4 is fixedly provided on the fixed portion 31; the shaft handle portion 32 passes through the through hole 121 and extends out through the upper opening 101, and the seal 301 is sleeved on the shaft handle portion 32, and the seal 301 is in contact with the inner wall of the through hole 121.

[0046] In this embodiment, the main body portion 11 is of a square structure, and the mounting portion 12 is of a columnar structure. In other embodiments, on the basis of having the receiving cavity 111 provided in this solution, the main body portion 11 can be set to other shape structures; on the basis of having the through hole 121 provided in this solution, the mounting portion 12 can be set to other shape structures.

[0047] In this embodiment, the through hole 121 is a circular through hole 121. To improve the product life, the inner wall of the through hole 121 can be set to a smooth surface to reduce friction. On the one hand, it can improve the smooth feel during rotation operation, and on the other hand, it can avoid the generation of foreign objects due to friction and affect the life of the product.

[0048] In this embodiment, the shaft handle portion 32 is of a cylindrical structure, which is adapted to the cross-sectional shape of the through hole 121, and the shaft handle portion 32 and the through hole 121 are in a clearance fit to avoid friction.

[0049] In this embodiment, the seal 301 is an O-ring, and the O-ring is sleeved on the operating shaft 3.

[0050] Specifically, the O-ring is made of elastic materials such as rubber and silica gel, and can be tightly sleeved on the operating shaft 3. In this embodiment, a fixing ring groove 321 is provided on the outer wall of the shaft handle portion 32, and the fixing ring groove 321 is used to sleeve the O-ring. The O-ring is in interference fit with the inner wall of the fixing ring groove 321 and the through hole 121 respectively. After installing the O-ring, the O-ring has a pre-pressure on the fixing ring groove 321 and the through hole 121. When foreign matters such as liquid or dust enter the through hole 121, they will be blocked by the O-ring and cannot enter the space where the Hall sensor 6 is located, achieving the waterproof and dustproof effect.

[0051] Specifically, the interference fit amount between the O-ring and the inner wall of the through hole 121 is set to 0.05 - 0.15 mm to control the pre-pressure. By setting this interference fit amount, not only can a good sealing effect be ensured, but also the rotational torque during the operation of the absolute encoder can be adjusted, achieving a good rotational damping effect.

[0052] Specifically, an oil collecting groove 322 for accommodating lubricating oil is provided on the outer wall of the operating shaft 3, and the oil collecting groove 322 is located inside the through hole 121. By providing the oil collecting groove 322, a continuous and long-term lubricating effect can be provided for the operating shaft 3, avoiding internal friction from affecting the service life. In this embodiment, the oil collecting groove 322 is provided on the outer wall of the shaft handle portion 32. The oil collecting groove 322 is a keyway structure and is arranged along the axial direction of the shaft handle portion 32.

[0053] Specifically, please refer to Figure 5 and Figure 6 As shown, a diversion groove 323 is provided on the outer wall of the operating shaft 3. The diversion groove 323 is arranged circumferentially along the outer wall of the operating shaft 3, and the diversion groove 323 is communicated with the oil collecting groove 322. By providing the diversion groove 323, on the one hand, the lubricating oil in the oil collecting groove 322 can be more evenly and fully distributed to the outer wall of the operating shaft 3, improving the lubricating effect; on the other hand, it can also accommodate foreign matters entering from the upper opening 101, avoiding damage to the operating shaft 3 or the through hole 121 caused by foreign matters.

[0054] In this embodiment, the diversion groove 323 is arranged circumferentially in a ring shape along the outer wall of the shaft handle portion 32. The oil collecting groove 322 is stacked on the diversion groove 323.

[0055] As Figure 8As shown, the groove depth D1 of the oil collecting groove 322 is greater than the groove depth D2 of the diversion groove 323. The groove depth dimension of the oil collecting groove 322 refers to the distance from the outer peripheral surface of the shaft handle portion 32 radially inward to the bottom surface of the oil collecting groove 322; similarly, the groove depth dimension of the diversion groove 323 refers to the distance from the outer peripheral surface of the shaft handle portion 32 radially inward to the bottom surface of the diversion groove 323.

[0056] Setting the groove depth of the oil collecting groove 322 to be greater than that of the diversion groove 323 can make full use of the accommodation space of the oil collecting groove 322 to collect and accommodate the foreign objects entering, better protect the inner surface of the absolute encoder, and improve the overall service life.

[0057] In this embodiment, in order to further achieve the effects of lubrication and foreign object collection simultaneously, the oil collecting groove 322 and the diversion groove 323 are arranged between the sealing ring and the upper opening 101.

[0058] When the absolute encoder is rotating, the foreign objects entering the through hole 121 will move to the diversion groove 323 under their own weight, rotation or other actions. The diversion groove 323 plays the role of distributing lubricating grease and collecting foreign objects; further, during the rotation process, since the groove depth of the oil collecting groove 322 is greater than that of the diversion groove 323, and the oil collecting groove 322 is superimposed on the diversion groove 323, when the foreign objects move to the position of the oil collecting groove 322 in the diversion groove 323, they will gradually accumulate in the oil collecting groove 322, thus achieving the effect of foreign object accumulation.

[0059] In this embodiment, in order to further achieve the effect of foreign object collection and accumulation, as Figure 5 shown, the width W1 of the oil collecting groove 322 is set to be greater than the width W2 of the diversion groove 323, so that when the lubricating grease in the diversion groove 323 moves to the oil collecting groove 322, due to the increased traveling width, the moving speed is reduced, and thus it is easier for foreign objects to accumulate in the oil collecting groove 322.

[0060] The width of the oil collecting groove 322 refers to the distance between the two ends of the groove of the oil collecting groove 322 along the axis direction of the shaft handle portion 32; similarly, the width of the diversion groove 323 refers to the distance between the two ends of the groove of the diversion groove 323 along the axis direction of the shaft handle portion 32.

[0061] Specifically, as Figure 7 shown, the outer surface of the mounting portion 12 is provided with a mounting structure 122. In this embodiment, the mounting structure 122 is a threaded structure for mounting and fixing external components, such as nut fixing parts, etc.

[0062] Specifically, please refer to Figures 4 to 7As shown, the absolute value encoder further includes a clamping member 71, the outer diameter of the clamping member 71 being greater than the aperture of the through hole 121; a clamping ring groove 72 is provided on the shaft handle portion 32, the clamping member 71 is clamped in the clamping ring groove 72, and the clamping member 71 is disposed at the top of the mounting portion 12.

[0063] In this embodiment, the clamping member 71 is a washer, and the outer diameter of the washer is set to be greater than the aperture of the through hole 121, so that when the washer is clamped in the clamping ring groove 72, the shaft handle portion 32 is restricted by the washer.

[0064] Since the shaft handle portion 32 needs to rotate during operation, and the washer is clamped in the clamping ring groove 72 of the shaft handle portion 32, it will rotate accordingly. Friction will be generated on the top of the mounting portion 12 during rotation, and thus friction debris may be generated.

[0065] To reduce the friction of the washer on the top of the mounting portion 12, in this embodiment, a flat washer 73 is further sleeved on the shaft handle portion 32, and the flat washer 73 is disposed between the top of the mounting portion 12 and the clamping member 71 for reducing the friction of the clamping member 71 on the mounting portion 12.

[0066] To enable the operating shaft 3 to be installed in the housing 1, in this application, the size of the fixing portion 31 is set to be greater than the aperture of the through hole 121. Specifically, the maximum dimension of the cross-section of the fixing portion 31 parallel to the radial plane of the shaft handle portion 32 is greater than the aperture of the through hole 121, and the fixing portion 31 abuts against the upper end surface of the accommodating cavity 111.

[0067] To make the rotation of the operating shaft 3 more stable, a ring groove 311 is provided on the upper end surface of the fixing portion 31, and a convex block 112 is provided on the top surface of the accommodating cavity 111, and the convex block 112 abuts against the ring groove 311; the center of the ring groove 311 coincides with the center of the shaft handle portion 32 in the projection plane perpendicular to the axis of the shaft handle portion 32.

[0068] In this embodiment, the convex block 112 is a ring-shaped convex block 112, and the ring-shaped convex block 112 is concentric with the ring groove 311 to improve the concentric stability during rotation.

[0069] In this embodiment, combined with Figure 7 As shown, a chip removal groove 123 is provided on the outer surface of the mounting portion 12, and the chip removal groove 123 is communicated with the top of the mounting portion 12 to guide and discharge the chips, foreign objects, etc. generated at the top of the mounting portion 12 due to friction and the like through the chip removal groove 123, so as to prevent them from entering the absolute value encoder.

[0070] Specifically, the chip removal groove 123 is arranged downward along the outer surface of the mounting portion 12.

[0071] In this embodiment, a base 8 is arranged between the bottom cover 2 and the circuit board 5, and the base 8 is used to support the circuit board 5.

[0072] In this embodiment, the bottom cover 2 is fixed to the housing 1 through a snap-fit structure. In other embodiments, fixing methods such as adhesive fixing and bolt fixing can be used for fixing.

[0073] In this embodiment, the circuit board 5 is provided with an interface for signal transmission with the outside.

[0074] In this embodiment, in combination Figure 4 As shown, the fixing portion 31 is provided with a fixing groove 312, and the magnetic member 4 is fixed in the fixing groove 312. In this embodiment, epoxy resin is used for potting and fixing to avoid the influence of the magnetic conductor in the screw fixing method and other methods on the magnetic field and affect the resolution of the absolute encoder.

[0075] At the same time, in order to improve the resolution of the absolute encoder, the housing 1 is integrally die-cast from metal, so as to form a shielding effect between the Hall sensor 6 and the outside world, prevent external interference, and improve the signal stability between the Hall sensor 6 and the magnetic member 4.

[0076] This application has at least one of the following advantages:

[0077] 1. By providing a sealing member, it can play a sealing and blocking role inside the housing. When liquid, dust, foreign objects, etc. enter, they will be blocked by the sealing member and cannot enter the space where the Hall sensor is located, achieving a waterproof and dustproof effect, and can reach the IP67 waterproof and dustproof level.

[0078] 2. By providing an oil sump and a diversion groove, the lubricating grease filled in the oil sump enters the diversion groove when the absolute encoder rotates, and can infiltrate the operating shaft and the through hole to play a lubricating role. Especially when the lubricating grease in the diversion groove decreases, it can play an automatic replenishment effect;

[0079] 3. By providing a chip removal groove, when the absolute encoder rotates, the chips or other foreign objects generated by the friction between the clamping member or other components and the top of the housing can be guided out by the chip removal groove, avoiding entering the inside of the housing and improving the service life of the product.

[0080] 4. The housing is integrally die-cast from metal, forming a shielding effect between the Hall sensor and the outside world, preventing external interference, and improving the signal stability between the Hall sensor and the magnetic member, which is beneficial to improving the resolution of the absolute encoder.

[0081] The above has introduced in detail the absolute encoder provided by the embodiments of the present application, and specific embodiments have been used to explain the principle and implementation manner of the present application. The above description is only used to help understand the method and its core mechanism of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific embodiments and the scope of application. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. An absolute encoder, characterized in that: The absolute encoder includes a housing, a bottom cover, and an operating shaft; the housing is a hollow structure, the housing includes an upper opening provided at the upper end and a lower opening provided at the lower end; the bottom cover is provided at the lower end of the housing and covers the lower opening; the operating shaft is movably provided inside the housing and extends out through the upper opening of the housing, and the operating shaft is configured to be axially rotatable about the axis of the operating shaft. A magnetic member is provided at the lower end of the operating shaft; a circuit board is provided between the bottom cover and the lower end of the operating shaft, and a Hall sensor is installed on the circuit board, and the Hall sensor is located directly below the magnetic member. A seal is provided on the operating shaft, and the seal is in contact with the inner wall of the housing. The housing includes a main body portion and a mounting portion, and the mounting portion is provided on the upper end surface of the main body portion; a receiving cavity is provided inside the main body portion, a through hole is provided in the mounting portion, and the through hole communicates with the receiving cavity; the upper opening is provided at the upper end of the mounting portion and communicates with the through hole; the lower opening is provided at the lower end of the main body portion. The operating shaft includes a fixed portion and a shaft handle portion that are fixedly connected; the fixed portion is located inside the receiving cavity, and the magnetic member is fixedly provided on the fixed portion; the shaft handle portion passes through the through hole and extends out through the upper opening, the seal is sleeved on the shaft handle portion, and the seal is in contact with the inner wall of the through hole. An oil collecting groove for accommodating lubricating oil is provided on the outer wall of the operating shaft, and the oil collecting groove is located inside the through hole. A diversion groove is provided on the outer wall of the operating shaft, the diversion groove is provided circumferentially along the outer wall of the operating shaft, and the diversion groove communicates with the oil collecting groove; the diversion groove is used for evenly distributing the lubricating oil while accommodating foreign matters entering from the upper opening. The absolute encoder further includes a clamping member, and the outer diameter of the clamping member is greater than the aperture of the through hole.

2. The absolute encoder according to claim 1, wherein: The oil collecting groove and the diversion groove are provided between the seal and the upper opening.

3. The absolute encoder according to claim 2, characterized in that: The depth of the oil collecting groove is greater than the depth of the diversion groove.

4. The absolute encoder according to claim 1, characterized in that: A clamping ring groove is provided on the shaft handle portion, the clamping member is clamped in the clamping ring groove, and the clamping member is provided at the top of the mounting portion.

5. The absolute value encoder according to claim 3, characterized in that: The maximum dimension of the cross section of the fixed portion parallel to the radial plane of the shaft handle portion is greater than the aperture of the through hole, and the fixed portion abuts against the upper end surface of the receiving cavity.

6. The absolute encoder according to claim 3, characterized in that: An annular groove is provided on the upper end surface of the fixed portion, a convex block is provided on the top surface of the receiving cavity, and the convex block abuts against the annular groove; the center of the annular groove coincides with the center of the shaft handle portion in the projection plane perpendicular to the axis of the shaft handle portion.

7. The absolute encoder according to claim 3, characterized in that: A chip removal groove is provided on the outer surface of the mounting portion, and the chip removal groove communicates with the top of the mounting portion.

Images