Robot joint encoder module

Abstract

The utility model discloses a robot joint encoder module. The robot joint encoder module mainly comprises a shaft connecting piece, an encoding disc, a decoding deck fixing piece, a decoding deck, a bearing and a flexible mounting seat. The shaft connecting piece is sleeved on an output shaft of the robot joint motor, and the coding disc is installed at the front end of the shaft connecting piece. The decoding deck fixing piece is located on the periphery of the shaft connecting piece, and the decoding deck is installed at the front end of the decoding deck fixing piece and used in cooperation with the coding disc. And the bearing is connected between the shaft connecting piece and the decoding deck fixing piece. And the flexible mounting seat is mounted between the decoding deck fixing piece and the shell of the robot joint and is made of an elastomer material. According to the robot joint, the relative positions of the coding disc and the decoding deck are fixed, the structure is stable, and data signals are accurate and reliable. The decoding deck fixing piece is connected with the joint shell through the flexible installation base, the radial displacement and the axial displacement between the decoding deck and the output shaft are buffered, the circumferential displacement trend between the decoding deck and the output shaft is resisted, and the reading precision and the structural stability of the encoder are improved.

Description

Technical Field

[0001] The utility model relates to a robot joint position detection system, in particular to a robot joint encoder module, belonging to the technical field of encoders. Background Art

[0002] In recent years, robots have played an increasingly important role in intelligent manufacturing. Encoders are widely used in industrial robots and collaborative robots to achieve high-precision motion control and timely detection of the position of each joint.

[0003] An encoder is a sensing device that provides motion feedback. It converts motion information into electrical signals and feeds them back to the control system. The controller uses these signals to determine the position, speed, or direction of the motion mechanism and sends specific commands to control the joint. Encoders consist of an encoder disk and a decoder board. They have the following structures and installation options:

[0004] (1) Encoders currently on the market typically mount the encoder disc on the output shaft of a robot joint, while the decoder board is fixed to the joint housing. During robot operation, the output shaft will bend and deform as the load changes, causing the encoder disc to change significantly, while the decoder board remains fixed. When the relative positions of the encoder disc and decoder board change significantly, the encoder's reading accuracy decreases, and the reading may even fail.

[0005] The above installation form (1) is to directly install the encoder disk on the shaft and fix the decoder board on the joint housing. Although the structure is simple, the relative position of the encoder disk and the decoder board cannot be guaranteed, resulting in possible failure of the encoder reading.

[0006] (2) In the encoder module and robot joint patent CN202210104338.6, Zhai Jiaxin et al. connected the mounting flange to the shaft, mounted the encoder disc on the mounting flange, and mounted the decoder board on the decoder board mounting seat. A bearing was pressed into the annular decoder board mounting seat and the mounting flange by applying glue to maintain the relative position of the encoder disc and the decoder board. A flexible buffer portion was provided between the decoder board mounting seat and the joint housing to accommodate changes in the relative position between the decoder board mounting seat and the joint housing.

[0007] The above-mentioned installation form (2) connects the mounting flange to the shaft, fixes the encoder disc on the mounting flange, provides a bearing between the decoder plate and the mounting flange, and provides a flexible buffer portion between the decoder plate mounting seat and the joint housing. To a certain extent, the relative position between the decoder plate and the encoder disc is maintained. However, the connection between the decoder plate and the mounting flange and the bearing is glued and pressed, which is inconvenient to install and remove and not conducive to maintenance. The structural rigidity of the flexible buffer portion between the decoder plate mounting seat and the housing is not high, and the stress concentration is relatively obvious. When the encoder module moves axially relative to the housing, it is easy to produce plastic deformation or even breakage. Moreover, after plastic deformation, the rigidity of the component in all directions will change significantly, seriously affecting the working accuracy of the encoder module. Although the elasticity of the flexible buffer portion can be used to compensate for the radial relative motion between the decoder plate mounting seat and the housing, the rigidity of the decoder plate mounting seat in the circumferential motion direction is insufficient, which is easy to produce circumferential vibration during the movement of the robot, thereby affecting the accuracy of the encoder reading. Utility Model Content

[0008] The technical problem to be solved by the utility model is that the decoder board easily generates circumferential vibration during the movement of the robot, thereby affecting the accuracy of the encoder reading.

[0009] In order to solve the above technical problems, the present invention provides an encoder module structure for robot joints, which can improve the measurement accuracy and structural stability. The technical solution is as follows:

[0010] A robot joint encoder module, comprising:

[0011] A shaft connector, which is sleeved on the output shaft of the robot joint motor;

[0012] A code disc mounted on the front end of the shaft connector;

[0013] A decoder board fixing member, which is located on the periphery of the shaft connecting member;

[0014] The decoder board is installed at the front end of the decoder board fixing part and is used in conjunction with the encoder disk;

[0015] A bearing connected between the shaft connecting member and the decoder board fixing member;

[0016] A flexible mounting seat is installed between the decoder board fixing piece and the housing of the robot joint, and the flexible mounting seat is made of an elastomer material;

[0017] The flexible mounting seat is configured to buffer the axial position offset and radial position offset of the decoder board fixing piece relative to the output shaft, and to resist the circumferential position offset trend of the decoder board fixing piece relative to the output shaft.

[0018] In some embodiments, the robot joint encoder module further includes a housing connector, which is located between the robot joint housing and the flexible mounting seat.

[0019] In some embodiments, the flexible mount is composed of two or more sector ring sub-sections; alternatively, the flexible mount is a single ring-shaped flexible mount.

[0020] In some embodiments, the flexible mounting seat is composed of two sector ring sub-portions and is symmetrically distributed about the center, and the arc of each sector ring sub-portion is 120°.

[0021] In some embodiments, a first surface of the flexible mounting base is fixedly connected to the decoder board fixing member, and a second surface of the flexible mounting base is fixedly connected to the housing connector.

[0022] In some embodiments, the first surface and the second surface are upper and lower bottom surfaces of the flexible mounting base, respectively.

[0023] In some embodiments, the decoder board fixing member is fixed to the upper bottom surface of the flexible mounting seat by means of a plurality of first bolts; and the housing connector is fixed to the lower bottom surface of the flexible mounting seat by means of a plurality of second bolts.

[0024] In some embodiments, the decoder board fixing member has a plurality of first latches, and the upper bottom surface of the flexible mounting seat has a plurality of first mounting holes, and the first mounting holes match the shape and number of the first latches;

[0025] The shell connector is provided with a plurality of second latches, and the lower bottom surface of the flexible mounting seat is provided with a plurality of second mounting holes, and the second mounting holes match the shapes and the numbers of the second latches.

[0026] In some embodiments, the robot joint encoder module further includes:

[0027] An inner fastener, which is used to securely connect the shaft connector to the inner ring of the bearing;

[0028] The outer fastener is used to securely connect the decoder board fixing member to the outer ring of the bearing.

[0029] In some embodiments, the shaft connecting member is provided with a first mounting position matching the inner ring of the bearing, and the inner fastener is a first annular metal member; the inner fastener is fixed to the shaft connecting member by bolts so that the inner ring of the bearing is clamped in the first mounting position;

[0030] The decoder board fixing piece is provided with a second mounting position matching the outer ring of the bearing, and the outer fastener adopts a second annular metal piece; the outer fastener is fixed to the decoder board fixing piece by bolts so that the outer ring of the bearing is clamped in the second mounting position.

[0031] The beneficial effects of this utility model are as follows: The robot joint encoder module of this utility model has a fixed relative position between the encoder disk and the decoder board, a stable structure, and accurate and reliable data signals. The decoder board is fixed to the decoder board fixture, which is connected to the joint housing via a flexible mounting seat. This cushions radial and axial displacement between the decoder board and the output shaft, resists circumferential displacement between the decoder board and the output shaft, and improves the accuracy of the encoder reading and the stability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a schematic diagram of the overall structure of a robot joint encoder module provided by a preferred embodiment of the present utility model.

[0033] Figure 2 yes Figure 1 The diagram shows the structure of the robot joint encoder module viewed from the inside.

[0034] Figure 3 yes Figure 1 The cross-sectional structure diagram of the robot joint encoder module is shown in FIG.

[0035] Figure 4 yes Figure 1 The isotropic definition diagram of the robot joint encoder module shown in .

[0036] The meanings of the reference numerals in the above figures are as follows:

[0037] 110 output shaft

[0038] 210 shaft connector

[0039] 220 Bearing inner fastener

[0040] 310 bearing inner ring

[0041] 320 bearing outer ring

[0042] 410 decoder board fixing parts

[0043] 420 Bearing Outboard Fastener

[0044] 510 encoder disk

[0045] 520 decoder board

[0046] 610 flexible mounting seat first subsection

[0047] 620 flexible mounting seat second subsection

[0048] 710 housing connector DETAILED DESCRIPTION

[0049] As used in this specification and claims, "first," "second," and similar terms do not denote any order, quantity, or importance, but are used only to distinguish one component from another. "A" or "an," and similar terms do not denote a limitation of quantity, but rather denote the presence of at least one. In the description of this patent, unless otherwise specified, "plurality" means two or more.

[0050] In the description of this patent, words such as "including" or "having" and the like mean that the elements or objects appearing before "including" or "having" include the elements or objects listed after "including" or "having" and their equivalent elements, and do not exclude other elements or objects.

[0051] In the description of this patent, when an element is referred to as being "fixed to / mounted on (or similar terms)" another element, it may be directly on the other element or there may be intervening elements. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or there may be intervening elements at the same time. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements.

[0052] In the description of this patent, the terms "front", "back", "up", "down", "left", "right", "horizontal", "transverse", "longitudinal", "top", "bottom", "inside", "outside", "clockwise", "axial", "radial", "circumferential", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, they should not be understood as limitations on this patent.

[0053] The radial, axial and circumferential directions of the present invention are as follows Figure 4 The method definition in .

[0054] In order to ensure the accuracy of encoder measurement and the stability of the structure, through analysis of similar existing technologies, it is necessary to design the structure of the traditional robot joint encoder module to ensure the relative position of the encoding disk and the decoder board, buffer and compensate the radial and axial displacement between the decoder board and the robot joint housing, fix the circumferential movement of the decoder board, and improve the accuracy of the encoder reading and the stability of the structure.

[0055] In order to solve the problem that the relative position of the encoding disk and the decoder plate of the traditional robot joint encoder module may change, resulting in inaccurate readings, the utility model redesigns the robot joint encoder module, including improvements in the connection between the decoder plate and the encoding disk bearing and the flexible connection between the decoder plate and the joint housing.

[0056] The specific approach is as follows: (1) The decoder board and the encoder disk are connected by a deep groove ball bearing, which only requires bolts to tighten and fix, ensuring that the relative position of the decoder board and the encoder disk remains unchanged. The relative position between the two can be unaffected by shaft deformation, thereby improving the accuracy of encoder measurement. (2) The decoder board is fixed on the decoder board fixing part, and an annular flexible mounting seat is used to connect the decoder board fixing part and the joint housing to buffer the radial and axial displacement between the decoder board and the housing, fix the circumferential movement of the decoder board, and compensate for the relative position change between the decoder board and the housing. Further, the accuracy of the encoder reading and the stability of the structure are improved. The installation method of the bearing and the annular flexible mounting seat is bolt fixing, which can ensure the stability and easy maintenance of the structure.

[0057] A preferred embodiment of the above technical solution is described in detail below with reference to the accompanying drawings.

[0058] Figures 1 to 3 This is a schematic diagram of a robot joint encoder module provided by a preferred embodiment of the present invention. The encoder module is assembled on the output shaft of the robot joint motor. The encoder module is designed to be separate from the robot joint, facilitating installation and maintenance. The encoder module includes: an output shaft 110, a shaft connector 210, a bearing 300, a decoder board fixing member 410, an inner bearing fastener 220, an outer bearing fastener 420, an encoder disc 510, a decoder board 520, a housing connector 710, a first flexible mounting base subsection 610, and a second flexible mounting base subsection 620.

[0059] like Figure 3 As shown, the shaft connector 210 is directly mounted on the front of the joint motor's output shaft 110 and secured thereto. The decoder board fixture 410 is located on the periphery of the shaft connector 210. The bearing 300 is mounted between the shaft connector 210 and the decoder board fixture 410. Preferably, the bearing 300 is a deep groove ball bearing. The deep groove ball bearing consists of an inner bearing ring 310, an outer bearing ring 320, a set of steel balls (not shown), and a retaining cage (not shown).

[0060] The outer surface of the shaft connector 210 features a recessed area whose shape and dimensions match those of the bearing inner ring 310. The bearing inner ring 310 is positioned within this recessed area. The shaft connector 210 and the bearing inner ring 310 are secured by a bearing inner fastener 220. The bearing inner fastener 220 is an annular structure and is mounted to the shaft connector 210 using a set of bolts. Together, the shaft connector 210 and the bearing inner fastener 220 clamp the bearing inner ring 310, thus constraining the position of the bearing 300 and facilitating assembly, disassembly, and maintenance.

[0061] The decoder board fixture 410 has a recessed area on its inner side, matching the shape and dimensions of the bearing outer ring 320. The bearing outer ring 320 is located in this recessed area. The decoder board fixture 410 is secured to the bearing outer ring 320 by the bearing outer fastener 420. The bearing outer fastener 420 is an annular structure and is attached to the decoder board fixture 410 using a set of bolts. The decoder board fixture 410 and the bearing outer fastener 420 clamp the bearing outer ring 320 together, thus constraining the position of the bearing 300 and facilitating assembly, disassembly, and maintenance.

[0062] The encoder disk 510 is mounted on the shaft connector 210, and the decoder board 520 is mounted on the decoder board fixture 410. The decoder board 520 and encoder disk 510 cooperate to perform readings. The bearing 300 is used to maintain the relative position of the encoder disk 510 and decoder board 520 during the rotation of the output shaft 110. This ensures that the relative position of the decoder board 520 and encoder disk 510 is not affected by deformation of the output shaft 110, thereby improving the accuracy of the encoder readings.

[0063] The housing connector 710 is fixedly connected to the robot joint housing. The flexible mounting base is bolted to the housing connector 710, facilitating disassembly and repair, enhancing structural stability and maintainability. The flexible mounting base ensures the relative position of the encoder disk 510 and decoder board 520. This structure maintains its original properties and functionality even when plastically deformed.

[0064] The flexible mounting base is made of an elastomeric material such as soft rubber. This is not limited to TPE soft rubber; other elastomeric materials can be used. The elastomeric material should have an appropriate hardness. If it is too hard, it may easily cause the bearing 300 to jam during assembly, while if it is too soft, it may cause significant circumferential displacement of the encoder module.

[0065] The flexible mounting base must follow the design principle of the thickest structure in the circumferential direction. Figure 1 As shown, the flexible mount is designed as an annular block structure, which consists of two parts: a first flexible mount sub-section 610 and a second flexible mount sub-section 620. The arc of the first flexible mount sub-section 610 and the second flexible mount sub-section 620 should be 120 degrees and symmetrically distributed to ensure uniform stress distribution between the flexible mount and the joint housing.

[0066] The front end surface of the housing connector 710 is provided with a plurality of screw holes, which are parallel to the axial direction of the output shaft 110. The first sub-section 610 of the flexible mounting seat and the second sub-section 620 of the flexible mounting seat are fixed to the housing connector 710 by bolts. A plurality of long bolts are used to penetrate the first sub-section 610 of the flexible mounting seat and the second sub-section 620 of the flexible mounting seat until they reach the screw holes of the housing connector 710 and are fixed. Figure 1Taking the second sub-section 620 of the flexible mounting seat as an example, four through holes are provided near the outer circumference of the second sub-section 620 of the flexible mounting seat, and the direction of the through holes is parallel to the axial direction of the output shaft 110. After the bolts are inserted into the through holes, they can be in close contact with the inner wall of the hole, so that the outer side of the second sub-section 620 of the flexible mounting seat is fixed to the shell connector 710. Similarly, a plurality of axial through holes (not shown in the figure) are also provided near the inner circumference of the second sub-section 620 of the flexible mounting seat. The bolts are inserted into these through holes axially from back to front, and then reach the screw holes (not shown in the figure) of the decoder board fixing member 410 and are fixed. The inner side of the second sub-section 620 of the flexible mounting seat is fixed to the decoder board fixing member 410.

[0067] In other embodiments, latches can be provided on the decoder board fixing member 410 and the housing connecting member 710, respectively, and inserted into the holes of the flexible mounting base. These latches replace bolts and screw holes, making installation more convenient. In other embodiments, the decoder board fixing member 410 and the housing connecting member 710 can be fixed to the inner and outer circumferences of the flexible mounting base, respectively.

[0068] When the joint motor output shaft 110 rotates, it drives the encoder disk 510 to rotate. Because the output shaft 110 may be deformed due to the load, the position of the encoder disk 510 may change accordingly. The bearing 300 installed between the shaft connector 210 and the decoder plate fixing member 410 can prevent the relative position of the encoder disk 510 and the decoder plate 520 from changing, so that the encoder reading is always accurate. On the other hand, because the shaft connector 210 and the decoder plate fixing member 410 are connected by the bearing 300, when the shaft connector 210 rotates at high speed with the output shaft 110, the decoder plate fixing member 410 will inevitably have a certain rotation tendency in the circumferential direction. If the decoder plate fixing member 410 rotates slightly, it will cause the encoder reading to be inaccurate, so the decoder plate fixing member 410 and the decoder plate 520 must be relatively fixed.

[0069] The decoder board fixing part 410 and the shell connecting part 710 are connected and fixed via a flexible mounting seat. The shell connecting part 710 serves as a connecting intermediary between the flexible mounting seat and the robot joint housing, making the flexible mounting seat easier to configure and install. The flexible mounting seat has appropriate hardness and softness, which can ensure that the decoder board 520 can adjust its posture as the position of the encoder disk 510 changes, and buffer and compensate for the radial and axial displacement between the decoder board 520 and the output shaft 110 of the robot joint motor. The decoder board fixing part 410 and the shell connecting part 710 are fixed by the first sub-part 610 of the flexible mounting seat and the second sub-part 620 of the flexible mounting seat. The shell connecting part 710 is fixed to the robot joint housing, and the decoder board 520 is fixedly mounted on the decoder board fixing part 410. In this way, the decoder board 520 is relatively fixed to the robot joint housing and cannot move circumferentially, thereby improving the accuracy of the encoder reading and the stability of the structure.

[0070] In other embodiments, the flexible mounting base is a single annular flexible mounting base, which is a complete annular shape. For ease of installation, the annular flexible mounting base is provided with a disconnection opening. After the annular mounting base is unfolded from the disconnection opening, the flexible mounting base can be more conveniently installed in place.

[0071] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art based on the concepts of the present invention through logical analysis, reasoning, or limited experimentation based on the existing technology should be within the scope of protection defined by the claims.

Claims

1. A robot joint encoder module, characterized in that: include: A shaft connector, which is sleeved on the output shaft of the robot joint motor; an encoding disc mounted on the front end of the shaft connecting member; a decoder board fixing member, which is located on the periphery of the shaft connecting member; A decoder board, which is mounted on the front end of the decoder board fixing member and is used in conjunction with the encoder disk; a bearing connected between the shaft connecting member and the decoder board fixing member; A flexible mounting seat, which is installed between the decoder board fixing piece and the housing of the robot joint, and the flexible mounting seat is made of an elastomer material; The flexible mounting seat is configured to buffer axial and radial position offsets of the decoder plate fixing member relative to the output shaft, and to resist circumferential position offset trends of the decoder plate fixing member relative to the output shaft.

2. The robot joint encoder module according to claim 1, characterized in that: Also included is a housing connector located between the robot joint housing and the flexible mounting seat.

3. The robot joint encoder module according to claim 2, characterized in that: The flexible mounting seat is composed of two or more fan-shaped sub-parts; or, the flexible mounting seat is a single ring-shaped flexible mounting seat.

4. The robot joint encoder module according to claim 3, characterized in that: The flexible mounting seat is composed of two fan-shaped sub-parts and is symmetrically distributed around the center, and the arc of each fan-shaped sub-part is 120°.

5. The robot joint encoder module according to claim 3, characterized in that: The first surface of the flexible mounting seat is fixedly connected to the decoder board fixing piece, and the second surface of the flexible mounting seat is fixedly connected to the shell connector.

6. The robot joint encoder module according to claim 5, characterized in that: The first surface and the second surface are respectively the upper and lower bottom surfaces of the flexible mounting base.

7. The robot joint encoder module according to claim 6, characterized in that: The decoder board fixing member is fixed to the upper bottom surface of the flexible mounting seat by means of a plurality of first bolts; the shell connector is fixed to the lower bottom surface of the flexible mounting seat by means of a plurality of second bolts.

8. The robot joint encoder module according to claim 6, characterized in that: The decoder board fixing member has a plurality of first latches, and the upper bottom surface of the flexible mounting seat has a plurality of first mounting holes, and the shape and number of the first mounting holes match those of the first latches; The shell connector has a plurality of second pins, and the lower bottom surface of the flexible mounting seat has a plurality of second mounting holes, and the second mounting holes match the shape and number of the second pins.

9. The robot joint encoder module according to claim 1, characterized in that: Also includes: an inner fastener for fixedly connecting the shaft connector to the inner ring of the bearing; An outer fastener is used to securely connect the decoder board fixing member to the outer ring of the bearing.

10. The robot joint encoder module according to claim 9, characterized in that: The shaft connecting member is provided with a first mounting position matching the inner ring of the bearing, and the inner fastener is a first annular metal member; the inner fastener is fixed to the shaft connecting member by bolts so that the inner ring of the bearing is clamped in the first mounting position; The decoder board fixing piece is provided with a second mounting position matching the outer ring of the bearing, and the outer fastener is a second annular metal piece; the outer fastener is fixed to the decoder board fixing piece by bolts so that the outer ring of the bearing is clamped in the second mounting position.

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