Constant force float for robots

Abstract

The utility model discloses a constant force floating device for robot, including the casing and the integrated axial constant force floating structure, radial constant force floating structure and radial floating locking structure. Axial constant force floating structure drives piston through axial air cylinder, and realizes axial constant force compensation with radial limit block and elastic part. Radial constant force floating structure supports main shaft through joint bearing, and by the circumferential array's radial air cylinder abuts the bearing inner ring, realizes radial universal swing and constant force output. Radial floating locking structure sets up the main shaft end through locking air cylinder drive piston with limit groove, realizes radial rigid locking. The utility model integrates the initiative constant force floating function of axial and radial, and can switch to rigid locking state quickly, and effectively promotes the self -adaptation ability, process stability and operating efficiency of robot in polishing, deburring and other complex force control operation.

Description

Technical Field

[0001] This utility model relates to the technical field of constant force floating devices for robot end effectors, and more particularly to a constant force floating device for robots. Background Technology

[0002] In the field of industrial robots, floating devices are key components for achieving precision force control operations (such as grinding, polishing, deburring, and precision assembly). Installed between the end effector of the robot arm and the tool, they can automatically compensate for the position and shape tolerances of the workpiece and the trajectory errors of the robot, maintaining a constant contact force between the tool and the workpiece, thereby ensuring stable process quality and protecting the equipment from impact damage.

[0003] However, existing floating devices still have significant limitations. First, most devices are single-function, providing only axial or radial floating, making it difficult to handle errors occurring simultaneously in multiple directions during the machining of complex curved surfaces. Second, traditional passive floating devices rely on springs or air cushions to provide pressure, and their output force fluctuates with changes in compression, making it difficult to achieve true "constant force" control and affecting machining consistency. Furthermore, the lack of an effective locking mechanism to rigidify the floating mechanism during robot idle movements or when precise positioning is required leads to tool-end wobbling, affecting motion accuracy and stability during non-operational times.

[0004] Therefore, existing technologies need to be improved and developed. Utility Model Content

[0005] In view of the above-mentioned defects in the prior art, the purpose of this utility model is to provide a constant force floating device for robots, so as to solve the technical problem that the existing constant force floating devices for robots lack an effective rigid locking mechanism when not in operation.

[0006] To achieve the above objectives, this utility model proposes a constant force floating device for robots, comprising an axial constant force floating structure, a radial constant force floating structure, a radial floating locking structure, and a housing. The axial constant force floating structure includes: an axial cylinder assembly, comprising an axial mounting seat and an axial cylinder fixedly mounted within the axial mounting seat, the axial mounting seat being fixed within the housing; an axial piston, disposed on the axial cylinder, capable of axial movement under its drive; a radial limiting block, fixed within the housing, located at the end of the axial piston away from the axial cylinder, the radial limiting block having a through limiting hole, the diameter of the limiting hole matching the diameter of the axial piston, the axial piston being axially slidable within the limiting hole, an elastic element provided between the radial limiting block and the axial mounting seat; and a robot arm connecting flange fixedly connected to the radial limiting block. The radial constant force floating structure includes: a main shaft, a joint bearing, and a radial constant force cylinder assembly; the fixed outer ring of the joint bearing is fixed to the housing, and its movable inner ring is fixedly connected to the main shaft, allowing the main shaft to omnidirectionally rotate. The main shaft is oscillatingly mounted within the housing; the axial mounting seat has a movable hole at its end away from the axial cylinder, and one end of the main shaft extends into the movable hole, the diameter of which is larger than the outer diameter of the main shaft; the radial constant force cylinder assembly includes a radial mounting seat, a radial cylinder, and a radial piston; the radial mounting seat is arranged around the main shaft and fixedly connected to the housing, and has a plurality of vertical mounting holes arranged circumferentially on its end face facing the spherical bearing; the radial cylinder is located in the vertical mounting holes and can drive the radial piston to move axially, so that the end of the radial piston is aligned with the spherical bearing. The bottom of the movable inner ring of the bearing abuts against each other; the radial floating locking structure includes: a locking cylinder, which is fixedly mounted on the axial mounting seat and communicates with the movable hole; a locking piston, which is slidably disposed in the movable hole and driven by the locking cylinder to move axially along the movable hole; the end of the locking piston is provided with a limiting groove, the inner diameter of the limiting groove is matched with the outer diameter of the end of the spindle, so that when the locking piston moves toward the movable hole, the limiting groove can be fitted onto the end of the spindle that extends into the hole, thereby limiting its radial floating.

[0007] In one optional embodiment of this application, the radial mounting base includes: a mounting base body, one end of which is provided with the plurality of vertical mounting holes, and the other end of which is provided with an annular air groove; an air groove cover, fixed to the mounting base body to close the opening of the annular air groove, so that the two together form an annular gas channel; the air groove cover is provided with a first air inlet communicating with the annular gas channel; the annular gas channel is connected to each of the radial cylinders through an air passage in the mounting base body.

[0008] In one optional embodiment of this application, the end of the radial piston is provided with a ball bearing structure; the ball bearing structure includes: a ball bearing mounting seat, disposed at the end of the radial piston away from the radial cylinder; and a ball bearing, rotatably disposed in the ball bearing mounting seat and in contact with the bottom of the movable inner ring of the spherical bearing.

[0009] In one optional embodiment of this application, the limiting groove at the end of the locking piston includes a vertical section and a guide section that are connected to each other; the guide section is located at one end of the limiting groove near the main shaft, and its opening size gradually expands towards the main shaft to form a flared structure; the main shaft is provided with a tapered guide surface at the end corresponding to the locking piston, and the tapered guide surface is adapted to the guide section of the limiting groove; the inner diameter of the vertical section matches the outer diameter of the end of the main shaft, and when the locking piston moves to the locking position, the vertical section is sleeved on the end of the main shaft to limit its radial swing.

[0010] In one optional embodiment of this application, the movable hole on the radial mounting base has an inner edge with a chamfer at one end facing the spindle.

[0011] In one optional embodiment of this application, the radial limiting block includes a connecting part and a limiting part coaxially arranged with different diameters, wherein the diameter of the connecting part is larger than the diameter of the limiting part; the connecting part is used for fixed connection with the connecting flange of the robot arm, and the limiting hole is disposed through the limiting part; the elastic element is sleeved on the piston rod of the axial cylinder, one end of the elastic element abuts against the end face of the limiting part, and the other end abuts against the end face of the axial mounting seat.

[0012] In one optional embodiment of this application, the axial constant force floating structure is further provided with a guiding mechanism; the guiding mechanism includes: at least one guide post, fixed on the radial limiting block and extending toward the axial cylinder; a guide hole cooperating with the guide post, provided on the end face of the axial mounting seat toward the radial limiting block; the guide post is slidably inserted into the guide hole.

[0013] In one optional embodiment of this application, the guide post includes a large-diameter section and a small-diameter section coaxially arranged. The small-diameter section is connected to the radial limiting block, and the large-diameter section is slidably inserted into the guide hole. A stop block is provided at the opening of the guide hole, and a through hole is provided on the stop block. The diameter of the through hole is larger than the diameter of the small-diameter section and smaller than the diameter of the large-diameter section.

[0014] In one optional embodiment of this application, the axial mounting base is provided with an axial gas passage and an axial mounting hole for mounting an axial cylinder; the axial gas passage is connected to the movable hole and the axial mounting hole respectively; a second air inlet is provided on the side wall of the axial mounting base, which is connected to the axial gas passage.

[0015] In summary, the beneficial effects of this utility model are:

[0016] This invention discloses a constant-force floating device for robots, comprising a housing and integrated axial constant-force floating structure, radial constant-force floating structure, and radial floating locking structure. The axial constant-force floating structure uses an axial cylinder to drive a piston, which, in conjunction with a radial limiting block and an elastic element, achieves axial constant-force compensation. The radial constant-force floating structure supports the main shaft via a joint bearing, and a radially arrayed array of radial cylinders abuts against the inner ring of the bearing, achieving radial omnidirectional oscillation and constant-force output. The radial floating locking structure uses a locking cylinder to drive a piston with a limiting groove to fit over the end of the main shaft, achieving radial rigid locking. This invention integrates active constant-force floating functions in both axial and radial directions and can quickly switch to a rigid locking state, effectively improving the robot's adaptability, process stability, and operational efficiency in complex force-controlled operations such as grinding and deburring. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the constant force floating device for robots according to this utility model;

[0019] Figure 2 This is an exploded view of the constant force floating device for robots in this utility model;

[0020] Figure 3 This is a cross-sectional view of the constant force floating device for robots in this utility model;

[0021] Figure 4 This is a cross-sectional view of the radial floating locking structure in the locked state in this utility model;

[0022] Wherein: 100, housing; 110, axial constant force floating structure; 111, axial mounting seat; 1111, movable hole; 1112, second air inlet; 112, axial cylinder; 113, axial piston; 114, radial limiting block; 1141, limiting hole; 115, elastic element; 116, guide post; 120, radial constant force floating structure; 121, main shaft; 1211, tapered guide surface; 122, spherical bearing; 1221, fixed outer ring; 1222, movable inner ring; 123. Radial mounting base; 1231. Mounting base body; 12311. Vertical mounting hole; 12312. Annular air groove; 1232. Air groove cover; 12321. First air inlet; 124. Radial cylinder; 125. Radial piston; 126. Ball bearing; 130. Radial floating locking structure; 131. Locking cylinder; 132. Locking piston; 1321. Limiting groove; 1322. Guide section; 140. Robot arm connecting flange; 150. Actuating tool connecting flange. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

[0024] Please see Figure 1 , Figure 2 , Figure 3 and Figure 4In one embodiment of this utility model, a constant force floating device for a robot is disclosed, including an axial constant force floating structure 110, a radial constant force floating structure 120, a radial floating locking structure 130, and a housing 100. The axial constant force floating structure 110 includes: an axial cylinder 112 assembly, including an axial mounting seat 111 and an axial cylinder 112 fixedly installed in the axial mounting seat 111, the axial mounting seat 111 being fixed within the housing 100; an axial piston 113, disposed on the axial cylinder 112, capable of axial movement under its drive; and a radial limiting block 114, fixed within the housing 100, located at the end of the axial piston 113 away from the axial cylinder 112. A through-hole 1141 is provided on the limiting block 114, the diameter of which matches the diameter of the axial piston 113. The axial piston 113 is axially slidable within the limiting hole 1141. An elastic element 115 is provided between the radial limiting block 114 and the axial mounting seat 111. A robot arm connecting flange 140 is fixedly connected to the radial limiting block 114. The radial constant force floating structure 120 includes: a main shaft 121, a joint bearing 122, and a radial constant force cylinder assembly. The fixed outer ring 1221 of the joint bearing 122 is fixed to the housing 100, and its movable inner ring 1222 is fixedly connected to the main shaft 121, allowing the main shaft 121 to be omnidirectionally oscillating within the housing. Within 100; the axial mounting seat 111 has a movable hole 1111 at one end away from the axial cylinder 112, and one end of the main shaft 121 extends into the movable hole 1111. The diameter of the movable hole 1111 is larger than the outer diameter of the main shaft 121; the radial constant force cylinder assembly includes a radial mounting seat 123, a radial cylinder 124, and a radial piston 125; the radial mounting seat 123 is arranged around the main shaft 121 and fixedly connected to the housing 100, and has a plurality of vertical mounting holes 12311 arranged circumferentially on its end face facing the spherical bearing 122; the radial cylinder 124 is located in the vertical mounting holes 12311 and can drive the radial piston 125 to move axially, so that the end of the radial piston 125 is in contact with the spherical bearing. The bottom of the movable inner ring 1222 of 122 abuts against each other; the radial floating locking structure 130 includes: a locking cylinder 131, which is fixedly mounted on the axial mounting seat 111 and communicates with the movable hole 1111; a locking piston 132, which is slidably disposed in the movable hole 1111 and driven by the locking cylinder 131 to move axially along the movable hole 1111; the end of the locking piston 132 is provided with a limiting groove 1321, the inner diameter of the limiting groove 1321 matches the outer diameter of the end of the main shaft 121, so that when the locking piston 132 moves toward the opening of the movable hole 1111, the limiting groove 1321 can be fitted onto the end of the main shaft 121 that extends into the hole, thereby limiting its radial floating.

[0025] In the specific implementation process, in the initial state, the axial cylinder 112 in the axial constant force floating structure 110 pushes the axial piston 113 forward through a preset air pressure. The axial piston 113 transmits the thrust to the entire radial floating structure and the end-effector connecting flange 150, giving the entire device an initial forward constant force. When the tool installed at the end of the spindle 121 contacts the workpiece surface, if there is an axial deviation between the robot's feed displacement and the actual position of the workpiece, the tool will be subjected to a reverse force. This reverse force is transmitted to the axial piston 113 through the spindle 121 and the radial limiting block 114, overcoming the thrust of the cylinder and the elastic force of the elastic element 115, forcing the axial piston 113 to slide axially within the limiting hole 1141 of the radial limiting block 114. During this process, the internal pressure of the axial cylinder 112 is maintained constant through a closed-loop control system, thereby ensuring that the axial piston 113 continuously outputs a stable axial contact force, realizing active constant force floating compensation in the axial direction.

[0026] In its initial state, the radial constant force floating structure 120's radial cylinders 124 are driven by uniform air pressure to extend their radial pistons 125 forward, collectively abutting against the bottom of the movable inner ring 1222 of the spherical bearing 122, providing a centrally located radial preload force to the spindle 121. When the tool contacts the workpiece side radially or encounters contour fluctuations, the radial force is transmitted to the spindle 121, causing the spindle 121 to drive the movable inner ring 1222 of the spherical bearing 122 to oscillate slightly relative to the fixed outer ring 1221. The oscillation of the spindle 121 compresses one radial piston 125, causing it to retract, while the other radial piston 125 gains more space to extend. The system adjusts the pressure of each radial cylinder 124 in real time, ensuring that the resultant force exerted by all pistons on the movable inner ring 1222 is always equal in magnitude and opposite in direction to the radial force exerted on the workpiece. Through this closed-loop control, regardless of the swing angle of the spindle 121, the tool can always maintain a constant radial pressure on the side of the workpiece, realizing active constant force floating and adaptive centering in the radial direction.

[0027] When the robot needs to move quickly or perform non-contact operations, the radial floating locking structure 130 vents the locking cylinder 131, driving the locking piston 132 to move towards the orifice (i.e., towards the main shaft 121) within the movable hole 1111 of the axial mounting seat 111. The limiting groove 1321 (its guide section 1322) at the front end of the locking piston 132 first contacts the end of the main shaft 121, and automatically centers under the guidance of the tapered guide surface 1211, allowing the end of the main shaft 121 to smoothly slide into the vertical section of the limiting groove 1321. After the locking piston 132 has moved into position, the vertical section of its limiting groove 1321 tightly holds the end of the main shaft 121. Because the inner diameter of the vertical section precisely matches the outer diameter of the main shaft 121, any radial swing of the main shaft 121 is mechanically restricted, thereby achieving complete radial floating locking. The entire device becomes a rigid body, ensuring the positioning accuracy of the robot during high-speed movement.

[0028] For example, please refer to Figure 3 The radial mounting base 123 includes: a mounting base body 1231, one end of which is provided with the plurality of vertical mounting holes 12311, and the other end is provided with an annular air groove 12312; an air groove cover 1232, which is fixed to the mounting base body 1231 to close the opening of the annular air groove 12312, so that the two together form an annular gas channel; the air groove cover 1232 is provided with a first air inlet 12321 communicating with the annular gas channel; the annular gas channel is connected to each of the radial cylinders 124 through the air passage in the mounting base body 1231.

[0029] In the specific implementation process, an external air source is connected to the first air inlet 12321 through a pipeline, and compressed gas enters the annular gas channel formed by the air groove cover 1232 and the annular air groove 12312. Subsequently, the gas is evenly dispersed throughout the entire annular channel and is synchronously and parallelly delivered to the radial cylinder 124 at the bottom of each vertical mounting hole 12311 through multiple independent air passages connected to it and distributed inside the mounting body 1231.

[0030] For example, the radial piston 125 is provided with a ball structure at its end; the ball structure includes: a ball mounting seat, located at one end of the radial piston 125 away from the radial cylinder 124; and a ball 126, rotatably disposed in the ball mounting seat and in contact with the bottom of the movable inner ring 1222 of the spherical bearing 122.

[0031] Specifically, at the end of the radial piston 125, a cup-shaped ball bearing seat is provided, with a hemispherical or bowl-shaped recess machined inside. The ball 126 is partially embedded in this recess and is restrained within it by a retaining ring or a press-fitted flange structure, preventing it from falling out while still allowing for free rotation. This creates a low-friction rotating pair between the ball 126 and the ball bearing seat. This effectively reduces the motion resistance during radial floating, thereby eliminating motion hysteresis, improving the accuracy and sensitivity of constant force control, and significantly reducing component wear, thus extending the service life of the device.

[0032] For example, please refer to Figure 2 , Figure 3 and Figure 4 The limiting groove 1321 at the end of the locking piston 132 includes a vertical section and a guide section 1322 that are connected to each other. The guide section 1322 is located at the end of the limiting groove 1321 near the main shaft 121, and its opening size gradually expands towards the main shaft 121 to form a flared structure. The main shaft 121 is provided with a tapered guide surface 1211 corresponding to the end of the locking piston 132. The tapered guide surface 1211 is adapted to the guide section 1322 of the limiting groove 1321. The inner diameter of the vertical section matches the outer diameter of the end of the main shaft 121. When the locking piston 132 moves to the locking position, the vertical section is sleeved on the end of the main shaft 121 to limit its radial swing.

[0033] In this embodiment, when the main shaft 121 is in a floating state, its end is radially and angularly offset relative to the limiting groove 1321 of the locking piston 132. When the limiting groove 1321 approaches the main shaft 121, the trumpet-shaped guide section 1322 first contacts the tapered guide surface 1211 at the end of the main shaft 121. At the moment of contact, the tilted main shaft 121 abuts against the inclined surface of the guide section 1322. As the locking piston 132 continues to advance, the interaction force generated on the inclined surface forces the tilted main shaft 121 to produce a slight return motion, ultimately allowing the end of the main shaft 121 to smoothly slide into the precise vertical section of the limiting groove 1321. The guide section 1322 makes the locking action no longer require the main shaft 121 to be in a precise zero position, but can actively "capture" and "correct" the main shaft 121 at any floating angle, thereby improving the success rate and adaptability of locking, and ensuring that in complex work processes, the robot can quickly and accurately switch from any working posture to a rigid locking state.

[0034] For example, the movable hole 1111 on the radial mounting base 123 has a chamfer on its inner edge at the end facing the spindle 121. The chamfer provides additional clearance space for the spindle 121 when it swings, effectively preventing rigid scraping or interference between its outer surface and the sharp edge of the movable hole 1111, thereby protecting the components, reducing wear, and ensuring smooth floating motion.

[0035] For example, the radial limiting block 114 includes a connecting part and a limiting part that are coaxially arranged and have different diameters, and the diameter of the connecting part is larger than the diameter of the limiting part; the connecting part is used to be fixedly connected to the robot arm connecting flange 140, and the limiting hole 1141 is provided through the limiting part; the elastic element 115 is sleeved on the piston rod of the axial cylinder 112, one end of the elastic element 115 abuts against the end face of the limiting part, and the other end abuts against the end face of the axial mounting seat 111.

[0036] Specifically, when the axial piston 113 is driven, it pushes the radial limiting block 114 and the tool at the end of the spindle 121 against the workpiece. If the reaction force of the workpiece forces the piston to retract, the limiting part of the radial limiting block 114 will retract synchronously, compressing the elastic element 115 between it and the axial mounting seat 111. Conversely, when the force decreases or the robot retracts, the compressed elastic element 115 releases its stored energy, and its rebound force pushes the limiting part and the entire axial floating structure forward to reset. In this process, the elastic element 115 and the axial cylinder 112 together form a cooperative force system, providing axial reset force, absorbing shock, and enhancing system stability.

[0037] For example, the axial constant force floating structure 110 is further provided with a guide mechanism; the guide mechanism includes: at least one guide post 116, fixed on the radial limiting block 114 and extending toward the axial cylinder 112; a guide hole that cooperates with the guide post 116 is provided on the end face of the axial mounting seat 111 toward the radial limiting block 114; the guide post 116 is slidably inserted into the guide hole.

[0038] For example, the guide post 116 includes a large-diameter section and a small-diameter section coaxially arranged. The small-diameter section is connected to the radial limiting block 114, and the large-diameter section is slidably inserted into the guide hole. A stop is provided at the opening of the guide hole, and a through hole is provided on the stop. The diameter of the through hole is larger than the diameter of the small-diameter section and smaller than the diameter of the large-diameter section.

[0039] In this embodiment, when the axial piston 113 drives the radial limiting block 114 to move axially, the guide post 116 fixed on the radial limiting block 114 moves synchronously. Its large-diameter section slides precisely axially within the guide hole, providing stable radial support for the entire floating assembly, effectively preventing jamming or deflection caused by torque, and ensuring the straightness of the axial movement. When the device returns to its limit position, the small-diameter section of the guide post 116 can pass through the through hole on the stop, while the large-diameter section is reliably blocked by the stop, forming a mechanical limit and preventing the assembly from excessively retracting and disengaging.

[0040] For example, the axial mounting base 111 is provided with an axial gas passage and an axial mounting hole for mounting an axial cylinder 112; the axial gas passage is connected to the movable hole 1111 and the axial mounting hole respectively; the side wall of the axial mounting base 111 is provided with a second air inlet 1112 that is connected to the axial gas passage.

[0041] Specifically, when an external air source enters the axial gas channel through the second air inlet 1112, the compressed gas is divided into two paths: First, the gas enters directly through the axial gas channel to the rear end of the connected movable hole 1111, acting on the bottom of the locking piston 132 to provide power to the locking cylinder 131, driving the locking piston 132 to perform axial movement and achieve locking and unlocking functions. Second, the gas enters the rear chamber of the axial cylinder 112 through the connection between the axial gas channel and the axial mounting hole, providing power to the axial cylinder 112 to drive the axial piston 113 to perform axial constant force floating. Simultaneously, another independent air source supplies air to the radial constant force cylinder assembly through the first air inlet 12321. Thus, the axial cylinder 112, radial cylinder 124, and locking cylinder 131 of the floating device all obtain independent or parallel air sources, completing the entire air supply process.

[0042] In summary, the constant force floating device for robots in this embodiment includes a housing 100 and an axial constant force floating structure 110, a radial constant force floating structure 120, and a radial floating locking structure 130 integrated therein. The axial constant force floating structure 110 drives a piston via an axial cylinder 112, cooperating with a radial limiting block 114 and an elastic element 115 to achieve axial constant force compensation. The radial constant force floating structure 120 supports the main shaft 121 via a joint bearing 122, and a radial array of radial cylinders 124 abuts against the inner ring of the bearing, achieving radial omnidirectional oscillation and constant force output. The radial floating locking structure 130 drives a piston with a limiting groove 1321 via a locking cylinder 131 to fit over the end of the main shaft 121, achieving radial rigid locking. This invention integrates active constant force floating functions in both axial and radial directions and can quickly switch to a rigid locking state, effectively improving the robot's adaptability, process stability, and operating efficiency in complex force-controlled operations such as grinding and deburring.

[0043] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other.

[0044] It should be noted that this utility model uses a constant force floating device for robots as an example to introduce the specific structure and working principle of this utility model. However, the application of this embodiment is not limited to constant force floating devices for robots, and can also be applied to the production and use of other similar workpieces.

[0045] It should be understood that this invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of this invention is limited only by the appended claims.

[0046] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A constant-force floating device for robots, characterized in that: It includes an axial constant force floating structure (110), a radial constant force floating structure (120), a radial floating locking structure (130), and a housing (100). The axial constant force floating structure (110) includes: An axial cylinder assembly includes an axial mounting base (111) and an axial cylinder (112) fixedly mounted in the axial mounting base (111), wherein the axial mounting base (111) is fixed in the housing (100). An axial piston (113) is mounted on the axial cylinder (112) and can move axially under its drive; A radial limiting block (114) is fixed inside the housing (100) and located at the end of the axial piston (113) away from the axial cylinder (112). The radial limiting block (114) is provided with a through limiting hole (1141). The diameter of the limiting hole (1141) matches the diameter of the axial piston (113). The axial piston (113) can slide axially inside the limiting hole (1141). An elastic element (115) is provided between the radial limiting block (114) and the axial mounting seat (111). The robot arm connecting flange (140) is fixedly connected to the radial limiting block (114); The radial constant force floating structure (120) includes: a main shaft (121), a spherical bearing (122), and a radial constant force cylinder assembly; The fixed outer ring (1221) of the spherical bearing (122) is fixed to the housing (100), and its movable inner ring (1222) is fixedly connected to the main shaft (121), so that the main shaft (121) can be omnidirectionally oscillating inside the housing (100); the axial mounting seat (111) has a movable hole (1111) at one end away from the axial cylinder (112), and one end of the main shaft (121) extends into the movable hole (1111), the diameter of the movable hole (1111) is larger than the outer diameter of the main shaft (121); A radial constant force cylinder assembly includes a radial mounting base (123), a radial cylinder (124), and a radial piston (125). The radial mounting base (123) is arranged around the main shaft (121) and fixedly connected to the housing (100). A plurality of vertical mounting holes (12311) are arranged in a circular array on its end face facing the spherical bearing (122). The radial cylinder (124) is located in the vertical mounting holes (12311) and can drive the radial piston (125) to move axially, so that the end of the radial piston (125) abuts against the bottom of the movable inner ring (1222) of the spherical bearing (122). The radial floating locking structure (130) includes: A locking cylinder (131) is fixedly mounted on the axial mounting base (111) and communicates with the movable hole (1111); A locking piston (132) is slidably disposed in the movable hole (1111) and driven by the locking cylinder (131) to move axially along the movable hole (1111); the end of the locking piston (132) is provided with a limiting groove (1321), the inner diameter of the limiting groove (1321) matches the outer diameter of the end of the main shaft (121), so that when the locking piston (132) moves toward the opening of the movable hole (1111), the limiting groove (1321) can be sleeved on the end of the main shaft (121) that extends into the hole, thereby limiting its radial floating.

2. The constant force floating device for a robot according to claim 1, characterized in that, The radial mounting base (123) includes: The mounting base body (1231) has several vertical mounting holes (12311) at one end and an annular air groove (12312) at the other end. The air groove cover (1232) is fixed to the mounting body (1231) to close the opening of the annular air groove (12312), so that the two together form an annular gas channel; the air groove cover (1232) is provided with a first air inlet (12321) that communicates with the annular gas channel; the annular gas channel communicates with each of the radial cylinders (124) through the air passage in the mounting body (1231).

3. The constant force floating device for a robot according to claim 1, characterized in that, The radial piston (125) is provided with a ball bearing structure at its end; the ball bearing structure includes: A ball bearing mounting seat is located at the end of the radial piston (125) away from the radial cylinder (124); The ball (126) is rotatably disposed in the ball mounting seat and contacts the bottom of the movable inner ring (1222) of the spherical bearing (122).

4. The constant force floating device for a robot according to claim 1, characterized in that, The limiting groove (1321) at the end of the locking piston (132) includes a vertical section and a guide section (1322) that are connected. The guide section (1322) is located at one end of the limiting groove (1321) near the main shaft (121), and its opening size gradually increases towards the main shaft (121) to form a trumpet-shaped structure; The main shaft (121) is provided with a tapered guide surface (1211) at the end corresponding to the locking piston (132), and the tapered guide surface (1211) is adapted to the guide section (1322) of the limiting groove (1321); The inner diameter of the vertical section matches the outer diameter of the end of the main shaft (121). When the locking piston (132) moves to the locking position, the vertical section is sleeved on the end of the main shaft (121) to limit its radial swing.

5. The constant force floating device for a robot according to claim 1, characterized in that, The movable hole (1111) on the radial mounting base (123) has a chamfer on the inner edge of the end facing the main shaft (121).

6. The constant force floating device for a robot according to claim 1, characterized in that, The radial limiting block (114) includes a connecting part and a limiting part that are coaxially arranged and have different diameters. The diameter of the connecting part is larger than the diameter of the limiting part. The connecting part is used to be fixedly connected to the connecting flange (140) of the robot arm. The limiting hole (1141) is disposed through the limiting part. The elastic element (115) is sleeved on the piston rod of the axial cylinder (112). One end of the elastic element (115) abuts against the end face of the limiting part, and the other end abuts against the end face of the axial mounting seat (111).

7. The constant force floating device for a robot according to claim 1, characterized in that, The axial constant force floating structure (110) is also provided with a guiding mechanism; the guiding mechanism includes: At least one guide post (116) is fixed to the radial limiting block (114) and extends toward the axial cylinder (112); A guide hole that mates with the guide post (116) is provided on the end face of the axial mounting base (111) facing the radial limiting block (114); the guide post (116) is slidably inserted into the guide hole.

8. The constant force floating device for a robot according to claim 7, characterized in that, The guide post (116) includes a large-diameter section and a small-diameter section arranged coaxially. The small-diameter section is connected to the radial limiting block (114), and the large-diameter section is slidably inserted into the guide hole. The guide hole has a stop block at its opening, and the stop block has a through hole with a diameter greater than the diameter of the small diameter section and less than the diameter of the large diameter section.

9. The constant force floating device for a robot according to claim 1, characterized in that, The axial mounting base (111) is provided with an axial gas passage and an axial mounting hole for mounting an axial cylinder (112); the axial gas passage is connected to the movable hole (1111) and the axial mounting hole respectively; the side wall of the axial mounting base (111) is provided with a second air inlet (1112) connected to the axial gas passage.

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