Coolant following device and method of assembling same

Abstract

The application relates to a cooling liquid following device and an assembling method thereof. The device comprises a main shell, a water outlet column rotatably arranged in a mounting hole of the main shell, an O-shaped ring embedded in a sealing groove of the water outlet column, a threaded nozzle pipe connected with a threaded hole of the water outlet column and a copper nozzle, a rudder arranged in a rudder mounting position of the main shell and having an output end engaged with a gear hole of the water outlet column, a main shell cover fixed to the main shell, a filling sealant filled in an assembling area of the rudder and the main shell, and a controller assembly electrically connected with the rudder. The assembling method comprises the steps of sealing assembly of the water outlet column, nozzle glue coating and curing, rudder pre-debugging, engagement after the rudder pre-debugging, and filling sealing after full stroke rotation verification. The application realizes accurate following of a spraying angle through gear engagement transmission, and coordinates the rotation freedom and the sealing reliability through the space partition design protected by the O-shaped ring sealing and the filling sealant.

Description

Technical Field

[0001] This application relates to the field of machine tool cutting, and in particular to a coolant following device and its assembly method. Background Technology

[0002] In machine tool cutting, the degree to which the coolant spray direction matches the cutting area directly affects tool life and workpiece machining accuracy. When the coolant deviates from the cutting area, the cutting temperature rises, tool wear intensifies, and dimensional deviations occur on the workpiece surface due to thermal deformation. Therefore, the coolant spraying device needs to have the ability to dynamically adjust the spray angle to follow the tool cutting trajectory.

[0003] Existing machine tool coolant spraying devices mostly use fixed nozzles or manually adjustable nozzles. Fixed nozzles lock the spray angle during installation, and the direction cannot be changed during machining. They can only cover a fixed area, and the coolant coverage decreases as the tool moves along a complex trajectory. While manually adjustable nozzles allow operators to realign the spray direction during machining breaks, they cannot be adjusted in real time during cutting and rely on the operator's experience to estimate the angle, making it difficult to guarantee adjustment accuracy and repeatability.

[0004] Some improvement schemes attempt to introduce an electric drive mechanism to achieve automatic adjustment of the spray angle. However, in practical applications, they face a structural contradiction: when the drive mechanism and the water outlet channel coexist within the same housing, the rotational freedom required for drive transmission conflicts with the sealing requirements for coolant sealing. To provide rotational freedom, a clearance must be maintained between the water outlet column and the housing, which is precisely the channel through which coolant permeates into the housing. Increasing the number of sealing layers can suppress permeation, but each additional layer increases the frictional resistance during water outlet column rotation, reducing transmission accuracy due to the uncertainty of frictional torque. The meshing fit between the output end of the drive mechanism and the water outlet column is also more prone to misalignment due to assembly stress. Simultaneously, filling the housing with potting compound can protect the drive mechanism and cable connections from coolant corrosion, but the potting compound is fluid before curing. If it flows into the meshing area between the drive mechanism and the water outlet column, it will directly cause the transmission to jam. These contradictions are not isolated but coupled within the same limited space; that is, there is a trade-off between rotational transmission accuracy, sealing reliability, and assembly feasibility. Summary of the Invention

[0005] In order to achieve multi-layer sealing protection without sacrificing transmission accuracy and to prevent potting compound from entering the transmission area during assembly, this application provides a coolant following device and its assembly method.

[0006] Firstly, the coolant following device provided in this application adopts the following technical solution: A coolant following device, comprising: The main housing is provided with mounting holes and servo motor mounting positions; A water outlet column is rotatably disposed in the mounting hole. The outer wall of the water outlet column is provided with a sealing groove, the bottom of the water outlet column is provided with a gear hole, and the top of the water outlet column is provided with a threaded hole. An O-ring is embedded in the sealing groove to seal the gap between the water column and the wall of the mounting hole. A threaded nozzle tube, one end of which is screwed into the threaded hole, has a fixing adhesive coating on its outer wall; A copper nozzle is screwed and fixed to the other end of the threaded nozzle tube; A servo motor is installed in the servo motor mounting position, and the output end of the servo motor meshes with the gear hole to drive the water jet to rotate in the mounting hole; The main housing cover is fixedly connected to the main housing, and the main housing cover and the main housing together form a cavity for accommodating the servo motor; Encapsulating compound is applied to the assembly area between the servo and the main housing, covering the connection between the servo and the main housing; and A controller assembly, electrically connected to the servo motor, is used to send angle control signals to the servo motor.

[0007] By adopting the above technical solution, the water jet engages with the servo motor output end through the gear hole. When the servo motor rotates, it directly drives the water jet to rotate in the mounting hole, thereby changing the spray direction of the threaded nozzle tube and the copper nozzle, allowing the coolant spray direction to be adjusted to follow the cutting trajectory of the machine tool. An O-ring is embedded in the sealing groove on the outer wall of the water jet, forming a rotational seal between the water jet and the mounting hole wall, preventing coolant from seeping into the housing along the mating gap. Potting compound fills the assembly area between the servo motor and the main housing and covers the connection points, forming a cured protective layer on the outside of the gear meshing transmission area, isolating the servo motor and cable interface from the coolant splash environment. The main housing cover and the main housing enclose a sealed cavity, forming a two-stage protection from structural sealing to material filling, together with the potting compound. The controller assembly is electrically connected to the servo motor and sends angle control signals, providing drive commands for the dynamic adjustment of the spray angle. The above structure spatially partitions the rotational transmission path, sealing protection path, and potting protection area within the same main housing, enabling transmission accuracy, sealing reliability, and environmental protection to coexist harmoniously within a limited space.

[0008] Optionally, the O-ring is made of fluororubber, and the surface of the O-ring is coated with lubricating grease; the edges of the water outlet column are polished to eliminate sharp corners.

[0009] By adopting the above technical solutions, fluororubber O-rings possess oil resistance, high temperature resistance, and chemical corrosion resistance. They are not prone to aging and deformation under long-term contact with cutting coolant, maintaining durable sealing performance. The lubricating grease coating on the O-ring surface reduces the friction between the O-ring and the hole wall when the water jet is pushed into the mounting hole, preventing the O-ring from twisting or being crushed due to excessive shear force during assembly. After the edges of the water jet are ground and trimmed to eliminate sharp corners, the water jet will not scrape the O-ring surface with sharp edges during insertion into the mounting hole, avoiding scratches or cuts on the sealing surface. The combined effect of lubrication and edge trimming on the stress state of the O-ring during assembly reduces the risk of seal failure due to assembly operations.

[0010] Optionally, the meshing clearance between the output end of the servo and the gear hole is no greater than 0.1 mm; the two ends of the servo are free of parts that interfere with the assembly of the main housing; and double-sided tape is attached to the top of the servo.

[0011] By adopting the above technical solution, the meshing clearance is controlled within a range of no more than 0.1mm, reducing the amount of backlash between the servo motor output end and the gear hole. This allows the servo motor's angle command to be transmitted to the water jet with minimal transmission error, improving the positioning accuracy and repeatability of the spray angle. After removing the parts at both ends of the servo motor that would interfere with the main housing during assembly, the servo motor can be smoothly installed in the servo motor mounting position without generating compressive stress on the inner wall of the housing, avoiding housing deformation or damage to the servo motor housing due to forced assembly. The double-sided adhesive attached to the top of the servo motor forms an elastic adhesive layer between the servo motor and the housing, suppressing the micro-displacement of the servo motor during operation vibration and maintaining the stability of the meshing alignment.

[0012] Optionally, it also includes a cable connection structure, the cable connection structure comprising: A shielding wire, wherein the shielding wire is soldered to the servo motor wires of the servo motor according to a preset wiring sequence; and Heat shrink tubing is fitted onto the weld joint between the servo cable and the shielding cable.

[0013] By adopting the above technical solution, the shielded wire and the servo wire are welded together according to a preset wiring sequence, ensuring that the correspondence between each signal channel is fixed and traceable, thus avoiding control signal disorder caused by incorrect wiring sequence. The metal braided layer of the shielded wire shields against external electromagnetic interference, reducing interference from high-power equipment such as machine tool motors and frequency converters on the angle control signal. Heat shrink tubing is applied to the weld joint and, after being heated and shrunk, adheres tightly to the cable surface, forming an insulating coating layer on the outside of the weld joint, preventing short circuits or breakages in environments with coolant splashes and mechanical vibration.

[0014] Optionally, the controller component includes: Servo plug-in board and servo adapter board, wherein the servo plug-in board and the servo adapter board are connected by welding with a single core wire, and the corner positions correspond one to one; Cut the foam and attach it around the indicator light on the servo motor plug-in board; Battery housing for accommodating the servo drive insert board and the servo drive adapter board; and The controller potting compound is filled inside the battery box housing and covers the servo motor plug-in board and the servo motor adapter board. The filling thickness of the controller potting compound is not less than 5mm.

[0015] By adopting the above technical solution, the servo motor plug-in board and the servo motor adapter board are welded with single-core wires and their corner positions correspond one-to-one, thus fixing the signal transmission path between the two circuit boards and reducing the risk of signal interruption due to poor contact or loose plugging and unplugging. Cut foam is placed around the indicator light to form a local seal between the battery box housing and the plug-in board surface, preventing the potting compound from covering the light-emitting surface of the indicator light during the potting process. The controller potting compound is filled into the battery box housing with a thickness of not less than 5mm and covers the two circuit boards, so that the circuit boards and their solder joints are completely wrapped by the cured compound, isolating them from external moisture, dust and coolant penetration, while applying a uniform fixing force to the circuit boards to suppress fatigue fracture of component solder joints under vibration.

[0016] Optionally, the controller component further includes: The battery box rear cover fits and seals with the battery box housing; A fixing hook and a fixing plate are installed on the rear cover of the battery box to fix the controller assembly to the machine tool.

[0017] By adopting the above technical solution, the battery box rear cover and battery box housing are fitted together to form a physical shell protection on the outer layer of the controller potting compound, making the controller assembly an independent sealed module. Fixing hooks and fixing plates are installed on the battery box rear cover, providing an installation interface for fixing the controller assembly to the machine tool body, allowing the installation position and orientation of the controller assembly to be adapted and adjusted according to the spatial layout of different machine tool models.

[0018] Secondly, the assembly method of the coolant following device provided in this application adopts the following technical solution: A method for assembling a coolant follower device, for assembling the coolant follower device as described above, includes the following steps: S1. Inspect the edge of the water column. If there are sharp corners or burrs on the edge of the water column, grind and trim the sharp corners or burrs. Apply lubricating grease to the surface of the O-ring. Embed the O-ring with lubricating grease into the sealing groove of the water column. Push the water column into the mounting hole of the main housing until the thread of the threaded nozzle tube is fully exposed. Verify that the O-ring is not crushed or damaged. S2. Apply the fixing adhesive to the outer wall of the threaded nozzle tube, screw the copper nozzle to the end of the threaded nozzle tube, adjust the spray angle of the copper nozzle to the preset position, and let it stand until the fixing adhesive cures. S3. The servo motor is pre-driven to a set angle by the controller assembly. The servo motor is installed from the back of the main housing into the servo motor mounting position and the output end of the servo motor is engaged with the gear hole of the water outlet column. The water outlet column is rotated in its full stroke to verify that the rotation is flexible and without jamming. In response to the successful full stroke rotation verification, the servo motor wire and the shielding wire of the servo motor are welded in a preset wire sequence and heat shrink tubing is sleeved at the weld. The potting compound is injected into the assembly area between the servo motor and the main housing. The main housing cover is then fixed to the main housing. S4. Assemble the controller assembly and electrically connect the controller assembly to the servo motor.

[0019] By adopting the above technical solution, the assembly method is performed sequentially in the order of water column assembly, nozzle assembly, servo motor assembly, and controller assembly. Each stage has a pre-verification relationship; that is, S2 can only proceed after verifying in S1 that the O-ring is free from compression damage, and welding and potting operations can only be performed after verifying full-stroke rotation in S3. This process arrangement places irreversible operations after reversible verification, ensuring that each irreversible operation is guaranteed by a pre-existing reversible check. The inspection and grinding of the water column edge, as a pre-processing step for O-ring installation, eliminates the risk of O-ring assembly damage due to edge burrs. Before being installed in the main housing, the servo motor is pre-driven to a set angle by the controller, ensuring that the servo motor output end is aligned with the gear hole at a known angle, reducing the difficulty of meshing alignment.

[0020] Optionally, step S3 includes the following sub-steps: S31. Connect the servo motor to the controller assembly via a test cable, and drive the servo motor to rotate to a set angle via the controller assembly; S32. Install the servo motor from the back of the main housing into the servo motor mounting position, and adjust the position of the servo motor so that the output end of the servo motor meshes with the gear hole of the water outlet column; S33. Manually rotate the water column to confirm that the water column rotates flexibly throughout its entire stroke range without jamming or deviation; S34. In response to the successful verification of S33, the servo motor wire and the shield wire of the servo motor are welded in a preset sequence, and heat shrink tubing is applied to the weld and heated to shrink it. S35. Inject the potting compound into the assembly area between the servo and the main housing to fix the main housing cover to the main housing; After S31 and before S32, the following steps are also included: removing the parts at both ends of the servo that interfere with the assembly of the main housing, and attaching double-sided tape to the top of the servo.

[0021] By adopting the above technical solution, S3 is subdivided into five sub-steps: pre-adjustment, installation and engagement, full-stroke verification, welding, and potting, plus an additional adaptation and adjustment step. This ensures that each operational node in the servo assembly process has clear execution conditions and verification standards. In S31, the servo is connected to the controller assembly via an adjustment cable and rotated to the set angle, separating angle calibration from the assembly process in advance. This allows the assembly process to focus only on physical alignment without simultaneously adjusting the angle. The manual full-stroke rotation verification in S33 is performed before potting, providing operators with a reworkable inspection window. If the verification fails, the servo is not yet fixed by the potting compound and can still be removed and re-aligned. The additional step of removing assembly interference parts and applying double-sided tape is performed after S31 and before S32, ensuring that the servo meets the installation conditions in terms of both physical shape and installation stability before the installation operation.

[0022] Optionally, after the verification in S33 is passed and before S34, the following steps are also included: Power on the servo motor and drive it to rotate back and forth within a set angle range to confirm that the water jet follows the servo motor's rotation without any abnormal noise.

[0023] By adopting the above technical solution, a verification step of servo motor reciprocating rotation with power is added after the manual rotation verification, expanding the verification scope from the static meshing state to the dynamic driving state. Manual rotation verification can only detect the smoothness of the water column's rotation under no-load conditions, while the servo motor reciprocating rotation verification detects the following performance of gear meshing and abnormal noises under the actual output torque of the servo motor. This covers dynamic transmission defects that manual verification cannot detect, such as tooth surface slippage within a specific angle range or periodic jamming caused by uneven meshing pitch. This verification step occurs before welding and potting operations, allowing for rework correction of meshing defects discovered during dynamic verification.

[0024] Optionally, in S3, after injecting the potting compound and fixing the main housing cover to the main housing, the assembled component is flipped so that the gear hole of the water outlet column faces upward, and the flipped position is maintained until the potting compound is cured; in S4, assembling the controller assembly includes injecting controller potting compound into the controller assembly, and the injection of controller potting compound is performed independently of the injection of potting compound in S3.

[0025] By adopting the above technical solution, after the potting compound is injected and the main housing cover is closed, the component is flipped so that the gear hole faces upward. Gravity causes the potting compound to settle away from the gear meshing surface during the curing process, preventing it from seeping into the meshing area between the gear hole and the servo output end before curing due to its own fluidity. If the potting compound enters the meshing area and cures, it will directly cause the water column to stop rotating, causing the device to lose its angle adjustment function, and it cannot be disassembled and reworked after potting. Therefore, the flipping attitude control physically blocks the path of the potting compound flowing into the meshing area. The potting compound for the controller and the potting compound for the servo area inside the controller component are potted independently, so that the operation of the two potting areas does not affect each other. When defects such as air bubbles or insufficient coverage occur in the potting of one area, only that area needs to be reworked, without affecting the potting of the other area that has already been completed. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the rotating water outlet assembly of the coolant following device provided in the embodiments of this application.

[0027] Figure 2 This is a schematic diagram of the servo drive assembly of the coolant following device provided in an embodiment of this application.

[0028] Figure 3 A schematic diagram of the controller assembly structure of the coolant following device provided in the embodiments of this application.

[0029] Explanation of reference numerals in the attached figures: 1. O-ring; 2. Water jet; 3. Copper nozzle; 4. Threaded nozzle tube; 5. Main housing; 6. Transmission engagement structure; 7. Servo; 8. Hex socket head cap screw; 9. Main housing cover; 10. Fixing hook; 11. Fixing plate; 12. Battery box rear cover; 13. Servo insert board; 14. Servo adapter board; 15. Battery box housing; 16. Cutting foam. Detailed Implementation

[0030] The present application will be further described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the application and are not intended to limit the scope of the application.

[0031] This application discloses a coolant following device and its assembly method, which is applicable to cutting and cooling scenarios of various machine tools such as CNC milling machines, CNC lathes, and machining centers.

[0032] The coolant follower device includes a main housing 5, a water outlet column 2, an O-ring 1, a threaded nozzle tube 4, a copper nozzle 3, a servo motor 7, a main housing cover 9, potting compound, and a controller assembly. The main housing 5 serves as the supporting base of the device. It has mounting holes and a mounting position for the servo motor 7. The mounting holes extend along the thickness of the main housing 5, and the mounting position for the servo motor 7 is located on one side of the back of the main housing 5 and is spatially adjacent to the mounting holes. The water outlet column 2 is a hollow columnar component that can be rotatably inserted into the mounting holes. The outer wall of the water outlet column 2 has an annular sealing groove, a non-circular gear hole at the bottom, and a threaded hole with internal threads at the top. The gear hole serves as the interface for transmitting torque between the output end of the servo motor 7 and the water outlet column 2. The sealing groove is a positioning structure for embedding the O-ring 1. After the O-ring 1 is embedded in the sealing groove, it is compressed in the radial direction, forming an elastic surface seal between the outer wall of the water outlet column 2 and the wall of the mounting hole. The fixing adhesive is an adhesive applied to the outer wall of the threaded nozzle tube 4. After curing, it serves both to prevent thread loosening and to seal the liquid.

[0033] There are two physical paths inside the device. The coolant flow path is as follows: the coolant enters the inner cavity of the water outlet column 2 from the outside of the main housing 5 through the mounting hole, flows upward along the inner cavity of the water outlet column 2, and reaches the outlet of the copper nozzle 3 through the inner hole of the threaded nozzle tube 4. The torque transmission path is as follows: the controller assembly generates an angle control signal and sends it to the servo motor 7. The output end of the servo motor 7 rotates, and through meshing with the gear hole, it transmits torque to the water outlet column 2. The water outlet column 2 rotates in the mounting hole, causing the threaded nozzle tube 4 and the copper nozzle 3 to change the spray direction.

[0034] Taking a three-axis CNC milling machine as an example, the workpiece is fixed on the worktable, and the spindle, equipped with a milling cutter, feeds along the X-axis to perform planar milling. A coolant follower device is installed on the side of the spindle box, and the spray angle is adjusted within ±30° to follow the tool displacement, ensuring that the coolant jet continuously covers the contact area between the milling cutter and the workpiece. Subsequent numerical examples in each section will be based on this scenario.

[0035] Existing fixed nozzles lock the spray direction during installation and cannot be changed during machining. As the tool moves along the feed direction, the offset between the coolant landing point and the cutting area increases with the tool stroke. This device dynamically adjusts the spray direction by driving the water column 2 to rotate via a servo motor 7, ensuring that the coolant landing point always follows the cutting area. When accommodating both the rotary transmission mechanism and the coolant channel within the same housing, there is a conflict between rotational freedom and sealing: to allow the water column 2 to rotate, a clearance must be maintained between the water column 2 and the mounting hole, and this clearance also constitutes a coolant penetration path. This device achieves rotational sealing by embedding an O-ring 1 into a sealing groove, forms a cured protective layer on the outside of the transmission area using potting compound, and encloses the cavity with the main housing cover 9. This spatially partitions the rotary transmission, sealing protection, and potting protection, coordinating their coexistence within the limited housing space.

[0036] The water outlet column 2 is a cylinder with a hollow inner cavity. Its outer diameter matches the inner diameter of the mounting hole in the main housing 5, and an annular sealing groove is formed on its outer wall. The sealing groove is located in the middle of the outer wall of the water outlet column 2, and its width and depth are adapted to the cross-sectional diameter of the O-ring 1, so that the O-ring 1 protrudes slightly above the groove opening in its natural state after being inserted. A gear hole is formed at the bottom of the water outlet column 2, i.e., the end facing the inside of the main housing 5. The cross-section of the gear hole is non-circular, matching the cross-sectional shape of the output end of the servo motor 7, and the two can transmit torque after meshing. A threaded hole is formed at the top of the water outlet column 2, i.e., the end facing the outside of the main housing 5, for screwing in the threaded nozzle tube 4.

[0037] After the water jet 2 is inserted into the mounting hole, the O-ring 1 is compressed radially under the constraint of the mounting hole wall, forming a continuous annular surface seal between the outer wall of the water jet 2 and the mounting hole wall. When the water jet 2 rotates, sliding friction occurs between the outer surface of the O-ring 1 and the mounting hole wall, while the inner surface of the O-ring 1 maintains static contact with the bottom of the sealing groove. The compression ratio of the O-ring 1 cross-section affects two parameters: sealing effect and frictional torque. A higher compression ratio results in a wider sealing surface contact width and a better sealing effect, but also increases the frictional torque. When the water jet 2 rotates, the servo motor 7 needs to output a larger torque to overcome the frictional resistance. The groove depth of the sealing groove is designed to minimize the compression amount while meeting the minimum compression ratio required for sealing, keeping the frictional torque within the driveable range of the servo motor 7's rated output torque.

[0038] The rotation angle range of the water jet 2 is determined by the output angle range of the servo motor 7 and the gear meshing transmission ratio. Taking the output angle range of the servo motor 7 as 0° to 180° as an example, when the gear meshing is a 1:1 direct drive transmission, the rotation angle range of the water jet 2 is also 0° to 180°. When the water jet 2 rotates to its limit angle, the cumulative rotation angle of the O-ring 1 reaches its maximum value. However, since the inner surface of the O-ring 1 remains statically attached to the bottom of the sealing groove, the O-ring 1 itself does not undergo axial torsion; only the friction between the outer surface and the hole wall generates circumferential shear force. When the rotation angle does not exceed 180°, the circumferential shear stress on the cross-section of the O-ring 1 is within the elastic deformation range and will not cause the O-ring 1 to fail torsion.

[0039] The threaded nozzle tube 4 is a straight tube with M6 external threads at both ends, with a tube length of 50mm and an internal coolant flow channel. One end of the threaded nozzle tube 4 is screwed into the threaded hole at the top of the water column 2, forming a threaded connection. The outer wall of the threaded nozzle tube 4 is coated with a fixing adhesive, which is an anaerobic or instant-drying adhesive. It cures in the closed anaerobic environment of the threaded mating surface to form an adhesive film. The adhesive film fills the micro-gap between the thread teeth and generates shear strength to bond the internal and external threads together. The cured adhesive film performs two functions: first, preventing thread loosening, i.e., preventing the threaded nozzle tube 4 from rotating and loosening relative to the water column 2 under machine tool vibration; second, sealing the liquid, i.e., preventing coolant from seeping outward along the spiral gap of the threaded mating surface. If the fixing adhesive is not applied, the continuous vibration during machine tool processing may cause the threaded connection to gradually loosen. After loosening, the thread gap increases, leading to coolant leakage. At the same time, the axis of the threaded nozzle tube 4 will be misaligned with the axis of the water column 2, affecting the accuracy of the spray direction.

[0040] The copper nozzle 3 has an M6 internal thread and is screwed and fixed to the other end of the threaded nozzle tube 4, i.e., the end facing the cutting area. The coolant flows from the inner cavity of the water column 2 through the inner hole of the threaded nozzle tube 4 to the outlet of the copper nozzle 3 and is ejected. The outlet shape and internal flow channel structure of the copper nozzle 3 determine the diffusion angle and range of the coolant jet.

[0041] Following the aforementioned baseline scenario, the threaded nozzle tube 4 is 50mm long, ensuring that the outlet of the copper nozzle 3 is approximately 50mm from the end face of the water column 2, thus extending the copper nozzle 3 closer to the cutting area. On a three-axis CNC milling machine, the contact area between the milling cutter and the workpiece is typically 80mm to 150mm from the coolant follower mounting point. The 50mm length of the threaded nozzle tube 4 shortens the air path between the nozzle outlet and the cutting area to within 30mm to 100mm, which helps reduce jet attenuation and dispersion in the air.

[0042] Servo motor 7 is a miniature servo motor, housed in a servo motor mounting position on the back of the main housing 5. The mounting position is a recessed structure on the back of the main housing 5, the inner contour of which matches the outer contour of the servo motor 7 housing. After the servo motor 7 is inserted into the mounting position from the back of the main housing 5, its output end faces inwards towards the main housing 5, axially aligned with the gear hole at the bottom of the water jet 2. Once the output end of the servo motor 7 is inserted into the gear hole, torque transmission is achieved through the mating of their non-circular cross sections. When the servo motor 7 rotates, it drives the water jet 2 to rotate synchronously within the mounting hole.

[0043] The main housing cover 9 is fixedly connected to the main housing 5 from the back, forming a closed cavity with the main housing 5, within which the servo motor 7 is housed. The main housing cover 9 is secured with four M2×6 socket head cap screws 8, with a tightening torque of 0.8 N·m. After the main housing cover 9 is closed, a housing-level physical isolation is formed between the servo motor 7 and the external environment, preventing coolant splashes and cutting dust from directly contacting the surface of the servo motor 7.

[0044] The potting compound is filled in the gap between the servo motor 7 and the inner wall of the main housing 5. After curing, it forms a solid gel filling layer, covering the contact surface between the servo motor 7 housing and the inner wall of the main housing 5, the servo cable exit point, and the mating gap between the main housing cover 9 and the main housing 5. Although the mating surfaces of the main housing cover 9 and the main housing 5 are tightened with screws, there is still a micron-level surface gap between them. Under pressure impact or capillary effect, coolant may penetrate into the cavity along this surface gap. The potting compound flows into the surface gap in its liquid state and fills it after curing, adding a material-level seal on top of the housing enclosure. The structural enclosure of the main housing cover 9 and the main housing 5 constitutes the first level of protection, while the material filling of the potting compound constitutes the second level of protection. The two levels of protection are complementary in mechanism.

[0045] The potting compound must be applied only to the assembly area between the servo motor 7 and the main housing 5, and must not enter the meshing surface between the gear hole and the output end of the servo motor 7. The meshing surface is the working interface for torque transmission, and a gap must be maintained between the gear teeth to allow relative rotation. If the potting compound seeps into the meshing surface and cures, the gear teeth will be bonded together by the compound, and the water jet 2 will not be able to rotate.

[0046] The controller assembly is a physically separate module from the main housing 5, and is electrically connected to the servo motor 7 via a cable. The controller assembly integrates a signal generation circuit, which is responsible for receiving external commands and generating corresponding angle control signals. These angle control signals are transmitted to the servo motor 7 via a cable. After receiving the signal, the servo motor 7 rotates its output terminal to the angle position specified by the signal.

[0047] The controller assembly is designed as an independent module, allowing it and the main housing 5 to be installed in different locations on the machine tool. The main housing 5 is installed near the spindle to shorten the distance between the nozzle and the cutting area, while the controller assembly is installed away from the coolant splash area to reduce the risk of corrosion to electronic components.

[0048] Optionally, the O-ring 1 is made of fluororubber and has a size of 10×1.5, i.e., an inner diameter of 10mm and a cross-sectional diameter of 1.5mm. The surface of the O-ring 1 is coated with lubricating grease. The edges of the water outlet column 2 are polished to eliminate sharp corners.

[0049] Fluororubber is a fluorinated elastomer with vinylidene fluoride as the main monomer. It exhibits resistance to mineral oils, synthetic cutting fluids, and high temperatures, maintaining its elasticity within a temperature range of -20°C to 200°C. Machine tool cutting coolants are typically water-based emulsions or synthetic cutting fluids, containing extreme pressure additives and corrosion inhibitors. These chemical components cause swelling and aging effects on general-purpose elastomers such as nitrile rubber. After prolonged immersion, the cross-section of nitrile rubber expands and softens, increasing its compression set and reducing the sealing surface adhesion. Fluororubber is inert to these chemical components, exhibiting minimal changes in cross-sectional dimensions and hardness under long-term immersion in cutting coolant, maintaining stable sealing performance throughout the device's design life. In other embodiments, the O-ring 1 can also be made of silicone rubber. Silicone rubber is suitable for conditions with wider temperature fluctuations but lower concentrations of oily media, such as coolant environments where water is the primary component. Furthermore, nitrile rubber is suitable for mineral oil-based cutting fluids and temperatures not exceeding 120°C. The materials of all these elastomers can be selected based on the specific type of coolant and operating temperature range.

[0050] The lubricating grease coated on the surface of O-ring 1 forms a liquid film between the outer surface of O-ring 1 and the wall of the mounting hole, transforming the dry friction between O-ring 1 and the hole wall into boundary lubrication friction. During the process of the water jet 2 being pushed into the mounting hole, O-ring 1 is gradually compressed radially, and the contact pressure between the outer surface of O-ring 1 and the hole wall increases from zero to the sealing working pressure. Without lubricating grease, the coefficient of friction between the outer surface of O-ring 1 and the hole wall is high during the increase of contact pressure, and O-ring 1 may be dragged axially by the pushing force, deviating from the correct position in the sealing groove or even falling out of the groove. After applying lubricating grease, the coefficient of friction decreases, the axial drag force on O-ring 1 during the pushing process is reduced, and it can be stably maintained within the sealing groove.

[0051] During the manufacturing process of the water outlet column 2, sharp corners or burrs from the machining process may remain at its edges. When the water outlet column 2 is pushed into the mounting hole, the sharp corners contact the chamfered area of ​​the mounting hole opening before the O-ring 1. These sharp corners do not damage the hole wall. However, as the water outlet column 2 continues to be pushed in until the O-ring 1 reaches its edge, the O-ring 1 adheres tightly to the outer wall of the water outlet column 2 under radial compression. The sharp corners create localized stress concentration on the surface of the O-ring 1, potentially forming cuts or scratches. These cuts disrupt the continuity of the O-ring 1 surface and become the starting point for penetration under coolant pressure. After grinding and finishing to eliminate the sharp corners, a smooth transition surface is formed at the edge, and the contact stress on the surface of the O-ring 1 is evenly distributed, preventing localized stress concentration.

[0052] Optionally, the meshing clearance between the output end of the servo motor 7 and the gear hole is no greater than 0.1mm. The ends of the servo motor 7 that would interfere with the assembly of the main housing 5 are removed. Double-sided adhesive tape is affixed to the top of the servo motor 7.

[0053] The meshing clearance is the maximum clearance between the output end section of servo motor 7 and the gear bore section in the mating direction. When the output end of servo motor 7 rotates, it must first consume the freewheeling angle corresponding to the meshing clearance before transmitting torque to the water jet 2 through tooth surface contact. This freewheeling angle is called the return angle. The existence of the return angle causes a deviation between the actual output angle of servo motor 7 and the actual rotation angle of water jet 2. Taking the effective meshing diameter of the gear bore as 8mm, the return angle corresponding to a meshing clearance of 0.1mm in the tangential direction of the tooth surface is approximately... With a nozzle tube length of 50mm and a nozzle outlet distance of 100mm from the cutting area, a 1.4° angular deviation causes a lateral offset of approximately 2.4mm in the coolant drop point. This offset is less than the cutting width of the milling cutter and has limited impact on the coolant coverage of the cutting area. If the meshing clearance increases to 0.3mm and the return angle increases to approximately 4.3°, the corresponding drop point offset increases to approximately 7.5mm, which may cause the coolant jet to deviate from the effective coverage range of the cutting area under finishing conditions.

[0054] The housing of servo motor 7 is an injection-molded part. The parting lines at both ends of the housing typically contain flash or lugs. The outer envelope of these protruding parts may exceed the inner contour of the servo motor 7 mounting position on the main housing 5. If the interfering parts are not removed and servo motor 7 is forcibly pressed into the mounting position, compressive stress will be generated between the protruding parts and the inner wall of the mounting position, potentially causing localized deformation of the inner wall. This deformation, transmitted to adjacent mounting hole areas, will affect the smooth rotation of the water jet 2. After removing the interfering parts, a uniform fit clearance is maintained between the outer contour of the servo motor 7 housing and the inner contour of the mounting position, allowing servo motor 7 to smoothly enter the mounting position.

[0055] The double-sided adhesive tape affixed to the top of the servo motor 7 is a foam-based double-sided pressure-sensitive adhesive tape. After the servo motor 7 is placed in the mounting position, the double-sided adhesive tape is located between the top surface of the servo motor 7 and the inner wall of the main housing 5, forming an elastic adhesive layer after compression. This elastic adhesive layer serves two purposes: first, it fills the irregular micro-gaps between the top surface of the servo motor 7 and the inner wall of the housing, increasing the contact area to disperse vibration loads; second, the pressure-sensitive adhesive layer of the double-sided adhesive generates adhesive force on both the top surface of the servo motor 7 and the inner wall of the housing, suppressing the micro-displacement of the servo motor 7 within the mounting position during servo motor 7 operation vibration, and maintaining the alignment between the output end of the servo motor 7 and the gear hole. In other embodiments, the auxiliary fixing method for the servo motor 7 can also adopt an elastic buckle structure, using the elastic arms of the buckle to clamp the housing of the servo motor 7 from both sides for positioning, or a silicone pad can be laid between the bottom surface of the servo motor 7 and the bottom surface of the mounting position to provide vibration damping support. All of the above auxiliary fixing methods can be selected according to the specific installation space and vibration conditions.

[0056] Optionally, the coolant follower device also includes a cable connection structure, which includes a shielded wire and heat shrink tubing. The shielded wire is soldered to the servo wire of the servo motor 7 according to a preset wiring sequence. The heat shrink tubing is fitted onto the solder joint between the servo wire and the shielded wire.

[0057] The servo cable is a multi-core flexible conductor integrated into servo motor 7, typically consisting of a positive power wire, a negative power wire, and a signal wire. The shielded cable is a multi-core signal cable with an outer metal braided layer. The metal braided layer shields against external electromagnetic fields, reducing the amplitude of electromagnetic interference signals coupled to the internal conductors. In the machine tool operating environment, high-frequency electromagnetic radiation is generated by powerful electrical equipment such as spindle motors, feed servo motors, and frequency converters during operation. If the angle control signal picks up this interference during transmission, servo motor 7 may experience angle jitter or malfunction, causing the jet direction to deviate from the target position. After soldering the servo cable to the shielded cable, the angle control signal is transmitted from the controller component through the shielded cable to the soldering point, and then through a short distance via the servo cable to reach servo motor 7. The majority of the signal line length is protected by the shielding of the metal braided layer.

[0058] The welding sequence is fixed according to a preset rule, that is, the colors or numbers of the positive power wire, negative power wire, and signal wire correspond one-to-one with the core wires inside the shielding wire. Welding according to the fixed sequence ensures that the correspondence of each signal channel can be traced and verified during production and maintenance, avoiding problems such as the servo motor 7 being burned out due to incorrect wiring sequence or short circuits caused by signal wires being connected to the power channel.

[0059] After welding, heat shrink tubing is fitted over the weld joint. Heating with a hot air gun causes the tubing to shrink radially, forming a continuous insulating layer that adheres tightly to the weld point and the cable sheath. The heat shrink tubing provides two functions: electrical insulation, isolating the exposed weld point from the external conductor and preventing short circuits caused by coolant splashes; and mechanical protection, applying radial pressure to the weld point after shrinkage, enhancing its fatigue resistance under vibration and cable tension. In other embodiments, cable connections can also be achieved using plug-in waterproof connectors. The male connector is installed at the end of the servo cable, and the female connector is installed at the end of the shielded cable. After insertion, a sealing ring and locking structure simultaneously achieve electrical connection and waterproof / dustproof protection. All of the above cable connection methods can be selected based on the specific installation space and ease of maintenance.

[0060] Optionally, the controller assembly includes a servo plug-in board 13 and a servo adapter board 14, cutting foam 16, a battery box housing 15, and controller potting compound.

[0061] The servo module insert board 13 and the servo adapter board 14 are two printed circuit boards, respectively carrying the angle control signal generation circuit and the external connection interface circuit. The two circuit boards are connected by soldering single-core wires. One end of each single-core wire is soldered to a pad on the servo module insert board 13, and the other end is soldered to the corresponding pad on the servo adapter board 14. The one-to-one correspondence of the angles means that the signal channel attributes of each solder point are strictly matched on the two boards, and there is no misalignment connection. The two circuit boards are stacked vertically or arranged side by side inside the battery box housing 15, and the length of the single-core wire matches the spacing between the two boards.

[0062] The cut foam 16 is a closed-cell foam material cut to fit the outer contour of the indicator light on the servo motor insert plate 13, and is attached around the indicator light to form an annular dam. The indicator light on the servo motor insert plate 13 is used to indicate the working status of the controller, such as power-on indication or signal transmission indication. During the potting compound injection process, the liquid potting compound flows from high to low under its own gravity. If no dam is set, the potting compound will cover the light-emitting surface of the indicator light, forming an opaque shielding layer after curing, making the indicator light invisible from the outside. The annular dam formed by the cut foam 16 around the indicator light is higher than the preset liquid level of the potting compound. The liquid potting compound is blocked outside the dam and cannot flow over the dam into the indicator light area. After the potting compound cures, the light-emitting surface of the indicator light remains exposed.

[0063] The battery box housing 15 is a rectangular box molded by injection molding, with the opening facing upwards, used to accommodate the two circuit boards and the cut foam 16 after soldering. After the two circuit boards and the cut foam 16 are placed in the battery box housing 15, controller potting compound is poured into the housing, with the amount poured so that the liquid level of the controller potting compound exceeds the top surface of the highest component on the circuit board by at least 5mm. After the controller potting compound cures, the resulting adhesive layer completely encapsulates the two circuit boards, the single-core wire solder joints, and most of the components. The minimum coverage thickness of 5mm ensures that the adhesive layer forms a continuous protective layer above the top surface of the highest component on the circuit board. This protective layer extends the penetration path of external moisture, dust, and coolant to at least 5mm, reducing the probability of external media penetrating the adhesive layer and reaching the circuit board surface. At the same time, the cured adhesive applies a uniform encapsulating force to the circuit board and components, suppressing repeated micro-deformation of component leads and solder joints in the vibration environment of machine tool operation, and reducing the risk of solder joint fatigue fracture. If the potting compound is less than 5mm thick, shrinkage cracks may form near the top surface of the highest component during the curing and shrinkage process. Once the cracks are connected, they form a channel for external media to enter, causing the seal to fail.

[0064] Furthermore, the controller assembly also includes a battery box back cover 12, a fixing hook 10, and a fixing plate 11.

[0065] The battery box rear cover 12 is a cover plate that matches the opening size of the battery box housing 15, and it seals the opening of the housing after mating with the battery box housing 15. After the controller potting compound cures, it forms a protective layer on top of the circuit board. The battery box rear cover 12 adds another physical housing barrier on the outside of the protective layer, so that the controller assembly forms a double-layer protective structure of "potting compound inner layer sealing + housing outer layer sealing". The battery box rear cover 12 and the battery box housing 15 are assembled and fixed together with round head flat tail self-tapping screws.

[0066] The fixing hook 10 and fixing plate 11 are mounted on the outer surface of the battery box rear cover 12. The fixing hook 10 is a curved metal hook that can be hooked onto the crossbeam, guide rail guard edge, or other mounting points with protruding edges on the machine tool body. The fixing plate 11 is a flat metal piece that is fixed to the battery box rear cover 12 with screws, forming a "hooking + abutting" two-point fixation with the fixing hook 10, restricting the controller assembly's displacement freedom in the hooking direction and perpendicular to the hooking direction. The controller assembly is hooked onto the guard edge on the side of the milling machine spindle box via the fixing hook 10, and the plate surface of the fixing plate 11 abuts against the guard surface, so that the controller assembly is stably suspended on one side of the spindle box and connected to the main housing 5 installed near the spindle via a shielded cable. In other embodiments, the controller assembly can also be fixed to the steel surface of the machine tool via a magnetic base, or directly fixed to the pre-reserved mounting holes on the machine tool via bolts. All of the above fixing methods can be selected according to the available mounting points of the specific machine tool model.

[0067] The assembly method of the coolant following device disclosed in the embodiments of this application specifically includes S1-S4.

[0068] S1. Inspect the edge of the water column 2. If there are sharp corners or burrs on the edge of the water column 2, grind and repair the sharp corners or burrs. Apply lubricating grease to the surface of the O-ring 1. Embed the O-ring 1 with lubricating grease into the sealing groove of the water column 2. Push the water column 2 into the mounting hole of the main housing 5 until the thread of the threaded nozzle tube 4 is fully exposed. Verify that the O-ring 1 is not squeezed or damaged.

[0069] The operations of S1 are executed in the following order.

[0070] First, visually inspect the outer edge of the water outlet column 2, paying particular attention to the opening at the top of the water outlet column 2 and the upper and lower edges of the sealing groove. The water outlet column 2 is a machined part, and burrs or small sharp corners due to tool wear may remain on the machined edges. If sharp corners or burrs are found, use fine sandpaper or a file to smooth the edges, creating a smooth chamfered transition surface. After smoothing, run your finger along the edge; if it feels smooth to the touch, it is acceptable. Smoothing is a mandatory pre-installation step for O-ring 1; O-ring 1 installation must not proceed without edge inspection and smoothing.

[0071] Next, place O-ring 1 on a clean surface. Use a cotton swab or your fingertip to apply a thin, even layer of lubricating grease to the outer surface of O-ring 1. After application, align O-ring 1 with the opening of the sealing groove on the outer wall of the water column 2 and insert it radially into the groove. After insertion, visually confirm that O-ring 1 is completely fitted to the bottom of the groove, without any local flipping or protrusion.

[0072] Subsequently, a fixing adhesive is evenly applied to the external thread surface of the end of the threaded nozzle tube 4 that is screwed into the water column 2. This end of the threaded nozzle tube 4 is then aligned with the threaded hole at the top of the water column 2, screwed in along the engagement direction, and tightened. After the fixing adhesive cures in the sealed environment of the threaded mating surface, it locks the threaded connection between the threaded nozzle tube 4 and the water column 2, while filling the micro-gaps between the thread teeth to prevent coolant from seeping along the threaded mating surface. After screwing in, it is visually confirmed that the external thread of the other end of the threaded nozzle tube 4 is fully exposed. This end is used for screwing in the copper nozzle 3 in subsequent S2.

[0073] Next, align the water jet 2, equipped with O-ring 1, with the mounting hole of the main housing 5, and slowly push it in with the threaded end facing outwards and the gear end facing inwards. During the pushing process, the outer surface of O-ring 1 first contacts the chamfered area of ​​the mounting hole, and O-ring 1 begins to be compressed radially. Continue pushing until O-ring 1 is fully inserted into the straight section of the mounting hole, at which point O-ring 1 is evenly compressed around its entire circumference, forming an annular seal. The endpoint of the push is determined by the complete exposure of the external thread of the threaded nozzle tube 4 on the outside of the main housing 5, meaning that the threaded hole at the top of the water jet 2, along with the threaded nozzle tube 4 screwed into it, has passed through the mounting hole and reached the outside of the housing, and the entire thread length of the threaded nozzle tube 4 is located outside the housing, allowing the copper nozzle 3 to be screwed in.

[0074] After pushing in, manually rotate the water column 2 one revolution in the mounting hole to check if the rotation is smooth. If the rotation is smooth and there is no coolant leakage at the sealing groove, the O-ring 1 is considered undamaged, and S1 is complete. If the rotation resistance increases abnormally or visible signs of deformation are found on the surface of the O-ring 1 at the sealing groove, the water column 2 must be removed, the condition of the O-ring 1 checked, and it replaced before the pushing operation is repeated.

[0075] After S1 is completed, the external thread of the threaded nozzle tube 4 is fully exposed on the outside of the main housing 5, and then proceed to S2.

[0076] S2. Apply fixing adhesive to the outer wall of the threaded nozzle tube 4, screw the copper nozzle 3 onto the end of the threaded nozzle tube 4, adjust the spray angle of the copper nozzle 3 to the preset position, and let it stand until the fixing adhesive cures.

[0077] Apply a uniform layer of fixing adhesive around the exposed external thread section of the threaded nozzle tube 4. Control the amount of adhesive applied, ensuring it covers the thread teeth but does not overflow into the inner channel of the threaded nozzle tube 4. If the fixing adhesive enters the inner channel and hardens, it will cause blockage inside the flow channel, reducing the flow area of ​​the coolant or even completely blocking the coolant passage. The application is done by directly dotting the adhesive onto the outer surface of the thread using a glue bottle, evenly distributing 3 to 4 dots along the circumference of the threaded nozzle tube 4. The adhesive spreads spirally under the capillary action of the thread teeth, covering the entire threaded mating area.

[0078] After applying the fixing adhesive, align the M6 ​​internal thread of the copper nozzle 3 with the external thread end of the threaded nozzle tube 4 and screw it in along the engagement direction. During the engagement process, the fixing adhesive is squeezed and expanded between the internal and external thread surfaces, filling the micro-gaps between the surfaces. After the copper nozzle 3 is screwed in place, use a jig to hold the copper nozzle 3 and adjust the nozzle outlet direction to the preset spray angle. The preset spray angle is an angle of approximately 15° to 30° between the nozzle outlet direction and the axis of the water column 2, so that the coolant jet is directed towards the contact area between the milling cutter and the workpiece when the water column 2 rotates to the center position.

[0079] After angle adjustment, keep the fixture clamped and allow the component to stand still. The workable time for the fixative, i.e., the time window from application to the initial curing of the adhesive, is typically 3 to 10 minutes. Within this time window, the copper nozzle 3 must be engaged and its angle adjusted. After initial curing, the adhesive loses its fluidity, and the angle of the copper nozzle 3 is locked. Full curing typically takes 12 to 24 hours. After full curing, the fixative reaches its design shear strength, and the threaded connection forms a non-removable permanent fixation. Before full curing, no external force should be applied to the nozzle or subsequent assembly operations should be performed to avoid damaging the bonding surface before the adhesive reaches its design strength.

[0080] After the fixing adhesive in S2 has fully cured, the angle of the nozzle assembly is locked, and then proceed to S3.

[0081] S3. Drive the servo motor 7 to the set angle in advance through the controller assembly, install the servo motor 7 into the servo motor 7 mounting position from the back of the main housing 5 and make the output end of the servo motor 7 mesh with the gear hole of the water column 2, perform a full stroke rotation verification on the water column 2 to confirm that the rotation is flexible and without jamming, in response to the full stroke rotation verification passing, weld the servo motor wire and the shielding wire of the servo motor 7 according to the preset wire sequence and put heat shrink tubing on the weld, inject potting compound into the assembly area between the servo motor 7 and the main housing 5, and fix the main housing cover 9 to the main housing 5.

[0082] The internal operating procedures of the S3 are sequentially connected as follows: pre-adjustment and angle setting → installation and engagement of servo motor 7 → full-stroke rotation verification → welding cables and applying heat shrink tubing → injection of potting compound → fixing of main housing cover 9. There are strict prerequisite relationships between the above six operating steps.

[0083] Pre-adjustment is a prerequisite for engagement. In its unpowered, free state, the output angle of servo motor 7 is uncertain and may remain at any position within its rotation range. If servo motor 7 is installed at this unknown angle, the teeth at its output end may misalign and collide with the tooth grooves of the gear hole, causing damage to the teeth or jamming. By pre-driving servo motor 7 to a known set angle via the controller assembly, the orientation of the output teeth becomes predictable. The operator can then adjust the orientation of the gear hole of the water jet 2 accordingly to align them before pushing it into engagement, reducing the risk of tooth collision.

[0084] Full-stroke rotation verification is a prerequisite for welding and potting. Passing the verification indicates that the meshing between the output end of servo motor 7 and the gear hole is normal, and the water jet 2 can be driven to rotate by servo motor 7 throughout its full stroke. If the verification fails, servo motor 7 has not yet been fixed inside the housing with potting compound, and the operator can still remove servo motor 7 from its mounting position and repeat the pre-adjustment and reinstallation operations. Once the welding and potting steps begin, the operation is irreversible: the welded cable cannot be disassembled without damage, and after the potting compound cures, servo motor 7 is permanently fixed inside the housing. If any jamming or misalignment is found at this point, the entire main housing 5 assembly must be scrapped. Therefore, full-stroke rotation verification, as the last reversible checkpoint for irreversible operations, must be scheduled before welding and potting in the process sequence.

[0085] Optionally, S3 includes the following sub-steps S31-SS5.

[0086] S31. Connect the servo motor 7 to the controller assembly via the test cable, and drive the servo motor 7 to rotate to the set angle via the controller assembly.

[0087] The test cable is a temporary connection cable. One end is inserted into the signal interface of servo motor 7, and the other end is connected to the output port of the controller component. After connection, the controller component is powered on and sends an angle control signal. After receiving the signal, servo motor 7 rotates its output end to the set angle specified by the signal and holds it. The set angle is 90°, which is the midpoint of the servo motor 7's output angle range of 0° to 180°. The midpoint is chosen as the set angle because, in the midpoint state, the tooth surface of the servo motor 7's output end is located at the geometric center of the rotation range, and the alignment tolerance between the tooth surface orientation and the initial tooth groove position of the gear hole is the largest, giving the operator the largest angle adjustment margin during subsequent engagement operations.

[0088] After S31 and before S32, the following steps are also included: removing the parts at both ends of the servo 7 that interfere with the assembly of the main housing 5, and attaching double-sided tape to the top of the servo 7.

[0089] After the servo motor 7 is rotated to the set angle, disconnect the test cable. Remove the servo motor 7 and visually inspect both ends of the servo motor 7 housing for any protruding structures. If there is a protruding part that interferes with the inner wall of the servo motor 7 mounting position on the main housing 5, use a file or grinding wheel to remove the protruding part until it is flush with the outline of the main housing body. After removal, tentatively place the servo motor 7 into the mounting position to confirm that there is no squeezing interference between the servo motor 7 housing and the inner wall of the mounting position. Then, stick a piece of double-sided tape to the center area of ​​the top surface of the servo motor 7, covering the main area of ​​the top surface of the servo motor 7. After sticking, peel off the release paper on the outside of the double-sided tape to expose the adhesive surface. The above interference removal and double-sided tape sticking operations are performed after S31 because in S31, the servo motor 7 needs to be connected to the test cable and powered on for rotation. At this time, the servo motor 7 is in a free state for easy operation. Removing interference and sticking double-sided tape are physical preparations for the installation operation in S32, ensuring that the servo motor 7 meets the installation requirements in terms of both shape and fixing conditions before installation.

[0090] S32. Install the servo motor 7 from the back of the main housing 5 into the servo motor 7 mounting position, and adjust the position of the servo motor 7 so that the output end of the servo motor 7 meshes with the gear hole of the water outlet 2.

[0091] The servo motor 7 is pushed in from the back of the main housing 5 towards the mounting position, with its output end facing the gear hole at the bottom of the water jet 2. During the pushing process, the operator needs to pay attention to two alignment relationships simultaneously: first, the angular alignment of the cross-sectional profile of the servo motor 7's output end with the cross-sectional profile of the gear hole; and second, the coaxial alignment of the servo motor 7's output axis with the axis of the gear hole. Angular alignment relies on the pre-adjustment in S31, i.e., the servo motor 7's output end is already at the set angle position. The operator rotates the gear hole of the water jet 2 to the receiving position corresponding to the tooth surface of the output end before pushing it in. Coaxial alignment relies on the geometric positioning of the mounting position, i.e., the central axis of the mounting position is designed to maintain a fixed offset relationship with the central axis of the mounting hole. After the servo motor 7 falls into the mounting position, it naturally aligns axially with the gear hole. After pushing in, the double-sided adhesive on the top surface of the servo motor 7 contacts and adheres to the inner wall of the housing, initially fixing the position of the servo motor 7.

[0092] S33. Manually rotate the water column 2 to confirm that the water column 2 rotates flexibly, without jamming or deviation, throughout its entire stroke range.

[0093] Pinch the part of the water jet 2 that extends beyond the outer edge of the housing with your fingers, and slowly rotate the water jet 2 clockwise to the end of its stroke, then rotate it counterclockwise to the other end of its stroke, completing a full round trip. During the rotation, feel for any points of resistance, i.e., a sudden increase in rotational resistance at a certain angle that requires additional force to overcome. If there are points of resistance, the cause may be excessively tight meshing of the gear teeth or foreign objects between the output end of the servo motor 7 and the gear hole. After rotating to the end of the stroke, release your hand and observe whether the water jet 2 remains stably in the released position. If the water jet 2 deflects away from the released position due to its own weight or uneven friction after release, it is considered to have deviated, which may be caused by uneven clearance of the gear teeth or inconsistent circumferential distribution of the friction torque of the O-ring 1. The verification is successful only if all three conditions are met simultaneously: smooth rotation throughout the entire stroke, no resistance, and no deviation.

[0094] S34. In response to the successful verification of S33, the servo wire and shield wire of servo motor 7 are soldered in the preset wiring sequence, and heat shrink tubing is applied to the solder joint and heated to shrink it.

[0095] S33. After successful verification, proceed to the irreversible operation stage. Strip the copper insulation from the ends of the three core wires of the servo cable and the three core wires of the shielding cable. Then, tin the corresponding core wires according to the preset wiring sequence and solder them together. After soldering, visually inspect each solder joint for any cold solder joints or bridging. Next, slide the heat shrink tubing pre-insulated on the cable to the soldering point, ensuring that the heat shrink tubing covers all solder joints and at least 5mm of the cable sheath at both ends. Use a heat gun to evenly heat the heat shrink tubing, causing it to shrink radially until it adheres tightly to the solder joint and cable surface, forming a continuous insulating coating.

[0096] S35. Inject potting compound into the assembly area between the servo 7 and the main housing 5 to fix the main housing cover 9 to the main housing 5.

[0097] Use a glue gun or applicator to inject potting compound into the gap between the servo 7 housing and the inner wall of the main housing 5. The injection points are the cavities between the side and bottom surfaces of the servo 7 housing and the inner wall of the housing. The potting compound, in its liquid state, fills the irregular gaps in the cavities due to its own fluidity. The upper limit for the injection volume is that the potting compound level reaches two-thirds of the height of the servo 7 housing side surface; the potting compound level must not rise to near the meshing area between the gear hole and the output end of the servo 7. After injection, align the main housing cover 9 with the mounting position on the back of the main housing 5 and tighten it using four M2×6 socket head cap screws 8, with a tightening torque of 0.8 N·m. After the main housing cover 9 is fixed, the potting compound is sealed inside the housing and will not overflow from the back during the curing process.

[0098] Optionally, after the verification in S33 is passed and before S34, the following steps are also included: powering on the servo motor 7, driving the servo motor 7 to rotate back and forth within a set angle range, and confirming that the water jet 2 follows the rotation of the servo motor 7 without any abnormal noise.

[0099] The manual rotation verification of S33 only tested the passive rotation state of the water column 2 under conditions without a power source, that is, the water column 2 was driven to rotate by a manual torque application, and the output end of the servo motor 7 passively followed as a driven component. This verification can detect the static smoothness of the tooth surface engagement, but it cannot cover the dynamic transmission condition when the servo motor 7 is the driving component and actually outputs torque. Under dynamic conditions, the rotational speed, acceleration, and output torque of the servo motor 7 output end are all determined by the controller signal, and the contact state, load distribution, and vibration characteristics between the tooth surfaces are different from those of static passive rotation. For example, the meshing depth of the tooth surfaces is slightly shallower within a certain angle range. During static manual rotation, no obvious change in resistance is felt in this section, but when the servo motor 7 passes through this section at a set speed under dynamic drive, it may produce tooth surface slippage or periodic impact sounds due to insufficient contact area.

[0100] The power-on verification process is as follows: reconnect the test cable to the servo motor 7 and the controller assembly. After the controller assembly is powered on, it sends a reciprocating rotation command, driving the servo motor 7 to reciprocate within a set angle range. Based on the aforementioned median angle parameters, the servo motor 7 reciprocates for three complete cycles within an angle range of 60° to 120°. During the reciprocating rotation, the operator simultaneously observes and listens to two indicators: first, whether the water jet 2 follows the servo motor 7 to the same angular position in each cycle, i.e., consistency of following; second, whether any abnormal sounds are generated during the rotation.

[0101] If the follow-through is consistent and there are no abnormal noises, the power-on verification is considered passed. After disconnecting the test line, proceed to S34. If the water jet 2 does not follow the flow consistently, for example, if the servo motor 7 has rotated to the target angle but the water jet 2 lags behind or the angle deviation exceeds the perceptible range, the possible causes are excessive meshing clearance or localized wear on the tooth surface. If abnormal noises are detected, the possible causes are interference friction caused by excessively tight tooth fit or foreign particles in the meshing area. Both of these failure scenarios occur before welding in S34 and potting in S35, when the servo motor 7 has not yet been irreversibly fixed in the housing. The operator can remove the servo motor 7 from its mounting position, check the tooth surface condition, remove foreign objects, or replace the servo motor 7 before re-executing from S31.

[0102] S4. Assemble the controller assembly and electrically connect the controller assembly to the servo motor 7.

[0103] After the potting compound is injected in S3 and the main housing cover 9 is fixed, proceed to S4.

[0104] The assembly of the controller components shall be performed in the following order. Connect the servo motor insertion board 13 and the servo motor adapter board 14 one by one using single-core wires. Before soldering each single-core wire, confirm that the corner numbers of the corresponding pads on the two boards are consistent. After soldering, visually inspect the solder joints for any cold solder joints or bridging. Cut the foam 16 to the outer contour shape of the indicator light and attach it around the indicator light on the servo motor insertion board 13. The height of the foam should be higher than the preset level of the potting compound. Place the two soldered circuit boards and the cut foam 16 into the battery box housing 15, and adjust the board position so that each interface terminal faces the cable lead-out holes of the housing.

[0105] Fill the battery box housing 15 with controller potting compound, ensuring the compound level exceeds the top surface of the highest component on the circuit board by at least 5mm, while maintaining the compound level below the height of the cut foam 16 dike, thus exposing the indicator light surface. After potting, allow the controller potting compound to fully cure. Once cured, fit the battery box back cover 12 into the battery box housing 15 and secure it with round-headed, flat-tailed self-tapping screws. Install the fixing hook 10 and fixing plate 11 onto the outer surface of the battery box back cover 12.

[0106] The assembled controller assembly is hooked onto the edge of the guard on the side of the milling machine spindle box using the fixing hook 10. The surface of the fixing plate 11 abuts against the outer surface of the guard, forming a stable suspension. The output terminal of the shielded wire of the controller assembly is connected to the input terminal of the shielded wire already soldered to the servo wire in S34, completing the electrical connection between the controller assembly and the servo 7. After powering on and sending an angle command, the servo 7 responds and rotates, confirming that the electrical connection is normal. S4 is then complete.

[0107] Optionally, in S3, after injecting the potting compound and fixing the main housing cover 9 to the main housing 5, the assembled component is flipped so that the gear hole of the water column 2 faces upward, and the flipped position is maintained until the potting compound has cured. In S4, assembling the controller assembly includes injecting controller potting compound into the controller assembly. The injection of controller potting compound is performed independently of the injection of potting compound in S3.

[0108] After the potting compound in S35 is injected into the housing and the main housing cover 9 is locked, the potting compound is in a liquid state and has not yet cured. At this time, the potting compound inside the housing continues to flow under the action of gravity, tending to fill all accessible low-lying spaces in the cavity. Although the meshing surfaces between the gear hole and the output end of the servo motor 7 are tightly fitted, there is still a meshing gap of no more than 0.1mm between the gear teeth. Under the combined action of capillary effect and gravity, the liquid potting compound may seep into the meshing surfaces along this gap. If the potting compound seeps into the meshing surfaces and cures there, the gear teeth will be bonded together by the compound, and the rotational torque of the output end of the servo motor 7 cannot be transmitted to the water outlet 2. The water outlet 2 will be locked at the angle position when it is cured, and the device will lose its angle adjustment function. Since the potting compound cannot be dissolved or peeled off after curing, the meshing surfaces being locked by the potting compound is an irreparable assembly defect, and the entire main housing 5 assembly needs to be scrapped.

[0109] The flipping operation is performed immediately after the main housing cover 9 is locked. The assembled component is flipped 180° so that the gear hole of the water outlet 2 is facing upwards, with the output end of the servo motor 7 directly below the gear hole. After flipping, the potting compound settles from the gear hole area towards the bottom of the housing, away from the gear hole, under gravity. The meshing surface is located at the highest point of the cavity. Under gravity, the liquid level of the potting compound moves away from the meshing surface. The upward penetration force generated by capillary effect must overcome the weight of the potting compound to push it upwards into the meshing gap. Due to the combined constraints of the potting compound viscosity and the gap size, the capillary penetration height is much smaller than the vertical distance between the meshing surface and the liquid level, and the potting compound cannot reach the meshing surface. The flipped position is maintained until the potting compound is completely cured. After curing, the compound loses its fluidity, and even if the component is returned to its original position, the cured compound will not shift.

[0110] The timing constraint for the inversion operation is that it must be completed after the potting compound is injected but before it begins its initial curing. The operable time window between injection and the start of initial curing is typically 10 to 30 minutes. Within this window, the potting compound maintains its liquid fluidity, allowing it to settle sufficiently under gravity after inversion. If this time window is missed, the potting compound will have partially gelled and lost its fluidity, and the inversion operation will not alter its distribution within the cavity.

[0111] The potting compound used to fill the controller assembly in S4 and the potting compound used to fill the main housing 5 in S3 are two independent potting operations. The two potting areas are completely separated physically; that is, the main housing 5 cavity and the battery box housing 15 are each sealed, connected only by a shielded cable without any adhesive bonding. Independent potting ensures that the potting operations of the two areas do not affect each other. If defects such as air bubbles, insufficient coverage, or overflow occur in one area, only that area needs to be reworked, without affecting the completed potting in the other area. Furthermore, different types of potting compounds or those with different curing conditions can be selected for the two areas. For example, a high-temperature resistant potting compound can be used in the main housing 5 area to accommodate heat conduction during cutting, while a low-stress potting compound can be used in the controller area to reduce stress damage to electronic components.

[0112] Optionally, heat shrink tubing is first applied to the weld joint between the servo cable and the shielding cable to form the first layer of insulation and sealing. Then, potting compound is used to cover the weld area to form the second layer of liquid penetration protection. The two protection mechanisms complement each other.

[0113] After shrinking, the heat shrink tubing forms a continuous insulating layer at the weld joint, isolating the weld from the external environment. At the microscopic level, there are micro-gaps between the ends of the heat shrink tubing and the cable sheath. Under conditions of continuous coolant splashing, droplets may enter the heat shrink tubing through these micro-gaps via capillary penetration and contact the weld. When the potting compound is injected into the housing in S35, the liquid potting compound simultaneously covers the welded area where the heat shrink tubing has been fitted, filling the micro-gaps between the heat shrink tubing ends and the cable sheath. After curing, it forms a second, fully encapsulated sealing layer on the outer surface of the heat shrink tubing. The insulation function of the heat shrink tubing focuses on preventing electrical short circuits between the weld joints, while the sealing function of the potting compound focuses on preventing liquid penetration to the weld surface. The two layers of protection have different failure mechanisms; if one layer fails, the other layer can still maintain its protective function.

[0114] In some embodiments, during the curing period of the potting compound in the servo motor 7 area, the assembly of the controller assembly is performed in parallel to shorten the total assembly time. After the potting compound is injected and flipped in S35, the assembly needs to remain in the flipped position to wait for the potting compound to fully cure, which typically takes several hours. During this waiting period, the operator does not need to continuously monitor the flipped main housing 5 assembly and can simultaneously begin the assembly of the controller assembly in S4, including welding of the plug-in board and adapter board, foam bonding, installation of the battery box housing 15, and potting of the controller potting compound. The assembly of the controller assembly does not involve any parts of the main housing 5 assembly, and the two assembly lines do not conflict in terms of materials and workstations, and can be performed in parallel in terms of time. Parallel assembly reduces the total assembly time from "main housing 5 assembly time + curing waiting time + controller assembly time" to "main housing 5 assembly time + max(curing waiting time, controller assembly time)". In the typical case where the potting compound curing time is much longer than the controller assembly time, the controller assembly time is completely hidden within the curing waiting period, and the total time is reduced by approximately the length of one controller assembly time.

[0115] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0116] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0117] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A coolant following device, characterized in that, include: The main housing (5) is provided with mounting holes and a servo motor (7) mounting position; The water outlet column (2) is rotatably disposed in the mounting hole. The outer wall of the water outlet column (2) is provided with a sealing groove. The bottom of the water outlet column (2) is provided with a gear hole. The top of the water outlet column (2) is provided with a threaded hole. O-ring (1) is embedded in the sealing groove to seal the gap between the water column (2) and the wall of the mounting hole; The threaded nozzle tube (4) is screwed into the threaded hole at one end, and the outer wall of the threaded nozzle tube (4) is coated with a fixing adhesive. A copper nozzle (3) is screwed and fixed to the other end of the threaded nozzle tube (4); A servo motor (7) is installed in the mounting position of the servo motor (7), and the output end of the servo motor (7) meshes with the gear hole to drive the water jet (2) to rotate in the mounting hole; The main housing cover (9) is fixedly connected to the main housing (5), and the main housing cover (9) and the main housing (5) enclose a cavity to accommodate the servo motor (7); Potting compound is applied to the assembly area between the servo motor (7) and the main housing (5) to cover the connection between the servo motor (7) and the main housing (5); as well as The controller assembly is electrically connected to the servo motor (7) and is used to send angle control signals to the servo motor (7).

2. The coolant following device according to claim 1, characterized in that, The O-ring (1) is made of fluororubber and the surface of the O-ring (1) is coated with lubricating grease; the edge of the water outlet column (2) is polished to eliminate sharp corners.

3. The coolant following device according to claim 1, characterized in that, The meshing clearance between the output end of the servo motor (7) and the gear hole is no greater than 0.1 mm; the two ends of the servo motor (7) are free of parts that interfere with the assembly of the main housing (5); double-sided tape is pasted on the top of the servo motor (7).

4. The coolant following device according to claim 1, characterized in that, It also includes a cable connection structure, which includes: The shielding wire is welded to the servo wire of the servo motor (7) according to a preset wiring sequence; and Heat shrink tubing is fitted onto the weld joint between the servo cable and the shielding cable.

5. The coolant following device according to claim 1, characterized in that, The controller component includes: Servo plug-in board (13) and servo adapter board (14), the servo plug-in board (13) and the servo adapter board (14) are connected by welding with single core wire, and the corner positions correspond one to one; Cut the foam (16) and attach it around the indicator light on the servo plug-in board (13); Battery housing (15) for accommodating the servo plug-in board (13) and the servo adapter board (14); and The controller potting compound is filled inside the battery box housing (15) and covers the servo plug-in board (13) and the servo adapter board (14). The filling thickness of the controller potting compound is not less than 5 mm.

6. The coolant following device according to claim 5, characterized in that, The controller component also includes: The battery box rear cover (12) is fitted and sealed with the battery box housing (15); The fixing hook (10) and fixing plate (11) are installed on the rear cover (12) of the battery box for fixing the controller assembly to the machine tool.

7. A method for assembling a coolant follower device, used for assembling a coolant follower device as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Inspect the edge of the water column (2). If there are sharp corners or burrs on the edge of the water column (2), grind and repair the sharp corners or burrs. Apply lubricating grease to the surface of the O-ring (1). Embed the O-ring (1) after applying lubricating grease into the sealing groove of the water column (2). Push the water column (2) into the mounting hole of the main housing (5) until the thread of the threaded nozzle tube (4) is completely exposed. Verify that the O-ring (1) is not crushed or damaged. S2. Apply the fixing adhesive to the outer wall of the threaded nozzle tube (4), screw the copper nozzle (3) to the end of the threaded nozzle tube (4), adjust the spray angle of the copper nozzle (3) to the preset position, and let it stand until the fixing adhesive cures. S3. Drive the servo motor (7) to a set angle in advance through the controller assembly, install the servo motor (7) from the back of the main housing (5) into the servo motor (7) mounting position and make the output end of the servo motor (7) mesh with the gear hole of the water outlet column (2), perform a full stroke rotation verification on the water outlet column (2) to confirm that the rotation is flexible and without jamming, in response to the full stroke rotation verification being passed, weld the servo motor wire and the shielding wire of the servo motor (7) in a preset wire sequence and put heat shrink tubing on the weld, inject the potting compound into the assembly area between the servo motor (7) and the main housing (5), and fix the main housing cover (9) to the main housing (5). S4. Assemble the controller assembly and electrically connect the controller assembly to the servo motor (7).

8. The assembly method according to claim 7, characterized in that, S3 includes the following sub-steps: S31. Connect the servo motor (7) to the controller assembly via a test cable, and drive the servo motor (7) to rotate to a set angle via the controller assembly; S32. Install the servo motor (7) from the back of the main housing (5) into the servo motor (7) mounting position, and adjust the position of the servo motor (7) so that the output end of the servo motor (7) meshes with the gear hole of the water outlet column (2); S33. Manually rotate the water column (2) to confirm that the water column (2) rotates flexibly, without jamming or deviation, within the full stroke range; S34. In response to the successful verification of S33, the servo wire and the shield wire of the servo motor (7) are welded in a preset sequence, and a heat shrink tube is fitted at the weld and heated to shrink. S35. Inject the potting compound into the assembly area between the servo (7) and the main housing (5) to fix the main housing cover (9) to the main housing (5). After S31 and before S32, the following steps are also included: removing the parts at both ends of the servo (7) that interfere with the assembly of the main housing (5), and attaching double-sided tape to the top of the servo (7).

9. The assembly method according to claim 8, characterized in that, After the verification in S33 is passed and before S34, the following steps are also included: Power on the servo motor (7) and drive it to rotate back and forth within a set angle range. Confirm that the water jet (2) rotates with the servo motor (7) without any abnormal noise.

10. The assembly method according to claim 7, characterized in that, In step S3, after injecting the potting compound and fixing the main housing cover (9) to the main housing (5), the assembled component is flipped so that the gear hole of the water outlet column (2) faces upward, and the flipped position is maintained until the potting compound is cured; in step S4, assembling the controller component includes injecting controller potting compound into the controller component, and the injection of the controller potting compound is performed independently of the injection of the potting compound in step S3.

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