Transmission mechanism and electric chuck

Abstract

A transmission mechanism (200) and an electric chuck. The transmission mechanism (200) comprises a lead screw (201), a lead screw nut (202), and a pull rod connecting shaft (204). The lead screw (201) is provided with a power connection end connected to a power mechanism (100), and the lead screw (201) rotates under the drive of the power mechanism (100). The lead screw nut (202) is located in front of the power connection end. The lead screw nut (202) is sleeved on the outer circumference of the lead screw (201), the lead screw nut (202) is matched with the lead screw (201) by means of threads, and the lead screw nut (202) is driven by the rotation of the lead screw (201) to move back and forth along the axial direction. The pull rod connecting shaft (204) is located in front of the lead screw nut (202), the pull rod connecting shaft (204) is connected to the lead screw nut (202), the pull rod connecting shaft (204) is driven to move axially by an axial movement of the lead screw nut (202), and the pull rod connecting shaft (204) is configured to drive a clamping jaw transmission assembly (300) to move axially. The transmission mechanism (200) can convert a rotation output of the power mechanism (100) such as a motor (101) into a linear movement and output same to the clamping jaw transmission assembly (300) and a clamping jaw (400), so as to implement a clamping action or an opening action of the clamping jaw (400).

Description

Transmission mechanism and electric chuck

[0001] This application claims priority to the Chinese patent application filed with the Patent Office of China on August 23, 2023, with application number 202311065478.8 and application name “A Transmission Mechanism and Electric Chuck”. The entire contents of the application are incorporated by reference into this application. Technical Field

[0002] The present invention belongs to the technical field of chucks, and in particular relates to a transmission mechanism and an electric chuck. Background Art

[0003] A chuck is a mechanical device used to clamp workpieces on machine tools. It is a machine tool accessory that clamps and positions the workpiece by radially moving movable jaws evenly distributed on the chuck body. A chuck generally consists of three parts: the chuck body, the movable jaws, and the jaw drive mechanism. The chuck body has a minimum diameter of 65 mm and a maximum of 1500 mm, with a central through-hole to allow passage of the workpiece or bar stock. The back has a cylindrical or short tapered structure that connects directly or via a flange to the end of the machine tool spindle. Chucks are typically installed on lathes, external and internal cylindrical grinders, and can also be used in conjunction with various indexing devices for milling and drilling machines. Existing mainstream chucks can be categorized based on the power used: manual chucks, pneumatic chucks, and hydraulic chucks.

[0004] CN214290904U discloses a six-jaw centering floating back-pull chuck (please refer to Figure 1), which includes a chuck body 1, a connecting base 2, a gas distribution plate 3, a connecting rod 4, a pull rod 5, a floating roller 6, a floating spacer 7, a floating connecting plate 8, a floating oblique rod 9, a centering oblique rod 10, and a fixed clamping jaw 11. One end of the chuck body 1 is provided with a connecting base 2, and the other end of the chuck body 1 is provided with an gas distribution plate 3. A connecting rod 4 is provided in the middle of the chuck body 1 and the connecting base 2. One end of the connecting rod 4 is connected to the pull rod 5. A floating roller 6 is connected to the connecting rod 4. The floating roller 6 is connected to the floating spacer 7. The floating spacer 7 is connected to the floating connecting plate 8. The two ends of the floating connecting plate 8 are respectively connected to the floating oblique rod 9 and the centering oblique rod 10. The floating oblique rod 9 and the centering oblique rod 10 are connected to the fixed clamping jaw 11. The fixed clamping jaw 11 is fixed with a workpiece 12. The pull rod 5 is fitted with a collar 13, to which an oil distribution pipe 14 is connected. The fixed jaws 11 are arranged in a 360-degree annular pattern and comprise three centering jaws and three floating jaws. The hydraulic cylinder drives the pull rod 5, which in turn moves the connecting rod 4, achieving the clamping action of the three centering jaws. Further downward movement of the connecting rod 4 drives the floating roller 6, which is connected to the floating spacer 7, achieving the clamping action of the three floating jaws.

[0005] CN115476050A discloses a cylinder external laser tube cutting chuck (please refer to FIG2 ). When the cylinder 5 is inflated, the piston rod 52 of the cylinder 5 extends forward, and the connecting flange 53 provided on the piston rod 52 is driven by the left and right clamping jaw transmission assembly 6, so that the two left and right clamping jaws 41 move from the open state to the left and right centripetal movement to clamp the workpiece. At the same time, the cylinder body 51 of the cylinder 5 moves backward, and the two front and rear clamping jaws 42 move synchronously from the open state to the upper and lower centripetal movement to clamp the workpiece through the drive plate connecting rod 55 and the cylinder body drive plate 54 and the up and down clamping jaw transmission assembly 7. Among them, the action process of the left and right clamping jaw transmission assembly 6 is: with the connecting flange 53, the left and right clamping jaws 41 move from the open state to the upper and lower centripetal movement to clamp the workpiece. The pull rod connector 62, fixed to the flange 53, transmits the forward thrust of the piston rod 52 through the first pull rod 61, the support connector 63, the two second angular contact ball bearings 64, the first push block 67, the two first levers 68, and the two first sliders 69, causing the two left and right clamping jaws 41 to perform a centripetal clamping action. The vertical clamping jaw transmission assembly 7 operates as follows: the second pull rod 71, whose rear end is locked to the cylinder drive plate 54 by the pull rod locking nut 72, transmits the backward pulling force of the cylinder 51 through the two third angular contact ball bearings 73, the second push block 76, the two second levers 77, and the two second sliders 78, causing the two vertical clamping jaws 42 to perform a centripetal clamping action. When the cylinder 5 is exhausted, the opposite action is performed, and the two left and right clamping jaws 41 and the two vertical clamping jaws 42 perform a reset motion.

[0006] In the prior art, in order for the jaws to clamp or release the workpiece, the jaw transmission assembly (usually a pull rod) is generally required to move linearly back and forth to drive each jaw to perform a centripetal clamping action to clamp the workpiece, or to drive each jaw to perform an opening action to release the workpiece. Since the oil cylinder and other driving devices are generally linear motion output devices, and the pull rod also moves linearly when used with the jaws, the output end of these linear motion output devices can be directly connected to the pull rod to achieve the clamping action or opening action of the jaws. The motor generally outputs power by rotation. At the execution level, it has a fast response speed and can be precisely controlled. However, it is difficult to convert the torque during its rotation into linear motion of the pull rod in the chuck. That is, it is difficult for the motor to directly connect the output end to the pull rod to achieve the clamping action or opening action of the jaws.

[0007] Summary of the Invention

[0008] In view of the deficiencies in the prior art, the present invention provides a transmission mechanism and an electric chuck.

[0009] The present invention provides a transmission mechanism, which includes a screw, a screw nut and a pull rod connecting shaft; the screw is provided with a power connecting end for connecting to a power mechanism, and the screw rotates under the drive of the power mechanism; the screw nut is located in front of the power connecting end, the screw nut is sleeved on the outer periphery of the screw, the screw nut and the screw are matched with each other through a thread, and the screw nut moves back and forth in the axial direction under the rotation of the screw; the pull rod connecting shaft is located in front of the screw nut, the pull rod connecting shaft is connected to the screw nut, and when the screw nut moves axially, it drives the pull rod connecting shaft to move axially, and the pull rod connecting shaft is used to drive the clamp transmission assembly to move axially.

[0010] The transmission mechanism provided by the present invention can convert the rotational output of a power mechanism such as a motor into a linear motion output to the clamping jaw transmission assembly and the clamping jaw, thereby realizing the clamping action or opening action of the clamping jaw.

[0011] Preferably, the transmission mechanism also includes a transmission housing, the lead screw, lead screw nut and pull rod connecting shaft are arranged in the transmission housing, the pull rod connecting shaft is provided with a conveying channel running through it axially, and the pull rod connecting shaft is provided with heat dissipation holes along its radial direction, and the heat dissipation holes are respectively connected to the cavity of the transmission housing and the conveying channel.

[0012] Preferably, the outer side wall of the pull rod connecting shaft is provided with a windward surface, and the windward surface is located at the periphery of the heat dissipation through hole; or

[0013] A spiral blade is provided on the outer side wall of the pull rod connecting shaft close to the heat dissipation through hole. The spiral blade extends radially along the pull rod connecting shaft and is located inside the heat dissipation through hole. When the pull rod connecting shaft rotates, the spiral blade is driven to rotate.

[0014] Preferably, the front end of the screw is socketed with the rear end of the pull rod connecting shaft, and the screw and the pull rod connecting shaft are coaxially arranged; the screw and the pull rod connecting shaft are respectively provided with a conveying channel, and the conveying channels of the two are connected, and the conveying channel axially passes through the front and rear ends of the screw, and the other conveying channel axially passes through the front and rear ends of the pull rod connecting shaft.

[0015] Preferably, the rear end of the pull rod connecting shaft is sleeved on the front end of the screw, and the screw is also integrally provided with a limit block in front of the screw nut, and the limit block is raised compared to the outer peripheral wall of the screw; the limit block limits the forward movement of the screw nut.

[0016] Preferably, the transmission mechanism also includes a transmission housing, a sliding seat and a graphite copper sleeve, the sliding seat and the graphite copper sleeve are arranged in the transmission housing, the graphite copper sleeve is arranged outside the sliding seat, and the outer wall of the graphite copper sleeve is slidingly connected to the transmission housing; one end of the sliding seat sleeve is sleeved outside the screw nut and fixedly connected to the screw nut; the other end of the sliding seat sleeve is sleeved outside the pull rod connecting shaft and fixedly connected to the pull rod connecting shaft; the inner wall surface of the transmission housing is provided with a radially outwardly concave limiting groove, and the limiting groove extends axially; an anti-rotation pin is also provided on the outer wall of the sliding seat sleeve, and the end of the anti-rotation pin away from the outer wall of the sliding seat sleeve is slidably connected in the limiting groove.

[0017] Preferably, the transmission mechanism also includes two double-row angular contact ball bearings; the inner ring of one double-row angular contact ball bearing is connected to the outer peripheral wall of the screw near the power connection end, and its outer ring is fixedly connected to the inner peripheral wall of the transmission housing; the inner ring of the other double-row angular contact ball bearing is mounted on the pull rod connecting shaft, and its outer ring is installed on the inner peripheral wall of the sliding seat.

[0018] On the other hand, the present invention provides an electric chuck, which also includes a power mechanism, a jaw transmission assembly, a jaw and the above-mentioned transmission mechanism; the output end of the power mechanism is connected to the screw power connection end of the transmission mechanism, and the power mechanism drives the screw to rotate; the input end of the jaw transmission assembly is connected to the pull rod connecting shaft of the transmission mechanism, and the output end of the jaw transmission assembly is connected to the jaw, and the jaw transmission assembly moves in the axial direction under the drive of the pull rod connecting shaft, and the jaw performs a centripetal clamping action or an opening action under the drive of the jaw transmission assembly.

[0019] Preferably, the power mechanism includes a motor and a reducer, the reducer is located in front of the motor, the output end of the reducer is connected to the connection end of the screw power, and the input end of the reducer is connected to the output end of the motor through one of the following driving connections:

[0020] The input end of the reducer and the output end of the motor are respectively provided with an input gear and an output gear, and the output gear is meshed with the input gear; or the input end of the reducer and the output end of the motor are provided with a synchronous belt; or the input end of the reducer and the output end of the motor are provided with a transmission belt; or the input end of the reducer and the output end of the motor are connected via a coupling.

[0021] Preferably, the lead screw and pull rod connecting shaft are respectively provided with conveying channels, and the conveying channels of the two are connected; the clamp transmission assembly includes a pull rod, the output end of the pull rod is connected to the clamp, and the pull rod is also provided with a conveying channel along the axial direction, and the conveying channel of the pull rod is connected to the conveying channel of the pull rod connecting shaft; the input end of the reducer and the output end of the motor are respectively provided with meshing input gears and output gears, or the input end of the reducer and the output end of the motor are respectively provided with pulleys, and the pulleys of the two are connected by a transmission belt; the input end of the reducer is a hollow output shaft, and the hollow output shaft passes through the reducer body, and the front and rear ends of the hollow output shaft protrude compared to the reducer body, and the hollow output shaft is connected to the conveying channel, and the hollow output shaft can convey the cooling medium or workpiece into the conveying channel, and the conveying channel conveys the cooling medium or workpiece to the clamp. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and other purposes, features and advantages of the present invention will become more apparent by describing in more detail the preferred embodiments of the present invention shown in the accompanying drawings. The same reference numerals indicate the same parts throughout the accompanying drawings, and the drawings are not intentionally scaled to actual size, but rather are intended to illustrate the subject matter of the present invention.

[0023] FIG1 is a schematic diagram of a structure in which a clamping jaw is driven by an oil cylinder in the prior art;

[0024] FIG2 is a schematic diagram of the structure of the clamp driven by the cylinder in the prior art

[0025] FIG3 is a schematic structural diagram of a power mechanism provided in the first embodiment;

[0026] FIG4 is a schematic structural diagram of a power mechanism provided in a second embodiment;

[0027] FIG5 is another cross-sectional view of the power mechanism provided by the second embodiment;

[0028] FIG6 is a schematic structural diagram of another embodiment of a pull rod connecting shaft;

[0029] FIG7 is a schematic structural diagram of an electric chuck provided in an embodiment;

[0030] FIG8 is a schematic structural diagram of a chuck provided in an embodiment;

[0031] FIG9 is a cross-sectional view of the pull rod connecting shaft.

[0032] Illustrations: Power mechanism 100, motor 101, output gear 102, reducer 103, input gear 104, hollow output shaft 105, coupling 106; transmission mechanism 200, screw 201, screw nut 202, limit block 203, pull rod connecting shaft 204, spiral blade 205, windward surface 206, heat dissipation hole 207, conveying channel 208, transmission housing 209, sliding seat 210, double row angular contact ball bearing 211, anti-rotation pin 212, limit slide groove 213, bearing clamping ring 214, flange 215, end cover 216, graphite copper sleeve 217, limit baffle 218; clamp transmission assembly 300, pull rod 301, machine tool spindle 302, spindle mounting seat 303, machine tool platform 304; clamp 400. DETAILED DESCRIPTION

[0033] To facilitate understanding of the present invention, the present invention will be described more fully below with reference to the accompanying drawings.

[0034] It should be noted that when an element is considered to be "connected" to another element, it may be directly connected to the other element and integrated therewith, or there may be an intermediate element. The terms "mounted", "one end", "the other end" and similar expressions used herein are for illustrative purposes only.

[0035] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art. The terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0036] Please refer to Figures 3 to 6. The present invention provides a transmission mechanism 200, which includes a screw 201, a screw nut 202 and a pull rod connecting shaft 204; the screw 201 is provided with a power connection end for connecting to the power mechanism 100, and the screw 201 rotates under the drive of the power mechanism 100; the screw nut 202 is located in front of the power connection end, the screw nut 202 is sleeved on the outer periphery of the screw 201, the screw nut 202 and the screw 201 are matched through threads, and the screw nut 202 moves back and forth in the axial direction under the rotation of the screw 201; the pull rod connecting shaft 204 is located in front of the screw nut 202, and the pull rod connecting shaft 204 is connected to the screw nut 202. When the screw nut 202 moves axially, it drives the pull rod connecting shaft 204 to move axially, and the pull rod connecting shaft 204 is used to drive the clamping jaw transmission assembly 300 to move axially. The transmission mechanism 200 provided by the present invention can convert the rotation output of the power mechanism 100 such as the motor 101 into linear motion and output it to the clamping jaw transmission assembly 300 and the clamping jaw 400, thereby realizing the clamping action or opening action of the clamping jaw 400.

[0037] 3 , the present invention provides a first embodiment of a transmission mechanism 200. Preferably, the transmission mechanism 200 includes a lead screw 201, a lead screw nut 202, a pull rod connecting shaft 204, a spiral blade 205, a heat dissipation hole 207, a conveying channel 208, a transmission housing 209, a sliding seat 210, two double-row angular contact ball bearings 211, an anti-rotation pin 212, a limiting slide groove 213, four bearing clamping rings 214, a flange 215, an end cover 216, a graphite copper sleeve 217, a limiting baffle 218, and a flange 219. (219)

[0038] Screw 201 is a solid structure. Its outer side is connected to reducer 103, serving as the power input shaft. It rotates synchronously with reducer 103 to provide push / pull force. When the machine tool spindle 302 begins high-speed machining, screw 201 maintains its position and torque, rotating independently of spindle 302 to ensure that the push / pull force (i.e., the tooling jaws 400) remains constant.

[0039] The screw nut 202 is threadedly connected to the screw 201. When the screw 201 rotates, the nut can translate back and forth, and the two cooperate to convert the rotational motion into linear motion.

[0040] No. 1 double-row angular contact ball bearing 211: No. 1 double-row angular contact ball bearing 211 is arranged on the outer periphery of the screw 201 near the power connection end, and is used to position the screw 201 to ensure that the screw 201 can rotate freely and can withstand a large radial force.

[0041] The No. 2 double-row angular contact ball bearing 211 has its inner ring mounted on the pull rod connecting shaft 204 and its outer ring mounted on the inner wall of the sliding seat 210. It can provide radial rotation support during use and withstand the larger axial force brought by the pull rod 301 and the screw 201 at the same time.

[0042] The No. 1 bearing clamping ring 214 clamps and fixes the outer ring of the No. 1 double-row angular contact ball bearing 211 on one side of the screw 201.

[0043] The No. 2 bearing clamping ring 214 clamps and fixes the inner ring of the No. 1 double-row angular contact ball bearing 211 of the screw 201 to ensure that the installation position of the screw 201 and the bearing does not change.

[0044] Sliding seat 210 is fixedly connected to lead screw nut 202 by bolts and connected to tie rod connecting shaft 204 via a second double-row angular contact ball bearing 211. As the nut slides back and forth, it drives tie rod connecting shaft 204 back and forth simultaneously. One end of sliding seat 210 is sleeved over lead screw nut 202 and fixedly connected thereto; the other end of sliding seat 210 is sleeved over tie rod connecting shaft 204 and fixedly connected thereto. An anti-rotation pin 212 is also provided on the outer wall of sliding seat 210. This anti-rotation pin 212 cooperates with a limiting slot 213 to prevent sliding seat 210 from rotating, allowing sliding seat 210 to move back and forth along the axis driven by lead screw 201 and lead screw nut 202.

[0045] The transmission housing 209 has an inner wall surface provided with a limiting groove 213 which is concave radially outward. The limiting groove 213 extends axially, and the anti-rotation pin 212 is slidably connected in the limiting groove 213 at one end away from the outer wall of the sliding seat 210. The anti-rotation pin 212 can move forward and backward along the axial direction of the limiting groove 213, but the axis of the limiting groove 213 can prevent the anti-rotation pin 212 from rotating.

[0046] No. 1 graphite copper sleeve 217: close to the power connection end, sleeved on the outside of the sliding seat 210, providing support and lubrication for the sliding seat 210 to slide in the housing, reducing wear.

[0047] The second graphite copper sleeve 217 is away from the power connection end and is sleeved outside the other end of the sliding seat 210. Its function is the same as that of the first graphite copper sleeve 217 to provide support and lubrication to reduce wear.

[0048] The spiral blade 205 extends radially along the tie rod connecting shaft 204 (the installation direction of the spiral blade is axial insertion, and the radial direction is a tight fit). The spiral blade 205 is located inside the heat dissipation hole 207. When the lead screw 201 rotates, the spiral blade 205 is driven to rotate. In the conveying channel 208 within the connection between the shaft heat dissipation hole 207 and the tie rod 301, when the tie rod connecting shaft 204 rotates at high speed with the tie rod 301, the spiral blade 205 that follows the rotation will stir the air within its circulation space. Under the combined action of the through hole in the tie rod connecting shaft 204, the harmful heat generated by the wear between the internal parts is extracted and dissipated into the surrounding environment. The spiral blade 205 and the tie rod connecting shaft 204 have an interference fit, so that the spiral blade 205 is tightly fitted in the inner cavity of the tie rod connecting shaft 205.

[0049] The tie rod connecting shaft 204 is internally connected to the sliding seat 210 via a double-row angular contact ball bearing 211 and externally connected to the tie rod 301 via threads. During operation, the tie rod connecting shaft 204 must rotate at high speed with the tie rod 301 and simultaneously transmit the push / pull force generated by the lead screw 201 to the tie rod 301 for loosening or clamping the workpiece. The tie rod connecting shaft 204 is provided with a conveying channel 208 extending axially therethrough. Heat dissipation holes 207 are also provided radially along the tie rod connecting shaft 204, connecting the heat dissipation holes 207 to the cavity of the transmission housing 209 and the conveying channel 208, respectively. Helical blades 205 are provided on the outer wall of the lead screw 201, near the heat dissipation holes 207. As an output shaft, the tie rod connecting shaft 204 must rotate at high speed with the tie rod 301 during operation. For example, when the jaws 400 clamp a workpiece and begin rotating, the tie rod connecting shaft 204, due to its connection to the tie rod 301, rotates at high speed with the machine tool spindle 302.

[0050] The pull rod connecting shaft 204 of the present invention is internally connected to the sliding seat 210 via a double-row angular contact ball bearing 211 and externally connected to the pull rod 301, thereby achieving synchronous rotation and axial operation under high-tension working conditions. At the same time, an active heat dissipation structure is provided within (on) the shaft to ensure that harmful heat generated by internal friction during high-speed rotation can be effectively dissipated, avoiding internal overheating that may cause problems such as reduced workpiece strength or deterioration of lubricating oil. Furthermore, the lead screw 201 is connected to the reduction output shaft of the reducer. When the motor is not providing power, the lead screw 201 will be difficult to rotate under the action of external forces, achieving position self-locking. In addition, the housing of the power mechanism 100 also withstands the axial force transmitted through the bearings. At the same time, while the clamping jaws 400 clamp the workpiece and process it, the motor torque continuously outputs to maintain the torque required for the pull rod 301 to clamp the workpiece unchanged, thereby avoiding clamping failure caused by the lead screw nut 202 sliding back and forth due to the external force generated by the pull rod 301.

[0051] In the embodiment: The main function of the power mechanism 100 is to convert the rotational motion and torque output by the motor 101 into linear motion and torque, thereby realizing the conversion of the motion direction to achieve push-pull action. The use of high-precision double-row angular contact ball bearings 211 ensures that the power mechanism 100 can simultaneously withstand large axial and radial forces during high-speed rotation and workpiece clamping and loosening. The maximum speed of this type of bearing can reach 9000RPM to 11000RPM, so the power mechanism 100 is also suitable for scenarios where high-speed processing of workpieces is required, such as high-speed turning. The screw converts the rotational motion output by the motor 101 into linear motion; the motor 101 can be a servo motor or an ordinary motor; the sliding seat 210 is installed in the transmission housing 209 to receive the linear motion of the screw nut 202 and the pull rod connecting shaft 204, and can move linearly with the screw nut 202. One end of the pull rod connecting shaft 204 is connected to the sliding seat 210 through a double-row angular contact ball bearing 211, and the other end is connected to the pull rod 301, thereby realizing synchronous rotation and axial operation under high-tension working conditions. At the same time, an active heat dissipation structure is provided inside (on) the shaft to ensure that the harmful heat generated by internal friction during high-speed rotation can be effectively dissipated, avoiding internal overheating and causing problems such as reduced workpiece strength or deterioration of lubricating oil.

[0052] Please refer to Figures 4 and 6, the pull rod connecting shaft 204 realizes another embodiment of heat dissipation: the pull rod connecting shaft 204 of this embodiment is connected in the same manner and has the same function as the pull rod connecting shaft 204 in the previous embodiment, and the difference lies in the structure for generating air-cooling heat dissipation. The pull rod connecting shaft 204 of this embodiment is provided with a windward surface 206, and the windward surface 206 is located on the periphery of the heat dissipation through-hole 207. The windward surface 206 is in the shape of a groove, and is concave along the outer surface of the pull rod connecting shaft 204. Since the pull rod connecting shaft 204 is provided with multiple grooves on the outer surface of its shaft to form the windward surface 206, when the pull rod connecting shaft 204 rotates at high speed, the side walls of the grooves will stir the surrounding air head-on, and the pressurized air will enter the heat dissipation through-hole 207 and enter the conveying channel 208 of the shaft under the guidance of the windward surface 206, thereby causing gas flow to achieve air cooling and dissipation of harmful heat inside. Please refer to Figure 9. The heat dissipation hole 207 is a small hole for secondary air inlet. The heat dissipation hole is a stepped hole with a taper. The end of the heat dissipation hole close to the inner cavity of the pull rod connecting shaft 204 is smaller, and the end close to the windward surface 206 is larger. Cooperating with the windward surface 206 is more conducive to stirring the air and increasing the air entering the inner cavity of the pull rod connecting shaft 204.

[0053] Please refer to Figures 4 and 6. Compared with the transmission mechanism 200 in Figure 3, this embodiment provides another hollow screw 201 to realize the delivery channel 208 for conveying the cooling medium or workpiece to the clamping jaw 400. The difference and function of the solid and hollow screws 201: 1. Structural difference: The difference between the solid and hollow center screw 201 of the power mechanism 100. The solid structure means that the screw wire is a solid structure, and the screw nut 202 and the stroke limit block 203 adopt a bolt + baffle structure; the hollow structure means that the screw 201 is a hollow structure with a central hole, and the screw nut 202 and the stroke limit block 203 adopt an integrated baffle nut structure. Functional difference: The hollow structure can be connected to cooling water from the rear of the system and introduced into the workpiece clamping position from this structure, cooling the workpiece from the center during processing; as a processing feed port: for example, when the system is installed on a lathe, materials can be loaded and processed from the hollow screw wire structure. Specifically, the front end of the lead screw 201 is sleeved with the rear end of the pull rod connecting shaft 204, and the lead screw 201 and the pull rod connecting shaft 204 are coaxially arranged; the lead screw 201 and the pull rod connecting shaft 204 are respectively provided with a conveying channel 208, and the conveying channels 208 of the two are connected. The conveying channel 208 axially penetrates the front and rear ends of the lead screw 201, and the other conveying channel 208 axially penetrates the front and rear ends of the pull rod connecting shaft 204. The rear end of the pull rod connecting shaft 204 is sleeved on the front end of the lead screw 201. The lead screw 201 is located in front of the lead screw nut 202 and is also integrally provided with a limit block 203. The limit block 203 is raised compared to the outer peripheral wall of the lead screw 201, and the outer peripheral wall of the limit block 203 abuts against the pull rod connecting shaft 204; the limit block 203 limits the forward movement of the lead screw nut 202. Furthermore, the socket joint of the pull rod connecting shaft 204 and the lead screw 201 is kept sealed by the limit block 203 to ensure that the cooling water can be transported in the delivery channel 208. Of course, the two can also be sealed and rotatably connected by existing technologies. Generally speaking, a sealed connection is required when cooling water needs to pass through, but no water is required when spiral blades are provided in the middle. Furthermore, the lead screw 201 and the pull rod connecting shaft 204 are respectively provided with a delivery channel 208, and the delivery channels 208 of the two are connected; the jaw transmission assembly 300 includes a pull rod 301, the output end of the pull rod 301 is connected to the jaw 400, and the pull rod 301 is also provided with a delivery channel 208 along the axial direction, and the delivery channel 208 of the pull rod 301 is connected to the delivery channel 208 of the pull rod connecting shaft 204; the power mechanism 100 includes a motor 101 and a reducer 103, The input end of the reducer 103 and the output end of the motor 101 are respectively provided with an engaged input gear 104 and an output gear 102. The input end of the reducer 103 is a hollow output shaft 105, which runs through the body of the reducer 103. The front and rear ends of the hollow output shaft 105 protrude compared to the body of the reducer 103. The hollow output shaft 105 is connected to the conveying channel 208, and the hollow output shaft 105 can convey the cooling medium or workpiece into the conveying channel 208.

[0054] Referring to Figures 3-8, another aspect of the present invention provides an electric chuck, which further includes a power mechanism 100, a clamping jaw transmission assembly 300, a clamping jaw 400, and the transmission mechanism 200 described above. The output end of the power mechanism 100 is connected to the power connection end of the lead screw 201 of the transmission mechanism 200, and the power mechanism 100 drives the lead screw 201 to rotate. The input end of the clamping jaw transmission assembly 300 is connected to the pull rod connecting shaft 204 of the transmission mechanism 200, and the output end of the clamping jaw transmission assembly 300 is connected to the clamping jaw 400. The clamping jaw transmission assembly 300 moves in the axial direction under the drive of the pull rod connecting shaft 204, and the clamping jaw 400 performs a centripetal clamping action or an opening action under the drive of the clamping jaw transmission assembly 300. The clamping jaw 400 can include two left and right clamping jaws 400 and two up and down clamping jaws 400. The specific structure of the clamping jaw 400 is prior art and will not be described in detail. When in use, the two left-right clamping jaws 400 and the two up-down clamping jaws 400 respectively and synchronously clamp or release the workpiece from the left-right direction and the up-down direction.

[0055] Preferably, the power mechanism 100 includes a motor 101 and a reducer 103, the reducer 103 is located in front of the motor 101, the output end of the reducer 103 is connected to the connection end of the power of the screw 201, and the input end of the reducer 103 and the output end of the motor 101 are driven and connected by one of the following four methods: the input end of the reducer 103 and the output end of the motor 101 are respectively provided with an input gear 104 and an output gear 102, and the output gear 102 and the input gear 104 are meshed (please refer to Figure 7). Or the input end of the reducer 103 and the output end of the motor 101 are provided with a synchronous belt, and the two are driven and connected by the synchronous belt. Or the input end of the reducer 103 and the output end of the motor 101 are provided with a transmission belt, and the two are driven and connected by the transmission belt, for example, the input end of the reducer 103 and the output end of the motor 101 are respectively provided with pulleys, and the pulleys of the two are connected by a transmission belt. Alternatively, the input end of the reducer 103 and the output end of the motor 101 are connected via a coupling 106 (see FIG8 ); the coupling 106 is installed between the reducer 103 and the motor 101 , replacing the stacked gear structure.

[0056] Power mechanism 100: It is connected to the reducer 103 and the machine tool workpiece spindle at the front and rear respectively. It mainly converts the rotational motion and torque input by the motor 101 or the reducer 103 into linear motion and push-pull force, providing a power source for the pull rod 301 connected at the back. This structure serves as the core point.

[0057] Motor 101, a controllable forward and reverse motor, provides the power source for the entire system. In this example, a servo motor 101 is used. When motor 101 rotates forward, it drives rod 301 backward, clamping the workpiece. When motor 101 rotates reverse, rod 301 advances, releasing the workpiece. The motor 101 mounting base provides a foundation for motor 101 installation and is also connected to the transmission housing 209, forming a single, integral component. The output gear 102 is mounted on the rotating shaft of motor 101 and connects to the power input gear 104 on the reducer 103, providing power transmission. A protective cover fits over the power connection between motor 101 and reducer 103 and is bolted to the housing of the power mechanism 100, providing safety protection. The input gear 104, mounted on reducer 103, serves as the power input connection, receiving power from motor 101 and providing power input to reducer 103. The reducer 103 is mounted and fixed to the power mechanism 100. It reduces the power input from the motor 101, increases the torque, and transmits the power to the connected screw 201 of the power mechanism 100, providing power for the rotation of the screw 201. This embodiment uses an RV reducer 103, but other types of reducers 103, such as a planetary reducer 103, can also be used. When the torque requirement is low, such as for fragile workpieces or cutting conditions requiring low clamping force, the reducer structure can be omitted and the motor 101 can be directly connected to the power mechanism 100.

[0058] Pull rod 301: It can be movably inserted into the inner hole of the machine tool spindle 302, and its front and rear ends are respectively connected to the pull rod connecting shaft 204 of the transmission mechanism 200 and the clamping jaw 400 in the form of threads. The push / pull force of the pull rod connecting shaft 204 drives the pull rod 301 to move forward and backward in a straight line, thereby finally driving the clamping jaw 400 to clamp or release the workpiece.

[0059] The machine tool spindle 302 has an outer housing mounted within a spindle mounting base 303. One end of its internal rotating member is fixedly connected to a clamping jaw 400. Rotation of the rotating member drives the clamping jaw 400, allowing the clamping jaw 400 to rotate during workpiece machining, thereby enabling cutting. Alternatively, the clamping jaw 400 is connected to the tie rod 301, or the rotating member is connected to the tie rod 301, enabling the tie rod 301 to rotate, thereby driving the tie rod connecting shaft 204.

[0060] Machine tool platform 304: installed on the machine tool body, the platform is used to install the machine tool spindle 302.

[0061] Clamping jaw 400: mounted on the workpiece spindle, and can be linked with the pull rod 301 to clamp and release the workpiece.

[0062] In this application, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0063] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A transmission mechanism, characterized in that: The transmission mechanism includes a lead screw, a lead screw nut and a pull rod connecting shaft; the lead screw is used to connect with a power mechanism, and the lead screw rotates when driven by the power mechanism; the lead screw nut is located at the front end of the lead screw, and the lead screw nut cooperates with the lead screw through a thread, and the lead screw nut moves forward and backward in the axial direction when driven by the rotation of the lead screw; the pull rod connecting shaft is located in front of the lead screw nut, and the pull rod connecting shaft is connected to the lead screw nut, and when the lead screw nut moves axially, it drives the pull rod connecting shaft to move axially.

2. The transmission mechanism according to claim 1, characterized in that: The transmission mechanism also includes a transmission housing, the lead screw, lead screw nut and tie rod connecting shaft are arranged in the transmission housing, the tie rod connecting shaft is provided with a conveying channel running through it along the axial direction, and the tie rod connecting shaft is provided with heat dissipation holes along its radial direction, and the heat dissipation holes are respectively connected to the cavity of the transmission housing and the conveying channel.

3. The transmission mechanism according to claim 2, characterized in that: The outer side wall of the pull rod connecting shaft is provided with a windward surface, and the windward surface is located at the periphery of the heat dissipation through hole; or A spiral blade is arranged on the outer side wall of the pull rod connecting shaft near the heat dissipation through hole. The spiral blade extends radially along the pull rod connecting shaft and is located inside the heat dissipation through hole. When the pull rod connecting shaft rotates, the spiral blade is driven to rotate.

4. The transmission mechanism according to claim 1, characterized in that: The front end of the lead screw is sleeved with the rear end of the pull rod connecting shaft, and the lead screw and the pull rod connecting shaft are coaxially arranged; the lead screw and the pull rod connecting shaft are respectively provided with conveying channels, and the conveying channels of the two are connected, and the conveying channel axially penetrates the front and rear ends of the lead screw, and the other conveying channel axially penetrates the front and rear ends of the pull rod connecting shaft.

5. The transmission mechanism according to claim 1, characterized in that: The rear end of the pull rod connecting shaft is sleeved on the front end of the screw. The screw is also integrally provided with a limit block in front of the screw nut. The limit block is raised compared to the outer peripheral wall of the screw. The limit block limits the forward movement of the screw nut.

6. The transmission mechanism according to claim 1, characterized in that: The transmission mechanism also includes a transmission housing, a sliding seat and a graphite copper sleeve, the sliding seat and the graphite copper sleeve are arranged in the transmission housing, the graphite copper sleeve is arranged outside the sliding seat, and the outer wall of the graphite copper sleeve is slidably connected to the transmission housing; one end of the sliding seat sleeve is sleeved outside the screw nut and fixedly connected to the screw nut; the other end of the sliding seat sleeve is sleeved outside the pull rod connecting shaft and fixedly connected to the pull rod connecting shaft; a limiting groove concave radially outward is provided on the inner wall surface of the transmission housing, and the limiting groove extends axially; an anti-rotation pin is also provided on the outer wall of the sliding seat sleeve, and the end of the anti-rotation pin away from the outer wall of the sliding seat sleeve is slidably connected in the limiting groove.

7. The transmission mechanism according to claim 6, characterized in that: The transmission mechanism also includes two double-row angular contact ball bearings; the inner ring of one of the double-row angular contact ball bearings is connected to the outer circumferential wall of the screw near the power connection end, and its outer ring is fixedly connected to the inner circumferential wall of the transmission housing; the inner ring of the other double-row angular contact ball bearing is sleeved on the pull rod connecting shaft, and its outer ring is installed on the inner circumferential wall of the sliding seat.

8. An electric chuck, characterized in that: The electric chuck also includes a power mechanism, a jaw transmission assembly, a jaw and a transmission mechanism as described in any one of claims 1 to 7; the output end of the power mechanism is connected to the screw power connection end of the transmission mechanism, and the power mechanism drives the screw to rotate; the input end of the jaw transmission assembly is connected to the pull rod connecting shaft of the transmission mechanism, and the output end of the jaw transmission assembly is connected to the jaw, and the jaw transmission assembly moves in an axial direction driven by the pull rod connecting shaft, and the jaw performs a centripetal clamping action or an opening action driven by the jaw transmission assembly.

9. The electric chuck according to claim 8, characterized in that: The power mechanism includes a motor and a reducer, wherein the reducer is located in front of the motor, the output end of the reducer is connected to the connection end of the screw power, and the input end of the reducer is connected to the output end of the motor through one of the following driving connections: The input end of the reducer and the output end of the motor are respectively provided with an input gear and an output gear, and the output gear is meshed with the input gear; or the input end of the reducer and the output end of the motor are provided with a synchronous belt; Alternatively, a transmission belt is provided at the input end of the reducer and the output end of the motor; or the input end of the reducer and the output end of the motor are connected via a coupling.

10. The electric chuck according to claim 9, characterized in that: The lead screw and the pull rod connecting shaft are respectively provided with conveying channels, and the conveying channels of the two are connected; the clamp transmission assembly includes a pull rod, the output end of the pull rod is connected to the clamp, and the pull rod is also provided with a conveying channel along the axial direction, and the conveying channel of the pull rod is connected with the conveying channel of the pull rod connecting shaft; the power mechanism includes a motor and a reducer; the input end of the reducer and the output end of the motor are respectively provided with meshing input gears and output gears, or the input end of the reducer and the output end of the motor are respectively provided with pulleys, and the pulleys of the two are connected by a transmission belt; the input end of the reducer is a hollow output shaft, and the hollow output shaft passes through the reducer body, and the front and rear ends of the hollow output shaft protrude compared to the reducer body, and the hollow output shaft is connected with the conveying channel, and the hollow output shaft can convey the cooling medium or the workpiece into the conveying channel, and the conveying channel conveys the cooling medium or the workpiece to the clamp.

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