A Y-axis transmission mechanism of a gantry coordinate measuring machine

Abstract

The present invention discloses a Y-axis transmission mechanism of a gantry three-dimensional coordinate measuring machine, which relates to the technical field of gantry three-dimensional coordinate measuring machines. The Y-axis transmission mechanism includes a main shoulder, a Y-axis guide rail, and a Y-axis rack. The Y-axis rack is arranged on the top surface of the Y-axis guide rail along the extension direction of the Y-axis guide rail; a transmission assembly, which includes: a gear reduction plate, including a main gear seat installed on the main shoulder, a main gear matched in the main gear seat, an anti-backlash gear provided in a fixed sleeve in the main gear, the main gear and the anti-backlash gear are both engaged with the Y-axis rack, and a reduction plate is connected to the main gear; the motor and the reduction plate are connected by a belt, and the motor is used to drive the reduction plate to rotate. This application can improve the structural rigidity and stability, improve the carrying capacity of the measuring machine, resist load, reduce vibration effects, and improve transmission accuracy and stability by rationally designing the support point distribution of the main shoulder of the gantry structure, the Y-axis guide rail layout, and the transmission assembly layout.

Description

Technical Field

[0001] The present invention relates to the technical field of gantry three-coordinate measuring machines, and in particular to a Y-axis transmission mechanism of a gantry three-coordinate measuring machine. Background Art

[0002] A gantry-type coordinate measuring machine (CMM) is a highly efficient measuring device based on precision mechanics, optics, and computer technology. It is primarily used for inspecting the geometry and dimensions of large workpieces, such as automotive bodies, molds, and aerospace components. Its fixed gantry structure enhances overall rigidity and stability, while its granite base further enhances deformation resistance and measurement accuracy. Utilizing a three-axis linkage system and digital acquisition technology, gantry-type CMMs achieve micron-level precision in three-dimensional measurements, making them a key alternative to traditional tools. They are widely used in machinery manufacturing, electronics, mold development, and other fields, particularly in reverse engineering and quality inspection, such as scanning complex structures like gears and engine cases.

[0003] Since the gantry-type drive system is on one side, the Abbe error is more obvious, which may affect the transmission accuracy. The Abbe error is the error caused by the misalignment of the measuring line and the reference line. When the gantry-type drive system is driven, the motion trajectory of the worktable and the guide rail are easily inconsistent. The yaw angle error will amplify the Abbe error, especially in long-stroke processing. The cumulative error effect is more significant, causing the worktable to deviate from the predetermined motion trajectory, resulting in straightness errors in workpiece processing. In addition, the inertia of large gantry structures is large, which may lead to unstable drive, especially during high-speed measurement. Vibration is prone to occur. Traditional gantry drives cause uneven force on the gantry structure and low load-bearing capacity. It is difficult to ensure the accuracy of the long-stroke gantry structure, and it is unable to effectively resist the load and reduce the impact of vibration. Under the action of load and vibration, the accuracy will be greatly reduced. Summary of the Invention

[0004] The object of the present invention is to provide a Y-axis transmission mechanism for a gantry coordinate measuring machine, which can improve the carrying capacity and transmission accuracy of the measuring machine.

[0005] To this end, the present invention provides a Y-axis transmission mechanism of a gantry coordinate measuring machine, including a main shoulder and a Y-guide rail, and also including: a Y-axis rack, which is arranged on the top surface of the Y-guide rail along the extension direction of the Y-guide rail; a transmission assembly, a gear reduction plate, including a main gear seat installed on the main shoulder, a main gear being matched with a main gear in the main gear seat, an anti-backlash gear being provided in a fixed sleeve in the main gear, the main gear and the anti-backlash gear both being meshed with the Y-axis rack, and a reduction plate being connected to the main gear; a motor, the motor and the reduction plate being connected by a belt, the motor being used to drive the reduction plate to rotate; the main gear and the anti-backlash gear are driven to rotate along the Y-axis rack by the rotation of the reduction plate, so as to drive the main shoulder to move along the Y-guide rail.

[0006] Preferably, the main shoulder includes a first main shoulder portion, which is arranged on the top surface of the Y-guide rail along the extension direction of the Y-guide rail, and the width of the first main shoulder portion is smaller than the width of the Y-guide rail; the Y-axis rack is located on one side of the first main shoulder portion and is parallel to the first main shoulder portion; the transmission assembly is installed on one side of the first main shoulder and is located above the Y-axis rack.

[0007] Preferably, second main shoulders are symmetrically provided at both ends of the first main shoulder, and the width of the first main shoulder is smaller than that of the second main shoulder; a first air bearing is provided at the bottom of the second main shoulder, and the first air bearing corresponds to the top surface of the Y-guide rail; second air bearings are respectively provided at both ends of the second main shoulder, and the second air bearings correspond to the side surfaces of the Y-guide rail.

[0008] Preferably, the transmission assembly includes a main shoulder mounting seat installed on the main shoulder, the main shoulder mounting seat is provided with a groove, and a reducer mounting plate is provided in the groove; corresponding through holes are provided on the reducer mounting plate and the groove, the main gear seat is fitted in the through hole, and the main gear seat and the reducer mounting plate are connected by bolts.

[0009] Preferably, the reducer mounting plate is installed in the groove by means of a top screw, and the rack clearance between the main gear and the Y-axis rack is adjusted by rotating the top screw.

[0010] Preferably, a bearing is installed in the main gear seat, and the main gear is matched with the inner ring of the bearing.

[0011] Preferably, the anti-backlash gear is located at the top of the main gear, the inner shaft of the anti-backlash gear extends into the main gear, and the inner shaft of the anti-backlash gear and the main gear both extend out of the main gear seat and are fixedly connected.

[0012] Preferably, a pressing seat is connected to the main gear, and the reduction plate is fixedly sleeved on the outside of the pressing seat.

[0013] Preferably, the motor is mounted on the main shoulder mounting seat via a motor mounting seat, and the motor mounting seat includes an opening facing the gear reduction plate, and the opening is used to avoid the belt.

[0014] Preferably, a stretching plate is provided on the main shoulder mounting seat, and a stretching bolt is connected between the stretching plate and the motor mounting seat.

[0015] Compared with the prior art, the advantages and positive effects of the present invention are:

[0016] The main shoulder of the present application presents an overall U-shaped structure. This design of the main shoulder structure not only concentrates the center of gravity between the first air bearing of the main shoulder, but also leaves a larger space for installing the transmission assembly. This makes the Y-axis transmission mechanism of the gantry coordinate measuring machine compact and occupies a small space, which is beneficial to the overall layout and design of the gantry coordinate measuring machine. By rationally designing the support point distribution of the main shoulder of the gantry structure, the Y-axis guide rail layout, and the transmission assembly layout, the present application can improve the structural rigidity and stability, improve the load-bearing capacity of the measuring machine, resist load, reduce the impact of vibration, and improve transmission accuracy and stability.

[0017] The anti-backlash gears of this application can effectively reduce backlash, alleviating impact and vibration during the meshing process of the main gear. This makes the main gear transmission more precise and stable, improving the machining accuracy or motion control precision of the equipment. In systems such as coordinate measuring machines that require fast response and precise control, anti-backlash gears can also reduce hysteresis caused by backlash, allowing the driven gear to more quickly follow the movement of the driving gear, thereby improving the system's response speed and dynamic performance.

[0018] Compared to other transmission methods, the rack drive used in this application is simpler and more compact, taking up less space and facilitating the overall layout and design of a gantry-type CMM. For large gantry-type CMMs requiring a longer travel, rack drives can achieve this by connecting the two ends together, meeting the measurement range requirements of the equipment.

[0019] Other features and advantages of the present invention will become more apparent after reading the detailed description of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is one of the structural schematic diagrams of an embodiment of the Y-axis transmission mechanism of the gantry coordinate measuring machine of the present invention;

[0021] Figure 2 This is one of the structural diagrams of an embodiment of the main shoulder of the present invention;

[0022] Figure 3 This is a second structural diagram of an embodiment of the main shoulder of the present invention;

[0023] Figure 4 This is a second structural diagram of an embodiment of the Y-axis transmission mechanism of the gantry coordinate measuring machine of the present invention;

[0024] Figure 5 This is a third structural diagram of an embodiment of the Y-axis transmission mechanism of the gantry coordinate measuring machine of the present invention;

[0025] Figure 6 This is one of the cross-sectional schematic diagrams of an embodiment of the Y-axis transmission mechanism of the gantry coordinate measuring machine of the present invention;

[0026] Figure 7 This is a second cross-sectional schematic diagram of an embodiment of the Y-axis transmission mechanism of the gantry coordinate measuring machine of the present invention;

[0027] Description of reference numerals:

[0028] 10. Main shoulder; 11. First main shoulder; 12. Second main shoulder; 13. First air bearing; 14. Second air bearing; 15. Crossbeam contact finish surface; 16. Measurement finish surface; 17. Transmission finish surface;

[0029] 20. Y guide rail;

[0030] 30. Y-axis rack;

[0031] 41. Main gear seat; 42. Bearing; 43. Main gear; 44. Anti-backlash gear; 45. Pressing seat; 46. Pressing plate; 47. Speed ​​reducer;

[0032] 50. Motor; 51. Belt; 52. Motor mounting base;

[0033] 61. Vertical mounting plate; 62. Horizontal mounting plate; 63. Reducer mounting plate; 64. Tensile plate; 65. Tensile bolt. DETAILED DESCRIPTION

[0034] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0035] like Figure 1-Figure 7 As shown, the present application provides a Y-axis transmission mechanism of a gantry coordinate measuring machine, comprising a main shoulder 10, a Y-axis guide rail 20, a Y-axis rack 30 and a transmission assembly, wherein the transmission assembly is used to drive the main shoulder 10 to move linearly along the Y-axis guide rail 20.

[0036] The main shoulder 10 is an integral part and includes a first main shoulder portion 11 . The first main shoulder portion 11 is arranged on the top surface of the Y guide rail 20 along the extension direction of the Y guide rail 20 . The width of the first main shoulder portion 11 is smaller than the width of the Y guide rail 20 .

[0037] Second main shoulders 12 are symmetrically provided at both ends of the first main shoulder 11, and the width of the first main shoulder 11 is smaller than that of the second main shoulder 12; two first air bearings 13 are provided at the bottom of the second main shoulder 12, and the two first air bearings 13 are respectively located at the two ends of the bottom of the second main shoulder 12, and the first air bearings 13 correspond to the top surface of the Y-guide rail 20; second air bearings 14 are respectively provided at both ends of the second main shoulder 12, and the second air bearings 14 correspond to the side surfaces of the Y-guide rail 20.

[0038] The Y-axis rack 30 is arranged on the top surface of the Y-axis guide rail 20 along the extension direction of the Y-axis guide rail 20. The Y-axis rack 30 is located on one side of the first main shoulder 11 and is parallel to the first main shoulder 11; the transmission assembly is installed on one side of the first main shoulder 11 and is located above the Y-axis rack 30.

[0039] The main shoulder 10 of the present application presents an overall U-shaped structure. This design of the main shoulder 10 not only concentrates the center of gravity between the first air bearing 13 of the main shoulder 10, but also leaves a larger space for installing the transmission assembly. This makes the Y-axis transmission mechanism of the gantry coordinate measuring machine compact and occupies a small space, which is beneficial to the overall layout and design of the gantry coordinate measuring machine. By rationally designing the support point distribution of the main shoulder 10 of the gantry structure, the layout of the Y-axis guide rail 20, and the layout of the transmission assembly, the present application can improve the structural rigidity and stability, enhance the load-bearing capacity of the measuring machine, resist load, reduce the impact of vibration, and improve transmission accuracy and stability.

[0040] The main shoulder 10 of the present application is entirely made by a casting process, and the middle part is a reinforced hollow structure, which greatly reduces the weight of the main shoulder 10.

[0041] The first main shoulder 11 has three finish-machined surfaces to ensure machining accuracy. The top surface of the first main shoulder 11 is provided with a parallel beam contact finish surface 15 and a measuring finish surface 16. The beam contact finish surface 15 is higher than the measuring finish surface 16. The beam contact finish surface 15 ensures the connection accuracy between the main shoulder 10 and the beam. During the air bearing installation process, the installation accuracy of the air bearing can be guaranteed by placing a spirit level on the measuring finish surface 16. The side of the first main shoulder 11 is provided with a transmission finish surface 17. The transmission finish surface 17 is perpendicular to the beam contact finish surface 15 and is in close contact with the finish surface of the main shoulder mounting seat, ensuring that the finish surface of the main shoulder mounting seat and the transmission finish surface 17 are completely in close contact with each other.

[0042] like Figure 4-Figure 7As shown, the transmission assembly includes a gear reduction plate and a motor 50 .

[0043] The gear reduction plate includes a main gear seat 41 , in which a bearing 42 is installed. The main gear seat 41 and the bearing 42 are interference fit; the inner ring of the bearing 42 is fitted with a main gear 43 , and the main gear 43 can rotate freely around the bearing 42 .

[0044] The number of bearings 42 can be two, and the two bearings 42 are symmetrically arranged in the main gear seat 41; by setting two bearings 42, the main gear 43 can be guaranteed to rotate freely and stably and effectively, thereby ensuring effective transmission and improving transmission stability.

[0045] The gear reduction plate further includes an anti-backlash gear 44 , which is located at the bottom of the main gear 43 . The anti-backlash gear 44 and the main gear 43 are both engaged with the Y-axis rack 30 .

[0046] The anti-backlash gear 44 is provided with an inner shaft (not shown in the figure), and the inner shaft and the anti-backlash gear 44 are fixed as an integral part. The inner shaft of the anti-backlash gear 44 extends into the main gear 43, and the inner shaft of the anti-backlash gear 44 and the main gear 43 both extend out of the main gear seat 41 and are fixedly connected; the inner shaft of the anti-backlash gear 44 and the main gear 43 can be fixedly connected by a screw locking device, and no specific restrictions are made here.

[0047] A pressing seat 45 is sleeved and connected to the main gear 43 . The pressing seat 45 can be connected to the main gear 43 through a pressing piece 46 and screws, so that the pressing seat 45 and the main gear 43 are connected as a whole.

[0048] A speed reduction disc 47 is fixedly sleeved on the pressing seat 45 . The speed reduction disc 47 and the pressing seat 45 can be fixed together by screws, which is not specifically limited here.

[0049] The output shaft of the motor 50 and the reduction plate 47 are connected by a belt 51, and the motor 50 is used to drive the reduction plate 47 to rotate; the rotation of the reduction plate 47 can drive the main gear 43 and the anti-backlash gear 44 to move along the Y-direction rack 30, thereby driving the main shoulder 10 to move along the Y-direction guide rail 20.

[0050] The transmission assembly includes a main shoulder mounting seat, which is an L-shaped integral part. The main shoulder mounting seat includes a vertical mounting plate 61 and a horizontal mounting plate 62; the vertical mounting plate 61 is fitly connected to the transmission finishing surface 17 of the main shoulder 10, and the connection method can be a bolted fixed connection, which is not specifically limited here.

[0051] The transverse mounting plate 62 has a groove, within which the reducer mounting plate 63 is located. The reducer mounting plate 63 and the groove have corresponding through-holes, into which the main gear seat 41 fits. Bolts connect the main gear seat 41 and the reducer mounting plate 63. The main gear 43 and the anti-backlash gear 44 extend into the bottom of the transverse mounting plate 62 and mesh with the Y-axis rack 30.

[0052] The reducer mounting plate 63 is installed in the groove by means of a top screw. By rotating the top screw, the distance between the reducer mounting plate 63 and the Y-axis rack 30 can be adjusted, thereby adjusting the rack clearance between the main gear 43 and the anti-backlash gear 44 and the Y-axis rack 30, making the transmission of the main gear 43 more precise and smooth.

[0053] The motor 50 is mounted on the transverse mounting plate 62 via a motor mounting seat 52 . The motor mounting seat 52 includes an opening facing the gear reduction plate, and the opening is used to avoid the belt 51 .

[0054] A tension plate 64 is provided on the transverse mounting plate 62, and a tension bolt 65 is connected between the tension plate 64 and the motor mounting base 52. By rotating the tension bolt 65, the distance between the motor 50 and the gear reduction plate can be adjusted, thereby adjusting the tension of the belt 51, so that the belt 51 can play an effective transmission role.

[0055] The existence of gear clearance during gear transmission can cause idle travel in the gears, that is, the driving wheel rotates while the driven wheel has not yet started to rotate, which affects the accuracy and stability of the transmission. The anti-backlash gear 44 of the present application can effectively reduce the side clearance, reduce the impact and vibration of the main gear 43 during the meshing process, make the transmission of the main gear 43 more precise and smooth, and improve the processing accuracy or motion control accuracy of the equipment. In a system such as a three-dimensional coordinate measuring machine that requires fast response and precise control, the anti-backlash gear 44 can also reduce the hysteresis caused by the side clearance, so that the driven wheel can follow the movement of the driving wheel more quickly, thereby improving the response speed and dynamic performance of the system.

[0056] In the gantry coordinate measuring machine of the present application, the Y-axis rack 30 is installed parallel to the xy plane (the top surface of the Y-axis guide rail 20), and the auxiliary shoulder rack is installed perpendicular to the xy plane, which has the following advantages:

[0057] (1) Improve motion accuracy and stability

[0058] When the Y-axis rack 30 is mounted parallel to the xy plane, it provides stable and precise guidance for the gantry machine's movement within the xy plane. For large-span gantry machines, xy plane motion requires high positioning accuracy. A parallel mounting of the Y-axis rack 30 ensures smoother drive and reduces machining errors caused by motion deviation.

[0059] Vertically mounted auxiliary shoulder rack: Mounting the auxiliary shoulder rack perpendicular to the xy plane enhances the gantry machine's stability in the z-direction. When a large-span gantry machine is moving in the z-axis, the vertically mounted auxiliary shoulder rack can better withstand axial forces and torque, preventing the gantry structure from tilting or shaking in the vertical direction, and ensuring the accuracy and stability of the z-axis motion during machining.

[0060] (2) Enhanced carrying capacity

[0061] The Y-axis rack 30, which is parallel to the xy plane, effectively distributes the load, ensuring uniform force distribution across the entire gantry structure. Large-span gantry machines often experience significant cutting forces and workpiece weight when machining large workpieces. The parallel Y-axis rack 30 evenly distributes these loads throughout the entire drive system, preventing component damage caused by localized excessive force and improving the gantry machine's overall load-bearing capacity.

[0062] The auxiliary shoulder rack perpendicular to the xy plane helps to improve the gantry machine's load-bearing capacity in the vertical direction. When performing heavy cutting or processing large and heavy workpieces, the vertically installed auxiliary shoulder rack can effectively support the gantry structure and prevent it from deformation due to gravity, thereby ensuring the gantry machine's load-bearing capacity and stability in the z-axis direction.

[0063] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for a person skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to replace some of the technical features therein with equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions claimed to be protected by the present invention.

Claims

1. A Y-axis transmission mechanism of a gantry coordinate measuring machine, comprising a main shoulder and a Y-axis guide rail, characterized in that: Also includes: A Y-axis rack, arranged on the top surface of the Y-axis guide rail along the extension direction of the Y-axis guide rail; A transmission assembly comprising: A gear reduction plate, comprising a main gear seat mounted on the main shoulder, a main gear fitted in the main gear seat, an anti-backlash gear provided in a fixed sleeve within the main gear, both the main gear and the anti-backlash gear meshing with the Y-axis rack, and a reduction plate connected to the main gear; A motor, wherein the motor and the reduction plate are connected via a belt, and the motor is used to drive the reduction plate to rotate; the rotation of the reduction plate drives the main gear and the anti-backlash gear to rotate along the Y-direction belt, thereby driving the main shoulder to move along the Y-direction guide rail; The main shoulder includes a first main shoulder portion, the first main shoulder portion is arranged on the top surface of the Y guide rail along the extension direction of the Y guide rail, and the width of the first main shoulder portion is smaller than the width of the Y guide rail; The Y-axis rack is located on one side of the first main shoulder and is parallel to the first main shoulder; Second main shoulders are symmetrically provided at both ends of the first main shoulder, and the width of the first main shoulder is smaller than the width of the second main shoulder; A first air bearing is provided at the bottom of the second main shoulder, and two first air bearings are respectively located at two ends of the bottom of the second main shoulder, and the first air bearings correspond to the top surface of the Y-guide rail; A second air bearing is provided at each end of the second main shoulder, and the second air bearing corresponds to the side surface of the Y-guide rail; The transmission assembly is mounted on one side of the first main shoulder and above the Y-axis rack between the two second main shoulders; The main shoulder is generally U-shaped. This design of the main shoulder structure can concentrate the center of gravity between the first air bearings of the main shoulder and leave a larger space for installing the transmission assembly. The transmission assembly includes a main shoulder mounting seat installed on the main shoulder, the first main shoulder has three finish-machined surfaces to ensure processing accuracy, the top surface of the first main shoulder is provided with a parallel beam contact finish surface and a measurement finish surface, the beam contact finish surface is higher than the measurement finish surface; the function of the beam contact finish surface is to ensure the connection accuracy between the main shoulder and the beam; during the installation of the air bearing, the installation accuracy of the air bearing can be ensured by placing a spirit level on the measurement finish surface; the side of the first main shoulder is provided with a transmission finish surface, the transmission finish surface is perpendicular to the beam contact finish surface, and the transmission finish surface is fit-fitted and connected to the finish surface of the main shoulder mounting seat, ensuring that the finish surface of the main shoulder mounting seat is completely fit-fitted and connected to the transmission finish surface.

2. The Y-axis transmission mechanism of the gantry coordinate measuring machine according to claim 1, characterized in that: A groove is provided on the main shoulder mounting seat, and a reducer mounting plate is provided in the groove; corresponding through holes are provided on the reducer mounting plate and the groove, and the main gear seat is fitted in the through holes, and the main gear seat and the reducer mounting plate are connected by bolts.

3. The Y-axis transmission mechanism of the gantry coordinate measuring machine according to claim 2, characterized in that: The reducer mounting plate is installed in the groove through a top screw, and the rack gap between the main gear and the Y-axis rack is adjusted by rotating the top screw.

4. The Y-axis transmission mechanism of the gantry coordinate measuring machine according to claim 1, characterized in that: A bearing is installed in the main gear seat, and the main gear is matched with the inner ring of the bearing.

5. The Y-axis transmission mechanism of the gantry coordinate measuring machine according to claim 1, characterized in that: The anti-backlash gear is located on the top of the main gear, the inner shaft of the anti-backlash gear extends into the main gear, and the inner shaft of the anti-backlash gear and the main gear both extend out of the main gear seat and are fixedly connected.

6. The Y-axis transmission mechanism of the gantry coordinate measuring machine according to claim 1, characterized in that: The main gear is connected with a pressing seat, and the reduction plate is fixedly sleeved on the outside of the pressing seat.

7. The Y-axis transmission mechanism of the gantry coordinate measuring machine according to claim 2, characterized in that: The motor is mounted on the main shoulder mounting seat through a motor mounting seat, The motor mounting seat includes an opening facing the gear reduction plate, and the opening is used to avoid the belt.

8. The Y-axis transmission mechanism of the gantry coordinate measuring machine according to claim 7, characterized in that: A stretching plate is provided on the main shoulder mounting seat, and a stretching bolt is connected between the stretching plate and the motor mounting seat.

Images