X-axis driving structure

Abstract

The utility model relates to an X-axis driving structure which comprises a cross beam, a sliding block which is provided with a measuring head and is arranged on the cross beam in a mode of sliding along a specific direction, a grating ruler and a plurality of linear guide rails which are arranged on the cross beam along the specific direction, each linear guide rail comprises a guide rail assembly and a plurality of sliding block assemblies, and the guide rail assemblies are fixedly arranged on the cross beam. The sliding block assembly is fixedly connected with the sliding block, the multiple linear guide rails comprise the first linear guide rail arranged on the first installation face of the cross beam and the second linear guide rail arranged on the second installation face of the cross beam, and the first installation face and the second installation face are perpendicular to the specific direction. A non-zero included angle is formed between the first installation face and the second installation face so that the sliding block assembly of the first linear guide rail and the sliding block assembly of the second linear guide rail can have different postures, and the grating ruler is arranged on the cross beam in the specific direction and used for measuring the position of the sliding block on the cross beam. Therefore, the movement stability of the sliding block can be improved.

Description

Technical Field

[0001] This utility model relates to the field of intelligent manufacturing equipment industry, specifically to an X-axis drive structure. Background Technology

[0002] Measuring instruments generally include a probe, a motion system, and a measuring platform. The probe can be an optical probe or a contact probe, used to acquire geometric quantities such as the shape, surface profile, or height of the measurement point on the workpiece on the measuring platform. The motion system typically includes multiple X-axis drive structures corresponding to different directions, thereby controlling the movement of the probe or measuring platform in different directions. For example, the motion system may include X-axis drive structures, Y-axis drive structures, and Z-axis drive structures, controlling the relative movement of the probe and measuring platform in the X, Y, and Z directions, respectively.

[0003] The accuracy and repeatability of measuring instruments are related to multiple factors, including but not limited to temperature changes, mechanical deformation, excessive running time, or algorithm defects. Therefore, even if deviations in measurement results are found, extensive experiments are needed to identify the problem and propose appropriate solutions. However, for complex measuring instruments, it is not only difficult to pinpoint the problem but also to determine a suitable solution. Furthermore, the problem points often differ depending on the application scenario, manufacturer, and model of the measuring instrument, making it difficult to directly obtain effective solutions from existing technologies. Summary of the Invention

[0004] This invention was made in view of the above circumstances, and its purpose is to provide an X-axis drive structure that can improve the motion stability of the slider.

[0005] To address this, the present invention provides an X-axis drive structure, comprising a crossbeam, a slider mounted on the crossbeam with the probe and slidable along a specific direction, an optical encoder, and multiple linear guides mounted on the crossbeam along the specific direction. Each linear guide includes a guide rail assembly and multiple slider assemblies. The guide rail assembly is fixedly mounted on the crossbeam, and the slider assembly is fixedly connected to the slider. Each linear guide includes a first linear guide with a first mounting surface on the crossbeam and a second linear guide with a second mounting surface on the crossbeam. The first mounting surface and the second mounting surface are perpendicular to the specific direction, and the first mounting surface and the second mounting surface have a non-zero angle so that the slider assembly of the first linear guide and the slider assembly of the second linear guide have different orientations. The optical encoder is mounted on the crossbeam along the specific direction and is used to measure the position of the slider on the crossbeam.

[0006] Because existing linear guides consist of a guide rail assembly and a sliding assembly that mates with it, the guide rail assembly and the sliding assembly slide together, and the sliding assembly's encirclement of the guide rail assembly ensures high linearity of motion for the sliding assembly. Therefore, even using only one linear guide can theoretically guarantee the linearity of the slider's motion. However, in measuring instruments with probes, the probe itself is heavy, which can easily affect the linearity of the slider's motion. In this case, multiple linear guides can be arranged simultaneously to improve the linearity of the slider's motion through a homogenization effect. Furthermore, if multiple linear guides are arranged on the same plane, there is still a large degree of rotational freedom in some directions. In this case, the mounting surfaces of the multiple linear guides can be angled to fully utilize the rotational freedom of the linear guides in various directions, thereby further limiting the slider's rotation.

[0007] Furthermore, in the X-axis drive structure of this utility model, optionally, the grating ruler includes a grating ruler fixing plate, a grating, and a reading head. The grating is disposed on the crossbeam along the specific direction via the grating ruler fixing plate, and the reading head is disposed on the slider. The grating ruler fixing plate protrudes from the surface of the slider toward the probe, and the grating is disposed on the portion of the grating ruler fixing plate protruding from the surface of the slider toward the probe. In this case, disposing of the grating on the portion of the grating ruler fixing plate protruding from the surface of the slider toward the probe effectively reduces the distance between the grating and the crossbeam and the probe (or the object to be measured). Since the length measurement structure is angle-dependent, the shorter the distance between the grating and the crossbeam and the probe (or the object to be measured), the smaller the influence, thereby improving accuracy.

[0008] Alternatively, in the X-axis drive structure of this invention, the grating ruler fixing plate can be disposed at the bottom of the crossbeam, the grating can be disposed at the bottom of the grating ruler fixing plate, and the reading head can be disposed at the bottom of the slider. In this case, the grating and the reading head can cooperate to measure the position of the slider on the crossbeam.

[0009] Furthermore, in the X-axis drive structure of this invention, optionally, the first mounting surface is the top surface of the crossbeam, and the second mounting surface is the front surface of the crossbeam. In this case, the slider assembly of the first linear guide and the slider assembly of the second linear guide can have different postures based on the shape of the crossbeam.

[0010] In addition, in the X-axis drive structure involved in this utility model, the included angle between the first mounting surface and the second mounting surface may optionally be 30°, 45°, 60° or 90°.

[0011] Furthermore, in the X-axis drive structure of this invention, optionally, the multiple slider assemblies include two slider assemblies respectively disposed on both sides of the slider, and the distance between the two slider assemblies is not less than 50 mm. This allows for a larger span, thereby improving the motion stability of the slider.

[0012] In addition, in the X-axis drive structure involved in this utility model, optionally, the motion system controls the probe to move in the X-axis direction and the Z-axis direction, and controls the platform to move in the Y-axis direction.

[0013] In addition, in the X-axis drive structure involved in this utility model, the X-axis drive structure optionally includes a transmission mechanism mounted on the crossbeam. The transmission mechanism is a lead screw drive, belt drive or synchronous belt drive, and the transmission mechanism is used to drive the slider to move along the specific direction.

[0014] In addition, in the X-axis drive structure involved in this utility model, optionally, the transmission mechanism is located between the first linear guide rail and the second linear guide rail.

[0015] In addition, in the X-axis drive structure involved in this utility model, optionally, the flatness of the first mounting surface and the second mounting surface is not greater than 10 micrometers.

[0016] According to this utility model, an X-axis drive structure that can improve the motion stability of the slider can be provided. Attached Figure Description

[0017] The present invention will now be explained in further detail by way of example only with reference to the accompanying drawings.

[0018] Figure 1 This is a three-dimensional schematic diagram showing the first type of measuring instrument involved in this utility model example.

[0019] Figure 2 This is a perspective view of another measuring instrument involved in this utility model example.

[0020] Figure 3 This is a three-dimensional schematic diagram showing the X-axis drive structure involved in the example of this utility model.

[0021] Figure 4 This is a three-dimensional schematic diagram showing the crossbeam and linear guide rail involved in this utility model example.

[0022] Figure 5 This is a three-dimensional schematic diagram showing the linear guide rails involved in this utility model being arranged on the same surface of the crossbeam.

[0023] Figure 6This is a three-dimensional schematic diagram of the linear guide rail involved in this utility model example.

[0024] Explanation of reference numerals in the attached figures:

[0025] 11. Slider; 12. Crossbeam; 13. Grating ruler; 131. Grating; 132. Reading head; 133. Grating ruler fixing plate; 14. Linear guide rail; 141. First linear guide rail; 142. Second linear guide rail; 143. Slider assembly; Rr, rolling rotational degree of freedom; Rp, pitch rotational degree of freedom; Ry, horizontal rotational degree of freedom; R1, first rotational degree of freedom; R2, second rotational degree of freedom; R3, third rotational degree of freedom; Detailed Implementation

[0026] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same parts, and repeated descriptions are omitted. Furthermore, the drawings are merely schematic diagrams, and the proportions of the parts or the shapes of the parts may differ from the actual figures.

[0027] Furthermore, the subheadings and similar terms used in the following description of this utility model are not intended to limit the content or scope of this utility model; they are merely for reading guidance. Such subheadings should not be interpreted as dividing the content of the article, nor should the content under a subheading be limited to the scope of that subheading.

[0028] Furthermore, similar elements in different embodiments are referred to by related and similar element designations. In the following embodiments, many details are described to facilitate a better understanding of this application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to this application are not shown or described in the specification. This is to avoid overwhelming the core parts of this application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0029] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0030] Furthermore, the technical solution shown in the accompanying drawings is one feasible embodiment, but should not be construed as the only embodiment of the technical solution. For example, if there is a rectangular structure in the accompanying drawings, the structure can also be any shape such as a triangle, rhombus, or irregular shape without affecting the technical problem to be solved.

[0031] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0032] This utility model relates to an X-axis drive structure that can improve the linearity of the slider's movement. The linearity of the movement can be the linearity of the slider during its movement along the guide rail, or it can be referred to as movement stability, movement accuracy, etc.

[0033] This utility model relates to a measuring instrument having the above-mentioned X-axis drive structure, which enables it to have high probe movement accuracy and thus improve measurement accuracy.

[0034] Figure 1 This is a three-dimensional schematic diagram showing the first type of measuring instrument involved in this utility model example. Figure 2 This is a perspective view of another measuring instrument involved in this utility model example.

[0035] In some examples, the measuring instrument includes a probe, a motion system, and a platform. See also Figure 1-2 The probe can be an optical probe or a contact probe. The probe is used to measure the object under test; specifically, it can acquire geometric quantities such as the shape, surface profile, or height of the measurement point of the object on the platform. The motion system typically includes multiple drive structures corresponding to different directions, thereby controlling the movement of the probe or platform in different directions. In other words, the drive structures can control the relative movement of the probe and the platform in a specific direction. For ease of description, the following explanation will use the example of a drive structure controlling the movement of the probe.

[0036] In some examples, a platform is used to place the object to be measured. The platform can be made of any material. Preferably, the platform can be a marble platform, as marble platforms have high processing precision, which helps to improve the measurement accuracy of the measuring instrument.

[0037] In some examples, the object to be tested can be at least one workpiece.

[0038] In some examples, optical probes can be laser probes, image measurement probes, white light interferometer probes, or confocal probes, while contact probes can be electrically triggered probes, scanning probes, or machine tool probes.

[0039] In some examples, the measuring instrument can be a fixed bridge structure. Specifically, the motion system can control the probe to move in the X and Z directions and control the platform to move in the Y direction. However, it is not limited to this; the measuring instrument can also be a moving bridge structure or a cantilever structure, etc.

[0040] Figure 3 This is a three-dimensional schematic diagram showing the X-axis drive structure involved in the example of this utility model. Figure 4 This is a three-dimensional schematic diagram showing the crossbeam 12 and linear guide rail 14 involved in this utility model example.

[0041] In some examples, the motion system may include at least one drive structure that controls the relative motion between the probe and the platform along a specific direction. For example, the motion system may include an X-axis drive structure that controls the probe to move along the X-axis; the motion system may include a Y-axis drive structure that controls the probe to move along the Y-axis; the motion system may include a Z-axis drive structure that controls the probe to move along the Z-axis. The following description uses the X-axis drive structure as an example, and the specific direction is the X-axis. However, it should be emphasized that the Y-axis drive structure, the Z-axis drive structure, or drive structures in other directions can also use the same structure to solve the technical problems involved in this invention.

[0042] See in some examples Figure 3-4 The X-axis drive structure may include a crossbeam 12, a slider 11 with a probe (not shown) slidably mounted on the crossbeam 12 along the X-axis, a grating ruler 13, and multiple linear guides 14 arranged along the X-axis on the crossbeam 12. The multiple linear guides 14 arranged along the X-axis can achieve a averaging effect (error averaging effect), effectively improving the straightness of the slider 11's movement along the X-axis. For drive structures in other directions, the crossbeam can be replaced with other main structures.

[0043] In some examples, the linear guide 14 includes a guide rail assembly and a plurality of slider assemblies 143. The guide rail assembly is fixedly mounted on the crossbeam 12, and the slider assemblies 143 are fixedly connected to the slider 11, thereby guiding the movement of the slider 11.

[0044] In some examples, the X-axis drive structure includes a transmission mechanism (not shown) mounted on the crossbeam 12. The transmission mechanism can use any transmission method such as lead screw drive, belt drive, synchronous belt drive or gear and rack drive. The transmission mechanism is used to drive the slider 11 to move along the X-axis direction.

[0045] In some examples, the transmission mechanism of the lead screw drive may include a lead screw arranged along the X-axis and a lead screw nut rotatably mounted on the lead screw, the lead screw nut being connected to the slider 11, thereby enabling the slider 11 to move in the X-axis direction by rotating the lead screw.

[0046] In some examples, the crossbeam 12 can be set on the marble platform by at least one column. Preferably, the crossbeam 12 can be set on the marble platform by two columns, with the two columns located on opposite sides of the crossbeam 12.

[0047] In some examples, the columns can be fixedly mounted on the marble platform to ensure rigidity between the columns and the platform, thereby improving accuracy. The columns can also be mounted on the marble platform as part of the Y-axis drive structure, allowing them to move along the Y-axis.

[0048] In some examples, the grating ruler 13 can be arranged along the X-axis and used to measure the position of the slider 11 on the crossbeam 12. The data from the grating ruler 13 can be used for measurement calculations by the measuring instrument.

[0049] In some examples, the probe in the measuring instrument can be configured to move in the Z-axis direction or be fixed in the Z-axis direction. For example, the motion system may also include a Z-axis drive structure, in which the probe can be moved in the Z-axis direction and is fixedly mounted on the slider 11; or the probe may also be fixedly mounted on the slider 11.

[0050] During the measurement process, the workpiece can be placed on a marble platform and positioned in the front direction of the crossbeam 12 (the front and back directions of the crossbeam 12 can be defined based on the position of the probe on the crossbeam 12, where the direction of the crossbeam 12 towards the probe is the front direction, and the direction of the crossbeam 12 away from the probe is the back direction). The probe then measures geometric quantities such as the shape, surface contour, or height of the measurement point of the workpiece on the marble platform. For example, when measuring the length of a line segment, the probe (e.g., a camera, laser probe, or contact probe) can first measure the position of one endpoint of the line segment, and then the slider 11 can be moved to allow the probe to measure the position of the other endpoint. The length of the line segment in the X-axis direction is calculated based on the difference between the two measurements of the grating ruler 13 and the probe data.

[0051] When using measuring instruments, the measurement results continuously change with repeated tests. Furthermore, after a period of inactivity followed by resuming measurement, the results show abrupt changes compared to the previous measurements. Specifically, when measuring length, the results change with repeated tests, exhibiting a generally unidirectional trend. However, after a period of inactivity followed by resuming measurement, the results show abrupt changes, with the direction of the abrupt change opposite to the overall trend. The data obtained after a period of inactivity followed by resuming measurement are roughly the same. For example, the length measurement gradually increases with repeated tests, and after a pause, the length measurement drops significantly, then gradually increases again with repeated tests. To further understand the source of error, the measurement data at both endpoints were analyzed. At the left endpoint of the segment, the measurement results continuously deviated with repeated tests, and after a pause, the results showed a large deviation in the opposite direction. Similarly, at the right endpoint of the segment, the measurement results continuously deviated with repeated tests, and after a pause, the results showed a large deviation in the opposite direction, the opposite of the left endpoint.

[0052] To this end, multiple sets of tests can be performed, including but not limited to: placing the workpiece on the marble platform and arranging it as close as possible to the underside of the crossbeam 12; placing the workpiece on the marble platform and arranging it as far away from the crossbeam 12 as possible; placing the workpiece on the marble platform and arranging it on the back side of the crossbeam 12; placing the workpiece on the crossbeam 12; fixing the reading head 132 of the grating ruler 13 to the marble platform and aligning it with the grating ruler 13 on the crossbeam 12, and recording the reading of the grating ruler 13 in real time; and conducting tests on the position of the probe using an interferometer. It was subsequently found that the farther the distance between the workpiece and the crossbeam 12 or the grating ruler 13, the more obvious the above phenomenon and the more significant the change in the measurement results. Furthermore, after placing the workpiece on the marble platform and arranging it on the back side of the crossbeam 12, the trend of change was opposite to the trend of the original test. Therefore, it can be considered that the phenomenon of "continuous changes in measurement results with multiple tests, and abrupt changes in measurement results relative to the previous measurement results after a period of cessation of testing" is related to the angle between the slider 11 and the crossbeam 12 in the horizontal plane.

[0053] To address this, the mounting surface of at least one linear guide 14 can be altered. In other words, multiple linear guides 14 can include a first linear guide 141 with a first mounting surface on the crossbeam 12 and a second linear guide 142 with a second mounting surface on the crossbeam 12. The first and second mounting surfaces are perpendicular to the X-axis direction, and they have a non-zero angle, allowing the slider assembly 143 of the first linear guide 141 and the slider assembly 143 of the second linear guide 142 to have different orientations. Since the existing linear guide 14 has a guide rail assembly and a corresponding sliding assembly, the guide rail assembly and the sliding assembly slide together, and the sliding assembly encircles the guide rail assembly, ensuring high linearity of movement for the sliding assembly. Therefore, even using only one linear guide 14 theoretically guarantees the linearity of movement for the slider 11. However, in measuring instruments with probes, the existing linearity still cannot meet measurement requirements. In this case, multiple linear guides 14 can be arranged simultaneously to improve the linearity of movement for the slider 11 through a homogenization effect. Furthermore, if multiple linear guides 14 are arranged on the same plane, there is still a large degree of rotational freedom in some directions. In this case, the mounting surfaces of the multiple linear guides 14 are made to have a certain angle, so that the rotational freedom of the linear guides 14 in each direction can be fully utilized, thereby further limiting the rotation of the slider 11.

[0054] In some examples, the first linear guide 141 and the second linear guide 142 may have multiple mounting holes, the multiple mounting holes being oriented in roughly the same direction, and the crossbeam 12 having mounting grooves corresponding to each mounting hole. The first linear guide 141 and the second linear guide 142 are initially installed on the crossbeam 12 using screws, and the screws do not need to be fully tightened, thereby allowing the first linear guide 141 and the second linear guide 142 to swing within a certain range, thereby adjusting the angle or position of the first linear guide 141 and the second linear guide 142. When the angle or position of the first linear guide 141 and the second linear guide 142 is adjusted to a suitable position, the screws are then tightened to achieve fixation.

[0055] In some examples, other mounting methods can be used to further secure the first linear guide 141 and the second linear guide 142, which are already fixed in place. These other mounting methods include, but are not limited to, mounting holes in other directions, limiting components, or adhesives. This can improve the stability of the first linear guide 141 and the second linear guide 142.

[0056] In some examples, the first mounting surface can be the front of the crossbeam 12, and the second mounting surface can be the top surface of the crossbeam 12, wherein the top surface is the side of the crossbeam 12 facing upwards after installation, and the front surface is the side closest to the probe. However, this is not a limitation; the first mounting surface can also be the bottom surface of the crossbeam 12, and the second mounting surface can also be the back surface of the crossbeam 12. In this case, the slider assembly 143 of the first linear guide 141 and the slider assembly 143 of the second linear guide 142 can have different orientations based on the shape of the crossbeam 12.

[0057] In some examples, the included angle between the first mounting surface and the second mounting surface can be any non-zero value, such as 30°, 45°, 60°, or 90°. For example, for a rectangular beam 12, the first mounting surface can be the front surface of the beam 12, and the second mounting surface can be located on the top surface of the beam 12, thereby achieving a 90° included angle.

[0058] In some examples, the X-axis drive structure is located between the first linear guide 141 and the second linear guide 142. This reduces the lever arm and improves the stability of the slider 11's movement.

[0059] Figure 5 This is a perspective view showing the linear guide 14 disposed on the same surface of the crossbeam 12 as described in this utility model example.

[0060] Figure 6 This is a three-dimensional schematic diagram of the linear guide 14 involved in this utility model example.

[0061] See in some examples Figure 3 The slider 11 can have multiple rotational degrees of freedom, including pitch rotational degree of freedom Rp, horizontal rotational degree of freedom Ry, and roll rotational degree of freedom Rr. (See also...) Figure 6 The linear guide 14 may include a slider assembly 143 and a guide rail assembly. A certain gap may exist between the slider assembly 143 and the guide rail assembly, allowing the slider assembly 143 to slide freely on the guide rail assembly. Simultaneously, the gap allows for relative rotation between the slider assembly 143 and the guide rail assembly; in other words, the slider assembly 143 not only slides on the guide rail assembly but also rotates on it. The slider assembly 143 can rotate in three directions. Figure 6 The slider assembly 143 is shown to have several rotational degrees of freedom, including a first rotational degree of freedom R1, a second rotational degree of freedom R2, and a third rotational degree of freedom R3.

[0062] The first rotational degree of freedom R1, the second rotational degree of freedom R2, and the third rotational degree of freedom R3 of the slider assembly 143 can be related to the pitch rotational degree of freedom Rp, the horizontal rotational degree of freedom Ry, and the roll rotational degree of freedom Rr of the slider 11.

[0063] Specifically, since the slider 11 is mounted on the crossbeam 12 via at least the first linear guide rail 141 and the second linear guide rail 142, the rotational degree of freedom of the slider 11 is related to the rotational degree of freedom of each slider assembly 143.

[0064] See Figure 5 If multiple linear guides 14 are all set on the same plane, the rotational degrees of freedom of the slider 11 in each direction are restricted by the corresponding rotational degrees of freedom of the slider assembly 143. For example, the rolling rotational degree of freedom Rr of the slider 11 is restricted by the first rotational degree of freedom R1 of the slider assembly 143; the pitch rotational degree of freedom Rp of the slider 11 is restricted by the second rotational degree of freedom R2 of the slider assembly 143; and the horizontal rotational degree of freedom Ry of the slider 11 is restricted by the third rotational degree of freedom R3 of the slider assembly 143.

[0065] If multiple linear guides 14 are all set on planes at different angles, the rotational degrees of freedom of slider 11 in each direction may be related to the rotational degrees of freedom of slider assembly 143 in any direction, and this relationship is related to the relative positions of slider 11, the first mounting surface, the second mounting surface, and the second mounting surface. For example, when the first mounting surface can be the top surface of the crossbeam 12 and the second mounting surface can be set on the front surface of the crossbeam 12, the rolling rotational degree of freedom Rr of slider 11 is limited by the first rotational degree of freedom R1 of slider assembly 143 of the first linear guide 141 and also by the third rotational degree of freedom R3 of slider assembly 143 of the second linear guide 142; the pitch rotational degree of freedom Rp of slider 11 is limited by the second rotational degree of freedom R2 of slider assembly 143 of the first linear guide 141 and the second linear guide 142; the horizontal rotational degree of freedom Ry of slider 11 is limited by the third rotational degree of freedom R3 of slider assembly 143 of the first linear guide 141 and also by the first rotational degree of freedom R1 of slider assembly 143 of the second linear guide 142. Since the rotational degrees of freedom of the slider assembly 143 in different directions are limited by different contact surfaces, it is difficult to make the rotational degrees of freedom in different directions completely identical. Assuming the relationship between the degrees of freedom of the slider assembly 143 in each direction is: first rotational degree of freedom R1 > second rotational degree of freedom R2 > third rotational degree of freedom R3, where the larger the rotational degree of freedom, the easier it is for the slider assembly 143 to rotate in that direction. In this case, by restricting the rotational degree of freedom of the slider 11 in at least one direction by multiple rotational degrees of freedom of the slider assembly 143, the rotational degree of freedom of the slider 11 in that direction can be more constrained, thereby improving the stability of the slider 11 in that direction. Simultaneously, the relatively smaller rotational degree of freedom of the slider assembly 143 (e.g., the third rotational degree of freedom R3) can limit more rotational directions of the slider, thus fully utilizing the high-precision guiding function of the linear guide rail 14.

[0066] In some examples, multiple slider assemblies 143 can be provided on the linear guide 14, and the multiple slider assemblies 143 are fixedly connected to the slider 11. In this case, the contact points between the entire assembly formed by the slider 11 and the slider assembly 143 and the guide rail assembly can be increased, further improving motion stability.

[0067] In some examples, the distance between the slider assemblies 143 arranged on the same linear guide 14 can be made as large as possible. Specifically, multiple slider assemblies 143 may include two slider assemblies 143 respectively arranged on both sides of the slider 11, thereby obtaining a larger span and improving the motion stability of the slider 11. In some examples, the distance between the two slider assemblies 143 respectively arranged on both sides of the slider 11 can be no less than 50 mm. For example, the distance between the slider assemblies 143 on both sides can be 100 mm, 150 mm, 200 mm, or 300 mm, etc.

[0068] In some examples, the flatness of the first mounting surface and the second mounting surface can be no less than 10 micrometers, but it is not disclosed that it is not limited to this. The flatness of the first mounting surface and the second mounting surface can also be no less than 9 micrometers, no less than 8 micrometers, no less than 7 micrometers, no less than 6 micrometers, no less than 5 micrometers, no less than 4 micrometers, or no less than 3 micrometers. Higher flatness can effectively improve the motion stability of the slider.

[0069] In some examples, the grating ruler 13 can be set along the X-axis direction on the beam 12 and used to measure the position of the slider 11 on the beam 12.

[0070] In some examples, the grating ruler 13 may include a grating ruler fixing plate 133, a grating 131, and a reading head 132. The grating 131 is disposed on the crossbeam 12 along the X-axis direction via the grating ruler fixing plate 133, and the reading head 132 is disposed on the slider 11. The grating ruler fixing plate 133 protrudes from the surface of the slider 11 toward the probe, and the grating 131 is disposed on the portion of the grating ruler fixing plate 133 protruding from the surface of the slider 11 toward the probe. In this case, disposing of the grating 131 on the portion of the grating ruler fixing plate 133 protruding from the surface of the slider 11 toward the probe effectively reduces the distance between the grating 131 and the crossbeam 12 and the probe (or the object to be measured). Since the length measurement structure is angle-dependent, the shorter the distance between the grating 131 and the crossbeam 12 and the probe (or the object to be measured), the smaller the influence, thereby improving accuracy.

[0071] In some examples, the grating ruler fixing plate 133 is disposed at the bottom of the crossbeam 12, the grating 131 is disposed at the bottom of the grating ruler fixing plate 133, and the reading head 132 is disposed at the bottom of the slider 11. In this case, the grating 131 and the reading head 132 can cooperate to measure the position of the slider 11 on the crossbeam 12.

[0072] Although the present invention has been specifically described above in conjunction with the accompanying drawings and embodiments, it is to be understood that the above description does not limit the present invention in any way. Those skilled in the art can make modifications and variations to the present invention as needed without departing from the essential spirit and scope of the present invention, and all such modifications and variations fall within the scope of the present invention.

Claims

1. An X-axis drive structure, characterized in that, The device includes a crossbeam, a slider with a probe that is slidably mounted on the crossbeam in a specific direction, a grating ruler, and multiple linear guides mounted on the crossbeam along the specific direction. Each linear guide includes a guide rail assembly and multiple slider assemblies. The guide rail assembly is fixedly mounted on the crossbeam, and the slider assembly is fixedly connected to the slider. Each linear guide includes a first linear guide with a first mounting surface on the crossbeam and a second linear guide with a second mounting surface on the crossbeam. The first and second mounting surfaces are perpendicular to the specific direction, and they have a non-zero angle so that the slider assemblies of the first and second linear guides have different orientations. The grating ruler is mounted on the crossbeam along the specific direction and is used to measure the position of the slider on the crossbeam.

2. The X-axis drive structure according to claim 1, characterized in that, The grating ruler includes a grating ruler fixing plate, a grating, and a reading head. The grating is disposed on the crossbeam along the specific direction via the grating ruler fixing plate. The reading head is disposed on the slider. The grating ruler fixing plate protrudes from the surface of the slider toward the measuring head. The grating is disposed on the portion of the grating ruler fixing plate that protrudes from the surface of the slider toward the measuring head.

3. The X-axis drive structure according to claim 2, characterized in that, The grating ruler fixing plate is located at the bottom of the crossbeam, the grating is located at the bottom of the grating ruler fixing plate, and the reading head is located at the bottom of the slider.

4. The X-axis drive structure according to claim 1, characterized in that, The first mounting surface is the top surface of the crossbeam, and the second mounting surface is the front surface of the crossbeam.

5. The X-axis drive structure according to claim 1, characterized in that, The included angle between the first mounting surface and the second mounting surface is 30°, 45°, 60° or 90°.

6. The X-axis drive structure according to claim 1, characterized in that, The multiple slider assemblies include two slider assemblies respectively disposed on both sides of the slider, and the distance between the two slider assemblies is not less than 50 mm.

7. The X-axis drive structure according to claim 1, characterized in that, The X-axis drive structure includes a transmission mechanism mounted on the crossbeam. The transmission mechanism is a lead screw drive, belt drive, or synchronous belt drive. The transmission mechanism is used to drive the slider to move along the specific direction.

8. The X-axis drive structure according to claim 7, characterized in that, The transmission mechanism is located between the first linear guide rail and the second linear guide rail.

9. The X-axis drive structure according to claim 1, characterized in that, The flatness of the first mounting surface and the second mounting surface is no greater than 10 micrometers.

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