Differential drive nanometer positioning platform

Abstract

The invention relates to the technical field of positioning platforms, in particular to a differential drive nanometer positioning platform. The positioning platform mainly aims at solving the problems that the adjusting precision of an existing positioning platform driven by a lead screw depends on the lead screw lead, but the lead screw lead has minimum limitation, so that the adjusting precision is limited, and the high-precision application requirement cannot be met. In order to solve the problems, the following technical scheme is provided: the device comprises a base and a working platform positioned above the base; the guide rail assemblies are arranged between the base and the working platform; the differential driving mechanism is installed on the base and comprises a servo motor which is movably arranged, the output end of the servo motor is fixedly connected with a coaxial rod, and the coaxial rod is composed of two lead screws which are the same in rotation direction and different in lead; according to the positioning and adjusting device, the limitation of the minimum lead limit of the lead screw on the adjusting precision is broken through, higher-precision positioning and adjusting can be achieved, and the requirement of a high-precision application scene is met.

Description

Technical Field

[0001] The present invention relates to the technical field of positioning platforms, and in particular to a differential drive nanopositioning platform. Background Art

[0002] The accuracy of positioning platforms plays a crucial role in the development of many cutting-edge technologies. Currently, widely used positioning platforms often utilize screw drives to achieve precise adjustment. The principle of screw drives is to convert rotary motion into linear motion through the rotation of the screw, thereby driving the associated slider or worktable for position adjustment. Adjustment accuracy is largely determined by the screw's lead, that is, the linear distance the slider or worktable moves per one screw rotation.

[0003] However, there is a minimum limit on the lead of the screw. From the perspective of manufacturing technology, a lead that is too small faces great challenges in the processing of the screw. It is difficult to achieve the ideal standard in terms of both cutting accuracy and quality control of forming. At the same time, in actual applications, a screw with an excessively small lead places extremely high torque requirements on the drive device, which is difficult to meet with existing drive technology. In addition, during long-term operation, a screw with a small lead is prone to wear, resulting in a decrease in accuracy. Due to the minimum limit on the lead of the screw, the adjustment accuracy of the positioning platform based on the screw drive is severely restricted. In view of this, the present invention proposes a differential drive nanopositioning platform. Summary of the Invention

[0004] The purpose of the present invention is to propose a differentially driven nanopositioning platform to address the problem that the existing positioning platform driven by a screw in the background technology has an adjustment accuracy that depends on the screw lead, but the screw lead has a minimum limit, resulting in limited adjustment accuracy and inability to meet high-precision application requirements.

[0005] The technical solution of the present invention is as follows: a differentially driven nanopositioning platform, comprising a base and a working platform located above the base; at least one set of guide rail assemblies arranged between the base and the working platform; a differential drive mechanism installed on the base, the differential drive mechanism comprising a movably arranged servo motor, the output end of the servo motor being fixedly connected to a coaxial rod, the coaxial rod being composed of two sections of lead screws with the same rotation direction and different leads, the base and the working platform being respectively engaged with a section of lead screw thread, and when the coaxial rod rotates, the displacement of the working platform is controlled by the difference in the leads of the two lead screws.

[0006] Optionally, the guide rail assembly is installed on the top of the base, and the guide rail assembly is fixedly connected to the bottom of the work platform.

[0007] Optionally, a mounting groove is provided on the top of the base, and the guide rail assembly is installed in the mounting groove.

[0008] Optionally, the differential drive mechanism further comprises a mounting block fixedly connected to the servo motor, a slide rail fixedly connected to one side of the mounting block, a slider slidably connected in the slide rail, and the slider is fixedly connected to the base or the work platform.

[0009] Optionally, the coaxial rod is composed of a first screw rod and a second screw rod coaxially and linearly connected, the first screw rod and the second screw rod are arranged parallel to the guide rail assembly, the second screw rod is threadedly connected to a second threaded sleeve, and the outer ring of the second threaded sleeve is fixedly connected to a fixed plate.

[0010] Optionally, a first threaded sleeve is threadedly connected to the first screw rod, and a connecting plate is fixedly connected to the outer ring of the first threaded sleeve.

[0011] Optionally, the fixing plate and the connecting plate are respectively fixedly connected to the base or the working platform.

[0012] Optionally, it further includes a displacement measuring unit arranged on the side of the base, the displacement measuring unit includes a grating ruler and a reading head, the grating ruler is installed on the side of the base, and the reading head is fixedly connected to the working platform.

[0013] Optionally, it further includes a group of bases and a working platform, a guide rail assembly and a differential drive mechanism arranged thereon, characterized in that the two groups of bases are arranged orthogonally, and the upper group of bases is fixedly connected to the top of the working platform.

[0014] Optionally, the servo motor is in sliding engagement with the base or the work platform.

[0015] In summary, this application includes at least one of the following beneficial technical effects:

[0016] The present invention achieves micro-movement of the work platform by cooperating a first screw and a second screw with the same rotation direction but different leads in a differential drive mechanism, utilizing the displacement difference between the two when they rotate. Compared with the traditional screw drive that relies on the adjustment method of a single lead, this method effectively avoids the limitation of the minimum lead on accuracy and significantly improves positioning accuracy.

[0017] Furthermore, the two sets of guide rail assemblies set between the base and the work platform have rollers arranged in a cross pattern, which can simultaneously withstand loads in multiple directions such as up and down, left and right, and greatly reduce the impact of overturning moments during movement. The guide rail assemblies have more and more evenly distributed contact points, which makes the work platform have a lower friction coefficient and smoother operation during movement, effectively reducing positioning errors caused by guide rail vibration or offset.

[0018] In summary, the present invention breaks through the constraint of the minimum lead of the screw rod on the adjustment accuracy, can achieve higher-precision positioning adjustment, and meet the needs of high-precision application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a schematic diagram of the structure of the differential drive nanopositioning platform;

[0020] Figure 2 yes Figure 1 Schematic diagram of the cross-section structure;

[0021] Figure 3 Schematic diagram of the orthogonal setup of two sets of differentially driven nanopositioning stages.

[0022] Reference numerals:

[0023] 1. Base; 11. Mounting slot; 12. Groove;

[0024] 2. Working platform; 3. Guide rail assembly; 4. Differential drive mechanism; 41. Slider; 42. Slide rail; 43. Mounting block; 44. Servo motor; 45. First screw rod; 46. Second screw rod; 47. Second threaded sleeve; 48. Fixing plate; 49. First threaded sleeve; 410. Connecting plate;

[0025] 5. Displacement measurement unit; 51. Synchronous board. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0027] The components of the embodiments of the present invention generally described and shown in the drawings herein may be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of the invention provided in the drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the invention.

[0028] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative work shall fall within the scope of protection of the present invention.

[0029] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0030] In the description of the present invention, it should be noted that unless otherwise clearly specified and defined, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0031] Embodiment 1

[0032] As Figure 1 shown, the differential drive nano-positioning platform proposed by the present invention includes a base 1 and a working platform 2 located above the base 1. The base 1 is arranged in a "U" - shaped structure. The working platform 2 is arranged parallel to the upper part of the base 1, and the working platform 2 is used to connect devices to achieve precise positioning of the devices.

[0033] Furthermore, the above - mentioned positioning platform further includes at least one set of guide rail components 3 arranged between the base 1 and the working platform 2. The guide rail components 3 are installed on the top of the base 1, and the guide rail components 3 are fixedly connected to the bottom of the working platform 2. An installation groove 11 is formed on the top of the base 1, and the guide rail components 3 are installed in the installation groove 11, making the overall structure of the positioning platform more compact through the installation groove 11. The movement of the working platform 2 is made stable by the arrangement of the guide rail components 3. The guide rail components 3 adopt ball guide rails or crossed roller guide rails, which have higher precision compared with ordinary ball guide rails.

[0034] Specifically, please refer to Figure 1 [[ID=X]]and Figure 2The positioning platform also includes a differential drive mechanism 4 mounted on the base 1. The differential drive mechanism 4 includes a movably arranged servo motor 44. The servo motor 44 slides with the base 1 or the work platform 2. The output end of the servo motor 44 is fixedly connected to a coaxial rod. The coaxial rod is composed of two sections of screws with the same rotation direction and different leads. The base 1 and the work platform 2 are respectively threaded with a section of the screw. When the coaxial rod rotates, the displacement of the work platform 2 changes according to the difference between the two screw leads, thereby achieving more precise displacement. A groove 12 is provided in the base 1. The differential drive mechanism 4 also includes a mounting block 43 fixedly connected to the servo motor 44. When the servo motor 44 moves, it drives the mounting block 43 to move synchronously. A slide rail 42 is fixedly connected to one side of the mounting block 43. A slider 41 is slidably connected to the slide rail 42. The slider 41 is fixedly connected to the groove 12 position or the bottom of the work platform 2. When the position of the slider 41 is fixed, the mounting block 43 moves smoothly under the limiting action of the slider 41 and the slide rail 42. The coaxial rod is composed of a first screw rod 45 and a second screw rod 46 connected coaxially and linearly. After starting, the servo motor 44 drives the first screw rod 45 and the second screw rod 46 to rotate synchronously. The first screw rod 45 and the second screw rod 46 are arranged parallel to the guide rail assembly 3, thereby driving the work platform 2 to be limited by the guide rail assembly 3 when moving. A second threaded sleeve 47 is threadedly connected to the second screw rod 46, and a fixed plate 48 is fixedly connected to the outer ring of the second threaded sleeve 47. The fixed plate 48 is fixedly connected to the base 1. Since the position of the second threaded sleeve 47 and the fixed plate 48 is fixed, the second screw rod 46 moves along its own length when rotating, and at the same time drives the first screw rod 45 and the servo motor 44 to move synchronously. A first threaded sleeve 49 is threadedly connected to the first screw rod 45. When the first screw rod 45 rotates, it drives the first threaded sleeve 49 to move along the length of the first screw rod 45. The outer ring of the first threaded sleeve 49 is fixedly connected to a connecting plate 410 , and the connecting plate 410 is fixedly connected to the bottom of the working platform 2 . When the first threaded sleeve 49 moves, it drives the working platform 2 to move synchronously through the connecting plate 410 .

[0035] It is worth mentioning that since the first screw rod 45 and the second screw rod 46 have the same rotation direction and different leads, assuming the lead of the first screw rod 45 is 0.4 mm and the lead of the second screw rod 46 is 0.5 mm, when the servo motor 44 drives the first screw rod 45 and the second screw rod 46 to rotate one circle, since the second threaded sleeve 47 and the fixed plate 48 are fixed in position, the second screw rod 46 moves 0.5 mm along its own length during one rotation, thereby driving the first screw rod 45 and the servo motor 44 to move 0.5 mm. Since the first screw rod 45 and the second screw rod 46 have the same rotation direction, when the first screw rod 45 rotates one circle, it simultaneously drives the work platform 2 to move 0.4 mm in the opposite direction through the first threaded sleeve 49 and the connecting plate 410. As a result, when the servo motor 44 drives the first screw rod 45 and the second screw rod 46 to rotate one circle, the work platform 2 only moves 0.1 mm, achieving precise adjustment of the position of the work platform 2.

[0036] Finally, the positioning platform also includes a displacement measurement unit 5 mounted on the side of the base 1. This unit 5 includes a grating scale and a reading head. The grating scale is mounted on the side of the base 1, and the reading head is fixedly connected to the work platform 2. The reading head is fixedly connected to a synchronization plate 51, which can be used to securely connect the reading head to the side of the work platform 2, or the synchronization plate 51 can be omitted. The displacement measurement unit 5 is used to accurately measure the distance traveled by the work platform 2, facilitating coordination with the control module to adjust the number of rotations of the servo motor 44, thereby achieving precise adjustment of the position of the work platform 2.

[0037] In this embodiment, the servo motor 44 is started, and the output end of the servo motor 44 drives the first screw 45 and the second screw 46 to rotate synchronously. Since the second screw 46 is threadedly connected to the second threaded sleeve 47 fixed to the base 1, and the second threaded sleeve 47 is relatively fixed to the base 1 via the fixing plate 48, according to the principle of screw transmission, the second screw 46 will move along its own length when rotating, and the movement distance is equal to its lead. Taking the lead of the second screw 46 as an example, if it rotates one circle, it will move 0.5mm in a certain direction, and at the same time drive the first screw 45 and the servo motor 44 to which it is fixed to move synchronously by 0.5mm. The servo motor 44 ensures that this movement process is smooth and linear through the cooperation of the mounting block 43, the slide rail 42 and the slider 41.

[0038] At the same time, the first screw rod 45 rotates while moving with the second screw rod 46. Since the first screw rod 45 is threadedly connected to the first threaded sleeve 49, and the first threaded sleeve 49 is fixed to the work platform 2 via the connecting plate 410, the rotation of the first screw rod 45 drives the first threaded sleeve 49 to move along the length of the first screw rod 45, and the movement distance is equal to the lead of the first screw rod 45. Since the first screw rod 45 and the second screw rod 46 have the same rotation direction, assuming the lead of the first screw rod 45 is 0.4 mm, the first threaded sleeve 49 will drive the work platform 2 to move 0.4 mm in the direction opposite to the movement of the second screw rod 46.

[0039] Through the above-mentioned differential movement, when the servo motor 44 drives the first screw rod 45 and the second screw rod 46 to rotate one circle, the 0.5mm movement brought by the second screw rod 46 and the reverse 0.4mm movement brought by the first screw rod 45 are superimposed, and finally the working platform 2 only produces a displacement of 0.1mm, achieving the effect of amplifying the adjustment accuracy by the lead difference.

[0040] Throughout the adjustment process, the two guide rail assemblies 3 on the bottom of the work platform 2 cooperate with the mounting slots 11 on the base 1 to provide high-precision guidance and support for the work platform 2, ensuring smooth movement. Simultaneously, the displacement measurement units 5 on either side of the base 1 monitor the actual displacement of the work platform 2 in real time via the synchronization board 51 and feed this data back to the control module. Based on this feedback, the control module adjusts the number of revolutions of the servo motor 44 to further ensure the positioning accuracy of the work platform 2.

[0041] Example 2

[0042] like Figures 1 to 3 As shown, based on the first embodiment, the differential drive nanopositioning platform further includes a base 1 and a working platform 2, a guide rail assembly 3 and a differential drive mechanism 4 arranged thereon.

[0043] Specifically, the two sets of bases 1 are arranged orthogonally, and the upper base 1 is fixedly connected to the top of the working platform 2, and the two sets of guide rail assemblies 3 are perpendicular to each other. At the same time, in order to make the structure compact, the thickness of the connection position between the base 1 and the working platform 2 can be reduced.

[0044] In this embodiment, when adjustment is required in a specific direction within the plane of the positioning platform (e.g., the X-axis), the servo motor 44 of the lower positioning platform is activated. Through the differential motion of the first and second screws 45 and 46, the work platform 2 below is driven to produce high-precision displacement along the guide rail assembly 3 (the X-axis). The displacement is determined by the difference in the leads of the two screws. Simultaneously, the guide rail assembly 3 below ensures smooth movement of the work platform 2 in the X-axis, and the displacement measurement unit 5 below monitors the displacement in real time and provides feedback to ensure positioning accuracy in the X-axis.

[0045] The upper base 1 is fixedly connected to the top of the lower work platform 2, and the two sets of guide rail assemblies 3 are perpendicular to each other (i.e., the upper guide rail assembly 3 is along the Z-axis). When adjustment is required in a direction perpendicular to the lower adjustment direction (the Z-axis), the upper servo motor 44 is activated, and the first and second lead screws 45, 46 within it also drive the upper work platform 2 along the Z-axis through differential motion. Because the work platform 2 as a whole moves synchronously with the lower work platform 2, the actual displacement of the upper work platform 2 is the superposition of the lower work platform 2's X-axis displacement and its own Z-axis displacement.

[0046] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant inspirations of the above embodiments, those skilled in the art may make various alternative improvements and combinations to the above specific embodiments.

Claims

1. Differential drive nanopositioning stage, characterized by: include: A base (1) and a working platform (2) located above the base (1); At least one set of guide rail components (3) arranged between the base (1) and the working platform (2); A differential drive mechanism (4) is mounted on the base (1), the differential drive mechanism (4) comprising a movably arranged servo motor (44), the output end of the servo motor (44) being fixedly connected to a coaxial rod, the coaxial rod being composed of two sections of screw rods having the same rotation direction and different leads, the base (1) and the working platform (2) being respectively threadedly engaged with a section of the screw rod, and when the coaxial rod rotates, the displacement of the working platform (2) is controlled by the difference in the leads of the two screw rods.

2. The differential drive nanopositioning platform according to claim 1, characterized in that: The guide rail assembly (3) is installed on the top of the base (1), and the guide rail assembly (3) is fixedly connected to the bottom of the working platform (2).

3. The differential drive nanopositioning platform according to claim 2, characterized in that: A mounting groove (11) is provided on the top of the base (1), and the guide rail assembly (3) is installed in the mounting groove (11).

4. The differential drive nanopositioning platform according to claim 3, characterized in that: The differential drive mechanism (4) further comprises a mounting block (43) fixedly connected to the servo motor (44), a slide rail (42) fixedly connected to one side of the mounting block (43), a slider (41) slidably connected to the slide rail (42), and the slider (41) fixedly connected to the base (1) or the work platform (2).

5. The differential drive nanopositioning platform according to claim 4, characterized in that: The coaxial rod is composed of a first screw rod (45) and a second screw rod (46) connected coaxially and linearly. The first screw rod (45) and the second screw rod (46) are arranged parallel to the guide rail assembly (3). A second threaded sleeve (47) is threadedly connected to the second screw rod (46), and a fixing plate (48) is fixedly connected to the outer ring of the second threaded sleeve (47).

6. The differential drive nanopositioning platform according to claim 5, characterized in that: A first threaded sleeve (49) is threadedly connected to the first screw rod (45), and a connecting plate (410) is fixedly connected to the outer ring of the first threaded sleeve (49).

7. The differential drive nanopositioning platform according to claim 6, characterized in that: The fixing plate (48) and the connecting plate (410) are respectively fixedly connected to the base (1) or the working platform (2).

8. The differential drive nanopositioning platform according to claim 7, characterized in that: It also includes a displacement measuring unit (5) arranged on the side of the base (1), the displacement measuring unit (5) including a grating ruler and a reading head, the grating ruler is installed on the side of the base (1), and the reading head is fixedly connected to the working platform (2).

9. The differential drive nanopositioning platform according to claim 8, characterized in that: The invention also comprises a group of bases (1) and a working platform (2) arranged thereon, a guide rail assembly (3) and a differential drive mechanism (4), and is characterized in that the two groups of bases (1) are arranged orthogonally, and the upper group of bases (1) is fixedly connected to the top of the working platform (2).

10. The differential drive nanopositioning platform according to claim 1, wherein: The servo motor (44) is in sliding cooperation with the base (1) or the working platform (2).

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