High stability and high precision servo-screw rod electric translation stage

Abstract

The application relates to the technical field of electric translation tables, and particularly discloses a high-stability and high-precision servo screw electric translation table which comprises a base, a sliding table seat is arranged at the upper portion of the base, a recessed cavity is formed in the middle portion between the sliding table seat and the base, a servo driving mechanism is arranged in the recessed cavity, the servo driving mechanism is used for driving the sliding connection between the sliding table seat and the base, the servo driving mechanism comprises a screw rod transmission mechanism, one end of the screw rod transmission mechanism extends to the outside of the recessed cavity and is connected with a servo motor, the output end of the screw rod transmission mechanism is connected with the sliding table seat, an incremental encoder is arranged in the servo motor, and a linear grating ruler is arranged between the base and the sliding table seat; high-precision full-closed-loop control of the electric translation table is realized, so that the full-closed-loop repeated positioning precision of the electric translation table is extremely high.

Description

Technical Field

[0001] This invention relates to the field of electric translation stage technology, and in particular to a high-stability and high-precision servo screw electric translation stage. Background Technology

[0002] High-precision electric translation stages are core moving components in precision optical systems (such as secondary mirror focusing mechanisms). In such applications, translation stages typically need to operate in complex environments involving light emission during movement, wide temperature ranges, and continuous vibration. Therefore, extremely high requirements are placed on the stability and positioning accuracy of the mechanical structure.

[0003] Currently, the most common electric translation stages in existing technologies mainly include two technical approaches: stepper motor lead screw translation stages and voice coil motor translation stages.

[0004] The first type is the stepper motor lead screw translation stage, which is usually driven by a stepper motor through a coupling to drive a ball screw or trapezoidal lead screw for transmission. The helical transmission of the lead screw converts rotational motion into linear motion. Although this structure is simple and has a certain mechanical self-locking capability, it mostly adopts an open-loop control method, which is prone to "step loss" when the load changes suddenly or the response is high speed. In addition, there is always a mechanical fit clearance between the nut and the lead screw in the traditional lead screw transmission mechanism. This will cause the translation stage to produce an "unavoidable backlash error" when it moves in reverse, which is difficult to meet the micron-level bidirectional repeatability positioning accuracy requirements of optical systems.

[0005] The second type is the voice coil motor (VCM) direct-drive translation stage, which uses a voice coil motor for direct drive. It has the advantages of fast response speed and no mechanical backlash. However, the voice coil motor is essentially a magnetic levitation "soft connection" drive, which lacks mechanical self-locking ability, has low stiffness, and poor resistance to vibration interference. When the power is off or it is subjected to external impact, the slide position is prone to drift. At the same time, the voice coil motor needs to be continuously powered to maintain a specific position. If the large amount of Joule heat generated cannot be dissipated in time, it will cause thermal deformation of the surrounding mechanical structure, thereby affecting the stability of the optical path of the optical components.

[0006] In addition, regarding the guiding mechanism, traditional cross roller guides are prone to cumulative displacement (i.e., creep) relative to the guide body under long-term high-frequency reciprocating motion or vibration environment, which affects the stroke range and motion stability.

[0007] In summary, existing technologies cannot simultaneously achieve the comprehensive performance of high rigidity and vibration resistance, low thermal deformation, and high-precision positioning in a fully closed-loop manner. Therefore, there is an urgent need for a highly stable and high-precision servo screw electric translation stage. Summary of the Invention

[0008] The main objective of this invention is to provide a highly stable and high-precision servo screw electric translation stage, aiming to at least solve one of the aforementioned problems existing in the prior art.

[0009] To achieve the above objectives, the present invention provides a high-stability and high-precision servo screw electric translation stage, comprising a base, a slide seat on the upper part of the base, and a recessed cavity formed in the middle between the slide seat and the base. A servo drive mechanism is provided in the recessed cavity, which is used to drive the slide seat to slide and connect with the base. The servo drive mechanism includes a screw transmission mechanism, one end of which extends to the outside of the recessed cavity and is connected to a servo motor. The output end of the screw transmission mechanism is connected to the slide seat. An incremental encoder is provided inside the servo motor, and a linear grating ruler is provided between the base and the slide seat.

[0010] In some alternative embodiments, the lead screw drive mechanism includes a lead screw and two nuts that are meshed and sleeved on the outside of the lead screw and spaced apart along its axial direction. A preload spring is also provided between the two nuts and coaxially sleeved with the lead screw, and the tops of the two nuts are connected to the slide base.

[0011] In some optional embodiments, a cross roller guide is further provided between the base and the slide seat. The cross roller guide is located on both sides of the screw drive mechanism. Each of the cross roller guides includes a first guide and a second guide. The sides of the first guide and the second guide are fixedly connected to the corresponding base and the slide seat, and a retaining component is used to slide between the second guide and the first guide.

[0012] In some alternative embodiments, the cage assembly includes a cage body and an array of cross rollers embedded in the cage body, with guide grooves axially formed on the opposite sides of the first guide rail and the second guide rail, the guide grooves engaging with the cross rollers in a rolling manner.

[0013] In some alternative embodiments, an anti-creep gear is rotatably provided in the middle of the cage body, and a rack is provided in the middle of the guide groove of the first guide rail and the second guide rail, and the rack meshes with the anti-creep gear.

[0014] In a further optional embodiment, the linear grating ruler includes a reading head and a grating ruler strip. The reading head is fixedly mounted on the base, and the grating ruler strip is fixedly mounted on the side of the slide base, with the reading head and the grating ruler strip arranged opposite to each other.

[0015] In some preferred embodiments, a controller is also included, which is electrically connected to the servo motor, the incremental encoder and the linear encoder respectively.

[0016] Compared with the prior art, the beneficial effects that the present invention can achieve include at least the following:

[0017] 1. This solution solves the technical defects of insufficient rigidity of existing voice coil motor drives and easy step loss of stepper motor drives by adopting a rigid drive method of servo motor and lead screw transmission mechanism. Specifically, it realizes the establishment of axial mechanical holding force between servo motor and slide base by utilizing the mechanical meshing characteristics of lead screw transmission chain. Even in the vibration environment during movement or in the power failure state, it can effectively suppress the position drift of slide base, thereby ensuring the physical stability of slide base in uncontrolled state.

[0018] 2. This solution solves the technical problem that traditional semi-closed-loop control cannot eliminate errors in the intermediate transmission links by using an incremental encoder inside the motor and an external linear grating ruler to build a dual feedback architecture. Specifically, it realizes the use of incremental feedback to ensure dynamic response and the use of absolute feedback to directly detect the actual displacement of the slide block, thereby compensating and correcting the thermal expansion of the lead screw and the mechanical transmission clearance in real time, ensuring the extremely high full closed-loop repeatability of the electric translation stage.

[0019] 3. This solution addresses the inherent backlash error during screw reversal and the creep misalignment problem of the guide rail cage during long-term operation by employing a double-nut, pre-loaded spring elastic preload structure in the screw drive mechanism, combined with a cross roller guide rail equipped with an anti-creep gear and rack meshing mechanism. Specifically, it utilizes spring tension to physically eliminate thread assembly clearance and uses the mechanical constraints of the gear and rack to ensure the long-term integrity of the guide stroke, thus ensuring the reliability of the mechanism under complex working conditions. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0021] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the present invention;

[0022] Figure 2 For the present invention Figure 1 A schematic diagram of the side cross-sectional structure;

[0023] Figure 3 For the present invention Figure 1 The schematic diagram of the three-dimensional structure without the slide base is intended to illustrate the screw drive mechanism;

[0024] Figure 4For the present invention Figure 3 A top-view structural diagram;

[0025] Figure 5 This is a partial structural schematic diagram of the cross roller guide of the present invention.

[0026] In the above figures, the reference numerals are as follows: 1. Base; 2. Slide table base; 31. Screw drive mechanism; 311. Screw; 312. Nut; 313. Preload spring; 32. Servo motor; 41. First guide rail; 42. Second guide rail; 431. Cage body; 432. Cross roller; 433. Anti-creep gear; 434. Rack; 435. Guide groove; 5. Linear grating ruler; 6. Incremental encoder.

[0027] The realization of the objective, functional features and advantages of the present invention will be further explained below with reference to the embodiments and the accompanying drawings. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0030] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0031] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0032] Example:

[0033] This embodiment provides a highly stable and high-precision servo screw electric translation stage. Obviously, this platform is used in precision optical systems with extremely high requirements for axial rigidity, dynamic response and environmental adaptability. Specifically, it is located at the mounting base of optical components (such as vehicle-mounted or airborne secondary mirror focusing mechanisms) and is used to carry sensitive optical loads to perform linear reciprocating focusing motion with micron-level precision.

[0034] For example, please refer to Figures 1 to 2 Its specific structure includes a base 1, a slide seat 2 on the upper part of the base 1, a recessed cavity formed in the middle between the slide seat 2 and the base 1, a servo drive mechanism is provided in the recessed cavity, the servo drive mechanism is used to drive the slide seat 2 to slide and connect with the base 1, the servo drive mechanism includes a lead screw transmission mechanism 31, one end of the lead screw transmission mechanism 31 extends to the outside of the recessed cavity and is connected to a servo motor 32, the output end of the lead screw transmission mechanism 31 is connected to the slide seat 2, an incremental encoder 6 is provided inside the servo motor 32, and a linear grating ruler 5 is provided between the base 1 and the slide seat 2.

[0035] This solution, through the aforementioned structural design, effectively addresses the stability and accuracy deficiencies inherent in existing technologies that utilize voice coil motors and drive stepper motors. Specifically, this solution employs a drive method combining a servo motor 32 with a lead screw transmission mechanism 31. By utilizing the mechanical meshing characteristics of the lead screw transmission mechanism 31, a rigid connection is established between the output end of the servo motor 32 and the slide base 2. Compared to a voice coil motor driven by magnetic levitation, the lead screw 311 transmission chain can provide axial mechanical holding force. When the translation stage is in a vibration environment during travel or in a power-off state, this mechanical holding force can suppress positional drift of the slide base 2, thereby ensuring the physical stability of the slide base 2 in an uncontrolled state.

[0036] Secondly, this solution utilizes an incremental encoder 6 and a linear encoder 5 to construct a dual feedback architecture. On the one hand, the incremental encoder 6, located inside the servo motor 32, can monitor the rotation state of the motor rotor in real time, providing speed and current feedback for servo control, ensuring that the motor can respond to sudden load changes and avoiding the open-loop step loss phenomenon of the stepper motor. On the other hand, the linear encoder 5, located between the base 1 and the slide table 2, directly detects the actual displacement of the slide table 2, eliminating the influence of errors in the intermediate transmission links, thereby achieving a high-precision closed loop for the electric translation stage.

[0037] In addition, it should be added that by placing the servo drive mechanism in the recessed cavity between the slide table 2 and the base 1, this solution achieves the embedded and compact installation of the transmission components, effectively reducing the overall center of gravity height of the translation stage and reducing the overturning torque during the movement. On the other hand, this highly integrated design significantly reduces the volume envelope of the device, making it easier to integrate into the space-constrained optical focusing module.

[0038] Furthermore, in some preferred embodiments, the base 1 and the slide 2 may be made of materials with a low coefficient of thermal expansion (e.g., indium steel, with a coefficient of thermal expansion of approximately 1.2 × 10⁻). 6 Made of materials that are 100°C or 100°C, this material is used to further offset the thermal expansion caused by changes in ambient temperature and motor temperature rise, ensuring the long-term thermal stability of the optical system.

[0039] In some alternative embodiments, such as Figure 3 and Figure 4 As shown, the lead screw transmission mechanism 31 includes a lead screw 311 and two nuts 312 that are meshed and sleeved on the outside of the lead screw 311 and spaced apart along its axial direction. A preload spring 313 is also provided between the two nuts 312 and coaxially sleeved with the lead screw 311. The tops of the two nuts 312 are connected to the slide base 2.

[0040] In the lead screw drive mechanism 31, to ensure smooth rotation of the nut 312, a small assembly clearance must be maintained between the internal thread of the nut 312 and the external thread of the lead screw 311. When the lead screw 311 rotates in the opposite direction, this clearance causes the nut 312 to have an invalid free-spinning stroke before driving the load, i.e., reverse free-spinning (free-spinning error), which directly affects the repeatability of the electric translation stage. Therefore, this solution solves this problem through the above structure. For example,

[0041] Since the preload spring 313 is located between the two nuts 312 and coaxially sleeved on the outside of the lead screw 311, under the action of the axial tension of the preload spring 313, it will always apply a corresponding tension to the nuts 312 at both ends. Therefore, under the action of this tension, the two nuts 312 will have a tendency to move away from each other along the axial direction of the lead screw 311, so as to force the internal thread tooth surfaces of the two nuts 312 to be tightly attached to the opposite side lead surfaces of the external thread of the lead screw 311.

[0042] Therefore, through the bidirectional tensioning fit of the above structure, the assembly gap between the nut 312 and the lead screw 311 is forcibly filled, so that the lead screw 311 can directly transmit driving force without overcoming invalid stroke when changing direction, thereby effectively eliminating the backlash error and ensuring the repeatability of the electric translation stage.

[0043] In some alternative embodiments, in Figure 3 and Figure 4 As shown in the diagram, a cross roller 432 guide rail is also provided between the base 1 and the slide table 2. The cross roller 432 guide rails are located on both sides of the lead screw transmission mechanism 31, and each of the cross roller 432 guide rails includes a first guide rail 41 and a second guide rail 42. The sides of the first guide rail 41 and the second guide rail 42 are fixedly connected to the corresponding base 1 and slide table 2, and the second guide rail 42 and the first guide rail 41 are slidably engaged by a retaining component.

[0044] Understandably, based on the above embodiments, this solution utilizes the first guide rail 41 and the second guide rail 42 respectively fixed on both sides of the base 1 and the slide table 2, in conjunction with the retaining component located between them, to construct a stable lateral support structure on both sides of the screw drive mechanism 31; while realizing the relative sliding engagement between the first guide rail 41 and the second guide rail 42, the retaining component restricts the degree of freedom of the slide table 2 in the non-movement direction, thereby ensuring that the slide table 2 can perform highly stable linear reciprocating motion along the preset trajectory and effectively withstand the lateral torque from the load.

[0045] In some alternative embodiments, such as Figure 5 As shown, the cage assembly includes a cage body 431 and an array of cross rollers 432 embedded in the cage body 431. Guide grooves 435 are respectively provided axially on the opposite sides of the first guide rail 41 and the second guide rail 42, and the guide grooves 435 are in rolling engagement with the cross rollers 432.

[0046] Understandably, for conventional precision guiding mechanisms, if traditional sliding guides (such as dovetail grooves) are used, they rely on sliding friction between contact surfaces. Since the static friction coefficient is significantly greater than the dynamic friction coefficient, nonlinear "creeping" phenomena are easily generated during micro-distance initiation, making it difficult to achieve micron-level precise response. On the other hand, if ordinary ball guides are used, the balls and raceways only have point contact, which is prone to contact deformation when bearing lateral torque or heavy loads, resulting in insufficient overall rigidity of the guiding system.

[0047] This embodiment solves the problems of insufficient rigidity and excessive motion resistance of the guide mechanism when subjected to complex loads, based on the above solution.

[0048] Thus, the cage body 431 achieves orderly spacing and positioning of multiple cross rollers 432, avoiding direct contact and wear between adjacent rollers. At the same time, by utilizing the embedded cross rollers 432 to roll within the guide groove 435, the relative motion between the first guide rail 41 and the second guide rail 42 is transformed into low-resistance rolling friction. This significantly reduces the moving friction resistance of the slide seat 2 and eliminates low-speed crawling. Meanwhile, the line contact support structure formed by the cross rollers 432 and the guide groove 435 can effectively withstand combined loads from vertical and lateral directions, ensuring the high rigidity and stability of the electric translation stage during precision movement.

[0049] In some alternative embodiments, an anti-creep gear 433 is rotatably provided in the middle of the cage body 431, and a rack 434 is provided in the middle of the guide groove 435 of the first guide rail 41 and the second guide rail 42, and the rack 434 meshes with the anti-creep gear 433.

[0050] For traditional cross roller 432 guide rails, positioning and floating usually rely solely on the friction between the rollers and the guide rail surface. When the equipment is in high-frequency reciprocating motion, vertically installed, or subjected to vibration and impact, the cage is prone to slight slippage due to inertia or uneven force. This slight slippage will gradually accumulate during long-term operation, causing the cage to deviate from the center position (i.e., the "creeping" phenomenon), ultimately resulting in limited guide rail travel or mechanical interference.

[0051] Therefore, this embodiment, based on the aforementioned gear and rack 434 structure, effectively solves the problem of cage position displacement that is prone to occur during long-term operation.

[0052] Specifically, by utilizing the meshing between the anti-creep gear 433 and the rack 434 provided on the first guide rail 41 and the second guide rail 42, a rigid mechanical connection is established between the axial movement of the cage body 431 and the relative movement of the guide rails. This mechanical connection directly constrains the displacement of the cage body 431, requiring it to move synchronously with the guide rails according to the transmission ratio of the gear and rack 434. This avoids slippage or accumulated positional deviation of the cage body 431 relative to the guide rails due to changes in friction or vibration, thus ensuring the integrity of the effective stroke of the guiding mechanism.

[0053] In a further optional embodiment, the linear grating ruler 5 includes a reading head and a grating ruler strip. The reading head is fixedly installed on the base 1, and the grating ruler strip is fixedly installed on the side of the slide base 2, with the reading head and the grating ruler strip arranged opposite to each other.

[0054] This embodiment solves the problem of parasitic interference caused by the movement of cables in traditional displacement detection based on the above solution. Specifically, it adopts an inverted installation strategy with a fixed reading head and a movable grating ruler. The reading head, which needs to be connected to electrical cables, is placed on the stationary base 1 side, while the passive and lightweight grating ruler is placed on the moving slide 2 side.

[0055] Obviously, this structural layout keeps the signal transmission cable of the reading head stationary during operation, thereby physically eliminating the variable resistance or elastic stress caused by bending and dragging of the cable during reciprocating motion. This ensures that the motion characteristics of the slide base 2 are not affected by the cable, further improving the stability and repeatability of its micron-level positioning.

[0056] In some preferred embodiments, a controller is also included, which is electrically connected to the servo motor 32, the incremental encoder 6, and the linear encoder 5, respectively.

[0057] Based on the above embodiments, this solution constructs a fully closed-loop control system with dual feedback between the motor end and the load end, which solves the problem of load end positioning deviation caused by mechanical transmission chain errors (such as thermal elongation and elastic deformation of the lead screw 311) in traditional semi-closed-loop control.

[0058] Specifically, the controller is configured to operate using a three-loop control strategy: position loop, speed loop, and current loop.

[0059] First, at the inner loop control level, the controller uses the incremental encoder 6 to collect the real-time speed and angle increment signals of the motor, which serves as the feedback basis for the speed loop and current loop, ensuring the dynamic response characteristics and commutation smoothness of the servo motor 32 during high-speed start-stop process.

[0060] Secondly, at the outer loop control level, the controller uses a linear grating ruler 5 (e.g., an absolute grating ruler) to collect the actual absolute position signal of the slide table 2, and compares the actual absolute position signal with the preset target position command in real time to calculate the position deviation value including mechanical transmission error.

[0061] Finally, based on the aforementioned position deviation value, the controller generates a compensation command and superimposes it into the drive signal of the servo motor 32, driving the servo motor 32 to perform a slight correction rotation. Through this dual closed-loop feedback mechanism, the controller can automatically compensate for the backlash error and thermal deformation error in the lead screw transmission mechanism 31, ensuring that the final stopping position of the slide table 2 strictly matches the target command, thereby achieving micron-level repeatability positioning accuracy of the electric translation stage.

[0062] To facilitate technical personnel's further understanding of this technical solution, its working process is explained as follows:

[0063] Furthermore, in order to verify the comprehensive performance indicators of the servo screw electric translation stage described in this embodiment under actual working conditions, a number of targeted performance tests were conducted on it.

[0064] Specifically, the experiment selected three typical operating conditions: a conventional static desktop environment, an extreme high and low temperature environment, and a dynamic sweep frequency vibration environment, to test and calibrate the positioning accuracy and operating status of the equipment. The experimental data are shown in Table 1:

[0065] Table 1: Performance Test Data of Servo Screw Electric Translation Stage

[0066]

[0067] Based on the experimental data in Table 1, thanks to the real-time compensation of transmission error by the dual closed-loop control architecture, the repeatability of the translation stage under normal temperature static conditions can reach ±0.4μm, which is far superior to conventional stepper motor translation stages.

[0068] Meanwhile, in terms of environmental adaptability, the test results show that in a wide temperature range of -40℃ to 60℃, thanks to the selection of materials with low thermal expansion coefficient (such as indium steel) and thermal deformation compensation mechanism, its positioning accuracy has not been reduced and remains stable at ±0.4μm, proving that the solution has excellent thermal stability.

[0069] Furthermore, in the most stringent frequency sweep vibration test (5-80Hz wideband coverage, maximum acceleration 1.5g), the experimental results show that the dynamic positioning accuracy of the electric translation stage can still be maintained within ±2μm. According to the general technical standards for precision optical systems, if the positioning accuracy of the focusing mechanism can reach ±2μm, the emitted optical path can be considered stable and the impact effect meets the standard.

[0070] In summary, the servo-driven ball screw electric translation stage described in this solution not only possesses ultra-high precision at the sub-micron level (±0.4μm) under static and constant temperature conditions, but more importantly, it maintains high stability while meeting optical specifications (±2μm) even under harsh vibration environments such as during travel or on bumpy roads. This comprehensive performance significantly outperforms voice coil motor translation stages with poor vibration resistance and stepper motor translation stages prone to step loss, perfectly meeting the application requirements of precision optical components for both high precision and high stability.

[0071] Finally, it should be noted that in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0072] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0073] Furthermore, it should be noted that the structures, proportions, sizes, etc., illustrated in the accompanying drawings of this specification are all schematic diagrams, intended only to complement the content disclosed in the specification for those skilled in the art to understand and read, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

Claims

1. A high-stability and high-precision servo lead screw (311) electric translation stage, comprising a base (1), characterized in that, The base (1) is provided with a slide seat (2) on the upper part. A recessed cavity is formed in the middle between the slide seat (2) and the base (1). A servo drive mechanism is provided in the recessed cavity. The servo drive mechanism is used to drive the slide seat (2) to slide and connect with the base (1). The servo drive mechanism includes a lead screw drive mechanism (31). One end of the lead screw drive mechanism (31) extends to the outside of the recessed cavity and is connected to a servo motor (32). The output end of the lead screw drive mechanism (31) is connected to the slide seat (2). An incremental encoder (6) is provided inside the servo motor (32). A linear grating ruler (5) is provided between the base (1) and the slide seat (2).

2. The high-stability and high-precision servo lead screw (311) electric translation stage according to claim 1, characterized in that, The lead screw drive mechanism (31) includes a lead screw (311) and two nuts (312) that are meshed and sleeved on the outside of the lead screw (311) and spaced apart along its axial direction. A preload spring (313) is also provided between the two nuts (312) and is coaxially sleeved with the lead screw (311). The tops of the two nuts (312) are connected to the slide base (2).

3. The high-stability and high-precision servo lead screw (311) electric translation stage according to claim 2, characterized in that, A cross roller (432) guide rail is provided between the base (1) and the slide seat (2). The cross roller (432) guide rail is located on both sides of the screw drive mechanism (31). Each of the cross roller (432) guide rails includes a first guide rail (41) and a second guide rail (42). The sides of the first guide rail (41) and the second guide rail (42) are fixedly connected to the corresponding base (1) and slide seat (2), and the second guide rail (42) and the first guide rail (41) are slidably engaged by a retaining component.

4. The high-stability and high-precision servo lead screw (311) electric translation stage according to claim 3, characterized in that, The cage assembly includes a cage body (431) and an array of cross rollers (432) embedded in the cage body (431). Guide grooves (435) are respectively provided axially on the opposite sides of the first guide rail (41) and the second guide rail (42). The guide grooves (435) are in rolling engagement with the cross rollers (432).

5. The high-stability and high-precision servo lead screw (311) electric translation stage according to claim 4, characterized in that, An anti-creep gear (433) is rotatably provided in the middle of the cage body (431), and a rack (434) is provided in the middle of the guide groove (435) of the first guide rail (41) and the second guide rail (42), and the rack (434) meshes with the anti-creep gear (433).

6. The high-stability and high-precision servo lead screw (311) electric translation stage according to claim 1, characterized in that, The linear grating ruler (5) includes a reading head and a grating ruler strip. The reading head is fixedly installed on the base (1), and the grating ruler strip is fixedly installed on the side of the slide base (2). The reading head and the grating ruler strip are arranged opposite to each other.

7. The high-stability and high-precision servo lead screw (311) electric translation stage according to claim 6, characterized in that, It also includes a controller, which is electrically connected to the servo motor (32), the incremental encoder (6) and the linear grating ruler (5).

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