Parallel drive displacement mechanism and movable diaphragm mechanism

Abstract

The utility model belongs to the technical field of displacement transmission devices, and relates to a parallel drive displacement mechanism and a movable diaphragm mechanism. The parallel driving displacement mechanism comprises a first driving assembly and a second driving assembly which are oppositely arranged, each driving assembly comprises a linear sliding table, a translation sliding block and a connecting rod unit, and the near ends of the two connecting rod units are rotationally connected with displacement tables. The two groups of linear sliding tables drive the translation sliding blocks to move oppositely to change the Y coordinate value of the displacement table, the same-direction movement can change the X coordinate value of the displacement table, and one group of linear sliding tables can drive the displacement table to move in an arc shape independently. The connecting rod unit comprises two connecting rods arranged in parallel, and the connecting rods, the translation sliding block and the displacement table form a parallelogram component. The two-dimensional displacement control mechanism is simple in structure, capable of achieving stroke differentiation in a two-dimensional plane and complex movement in the plane, and suitable for a movement system needing accurate displacement control.

Description

Technical Field

[0001] The utility model belongs to the technical field of displacement transmission devices, and particularly relates to a parallel drive displacement mechanism and a movable aperture mechanism. Background Art

[0002] Traditionally, an XY linear slide primarily consists of two identical linear slides, one acting on a slider along the X-axis and the other along the Y-axis, collectively achieving motion within the XY plane. However, traditional XY slide assemblies have identical travel in both directions, and their range of motion is typically limited, making them difficult to meet the requirements of certain specialized applications where a large travel in one direction and a small travel in the other are required. This traditional dual-component stacking approach results in a larger footprint, increasing the overall system size and weight.

[0003] Therefore, in the application of the movable aperture mechanism, the XY linear slide in the prior art is difficult to simultaneously meet the requirements of stroke differentiation and complex motion trajectory, which limits its application in high-precision optical systems.

[0004] Parallel mechanisms have attracted widespread attention due to their high rigidity, high precision, and good dynamic performance. For example, CN113370189A discloses a high-rigidity three-translation redundant drive parallel mechanism, which includes a fixed platform, a moving platform, and four branched chain units. The rigidity and load-bearing capacity of the three-translation parallel mechanism are improved through a special connecting rod arrangement. CN206536451U provides an orthogonal three-degree-of-freedom translation parallel robot mechanism, which includes a machine base, two gantries, a translation platform, and four branches arranged between the two gantries, the machine base, and the moving platform, which are spatially orthogonal to each other. This enables the moving platform to move precisely along a preset trajectory.

[0005] While existing parallel mechanisms offer advantages in certain areas, most designs focus on achieving translational or rotational motion within three-dimensional space, with insufficient consideration given to applications requiring specific trajectories within a plane (such as arc-shaped motion). Furthermore, existing displacement mechanisms also have room for improvement in the use of elastic elements, position detection, and compatibility with vacuum environments.

[0006] Therefore, there is an urgent need for a parallel drive displacement mechanism with a compact structure, differentiated stroke, ability to achieve complex in-plane motion, and suitability for special environments to meet the special needs of modern precision instruments and optical systems. Utility Model Content

[0007] In order to solve the technical problems that the traditional XY slide assembly has the same stroke in two directions and a small movable range, the two directional components stacked together occupy too much space, cannot meet the actual requirements of one large and one small stroke, and cannot achieve complex movements, the utility model provides a parallel drive displacement mechanism.

[0008] The parallel drive displacement mechanism includes: a drive component 1 and a drive component 2 arranged opposite to each other, each of the drive component 1 and the drive component 2 including a linear slide, a translation slider located at the output end of the linear slide, and a connecting rod unit hinged to the translation slider, the proximal ends of the two groups of the connecting rod units are rotatably connected to the displacement platform; the two groups of the linear slides respectively drive the two groups of the translation sliders to move in opposite directions at equal speeds, thereby changing the Y coordinate value of the displacement platform; the two groups of the linear slides respectively drive the two groups of the translation sliders to move in the same direction at equal speeds, thereby changing the X coordinate value of the displacement platform; one group of the linear slides does not move, and the other group of the linear slides drives the translation sliders to move, causing the displacement platform to move in an arc.

[0009] Preferably, the connecting rod unit includes two connecting rods arranged in parallel, and both ends of the connecting rods are respectively hinged to the translation slider and the displacement platform to form a parallelogram component.

[0010] Preferably, the linear slide includes a through-axis motor, a compression spring is installed on the screw rod of the through-axis motor, and the compression spring is located between the through-axis motor and the translation slider, and is used to apply thrust to the translation slider.

[0011] Preferably, a tension spring is further installed on the translation slider, and the tension spring is located between the two groups of translation sliders. The other end of the tension spring is fixed on the base, and the tension spring applies tension to the translation slider.

[0012] Preferably, an X-axis distance sensor and a Y-axis distance sensor are further included for measuring the moving distance of the translation stage; the detection end of the X-axis distance sensor is arranged along the X-axis and faces the translation stage, and the detection end of the Y-axis distance sensor is arranged along the Y-axis and faces the translation stage.

[0013] Preferably, the translation slider is provided with a baffle extending along the Y-axis direction; and further comprises an origin sensor and a limit sensor for performing position detection in cooperation with the baffle.

[0014] Preferably, the origin sensor and the limit sensor are both slot-type switch sensors.

[0015] The utility model also provides a movable aperture mechanism, comprising an aperture assembly and the above-mentioned parallel drive displacement mechanism, wherein the aperture assembly is mounted on the displacement platform.

[0016] Preferably, the translation stage is mounted on a support rod via a connector, a bellows is sealed outside the support rod, the aperture assembly is located in the vacuum chamber and connected to the support rod, and the negative pressure in the vacuum chamber sucks the translation stage tightly through the bellows and the support rod.

[0017] Preferably, the aperture assembly includes an aperture, an aperture seat and a pressing plate, the aperture seat is installed on the end of the support rod, a strip hole is provided on the aperture seat, the aperture is fixed above the strip hole by the pressing plate, and a through hole adapted to the strip hole is provided on the pressing plate.

[0018] The beneficial effects of the present invention are:

[0019] In response to the need for severe imbalance in the travel in the X and Y directions, the utility model abandons the traditional method of superimposing the X and Y translation stages and adopts a layout of opposing dual motors, which transmit the power to the translation stage through a crank connecting rod, resulting in a simpler and more reliable structure.

[0020] With the combined motion of the dual motors, the translation stage can move in both the X / Y directions and along specific curves. The stage can be positioned away from the motor's operating area, expanding its practical application range. The motion range varies with the length of the connecting rod and fixed rod, and can be selected based on actual needs.

[0021] The utility model adds X-axis and Y-axis distance sensors to directly measure the end displacement stage, avoiding the transmission of errors (such as gap and creep), completing the closed-loop control system, and improving the positioning accuracy of the end actuator;

[0022] The movable aperture mechanism uses a vacuum chamber, a bellows, a linear slide, and a translation slider to tighten the translation stage using vacuum suction, eliminating motion gaps and improving vacuum environment compatibility and working stability.

[0023] Compared with the prior art, the utility model has a simple structure, diverse movement modes, high positioning accuracy, and a wide range of applications. It is particularly suitable for application scenarios that require large differences in travel in different directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0025] Figure 1 It is a top view of the parallel drive displacement mechanism of the utility model;

[0026] Figure 2 It is a schematic diagram of another working state of the utility model;

[0027] Figure 3 This is a schematic diagram of the matching structure of the baffle and the origin sensor of the utility model;

[0028] Figure 4 It is a top view of the movable aperture mechanism;

[0029] Figure 5This is an exploded diagram of the aperture assembly;

[0030] Figure 6 is with Figure 1 The corresponding simplified model schematic diagram;

[0031] Figure 7a This is a schematic diagram of the initial state of the two sets of motors in the parallel drive displacement mechanism moving in opposite directions;

[0032] Figure 7b It is a schematic diagram of the changing process of the opposite motion of two groups of motors in a parallel drive displacement mechanism;

[0033] Figure 8a This is a schematic diagram of the initial state of the two groups of motors in the parallel drive displacement mechanism moving in the same direction;

[0034] Figure 8b It is a schematic diagram of the changing process of the two groups of motors in the parallel drive displacement mechanism moving in the same direction;

[0035] Figure 9a Schematic diagram of the initial state of the right motor motion of the parallel drive displacement mechanism;

[0036] Figure 9b It is a schematic diagram of the changing process of the right motor movement of the parallel drive displacement mechanism.

[0037] The following are marked in the figure:

[0038] 10. Drive component 1; 11. Linear slide; 12. Translation slider; 13. Connecting rod unit; 131. Connecting rod; 14. Translation stage; 15. Compression spring; 16. Tension spring; 17. Baffle; 18. Screw; 19. Connector; 20. Drive component 2; 30. Base; 40. X-axis distance sensor; 50. Y-axis distance sensor; 60. Origin sensor; 70. Limit sensor; 80. Vacuum chamber; 81. Bellows; 82. Support rod; 821. Flange; 90. Aperture assembly; 91. Aperture; 92. Aperture seat; 921. Slot; 922. Strip hole; 93. Pressing piece; 931. Through hole. DETAILED DESCRIPTION

[0039] like Figures 1 to 6 As shown, a parallel drive displacement mechanism includes drive assembly 10 and drive assembly 20 arranged opposite each other. Drive assembly 10 and drive assembly 20 each include a linear slide 11, a translation slider 12 located at the output end of linear slide 11, and a connecting rod unit 13 hingedly connected to translation slider 12. The proximal ends of both connecting rod units 13 are rotatably connected to a displacement stage 14. The "proximal end" refers to the ends of the two connecting rod units 13 that are close to each other.

[0040] Please refer to Figure 1 、 Figure 2, drive component 1 10 and drive component 2 20 are relatively arranged on the base 30, and the two sets of linear slides 11 are respectively fixed on both sides of the base 30. In a preferred embodiment, the linear slide 11 uses a through-axis motor. The through-axis motor is a well-known technology and its internal structure will not be described in detail. A compression spring 15 is installed on the screw rod 18 of the through-axis motor. The compression spring 15 is located between the through-axis motor and the translation slider 12, and is used to apply thrust to the translation slider 12 to eliminate the X-axial clearance generated by the motor on the translation slider 12, that is, the axial shaking clearance of the motor. The through-axis motor is connected to the control system through a power connection line. The control system can accurately control the speed and direction of the through-axis motor, thereby controlling the moving speed and direction of the translation slider 12.

[0041] A tension spring 16 is also mounted on the translation slider 12. The other end of the tension spring 16 is fixed to the base 30. Positioned between the two drive assembly groups, the tension spring 16 applies tension to the corresponding translation slider 12. The tension spring 16, working in conjunction with the compression spring 15, eliminates backlash during the movement of the translation slider 12, improving displacement accuracy. A slide rail is mounted on the base along the X-axis. A groove mates with the rail at the bottom of the translation slider 12, ensuring smooth movement along the axial direction of the linear slide 11.

[0042] The connecting rod unit 13 includes two parallel connecting rods 131, the ends of which are respectively hinged to the translation slider 12 and the displacement stage 14 to form a parallelogram component. Specifically, a fixed rod can be installed on the translation slider 12 along the Y-axis direction, and the end of the connecting rod 131 is hinged to the fixed rod via a rotating shaft. The parallelogram component can ensure that the displacement stage 14 remains horizontal during movement and does not tilt. The connecting rod is made of lightweight, high-strength material to reduce inertia and improve response speed. High-precision bearings are used at the connection between the connecting rod, the translation slider 12, and the displacement stage 14 to reduce friction and improve movement accuracy.

[0043] The translation platform 14 is located between the two linkage units 13 and is connected to them via an articulated joint. The translation platform 14 has mounting holes for mounting equipment that requires precise positioning. The translation platform 14 is made of lightweight, high-strength materials to reduce inertia and improve response speed.

[0044] The simplified model of this organization is as follows Figure 6 As shown in the figure, the coordinates of the translation stage can be obtained according to the different motor distances. Point O is the starting point of the movement of the drive component 10 on the left; point K is the starting point of the movement of the drive component 20 on the right; X1 and X2 are the relative movement distances of the drive components on both sides respectively; e is the length of the connecting rod, θ is the angle between the connecting rod and the X-axis, and the final coordinates of the displacement point are (M, N).

[0045] Please refer to Figure 7a and Figure 7b In one embodiment, two linear slides 11 drive two translation blocks 12 in opposite directions at equal speeds, thereby changing the Y coordinate of the translation stage 14. Specifically, when the translation block 12 of drive assembly 10 moves toward drive assembly 2 20, and simultaneously, the translation block 12 of drive assembly 20 moves toward drive assembly 1 10, the translation stage 14 moves along the Y axis. The distance of movement is determined by the distances of the two translation blocks 12, and the direction of movement is determined by the directions of movement of the two translation blocks 12.

[0046] Please refer to Figure 8a and Figure 8b In a specific embodiment, two groups of linear slides 11 drive two groups of translation sliders 12 to move in the same direction and at equal speeds, thereby changing the X-coordinate value of the translation stage 14. That is, when the translation sliders 12 of drive component 10 and drive component 2 20 move in the same direction at the same time, the translation stage 14 moves along the X-axis direction. The moving distance is determined by the moving distance of the two groups of translation sliders 12, and the moving direction is determined by the moving direction of the two groups of translation sliders 12. For example, when it is necessary to translate the translation stage to the right, first, in the preparatory stage, start the linear slide 11 on the right side, so that its translation slider 12 moves to the left to the left side of the screw rod 18, thereby reserving space for the translation slider 12 to move to the right. Subsequently, the left and right groups of linear slides 11 are started at the same time, driving the two groups of translation sliders 12 to move synchronously to the right. If it is necessary to translate the translation stage to the left, the operation process is similar and will not be repeated here.

[0047] Please refer to Figure 9a and Figure 9b In one embodiment, a set of linear slides 11 drives the translational sliders 12, causing the translation stage 14 to move in an arc. Specifically, when only the translational sliders 12 of one drive assembly move, the translation stage 14 moves in an arc about the hinge point of the other set of linkage units 13. The radius of this arc is determined by the length of the linkage units, while the angle of this arc is determined by the distance the translational sliders 12 move.

[0048] For example, if the left motor is stationary and the right motor is moving, let X1=0, M=e*sinθ, N=e*cosθ, that is, M²+N²=e²*(sin²θ+cos²θ). Since sin²θ+cos²θ=1, no matter how M and N change, M²+N²=e². Figure 6 Because the hinge point at the lower end of the left connecting rod is fixed and M²+N²=e² is satisfied, the connecting rod and the translation platform 14 can only move in a circular motion.

[0049] The above working methods can be used individually or in combination according to actual needs.

[0050] The parallel-drive displacement mechanism also includes an X-axis distance sensor 40 and a Y-axis distance sensor 50 for measuring the travel distance of the displacement stage 14. The detection end of the X-axis distance sensor 40 is arranged along the X-axis and faces the displacement stage 14, and the detection end of the Y-axis distance sensor 50 is arranged along the Y-axis and faces the displacement stage 14. In an optional embodiment, both the X-axis distance sensor 40 and the Y-axis distance sensor 50 are high-precision laser displacement sensors with a measurement accuracy of up to micrometers. The sensors are connected to the control system via a data cable, providing real-time feedback on the position information of the displacement stage 14, forming a closed-loop control system and improving positioning accuracy. However, the type of distance sensor of the present invention is not limited to this.

[0051] like Figure 1-3 As shown, the translation slider 12 is provided with a baffle 17 along the Y-axis direction and also includes an origin sensor 60 and a limit sensor 70 that cooperate with the baffle 17 for position detection. The origin sensor 60 is used to detect whether the translation slider 12 is in its initial position, and the limit sensor 70 is used to detect whether the translation slider 12 has exceeded the safe range of motion. Both the origin sensor 60 and the limit sensor 70 are slot-type switch sensors. When the baffle 17 enters the sensor slot, the sensor outputs a signal, which the control system uses to determine the position of the translation slider 12.

[0052] Please refer to Figure 3 The slot switch sensor consists of a transmitter and a receiver. The transmitter emits infrared light, and the receiver receives it. When the baffle 17 enters the slot, it blocks the infrared light, preventing the receiver from receiving it. The output signal changes, and the control system determines the position of the baffle 17 based on the signal change. The slot switch sensor has a fast response speed and high reliability, making it suitable for position detection.

[0053] The present invention incorporates X-axis and Y-axis distance sensors in the end-of-pivot detection mechanism, enabling real-time detection of the coordinates of the displacement points of the stage 14. For example, the drive assemblies on either side first drive the stage 14 in opposite directions by the same distance (X1 = X2), changing and determining the height of the stage 14, i.e., the coordinate value of point N. The sensors then detect the stage coordinates (M, N). The drive assemblies on both sides then drive the stage 14 in the same direction (X1 + X2 remains constant during this movement), and the coordinate value of point M is detected and determined. The use of distance sensors eliminates tedious coordinate calculations, directly obtaining the coordinates of the final execution point and avoiding systematic errors (such as backlash and creep).

[0054] Example 2

[0055] Please refer to Figure 4 、 Figure 5 A movable aperture mechanism includes an aperture assembly 90 and the parallel drive displacement mechanism described in Example 1, and the aperture assembly 90 is installed on the displacement platform 14.

[0056] The translation stage 14 is mounted on a support rod 82 via a connector 19. A bellows 81 is sheathed around the support rod 82. One end of the support rod 82 and bellows 81 extends into the vacuum chamber 80. The end of the support rod 82 located within the vacuum chamber has an annular flange 821, to which the front end of the bellows 81 is sealed and secured. The rear end of the bellows 81 is sealed to the vacuum chamber via the flange, ensuring a vacuum environment within the chamber. The bellows 81 is also sealed at both ends, providing excellent elasticity and airtightness. Because the interior of the bellows 81 is at positive pressure (the positive pressure stems from the fact that, after the bellows' ends are sealed, the interior is open to the atmosphere, resulting in a positive pressure relative to the vacuum chamber environment), and because the bellows 81 is placed in a vacuum environment, the negative pressure within the vacuum chamber 80 creates a pressure differential between the interior and exterior of the bellows 81. This suction force draws the translation stage 14 forward through the bellows 81 and support rod 82. This suction eliminates the Y-axis play in the motor, thereby eliminating radial play.

[0057] The negative pressure in the vacuum chamber 80 is generated by a vacuum pump, and the negative pressure value can be adjusted as needed. In an optional manner, the vacuum chamber 80 is made of aluminum alloy material, which has good airtightness and lightweight properties.

[0058] The aperture assembly 90 is mounted on the support rod 82. Figure 5 As shown, the aperture assembly 90 is used to control the shape and size of the light beam. The position of the aperture can be precisely adjusted via a parallel-driven displacement mechanism. Aperture assembly 90 comprises an aperture 91, an aperture seat 92, and a pressure plate 93. Aperture seat 92 is fixedly connected to a support rod. Aperture seat 92 is provided with a slot 921 for mounting aperture 91. Slot 921 defines a strip-shaped hole 922. The aperture is secured to the slot above the strip-shaped hole 922 by pressure plate 93. Pressure plate 93 also includes a through-hole 931 that mates with the strip-shaped hole 922. Aperture 91 is provided with at least one row of small holes for the electron beam to pass through. The holes can be arranged side by side or in a specific curve, allowing for more holes to be added within the same area, thus extending the life of the aperture.

[0059] The strip-shaped apertures 922 provided on the aperture holder 92 allow the electron beam to pass through the various small holes in the aperture. The length and width of the strip-shaped apertures 922 are determined by the aperture size. The aperture 91 is made of a metal material, which has excellent light-shielding properties and heat resistance. Of course, the above description is merely illustrative, and this application does not impose any specific restrictions on the material of the aperture assembly 90. The shape and size of the aperture are determined by the requirements of the optical system.

[0060] The pressing piece 93 is fixedly connected to the aperture seat 92 by screws, fixing the aperture 91 in the clamping groove 921. The through hole 931 provided on the pressing piece 93 is adapted to the strip hole 922, and the area of ​​the through hole 931 covers the effective light hole of the aperture.

[0061] When the movable aperture mechanism is in operation, the parallel drive mechanism drives the translation stage 14, which in turn drives the support rods and aperture assembly 90 via connector 19, thereby achieving precise adjustment of the aperture position. The aperture 91 can move in the X- and Y-axis directions, as well as in an arc, to meet the needs of different optical systems.

[0062] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will be able to modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A parallel drive displacement mechanism, characterized in that: It comprises a driving component 1 and a driving component 2 which are arranged opposite to each other, wherein the driving component 1 and the driving component 2 both comprise a linear slide, a translation slider located at the output end of the linear slide, and a connecting rod unit hinged to the translation slider, and the proximal ends of the two groups of the connecting rod units are rotatably connected to a translation stage; the two groups of the linear slides respectively drive the two groups of the translation sliders to move in opposite directions at equal speeds, thereby changing the Y coordinate value of the translation stage; the two groups of the linear slides respectively drive the two groups of the translation sliders to move in the same direction at equal speeds, thereby changing the X coordinate value of the translation stage; one group of the linear slides does not move, and the other group of the linear slides drives the translation sliders to move, causing the translation stage to move in an arc.

2. The parallel drive displacement mechanism according to claim 1, characterized in that: The connecting rod unit includes two connecting rods arranged in parallel, and the two ends of the connecting rods are respectively hinged to the translation slider and the displacement platform to form a parallelogram component.

3. The parallel drive displacement mechanism according to claim 1, characterized in that: The linear slide comprises a through-axis motor, a compression spring is installed on the lead screw of the through-axis motor, and the compression spring is located between the through-axis motor and the translation slider, and is used to apply thrust to the translation slider.

4. The parallel drive displacement mechanism according to claim 1, characterized in that: A tension spring is also installed on the translation slider. The tension spring is located between the two groups of translation sliders. The other end of the tension spring is fixed on the base. The tension spring applies tension to the translation slider.

5. The parallel drive displacement mechanism according to claim 1, characterized in that: It also includes an X-axis distance sensor and a Y-axis distance sensor for measuring the moving distance of the translation stage; the detection end of the X-axis distance sensor is arranged along the X-axis and faces the translation stage, and the detection end of the Y-axis distance sensor is arranged along the Y-axis and faces the translation stage.

6. The parallel drive displacement mechanism according to claim 1, characterized in that: The translation slider is provided with a blocking piece extending along the Y-axis direction; and further comprises an origin sensor and a limit sensor which cooperate with the blocking piece to perform position detection.

7. The parallel drive displacement mechanism according to claim 6, characterized in that: The origin sensor and the limit sensor are both slot-type switch sensors.

8. A movable aperture mechanism, characterized in that: The device comprises an aperture assembly and the parallel-driven displacement mechanism according to any one of claims 1 to 7, wherein the aperture assembly is mounted on the displacement stage.

9. The movable aperture mechanism according to claim 8, wherein: The translation stage is installed with a support rod through a connector, and a bellows is provided on the outer sealing sleeve of the support rod. The aperture assembly is located in the vacuum chamber and connected to the support rod. The negative pressure in the vacuum chamber sucks the translation stage tightly through the bellows and the support rod.

10. The movable aperture mechanism according to claim 9, wherein: The aperture assembly includes an aperture, an aperture seat and a pressing plate. The aperture seat is installed at the end of the support rod. A strip hole is provided on the aperture seat. The aperture is fixed above the strip hole by the pressing plate. A through hole adapted to the strip hole is provided on the pressing plate.

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