Bridge differential flexible displacement reduction mechanism

Abstract

The application discloses a bridge type differential flexible displacement reduction mechanism, which comprises a fixed half-bridge flexible module, a movable half-bridge flexible module, rigid connecting blocks and a driver, wherein the fixed half-bridge flexible module and the movable half-bridge flexible module are arranged between the two rigid connecting blocks to form a ring-shaped frame, and the driver is arranged between the two rigid connecting blocks in the ring-shaped frame; the bending directions of the fixed half-bridge flexible module and the movable half-bridge flexible module are the same; the differential superposition of displacement is realized by the combination of the two half-bridge flexible modules, a large displacement reduction ratio can be obtained, and the resolution and the accuracy of movement are greatly improved; the bridge type differential flexible displacement reduction mechanism can be matched with a macro-motion platform to realize large-range and ultra-high-precision movement positioning.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of precision driving and transmission, and particularly relates to a bridge type differential flexible displacement reduction mechanism. BACKGROUND

[0002] Nanometer positioning technology is the basis for realizing nanometer control and nanometer measurement. Generally, piezoelectric stack drivers are directly used to drive positioning, or piezoelectric stack drivers are used as the basis to further amplify displacement by using displacement amplification mechanisms (such as bridge type or lever type), which can only achieve a movement precision of tens of nanometers or even hundreds of nanometers.

[0003] With the development of science and technology, the semiconductor technology, aerospace technology, optical and optoelectronic engineering, and biological engineering fields have put forward higher and higher requirements for positioning precision. For example, the worktable with ultra-high positioning precision is one of the core components of a photoetching machine, and its movement precision directly affects the quality of the silicon wafer photoetched. In order to meet the process technology requirements of the latest generation of chips, the movement precision needs to reach 2 nanometers under high-speed movement. SUMMARY

[0004] The present application aims to provide a bridge type differential flexible displacement reduction mechanism to solve the above problems.

[0005] To achieve the above purpose, the present application adopts the following technical solutions:

[0006] A bridge type differential flexible displacement reduction mechanism comprises a fixed half-bridge flexible module, a movable half-bridge flexible module, a rigid connecting block, and a driver. The fixed half-bridge flexible module and the movable half-bridge flexible module are arranged between the two rigid connecting blocks to form a ring-shaped frame, and the driver is arranged between the two rigid connecting blocks in the ring-shaped frame. The bending directions of the fixed half-bridge flexible module and the movable half-bridge flexible module are the same.

[0007] The fixed half-bridge flexible module and the movable half-bridge flexible module have the same structure and each comprise a middle block and a flexible branch. One or more flexible branches are arranged on both sides of the middle block, and the number of flexible branches on both sides of the middle block is the same or different.

[0008] Further, the flexible branch is a concentrated flexibility type branch or a distributed flexibility type branch.

[0009] Further, the two ends of the concentrated flexibility type branch are symmetrically provided with notches on both sides, and a flexible hinge is formed on the inner side of the notches.

[0010] Further, the distributed flexibility type branch is a whole flexible beam, and the flexible beam is a long beam or a spring piece.

[0011] Further, the fixed half-bridge flexible module and the active half-bridge flexible module are arranged in the same direction, and θ1 and θ2 are respectively the angles of the horizontal line to the single-side branch chain in the fixed half-bridge flexible module and the single-side branch chain in the active half-bridge flexible module in the counterclockwise direction, θ1 and θ2 should be in the range of 0-90° at the same time, or in the range of 90°-180° at the same time.

[0012] Further, the middle block of the fixed half-bridge flexible module is connected with the rack, and the middle block of the active half-bridge flexible module is the output end of the whole mechanism.

[0013] Further, the driver is fixedly connected with the two rigid connection blocks at two ends, and the driver provides linear input to make the two rigid connection blocks move away or approach.

[0014] Further, the driver is a piezoelectric stack driver, a magnetostrictive driver or a linear voice coil motor.

[0015] In addition, the application also discloses a bridge type differential flexible displacement reduction mechanism, which is characterized by comprising a fixed half-bridge flexible module (1), an active half-bridge flexible module (2), a rigid connection block (3) and a driver (4); the fixed half-bridge flexible module (1) and the active half-bridge flexible module (2) are arranged between the two rigid connection blocks (3) to form a ring-shaped frame, and the driver (4) is arranged between the two rigid connection blocks (3) in the ring-shaped frame; the bending directions of the fixed half-bridge flexible module (1) and the active half-bridge flexible module (2) are the same; the two half-bridge flexible modules are arranged in the same direction to generate differential motion.

[0016] The fixed half-bridge flexible module (1) and the active half-bridge flexible module (2) are the same in structure and each comprise a middle section and flexible branch chains (6), one or more flexible branch chains (6) are arranged on the two sides of the middle block, and the number of the flexible branch chains (6) on the two sides of the middle section is the same or different.

[0017] Further, the middle block (5) in the middle of the fixed half-bridge flexible module (1) is connected with the rack, and the middle of the active half-bridge flexible module (2) is an output section (7), and the output section (7) is the output end of the whole mechanism.

[0018] In addition, the application also discloses a bridge type differential flexible displacement reduction mechanism, which comprises:

[0019] two fixed half-bridge flexible modules (1) and two active half-bridge flexible modules (2), two rigid connection blocks (3), a middle block (5), an output block (7) and a driver (4) between the two rigid connection blocks (3);

[0020] Along the circumference of the displacement reduction mechanism, the first fixed half-bridge flexible module (1), the first rigid connecting block (3), the first movable half-bridge flexible module (2), the output block (7), the second movable half-bridge flexible module (2), the second rigid connecting block (3), the second fixed half-bridge flexible module (1), and the intermediate block (5) form a movable outer frame.

[0021] For the fixed half-bridge flexible module (1) and the movable half-bridge flexible module (2) connected to a rigid connecting block (3), wherein:

[0022] One end of the fixed half-bridge flexible module (1) and the movable half-bridge flexible module (2) is connected to the two ends of the rigid connecting block (3), respectively.

[0023] The other end of the fixed half-bridge flexible module (1) is connected to the intermediate block (5).

[0024] The other end of the movable half-bridge flexible module (2) is connected to the output block (7).

[0025] Compared with the prior art, the present application has the following technical effects:

[0026] The present application utilizes the combination of two half-bridge flexible modules to realize differential superposition of displacement, which can obtain a large displacement reduction ratio, thereby greatly improving the resolution and accuracy of motion.

[0027] The bridge differential flexible displacement reduction mechanism can be combined with a macro-motion platform to realize large-range and ultra-high-precision motion positioning.

[0028] The body structure of the present application can be integrally machined, and the structure is simple and does not need to be assembled. DETAILED DESCRIPTION

[0029] Figure 1 It is a concentrated flexibility structure schematic diagram of the present application;

[0030] Figure 2 It is a concentrated flexibility motion schematic diagram of the present application;

[0031] Figure 3 It is a mixed structure schematic diagram of the present application;

[0032] Figure 4 It is a distributed flexibility structure schematic diagram of the present application;

[0033] Figure 5 It is a just-constrained concentrated flexibility structure schematic diagram of the present application;

[0034] Figure 6 It is an over-constrained concentrated flexibility structure schematic diagram of the present application;

[0035] Figure 7 It is a just-constrained distributed flexibility structure schematic diagram of the present application;

[0036] Figure 8 This is a schematic diagram of the over-constrained distributed flexibility structure of the present invention. Detailed Implementation

[0037] The present invention will be further described below with reference to the accompanying drawings and various embodiments.

[0038] Please see Figures 1 to 8 In particular, with Figure 1 For example, in one embodiment, the present invention discloses a bridge-type differential flexible displacement reduction mechanism, characterized in that it includes a fixed half-bridge flexible module 1, a movable half-bridge flexible module 2, a rigid connecting block 3, and a driver 4; the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 are both disposed between two rigid connecting blocks 3 to form an annular frame, and the driver 4 is disposed between two rigid connecting blocks 3 within the annular frame; the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 have the same bending direction;

[0039] The fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 have the same structure, both including a middle block 5 and flexible branches 6. One or more flexible branches 6 are respectively arranged on both sides of the middle block 5, and the number of flexible branches 6 on both sides of the middle block 5 may be the same or different.

[0040] It is understood that the two half-bridge flexible modules are arranged in the same direction to generate differential motion. In another embodiment, the bridge-type differential flexible displacement reduction mechanism includes a fixed half-bridge flexible module, a movable half-bridge flexible module, a rigid connecting block, and a piezoelectric actuator.

[0041] In another embodiment, the two half-bridge flexible modules can be either concentrated flexibility or distributed flexibility (for the concentrated flexibility structure, they are connected to the fixed platform and the connecting block respectively through two slotted flexible hinges).

[0042] In another embodiment, the middle part of the fixed half-bridge flexible module is fixed, and both ends are connected to rigid connecting blocks.

[0043] In another embodiment, the piezoelectric actuator is fixed at both ends to a rigid connecting block, and lateral displacement is input to the rigid connecting block.

[0044] Furthermore, the other end of the rigid connecting block is connected to both ends of the flexible half-bridge module.

[0045] In another embodiment, the middle block of the active half-bridge flexible module serves as the output end, outputting the reduced displacement outward.

[0046] The working principle of this invention is as follows: further combining Figure 2As shown, first, the driver 4 inside the bridge mechanism is pre-powered, the driver generates an input displacement Δx in the X direction, the input displacement is transmitted to the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 through the rigid connecting block 3, the displacement is converted by the fixed half-bridge flexible module 1 and output in the Y direction, and the displacement is converted by the movable half-bridge flexible module 2 and output in the opposite direction of the Y direction, the superposition of the two output displacements obtains a small output displacement, and the reduction of the input displacement is realized. Other differential displacement reduction mechanisms (such as Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 and Figure 8 work in the same way as the concentrated flexibility differential displacement reduction mechanism of Figure 1 .

[0047] Further, the rigid connecting block is provided with a transverse displacement Δx by a linear driver (such as a piezoelectric stack driver) to push the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2.

[0048] For the fixed half-bridge flexible module, when the driver inputs a horizontal displacement of 2Δx, the two rigid blocks not only produce a horizontal displacement Δx, but also produce a downward displacement Δy1 in the vertical direction, Δy1≈Δx / tan(θ1).

[0049] For the movable half-bridge flexible module, the transverse displacement Δx of the two rigid blocks makes the output end of the mechanism produce a longitudinal displacement Δy2 in the vertical direction relative to the two rigid blocks, Δy2≈Δx / tan(θ2).

[0050] The output end of the whole mechanism is the middle block of the movable half-bridge flexible module, and the output displacement of the middle block relative to the base is Δy=Δy2-Δy1, that is, by canceling the displacements of the two half-bridge flexible modules, a large-scale reduction of the input displacement of the driver can be realized. By changing the design parameters of the two half-bridge flexible modules, any scale of displacement reduction can be obtained (for example, in the extreme case, when the design parameters of the two bridge flexible modules are completely the same, the output displacement of the whole mechanism is 0, which means infinite reduction ratio).

[0051] In another embodiment, the two concentrated flexibility (notched flexible hinges) half-bridge flexible modules can be replaced by distributed flexibility (long beams or spring leaves) half-bridge modules in whole or in part.

[0052] Other embodiments are as follows:

[0053] In combination with Figure 1In the shown embodiment, in order to make the structure more compact and simple, and also to reduce the weight of the structure, one concentrated flexibility type flexible branch is connected to each end of the middle block in the two half-bridge flexible modules. In the working process, by changing the voltage on the piezoelectric stack driver 4, the piezoelectric driver 4 generates X direction displacement, when the voltage increases, the piezoelectric stack driver 4 generates X direction elongation movement, when the voltage decreases, the piezoelectric stack driver 4 generates X direction contraction movement. The X direction displacement drives the two rigid connection blocks 3 connected with the piezoelectric stack driver to generate X direction displacement, which in turn drives the notched flexible hinge in the fixed half-bridge flexible amplification module 1 and the movable half-bridge flexible amplification module 2 connected with the rigid connection block to generate deformation, so that the two half-bridge flexible modules generate opposite Y direction displacements, which are superimposed and offset after mutual superposition to output a very small Y direction displacement on the middle block 5 of the movable half-bridge flexible module.

[0054] In another embodiment, the fixed half-bridge flexible module and the movable half-bridge flexible module have the same structure, and each includes a middle section and flexible branches, one or more flexible branches are arranged on both sides of the middle section, and the number of flexible branches on both sides of the middle section is the same or different.

[0055] Further, the middle fixed section of the fixed half-bridge flexible module is connected to the rack, and the middle of the movable half-bridge flexible module is an output section, which is the output end of the entire mechanism.

[0056] In another embodiment, the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 have the same structure, and each includes a middle section and flexible branches 6, one or more flexible branches 6 are arranged on both sides of the middle section, and the number of flexible branches 6 on both sides of the middle section is the same or different.

[0057] In another embodiment, the middle section of the fixed half-bridge flexible module is a middle block 5, and both ends are connected to rigid connection blocks.

[0058] In another embodiment, the middle section of the movable half-bridge flexible module is an output section 7 that outputs the reduced displacement outward.

[0059] Figure 1 A plan view of a bridge differential displacement reduction mechanism is shown, which also discloses the following scheme:

[0060] A bridge differential flexible displacement reduction mechanism, comprising:

[0061] Two fixed half-bridge flexible modules (1) and two movable half-bridge flexible modules (2), two rigid connection blocks (3), a middle block (5), an output block (7), and a driver (4) between the two rigid connection blocks (3);

[0062] Along the circumference of the displacement reduction mechanism, the first fixed half-bridge flexible module (1), the first rigid connecting block (3), the first movable half-bridge flexible module (2), the output block (7), the second movable half-bridge flexible module (2), the second rigid connecting block (3), the second fixed half-bridge flexible module (1), and the intermediate block (5) form a movable outer frame.

[0063] For the fixed half-bridge flexible module (1) and the movable half-bridge flexible module (2) connected to a rigid connecting block (3), wherein:

[0064] One end of the fixed half-bridge flexible module (1) and the movable half-bridge flexible module (2) is connected to the two ends of the rigid connecting block (3), respectively.

[0065] The other end of the fixed half-bridge flexible module (1) is connected to the intermediate block (5).

[0066] The other end of the movable half-bridge flexible module (2) is connected to the output block (7).

[0067] For example, one end of the driver is connected between the two ends of the rigid connecting block (3); the driver can be directly connected to the rigid connecting block, or can be connected to the rigid connecting block via a ball or the like.

[0068] Figure 1 The illustrated bridge differential displacement reduction mechanism is composed of plate materials, including a fixed half-bridge flexible module 1, a movable half-bridge flexible module 2, a rigid connecting block 3, and a driver 4. The flexible branch 6 of the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 is a bridge mechanism. The number of flexible branches 6 in the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 can be determined according to the flexibility and rotational stiffness requirements of the displacement reduction mechanism.

[0069] Figure 1 The illustrated fixed half-bridge flexible module 1 includes two flexible branches 6 and an intermediate block 5, and the two flexible branches 6 are symmetrically arranged at the two ends of the intermediate block 5. The movable half-bridge flexible module 2 includes two flexible branches 6 and an output section 7, and the two flexible branches 6 are symmetrically arranged at the two ends of the output section 7. The intermediate block 5 of the fixed half-bridge flexible module 1 is connected to the ground, and the output section 7 of the movable half-bridge flexible module 2 is the output end of the entire mechanism.

[0070] As shown in Figure 1 The driver 4 is fixedly connected to the two rigid connecting blocks 3, and the driver 4 provides linear input to make the two rigid connecting blocks 3 move outward or contract inward. As shown in Figure 1 The flexible branches 6 in the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 are of the concentrated flexibility type (notched flexible hinge). The flexible hinges at the two ends of the concentrated flexible type branch can be arranged horizontally, vertically, or along the branch. Figure 1In the middle, the direction of the flexible hinge is along the direction of the flexible branch.

[0071] Figure 2 is a plan view of a possible bridge differential reduction mechanism in motion according to the present application. First, voltage is applied to the driver 4. The driver 4 generates an input displacement 2Δx in the X direction, which is transmitted to the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 through the rigid connecting blocks 3. For the fixed half-bridge flexible module 1, when the input displacement of the driver 4 is equal to 2Δx, the rigid connecting blocks 3 on both sides not only generate a horizontal displacement, but also generate a vertical displacement Δy1(Δy1≈-Δx / tan(θ1)) relative to the ground. For the movable half-bridge flexible module 2, the input displacement 2Δx of the rigid connecting blocks 3 causes the output segment 7 to generate a vertical displacement Δy2(Δy2≈Δx / tan(θ2)) relative to the rigid connecting blocks 3. The output displacement Δy of the entire mechanism relative to the ground is Δy2-Δy1. By changing the values of θ1 and θ2, the reduction ratio of any bridge differential displacement reduction mechanism can be obtained (for example, in the extreme case, when θ1 and θ2 are exactly the same, the output displacement Δy is 0).

[0072] A preferred embodiment of the present application: the flexible branches 6 of the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 can be completely or partially replaced by distributed flexible beams. Figure 3 and Figure 4 shows two examples of differential displacement reduction mechanisms. As shown in Figure 3 , the flexible branches of the fixed half-bridge flexible module 1 are replaced by distributed flexible beams. The flexible branches 6 of the fixed half-bridge flexible module 1 and the movable half-bridge flexible module 2 are both replaced by distributed flexible beams.

[0073] Another preferred embodiment of the present application: the number of flexible branches 6 on both sides of the intermediate block 5 (or the output segment 7) can be different to increase the stiffness of the mechanism. Figure 5 and Figure 6 are two examples of differential displacement reduction mechanisms. As shown in Figure 5 , the number of flexible branches 6 on both sides of the intermediate block 5 is different, 1 on the left and 2 on the right. The number of flexible branches 6 on both sides of the output segment 7 is also different, 2 on the left and 1 on the right. As shown in Figure 6 , the number of flexible branches 6 on both sides of the intermediate block 5 is the same, 2 flexible branches on each side. There are also the same number of flexible branches on both sides of the intermediate block 5, two on each side. The number of flexible branches 6 is not limited to one or two on one side, but can be more.

[0074] Figure 7 is a plan view of a distributed flexible displacement reduction mechanism with different numbers of flexible branches 6 on both sides of the intermediate block 5. As shown in Figure 7As shown, the middle block 5 has two flexible beams on the left side and one flexible beam on the right side. The output section 7 also has two flexible beams on the left side and one flexible beam on the right side. As shown in FIG. 2, the middle block 5 has three flexible beams on each side. The output section 7 also has three flexible beams on each side. Figure 8

[0075] In combination with all the above figures, the displacement reduction mechanism disclosed in the present application has the following characteristics:

[0076] The middle block 5 of the displacement reduction mechanism is equivalent to a fixed section and is a one-piece structure rather than a half-frame structure composed of multiple different shapes. The rigid connecting block is outside the flexible sections L1 and L2.

[0077] The displacement reduction mechanism is configured as follows:

[0078] From either end of the fixed section, there are, in order, the fixed section, the flexible section L1, the rigid connecting block 3, the flexible section L2, and the output section output. The displacement reduction mechanism disclosed in the present application adopts a bridge mechanism, which can effectively reduce the volume of the output end, improve the output stiffness, and reduce the deformation of the output end, and is suitable for situations where the end load is large.

[0079] It can be understood that, for those skilled in the art, it is known that the various displacement reduction mechanisms disclosed in the embodiments can be made of a plate as a whole, or can be disassembled into multiple parts for machining and assembly, and are not limited to any material or formation method. The driver can be exemplarily selected as a linear driver, such as a PZT piezoelectric ceramic driver. The figures shown in all the figures are only schematic diagrams and do not represent the size ratio, relative position, shape, etc. of the components in the various displacement reduction mechanisms, which are completely limited by the figures. For example, the outer frame is not limited to a polygonal frame. In addition, in combination with the figures, it can be found that, in addition to the above-mentioned embodiments, the technical solutions disclosed in the present application all have the characteristic of symmetry in structure. Figure 5 、 Figure 7

[0080] In summary, the bridge differential displacement reduction mechanism of the present application can achieve large reduction ratio and high-precision displacement transmission. Compared with the traditional displacement amplification mechanism, the present application can at least improve one order of magnitude, for example, to 2 nanometer level or even higher.

[0081] Although the preferred embodiments of the present application have been described above in combination with the figures, the present application is not limited to the above-mentioned specific embodiments, which are only illustrative and not limiting. Those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims, which all belong to the protection scope of the present application.​​

Claims

1. A bridge differential flexible displacement reduction mechanism characterized by, The bridge differential flexible displacement reduction mechanism comprises fixed half-bridge flexible modules (1), movable half-bridge flexible modules (2), rigid connecting blocks (3) and drivers (4); the fixed half-bridge flexible modules (1) and the movable half-bridge flexible modules (2) are arranged between the two rigid connecting blocks (3) to form a ring-shaped frame, and the drivers (4) are arranged between the two rigid connecting blocks (3) in the ring-shaped frame; the bending directions of the fixed half-bridge flexible modules (1) and the movable half-bridge flexible modules (2) are the same; The fixed half-bridge flexible modules (1) and the movable half-bridge flexible modules (2) are the same in structure and each comprise an intermediate block (5) and flexible branch chains (6); one or more flexible branch chains (6) are arranged on the two sides of the intermediate block (5) respectively, and the number of the flexible branch chains (6) on the two sides of the intermediate block (5) is the same or different; Wherein, The fixed half-bridge flexible modules (1) and the movable half-bridge flexible modules (2) are arranged in the same direction to generate differential motion; θ1 and θ2 are respectively the angles of the branch chains (6) of the fixed half-bridge flexible modules (1) and the branch chains (6) of the movable half-bridge flexible modules (2) to the same side of the horizontal line in the counterclockwise direction; θ1 and θ2 should be in the range of 0-90° at the same time or in the range of 90°-180° at the same time; For the bridge differential flexible displacement reduction mechanism, first, the drivers installed in the bridge mechanism are precharged, the drivers generate an input displacement Δx in the X direction, the input displacement is transmitted to the fixed half-bridge flexible modules and the movable half-bridge flexible modules through the rigid connecting blocks, the displacement is converted by the fixed half-bridge flexible modules and output in the Y direction, and the displacement is converted by the movable half-bridge flexible modules and output in the opposite direction of the Y direction, so that the two output displacements are superimposed to obtain a small output displacement, and the input displacement is reduced; For the fixed half-bridge flexible modules, when the driver inputs a horizontal displacement of 2Δx, the rigid blocks on the two sides not only generate a displacement Δx in the horizontal direction, but also generate a downward displacement Δy1 in the vertical direction, Δy1≈Δx / tan(θ1); For the movable half-bridge flexible modules, the transverse displacement Δx of the rigid blocks on the two sides causes a longitudinal displacement Δy2 of the output end of the mechanism relative to the rigid blocks on the two sides in the vertical direction, Δy2≈Δx / tan(θ2); The intermediate block of the movable half-bridge flexible modules outputs the reduced displacement outward; The output end of the whole mechanism is the intermediate block of the movable half-bridge flexible modules, and the output displacement of the intermediate block relative to the base is Δy = Δy2-Δy1, that is, the displacements of the upper and lower half-bridge flexible modules are used to offset each other to realize large-scale reduction of the input displacement of the driver; by changing the design parameters of the two half-bridge flexible modules, a displacement reduction of any scale can be obtained; in an extreme case, when the design parameters of the two bridge flexible modules are completely the same, the output displacement of the whole mechanism is 0, which means infinite reduction ratio; Wherein, The two ends of the driver (4) are fixedly connected with the two rigid connecting blocks, the driver (4) provides linear input to make the two rigid connecting blocks move away or approach; the driver (4) is a piezoelectric stack driver; ​ In order to make the structure more compact and simple, and also to reduce the weight of the structure, one concentrated flexibility type flexible branch is connected to each end of the middle block in the two half-bridge flexible modules. In the working process, the piezoelectric stack driver generates X direction displacement by changing the voltage on the piezoelectric stack driver. When the voltage increases, the piezoelectric stack driver generates X direction elongation movement. When the voltage decreases, the piezoelectric stack driver generates X direction contraction movement. The X direction displacement drives the two rigid connection blocks connected with the piezoelectric stack driver to generate X direction displacement. The X direction displacement drives the slot flexible hinge in the fixed half-bridge flexible amplification module and the movable half-bridge flexible amplification module connected with the rigid connection block to generate deformation, so that the two half-bridge flexible modules generate opposite Y direction displacement. After the two opposite Y direction displacements are superimposed and offset, a small Y direction displacement is output on the middle block of the movable half-bridge flexible module. Wherein, The bridge type differential flexible displacement reduction mechanism realizes the differential superposition of displacement by the combination of the two half-bridge flexible modules, so as to obtain a large displacement reduction ratio, thereby greatly improving the resolution and accuracy of the movement. The bridge type differential flexible displacement reduction mechanism realizes large range and ultra-high precision movement positioning by cooperating with the macro-motion platform.

2. A bridge differential compliant displacement reduction mechanism according to claim 1, wherein, The middle block of the fixed half-bridge flexible module (1) is connected with the rack, and the middle block of the movable half-bridge flexible module (2) is the output end of the whole mechanism.

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