Prism switching device

Abstract

The invention relates to a prism switching device. The prism switching device comprises a prism wheel, a central shaft, a transmission system and a mechanical positioning and locking device, the prism wheel is disc-shaped and rotates around a central shaft, and a plurality of holes for mounting prisms are uniformly distributed in the disc part of the prism wheel; the top end of the central shaft is connected with the mechanical positioning and locking device; the transmission system comprises a motor, a small gear and a large gear, a motor shaft of the motor is connected with the small gear, a notch is formed in the outer side of the small gear, the small gear is meshed with the large gear, and the large gear is installed at the bottom of the prism wheel and directly connected with the prism wheel; the mechanical positioning and locking device comprises a swing arm, a spring and a clamping edge, the swing arm is arranged outside the prism wheel, the clamping edge is arranged at the top of the swing arm, and the spring is connected with the other end of the swing arm. Through the device, the prism switching process is more stable, the repeated positioning of the prism is accurate, and the reliability of the system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of mechanical engineering, and in particular to a prism switching device. Background Art

[0002] Prism switching devices play an important role in astronomical optical instruments, imaging equipment, and astronomical observation. In order to perform precise spectral separation and analysis in different spectral ranges, accurate switching and positioning of prisms are essential. However, existing prism switching devices often face many challenges in high-precision application scenarios.

[0003] The traditional prism switching method usually adopts coaxial drive, that is, the motor is directly installed on the prism wheel, the prism is switched by driving the motor, and the code disk (encoder) is installed on the rotating shaft of the motor to detect the rotation angle, thereby providing positioning feedback. This method can achieve angle and position control through closed-loop control, which is very common in systems that require high-precision motion control. However, although this design can provide high-precision control effects in some applications, it also has obvious limitations. First, the feedback code disk is large in size, especially in miniaturized designs, the volume and weight of the code disk may occupy valuable space inside the system, limiting the compactness of the system. In addition, the cost of high-precision code disks is high, which increases the manufacturing cost of the entire system. Secondly, there may be a problem of overperformance in the traditional coaxial drive method. For most applications, only a positioning accuracy of more than ten to thirty arc seconds is required to meet the requirements, but the design of high-precision code disks often exceeds this requirement, resulting in increased system complexity and unnecessary increase in cost and maintenance difficulty. In addition to the coaxial drive method, another common prism switching method is to achieve it only by direct meshing of large gears and small gears. The motor is installed on one side of the eccentric axis, and drives the large gear to rotate by driving the small gear to achieve the switching of the prism wheel. However, this design has a significant problem, namely the tooth side clearance. This clearance causes errors in the transmission system, making the positioning of the prism wheel inaccurate after switching. Even if the motor control accuracy is very high, the gap between the gears will still introduce errors, resulting in unstable switching positions of the prism, which cannot meet the requirements of high-precision applications. In addition, in traditional gear transmission systems, tooth clearance and processing errors inevitably exist, resulting in insufficient positioning accuracy of the prism after switching. After multiple switching, the system's repeatability is also difficult to guarantee, and the prism may not be able to return to its original precise position, which is a significant defect for systems that require long-term stable operation. Coupled with the friction and wear problems between the gears, the reliability and life of the system are also affected. Therefore, a prism switching device that can ensure high precision while having high reliability and stability is required. Summary of the invention

[0004] In order to solve the existing technical problems, the present invention provides a prism high-precision switching device for spectrum separation.

[0005] The specific contents of the present invention are as follows: a prism switching device, including a prism wheel, a central axis, a transmission system, and a mechanical positioning and locking device; the prism wheel is in the shape of a disk, the prism wheel rotates around the central axis, and a plurality of holes for installing prisms are evenly distributed on the disk part of the prism wheel; the top of the central axis is connected to the mechanical positioning and locking device; the transmission system includes a motor, a pinion and a gear, the motor shaft of the motor is connected to the pinion, the outer side of the pinion is provided with a notch, the pinion is meshed with the gear, the gear is installed at the bottom of the prism wheel and is directly connected to the prism wheel; the mechanical positioning and locking device includes a swing arm, a spring and a locking edge, the swing arm is arranged on the outside of the prism wheel, the top is provided with a locking edge, the spring is connected to the other end of the swing arm, when the prism wheel rotates, the locking edge is separated from the prism wheel under the movement of the swing arm, and when the prism wheel rotates to the next prism position, the swing arm moves under the action of the spring, and the locking edge locks the prism wheel.

[0006] Furthermore, the small gear switches to the notch when it rotates one circle. The notch is crescent-shaped and has a symmetrical arc design. The curvature radius of the curved surface at the notch is larger than the curvature radius of the tooth top circle of the large gear. When the notch of the small gear is aligned with the large gear, the small gear disengages from the large gear at the notch, and the large gear enters a free state, that is, the large gear can rely on inertia and the action of the spring and the swing arm to perform slight free rotation.

[0007] Furthermore, the transmission ratio of the transmission system satisfies that when the small gear rotates one circle, the large gear drives the prism wheel to complete the switching of one prism.

[0008] Furthermore, a plurality of groups of small bearings located outside the prism are provided on the edge of the prism wheel, each group including two small bearings. The space formed by the two small bearings and the edge of the prism wheel can position and lock the locking edge, and the locking edge can be separated from the space when the prism wheel rotates.

[0009] Furthermore, the edge of the swing arm is extended from the contact point between the locking edge and the small bearing, and the surface of the locking edge is a plane or a curved surface.

[0010] Furthermore, the positioning edge includes two surfaces, and the angle between the two surfaces is between 40 and 50 degrees. When the prism wheel needs to rotate in both directions, the two surfaces of the positioning edge are designed to be a symmetrical inclined structure; when only unidirectional rotation is required, an asymmetric structure with one side being a plane and the other side being an inclined surface is adopted.

[0011] The notched pinion of the present invention enables the transmission system to have an intermittent disengagement mechanism, and the design of the mechanical positioning and locking device enables the device to be accurately locked when the prism wheel rotates, ensuring the high precision of the system in spectral separation applications and having good application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The specific implementation of the present invention will be further explained below in conjunction with the accompanying drawings.

[0013] Figure 1 It is the front view of the prism switching device of the present invention.

[0014] Figure 2 It is a top view of the prism switching device of the present invention. DETAILED DESCRIPTION

[0015] Combination Figure 1 and Figure 2 The prism high-precision switching device for spectrum separation of the present invention mainly includes three parts: a prism wheel and a central axis, a transmission system, and a mechanical positioning and locking device.

[0016] In this embodiment, the prism wheel 1 is in the shape of a disk as a whole, wherein the central part is a cylindrical structure, a fixed central axis 5 is set in the cylinder, and the top of the central axis 5 is connected to a mechanical positioning and locking device. The prism wheel 1 rotates around the central axis 5, and the disk part of the prism wheel 1 is evenly distributed with a plurality of holes for installing the prism 2, ensuring that the prism 2 can be accurately aligned with the optical path when the prism wheel 1 rotates, meeting the spectral separation requirements. In this embodiment, four prisms are provided, evenly distributed on the edge of the prism wheel 1.

[0017] The transmission system includes a motor 4, a small gear 9 and a large gear 10. The motor 4 is the core driving part of the transmission system and is responsible for providing power to drive the prism wheel 1 to rotate. The present invention can select a DC motor or a stepper motor according to the application requirements of the system.

[0018] The motor 4 is directly connected to the pinion 9 through its motor shaft 3 to ensure power transmission. The pinion 9 is driven to rotate by the motor 4, and its external gear part is meshed with the large gear 10. In the design of the pinion 9, special consideration is given to the existence of a notch. The notch design allows the pinion 9 to temporarily disengage from the large gear 10 when it rotates to a specific angle. The pinion 9 can switch to the notch state every time it rotates one circle. It ensures that it can reduce excessive impact on the large gear 10 during the transmission process during the disengagement process, and allows the system to automatically make short adjustments and buffers when the prism is switched to ensure smooth switching.

[0019] The notch of the pinion 9 is crescent-shaped and symmetrically arc-shaped, and its radius of curvature is greater than the radius of curvature of the tooth top circle of the large gear 10. When the notch of the pinion 9 is aligned with the large gear 10, the large gear 10 disengages from the meshing with the pinion 9 and enters a state of free rotation, that is, the large gear 10 can rely on inertia and the action of the spring and the swing arm to perform slight free rotation.

[0020] The large gear 10 is installed at the bottom of the prism wheel 1, directly connected to the prism wheel 1, and is responsible for driving the prism wheel 1 to rotate. The large gear 10 transmits the power of the motor 4 to the prism wheel 1 through meshing with the small gear 9, thereby realizing the switching of the prism.

[0021] When the notch of the pinion 9 is aligned with the large gear 10, the large gear 10 enters a free state. At this time, the large gear 10 relies on inertia and the spring 8 swing arm 7 in the system to rotate slightly freely. This free rotation allows the large gear 10 to be fine-tuned when the prism is switched, ensuring that the prism wheel 1 can smoothly switch to the position of the next prism. Finally, the large gear 10 will be firmly locked under the action of the locking edges 11 and 12 to ensure the precise positioning after the prism is switched.

[0022] The design of the transmission ratio of the transmission system needs to take into account the rotation angle requirements of the prism wheel 1, as well as the number, size, shape, etc. of the prisms, and is adjusted according to specific application requirements to ensure that the prisms can meet the requirements of spectral separation after switching. p The number of teeth Z of the large gear 10 and the small gear 9 in the transmission system l , Z s The following design relationship exists: N is evenly distributed on the prism wheel 1 p prisms, each time the prism is switched, the angle of rotation of prism wheel 1 is: θ=360° / N p To ensure the accurate switching of the prism in the optical path, the large gear 10 rotates by an angle of θ each time. The small gear 9 drives the large gear 10 through the motor 4, and the transmission ratio between the two is defined as: R=Z l / Z s Each time the small gear 9 rotates a full circle (360°), the large gear 10 rotates by an angle of: θ l =360° / R=(360°•Z s ) / Z l In order to achieve the requirement that the prism wheel 1 completes a prism switch every time the small gear 9 rotates a full circle, the rotation angle of the large gear 10 must satisfy: θ l =360° / N p . From this we can get: (360°•Z s ) / Z l =360° / N pAfter sorting, the relationship between the number of teeth is: Z l =N p •Z s Among them, the number of teeth of pinion 9 is Z s It is the actual number of teeth, not the equivalent number of teeth which takes the gap into account.

[0023] The calculated transmission ratio ensures that the rotation relationship between the pinion 9 and the large gear 10 can accurately control the switching position of the prism. Through the reasonable transmission ratio design, the large gear 10 can accurately drive the prism wheel 1 to complete the switching of a prism every time the pinion 9 rotates one circle, so that the system can maintain consistent high precision under different working conditions.

[0024] The mechanical positioning and locking device includes a swing arm 7, a spring 8 and a locking edge. Two small bearings are provided outside the edge of the prism wheel 1 and at positions corresponding to the back of each filter. Two small bearings form a group, and a total of four groups of small bearings are provided. The space formed by the two small bearings 6 and the edge of the prism wheel 1 allows the locking edge to be positioned and locked, and the locking edge can be separated from the space when the prism wheel 1 rotates. The small bearing 6 cooperates with the swing arm 7 and the locking edge to ensure the switching accuracy of the prism and the spectrum separation effect.

[0025] The spring 8 plays a vital role in the mechanical positioning and locking device. It applies elastic force to the swing arm 7 to ensure that the swing arm 7 can always be in close contact with the small bearing 6 outside the prism wheel 1. In the actual design, one end of the spring 8 is connected to the swing arm, and the other end is fixed to the base of the device.

[0026] The swing arm 7 is in close contact with the small bearing 6 outside the prism wheel 1 through the spring force, which plays a role in positioning and supporting. The design of the swing arm 7 has been finely adjusted to ensure that it can provide stable support for the prism wheel 1 when appropriate force is applied, and at the same time ensure that the swing arm 7 can flexibly respond to the needs of the system during the prism switching process. The cooperation between the swing arm 7 and the spring 8 enables the entire system to adjust quickly when the prism is switched, and accurately position the prism to the specified position after the switch is completed.

[0027] The locking edge is a key part to achieve the final locking of the prism. In this embodiment, two locking edges 11 and 12 are set at one end of the swing arm 7. The surface design of the locking edges 11 and 12 can be a flat surface or a curved surface to meet different system requirements. The angle between the two surfaces is usually set to between 40 and 50 degrees. In fact, the sharper the angle, the better it is while ensuring that the system does not self-lock.

[0028] The design of the locking edges 11 and 12 is flexible and diverse: if the prism wheel 1 needs to rotate in both directions, the two inclined surfaces can be designed as a symmetrical structure; if only one-way rotation is required, an asymmetrical design with one side being a flat surface and the other side being an inclined surface can be adopted. This design can not only ensure the stability of the prism during the switching process, but also prevent the misoperation of reverse rotation, further improving the reliability of the system.

[0029] In this embodiment, the locking edges are two symmetrical inclined planes with an included angle of 45°. The ends of the two locking edges are parallel to the edge of the swing arm, so that the cross-section there is an isosceles trapezoid, which can realize clockwise or counterclockwise switching of the prism to meet various usage requirements.

[0030] The working process of the mechanical positioning and locking device is as follows: when the prism wheel 1 completes the switching of the prism 2 under the action of the transmission system, the mechanical positioning and locking device will achieve the final locking of the prism 2 through the cooperation of the locking edges 11 and 12 and the small bearing 6. Regardless of whether there is a small mechanical gap in the system, the locking edges 11 and 12 can automatically adjust and fit tightly to the prism wheel 1 under the action of the spring force and the swing arm 7 to ensure the accuracy of the position of the prism 2. Through this locking mechanism, the system can ensure that the prism 2 is stable in the predetermined position after each prism 2 is switched, avoiding any possible movement, and ensuring the high accuracy of the system in spectral separation applications.

[0031] The specific operations of this embodiment are as follows: Take switching the prism clockwise as an example: In this embodiment, four prisms (i.e., N p =4), the number of teeth of the pinion 9 is selected as 10 teeth (i.e. Z s =10) According to Z l =N p •Z s Relationship, the number of teeth Z of the large gear 10 l 40. Under this design: every time the small gear 9 rotates a full circle, the large gear 10 rotates 90° to complete a prism switch.

[0032] Before the prism wheel 1 starts to rotate, the prism is located in the optical path, and the swing arm 7 uses the elastic force of the spring 8 to press the locking edges 11 and 12 tightly into the two small bearings 6 outside the prism wheel 1, ensuring that the prism wheel 1 remains stable at the current prism position. At this time, the two surfaces of the locking edges 11 and 12 are in close contact with the surface of the small bearing 6, and the prism wheel 1 is firmly locked.

[0033] When the operation starts, the motor 4 is started by the control system. After the motor 4 receives the rotation instruction, the motor shaft 3 starts to rotate counterclockwise, and drives the pinion 9 directly connected thereto to rotate counterclockwise through the motor shaft 3.

[0034] As the pinion 9 rotates, the tooth surface of the pinion 9 meshes with the tooth surface of the large gear 10, and the power is transmitted to the large gear 10, and further transmitted to the prism wheel 1 mounted on the large gear 10. Due to the setting of the transmission ratio, every time the pinion 9 rotates one circle, the large gear 10 will drive the prism wheel 1 to rotate 90 degrees. When the pinion 9 rotates one circle, the motor 4 stops.

[0035] At the beginning of the rotation, the locking edges 11 and 12 gradually separate from the contact point of the small bearing 6, and the swing arm 7 moves slightly outward, allowing the prism wheel 1 to rotate smoothly. At this time, although the locking edges 11 and 12 are out of direct contact, they still maintain a close distance, ready to be re-locked when the prism wheel 1 reaches the next prism position. The prism wheel 1 begins to rotate clockwise, driving the upper prism out of the light path and moving the next prism into the light path. During the rotation of the prism wheel, since the pinion 9 is designed with a notch, when the pinion 9 rotates until the notch is aligned with the large gear 10, the pinion 9 and the large gear 10 are temporarily disengaged, and the prism wheel 1 enters a free state. In this state, the prism wheel 1 continues to rotate slightly by inertia. At this time, the prism wheel 1 rotates to the position of the next prism. Under the push of the spring force, the swing arm 7 quickly presses the locking edges 11 and 12 to the small bearing 6. The locking edges 11 and 12 gradually approach and finally contact the inner surface of the small bearing 6 again, so that the prism wheel 1 stops rotating and stabilizes at the new prism position. The surface design of the locking edges 11 and 12 ensures that even if there is a slight mechanical gap, slight adjustments can be made automatically to achieve accurate locking of the prism wheel 1 .

[0036] When the locking edges 11 and 12 completely lock the prism wheel 1, the swing arm 7 remains fixed under the action of the spring force. At this time, the rotation of the prism wheel 1 stops and the system enters a stable state. At this time, the operator can perform spectral separation or other optical operations as needed.

[0037] If multiple prisms need to be switched continuously, the operator can issue rotation instructions continuously through the control system, and the prism wheel 1 will rotate clockwise in sequence to complete the switching of each prism in order. After each switch is completed, the system will automatically lock the prism wheel 1 and continue the next operation after the lock is confirmed, ensuring the efficiency and accuracy of the entire process.

[0038] The prism switching device of the present application realizes precise switching and stable positioning of the prism through mechanical transmission and positioning devices, ensuring the accuracy of spectral separation and the efficiency of the system. Through the design of notched pinions and a latching edge with a certain tilt angle, the notched pinion enables the transmission system to have an intermittent disengagement mechanism, and the latching edge design can support bidirectional rotation or unidirectional locking according to needs, so that the device can adapt to different operating scenarios. The prism switching device of the present application can be used to switch various optical elements such as prisms, gratings, plane mirrors, lenses, filters, etc.

[0039] Many specific details are described in the above description to facilitate a full understanding of the present invention. However, the above description is only a preferred embodiment of the present invention. The present invention can be implemented in many other ways different from those described herein, so the present invention is not limited to the specific implementation disclosed above. At the same time, any person familiar with the art can make many possible changes and modifications to the technical solution of the present invention using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present invention, or modify it into an equivalent embodiment of equivalent changes. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still falls within the scope of protection of the technical solution of the present invention.

Claims

1. A prism switching device, characterized in that: The invention comprises a prism wheel, a central axis, a transmission system, and a mechanical positioning and locking device. The prism wheel is in a disc shape and can be installed with a plurality of prisms. The prism wheel rotates around the central axis, and a plurality of holes for installing the prisms are evenly distributed on the disc part of the prism wheel. The top of the central axis is connected with the mechanical positioning and locking device. The transmission system comprises a motor, a pinion and a gear. The motor shaft of the motor is connected with the pinion, and a notch is arranged on the outer side of the pinion. The pinion meshes with the gear. The gear is arranged at the bottom of the prism wheel and is directly connected with the prism wheel. The mechanical positioning and locking device comprises a swing arm, a spring and a locking edge. The swing arm is arranged outside the prism wheel, and a locking edge is arranged on the top. The spring is connected with the other end of the swing arm. When the prism wheel rotates, the locking edge is separated from the prism wheel under the movement of the swing arm. When the prism wheel rotates to the next prism position, the swing arm moves under the action of the spring, and the locking edge locks the prism wheel.

2. The prism switching device according to claim 1, characterized in that: The small gear switches to the notch when it rotates one circle. The notch is crescent-shaped and has a symmetrical arc design. The curvature radius of the curved surface at the notch is larger than the curvature radius of the tooth top circle of the large gear. When the notch of the small gear is aligned with the large gear, the small gear disengages from the large gear at the notch, and the large gear enters a free state, that is, the large gear can rotate slightly freely by relying on inertia, springs, and swing arms.

3. The prism switching device according to claim 2, characterized in that: The transmission ratio of the transmission system satisfies that the large gear drives the prism wheel to complete the switching of one prism every time the small gear rotates one circle.

4. The prism switching device according to claim 1, characterized in that: Several groups of small bearings outside the prism are arranged on the edge of the prism wheel, each group includes two small bearings, and the space formed by the two small bearings and the edge of the prism wheel can position and lock the locking edge, and the locking edge can be separated from the space when the prism wheel rotates.

5. The prism switching device according to claim 4, characterized in that: The edge of the swing arm is extended from the contact point between the locking edge and the small bearing, and the surface of the locking edge is a plane or a curved surface.

6. The prism switching device according to claim 5, characterized in that: The positioning edge includes two surfaces, and the angle between the two surfaces is between 40 and 50 degrees. When the prism wheel needs to rotate in both directions, the two surfaces of the positioning edge are designed to be a symmetrical inclined structure; when only unidirectional rotation is required, an asymmetric structure with one side being a plane and the other side being an inclined surface is adopted.

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