Device for measuring rotating speed
By combining a reflector and a detector, the rotational speed of the shaft is calculated using light reflection, solving the problem of high-cost rotational speed measurement equipment and achieving low-cost, accurate rotational speed detection.
Patent Information
- Application Number
- CN202423217526.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-25
- Publication Date
- 2025-12-09
- Estimated Expiration
- 2034-12-25
AI Technical Summary
Existing speed measurement equipment is expensive and suffers from frictional resistance and slippage that cause speed deviations. There is a lack of simple and inexpensive detection methods.
By using a reflector in conjunction with two detectors, the rotational speed of the shaft is calculated by detecting the number of light rays reflected by the laser emitter and the reflector, thus avoiding the use of expensive components.
It achieves simple and low-cost speed detection, solves the problem of high-cost speed measurement equipment, and improves detection accuracy.
Smart Images
Figure CN223650560U_ABST
Abstract
Description
Technical Field
[0001] This application belongs to the field of measuring equipment manufacturing technology, specifically a device for measuring rotational speed. Background Technology
[0002] The rotational speed of a shaft is typically set via a drive mechanism. However, in practical applications, factors such as frictional resistance or slippage can cause deviations between the shaft's rotational speed and the set value. Many machines require feedback adjustment, which involves measuring the actual rotational speed of the shaft and then adjusting the set value based on this actual speed to achieve the desired speed for the application. However, methods for measuring the actual rotational speed typically include Hall effect speed measurement and photoelectric encoder speed measurement, which require expensive components and result in high costs. Utility Model Content
[0003] The purpose of this application is to address the shortcomings of existing technologies by designing a device for measuring rotational speed using a reflector and two detectors. This device can simply detect the rotational speed of a shaft without any expensive components, thus solving the problem of the lack of simple and inexpensive rotational speed measurement equipment.
[0004] To achieve the above objectives, this application provides the following technical solution:
[0005] A device for measuring rotational speed includes a laser emitter, a reflector, a first detector, and a second detector. The relative positions of the reflector, laser emitter, first detector, and second detector are fixed. The reflector is rotatable about the light emitted by the laser emitter as its central axis. The reflector is in a first state where the light emitted by the laser emitter can enter the first detector after passing through the reflector. When the reflector rotates 180° from the first state about the light emitted by the laser emitter as its central axis, in a second state, the light emitted by the laser emitter can enter the second detector after passing through the reflector. A connector with its axis coinciding with the light emitted by the laser emitter is provided on the side of the reflector facing away from the laser emitter.
[0006] Preferably, it also includes a frame, on which the laser emitter, the first detector, and the second detector are all mounted, and the reflector is rotatably mounted on the frame.
[0007] Preferably, the cross-section of the reflector is a right-angled isosceles triangle, the sidewall of the reflector corresponding to the hypotenuse of the right-angled isosceles triangle is a reflecting surface, the light emitted by the laser emitter is parallel to the plane containing the right-angled isosceles triangle, and the angle between the reflecting surface and the light emitted by the laser emitter is 45°.
[0008] Preferably, the light emitted by the laser emitter is perpendicular to the light reflected by the reflective surface into the first detector.
[0009] Preferably, the first detector and the second detector are located on the same side of the light emitted by the laser emitter. A corner prism is provided on the side of the laser emitter that faces away from the first detector. The corner prism has a first reflective plane and a second reflective plane. When the reflector rotates 180° about the light emitted by the laser emitter as the central axis, the light reflected by the reflective surface is reflected by the first reflective plane and then enters the second reflective plane and is reflected again into the second detector.
[0010] Preferably, both the first and second reflecting planes are perpendicular to the plane formed by the light emitted directly from the laser emitter and the light emitted from the laser emitter received by the first detector. The angle between the first and second reflecting planes is 90°, the angle between the light emitted from the laser emitter and the first reflecting plane is 45°, the angle between the light emitted from the laser emitter and the second reflecting plane is 45°, the distance between the reflector and the laser emitter is less than the distance between the side of the first reflecting plane facing away from the laser emitter and the laser emitter, and the distance between the reflector and the laser emitter is greater than the distance between the side of the first reflecting plane facing the laser emitter and the laser emitter. The distance of the side of the second reflecting plane facing the laser emitter is less than the length of the projection of the connecting line segment between the second detector and the laser emitter onto the light emitted from the laser emitter, and the distance of the side of the second reflecting plane facing away from the laser emitter is greater than the length of the projection of the connecting line segment between the second detector and the laser emitter onto the light emitted from the laser emitter.
[0011] Preferably, the connector is a threaded hole provided on the reflector.
[0012] Preferably, the connector includes a connecting seat, a first clamping block, a lead screw, a connecting post, and a second clamping block. The connecting seat is fixedly connected to one end of the connecting post, and the other end of the connecting post is fixedly connected to the side wall of the reflector facing away from the laser emitter. The central axis of the connecting post is collinear with the light emitted by the laser emitter. The two ends of the connecting post are rotatably connected to the frame. The lead screw is rotatably mounted on the side of the connecting seat facing away from the connecting post. The left section of the lead screw has a first thread, and the right section has a second thread. The first thread and the second thread are opposite. A first clamping block corresponding to the first thread and a second clamping block corresponding to the second thread are slidably mounted on the connecting seat. The junction of the first thread and the second thread is located on the central axis of the connecting post. The side wall of the first clamping block facing the second clamping block has a recessed first arc-shaped surface, and the side wall of the second clamping block facing the first clamping block has a recessed second arc-shaped surface. The projections of the first arc-shaped surface and the second arc-shaped surface on the side wall of the connecting seat facing away from the connecting post are arc-shaped line segments.
[0013] Compared with the prior art, the beneficial effects of this application are:
[0014] This application presents a device for measuring rotational speed by using a reflector in conjunction with two detectors. This device can easily detect the rotational speed of a shaft and does not contain any expensive components, thus solving the problem of the current lack of simple and inexpensive rotational speed measurement equipment. Attached Figure Description
[0015] Figure 1 This is a schematic diagram of the structure of this application;
[0016] Figure 2 for Figure 1 A schematic diagram of the top structure;
[0017] Figure 3 for Figure 2 Enlarged view of point A in the middle;
[0018] Figure 4 This is a schematic diagram of the first detector receiving light in this application;
[0019] Figure 5 This is a schematic diagram of the principle of the second detector receiving light in this application.
[0020] The components are as follows: 1. Laser emitter; 2. Reflector; 3. First detector; 4. Second detector; 5. Frame; 6. Reflecting surface; 7. Cornerstone prism; 8. First reflecting plane; 9. Second reflecting plane; 10. Connecting seat; 11. First clamping block; 12. Lead screw; 13. Connecting column; 14. First thread; 15. Second thread; 16. First arc-shaped surface; 17. Second arc-shaped surface; 18. Second clamping block; 19. Turntable; 20. Locking bolt; 21. Rotating shaft. Detailed Implementation
[0021] join Figure 1-5 A device for measuring rotational speed includes a laser emitter 1, a reflector 2, a first detector 3, and a second detector 4. The relative positions of the reflector 2, laser emitter 1, first detector 3, and second detector 4 are fixed. The reflector 2 is rotatable about the light emitted by the laser emitter 1 as a central axis. The reflector 2 is positioned such that the light emitted by the laser emitter 1 can enter the first detector 3 after passing through the reflector 2 (e.g.,...). Figure 4 The state shown); when the reflector 2 rotates 180° from the first state around the light emitted by the laser emitter 1 to the second state (as shown in the figure); Figure 5 As shown in the diagram, the light emitted by the laser emitter 1 can enter the second detector 4 after passing through the reflector 2. The reflector 2 has a connector on the side facing away from the laser emitter 1, whose axis coincides with the light emitted by the laser emitter 1.
[0022] In this embodiment, during use, the first detector 3 and the second detector 4 are connected to the input terminal of the PLC system, and then the free end of the rotating shaft 21 (such as a drive shaft, the output shaft of a reducer, etc.) is fixedly connected via a connector. During rotation, the rotating shaft 21 drives the reflector 2 to rotate. The rotational speed of the rotating shaft 21 is determined by the number of times the first detector 3 detects the light emitted by the laser emitter 1 and the number of times the second detector 4 detects the light emitted by the laser emitter 1. For example, initially, the first detector 3 detects the light emitted by the laser emitter 1. Then, the rotating shaft 21 rotates. When the second detector 4 detects the light emitted by the laser emitter 1, the rotating shaft 21 has rotated half a turn, that is, rotated 180°. If the first detector 3 detects two light emitted by the laser emitter 1, and the second detector 4 detects one light emitted by the laser emitter 1, then the rotating shaft 21 has rotated one full turn. Thus, the PLC system calculates the number of times the first detector 3 and the second detector 4 detect the light emitted by the laser emitter 1 to determine the number of rotations of the rotating shaft 21. The first detector 3 and the second detector 4 can also be optical sensors.
[0023] As a preferred embodiment, the system also includes a frame 5, on which the laser emitter 1, the first detector 3, and the second detector 4 are all mounted, and the reflector 2 is rotatably mounted on the frame 5. By mounting the laser emitter 1, the first detector 3, and the second detector 4 on the frame 5, these components are integrated into a single unit, facilitating storage and transport. Because the reflector 2 rotates with the pivot 21, it is rotatably mounted on the frame 5.
[0024] As a preferred embodiment, the cross-section of the reflector 2 is a right-angled isosceles triangle. The sidewall of the reflector 2 corresponding to the hypotenuse of the right-angled isosceles triangle is the reflecting surface 6. The light emitted by the laser emitter 1 is parallel to the plane containing the right-angled isosceles triangle. The angle between the reflecting surface 6 and the light emitted by the laser emitter 1 is 45°. With this configuration, the angle between the light emitted by the laser emitter 1 and the reflecting surface 6 is 45°, and the angle between the light emitted by the laser emitter 1 and the reflecting surface 6, received by the first detector 4, is also 45°, based on the principle that the angle of incidence equals the angle of reflection. This arrangement makes the components on the frame 5 more aesthetically pleasing.
[0025] As a preferred embodiment, the light emitted by the laser emitter 1 is perpendicular to the light reflected by the reflective surface 6 into the first detector 3. This arrangement places the first detector 3 on one side of the light emitted by the laser emitter 1, resulting in an aesthetically pleasing arrangement of the components on the frame 5.
[0026] As a preferred embodiment, the first detector 3 and the second detector 4 are located on the same side of the light emitted by the laser emitter 1, which saves the volume of the frame 5 and improves the space utilization of the frame 5. A corner prism 7 is provided on the side of the laser emitter 1 that is away from the first detector 3. The corner prism 7 has a first reflecting plane 8 and a second reflecting plane 9. When the reflector 2 rotates 180° about the light emitted by the laser emitter 1 as the central axis, the light reflected by the reflector 6 is reflected by the first reflecting plane 8 and then enters the second reflecting plane 9 and is reflected again into the second detector 4.
[0027] In a preferred embodiment, both the first reflecting plane 8 and the second reflecting plane 9 are perpendicular to the plane formed by the light emitted directly from the laser emitter 1 and the light emitted from the laser emitter 1 received by the first detector 3. The angle between the first reflecting plane 8 and the second reflecting plane 9 is 90°. That is, assuming the light emitted directly from the laser emitter 1 is M, and the light emitted from the laser emitter received by the first detector 3 is L, where L is the light reflected from M by the reflecting surface 6, then L and M coexist in the same plane, and this plane is perpendicular to both the first reflecting plane 8 and the second reflecting plane 9. The angle between the light emitted from the laser emitter 1 and the first reflecting plane 8 is 45°, and the angle between the light emitted from the laser emitter 1 and the second reflecting plane 9 is also 45°. Figure 5 As shown, with this configuration, the light emitted by the laser emitter 1, after passing through the reflecting surface 6 and reflecting onto the first reflecting plane 8, can enter the second reflecting plane 9, and then be reflected again by the second reflecting plane 9 before entering the detector 4. The distance between the reflector 2 and the laser emitter 1 is less than the distance between the side of the first reflecting plane 8 facing away from the laser emitter 1 and the laser emitter 1, and the distance between the reflector 2 and the laser emitter 1 is greater than the distance between the side of the first reflecting plane 8 facing the laser emitter 1 and the laser emitter 1. The purpose of this configuration is to ensure that the reflector 2... When the reflecting surface 6 faces the first reflecting plane 8, the light reflected from the reflector 2 can completely enter the first reflecting plane 8; the distance of the second reflecting plane 9 facing the laser emitter 1 is less than the length of the projection of the connecting line segment between the second detector 4 and the laser emitter 1 onto the light emitted by the laser emitter 1, and the distance of the second reflecting plane 9 facing away from the laser emitter 1 is greater than the length of the projection of the connecting line segment between the second detector 4 and the laser emitter 1 onto the light emitted by the laser emitter 1. The purpose of this setting is to avoid the second detector 4 receiving light outside the second reflecting plane 9, which would lead to misjudgment.
[0028] As a preferred embodiment, the connector is a threaded hole provided on the reflector 2. This allows for a fixed connection with the rotating shaft 21 via the threaded hole, enabling the reflector 2 to rotate with the rotating shaft 21.
[0029] In a preferred embodiment, the connector includes a connecting seat 10, a first clamping block 11, a lead screw 12, a connecting post 13, and a second clamping block 18. The connecting seat 10 is fixedly connected to one end of the connecting post 13, and the other end of the connecting post 13 is fixedly connected to the side wall of the reflector 2 facing away from the laser emitter 1. The central axis of the connecting post 13 is collinear with the light emitted by the laser emitter 1. The two ends of the connecting post 13 are rotatably connected to the frame 5. The lead screw 12 is rotatably mounted on the side of the connecting seat 10 facing away from the connecting post 13. The left section of the lead screw 12 has a first thread 14, and the right section has a second thread 18. 5. The first thread 14 is opposite to the second thread 15. A first clamping block 11 corresponding to the first thread 14 and a second clamping block 18 corresponding to the second thread are slidably disposed on the connecting seat 10. The junction of the first thread and the second thread is located on the central axis of the connecting post 13. The first clamping block 11 has a recessed first arc-shaped surface 16 on its side wall facing the second clamping block 18. The second clamping block 18 has a recessed second arc-shaped surface 17 on its side wall facing the first clamping block 11. The projections of the first arc-shaped surface 16 and the second arc-shaped surface 17 on the side wall of the connecting seat 10 facing away from the connecting post 13 are arc-shaped line segments.
[0030] With this configuration, rotating the lead screw 12 causes the first clamping block 11 and the second clamping block 18 to clamp the rotating shaft 21. Since the first thread 14 and the second thread 15 on the lead screw 12 are opposite threads, and other parameters such as the pitch are the same, the first clamping block 11 and the second clamping block 18 will move synchronously when the lead screw 12 is rotated. During the movement, they either move away from each other or move closer together. This ensures that the midpoint between the first clamping block 11 and the second clamping block 18 is always on the light line emitted by the laser reflector 1, thus ensuring that after clamping the rotating shaft 21, the central axis of the rotating shaft 21 is collinear with the light emitted by the laser reflector 1. The first arc-shaped surface 16 and the second arc-shaped surface 17 are designed to ensure better contact between the first clamping block 11 and the second clamping block 18 and the rotating shaft 21, preventing slippage.
[0031] Preferred, such as Figure 3 As shown, a turntable 19 is coaxially provided at one end of the lead screw 12. The turntable 19 has an axially upward screw hole at a distance away from the lead screw 12. The two ends of the locking bolt 20 are engaged with the screw hole. After this arrangement, after the first clamping block 11 and the second clamping block 18 are clamped by the lead screw 12, the lead screw 12 is locked by screwing the locking bolt 20 into the screw hole and abutting one end of the screw against the side wall of the connecting seat 10, thus preventing the lead screw 12 from rotating.
Claims
1. A device for measuring rotational speed, characterized in that, The system includes a laser emitter (1), a reflector (2), a first detector (3), and a second detector (4). The relative positions of the reflector (2), laser emitter (1), first detector (3), and second detector (4) are fixed. The reflector (2) can rotate about the light emitted by the laser emitter (1) as the central axis. The reflector (2) can be in a first state where the light emitted by the laser emitter (1) can enter the first detector (3) after passing through the reflector (2). When the reflector (2) rotates 180° from the first state about the light emitted by the laser emitter (1) as the central axis in the second state, the light emitted by the laser emitter (1) can enter the second detector (4) after passing through the reflector (2). The reflector (2) has a connector on the side facing away from the laser emitter (1) whose axis coincides with the light emitted by the laser emitter (1).
2. The device for measuring rotational speed according to claim 1, characterized in that, It also includes a frame (5), on which the laser emitter (1), the first detector (3), and the second detector (4) are all mounted, and the reflector (2) is rotatably mounted on the frame (5).
3. The device for measuring rotational speed according to claim 2, characterized in that, The cross-section of the reflector (2) is a right-angled isosceles triangle. The side wall of the reflector (2) corresponding to the hypotenuse of the right-angled isosceles triangle is the reflecting surface (6). The light emitted by the laser emitter (1) is parallel to the plane containing the right-angled isosceles triangle. The angle between the reflecting surface (6) and the light emitted by the laser emitter (1) is 45°.
4. The device for measuring rotational speed according to claim 3, characterized in that, The light emitted by the laser emitter (1) is perpendicular to the light reflected by the reflective surface (6) into the first detector (3).
5. The device for measuring rotational speed according to claim 3, characterized in that, The first detector (3) and the second detector (4) are located on the same side of the light emitted by the laser emitter (1). A corner prism (7) is provided on the side of the light emitted by the laser emitter (1) away from the first detector (3) on the frame (5). The corner prism (7) has a first reflecting plane (8) and a second reflecting plane (9). When the reflector (2) rotates 180° around the light emitted by the laser emitter (1) as the central axis, the light reflected by the reflecting surface (6) is reflected by the first reflecting plane (8) and then enters the second reflecting plane (9) and is reflected again into the second detector (4).
6. The device for measuring rotational speed according to claim 5, characterized in that, The first reflecting plane (8) and the second reflecting plane (9) are both perpendicular to the plane formed by the light emitted directly from the laser emitter (1) and the light emitted from the laser emitter (1) received by the first detector (3). The angle between the first reflecting plane (8) and the second reflecting plane (9) is 90°. The angle between the light emitted from the laser emitter (1) and the first reflecting plane (8) is 45°. The angle between the light emitted from the laser emitter (1) and the second reflecting plane (9) is 45°. The distance between the reflector (2) and the laser emitter (1) is less than the distance from the side of the first reflecting plane (8) facing away from the laser emitter (1) to the laser emitter. The distance between (1) and the laser emitter (1) is greater than the distance between the side of the first reflective plane (8) facing the laser emitter (1) and the laser emitter (1), the distance of the side of the second reflective plane (9) facing the laser emitter (1) is less than the length of the projection of the connecting line segment between the second detector (4) and the laser emitter (1) on the light emitted by the laser emitter (1), and the distance of the side of the second reflective plane (9) away from the laser emitter (1) is greater than the length of the projection of the connecting line segment between the second detector (4) and the laser emitter (1) on the light emitted by the laser emitter (1).
7. The device for measuring rotational speed according to claim 1, characterized in that, The connector is a threaded hole provided on the reflector (2).
8. The device for measuring rotational speed according to claim 2, characterized in that, The connector includes a connecting seat (10), a first clamping block (11), a lead screw (12), a connecting post (13), and a second clamping block (18). The connecting seat (10) is fixedly connected to one end of the connecting post (13), and the other end of the connecting post (13) is fixedly connected to the side wall of the reflector (2) facing away from the laser emitter (1). The central axis of the connecting post (13) is collinear with the light emitted by the laser emitter (1). The two ends of the connecting post (13) are rotatably connected to the frame (5). The lead screw (12) is rotatably mounted on the side of the connecting seat (10) facing away from the connecting post (13). The left section of the lead screw (12) is provided with a first thread (14), and the right section is provided with a second thread (15). The first thread (14) is opposite to the second thread (15). A first clamping block (11) corresponding to the first thread (14) and a second clamping block (18) corresponding to the second thread are slidably arranged on the connecting seat (10). The junction of the first thread and the second thread is located on the central axis of the connecting column (13). The first clamping block (11) has a recessed first arc-shaped surface (16) on its side wall facing the second clamping block (18). The second clamping block (18) has a recessed second arc-shaped surface (17) on its side wall facing the first clamping block (11). The projection of the first arc-shaped surface (16) and the second arc-shaped surface (17) on the side wall of the connecting seat (10) facing away from the connecting column (13) is an arc-shaped line segment.