Rotational inertia testing device

Abstract

The utility model relates to a rotational inertia testing device comprising a pair of rotating shaft supports arranged on a platform, and the rotating shaft supports are used for fixing a rotating shaft of an object to be tested. The end part of the rotating shaft is provided with a disc wound with a string, and the other end of the string is vertically connected with a weight; a first sensor and a second sensor which are connected with a measuring device are arranged on the end side of the platform in the longitudinal direction and used for detecting a falling weight, and the measuring device triggers an instruction for starting timing according to feedback of the first sensor and triggers an instruction for stopping timing according to feedback of the second sensor. And calculating the rotational inertia of the to-be-measured object according to the calculated time and a rotational inertia formula of the rotor. Based on a weight falling method, potential energy of a heavy object is converted into rotation energy of a rotor and kinetic energy of the heavy object. The device is simple in structure, easy to operate, low in cost and good in detection effect, the detection principle is visual and easy to understand, the measurement process is easy to understand and explain, students and non-professionals are helped to understand related physical concepts, and the device has high practicability and wide applicability.

Description

Technical Field

[0001] The utility model specifically relates to a moment of inertia testing device, belonging to the technical field of detection and measurement. Background Art

[0002] In mechanical engineering, the moment of inertia is crucial for the design of rotating mechanical parts, such as the movement of motor rotors, gear transmissions, and some rotating objects that require high control accuracy. Reducing the moment of inertia can improve the response speed and accuracy of the system; accurately calculating the moment of inertia can optimize the dynamic performance of the system and reduce vibration and energy loss.

[0003] There are many methods for testing the moment of inertia, such as the drop weight method, simulation calculation method, etc.; among them, the accuracy of the model in the simulation calculation method has a greater impact on the results; the drop weight method has low cost, simple equipment and easy operation; therefore, the use of the drop weight method to test the moment of inertia has gradually been widely used.

[0004] The commonly used rotational inertia simulation calculation method may require higher computing resources and time for large and complex models. There are also certain theoretical assumptions that limit the calculation process, which deviate from the actual situation. The falling weight method is more applicable.

[0005] Therefore, the utility model provides a novel moment of inertia testing device based on the falling weight method. Summary of the invention

[0006] In order to solve the deficiencies of the prior art, the utility model aims to provide a moment of inertia testing device.

[0007] In order to achieve the above objectives, the utility model adopts the following technical solutions:

[0008] A moment of inertia testing device comprises a pair of rotating shaft brackets arranged on a platform, wherein the rotating shaft brackets are used to fix the rotating shaft of the object to be tested;

[0009] The end of the rotating shaft is provided with a disc around which a thin rope is wound, and the other end of the thin rope is vertically connected to a weight;

[0010] The end side of the platform is provided with a first sensor and a second sensor connected to a measuring device along the longitudinal direction, and the measuring device has a built-in timer;

[0011] The first sensor is used to detect the falling weight, and the measuring device triggers the instruction to start timing according to the feedback of the first sensor.

[0012] The second sensor is used to detect the falling weight, and the measuring device triggers the instruction to stop timing according to the feedback of the second sensor.

[0013] The measurement device is used to calculate the moment of inertia of the object to be measured according to the time counted by the timer and the moment of inertia formula of the rotor.

[0014] The first sensor and the second sensor are arranged on the end side of the platform through a sensor bracket.

[0015] The above-mentioned sensor bracket is C-shaped.

[0016] The above-mentioned heavy object is a 1 kg weight.

[0017] The above-mentioned rotating shaft bracket is n-shaped, and a semi-circular arc groove is provided on the top surface for embedding the bearings or rotating objects at both ends of the rotating shaft.

[0018] Furthermore, two parallel sliding grooves are provided on the top surface of the above-mentioned platform. The cross-section of the sliding groove is T-shaped and a nut is built in. The nut is used to fix the support feet of the rotating shaft bracket.

[0019] The above-mentioned measurement device is fixedly arranged on the top surface of the platform through a bracket.

[0020] The beneficial effects of the present utility model are as follows:

[0021] A moment of inertia testing device of the present utility model is based on the falling weight method, which converts the potential energy of the heavy object into the rotational energy of the rotor and the kinetic energy of the heavy object. The device has a simple structure, is easy to operate, has a low cost, has a good detection effect, the detection principle is intuitive and easy to understand, it is easy to understand and explain the measurement process, helps students and non-professionals to deeply understand relevant physical concepts, and has strong practicability and wide applicability. Description of the Drawings

[0022] Figure 1 It is a schematic structural diagram of the testing device of the present utility model.

[0023] Figure 2 It is an application structural diagram of the testing device of the present utility model.

[0024] The meanings of the marks in the drawings are as follows: 1. Platform, 2. Rotating shaft bracket, 3. Groove, 4. Sliding groove, 5. Sensor bracket, 6. Second sensor, 7. Measurement device, 8. Object to be measured, 9. Bearing, 10. Disc, 11. Rope, 12. Weight. Detailed Embodiments

[0025] The present utility model will be specifically introduced below in conjunction with the drawings and specific embodiments.

[0026] A moment of inertia testing device is composed of a platform 1, a rotating shaft, a rotating shaft bracket 2, a sensor, and a measurement device 7.

[0027] Two parallel sliding grooves 4 are provided on the top surface of the platform 1. The cross-section of the sliding groove 4 is T-shaped, and a nut is embedded in the sliding groove 4.

[0028] The rotating shaft support 2 is in an n shape, and the two support feet are respectively fixed to the nuts in the two chutes 4 with bolts. That is, a pair of rotating shaft supports 2 are parallel to each other, fixed by nuts and can slide along the chute 4 according to requirements to change the distance of the bearing 9 support, so as to adapt to different objects to be measured 8 and improve the versatility of the moment of inertia testing device. The top surface of the rotating shaft support 2 is provided with a semi-circular groove 3.

[0029] The sensor support 5 in a C shape is longitudinally arranged at the end side of the platform 1. The first sensor is fixedly arranged at the top end of the sensor support 5, and the second sensor 6 is fixedly arranged at the bottom end of the sensor support 5. The first sensor and the second sensor are respectively connected to the measuring device 7, and the measuring device 7 is connected to a timer.

[0030] During use,

[0031] The object to be measured 8 is coaxially fixed with the rotating shaft. Bearings 9 or rotating objects are respectively arranged at both ends of the rotating shaft and placed in the semi-circular groove 3. On the outer side of the bearing 9, that is, the extended part of the rotating shaft end extends out of the platform 1, and a coaxial light disc 10 is arranged on the extended part outside the platform 1. A thin rope 11 is wound around the disc 10 for several turns. One end of the rope 11 hangs a 1KG weight 12, and the other end is fixedly connected to the disc 10.

[0032] Release the weight 12, and it will fall under the action of gravity and drive the rotating shaft and the object to be measured 8 to rotate.

[0033] The first sensor first detects the falling weight 12 and feeds it back to the measuring device 7. The measuring device 7 triggers the timer to start timing according to the feedback.

[0034] The weight 12 continues to fall, and the second sensor detects the falling weight 12 again and feeds it back to the measuring device 7. The measuring device 7 triggers the timer to stop timing according to the feedback and obtains the timing time; after repeating multiple times, the average value t is obtained.

[0035] Then, the measuring device 7 calculates the moment of inertia of the rotor, that is, the moment of inertia of the object to be measured 8, according to the formula J = mr 2 {gt 2 / 2h - 1},

[0036] In the formula: J is the moment of inertia of the rotor (kg·m 2 ), M is the mass of the suspended heavy object (kg), r is the diameter of the place where the thin rope 11 is wound on the disc 10 (m), h is the height that the heavy object drops (m), g is the acceleration due to gravity (m / s 2 ), and t is the time required for the weight 12 to drop the height h (s).

[0037] Preferably, the measuring device 7 can be fixedly arranged on the tabletop of the platform 1 with a bracket and integrated with the platform 1.

[0038] Preferably, to reduce the resistance of the bearing 9 or the rotating object during rotation, grease can be used.

[0039] Preferably, the material of the sensor bracket 5 can be selected as ABS (acrylonitrile-butadiene-styrene copolymer) material, which has characteristics such as wear resistance and chemical corrosion resistance, and reduces the overall weight of the device.

[0040] Preferably, the first sensor and the second sensor can be selected as photoelectric sensors.

[0041] Preferably, the measuring device 7 can be connected to a display to display the measurement results in real time.

[0042] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the above embodiments do not limit the present invention in any form. Any technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims

1. A moment of inertia testing device, characterized in that: It includes a pair of rotating shaft brackets arranged on the platform, and the rotating shaft brackets are used to fix the rotating shaft of the object to be tested; The end of the rotating shaft is provided with a disc around which a thin rope is wound, and the other end of the thin rope is vertically connected to a weight; The end side of the platform is provided with a first sensor and a second sensor connected to a measuring device along the longitudinal direction, and the measuring device has a built-in timer; The first sensor is used to detect the falling weight, and the measuring device triggers the instruction to start timing according to the feedback of the first sensor. The second sensor is used to detect the falling weight, and the measuring device triggers the instruction to stop timing according to the feedback of the second sensor. The measuring device is used to calculate the moment of inertia of the object to be measured according to the time counted by the timer and the moment of inertia formula of the rotor.

2. The testing device according to claim 1, characterized in that: The first sensor and the second sensor are arranged on the end side of the platform through a sensor bracket.

3. The testing device according to claim 2, characterized in that: The sensor bracket is C-shaped.

4. The testing device according to claim 1, characterized in that: The weight is a 1 kg weight.

5. The testing device according to claim 1, characterized in that: The rotating shaft bracket is in an N-shape, and a semicircular arc groove is provided on the top surface for embedding bearings or rotating objects at both ends of the rotating shaft.

6. The testing device according to claim 5, characterized in that: The top surface of the platform is provided with two parallel slide grooves, the cross section of the slide groove is T-shaped, and a nut is built in; the nut is used to fix the supporting foot of the rotating shaft bracket.

7. The testing device according to claim 1, characterized in that: The measuring device is fixed on the top surface of the platform through a bracket.

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