Small-sized inertial exciter
Technical field
The present invention relates to vibrator technical field and dynamic experiment field, specifically, kinetics model analysis relates to as driving source, or vibrator equipment or the device of control power are provided.
Background technology
Vibrator is attached on some machinery and equipment in order to produce the device of exciting force.Substantially contact can be divided into and contactless for structural excitation mode experiment.Conventional contact vibrator has mechanical type, electromagnetic type and electric-liquid type.The usual volume of this kind of vibrator is relatively big, and compared with model, its quality be can not ignore.Generally place when testing and be fixed on ground or testing stand, by a rigid connecting rod, the exciting force of periodic transformation is delivered to testee, bring it about forced vibration, obtain tested system point place displacement time transformation relation by signal picker, thus being calculated analyzing.The connecting rod adopted in said structure makes, being formed the additional support of additional stiffness and restriction vibration displacement amplitude on geodesic structure, easily to cause error during data acquisition so that result of calculation is difficult to meet the required precision of mould measurement, affects result of the test.
Current mould measurement is tested according to vibrator as driving source, its big pogoniasis is connected with exciting object, thus to being formed additional stiffness and additional support by geodesic structure, causing that test gained modal parameter error is bigger in some cases, it is difficult to meet the required precision of mould measurement.
Summary of the invention
It is an object of the invention to overcome the deficiency of existing laboratory vibrator, it is provided that a kind of can frequency modulation, to not produced small-sized inertial exciter adnexa rigidity and adnexa damping, convenient that arrange, less suitable in rigidity and frequency relatively low works mould measurement by geodesic structure.
The technical solution used in the present invention is as follows: a kind of small-sized inertial exciter, is made up of power system and machanical vibratory extracting-driving system.Direct current generator 1, by being fixed on chassis, is arranged on the speed reducing gear pair tooth 8 on motor output shaft and is sent to by power with the power transmission shaft 2 being placed on chassis, and power transmission shaft 2 is by support with being placed on chassis, and its two ends are symmetrically arranged with two exciting agencies;Exciting agency is by the rotating shaft 3 stood on chassis and is nested with in rotating shaft and the eccentric massblock 6 of synchronous axial system therewith is constituted, and rotating shaft 3 is vertical with power transmission shaft 2 and is in same level.Direction-variable power transmission is realized by bevel gear pair 5 between power transmission shaft 2 and rotating shaft 3.
Further, the PWM DC motor drive for controlling motor speed it is provided with between direct current generator and motor power.
Further, the eccentric rotor of two exciting agencies is arranged on same vertical.
Further, rotating shaft 3 is provided with for indicating current rotor actual speed to test the speed code-disc.
So, operationally, control system and control direct current generator, utilize gear and drive link to drive the eccentric massblock of two mass-adjustables to reversely rotate, the big reversely exciting force of one equity of the identical natural frequency of vibration of subjects obtained and directly contact, thus carrying out modal test.
In a kind of detailed description of the invention, eccentric mass rotor can embed additional mass, increases the relative size of exciting force, makes exciting effect reach optimum and make actuator have more universality.
Device volume provided by the present invention is little, light weight, is placed on effective object the impact of model modal parameter is negligible.Adopt the present invention, while producing the exciting force that the tests such as mode measurement, dynamic Property Analysis are required, PWM speed regulator knob rotating speed is utilized to realize the continuous rotating speed of motor is controlled, have easy to control, volume is small and is easier to the new features being connected in different subjects, has higher motility
Accompanying drawing explanation
Fig. 1 is the front view of excitation system.
Fig. 2 is the top view of Fig. 1.
Fig. 3 is the left view of Fig. 1.
Fig. 4 controls system principle diagram.
Fig. 5 is the outside drawing of quality adjustable rotor.
Fig. 6 is the sectional view of Fig. 5.
In figure: 1. motor, 2. power transmission shaft, 3. rotating shaft, 4. speed reducing gear pair, 5. bevel gear pair, 6. eccentric rotor, 7. bearing, 8. connection holes, 9. bearing.
Detailed description of the invention
Below in conjunction with drawings and Examples, the invention will be further described, and embodiments of the present invention include but not limited to the following example.
By Fig. 1-3 it can be seen that, in excitation system, direct current generator 1 is fixed on chassis by two fixed supports 7, and speed reducing gear pair is arranged between machine shaft and power transmission shaft 2, changes the maximum output speed of motor to coordinate.Power transmission shaft 2 is fixed by two supports being fixedly arranged on chassis 9.At power transmission shaft 2 two ends, one bevel gear pair 5 is respectively installed, changes transmission direction with two rotating shafts 3, the big reversely exciting force of transmission one equity.Eccentric rotor 6 is arranged in rotating shaft 3, and two rotating shafts are in same level, four supports 9 support.
When system quiescence, two eccentric rotor 6 centers of gravity should be passed through to regulate bevel gear pair 5 and be located at same level line, control both initial phases identical.
By Fig. 4 it can be seen that, in control system, PWM DC motor drive is connected between direct current generator and motor power, control motor speed.
Can installing the code-disc that tests the speed in rotating shaft 3, code-disc output signal is connected on tachoscope and measures current rotor actual speed, it is possible to accurate quick realizes the frequency sweep work in modal test.Improving as one, eccentric rotor is provided with the connection holes 8 of differently configured mass, rotor can be inserted into different quality block to change exciting force size, thus adapting to the model of the different natural frequency of vibration.
During specific experiment, vibrator will be assembled, it is placed in tested model (such as simply supported beam model bridge floor) central authorities, it is connected by electric wire with power-supply system with arrangements for speed regulation, the single order natural frequency of vibration is calculated through theory, regulate rotor speed circular frequency to reach to carry out modal test near the theoretical natural frequency of vibration, can conveniently obtain the test single order natural frequency of vibration and other modal parameters.
Above small-sized vibrator provided by the invention being described in detail, apply specific case and principles of the invention and embodiment are illustrated, the explanation of above example is only intended to help to understand the core concept of the present invention.It should be pointed out that, for those skilled in the art, under the premise without departing from the principles of the invention, it is also possible to the present invention carries out some improvement and modification, these improve and modify in the protection domain also falling into the claims in the present invention.