Measuring device for measuring the center of mass, moment of inertia and product of inertia of objects

Abstract

A measuring device for measuring the center of mass, moment of inertia and product of inertia of an object, which includes a cross support arm composed of two symmetrically arranged leaf spring support arms and two symmetrically arranged knife-edge support arms; the cross support arm It is combined with the supporting seat by fixed connection, and the support seat is supported on the middle and upper part of the rotating vertical shaft of the vertical shaft system in a moving fit manner, and the upper end of the rotating vertical shaft is fixedly installed with a receiving plate; the knife-edge support The arm is placed on the machine base through the knife-edge sub-frame, and the horizontal extension ends of the two symmetrically arranged leaf spring support arms are respectively connected to the machine base through the leaf spring and the pressing block; a displacement sensor, the displacement sensor is connected with the lifting device, and the lifting device is combined with the machine base. The invention solves the difficult problem of integrated measurement of various parameters by completing the measurement of the center of mass, the moment of inertia and the product of inertia of an object on one piece of equipment, the measurement accuracy is obviously improved, and the measurement cycle is obviously shortened.

Description

technical field [0001] The present invention relates to a measurement device, in particular to a measurement device for measuring the center of mass, moment of inertia and product of inertia (vertical dynamic balance) of an object. Background technique [0002] The present invention is a continuation of Chinese patent ZL 00 1 15925.9. [0003] The above-mentioned patent discloses a measuring device for measuring the center of mass, centroid and deviation of the center of mass of an object, which includes a concentric and rigid connection combining a bearing plate and a rotating vertical shaft, and a power mechanism installed at the lower end of the rotating vertical shaft , the rotating vertical shaft is placed on the machine base through the cross support arm frame fixed on the support seat; the cross support arm is composed of two symmetrically arranged swing support arms located in the same horizontal axis direction and a It consists of two symmetrically arranged sensing...

AI Technical Summary

Problems solved by technology

This is a relatively long process, which means that its structural weakness leads to a long measurement cycle, which is also one of the bottlenecks restricting the technology

[0005] Second, the force sensor can only provide one-dimensional constraints, and the translational constraints of the shaft system are realized by the constraint mechanism arranged at the end of the knife edge. The friction force has a certain influence on the sensitivity of the knife edge, making it difficult to continue to improve the measurement accuracy

[0006] Third, due to the low frequency response of the load cell and the inability to provide translation constraints, its shafting cannot rotate at a high speed, generally only about 1 revolution per minute, so dynamic balance tests cannot be performed, and the product of inertia cannot be measured

The spring has relatively poor creep and plastic deformation phenomena, so the spring measurement accuracy of this structure is poor

At the same time, the circumferential displacement is replaced by tangential displacement, and there is also an error

Of course, it will take a certain amount of time to connect and disconnect.

[0008] Fifth, the swing amplitude of the spring structure decays quickly, and the number of measurable cycles is generally only about 5 times, which has a certain impact on the measurement accuracy

[0009] Sixth, since the circular oscillating axis system and the product rotating axis system are the same axis system, the measured object can only measure one-dimensional moment of inertia once placed, and the measurement in different directions must be artificially placed again along this direction

[0010] Seventh, the requirements of the center of mass measurement and the moment of inertia measurement on the shaft system lead to conflicts between design and machining assembly, and the process problems are prominent

Specifically, the measurement of the center of mass is based on the axis of rotation. Generally, it is necessary to pre-tighten the bearings after precision machining to ensure that the shaft system does not produce radial runout, while the measurement of the moment of inertia requires the shaft system to rotate very flexibly. To complete a set of It is very difficult to have a shaft system with no gap and flexible rotation, even if it can be adjusted to achieve its long-term stability, it is not good

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