Measurement device for measuring object centroid, rotational inertia and product of inertia

Abstract

A measurement device for measuring object centroid, rotational inertia and product of inertia comprises a cross-shaped supporting arm composed of two plate spring supporting arms arranged symmetrically and two blade supporting arms arranged symmetrically. The cross-shaped supporting arm is fixedly connected with a supporting seat supported on the upper middle part of a rotary vertical shaft of a vertical shaft system in a movable fit mode, and a material bearing tray is fixedly connected with the upper end of the rotary vertical shaft. The blade supporting arms are erected on a machine base through a blade sub-frame, horizontal extension ends of the two plate spring supporting arms arranged symmetrically are connected with the machine base respectively through plate springs and compression blocks, and displacement sensors are arranged below the plate spring supporting arms and connected with a lifting device combined with the machine base. By means of the measurement device, measurement on object centroid, rotational inertia and product of inertia can be achieved through one device, the problem caused by integrated measurement of multiple parameters can be solved, measurement accuracy is improved remarkably, and a measurement period is shortened remarkably.

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

Images