MECHATRONIC CLAMPING MECHANISM WITH ELECTRO-HYDRAULIC ACTUATOR FOR MACHINE SPINDLE UNITS

The design of the clamping mechanism for fixing workpieces and tools in the spindle assemblies of machines that is equipped with an additional subsystem to provide the possibility of programmable settings to the required clamping force is presented. The electronic unit and electromechanical energy converters provide the possibility of reconfiguration by reprogramming the clamping mechanism according to the different tasks comparatively easily. The obtained results help to expand the functionality of clamping mechanisms, and consequently the functionality of machine tools and their technological flexibility.

Spindle assembly with adjustable output characteristics

A method for controlling the output characteristics of spindle assemblies based on the use of tapered gas bearings with a small taper angle is proposed. An experimental bench for studying the performance characteristics of these bearings is described. The results of researches of gas-static bearings with a small taper angle are presented. Keywords: spindle assembly, gas-static support, small taper angle, experiment. [email protected]

Forensic Engineering Analysis of a Wheel Spindle Failure Due to Pre-Load and Fatigue

Typically, most vehicles equipped with non-powered wheels use a spindle that not only supports the weight of the vehicle but also allows the rotation of the tire. The rotation of the hub and wheel on the spindle is accomplished with the use of either a tapered or double row ball bearing. Bearings are mounted between the spindle and hub/wheel assembly, then secured with a castle nut set to a specified torque. Tapered bearings are chosen for this application because they are designed for applications where forces are generated radially (vertically) and axially (laterally) during use. Although tapered bearings are ideally suited for use in wheel and spindle assemblies, they must be installed properly to perform as designed. As part of that installation, the spindle nut must be properly torqued in order to apply a sufficient pre-load to the tapered bearings. Without the proper pre-load, the bearings can either generate too much friction or ride improperly on the spindle, generating forces that are not properly distributed. This paper will discuss the failure of a spindle and wheel assembly that experienced fatigue due to improper pre-load of the spindle nut.

DETERMINATION OF VIBRATION POWER OF VIBRATION SOURCES OF SPINDLE UNITS OF METAL CUTTING MACHINES

Monitoring the state of spindle assemblies of modern metal-cutting machines using CIP methods implies the possibility of installing control sensors in places with maximum vibration information content. In this regard, the assessment of the informativeness of the vibration field of the spindle assembly, which can be carried out in advance, taking into account the design features, geometric and dimensional characteristics, is an urgent task. Based on the energy approach, using the example of the spindle assembly of a universal lathe, a computational model is proposed, built along the median planes of the walls. On the basis of the calculated model, the equations of the energy balance were compiled taking into account the conditions for the transfer of vibration power between the walls of the housing. The method for determining the vibration power of the main sources in the spindle assemblies is given: a spindle with residual unbalance, a drive gear and bearings. It has been established that the most significant factors determining the vibration power introduced into the spindle unit housing are the operation of the bearings, the weight of the spindle and the location of its center of mass. The result obtained makes it possible to detect incipient defects in the bearings, which, as practice shows, are the defining elements of the parametric reliability of spindle assemblies. The resulting model of the vibration field can be used to determine the reference values of vibration velocities that are formed from sources in the absence of defects.

REVIEW OF DESIGN AND FORECASTING THE QUALITY OF SPINDLE ASSEMBLIES WITH GASSTATIC SUPPORTS

Оптимальное проектирование сложных технических объектов невозможно без прогнозирования характеристик их работоспособности. Применяемые при этом методы многокритериальной оптимизации напрямую используют в качестве критериев выходные характеристики динамического качества, поэтому задача прогнозирования последних, в конечном счете, определяет качество проектирования. The optimal design of complex technical objects is impossible without predicting the characteristics of their performance. The multicriteria optimization methods used in this case directly use the output characteristics of dynamic quality as criteria, therefore, the task of forecasting the latter, ultimately, determines the quality of the design.