Design And Research Of Oil-air Lubrication Test Rig For High Speed Angular Contact Ball Bearings

Angular contact ball bearings are the main supporting elements of the high-speed motorized spindle.The bearing failure is mainly caused by the friction heat under high-speed condition.Oil-air lubrication is a new cooling and lubricating technology,it has become the main lubrication method of angular contact ball bearings.However,due to the complex and variable operating conditions of the motorized spindle,the friction heating is still the main obstacle to improve the speed,accuracy and life of the angular ball bearing in the high-speed motorized spindle.Therefore,it is necessary to study the oil-air lubrication for angular contact ball bearing.In this paper a test rig for high speed angular contact ball bearings under oil-air lubrication was designed,it will provide the experimental basis for the study of oil-air lubrication of high speed angular contact ball bearings.The main contents are as follows:According to the actual working condition of angular contact ball bearings in high-speed motorized spindle,the function and design requirements for high speed angular contact ball bearings are determined,the overall design scheme of the test rig is developed.The test rig is composed of test bearing structure,oil-air lubrication system,drive system,measurement and control system,cooling system,loading system and so on.The test structure of the test bearing,the installation of the sensor and the oil-air lubrication nozzle are designed in details.According to the requirements of the experiment,the test and control system is designed.The function and model of temperature sensor,pressure sensor and color sensor in the test system are determined;the function and model of oil-air lubrication system controller,high speed motorized spindle,frequency converter and cooling system are determined.Based on the electromagnetic theory,a non-contact electromagnetic loading device is developed,which can provide axial load and can also provide radial load for the test bearings.The electromagnetic loading device is mainly composed of electromagnetic core,magnetic ring,lead rail and so on;the electromagnet core structure is composed of U silicon steel sheet and coils;the magnetic ring is designed as a ring configuration,The material selects iron nickel alloy with high permeability;The lead rail is designed as a lead rail by dovetail cast iron.The electromagnetic loading device realizes the non-contact loading for the test bearings,and to a great extent,reduces the vibration caused by high speed motorized spindle leads to inaccurate of test results.