Thermal Characteristic Analysis Of Machine Tool Spindles For Static Pressure And Rolling Hybrid Bearings

Surface grinding is a kind of efficient and precise manufacturing process.At the present,the surface grinding is supported by rolling bearings,but it is affected by the vibration,noise and rotation precision of the rolling bearing.This supporting method cannot meet the requirements of the high-efficiency grinding spindle of large workpieces.Aiming at the development status of large-size end grinding spindles at home and abroad,this paper proposes a new large-size surface grinding spindle with water-lubricated hydrostatic thrust bearing and rolling bearing.As a kind of novel spindle system,it has important scientific significance and engineering value for modeling and analyzing the thermal characteristics under high-speed conditions.The specific content of this article is as follows(1)Thermodynamic Modeling of Spindles for Static Pressure and Rolling Hybrid Bearings: Thermodynamic modeling of new spindles is established.The main steps include the following part,establishing the power flow model of the spindle system based on tribology and heat transfer theory,calculating the heat source of the spindle system and calculating the thermal boundary conditions to establish the thermodynamic model of the hydrostatic and rolling hybrid bearing machine tool spindle;(2)Thermal Characteristic Analysis of Hydrostatic and Rolling Hybrid Bearing Machine Tool Spindle: Based on the thermodynamic model of the spindle in(1),the he thermal characteristics analysis is carried out,the temperature field and thermal displacement field of the spindle are analyzed and calculated,and relevant main parameters such as rotation speed?eccentricity/ water supply pressure/ and viscosity are studied.(3)Hydrostatic and Rolling Hybrid Bearing Machine Tool Spindle Thermal Characteristic Test Research: The thermal characteristics test of the above-mentioned spindle system is carried out.The main test content is to test the temperature rise of the self-aligning ball bearing,the bearing sealing surface and the bearing back water tank under different speed and pressure conditions.The results show that the model calculates the maximum temperature rise of the water-lubricated bearing at the design limit speed of 16000r/min to 1.8°C,the displacement of the shaft end to 5.5?m,and the oil-lubricated bearing of No.10 oil rises to 115°C at the highest temperature of 12000r/min.The end displacement was 49.4 ?m.After experimentalmeasurement,the spindle remains idling,and the highest temperature rises to 2.5 °C.The theoretical calculation results are basically consistent with the experimental measurements.The water-lubricated hydrostatic thrust bearing and the rolling bearing are supported by the end face grinding spindle.The heat generated by the spindle is much smaller than that of the conventional grinding machine spindle,and it is expected to be applied to the end grinding machine.