Enhancement of Machining Accuracy Utilizing Varied Cooling Oil Volume for Machine Tool Spindle

Abstract

In this study, varied cooling oil volume (VOV) control was developed for the oil coolant of a machine tool. This allows adjustment of the oil circulation flow rate in terms of the machining loads and rotational speeds of the spindle to remove the generated heat effectively from the spindle. A mathematical model of the cooling oil flow rate in terms of the rotating speed and torque of the spindle for VOV method is developed. From the thermal deformation experiments with the VOV method, the thermal deformations in both the Y-axis and Z-axis can be greatly reduced, by 70.1 % and 73.5 %, respectively, in variable rotational speed operation with a short operational period (10 minutes). Moreover, the VOV method was applied to shorten the required warm-up time of the spindle. The required warm-up time of the spindle can be shortened by 50 %, while the three axes of the spindle attain stable thermal conditions. In practical machining experiments, the machining accuracy with the VOV method can be greatly enhanced by 34 % to 62 % in comparison with the current case of constant cooling oil volume (COV). The VOV control system in the machine tool spindle can effectively reduce the thermal deformation and shorten the required warm-up time. In addition, the machining accuracy can be greatly enhanced. INDEX TERMS Thermal deformation, thermal suppression, varied cooling oil volume, machining accuracy.

Atomistic Full-quantum and Full-band Transport Model for Zigzag Group-IVA Nanoribbon-based Structures with Noniterative Calculation Framework

“…The van Hove singularities occur where the derivative of the DOS with respect to energy E diverges, which yields a strikingly sharp peak in the DOS spectra. (38)(39)(40)(41)(42)(43) Therefore, in a perfect flat-band z4ANR, the DOS diverges at the onset of each subband, as shown in Figs. 5(a) In quantum transport devices such as DBSs, a series of discrete and fine confined levels (or states) exist in the central channel, and a continuous distribution of states exists in the left and right contacts.…”

Cooling of motor spindles—a review

“…One approach is compensation, which also includes the cooling techniques discussed in this paper. The application of special materials (e.g., [44,45]) and targeted heating (e.g., [46,47]) as well as design adaptions (e.g., [48,49]) are also assigned to compensatory measures. Another approach is the application of corrective measures.…”

Increase in Accuracy of a Built-in Spindle by Adaptive Cooling Control with Varied Coolant Volume and Temperature

“…The temperature of the circulating coolant is reduced in the plate heat exchanger, and the low-temperature coolant is pumped to the rotating spindle to remove the heat generated in the operational process. (12,13) In this study, the ambient temperature was treated as the reference temperature for the return coolant. The coolant temperature sensor at the inlet of the plate heat exchanger instantly responds to the inverter of the compressor to adjust the refrigerant flow rate in the refrigeration cycle in accordance with the cooling load variation of the spindle.…”

“…It was found that the heat transfer coefficient was increased by increasing the surface roughness. Li et al (12,13) performed multiphysics simulation analysis on the cooling channel design of a built-in spindle. The design of experiments (DOE) method was employed to optimize the dimensions of the cooling channel, and practical machining experiments were performed to validate the thermal performance of the design.…”