The Design Of Driving System For Polar Deep Ice Drill

The driving system for polar deep ice drill reduces the high speed of the motor to the speed suitable for the ice drill through the reduction device,and drives the lower drill tool to rotate.At the same time,the pump is driven to realize the reverse circulation of drilling fluid at the bottom of the hole to remove ice debris.In this work,to improve the performance of the driving system of the electromechanical drill,the driving system of the ?127 cable-suspended electromechanical coring drill is researched.Planetary gear drive and harmonic gear drive were used in the previous reduction transmission devices of the drill.During the meshing process of each pair of planetary gears,each pair of gear teeth was prone to fatigue damage due to the interaction vibration between the teeth.In addition,the high torque would cause the destruction of the reduction transmission,and owing to the relatively short life,the reliability of the device would be poor.The flexible gear and bearing of harmonic reducer are prone to fatigue failure,and the high load will lead to the short solid lubrication and wear-resistant life of tooth surface.Therefore,the reliability of the reduction transmission device of the ?127 cable-suspended electromechanical coring drill studied in the past is poor.In view of the above problems,a new type of reduction transmission mechanism,namely movable teeth transmission reduction device,is proposed in this paper.The movable teeth drive structure is compact and the transmission ratio range is wide enough to meet the characteristics of small diameter and large transmission ratio of ice drill.The multi-teeth meshing bearing capacity is strong,the transmission efficiency is high and the service life is long enough to meet the characteristics of large vibration intensity and reliability of polar drill.The rolling movable teethreducer is applied to driving system of polar ice drill.The rolling movable teeth transmission is a kind of multi-teeth meshing transmission,which can distribute the torque of the reducer to multiple tooth,and the torque of each teeth is greatly reduced,thus greatly improving the life of the reducer.More than half of the movable tooth mesh,making the impact resistance and load-bearing capacity of the device strong.In this paper,based on the basic parameters and geometric dimensions of the rolling movable teeth reducer,the center gear profile of the reducer is designed.In the process of tooth profile design and drawing,the basic parameters and geometric dimensions are modified again,and the tooth profile design and parameter determination are staggered to meet the design requirements of the drill.The sliding rate of the reducer are also studied in this paper.According to the structure parameters of the rolling movable teeth reducer,the working characteristics of the ice drill and the overall disassembly and assembly structure relationship,the structure of the driving system of the ? 127 cable-suspended electromechanical coring drill is designed in this paper,and lubrication characteristics of the system are also studied.In this paper,the mechanical analysis,reliability analysis and optimization of the rolling movable teeth reducer are carried out.(1)The mechanical analysis of the main load-bearing components of the movable teeth transmission reducer,such as the center wheel,the rollers and the eccentric wheels,is carried out,and the strength of the meshing components is calculated according to the force analysis value.Through strength checking,it is determined that the strength of the device meets the requirements of operation.(2)Through ANSYS Workbench,the static and dynamic analysis of the rolling movable teeth reducer is carried out.From the stress and strain nephogram of the whole device and the main load-bearing components,itcan be seen that the maximum stress of each component is less than the yield strength and tensile strength set by each material,and the maximum strain meets the requirements of stiffness,which will not cause the operation failure of the reduction transmission device and meet the design requirements of the reduction transmission device.According to the modal vibration pattern and vibration frequency,the natural frequency of the reducer is higher than the excitation frequency of the reducer,and there is no resonance.The deformation of the tooth rack is larger and the stiffness is smaller,mainly because the tooth rack is a thin-walled structure,so the wall thickness of the tooth rack can be increased appropriately or the material with greater stiffness can be replaced.The input shaft is prone to bending vibration,so the stiffness of the input shaft bearing should be increased.(3)According to the foregoing research,the input shaft of the rolling movable teeth reducer is the weak link of the reliability of the reducer.It is found that the input end of the input shaft is prone to fatigue damage.In this paper,the reliability of the input shaft of the reducer is discussed by using the Six Sigma Analysis module in ANSYS Workbench.The response surface graph based on the random sample points generated by the reliability analysis system reflects that the maximum stress on the input shaft is the smallest when the diameter of the input end of the input shaft is the largest.According to the maximum stress probability list of the input shaft,the maximum stress of the input shaft is 260.81 MPa larger than the output variables,and the reliability of the input shaft is 100%.Therefore,the reliability of the input shaft of the reducer meets the design requirements.