Design Theory And Experimental Study On Ultrasonic Vibration Lapping Machining System Of Spiral Bevel Gear

The lapping technology has been widely used in the finish machining of tooth surface of spiral bevel gears.The traditional lapping process combined with ultrasonic vibration machining technology,thus forming the ultrasonic lapping composite processing method,can give full play to the characteristics of the traditional lapping process and the advantages of ultrasonic vibration machining,improve the lapping machining efficiency and tooth surface precision,reduce the vibration and noise of gear transmission,and improve the processing quality of spiral bevel gears.The design method of ultrasonic lapping vibration system is the key to realize ultrasonic lapping compound machining technology.The research object of this paper is the ultrasonic vibration lapping machining of medium modulus bevel gear,the medium modulus bevel gear is combined with ultrasonic horn to form an organic whole,the theory of flexural vibration and longitudinal vibration is used to study the design methods of ultrasonic lapping vibration system of gear and pinion respectively.Its main research contents and innovations include:(1)The design method of gear ultrasonic lapping vibration machining system with longitudinal-longitudinal-flexural vibration mode is established.The gear is simplified into the shape of a medium-thick circular plate,and combined with transferring vibration cylinder and ultrasonic stepped horn to form an organic whole.The resonance design is carried out by using these theories of flexural vibration and longitudinal vibration,and the displacement continuous equation,internal force equilibrium equation and free boundary equation are derived.A unified solution model describing vibration mode,resonant frequency and dimension parameters of vibration system is established,and the flexural vibration form and vibration mode of gear vibration machining system are studied and analyzed.(2)The design method of pinion ultrasonic lapping vibration machining system with longitudinal vibration mode is established.The pinion is simplified into the shape of a cone,and combined with ultrasonic stepped horn to form an organic whole.The resonance design is carried out by using longitudinal vibration theory,and the frequency equation for analyzing longitudinal vibration characteristics of pinion vibration system is established.The parameters of the pinion vibration system are designed,and the vibration system of the pinion which improves the vibration output ability is studied.The influence of the structural parameters of the pinion on the dynamic characteristics of the vibration system is studied.(3)The method of improving vibration energy transmission efficiency and controlling coupling vibration generation is studied.The propagation characteristics of the ultrasonic longitudinal wave at the interface between the gear and horn are studied,and the propagation efficiency of ultrasonic vibration energy in vibration system is improved by increasing the diameter of the cylinder between the gear and the horn.A method of controlling coupling vibration of cylinder is proposed to reveal the influence of cylinder slotted parameters on dynamic characteristics of gear vibration system.(4)A design method of longitudinal vibration modal lapping transducer based on load characteristics is proposed.According to the equation of piezoelectric effect of sandwich-type lapping transducer,the unified wave equation describing the motion state of piezoelectric crystal stack and front back cover is derived.Based on the continuous vibration velocity,the equal internal force and boundary conditions,the frequency equation for analyzing the longitudinal vibration characteristics of the lapping transducer is established,the structural parameters of the transducer satisfying the longitudinal mode are solved,and the design method of the lapping transducer considering the light/heavy load characteristics is established based on the load working state of the lapping transducer.(5)According to the principle of impedance characteristic analysis,an impedance characteristic analysis system based on impedance analyzer is established.According to the principle of vibration characteristic test,the resonant characteristic parameter measurement system including acceleration sensor and data collector is established.The measurement of impedance characteristic parameters and vibration characteristic parameters of the vibration system of the gear and pinion lapping transducer,the gear ultrasonic horn,the gear and pinion lapping vibration system is carried out,which proves that the design of the ultrasonic lapping machining vibration system is reasonable.(6)The experimental equipment to meet the needs of ultrasonic vibration tooth processing is constructed and the experimental research is carried out.The meshing equation of tooth surface position and the position equation of vibration lapping tooth are established to realize the uniform lapping requirements of tooth surface.According to the V/H adjustment method,equal clearance control equation of tooth side is established.The ultrasonic lapping experiments of the gear resonance,the pinion resonance,and the gear and pinion simultaneous resonance are completed,and the feasibility of the design theory of the ultrasonic vibration lapping system is verified by measuring the tooth surface deviation,the pitch error,and the gear pair vibration and noise.