Session: 04-02-02: Advances in Aerodynamics & Novel Aerospace Propulsion Systems

Paper Number: 76866

Start Time: Tuesday, 11:05 AM

76866 - Efficient Adaptive Gear Variator for the Drive of Aerospace Equipment 

The adaptive drive contains a motor and a two-mobile gear variator.

The kinematic chain of a gear variator with two degrees of freedom and with one input can have definiteness of movement only if there is an additional mobile-limiting force constraint. The article presents a kinematic and force analysis of two-mobile adaptive mechanisms and outlines the principle of definability of motion.

The object of research is a gear kinematic chain with two degrees of freedom with one input and one output, capable of performing the function of a gear variator (automatic transmission). The main requirement for the drive of aerospace equipment is simplicity of design, small size and weight in the presence of power adaptation to variable load. This is achieved by using the author's discovery of the effect of force adaptation in a two-mobile kinematic chain.

The paper investigates the possibility of creating an effective adaptive gear variator by ensuring the definability of movement with the help of an additional movable force constraint. This constraint ensures the existence of a gear variator in the steady-motion mode with equal work at the input and output.

The initial kinematic chain of a fundamentally new mechanism with two degrees of freedom and one input contains a rack 0, an input driver H₁, a movable closed chain with gears 1-2-3-6-5-4 and an output driverH₂. A closed chain with zero mobility contains an input satellite 2, a block of solar wheels 1-4, a block of ring wheels 3-6 and an output satellite 5. The drivers H₁ and H₂ are the initial links of the mechanism. The initial links can have specified angular velocities w_H1  and  w_H2 and specified moments of forces  M_H1 and M_H2. The input moment M_H1 is constant, the output moment  M_H2 can take different values within a given range.

A duplicate direct transmission from the input driver H₁ to the output satellite 5 in the form of gears 8 and 7 is added to the initial kinematic chain, providing definability of movement.

The presented two-mobile scheme of the mechanism with a mobile closed loop allows you to build a plan of linear speeds according to the specified speeds of the two initial links and bring the acting forces to the intermediate link 5.  The equilibrium of the kinematic chain in the steady-state motion mode corresponds to the equilibrium of link 5 with the forces applied to it.

Theorem 1 on a closed contour.

A kinematic chain with two degrees of freedom, containing an input link, an output link and a mobile closed loop placed between them, is able to exist in a steady-state mode of motion.

Theorem 2 on the definability of motion.

The determinability of the motion of a kinematic chain with two degrees of freedom is provided by an additional mobile-limiting constraint of moment with angular velocity in the form of a function of power.

The condition of a force interaction: M_H1w_H1=M_H2w_H2+P_S. Here P_S - power spent for overcoming of the elastic moment M_S.

From here w_H2=(M_H1w_H1-P_S}/M_H2 - the formula of force adaptation of output angular velocity w_H2 to a variable moment of resistance M_H2. Efficiency e=(M_H1w_H1-P_S)/M_H1w_H1.

The two-mobile mechanism with one input has a fundamentally new property of force adaptation. The absence of a control system in the drive greatly simplifies the design of the adaptive mechanism and increases its reliability.

 

Presenting Author: Konstantin Ivanov Almaty University of Power Engineering and Telecommunication

Authors:

Konstantin Ivanov Almaty University of Power Engineering and Telecommunication