Simulation of drive power in mechatronic systems

The results of research on determining the parameters and circuit solutions of traction drives of funicular cars are presented in this paper. As a result of the research, it has been revealed that the funiculars, the bodies of which have an articulated joint, possess the greatest advantages. It is effectually to use three-phase AC machines with permanent magnets as traction electric motors. The mechanical part of the drive must contain a speed transformer with a gear rack-wheel type gearing. The wheels of the running gears perform the function of holding the car on the track structure. The traction force is performed in a gearing, the rack of which is placed between the rails of the track structure. The given method for calculating the power of the drive motor made it possible without question to determine its dependence on the angle of inclination of the railroad bed.

Analysis Of Tip Relief Profiles For Involute Spur Gears

The main goal of this research was to study the influence of involute spur gear tip relief on the contact stress at the engagement meshing point (the begining point of the line of contact A). Different predefined involute spur gears and modification parameters (amount and length of modification) were already available from previous studies (Schmidt 2019). In this study, both the drive and the driven gear has tip relief. The modification of the gear profile was achieved through the modification of the gear rack cutter’s profile. This way the profil modification of the gear profiles are generated during the gear generation (gear planning) process. The gears have been nitrided, so after the gear manufacturing process, the heat treatment did not defrom the modified gear profile. The gear modifications were generated in a CAD system, and the calculations were made with FEM. The results show that the tip relief influences the magnitude of the gear contact stress at the first meshig point. With the use of tip relief modification, the contact stress of the meshing gears can be reduced at the beginning of the meshing line.

Fine module hobs for processing cylindrical involute gears

Aspects of formation of a hobs cutting part for processing of gear wheels are considered. In the traditional manufacture of hobs for processing the rear surfaces of cutting teeth, the process of radial or oblique relieving is used, which due to its dynamic nature associated with reciprocating motions of a grinding head with a grinding wheel installed thereon, makes it difficult to ensure high accuracy of teeth pitch and profile, as well as main hob parameters. These shortcomings are effectively eliminated by using the process of screw relieving to process the lateral rear surfaces of the hob teeth. Execution of a hob teeth profi le in the form of a gear rack enables to obtain a hob for processing gear wheels. A number of formulas are given, by means of which it is reasonably proved that hobs made using the considered principle of formation of teeth back surfaces can have a high class of accuracy — AA or AAA. Calculations showed that the displacement of the hob teeth at two revolutions of the main worm screw with a probability of 0.9973 does not exceed 0.13 μm, which is signifi cantly higher than the requirements of GOST 10331-81 for hobs with AAA accuracy class (not more than 4 μm for hobs with a pitch over 0.5 to 0.9 mm). The considered method of forming the hob rear surfaces in the form of counter right and left multi-turn screw surfaces (screw relieving) allows to obtain hobs not only for machining involute gears, but also other types of cutters, e.g. for machining threads, ratchet wheels and other parts having a regular profile.

Analysis of starting in horse head system at optimal jerking mode of movement

This article presents the results of an analytical study of the kinematic and power parameters of the movement of the articulated boom system of the crane at the beginning of the movement. The study was carried out during the acceleration of the electric motor of the mechanism for changing the departure from the state of rest to the rotation frequency corresponding to the nominal operating speed of the load movement. In this case, the start of the electric motor occurs, provided that the entire boom system moves along with the load according to the law of jerking optimization. The using of this regularity allows you to completely smooth out the swinging of the load at the beginning of the movement. In addition, towards the end of the acceleration, the same speeds and accelerations are provided between the end point of the crane trunk and the load. This makes it possible to ensure high smoothness of movement of the boom system, and to avoid the load swinging after the rotor of the electric motor reaches the rated speed. Also, a study of static, dynamic and total force in the drive gear rack was carried out. These studies were carried out at different duration of the process of starting the electric motor according to the law of jerking optimization. This made it possible to establish the dependence of the studied kinematic and power parameters on the duration of the transient process. Based on the above, recommendations have been developed for choosing the duration of the acceleration of the electric motor in the mechanism for changing the departure. During of the study, graphs of changes in the studied parameters of the boom system in time were built. Graphical dependencies were obtained with the most acceptable duration of the acceleration mode from the point of view of reducing the dynamic loads on the links of the boom system, improving the technological process of the crane and its ergonomics.

Friction Stir Forming of Aluminum Alloy Gear-Racks with Semi-Closed Dies

This paper reports friction-stir forming (FSF) of gear-racks of JIS A5083 aluminum alloy with semi-closed dies. FSF is a modified friction-stir process suggested by Nishihara in 2002. The process generates frictional heat and internal forces, enabling massive deformation of the material. It has been successfully utilized for mechanical joining and microforming, but seems to offer an opportunity for net-shape forming of bulk products as well. We put a material in a semi-closed gear-rack die and conducted friction stirring on its top surface. The material deformed and filled the cavity of the die due to high pressure and heat caused by friction stirring. This study investigates the forming conditions and the corresponding results, including the material fill ratio in the tooth. We also investigated the difference between this method and open-type FSF that had been conducted with an open-die structure.

ПРОЕКТНО-КОНСТРУКТОРСЬКІ ОСОБЛИВОСТІ ПЛАНЕРУ РЕГІОНАЛЬНОГО ПАСАЖИРСЬКОГО ЛІТАКА

The design features of the regional passenger aircraft airframe, which were introduced at the stages of developing the An-148/An-158 aircraft family, are described. The design and construction works on the airframe, which were aimed at the implementation of the airframe design concept, based on the principle of a safely damaged structure, are given. The An-148/An-158 airplanes were designed using modern computer-aided design systems. The work performed provides aeroelastic stability for all configurations and all design conditions. When creating a family of regional passenger airplanes, a number of new design and technological solutions were applied to the airframe design (fuselage, wing, pylons of powerplants and tail assembly), in particular: the scope of composite materials (CM) application was expanded, including the fuselage beamstructural elements; auxiliary power unit compartment is made entirely of CM; fastening the skin to the fuselage frame is made using rivets with a compensator, which ensures high quality of the external surface and eliminates the need for milling the heads of rivets after their installation; the fuselage canopy frame was made by welding, which significantly simplified the assembly technology; a two-support connected hitch scheme and control of extension of the slat sections with the use of involute gearing in the slat extensionretraction drives on the hinge mechanisms in the form of a pair of gears – a gear rack; developed a rational design of the wing box with a theoretical surface of double curvature, high adaptability and operability with survivability and high lifetime; a seven-part flap extension-retraction mechanism has been developed, which provides a predetermined flap advancement path; a combined flap design with a metal torsion box part, nose and tail part and a deflector made of CM; a molybdenum coating was applied, which increased the wear resistance of high-loaded parts from titanium alloys by more than 20 times; a monolithic integral design of interceptors and ailerons from CM was developed; a rational design of a pylon of a hinge plate of a mid-flight power plant has been developed with optimal rigidity characteristics to achieve given characteristics of flutter safety, with extensive use of composite materials in the tail and nose sections; the design of caps from pressed semi-finished products with two tips has been developed; an integrated design of the rudder and elevator made of composite materials has been developed.

Novel Gear Transmission Mechanism With Twice Unequal Amplitude Transmission Ratio

The operation effectiveness of multi-bar transplanting mechanisms is low, and the specific changing law of the transmission ratio (the curve of the transmission ratio has twice unequal amplitude [TUA] fluctuation.), which is needed in vegetable pot seedling transplanting, is difficult to fulfill using a planetary gear train with noncircular gears and a single-planet carrier. To address this problem, we propose a noncircular gear pair that comprises an incomplete noncircular gear, rack, partial noncircular gear, and elliptical gear. The structural characteristics and the working principle of the TUA gear pair were analyzed. The pitch curve equation of the noncircular TUA gears was derived from the relationship of the angular displacement of the corresponding pitch curves. The influence of central angle α and eccentricity k on the shape of the pitch curve, angular displacement, and transmission ratio of the TUA gear pair was analyzed. The TUA gear pair was applied to a proposed vegetable seedling pickup mechanism (SPM) considering the design requirements. Finally, the feasibility of the new noncircular TUA gear transmission mechanism was verified by an SPM test.