Modernization of mini-tractor for wood skidding

The work was carried out in three directions: changing the rotation system of mini-tractor, installing remote control of the winch and improving the trailer. The modernization of the mini-tractor in all directions was successfully completed, and the research results were patented. Testing of the improved mini-tractor in real working conditions confirmed our expectations. Replacing the rotary mechanism with steering, installing the driver’s seat significantly reduced operator fatigue when wood skidding. Remote control of the winch reduced the time of wood loading on the trailer by 1.7 times compared to the option without using it. The total time to perform entire technology cycle from cutting trees to loading them on the trailer, skidding and unloading is decreased by 19.4%. Changing the design of the trailer allows to exclude the turn of the tractor train along the skidroad with penetration into the forest and facilitate the loading of harvested timber.

Design and Error Compensation Performance of a Precision Micro-Drive Rotary System

In order to obtain motion with large travel and high precision, the micro-drive system is used to compensate for the motion error of the macro-drive system in the macro/micro dual-drive system. The research on the micro-drive rotary system lags behind the micro-drive linear system, so it is of great significance to study the designing and error compensation performance of a precision micro-drive rotary system. In this paper, a precision micro-drive rotary system is designed, the error compensation scheme of the system is proposed, and the system feasibility in design and error compensation is tested by FEM simulation analysis and performance experiments. Firstly, a precision micro-drive rotary system is designed to provide high-precision rotary motion, which consists of a micro rotary mechanism and PZT. In the system, the micro rotary mechanism is developed based on the compound motion principle of flexure hinge, which can accurately transform an input of linear motion into an output of rotary motion according to a certain relationship. Secondly, for finishing the error compensation scheme of the system, the maximum compensation modifier θ max ′ is proposed based on the analysis of error compensation equations of point-to-point motion and continuous motion. Finally, in order to facilitate the use of engineering, the driven voltage equation of error compensation is derived by the error compensation performance experiment. The simulation and experiment results indicate that both the design and error-compensation-range of the system satisfy the needs of practical application.

Effect of charge-transfer enhancement on the efficiency and rotary mechanism of an oxindole-based molecular motor

A novel oxindole-based light-driven molecular motor with pronounced push–pull character was investigated. The rotary mechanism stands in between the precessional motion of fluorene-based motors and the axial motion of biomimetic photoswitches.

Online measuring and estimating methods for the unbalancing vector of thin-disc workpiece based on the adaptive influence coefficient

The thin-disc part is the common part of the rotary mechanism. Because of the large rotating radius of the thin-disc part, the huge unbalancing vector may be formed even if the unbalancing mass is small. So, the unbalance of the thin-disc part is the important exciting factor of the rotary mechanism vibration. Based on the structural characteristics of the thin-disc part, the measuring and estimating methods for the unbalancing vector of the thin-disc workpiece are proposed based on the single-face influence coefficient method. The least square method is introduced to fit the fundamental frequency component from the vibration monitoring signal, and the fundamental frequency component is taken as the unbalancing vibration signal of spindle first. The influence coefficient between the trial weight face and vibration monitoring point on the spindle is tested by trial weight experiments second. The unbalancing vibration difference of the spindle, before and after the thin-disc workpiece is clamped, is monitored and used to estimate the unbalancing vector of the thin-disc workpiece based on the linear reversible principle of unbalancing excitation and vibration response. The signal separation accuracy of the least square method for unbalancing vibration has been proved by simulation and experiment methods. Considering that the accuracy of the influence coefficient may be influenced by the change of the spindle system kinetic characteristic parameters, the signal measurement, analysis error, etc., the adaptive method for the influence coefficient is proposed and proved by the experiment method in the article. The research results show that the unbalancing vector of the thin-disc workpiece can be measured and estimated before the workpiece is taken down from the machine tool spindle. The proposed method can be used to measure and estimate the unbalancing vector of the thin-disc workpiece without dynamic balancing machine, and the measuring efficiency and accuracy can be improved; the measuring cost can be reduced.

Measurement of the Effect of Controlling Parameters on Performance of Abrasive Jet Machine

Abrasive Jet Machine (AJM) widely used for cutting brittle materials. The present study focus on experimental investigation for performance parameters like Material Removal Rate (MRR) and Surface Roughness (SR) with variation in controlling parameters. Here, air pressure, abrasive particle temperature and speed of mixing chamber considered as controlling parameters for measurement of their effects on performance parameters of AJM. Compare to conventional method of AJM, unique feature of heating jacket and rotary mechanism provided in the newly developed AJM for experimental purpose. Experimental results reveal that the MRR and SR gets increased with increase in pressure, temperature and speed of mixing chamber.

A processive rotary mechanism couples substrate unfolding and proteolysis in the ClpXP degradation machinery

The ClpXP degradation machine consists of a hexameric AAA+ unfoldase (ClpX) and a pair of heptameric serine protease rings (ClpP) that unfold, translocate, and subsequently degrade client proteins. ClpXP is an important target for drug development against infectious diseases. Although structures are available for isolated ClpX and ClpP rings, it remains unknown how symmetry mismatched ClpX and ClpP work in tandem for processive substrate translocation into the ClpP proteolytic chamber. Here, we present cryo-EM structures of the substrate-bound ClpXP complex from Neisseria meningitidis at 2.3 to 3.3 Å resolution. The structures allow development of a model in which the sequential hydrolysis of ATP is coupled to motions of ClpX loops that lead to directional substrate translocation and ClpX rotation relative to ClpP. Our data add to the growing body of evidence that AAA+ molecular machines generate translocating forces by a common mechanism.

Trencher equipment

The article reflects the results of theoretical studies aimed at improving the equipment of the chain trencher. The proposed design allows the development of trenches on the sides of the pipeline. In addition, with the help of a cutter drum equipped with a rotary mechanism, the equipment removes soil from under the repaired pipe section. To confirm the health of the proposed technical solution, calculations were made of the power of consumption on the drive chain of the work equipment and cutter drum. When developing the design, calculations were made to determine the diameter of the shaft and check the splined joint for crumpling.