Analysis of the parameters of the double clutch drive with reduced control energy consumption

The global trend of improving vehicle and traction transmissions is associated with the use of robotic preselector gearboxes, an important component of which is the friction clutch. The review of existing designs and analysis of clutch development concepts allows determining the directions of their improvement, in particular, the improvement of dry double clutches, which is the subject of research in this paper. A significant disadvantage of existing dual-clutch designs is the use of additional special (mostly hydraulic or combined) systems for on-off friction pairs, so the structural cost and energy costs for control are increased, and the design, maintenance, and repair are complicated. The proposed design of the drive to control the original dry dual-clutch involves a lever mechanism with the use of rotary stops, which are made in the form of mobile carriages with rollers, this provides switching clutches in a short time and actually without interruption of power flow, so the acceleration dynamics of vehicles will be improved, the clutch design will be simplified and energy consumption for its control during the start and gear shifting will be reduced. The mathematical model of the proposed clutch drive on the basis of which the control mechanism operation is simulated and influence of its design parameters on operational indicators of the clutch drive, in particular, on kinematic characteristics of the drive, ranges of kinematic and power gear ratios, the power interaction of the mechanism links, the power of the actuator when each clutch is turning on. It is established that the switching of clutches requires less energy, the movement of the mechanism elements is different, and the compression force of the friction pairs when starting the first and second clutches is different. The simulation results confirm that the proposed original lever design of the clutch control mechanism is effective. The obtained results allow us to reasonably determine the parameters of a clutch, but the choice of optimal-rational parameters of its control mechanism requires further research, for which appropriate methods, search algorithms, and their software implementation have been developed.

Towards a global perspective for Salvia L: Phylogeny, diversification, and floral evolution

Premise of this study: Salvia is the most species-rich genus in Lamiaceae, encompassing approximately 1000 species distributed all over the world. We sought a new evolutionary perspective for Salvia by employing macroevolutionary analyses to address the tempo and mode of diversification. To study the association of floral traits with speciation and extinction, we modeled and explored the evolution of corolla length and the lever-mechanism pollination system across our Salvia phylogeny. Methods: We reconstructed a multigene phylogeny for 366 species of Salvia in the broad sense including all major recognized lineages and numerous species from Iran, a region previously overlooked in studies of the genus. Our phylogenetic data in combination with divergence time estimates were used to examine the evolution of corolla length, woody vs. herbaceous habit, and presence vs. absence of a lever mechanism. We investigated the timing and dependence of Salvia diversification related to corolla length evolution through a disparity test and BAMM analysis. A HiSSE model was used to evaluate the dependency of diversification on the lever-mechanism pollination system in Salvia. Key Results: Based on recent investigations and classifications, Salvia is monophyletic and comprises ~1000 species. Our inclusion, for the first time, of a comprehensive sampling for Iranian species of Salvia provides higher phylogenetic resolution for southwestern Asian species than obtained in previous studies. A medium corolla length (15-18mm) was reconstructed as the ancestral state for Salvia with multiple shifts to shorter and longer corollas. Macroevolutionary model analyses indicate that corolla length disparity is high throughout Salvia evolution, significantly different from expectations under a Brownian motion model during the last 28 million years of evolution. Our analyses show evidence of a higher diversification rate of corolla length for some Andean species of Salvia compared to other members of the genus. Based on our tests of diversification models, we reject the hypothesis of a direct effect of the lever mechanism on Salvia diversification. Conclusions: Using a broader species sampling than previous studies, we obtained a well-resolved phylogeny for southwest Asian species of Salvia. Corolla length is an adaptive trait throughout the Salvia phylogeny with a higher rate of diversification in the South American clade. Our results suggest caution in considering the lever-mechanism pollination system as one of the main drivers of speciation in Salvia.

Rancang Bangun dan Uji Performansi Alat Pembuka Katup Menggunakan Mekanisme Tuas

<p><em>The increasing number of vehicles every year provides opportunities to vehicles service. Vehicle components that often serviced or overhaul is the valve mechanism. How to remove the valve from the cylinder head generally use a manual valve remove tool. The time required to remove the valve using the tools need a long time. Effort to overcome these problems is to modify the existing valve remove mechanism. The purpose of this research is to design and test the performance of valve remove using lever mechanism. Performance test was conducted to determine the press force value to remove the valve, the percentage increase performance and time to remove the valve. The main components of the valve remove tool using the lever mechanism is frame, table, pole support, locking, hand grips, hydraulic, lever pusher and shaft sled. Testing using the valve mechanism is contained in the cylinder head Toyota Kijang 4K. The valve remove tool design has a simple form, easy to make, cheap, but has very good performance. The smallest of the press force to remove the valve is 129 N obtained at a distance of lock and poles support as far as 22 cm. The valve remove tool using the lever mechanism was design can remove the valve from the cylinder head in time 26,17 seconds/valve or 418,67 seconds to remove 16 valves on the cylinder head. This tool is able to improve the performance of manual valve remove tool screw type by 76,28%, and can improve the performance valve remove tool the pneumatic system by 65,79%.</em></p>

Design of a Fast Temporary Fastener with the Labor-Saving and Reversible Ability

Aircraft panel assembly mainly includes the pre-joining process and the riveting process. In addition, the traditional pre-joining process is mainly executed by bolts, which has problems such as the large tightening torque, inconvenient bilateral tightening, heavy workload, and inconvenient loading and unloading. To solve the above-mentioned problems, a research of new temporary fastener is performed deeply from three levels of quick installation, labor-saving, and reversible ability. This involves (a) employing the lever mechanism and the rapid expansion anchor to implement the rapid clamping and disassembly of working processes by labor-saving; (b) integrating the adjusting spring to overcome the tolerances of parts; and (c) building up the space-cross slide rails to provide the axial clamping forces and the reversible forces. The application of designed fasteners was employed into the production of aircraft panel, and the error between theoretical and experimental values was less than 10%. Besides this, the result showed the good effect in panel clamping and the reliable processes of loading and unloading installation, and will greatly reduce the complexity of pre-joining process, the difficulty of installation, and the comprehensive cost.

Bioinspired Divide-and-Conquer Design Methodology for a Multifunctional Contour of a Curved Lever

In this study, we propose a bioinspired design methodology for a multifunctional lever based on the morphological principle of the lever mechanism in the Salvia pratensis flower. The proposed divide-and-conquer contour design methodology does not treat a lever contour as a single curve that satisfies multiple functions. Rather, the lever contour combines partial contours to achieve its assigned subfunction. This approach can simplify the complex multifunctional problem in lever design. We include a case study of a lever utilized in a compact variable gravity compensator (CVGC) to explain the methodology in more detail. In the case study, four partial contours were designed to satisfy three types of functional requirements. The final design for the lever contour was manufactured and verified with visual measurement experiments. The experimental result shows that each partial contour successfully achieved its subfunctions.

Minimum Distance Warning and Braking System for Vehicles

A vehicle distance measuring safety warning and braking system is disclosed having one or more distance measurement sensors measuring the distance from the driver's vehicle to a second vehicle immediately in front, the minimum distance between the vehicle and any object depends on the speed of the vehicle and here the speed of the vehicle is measured by calculating RPM(revolutions per minute) of wheels, based on the calculated minimum distance the speed of the vehicle is regulated by auto-lever mechanism. A vehicle distance alarm alerts the driver when the distance between the driver's vehicle and the second vehicle is less than a configured minimum distance, indicating an unsafe driving condition. An event record display device displays the time/date or the last twenty occurrences of the distance warning alarm. When an alarm is generated, a throttle set-back actuator operates to gently and automatically slow the car and increase vehicle to vehicle distance. Vehicle brakes may be automatically applied by the system to further slow the vehicle. The vehicle distance measuring safety warning system provides an additional margin of safety for a driver who may be distracted while driving.

Development of a 3-DOF Flexible Micro-Motion Platform Based on a New Compound Lever Amplification Mechanism

In this paper, a flexible micro-operation platform with three degrees of freedom, large stroke, and high precision is designed to meet the higher demands in the fields of biological engineering and medicine. The platform adopts a compound lever mechanism. The theoretical magnification of the mechanism is 9.627, the simulation magnification is 10.111, and the error is 5.02%. The platform uses a piezoelectric ceramic driver to increase the output stroke to obtain a larger movement space. The composite lever mechanism and new micro-operating platform are studied by theoretical calculation and finite element simulation. The results show that the new flexible micro-operating platform based on the composite lever mechanism has good motion decoupling and high precision.

Five-Fingered Passive Force Feedback Glove Using a Variable Ratio Lever Mechanism

Force feedback gloves allow users to touch and manipulate virtual objects intuitively. Compared with gloves providing active feedback force, gloves with passive feedback force are promising in terms of safety and low weight, but simulating the variable stiffness of virtual objects is more challenging. Addressing this difficulty, we propose a five-fingered glove with passive force feedback employing a variable ratio lever mechanism. The stiffness of the proposed glove is tuned by changing the structural stiffness of this mechanism rather than by applying torque control at each joint of the finger. The switch between free and constrained space is realized in real time by locking/unlocking the revolute joints of the glove using a servo motor. Furthermore, a predictive control mode is proposed to reduce the response time of the control system, and the actual response time is less than the limit of the delay (45 ms) that humans can perceive between visual and haptic stimuli. Experimental results show that the linear stiffness at the fingertip ranges from 0.89 to 619.89 N/m, and the maximum backdrive force of the proposed glove is less than 0.147 N.