A promising direction in developing up-to-date transport vehicles is the use of transmissions, an essential element of which is a dual-clutch. Improving functional performance, energy efficiency, and environmental friendliness are relevant and require appropriate research. The object of study is a dry dual-clutch working with a manual transmission with high energy efficiency. In the proposed design scheme, a rotary lever and a movable carriage can change the structural diagram of the force interaction between the pressure spring and the clutch discs. The developed mathematical model of the clutches control mechanism allowed for analyzing the process of controlling the dual-clutch transmissions (DCT) and obtaining functional dependencies between pushing forces in friction pairs and the carriage position. As a result, a method for synthesizing DCT was proposed to ensure the transmission of a given torque. Furthermore, it was determined and numerically proven that the same radial movement of the carriage when switching-on the clutches does not guarantee equal loading for the frictional discs of each clutch. This fact increases the uneven dynamics of torque and disc wear. Overall, the synthesis of the energy-saving dry dual-clutch control mechanism providing the same clutch margin for each clutch was developed. The method can be generalized and applied to designing dry dual-clutch transmissions for machines of various purposes.
Titanium alloys are widely used in military equipment because of theirs excellent physical properties, such as corrosion resistance, heat resistance, fatigue resistance, and high specific strength. However, the hardness and strength of titanium alloy are high, and the coefficient of thermal conductivity is poor, so the cutting performance is poor. The influence of solid lubricant on the parameters of the process of diamond grinding of hard-to-cut material – titanium alloy VT22 was studied. The evaluation was carried out on the basis of the surface roughness parameter Ra and the postcontact temperature Tpc. It has been established that the use of a solid lubricant based on stearic acid (65%) and molybdenum disulfide (35%) reduces the post-contact temperature by 1.4 ... 2.1 times and the roughness by 1.3 ... 1, 6 times in comprising with results under dry grinding conditions. Solid lubricant has an ambiguous effect on the grinding performance of VT22 depending on transverse feed. It may be linked up to state transition of stearic acid and growth its surface activity. The best results on the surface quality with solid lubrication were achieved under grinding with cutting speed Vc = 25 m/s and transverse feed f = 0.005 mm/double pass.
Extending the durability of functioning of the sensitive elements of radiation indicators and increasing their reliability and safety are the main requirements for producers of modern radiation reconnaissance and monitoring devices. The proposed solutions for construction improving of products provide for the usage of optical fibers and the corresponding formation of loop-shaped channels in the finished sensitive polymer element. Potential possibilities of using magnetic abrasive polishing for finishing channel surfaces are considered. For the chosen construction of the polishing head, the material and form of the powder particles composition and the process parameters are proposed. The effect of the frequency and amplitude of vibration of abrasive particles on the depth of their penetration into the surface layer of the polymer is investigated. It has been determined that the widest possibilities of using powders of the composition Fe - C - Si - Ti with a diameter of d = 50 – 400 μm have a mode when the pressure of the air flow by feeding particles is maintained at a level of 1 atm, the magnetic induction of the field in the working gap is 0.8 T, the vibration amplitude of the particles is a = 0.4 mm, and the vibration frequency varies in the range f = 25 – 30 Hz.
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