Medium voltage vacuum circuit breaker with per phase electromagnetic actuator

In medium voltage vacuum circuit breakers, in order to achieve an even distribution of force along the entire length of the drive shaft, the drive mechanism is made per phase, that is, a separate electromagnet is installed under each pole. The analysis of designs and features of operation of vacuum circuit breakers with a per phase electromagnetic drive is carried out. Deficiencies in the designs of these drives have been identified. The design of a vacuum circuit breaker with a per phase electromagnetic drive and a kinematic diagram of the operation of a vacuum circuit breaker with a monostable polarized electromagnet and a return spring during the closing operation are considered. As a per phase drive, it is proposed to use three monostable polarized electromagnets with return springs, which makes it possible to reduce the overall dimensions of not only the drive electromagnet, but also the vacuum circuit breaker. Moreover, the return spring is not included in the design of the proposed electromagnet, but is part of the circuit breaker drive mechanism. The design of the housing of the vacuum circuit breaker with a per phase drive and a synchronizing shaft has been developed, which makes it impossible for the non-simultaneous closing and opening of the main contacts when performing switching operations. The calculation of a monostable polarized electromagnet is carried out and the possibility of its use as a per-phase drive in a medium voltage vacuum circuit breaker is confirmed.

Reliability Analysis of Accelerated Destructive Degradation Testing Data for Bi-Functional DC Motor Systems

An accelerated degradation test (ADT) has become a popular method to accelerate degradation mechanisms by stressing products beyond their normal use conditions. The components of an automobile are degraded over time or cycle due to their constant exposure to friction or wear. Sometimes, the performance degradation can be measured only by destructive inspection such as operating torques of return-springs in a bi-functional DC motor system. Plastic deformation of the return-spring causes the degradation of actuating forces for shield movement, resulting in deterioration of the shield moving speed in a headlight system. We suggest a step-by-step procedure for a reliability analysis for a bi-functional DC motor in a headlight system, based mainly on accelerated destructive degradation test (ADDT) data. We also propose nonlinear degradation models to describe the ADDT data of the return-springs. Exposure effects of high temperatures on the return-springs are quantitatively modeled through the ADDT models. We compare the estimation results from both the closed-form expression and Monte Carlo simulation to predict the failure–time distribution at normal use conditions, showing that the lifetime estimation results from the closed-form formulation are more conservative.

Design and Simulation of Electromagnetic Linear Actuators for Jet Dispensers

Three electromagnetic-based linear actuators, namely a solenoid actuator (SA), a moving coil actuator (MCA), and a moving magnet actuator (MMA), are proposed for driving the needle in a jet dispenser. The total resistance force acting on the needle during operation, including the damping force, the friction force, the inertia force, the compression spring force, and the backpressure, are measured by an experimental model. The thrust force required to overcome this resistance force is then predicted for each actuator using finite element analysis (FEA) simulations. Simple two-dimensional models of the SA, MCA, and MMA are constructed using the same coil dimensions in every case in order to facilitate an objective comparison between them. Simulations in ANSYS Maxwell software are then performed to adjust the specific dimensions of each actuator structure in such a way as to generate the thrust force required to drive the needle in the jet dispenser with the minimum excitation current possible. The simulation results show that for a maximum needle driving frequency of 250 Hz and a stroke length of 0.5 mm, the excitation current required to generate the necessary thrust force is equal to 1.8 A and 1.9 A for the MCA and MMA models, respectively, when a return spring is not used, and 2.2 A, 3.8 A, and 4.1 A for the SA, MCA, and MMA models, respectively, when a return spring is employed. It is additionally shown that the thrust force drop of the MCA and MMA models is far less than that of the SA model, about 0.7%, 1.8%, and 61% for three models, respectively. Three preliminary designs for jet dispensers incorporating the proposed actuators are also generated for reference purposes.

Analysis of small intermediate relays from leading manufacturers

This paper presents a comparative analysis of technical characteristics and designs of small intermediate relays from various manufacturers. The following main characteristics of relay are considered: operation and release values; weight and dimensions; power consumption; time parameters; reliability characteristics. The design of the relays of the Russian and international manufacturers are being discussed, their design features that affect the technical characteristics are considered. It is noted that the fastening of movable contacts directly to the armature (relays from Finder, Relpol, Irkutsk Relay Plant) requires a flexible connection with the relay contacts, which leads to more complicated assembly and calibration of relays. It is shown that the kinematic diagram in the presence of free travel with no mechanical coupling with the contact pusher, used in the relay from Schrack, can reduce power consumption and increase the vibration and shock resistance of the relay break contacts. In Schrack AC relays, the operating clearance zone is configured to create a short-circuited loop with reduced electrical resistance and to provide optimum conditions for reducing armature vibration. The appropriate relay designs in terms of improving technical characteristics are proposed. The advantage of a flat return spring over cylindrical coil springs in terms of manufacturing technology and stability of mechanical characteristics of relay is shown. It was revealed that the electromagnetic drive of the Schrack relay compares favorably with electromagnetic drives of other companies in terms of the use of stray magnetic fluxes to create a useful electromagnetic torque. Based on the results of the comparative analysis and experimental study of existing relay designs, recommendations were formulated for the development of a new series of the Russian small intermediate relays within the framework of the import substitution program.

The adaptive potential of sweet cherry varieties (C. avium L.) under the conditions of Southern horticulture

The results of research on the stability of sweet cherry varieties of different ecological and geographical origin to low-temperature stresses in the Southern horticulture are presented. The aim of the research was to comprehensively assess the generative potential of sweet cherry varieties after stress factors affect and identify the most resistant varieties to the stressors. It is shown that the probability of occurrence of abnormal frosts (limiting) in the range of –33.0°C or return spring frosts –4.0–5.0°C in the Prikuban gardening zone of the Krasnodar Territory is 40% on average. It was found that abnormal frosts can affect sweet cherry plants at the beginning of the dormant period – in december, more often in the middle – in February, less often at the beginning of the growing season – in march. The frequency of recurrent spring frosts affect during the blossoming period is high. The degree of ruin of the sweet cherry generative organs is determined by the type of stress, the limiting temperature and specificity of varieties. The obtained results confirmed that the sweet cherry varieties of local (domestic) breeding were more resistant to frosts and to early spring frosts. According to frost resistance, the sweet cherry varieties of Alaya, Volshebnitsa, Mak and Kavkazskaya are selected. According to the resistance to early spring frosts the varieties of Anons, Alaya, Volshebnitsa, Mak, Kavkazskaya, Sashenka, Demetra and the Dar Izobiliya are selected. According to the complex resistance to frost and to early spring frosts, the varieties of NCFSCHVW breeding of Alaya, Volshebnica, Mak and Kavkazskaya, are selected and recommended for creating the intensive, adaptive gardens in the South of Russia, and to a certain extent they will allow you to control the production potential of plantations of stone fruit crops in order to obtain the consistently high yield capacity of 20-25 t/ha.

The use of pneumatic cylinders with a return spring to compensate for balance losses in mechanical regenerative drives for reciprocating movements

Mechanical spring drives with energy recovery are designed to produce return-rotational movements in various technological equipment and reduce energy costs by several times compared with traditional electromechanical, hydraulic and pneumatic drives. The use of pneumatic motors in spring drives to compensate for dissipative losses, fixing the drive in extreme positions and the primary charging of spring batteries is considered. The class of tasks in which spring drives with energy recovery are created using only pneumatic cylinders with return springs is highlighted. This study examines mechanical spring drives with energy recovery, based on nonlinear spring batteries with spring preload in the middle position of the output link. The use of pneumatic actuators with return springs in mechanical drives based on linear spring batteries with two springs is proposed. Mechanical spring drives with energy recovery are designed to produce return-rotational movements in various technological equipment and reduce energy costs by several times compared with traditional electromechanical, hydraulic and pneumatic drives. The amount of energy expended in spring recuperative drives is actually determined by the energy expended on compensating for dissipative losses in kinematic pairs. The results of the study allow the designers of such drives to consciously approach the choice of their schemes and design parameters.

Моделирование работы циклического привода на основе изгибного силового элемента, выполненного из материала с эффектом памяти формы

We consider a linear cyclic unilateral actuator based on a force element made of a material with the shape memory (SM) effect and a return spring. We have developed a model of such an actuator, which makes it possible to connect its characteristics with functional properties of the SM material. The model makes it possible to perform engineering design of the main characteristics of the cyclic actuator.

Design and Hybrid Impedance Control of a Powered Rowing Machine

A conventional rowing machine was modified with an electric motor and a robust impedance control system to mimic the behavior of a conventional rower and subsequently expand its versatility. The powered machine has programmable impedance and can produce controlled forces during the return stroke, allowing for eccentric exercise. Conventional rowers do not allow eccentric loading, an exercise modality known to contribute significantly to the efficacy of training. Eccentric loading is particularly important to diminish the detrimental effects of humans operating in microgravity for long periods of time. Conventional rowers include a flywheel, a fan and a freewheeling clutch. These elements were removed and replaced by a torque-controlled motor and a belt transmission selected on the basis of the forces and velocities encountered in the rowing exercise. A hybrid dynamic model was developed for the conventional rowing machine to account for its force-velocity characteristics and the transitions between the coupled (pull stroke) and the decoupled (return stroke) of the freewheeling clutch. Machine parameters such as flywheel inertia, air damping coefficients and return spring constants were identified from a set of experimental data and fitted to the model. The model was then used to design the robust hybrid impedance controller which includes a virtual flywheel and a force sensor to determine the transitions between pull and return strokes. The controller reproduces the operation of the original machine and can also be programmed to produce arbitrary impedances. The paper describes the hybrid dynamic model and control approach and the real-time experimental trials.

DISAIN SISTEM KONTROL MESIN AUTO WASHER FEEDER BERBASIS KENDALI PLC UNTUK PERAKITAN BVC (BASE VALVE COMPLETE) PADA PEMBUATAN SHOCK ABSORBER

Line sub assembly merupakan line di mana komponen bagian dalam dari shock absorber dirakit. Salah satu proses pada line sub assembly adalah proses perakitan Base Valve Complete (BVC). BVC merupakan salah satu komponen penting pada shock absorber yang berfungsi mengatur sirkulasi fluida pada saat shock absorber mengalami kompresi. BVC untuk model shock absorber ini terdiri dari guide, non-return spring, non-return valve, base valve case, leaf valve, shim, dan valve stopper. Leaf valve merupakan plat tipis berbentuk lingkaran dengan ketebalan 0.1-0.2 mm. Permasalahan pada proses perakitan BVC adalah operator kesulitan dalam memisahkan leaf valve sesuai dengan jumlah yang ditentukan. Kesalahan jumlah leaf valve yang dirakit akan menyebabkan BVC menjadi reject. Solusi dari permasalahan tersebut adalah dengan dibuat mesin auto washer feeder. Mesin ini berfungsi untuk mengeluarkan leaf valve sesuai dengan jumlah yang ditentukan. Kontrol pada mesin auto washer feeder terdiri dari perangkat input, perangkat proses, dan perangkat output. Perangkat input terdiri dari push button, selector switch, toogle switch, emergency switch, photoelectric sensor, proximity sensor, reed switch. Perangkat proses menggunakan PLC Omron CJ1M-CPU11. Perangkat output yang digunakan adalah lampu indikator, silinder pneumatik, dan cool muscle ac servo motor. Hasil yang diperoleh dari pembuatan mesin ini adalah operator menjadi lebih mudah dalam melakukan perakitan leaf valve, berkurangnya waktu perakitan leaf valve dari 81 detik menjadi 50.6 detik, dan berkurangnya jumlah BVC yang reject dari 8 pcs per minggu menjadi 0 pcs per minggu.

Design of a highly efficient friction clutch apparatus for vehicle applications using a self-energizing mechanism

This study proposes a new design for a friction clutch actuator using the self-energizing principle for vehicle applications such that the power consumption for clutch control is significantly reduced. The self-energizing effect can be created by simply adding wedge structures to a conventional clutch system, and it assists in significantly reducing the actuation energy of the clutch with little additional cost. In this paper, a mathematical model of the clutch actuation system is derived on the basis of static force analyses with particular emphasis on the torque amplification factor due to the self-energizing effect. The slope angles of the wedges in the proposed clutch actuator are determined in order that the clutch system ensures appropriate torque amplification while considering various factors such as the variations in the friction coefficient and the return spring force. In addition, model-based analyses of the new clutch actuator system are performed in order to predict the dynamic effects of the self-energizing mechanism on the system, particularly for the clutch engagement process. The feasibility of the proposed clutch design and its high energy efficiency are verified experimentally using three prototypes with different slope angles.