Indexing rotary mechanism is widely used in automatic machines. There are studies of such mechanism kinematics showing its effectiveness. The undertaken strength studies demonstrate the ability of the mechanism to operate under specified loads. Actual tests performed on prototypes exposed inoperativeness of the spherical bearing, namely jamming, under the load. The current work analyzes the failure of the spherical bearing. Factors affecting the jamming are determined as well. Such factors are forces at engagement and the friction forces at spherical surfaces contact. Structural provisions are proposed and considered to solve the issue of jamming and provide the mechanism normal operation.
The article is devoted to the actual problem of starting an automobile engine in conditions of low negative temperatures. To increase the likelihood of starting the engine when using autonomous means of pre-heating, it is necessary to optimally distribute the battery energy to the pre-start and start-up discharges. As a part of the creation of a system, an automated pre-start thermal preparation of an automobile engine the need arises to conduct research on the influence of the battery starting-up discharges on the parameters characterizing the functioning of the electric starter system.
Research methods. A mathematical model of the electric starter system for starting the internal combustion engine is presented. The model is implemented using the software Mathcad 15.
Results. As a result of the simulation of the start-up system, the dependencies of the crankshaft rotation speed on time have been obtained for various values of battery discharge and temperature. According to the frequency of rotation of the crankshaft and the coefficient of dynamism of the battery discharge and the temperature of the electrolyte are also derived.
Findings. As a result of analyzing the data obtained in mathematical modelling it was determined that with decreasing electrolyte temperature the effect of the pre-discharge of the battery on the rotational speed of the crankshaft increases significantly. The ratio of the maximum rotational speed to the rotational speed of the crankshaft at the end of the start-up is almost independent of the degree of the battery discharge.
The article describes a system for setting and stabilizing the radiation frequency of submersible downhole vibrators. It is assumed that submersible downhole vibrators are used for vibration wave impact on the bottomhole formation zone in wells with a depth of 50 to 300 meters, in which the bottomhole part is structurally designed to be able to convert a comprehensive (pulsating) impact into an oscillating one. In this case downhole vibrators must be subject to additional requirements for the frequency range of the radiation and the accuracy of maintaining the frequency. The speed of rotation and the frequency of the rotary hydraulic vibrator, which is installed in the bottomhole, depends on the fluid flow through the vibrator. In the operation of a submersible vibrator as a hydraulic machine, it must be taken into account that the working fluid from the pump to the vibrator is supplied through a system of oil well tubing, which is a long hydraulic line. The authors of the article compiled a block diagram of the control system, taking into account the transfer functions of the flow controller, a long hydraulic line and the vibrator. The text gives valuable information on the possibility of using flow controllers to ensure setting and stabilization of the radiation frequency of the vibrator.
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