HYDRAULIC MACHINES FOR SEPARATION OF WET DISPERSED SYSTEMS

Separation processes of wet dispersed systems are quite common in the food, processing and other industries. In particular, these include processes related to the production of fruit and vegetable juices, jams, sunflower and olive oil, the extraction of fat from meat rinds in meat production, the separation of whey from cheese mass in the production of cheese, the separation of grated cocoa into butter and pulp, dehydration of wet dispersed waste of food production (alcohol grain, beer pellets, beet pulp, coffee and barley sludge). These processes are quite energy-intensive and have low-productivity, therefore, much attention is paid for modernization of equipment for their implementation in the direction of improving the indicated efficiency characteristics, as well as increasing reliability and reducing material consumption, complexity and price of working machines. At the same time, the known hydraulic static presses do not provide of low final moisture content of the product and the required productivity of the working process. Vibratory pressing equipment is often quite complex, unreliable and generates intense noise and vibration during of operation. Screw presses with an electromechanical drive, despite of their advantages, do not allow to achieve of the necessary degree of separation of the components of the dispersed system, in addition, their actuators are structurally quite complex and wear out quickly. The authors propose improved schemes of hydraulic presses for separation of wet dispersed systems, which can provide high rates of efficiency of the working process and have a simple and reliable design. The article also presents equations for calculating of the main operating parameters of the proposed equipment.

MODELING OF MECHANICAL TRANSMISSION TAKING INTO ACCOUNT FREQUENCY OF TOOTH-ENGAGEMENT

At present time, in control systems, an electromechanical drive, which includes a reduction gear, is widely used. To ensure the quality of the output movement of the drive, it is not enough synthesize it according to the criteria of performance and accuracy. With increasing requirements for drives, the need arose for such an indicator of the quality of dynamics as smoothness [1], which is mainly influenced by the quality of the mechanical transmission production. The article provides an example of modeling a reduction gear taking into account multi-massage, the number of teeth, geometric errors of tooth-engagement, imbalance of the engine rotor. The spectrum of speed fluctuations of the output link is obtained, which characterizes the smoothness of the reduction gear operation. A conclusion is made about the prospect of using a model approach to diagnose the smooth operation of reduction gears.

Electromechanical drive of sliding doors with mechanical energy accumulator

The design of an electromechanical drive for sliding doors with a mechanical energy accumulator is proposed, which excludes the withdrawal of doors from extreme positions using an electric motor. Analytical expressions for the kinetostatic parameters of the device are obtained. The method of choosing the accumulator spring is presented. Keywords: sliding door, drive, reliability, energy, accumulator. [email protected], [email protected]

DESIGNING A MIXER OF PROTEIN, MINERAL AND VITAMIN ADDITIVES

To ensure the eff ective use of protein-mineral-vitamin supplements in the diets of dairy cows, a mixer design has been developed for their preliminary mixing before adding to the main mixing process. Based on the structural-morphological analysis, alternative structural elements of the mixer design have been considered and conventional symbols were assigned to them. A morphological matrix of solutions has been compiled to off er a set of alternative options. The mixer drive was chosen by the ability to ensure high speed, rotational speed control, user-friendly operation and cost. The design uses an electromechanical drive combined with a V-belt drive. This solution meets all the specifi ed requirements and allows protecting the drive from possible overloads. The working tool was chosen based on the requirement to contact the material actively throughout the chamber volume and to avoid the formation of stagnant zones. A blade mixer with variable blade positioning was found the most eff ective tool for the high-speed mixing of bulk materials. The designed mixer will be operating at a continuously varying speed in the range from 500 to 1500 min-1. This will off er the advantages of high-speed mixing while reducing the infl uence of negative factors on the fi nal mixture quality. The resulting decision matrix will allow determining the most promising areas for further designing, which makes it possible to improve the quality of the developed technical means.

On Developing an Electromechanical Drive Equipped with a Ball Screw Protected from Jamming

At present, one of the most pressing issues is the problem of improving electromechanical drive reliability, specifically, eliminating the possibility of jamming in the ball screw. The paper proposes an engineering solution designed to replace expensive imported ball screws. We analysed alternative designs intended to improve electromechanical drive reliability. We proposed and patented a ball screw design featuring a separator, in which the nut acts as a piston. The structure consists of a smooth cylindrical body and a slotted separator, its slots positioned along a helical line with a step equal to the thread lead. The body and the separator are coaxial and rigidly fixed together at the separator end faces so that the rolling elements remain in contact with the screw thread surfaces, the internal smooth cylindrical surface of the nut body and the surfaces of the separator slots. The ball screw design proposed, which features a nut with no internal threading, significantly simplifies the structure and its manufacturing technology. We built a model of an electromechanical drive equipped with a recirculating ball screw in order to determine static and dynamic properties of an electromechanical drive containing a ball screw featuring a separator. We compared the strength of the ball screw designs considered. As the ball screw featuring a separator is simpler and more reliable, the results of our analysis and the properties of an electromechanical drive equipped with the design proposed show that it is a promising solution to the import substitution problem concerning recirculating ball screws