Purpose and device of hydraulic drive.hydraulic drive “, a system of interrelated mechanisms is designated to create fluid pressure and transfer it to the piston of a working cylinder. Hydraulic drives are widely used in grinding, broaching, longitudinal and other types of metal cutting machines for making feed motion Cutting tools The advantages of ri1drive drives include: a) the possibility of uninterrupted feeding; 6) ease of smoothness of reversal of motion; c) self-lubricating system, because mineral oil is used as the working fluid; r) automatic overload protection; e) High cost of equipment. The disadvantages are: the possibility of oil leakage through leaks in the connections and the difficulty of detecting the intimidation of malfunctions. There are different types of hydraulic drive for the reciprocating and for the rotator oro movement. The hydraulic drive for reciprocating motion consists of an oil reservoir, an oil pipeline system, a pump with a safety valve, a dispenser and a working cylinder (the piston rod of which informs the reciprocating motion of the associated parts of the machine). In the hydraulic drive for rotary motion there are two pumps, one of which creates pressure in the rinp ° system, is a hydraulic motor with a rotational movement of the second Naf lir. 85, a is a diagram of the hydraulic drive for reciprocating motion. The machine table 1 receives a reciprocating motion through the rod 3 of the piston 13 moving to the right, if the oil and pressure is supplied to the left side of the working cylinder 14, and, in contrast,
197 When the piston moves to the right, the waste oil from the right side of the working cylinder through the oil line !! 5 and 6 goes into the oil reservoir 7 “The oil pressure in the hydraulic system creates the pump 10 and feeds it into the working cylinder through the slide valve 12. When the machine table comes to the extreme right and the left stop with the lever 4 moves the spool – to the right the oil through the ring groove of the spool and the oil pipe 5 will start to flow into the right side of the working cylinder (the piston will go to the left), etc. The stops on the machine table can be rearranged and still change the length of the table’s stroke. and the quantity of oil supplied to the hydraulic system, and the ball valve 11 serves to protect against overloads. In hydraulic actuators, several types of pumps are used, differing in the principle of operation, namely gears, locks and pistons .The first two types are most common because of their compactness , simplicity of the device and reliability in operation Figures 85, 6 and 8 show schematic diagrams of gear and vane pumps. The pump consists of a cast iron body 1 (Figure 85.6) and two wide cylindrical gears 2, one of which is the driving one. By rotating the gears (in the direction of the arrows in the diagram), the oil from the left side of the pump is transported to the right side of the pump, and from there through the oil pipe to the switch gear. Gear pumps create a pressure in the hydraulic system of 10-12 at. the lobe pump is also mounted in a cast iron body and its main part is a rotor 4 fixed to a key on the shaft 2, the rotor has blades 3 which are pressed against the inner surface of the steel ring 5 by the springs / springs. When the rotor rotates at the speed delivered by the stator. 1000 rpm in, the oil line is fed up to 100 liters of oil per minute, the overflow and throttle valves serve to regulate the hydraulic system of the pressure and the amount of oil supplied to the fuses. The safety valves are designed to automatically reduce the hydraulic oil pressure when the limit is exceeded. Fig. 85, 2110 shows the designs of the throttle valve and the ball valve. When the hydraulic system is overloaded, the oil pressure overcomes the spring force of 1; the bulb 2 rises and the excess oil passes through the duct 3 into the reservoir. The spools are distributing devices and provide the supply of oil under pressure alternately in the right and left cavities of the cylinder, and also the return of the used oil back to the reservoir. The most common are cylindrical 30 trays (see Figure 85, e). At the position of the spool 1 on the right is oil.
The pressure flows through the channels 3 and 2 into the left cavity of the working neck, and the used oil flows through the channel 4 into the reservoir. When moving the oil, it moves through the channels 3 and 4 to the right side of the cylinder, and through the second valve, the spent oil of the spool goes to the leftmost position of the cylinder.