RU1770648C - Variable-delivery pumping unit - Google Patents

Abstract

Usage: in hydraulic automation The essence of the invention: the control mechanism 2 of the variable pump is made in the form of a hydraulic motor 17 and a distributor 18 connected to it. The hydraulic lines 6 of the make-up pump 5 are connected through check valves 7, 8 with connecting hydraulic lines 3, 4 and through the flow element with the outputs of the safety valves 13, 14. The flow element is made in the form of a throttle device. The feedback device 10 is made in the form of an auxiliary hydraulic motor with two drive cavities 23, 24 kinematically connected to the distributor of mechanism 2. The throttle device is made in the form of two retaining chokes 15, 16 connected by inputs to the cavities 23, 24 and connected by exits with a hydraulic line 6. Throttle device m. made in the form of one retaining throttle 3 z.p.f-ly, 5 ill.

Description

Figure 1

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The invention relates to the field of hydraulic automation and can be used in hydraulic drives of hoisting-and-transporting units.

The aim of the invention is to increase efficiency by reducing the power consumed by the make-up pump.

Figure 1 shows a hydraulic circuit of an adjustable pump unit; Fig. 2 is a diagram with a feedback device in the form of an auxiliary hydraulic motor; Fig. 3 is a diagram with safety valves connected by outputs to each other; Fig. 4 is a diagram with a feedback device in the form of a two-line distributor; Fig. 5 is a diagram of a four-line feedback distributor.

The adjustable pump unit (Fig. 1) contains an adjustable pump 1 with a control mechanism 2, connecting hydraulic lines 3 and 4 connected to a consumer (not shown), a charging pump 5 with a charging line 6 connected through check valves 7 and 8 with a hydraulic line 3 and 4, and a feedback block 9 for overpressure in the connecting hydraulic lines 3 and 4 of an acceptable value, comprising a feedback device 10 and feedback sensors 11 and 12, made in the form of safety valves 13 and 14, the inputs of which associated with hydraulic lines 3 and 4, and Exit - with the device 10 and inputs retaining throttles 15 and 16, the outputs of which are associated with the hydraulic line 6

When executing the mechanism 2 (Fig. 2) in the form of a hydraulic motor 17 and a control distributor 18 connected thereto, hydraulically connected by hydraulic lines 19 and

20, and kinematically - lever system

21, the system 21 being provided with an additional input 22, and the feedback device 10 is made in the form of an auxiliary hydraulic motor with two drive cavities 23 and 24 kinematically connected with the input 22 of the system 21.

When performing the device 10 (Fig.Z) with one drive cavity (not indicated), the valves 13 and 14 are connected by outputs to each other and to the input of a common retaining throttle 25.

When executing the mechanism 2 (Fig. 4) in the form of a hydraulic motor 17 and a distributor 18 connected by hydraulic lines 19 and 20, the device 10 is made in the form of a two-position, two-line, two-line spring-loaded hydraulically controlled distributor 26, connected in parallel to two inputs to the distributor 18 the cavity of which is associated with the outputs of the valves 13 and 14 connected

between themselves. The distributor 27 is made two-linear, with a position for separating the cavities (not indicated) of the hydraulic motor 17 and with a position for connecting the cavities of the hydraulic motor 17 to each other.

The distributor 26 (Fig. 5) can also be made four-linear with inlet hydraulic lines connected to the hydraulic motor 17 and with the output hydraulic lines,

0 associated with the drain and with each other, and has a position of separating the cavities of the hydraulic motor 17 from each other and from the drain, and the position of the connection of the cavities of the hydraulic motor 17 with the drain.

5 Adjustable pump unit (figure 1, 2) works as follows.

If the pressure in none of the connecting hydraulic lines 3, 4 does not exceed the maximum permissible value, the valves 13 and 14 of the feedback sensors 11 and 12 are closed, the flow through the valves 13 and 14 is absent at the inputs of the feedback device 10, and there is no mechanism 2 the control maintains the set feed

5 adjustable pump 1.

When the pressure in one of the connecting hydraulic lines, for example, 3 exceeds the permissible value, the safety valve 13 of the feedback sensor 11 opens, bypasses part of the pump 1 supply from the hydraulic line 3 to the input of the feedback device 10 and through the throttle 15 to the make-up hydraulic line 6 where does this part of pump 1 feed from check valve 8 come from?

5 enters the hydraulic line 4, returning to the circuit formed by the pump 1, the hydraulic lines 3 and 4 and the consumer of the pump 1, the valve 14 is closed and the signal at the second input of the device 10 is absent.

0 The feedback device 10, made in the form of an auxiliary hydraulic motor, is under differential pressure, since the pressure in front of the throttle 16 is equal to the pressure in the hydraulic line 6

5 recharge due to the lack of flow through the throttle 16, and the pressure in front of the throttle 15 is higher than the pressure in the hydraulic line 6. The pressure difference between the cavities 23 and 24 moves the latter, and with them through the additional input 22 of the lever system 21 of the distributor 18 to the position, of which the water supply lines 6 are connected to the hydraulic line 19 and the hydraulic line 20 to the drain, as a result of which a pressure differential is created between the cavities of the hydraulic engine 5 of the cylinder 17, which moves the hydraulic motor 17 in the direction of decreasing the supply of pump 1 to the hydraulic line 3. The supply of pump 1 to the hydraulic line 3 is smart It increases and the pressure increase in the hydraulic line 3 slows down until it stops.

In the implementation of the feedback device 10 with a single input (cig. 3, 4), the adjustable mounted unit operates as follows.

If the pressure in none of the connected hydraulic lines 3 and 4 does not exceed the permissible value, the valves 13 and 14 are closed, there are no flows through them, there is no signal at the input of the device 10, and the control mechanism 2 maintains the given supply of the pump 1.

When the pressure in one of the connecting hydraulic lines, for example, 3 exceeds the permissible value, the safety valve 13 opens, which transfers part of the pump 1 supply from the hydraulic line 3 to the input of the device 10 and through the throttle 25 to the make-up hydraulic line 6, from where this part of the pump supply 1 through the check valve 8 enters the hydraulic line 4.

At the inlet of the throttle 25 and in the drive cavity of the distributor 26 forming the feedback device 10, the pressure increases, which, having overcome the spring force, moves the distributor 26. When the distributor 26 is made two-linear, it moves from the position at which both cavities of the hydraulic motor 17 are separated from each other, to a position in which these cavities are interconnected. Between the cavities of the hydraulic motor 17, overflow occurs and the pressure drop is kept, which keeps the hydraulic motor 17 in the position corresponding to the predetermined flow of the pump 1. As a result, the hydraulic motor 17 moves in the direction of lowering the flow of the pump 16 in the hydraulic line 3, in which the pressure growth stops.

If the distributor 26 is made four-linear, with increasing pressure in its drive cavity, it connects the cavities of the hydraulic motor 17 with a drain, as a result of which the difference between the cavities of the hydraulic motor 17 is also reduced.

Claims (3)

1. An adjustable pump unit containing an adjustable pump with a control mechanism in the form of a hydraulic motor and a distributor connected to it, connecting hydraulic lines with safety valves, a charging pump with a charging water line connected through check valves to connecting hydraulic lines and through a flow element with safety valve outputs connected to at least one drive cavity of the feedback device, characterized in that, in order to increase efficiency by reducing power, otrebl emoy feeding pump, the flow element is formed as a throttling device. 2. The assembly according to claim 1, characterized in that the feedback device is made in the form of an auxiliary hydraulic motor with two drive cavities, kinematically connected to the control mechanism distributor, and the throttle device is in the form of two retaining chokes connected by inputs to the drive cavities m auxiliary hydraulic engine and connected to the outlets with a feed water line. 3. The unit according to claim 1, characterized in that the throttle device is made in the form of a retaining throttle 4. The unit according to claim 3, characterized in that the feedback device is made in the form of a hydraulic control valve, an four-line valve, the control cavity of which is connected to the entrance of the retaining throttle, the input hydraulic lines to the hydraulic motor of the control mechanism, and the output hydraulic lines are connected to each other and to the drain. FIG. 7 8 -f- J. - / -4- - 4H L-- -f - - / - / - - / - X / TjtLJJj ZSjMj Fig.Z id 20/9 // / 5 b 7 i J J / g. B /