SU1280194A1 - Axial-piston pump - Google Patents

Abstract

The invention relates to the field of hydraulic engineering and allows to increase the cost-effectiveness, as well as to expand the functionality by providing dual-mode operation of the cut-off unit (BO). BO 4 contains hydraulic spring-loaded valves (GPR) 21 and 22. Hydraulic control cavity 29 and GPR 21 inlet are connected to the discharge channel by lines 31 and 32, and the output is connected to cavity 34 of a stepped servo piston 14 by line 35. Additional hydraulic control cavity of the GPR 21 is connected to the channel pumping through GPR 22. The hydraulic control cavity 36 GPR 22 is connected to the control unit. As a result, it is possible, while maintaining the predetermined pressure, to substantially reduce the flow of the pump and, thus, the proportion of flow that is unproductively discharged through the safety valve. 1 hp f-ly, 4 ill.

Description

t1

The invention relates to hydraulic machine building and can be used in hydraulic actuators.

The purpose of the invention is to increase efficiency,

FIG. 1 shows schematically a pump, a general view of FIG. 1 in FIG. 2 - the same scheme; in fig. 3 .- feed change mechanism; in fig. D - cutoff block, cut.

The axial piston pump contains a rotary cradle 1 with a block of 2 cylinders, a mechanism 3 for changing the feed and a block 4. of a cut. The feed change mechanism 3 comprises a power limiter 5, a cylinder 6 with a piston 7, a zero-set compression spring 8, an executive cylinder 9 with a piston 10 having an axial bore in which the sleeve 11 is fitted, and a spool 12 placed in the sleeve 11.

The power limiter 5, in turn, includes a sleeve of the cylinder 13 with a stepped servo piston 14, interacting with a hard 15 non-receiving spring 16 and 17 of the compression. The spool 12 is rigidly connected with the thrust 15, and the piston 7 is mounted coaxially with the possibility of movement relative to it. On the piston 10 of the feed change mechanism 3, a fork 195 cooperating with the pump housing pin 20 is secured with a finger 18.

The cut-off block 4 contains two-position spring-loaded hydraulically controlled valves 21 and 22. The input of the spool 12 and the cavity 23 of the actuating cylinder 9 is connected by a line 24 to the source of the power control

th pressure P

forces Spool outlet

12 is connected to the cavity 25 of the actuating cylinder 9 by a line 26.

Remote control pressure

nor r

STORK

FROM control unit (not

shown) through line 27 is supplied to cavity 28 of 1 cylinder 6. Control cavity 29 of distributor 21 and its input, as well as cavity 30 of power limiter 5 are connected to a pump discharge channel (not shown), respectively, lines 31, 32 and 33. the distributor 21 is connected to the cavity 34 of the power limiter 5 by the line 35. The control cavity 36 of the distributor 22 is connected to the additional line 37 of the remote control of the control unit

15

2801

five

 ABOUT

, 35

20

25

thirty

45

-5-5

941

The inlet of the distributor 22 is connected by lines 31 and 38 to the discharge channel of the pump, and the outlet is distributed by line 39 with cavity 40 (el 21.

The device works as follows.

When starting an axial piston pump5 when DABL (5e remote control Rdisg O, 8

and P jnp. piston 7;

15, spool 12, piston 10, pin 18 and fork 19 interacting with the pin 20 of the swivel head are in the leftmost position (according to the drawing), which corresponds to the minimum feed rate. As the remote control pressure Pd increases, J..p the piston 7 moves to the right, compresses the springs 8, 16 and 17, moves to the right th 15 and the spool J2. cavity 25 and creates a force that moves the piston 10, the finger 18, the plug 19 to the right by the amount of movement of the spool 12, increasing the angle of inclination of the cylinder block of the pump, its volume constant and flow.

When the estimated pump power is exceeded, the servo piston 14, under the influence of the pressure of the fluid in the discharge channel supplied to the cavity 30 through lines 31 and 33, moves to the left, compressing the springs 16 and 17 and moving left 15 and the spool 12, as a result whereby the flow P enters only the cavity 23 of the actuator: cylinder 9. The piston 10, pin 18 and fork 19 move to the left, reducing the pump flow until the displacement force of the service 14 of the power limiter 5 is equal to that of the springs 16 and 17. Output parameters of the hydraulic pump (production the pressure P to feed (Q) becomes equal to the calculated N P Q const.

When the value of the injection pressure supplied through line 31 to the cavity 29 of the distributor 21 of the cut-off unit exceeds the calculated value by which the adjustable :: spring is adjustable, its pusher moves to the left, opening the way for the liquid under injection pressure to line 35 and then to the cavity 34 limiter 5 power. Area of 34 rascoli3

so that the force acting on the servo piston 14 becomes large enough to move it to the left all the way and move the thrust 15, the spool 12, the piston 10 to the given left position, which provides the specified minimum flow. Regulation takes place volumetricly, without losses on the safety valve.

When the pressure in the discharge channel decreases, the distributor 21 returns to its original position, the line 35 unloads and the force of the springs 16 and 17 moves the servo piston 14 and the piston 10 to the right gradually as the pressure in the line 35 drops. This ensures a smooth return of the swivel cage 1 with the 2nd cylinder to preset tilt angle (preset flow rate), if the remote control pressure remains the same as before the shut-off unit has triggered.

If it is necessary to operate the block 4 cutoffs in the second mode (lower value of the discharge pressure), include an additional source of remote control,. Fluid on line 37 feeds into p, the cavity 36 of the distributor 22 and moves it to the left, connecting the discharge channel to line 39 and then to the cavity 40 of the distributor 21. The pusher of the distributor 21 is under the action of pressure in two cavities - 29 and 40, and therefore, it operates at a lower injection pressure.

The invention allows, in accordance with the conditions of operation, while maintaining a predetermined pressure, to reduce the flow of an axial-piston pump and, consequently, the proportion of flow, which is unproductively discharged through a safety valve.

944

Claims (2)

r-u. Y and 30 "31 t. The invention relates to hydraulic engineering and can be used in hydraulic drives. The purpose of the invention is to increase the economy. FIG. 1 shows schematically a pump, a general view of FIG. 1 in FIG. 2 - the same scheme; in fig. 3 .- feed change mechanism; in fig. D - cutoff block, cut. The axial piston pump contains a rotary cradle 1 with a block of 2 cylinders, a mechanism 3 for changing the feed and a block 4. of a cut. The mechanism 3 and the feed change contains a power limiter 5, a cylinder 6 with a piston 7, a zero-set compression spring 8, an actuating cylinder 9 with a piston 10 having an axial bore in which the sleeve 11 is installed, and the sleeve 12 placed in the sleeve 11. The power limiter 5, in turn, includes a cylinder bushing 13 with a stepped servo piston 14, interacting with a hard non-admissible spring 16 and 17 of compression. The spool 12 is rigidly connected with a thrust of 15 and the piston 7 is mounted coaxially with the possibility of movement relative to it. On the piston 10 of the feed change mechanism 3, the plug 195, which interacts with the pump housing pin 20, is fixed with a finger 18. The cut-off block 4 contains two-position spring-loaded hydraulically controlled valves 21 and 22. The spool input 12 and the cavity 23 of the actuating cylinder 9 are connected by a line 24 to a source power steering. The output of the pressure spool P 12 is connected to the cavity 25 of the executive cylinder 9 by line 26. The pressure of the remote control of the control unit (not shown) is fed through line 27 to the cavity 28 of 1 cylinder 6. The cavity 29 of the control of the distributor 21 and its input, as well as the cavity 30 will limit the power l 5 to the pump discharge channel (not shown), respectively, by lines 31, 32 and 33. You run the distributor 21 connected to the cavity 34 of the power limiter 5 by the line 35. The control cavity 36 of the distributor 22 is connected to optional line 37 remote control control unit 41 The distributor 22 input is connected by lines 31 and 38 to the pump discharge channel, and distributes the output line 39 with cavity 40 (el 21. The device works as follows. When starting the axial-piston pump 5 when DABL This method is valid for 8T, for example, and for Pjnp. piston 7; t is 15, spool 12, piston 10, pin 18 and fork 19 interacting with pin 20 of the swivel head are in the leftmost position (according to the drawing), which corresponds to feed is minimal. As the remote control pressure Pd increases, J..p the piston 7 moves to the right, compresses the springs 8, 16 and 17, moves to the right th 15 and the spool J2. The flow P through the spool 12 enters from the rod end 23 of the actuating cylinder 9 into cavity 25 and creates a force that moves the piston 10, the finger 18, the plug 19 to the right by the amount of movement of the spool 12, increasing the angle of inclination of the cylinder block of the pump, its volume constant and flow. When the estimated pump power is exceeded, the servo piston 14, under the influence of the pressure of the fluid in the discharge channel supplied to the cavity 30 through lines 31 and 33, moves to the left, compressing the springs 16 and 17 and moving left 15 and the spool 12, resulting in a flow P enters only the cavity 23 of the actuator: cylinder 9. The piston 10, pin 18 and fork 19 move to the left, reducing the pump flow until the displacement force of the servo sensor 14 of the power limiter 5 is equal to the usability of the springs 16 and 17. Output hydraulic pump parameters (produced by of the pressure P on the pitch Q) become equal to the calculated N PQ const. When the value of the injection pressure supplied through line 31 to the cavity 29 of the distributor 21 of the cut-off unit exceeds the calculated value by which the adjustable :: spring is adjustable, its pusher moves to the left, opening the way for the liquid under injection pressure to line 35 and then to the cavity 34 limiter 5 power. The area of the borehole 34 is calculated so that the force acting on the servo piston 14 becomes large enough to move it to the left all the way and move the thrust 15, the spool 12, the piston 10 to the predetermined left position, which ensures the specified minimum feed. Regulation takes place volumetricly, without loss on the safety valve. When the pressure in the discharge channel decreases, the distributor 21 returns to its initial position, the line 35 is unloaded and the force of the springs 16 and 17 moves the servo piston 14 and the piston 10 to the right gradually as the pressure in the line 35 drops. This ensures a smooth return of the swivel cage 1 with the cylinder block 2 to preset tilt angle (preset flow rate), if the remote control pressure remains the same as before the shut-off unit has triggered. If it is necessary to operate the block 4 cutoffs in the second mode (lower value of the discharge pressure), include an additional source of remote control,. Fluid on line 37 is supplied to n, the cavity 36 of the distributor 22 and moves it to the left, the pump is connected to the line 39 and then with the cavity 40 of the distributor 21. The plunger of the distributor 21 is under the action of pressure in two lanes m - 29 and 40, and therefore, it operates at a lower injection pressure. The invention allows, in accordance with the operating conditions, while maintaining a predetermined pressure, to reduce the flow of an axial-piston pump and, consequently, the proportion of flow, which is not productively discharged through a safety valve, increases the efficiency of operation of the pump 944. Invention formula 1. Axial-piston pump. Containing a housing, inside which is located a block of 1TS1 cylinders with pistons, a drive shaft mounted in bearings, a rotary pole with suction and pressure channels for the working fluid, a distributor installed on the cradle, a mechanism for changing the flow, an actuating cylinder with a piston, and a thrust rod with a piston mounted in the sleeve, the mop limiter; with a stepped servo piston, interacting with a thrust slide, and hydraulically connected to the control unit, one of the working cavities of the stepped servo The horn is connected to the working fluid injection channel, and the piston using the drill stem is kinematically connected with a swivel cradle and spool sleeve, characterized in that, in order to improve cost-effectiveness, the pump is equipped with a cut-off unit containing a hydraulically controlled spring-loaded two-way distributor, a hydraulic cavity and which is connected to the discharge channel, and the output is connected to the second working cavity of a stepped servo piston. 2. Pump POP.1, characterized in that, in order to extend the functionality by providing dual-mode operation of the cut-off unit, the cut-off unit contains an additional hydraulically operated spring-loaded distributor, and the main two-way distributor is complete with an additional hydraulic-control cavity connected to the discharge channel through an additional distributor , the hydraulic control cavity of which is connected to the control unit. 23 P 30 3 " lO rr : s 8