RU49921U1 - AXIAL PISTON REGULATED MOTOR - Google Patents

Abstract

The utility model relates to the field of adjustable hydraulic machines, namely: to axial-piston adjustable motors with variable displacement. The problem solved by the proposed device is to simplify the design, reducing the specific gravity and overall dimensions. The problem is solved in that in the axial-piston adjustable motor containing a pumping unit and a control mechanism including a differential control piston installed in the body of the control mechanism and kinematically connected with the pumping unit, a rod stock is formed between the end surface of the smaller diameter of the control piston and the body of the control mechanism cavity, between the end surface of the larger diameter of the control piston and the housing of the control mechanism, a piston cavity is formed, moto p contains two valve blocks installed in the body of the control mechanism, each of the blocks includes a direct-acting pressure relief valve and a non-return valve; two openings are made in the body of the control mechanism to provide supply / removal of the working medium, the first channel, the second channel and the third channel are made in the body of the control mechanism; the inlet of the check valve of the first valve block is connected to the first hole for supplying / discharging the working medium, and the output of the check valve of the first block is connected to the first and second channels, the inlet of the safety valve of the first block is connected to the second channel, and the outlet of the safety valve of the first block is connected to the first hole for supply / removal of the working environment; the inlet of the check valve of the second valve block is connected to the second hole for supplying / discharging the working medium, and the output of the check valve of the second block is connected to the third channel, the inlet of the safety valve of the second block is connected to the third channel, and the output of the safety valve of the second block is connected to the second hole for supplying / removal of the working environment; while the first channel on the other hand is connected to a hydraulic distributor designed to regulate the pressure in the piston cavity, and the second and third channels are connected to the rod cavity.

Description

The utility model relates to the field of adjustable hydraulic machines, namely: to axial-piston adjustable motors with variable displacement.

Known axial piston machine containing a pumping unit, including installed in the housing on bearings of the shaft of the pumping unit. The flange of the shaft is pivotally connected to the central journal and pistons included in the cylinders of the inclined block. The inclined block rotates on the central axle and rests on the distributor, which is an adjustable link of the machine. The distributor is connected by a finger to the power differential piston located in the housing of the control mechanism. The differential piston is controlled through a pressure control valve in the piston piston cavity, while the rod cavity is connected via check valves and a control valve to the inlet and outlet of the machine. The control valve, in addition, is connected to the piston cavity and to the drain, and the inlet and outlet channels of the machine are interconnected via two safety-feeding valves (Bosch Rexroth Catalog AG RE 91 606/05/99 IA 6 VE, 2005-03-17 ; website www.boschrexroth.com).

The disadvantages of the known adjustable machine selected for the prototype are:

- design complexity due to the presence of check valves simultaneously with the presence of safety-make-up valves; the presence of long channels with check valves for supplying a working medium to the control valve; the presence of two channels passing from the control valve through the entire body of the control mechanism to the piston and rod cavities. All these factors greatly complicate the manufacturing process of the known machine and are the reason for its high cost.

- insufficient reliability of the design and sensitivity of the machine, due to the fact that the presence of long channels passing through the entire body of the regulation mechanism significantly reduces the quality of regulation and increase the regulation cycle.

- significant dimensions of the machine, due to the increased thickness of the housing of the control mechanism compared to adjustable machines without safety-make-up valves.

The problem solved by the proposed utility model is to simplify the design, reduce the specific gravity and overall dimensions of the axial piston adjustable motor.

The problem is solved in that in the axial-piston adjustable motor containing a pumping unit and a control mechanism including a differential control piston installed in the body of the control mechanism and kinematically connected with the pumping unit, a rod stock is formed between the end surface of the smaller diameter of the control piston and the body of the control mechanism cavity, between the end surface of the larger diameter of the control piston and the housing of the control mechanism, a piston cavity is formed, according to As of a useful model, the motor contains two valve blocks installed in the body of the control mechanism, each of the blocks includes a safety valve and a check valve located in the block body; two openings are made in the body of the control mechanism to provide supply / removal of the working medium, the first channel, the second channel and the third channel are made in the body of the control mechanism; the check valve inlet of the first valve block is connected to the first hole for supplying / discharging the working medium, and the check valve outlet of the first block is connected to the first and second channels, the safety valve inlet of the first block is connected to the second channel, and the safety valve output of the first block is connected to the first hole for supply / removal of the working environment; the inlet of the check valve of the second valve block is connected to the second hole for supplying / discharging the working medium, and the output of the check valve of the second block is connected to the third channel, the inlet of the safety valve of the second block is connected to the third channel, and the output of the safety valve of the second block is connected to the second hole for supplying / removal of the working environment; while the first channel on the other hand is connected to a hydraulic distributor designed to regulate the pressure in the piston cavity, and the second and third channels are connected to the rod cavity.

The stock cavity can be made with an expanding diameter at its junction with the second and third channels.

The valve block can be made in the form of a back-safety valve.

The inventive axial piston adjustable motor functionally consists of two main components - the pumping unit and the regulation mechanism.

The pumping unit contains a shaft with bearings mounted in the motor housing, an inclined unit rotating on the central axle, supported by a distributor kinematically connected with a differential control piston.

The control mechanism comprises a differential control piston (hereinafter referred to as the control piston) installed in the housing of the control mechanism kinematically connected to the distributor of the pumping unit by means of a finger. On different sides of the finger, the control piston has different diameters - larger and smaller. A rod cavity is formed between the end surface of the smaller diameter of the control piston and the housing of the control mechanism; between the end surface of the larger diameter of the control piston and the housing of the control mechanism, a piston cavity is formed. The rod cavity during the operation of the motor is connected to the working pressure line. The piston cavity during operation of the motor is connected to the working pressure line through a hydraulic distributor.

The motor is regulated when the corresponding pressure is supplied from the working pressure line to the piston cavity of the control mechanism. Applying pressure to the piston cavity causes the control piston to move. When moving the control piston, the position of the distributor kinematically connected with the control piston changes. A change in the position of the distributor causes a change in the position of the inclined unit resting on the distributor, which leads to a change in the displacement of the motor.

The inventive motor comprises two valve blocks mounted in the body of the control mechanism, each of which includes a safety valve and a check valve located in the block body.

The safety valve provides a limitation of high pressure within the adjustable limits of the flow of the working medium entering the valve inlet.

The non-return valve passes the flow of the working fluid entering the valve inlet and does not pass the flow of the working fluid of the opposite direction.

In the housing of the control mechanism of the inventive motor, the first channel is made, connected on the one hand to the output of the check valve of the first valve block, and on the other hand, to the hydraulic distributor. The non-return valve of the first valve block passes the flow of the working fluid entering its inlet from line A (the first hole for supplying / discharging the working fluid), providing a connection

line A with the first channel, since the inlet of the check valve of the first valve block is connected to the first hole.

Line B (second hole for supplying / discharging the working medium) is connected to the inlet of the check valve of the second valve block.

In the housing of the regulation mechanism of the inventive motor, two channels are made (second and third, respectively), connecting line A to line B through the stock cavity. In this case, the second channel is connected to the rod cavity and to the inlet of the safety valve of the first valve block, and the third channel is connected to the rod cavity and, accordingly, to the inlet of the safety valve of the second valve block.

Thus, lines A and B are connected through the valves of both valve blocks, the second and third channels and the stem cavity.

In the case when the flow of the working medium is supplied through line A under the working (high) pressure, and the low pressure flow is passing through line B, the working fluid from line A enters the inlet of the non-return valve of the first valve block, which allows this flow connection of line A to the first channel. The working medium from line A of the working pressure through the first channel is supplied to the hydraulic distributor, and from it to the piston cavity. The hydraulic distributor controls the pressure in the piston cavity, passing a certain flow of the working medium from the first channel, the value of which is set depending on the required pressure level in the piston cavity. The position of the hydraulic distributor is controlled by an external control element. At the same time, the working medium from line A of the working pressure through the second channel enters the rod cavity and into the third channel. When the pressure in the third channel of a given level is exceeded, the safety valve of the second valve block is activated and the working medium from the third channel is discharged into line B. The response threshold of the safety valve of the second valve block is set depending on the pressure level in the third channel, which, in turn, is determined pressure level in the stock cavity.

In the case when a low pressure stream flows through line A, and a high (working) pressure stream enters through line B. The working medium from the high-pressure line B enters the check valve inlet of the second valve block, which, passing this flow, ensures the connection of line B and the third channel. The working medium enters through the third channel into the stock cavity and into the second channel. From the second channel, the working medium enters the inlet of the safety valve of the first block

valves and when the pressure in the third channel of a given level is exceeded, the safety valve is activated, the working medium from the second channel merges into line A, which is a low pressure line. The threshold of the safety valve of the first valve block is set depending on the pressure level in the second channel, which, in turn, is also determined by the pressure level in the rod cavity.

Thus, the check and safety valves of each valve block pass flows in opposite directions - the check valves pass the flows entering their inputs respectively from the direction A or B, and the safety valves pass the opposite direction flows when the pressure level in the second or third channels is exceeded, coming to the safety valve inputs from the second or third channels, respectively, in the direction of line A or B.

In order to ensure the transmission of the full flow of the working medium through the second and third channels, the rod cavity in the place of approach of these channels has an expansion in diameter.

In the inventive motor, the high and low pressure lines (the first and second openings for supplying / discharging the working medium) are interconnected by channels (second and third) made in the body of the control mechanism and connecting both lines through the stock cavity. This embodiment of these channels allows you to minimize their length, does not require additional structural elements and space for their placement. To simplify the design and minimize the dimensions of the inventive motor, it uses not separate types of valves (check and safety), but valve blocks combining safety and check valves in one housing, these valve blocks are installed directly in the control mechanism housing. The proper functioning of the valve blocks is ensured by the fact that the second and third channels are connected to the inputs of the corresponding safety valves, lines A and B are connected to the inputs of the corresponding check valves, and the output of the check valve of the first back-safety valve is connected to the first channel, also connected to the hydraulic distributor. Thus, through the first channel, the working medium is supplied from line A to the piston cavity.

Thus, the connection of both lines (A and B) in the inventive motor through channels made in the housing of the control mechanism and passing through the rod cavity, eliminates long channels from its design, which

provides an increase in the quality and reliability of the motor as a whole, reduction of the regulation cycle time. In addition, such a constructive implementation of the inventive motor allows you to exclude from its design additional devices that ensure the discharge of the working medium from the rod cavity when pressure is increased in the piston cavity. When the control piston moves upward, the working medium from the rod cavity is discharged into the third channel, and from there through the safety valve of the second valve block to line B (when line B is the low pressure line), or into the second channel, and from there through the safety valve of the first valve block to line A (when line A is a low pressure line).

The use of the inventive motor valves (check and safety), placed in pairs in the corresponding valve blocks mounted directly in the housing of the control mechanism allows to simplify the design of the motor and, therefore, also increase the reliability of its operation; allows to reduce the specific gravity and dimensions of the motor.

The connection of the second and third channels through the piston cavity ensures the flow of the working medium into the piston cavity in any direction of the working medium (from line A to line B and vice versa). The necessary level of pressure in the piston cavity is ensured by setting the appropriate level of operation of the safety valves of both valve blocks.

Thus, the connection of lines A and B and the supply of the piston cavity are provided through the same channels, which eliminates the need for special channels to supply the working medium from line A or B to the piston cavity and the connection of both lines.

To further reduce weight and size indicators and simplify the design in the inventive motor, it is advisable to use directly back-pressure valves, combining the functions of a check valve and a safety valve, as a valve block.

Non-return valves provide a flow passage of the working medium in one direction (in the non-return valve mode), and in the safety valve mode, the flow passes in the opposite direction when the pressure of the working medium in the corresponding channel or cavity of a given level is exceeded.

When using back-safety valves, they should be installed in such a way that the flow coming from line A (the first inlet for supplying / discharging the working medium) passes through the first back-safety valve

a valve operating in the non-return valve mode to the first and second channels, and then through the second channel, the piston cavity and the third channel, from the third channel, the flow will flow into the second back-safety valve operating in the safety valve mode and transmitting, respectively, the flow - to line B (second hole for supplying / discharging the working medium). Thus, two back-safety valves installed in the motor will work in opposite modes:

if the first back-pressure relief valve operates in the non-return valve mode, the second back-pressure relief valve will work, respectively, in the safety valve mode and vice versa.

In the case when the flow of the working medium will come from line B, the second back-pressure relief valve in the check valve mode should ensure the connection of line B with line A through the third and second channels and the piston cavity, i.e. to ensure the flow of the working fluid from line B to the third channel, then to the second channel, from the second channel, the flow should be passed by the first back-pressure relief valve operating in the safety valve mode to line A.

Those. when using back-pressure relief valves, they must be installed with the possibility of connecting the line A to the first and second channels through the first back-pressure valve operating in the non-return valve mode, and connecting the third channel to line B through the second back-pressure valve working in safety valve mode for passing the flow coming from line A to line B. And vice versa: to pass the flow coming from line B to line A, the back-safety valves must It is set to connect the line A to a second channel through the first back-relief valve operating mode of the safety valve, and a connection line in a third channel through the second back-pressure relief valve, operating in the check valve mode.

Figure 1 presents the inventive axial piston adjustable motor.

Figure 2 - section D.

Figure 3 - hydraulic circuit of the motor.

The axial piston motor with an adjustable displacement includes a housing 1, in which a shaft 3 with a flange 4 is mounted on the bearings 2. The flange 4 is pivotally connected to the pistons 5 and the central pin 6. The pistons 5 are located in the cylinders 7 of the inclined block rotating around the axis of the central pin 6 8, which is driven into rotation by the flange 4 of the shaft 3 and the pistons 5. The stroke of the pistons 5 is determined by the angle

rotation formed by the axis of rotation of block 8 and the axis of rotation of the shaft 3. Block 8 is supported by a distributor 9 adjacent to the housing 10 of the control mechanism on the supporting surface of rotation. The distributor is pressed against the housing 10 under the action of the force of the spring 11 and hydraulic pressure in the cylinders 7 of the block 8.

The regulation of the working volume of the motor is ensured by the sliding of the distributor 9 along the supporting surface of rotation of the housing 10 along the guides 12. The movement of the distributor 9 along the supporting surface of rotation of the housing 10 is carried out by a differential (step) control piston 13 by means of a pin 14 entering the opening 15 of the distributor 9. The control piston 13 is made consisting of two longitudinal sections - a larger and a smaller diameter, a section of a smaller diameter of the piston 13 is placed in the cavity 16 - rod cavity, the piston section 13 b a larger diameter is placed in the cavity 17 - the piston cavity. Cavities 16 and 17 are made in the housing 10 of the regulation mechanism.

The cavities 16 and 17 of the piston 13 are located on opposite sides with respect to the pin 14. The rod cavity 16 is permanently connected by channels 22 or 23 to line A (connected to the motor input) through check valves 18, 19 of the valve blocks (back safety valves) 20 and 21 ) or line B (connected to the motor output). Line A and line B - are made in the form of corresponding holes (first and second) in the housing 10. As a back-safety valve, a valve according to the RF patent No. 2028531 "Back-pressure safety valve" can be used

The housing 10 on the side of the piston cavity 17 is closed by a cover 24, in which a hydraulic distributor is installed, containing a control valve 25 containing a spool 26. The cover 24 and the control valve 25 has a channel 27 connected to the piston cavity 17. The control valve 25 through the channel 28 in the cover 24 and channel 29 (the first channel according to the utility model) in the housing 10 is connected to the cavity 30 of the first back-pressure relief valve 21. In the lid 24 there is a channel 31 connected to the tank 32 for draining the working medium from the piston cavity.

Line A and line B are interconnected by back-safety valves 20 and 21 of the channels 22, 23 (respectively, the second and third channels according to the utility model), passing through the rod cavity 16 of the piston 13. To pass the full flow from the valves, the rod cavity 16 has an extension 33 in diameter along the approach to her channels 22, 23.

The axial-piston adjustable motor according to the claimed solution has smaller overall dimensions and weight and has a simpler device.

The inventive motor operates as follows.

The motor functionally consists of two nodes: the pumping node and the regulation mechanism. The pumping unit consists of a shaft 3 with bearings 2 and an inclined cylinder block 8 with pistons 5 rotating on a central axle 6 and a distributor 9 kinematically connected with the piston 13.

The regulation mechanism is designed to change the working volume of the piston motor by changing the angle of inclination of the block 8 to the axis of the shaft 3.

The regulator includes a finger 14 entering the hole 15 of the distributor 9 and mounted transversely in the piston 13 having cavities 16 and 17 located on opposite sides of the finger 14. The control valve 25 located in the cover 24 depending on the control action on the spool 26 can regulate the pressure in the piston cavity 17.

In the neutral position of the spool 26, the pressure forces acting on the differential piston 13 are balanced. During operation, when the magnitude of the control action on the spool 26 changes, resulting in a change in the position of the spool 26, the pressure in the piston cavity 17 of the piston 13 changes, changing the ratio of forces to the piston 13, which causes moving the last one. When moving the piston 13 associated with the distributor 9 with the finger 14, the angle of inclination of the block 8 to the axis of the shaft 3 changes and the working volume of the motor changes.

In the case when a flow of a working medium under high pressure comes from line A, then a flow of a working medium under low pressure goes through line B. The working medium from line A through the back-pressure relief valve 21 operating in the non-return valve mode enters the channel 29 and into the channel 23. From the channel 23, the working medium enters the rod cavity 33 and into the channel 22. When the pressure of the working medium in the channel 22 is exceeded above the specified value, the working medium through the back-pressure relief valve 20, operating in the safety valve mode, enters line B for discharge. At the same time, from the line A, the working medium enters the channel 29, and from there through the hydraulic distributor into the piston cavity 17 for the process of regulating the motor.

Further, in the process of regulating the motor with increasing pressure in the piston cavity 17, the piston 13 moves upward, reducing the volume of the rod cavity 33. In this case, the working medium from the cavity 33 is discharged through the channel 22 and back-safety

valve 20, operating in the check valve mode, to line B, providing in this way the necessary level of pressure in the rod cavity.

If it is necessary to reduce the pressure in the piston cavity 17 during the regulation of the motor, the working medium from the piston cavity 17 is discharged through the channel 31, the piston 13 moves downward, increasing the volume of the rod cavity 33. The pressure in the rod cavity 33 is maintained by supplying the working medium from line A through the channel 23 into the stock cavity 33.

The motor works similarly in the case when the high-pressure medium enters from line B. Only in this case, does the medium come from line B through the back-pressure relief valve 20, operating in the non-return valve mode, through channel 22 to the rod cavity 33 and then to channel 23. From channel 23, the working medium merges into line A when the pressure of the working medium in channel 23 of a predetermined level is exceeded.

Claims (3)

1. An axial-piston adjustable motor containing a pumping unit and a control mechanism, including a differential control piston installed in the body of the control mechanism and kinematically connected with the pumping unit, a rod cavity is formed between the end surface of the smaller diameter of the control piston and the case of the control mechanism, between the end surface a larger diameter of the control piston and the body of the control mechanism a piston cavity is formed, characterized in that the motor contains two valve blocks embedded in the body of the control mechanism, each of the blocks includes a safety valve and a non-return valve placed in the body of the unit, two openings are made in the body of the control mechanism for supplying / discharging the working medium, the first channel, the second channel and the third are made in the body of the control mechanism the channel, the check valve input of the first valve block is connected to the first hole for supplying / discharging the working medium, and the check valve output of the first block is connected to the first and second channels, d the safety valve of the first block is connected to the second channel, and the output of the safety valve of the first block is connected to the first hole for supplying / discharging the working medium, the inlet of the check valve of the second valve block is connected to the second hole for supplying / discharging the working medium, and the output of the check valve of the second block connected to the third channel, the inlet of the safety valve of the second block is connected to the third channel, and the output of the safety valve of the second block is connected to the second hole for supply / removal of working medium, while the first channel on the other hand is connected to a hydraulic distributor designed to regulate the pressure in the piston cavity, and the second and third channels are connected to the rod cavity. 2. The axial piston adjustable motor according to claim 1, characterized in that the rod cavity is made with an expanding diameter at its junction with the second and third channels. 3. The axial piston adjustable motor according to claim 1, characterized in that the valve block is made in the form of a back-safety valve.