Detailed Description
In order to make the technical solutions of the present invention better understood, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.
The embodiment of the invention discloses a method for adjusting the displacement of a variable displacement pump, which enables the displacement of the variable displacement pump to meet the requirement of a hydraulic system on hydraulic oil, and is particularly used for meeting the change of the requirement of the hydraulic oil generated by the action change of an actuating element (such as a hydraulic cylinder and a hydraulic motor) in the hydraulic system so as to enable a working device of engineering machinery to change the action. For example, when the hydraulic system changes in speed due to the change of the working condition of a hydraulic actuator (such as a hydraulic oil cylinder and a hydraulic motor) to change the demand of the hydraulic system for hydraulic oil, the displacement of the variable pump can meet the demand of the hydraulic system for hydraulic oil by using the adjusting method provided by the invention. That is, the adjusting method of the present invention is to change the displacement of the variable displacement pump to meet the demand of the hydraulic system for hydraulic oil, rather than changing the rotation speed of the variable displacement pump according to the external power to meet the demand of the hydraulic system for hydraulic oil. The adjusting method provided by the invention specifically comprises the following steps:
before the adjusting method is introduced, the structure of the variable displacement pump is introduced. As shown in fig. 1 to 5, the variable displacement pump includes a housing 10, a stator housing 20 disposed in the housing 10, a rotor core 30 disposed in the stator housing 20, a plurality of plungers 31 circumferentially arranged on the rotor core 30, and a driving mechanism, wherein the stator housing 20 and the rotor core 30 have an eccentricity such that when external power drives the rotor core 30 to rotate, the plungers 31 perform alternating extension and compression, thereby causing the variable displacement pump to suck and discharge hydraulic oil to be supplied to a hydraulic system, and the larger the eccentricity is, the larger the flow rate of hydraulic oil discharged by the variable displacement pump is (i.e., the larger the displacement of the variable displacement pump is), and the smaller the eccentricity is, the smaller the flow rate of hydraulic oil discharged by the variable displacement pump is.
The method for adjusting the displacement of the variable displacement pump comprises the following steps:
and acquiring the actual pressure of a system pipeline in the hydraulic system in which the variable displacement pump is positioned. In this step, the actual pressure of the hydraulic oil in the system line (i.e., the actual pressure of the hydraulic system) may be measured using a pressure measuring device (e.g., a pressure sensor and a pressure gauge) having a signal output function connected to the system line.
Comparing the actual pressure with a rated working pressure of the hydraulic system (the rated working pressure is the pressure for ensuring the normal work of each element of the hydraulic system); when the actual pressure is greater than the working pressure, the driving mechanism is used for driving the stator sleeve 20 to enable the stator sleeve 20 to move towards the direction of reducing the eccentricity so as to reduce the displacement of the variable displacement pump, and further the actual pressure is adjusted to be the working pressure or the vicinity of the working pressure; when the actual pressure is smaller than the working pressure, the driving mechanism is used for driving the stator sleeve 20 to enable the stator sleeve 20 to move towards the direction of increasing eccentricity so as to enable the displacement of the variable displacement pump to be increased and enable the actual pressure to be adjusted to be at or near the working pressure; the eccentricity is the distance between the center of the stator can 20 and the center of the rotor core 30. In this step, the actual pressure is compared with the working pressure by a processor electrically connected to the pressure measuring device, for example, a pressure value of the working pressure of the hydraulic system is pre-stored in the processor, then the pressure value of the actual pressure obtained from the pressure measuring device is compared with the pressure value of the working pressure by the processor, and then the driving mechanism is controlled by a controller electrically connected to the processor, so that the driving mechanism drives the stator housing 20 to move. In this embodiment, the driving mechanism may be a mechanical driving mechanism (e.g., a nut and screw mechanism), a hydraulic driving mechanism (e.g., a hydraulic cylinder), or an electromagnetic driving mechanism (e.g., an electromagnet and a magnetic ram).
The method for adjusting the displacement of the variable displacement pump disclosed by the invention has the advantages that:
the displacement adjusting method of the variable pump not only meets the requirement of an executive element on the flow of the hydraulic oil, but also enables the executive element and a control element in the hydraulic system to normally work under the working pressure, thereby avoiding the damage to the executive element and the control element caused by overhigh pressure of the hydraulic system due to the displacement of the variable pump after the displacement adjustment, and simultaneously avoiding the incapability of meeting the requirement of realizing the action of the executive element due to low pressure.
It should be noted that: the applicant finds that judging whether the displacement of the variable pump meets the requirement of the hydraulic system actually judges whether the displacement of the variable pump meets the requirement of the action speed of the executing element, and judging whether the displacement of the variable pump meets the requirement of the action speed of the executing element can be known by measuring the actual pressure of the hydraulic oil in a pipeline of the system.
Compared with the method for adjusting the displacement of the variable pump by measuring the flow of the hydraulic oil at the outlet of the variable pump and comparing the flow with the actual required flow obtained by calculation in the prior art (the method in the prior art does not consider the pressure condition of the whole hydraulic system, which can cause that the pressure of the whole hydraulic system is too high to cause instability of the whole system and easily damage control elements such as an overflow valve and the like when the displacement of the variable pump meets the action requirement of an execution element).
In a preferred embodiment of the invention, a method for adjusting the displacement of a preferably variable displacement pump is proposed, which method combines the result of a comparison of the actual pressure with the operating pressure and the pressure difference between the two to adjust the displacement of the variable displacement pump. Specifically, when the actual pressure is greater than the working pressure and the difference between the actual pressure and the working pressure is less than the preset pressure difference, the stator can 20 is driven by the driving mechanism to move linearly in a first direction perpendicular to the axis of the rotor core 30 to reduce the eccentricity; when the actual pressure is smaller than the working pressure and the difference between the working pressure and the actual pressure is smaller than the preset pressure difference, the driving mechanism is used for driving the stator sleeve 20 to linearly move towards the reverse direction of the first direction perpendicular to the axis of the rotor core 30 so as to increase the eccentricity; when the actual pressure is smaller than the working pressure and the difference between the working pressure and the actual pressure is greater than the preset pressure difference, as shown in fig. 3, after the driving mechanism is used to drive the stator sleeve 20 to move linearly in the direction opposite to the first direction perpendicular to the axis of the rotor core 30, as shown in fig. 4 and 5, the driving mechanism is used to drive the stator sleeve 20 to move in the second direction perpendicular to the axis of the rotor core 30, so as to finally increase the eccentricity; when the actual pressure is greater than the working pressure and the difference between the actual pressure and the working pressure is greater than the preset pressure difference, the driving mechanism is used for driving the stator sleeve 20 to linearly move towards a first direction perpendicular to the axis of the rotor core 30, and then the driving mechanism is used for driving the stator sleeve 20 to move towards a second direction perpendicular to the axis of the rotor core 30 or move in the opposite direction of the second direction, so that the eccentricity is finally reduced; wherein: before the stator sleeve 20 moves towards the first direction, when the eccentricity between the rotor core 30 and the stator sleeve 20 is 0, the first direction is any radial direction passing through the center of the rotor core 30; when the eccentricity between the rotor core 30 and the stator sleeve 20 is not 0, the first direction is a direction determined by a connecting line of the center of the rotor core 30 and the center of the stator sleeve 20; the included angle between the first direction and the second direction is larger than 0 degree and smaller than 90 degrees.
The above-described embodiments propose a more specific and preferred adjustment method that allows for the adjustment of the displacement of the variable displacement pump by taking different adjustments to the eccentricity for the extent to which the actual pressure deviates from the working pressure.
The adjusting method provided by the above embodiment can be specifically understood as follows: when the pressure difference between the actual pressure and the working pressure is small (the magnitude of the pressure difference is judged based on the preset pressure difference), namely, the degree of the actual pressure deviating from the working pressure is small, the driving mechanism is used for driving the stator sleeve 20 to move in the first direction to enable the eccentricity to meet the displacement required to be adjusted by the variable displacement pump; when the pressure difference between the actual pressure and the working pressure is large, that is, the actual pressure deviates from the working pressure to a large extent, as shown in fig. 3, the stator sleeve 20 is first driven by the driving mechanism to move linearly in the first direction, and then, as shown in fig. 4 and 5, the stator sleeve is moved in the second direction by the driving mechanism, so that the final eccentricity meets the displacement required to be adjusted by the variable displacement pump. The preset pressure difference is set according to the working pressure, and is generally about one tenth of the working pressure.
The advantages of the adjustment method provided by the above embodiment are:
when the degree that actual pressure deviates from operating pressure is less, the adjustment sensitivity of the discharge capacity of the variable displacement pump is the key point, at this moment, the stator sleeve 20 is driven to move in one direction, so that the eccentricity can be rapidly adjusted to the discharge capacity required by the variable displacement pump, and therefore the actual pressure is rapidly adjusted to the operating pressure, and the effect of sensitive reaction is achieved.
When the actual pressure deviates from the working pressure to a large extent, the adjustment precision of the displacement of the variable pump becomes a key point, and at the moment, the stator sleeve 20 is driven to linearly move in the first direction to rapidly adjust the eccentricity to an intermediate eccentricity es which is closer to the final eccentricity, so that the eccentricity is roughly adjusted once, and correspondingly, the displacement of the variable pump is also roughly adjusted correspondingly; after the rough adjustment of the eccentricity is completed, the stator sleeve 20 is driven to move in the second direction, so that the eccentricity is precisely adjusted once, the final eccentricity en is obtained, and the displacement of the variable pump is precisely adjusted twice to meet the requirement of the system on the flow.
The advantage of adjusting the eccentricity by driving the stator can 20 in two directions one after the other when the actual pressure deviates to a greater extent from the operating pressure is: when driving in the first direction, the driving displacement of the driving mechanism is totally used for contributing to the eccentricity (i.e. the driving displacement is equal to the variation et of the eccentricity), how much the variation et of the eccentricity is generated by how much driving displacement, so that the eccentricity is quickly adjusted, but the characteristic that the driving displacement totally contributes to the eccentricity cannot be used for accurately adjusting the eccentricity, only coarse adjustment can be performed on the eccentricity, and after the stator sleeve 20 completes the movement in the first direction, the driving displacement (H1, H2) in the second direction only partially contributes to the eccentricity, that is, as shown in fig. 4 and 5, the variation ed of the eccentricity is smaller than the driving displacement (H1, H2) in the second direction, so that the variation of the eccentricity contributed by the unit driving displacement in the second direction is much smaller than the eccentricity contributed by the unit driving displacement in the first direction, thus, driving the stator can 20 in the second direction enables a higher adjustment accuracy of the eccentricity.
As can be seen from the above, the eccentricity adjustment by driving the stator sleeve 20 in two directions in the above embodiment can satisfy both the requirement of sensitive adjustment and the requirement of adjustment precision.
It should be noted that: as shown in fig. 1 and 2, when the variable displacement pump is started from a state in which the eccentricity is 0 (at this time, the variable displacement pump is mostly used as a supplemental oil pump), the initial eccentricity e0 is obtained by the driving mechanism driving the stator housing 20 in the first direction.
The driving of the stator housing 20 in two directions by the driving mechanism may be achieved by two driving parts (the two driving parts serve as the driving mechanism), namely, a first driving part 40 and a second driving part 50, the first driving part 40 is used for driving the stator housing 20 to move in a first direction, and the second driving part 50 is used for driving the stator housing 20 to move in a second direction.
And the second driving part 50 drives the stator casing 20 to move in the second direction in two forms:
the first method is as follows: the stator can 20 is driven to move linearly in the second direction, and in a preferred embodiment, the second driving part 50 drives the stator can 20 to move linearly in a direction perpendicular to the first direction, as shown in fig. 4.
The second method is as follows: the stator can 20 is driven to rotate about a center in the second direction, and in a preferred embodiment, as shown in fig. 5, the second driving portion 50 initially drives the stator to rotate about a center in a direction perpendicular to the first direction. In this type of movement, the stator can 20 is rotatably connected to the housing 10.
As shown in fig. 4 and 5, the two predetermined forms can make the driving displacement smaller than the variation of the eccentricity, thereby illustrating that the driving displacement does not completely contribute to the eccentricity, and further verifying that the moving process of the stator sleeve 20 in the second direction is a process of precisely adjusting the eccentricity.
As shown in fig. 6 to 18, the present invention also discloses a variable displacement pump including a housing 10, a stator case 20, a rotor core 30, a plurality of plungers 31, and a driving mechanism. Wherein, the shell 10 is a detachable split structure, and the shell 10 is provided with a containing cavity therein; the stator sleeve 20 is arranged in the accommodating cavity and can move in the accommodating cavity, and the accommodating space of the accommodating cavity is larger than that of the stator sleeve 20, so that the stator sleeve 20 can have a certain movement allowance in the accommodating cavity; a rotor core 30 is arranged in the stator housing 20, the rotor core 30 having one end axially protruding out of the casing 10, the one end being connected to an external power component, for example, directly connected to an external driving motor, or connected to the external driving motor through a gearbox, the power component being used for driving the rotor core 30 to rotate; a plurality of plungers 31 are circumferentially arranged around the rotor core 30, one end of each plunger 31 is hinged with the rotor core 30, the other end of each plunger 31 is connected with the inner wall of the stator sleeve 20 in a sliding mode, when the rotor core 30 rotates, the plurality of plungers 31 simultaneously rotate along with the rotor core 30, when the stator sleeve 20 and the rotor core 30 have a certain eccentricity (the eccentricity is the distance between the centers of the stator sleeve 20 and the rotor core 30), the plurality of plungers 31 alternately extend or compress along with the rotation of the rotor core 30 to suck oil and discharge oil (the oil discharge amount of the plurality of plungers 31 is the displacement of the variable pump), the discharged oil is used for supplying a hydraulic system where the variable pump is located, and the alternate extension and compression amount of the plungers 31 is changed by changing the eccentricity to change the displacement of the variable pump; the driving mechanism comprises a first driving part 40 and a second driving part 50, and the first driving part 40 generates driving displacement through a self part to drive the stator sleeve 20 to move linearly in a first direction; the second driving part 50 is used for driving the stator sleeve 20 to move towards a second direction after the first driving part 40 finishes driving the stator sleeve 20 in the first direction, in this embodiment, the second direction is different from the first direction, and the first direction and the second direction are both directions perpendicular to the axis of the rotor core 30. The second direction is different from the first direction, which means that the first direction and the second direction have a certain included angle, which is selected to be larger than 0 ° and smaller than 180 °, and before the stator sleeve 20 moves towards the first direction, when the eccentricity between the rotor core 30 and the stator sleeve 20 is 0, the first direction is any radial direction passing through the center of the rotor core 30; when the eccentricity between the rotor core 30 and the stator sleeve 20 is not 0, the first direction is a direction determined by a line connecting the center of the rotor core 30 and the center of the stator sleeve 20.
The variable pump can meet the requirements of different displacement adjustment amounts, has the advantages of high adjustment sensitivity and high adjustment precision, and has the advantages of more obvious adjustment sensitivity and high adjustment precision when the displacement is adjusted according to the actual pressure in the system pipeline of the hydraulic system where the variable pump is located.
The method and the process of the variable displacement pump for adjusting the displacement according to different pressures of the system pipeline are as follows:
when the actual pressure (which is obtained by a pressure measuring device connected to a system pipeline, the pressure measuring device may be a pressure sensor and a pressure gauge) is greater than the working pressure (the pressure in the hydraulic system for the normal operation of each control element and the actuator) and the difference between the actual pressure and the working pressure is less than a preset pressure difference, the stator housing 20 is driven by the first driving part 40 to move linearly in a first direction perpendicular to the axis of the rotor core 30 to reduce the eccentricity; when the actual pressure is less than the working pressure and the difference between the working pressure and the actual pressure is less than the preset pressure difference, the stator casing 20 is linearly moved in the opposite direction of the first direction perpendicular to the axis of the rotor core 30 by the first driving part 40 to increase the eccentricity; when the actual pressure is smaller than the working pressure and the difference between the working pressure and the actual pressure is greater than the preset pressure difference, as shown in fig. 12, after the first driving part 40 is used to drive the stator sleeve 20 to move linearly in the first direction perpendicular to the axis of the rotor core 30, as shown in fig. 15, the second driving part 50 is used to drive the stator sleeve 20 to move in the second direction perpendicular to the axis of the rotor core 30, so as to finally increase the eccentricity; when the actual pressure is greater than the working pressure and the difference between the actual pressure and the working pressure is greater than the preset pressure difference, the first driving part 40 drives the stator sleeve 20 to linearly move in the opposite direction of the first direction perpendicular to the axis of the rotor core 30, and then the second driving part 50 drives the stator sleeve 20 to move in the opposite direction of the second direction perpendicular to the axis of the rotor core 30, so as to finally reduce the eccentricity (the moving process and state of the stator sleeve 20 in this case are not shown in the drawing).
The manner and process of the variable displacement pump of the above embodiment to adjust the displacement can be understood as follows: when the pressure difference between the actual pressure and the working pressure is small (the magnitude of the pressure difference is judged based on the preset pressure difference), namely, the degree of the deviation of the actual pressure from the working pressure is small, the first driving part 40 is utilized to drive the stator sleeve 20 to move in the first direction, so that the eccentricity meets the displacement required to be adjusted by the variable displacement pump; when the pressure difference between the actual pressure and the working pressure is large, that is, the actual pressure deviates from the working pressure to a large extent, as shown in fig. 12, the stator sleeve 20 is first driven by the first driving portion 40 to move linearly in the first direction, and then, as shown in fig. 15, the stator sleeve 20 is driven by the second driving portion 50 to move in the second direction, so that the final eccentricity meets the displacement required to be adjusted by the variable displacement pump. The preset pressure difference is set according to the working pressure, and is generally about one tenth of the working pressure.
The variable displacement pump provided by the above embodiment has advantages in adjusting the displacement:
when the degree that actual pressure deviates from operating pressure is less, the adjustment sensitivity of the discharge capacity of the variable displacement pump is the key point, at this moment, the stator sleeve 20 is driven to move in one direction, so that the eccentricity can be rapidly adjusted to the discharge capacity required by the variable displacement pump, and therefore the actual pressure is rapidly adjusted to the operating pressure, and the effect of sensitive reaction is achieved.
When the actual pressure deviates from the working pressure to a large extent, the adjustment precision of the displacement of the variable pump becomes a key point, and at the moment, the stator sleeve 20 is driven to linearly move in the first direction to rapidly adjust the eccentricity to an intermediate eccentricity closer to the final eccentricity, so that the eccentricity is roughly adjusted once, and correspondingly, the displacement of the variable pump is also roughly adjusted correspondingly; after the rough adjustment of the eccentricity is completed, the stator sleeve 20 is driven to move in the second direction, so that the eccentricity is precisely adjusted once, the final eccentricity is obtained, and the displacement of the variable displacement pump is precisely adjusted twice to meet the requirement of the system on the flow.
The above-described embodiment provides a greater advantage for the displacement pump when the actual pressure deviates to a greater extent from the working pressure: when driving in the first direction, the driving displacement of the first driving part 40 is all used to contribute to the eccentricity, and how much driving displacement produces how much variation of the eccentricity, so that the eccentricity is quickly adjusted, the driving displacement is totally contributed to the characteristic of the eccentricity, but the eccentricity can not be accurately adjusted, and only the eccentricity can be coarsely adjusted, and after the stator sleeve 20 finishes moving in the first direction, only a partial contribution of the driving displacement in the second direction to the eccentricity, i.e. an amount of change of the eccentricity, is smaller than the driving displacement in the second direction, so that, the amount of change in eccentricity contributed by the unit driving displacement in the second direction is much smaller than the eccentricity contributed by the unit driving displacement in the first direction, and therefore, driving the stator can 20 in the second direction enables a higher adjustment accuracy of the eccentricity.
According to the above, when the variable displacement pump provided by the above embodiment is applied to a hydraulic system with large pressure fluctuation, the stator sleeve 20 is driven by the two driving portions to move in two directions, so that the adjustment of the eccentricity can meet the requirements of both sensitive adjustment and precision adjustment.
In a preferred embodiment of the present invention, as shown in fig. 6 to 18, the first driving part 40 includes a first driving group and a first balancing group 41; the second driving part 50 includes a second driving group and a second balancing group 51; wherein: the first driving group and the first balance group 41 are symmetrically arranged in the shell 10; the second driving group and the second balancing group 51 are symmetrically arranged in the housing 10; the circumferential arrangement position of the first drive group is 90 ° from the circumferential arrangement position of the second drive group. In the present embodiment, the first driving portion 40 and the second driving portion 50 both drive the stator can 20 to move in contact with and push against the stator can 20 to change the eccentricity. In the present embodiment, the arrangement of the first driving part 40 and the second driving part 50 shows that in the embodiment, the first direction and the second direction of the movement of the stator can 20 are perpendicular, and the first driving part 40 and the second driving part 50 are arranged in such a way that: the ratio of the driving displacement obtained by the stator sleeve 20 to the variation of the corresponding eccentricity is maximized, thereby improving the final adjustment precision of the eccentricity to the maximum extent.
It should be noted that: the first driving group and the first balancing group 41 cooperate to drive the stator sleeve 20 to move linearly in a first direction, for example, when the force applied by the first driving group is greater than that applied by the first balancing group 41, the stator sleeve 20 is driven by the first driving group to move linearly in the first direction (as shown in fig. 12), and when the force applied by the first balancing group 41 is greater than that applied by the first driving group, the stator sleeve 20 is driven by the first balancing group to move linearly in the opposite direction of the first direction (this is not shown in the drawings); for another example, when the force applied by the second driving group is greater than that applied by the second balancing group 51, the stator housing 20 is driven by the second driving group to move in the second direction (as shown in fig. 15), and when the force applied by the second balancing group 51 is greater than that applied by the second driving group, the stator housing 20 is driven by the second balancing group 51 to move in the opposite direction of the second direction (this is not shown in the drawings).
In a preferred embodiment of the present invention, as shown in fig. 6 to 18, a left guide chamber and a right guide chamber penetrating to the receiving chamber are formed at the left and right sides of the housing 10, respectively; the first driving group comprises a driving piston 42 which is arranged in the left guide cavity and can slide along the left guide cavity to push against the stator sleeve 20, and a first spring 43 which is arranged in the left guide cavity and is abutted against the driving piston 42; the first balance group 41 includes a first balance piston 411 disposed in the right guide cavity and capable of sliding along the right guide cavity to push against the stator sleeve 20, a buckle cover 413 fixed on the housing 10, a second spring 412 disposed between the first balance piston 411 and the buckle cover 413, and an adjusting screw 414 disposed through the buckle cover 413 and used for pushing against the second spring 412 to adjust the compression degree thereof (after the compression degree is adjusted, it is locked by a locking nut 415). In this embodiment, a control valve member 60 is disposed outside the left side of the housing 10, external control hydraulic oil (the control hydraulic oil may be from a hydraulic system or supplied by hydraulic oil) enters the left guide cavity through the control valve member 60, the power of the driving piston 42 for driving the stator sleeve 20 is controlled by the pressure of the control hydraulic oil, so that the driving piston 42 can drive the stator sleeve 20 to move in the first direction, when the stator sleeve 20 moves to a predetermined eccentricity, the first spring 43 and the control hydraulic oil balance the acting force on the stator sleeve 20 with the acting force of the second spring 412 on the stator sleeve 20 through the first balance piston 411, and at this time, before the stator sleeve 20 is not subjected to other acting forces, the position of the stator sleeve 20 after moving in the first direction is maintained, and the corresponding eccentricity is maintained at a certain magnitude. In the present embodiment, the adjusting screw 414 is used to adjust the second spring 412, so that when the pressure of the control hydraulic oil in the left guide cavity is extremely small or the control hydraulic oil is not supplied in the left guide cavity and the stator housing 20 is in a position such that the eccentricity is 0 (as shown in fig. 6 to 8), the first spring 43 and the second spring 412 are balanced by the forces of the driving piston 42 and the balancing piston on the stator housing 20 (as shown in fig. 6).
In a preferred embodiment of the present invention, the left side of the stator can 20 is provided with a pivot 23, and the pivot 23 is rotatably pivoted to the driving piston 42 by a pin 44. An upper through groove and a lower through groove which penetrate through the accommodating cavity are formed on the upper side and the lower side of the shell 10 respectively. The second drive group includes a lower holding case 571, a mounting body 57, an electromagnet, a deforming body 52, a first shoe 55, and a drive body 54; the lower retaining shell 571 is fixed on the lower side of the outer shell 10; the mounting body 57 is fixed in the lower retaining shell 571, and the mounting body 57 has a mounting groove and a vertically through guide groove; the electromagnet 53 comprises an iron core and a coil wound on the iron core, and the electromagnet 53 is arranged in the mounting groove to form a horizontal magnetic induction line; the deformable body 52 is made of cylindrical magnetic memory metal, the deformable body 52 is vertically arranged in the guide groove, and a magnetic induction line can penetrate through the deformable body 52; the driving body 54 is arranged in the guide groove and above the deformation body 52, so that when the deformation body 52 is subjected to magnetic induction, the deformation body 52 vertically grows to drive the driving body 54 to vertically move upwards; the tail part of the first sliding shoe 55 is hinged with the upper end of the driving body 54, and the head part of the first sliding shoe is arranged into a cylindrical surface matched with the outer periphery of the stator sleeve 20 and passes through the lower through groove to be attached to the stator sleeve 20; the second balance group 51 includes an upper holding case 512, a third spring 513, a top cover 511, a second balance piston 515, and a second slipper 516; an upper holding case 512 is fixed to the upper side of the casing 10, a second balance piston 515 is disposed in the upper holding case 512, a third spring 513 is disposed in the upper holding case 512 and pushes the second balance piston 515, a tail portion of a second shoe 516 is hinged to the second balance piston 515, and a head portion thereof is disposed as a cylindrical surface matching the outer circumference of the stator can 20 and passes through the upper through groove to be attached to the stator can 20. Preferably, the adjusting nut 56 is disposed below the deformable body 52, and the fourth spring 59 for pushing the deformable body 52 is further disposed above the deformable body 52, and the fourth spring 59 is used for removing the deformation margin which cannot be recovered after the deformable body 52 loses the magnetic induction effect.
As shown in fig. 12 to 14, when the first driving portion 40 finishes driving the stator sleeve 20 in the first direction, the electromagnetic coil is energized, and the electromagnet generates a magnetic induction line passing through the magnetic memory metal, so that the magnetic memory metal is deformed in the direction of the stator sleeve 20, and further the driving body 54 is driven to move in the direction of the stator sleeve 20, and further the first shoe 55 pushes the stator sleeve 20 to rotate in the second direction until the eccentricity reaches the final adjustment position.
It should be noted that: as shown in fig. 15 to 18, while the first slipper 55 drives the stator sleeve 20 to rotate, the stator sleeve 20 drives the second balance piston 515 to move away from the stator sleeve 20 through the second slipper 516, and thus third spring 513, and ultimately third spring 513, balances the force of second balance piston 515 and second shoe 516 against stator can 20 with the force of first shoe 55 against stator can 20, thereby balancing the forces experienced by the stator can 20 in the second direction, so that the eccentricity is kept stable, when it is required to move the stator sleeve 20 in the second direction in the reverse direction, and the current applied to the electromagnetic coil is reduced, the deformation amount of the magnetic memory metal is reduced, and the third spring 513 pushes the stator sleeve 20 in the reverse direction through the second balance piston 515 and the second shoe 516, so that the stator sleeve 20 moves to the balance position where the eccentricity reaches the desired magnitude.
In the above embodiment, since the stator can 20 is rotatably connected to the driving piston 42, after the first driving part 40 completes the linear movement of the stator can 20 in the first direction, the second driving part 50 enables the stator can 20 to rotate in the second direction. The above-described embodiment, which rotatably couples the stator housing 20, facilitates the movement of the stator housing 20 in the second direction, stabilizes the movement, and improves the designability, workability, and assemblability of the variable displacement pump.
The magnetic memory metal of the above embodiment as the power source of the driving body 54 has the advantages that: on one hand, the strength of the magnetic induction lines and the deformation function of the magnetic effect metal are in one-to-one correspondence, and the current passing through the coil and the strength of the magnetic induction lines generated by the electromagnet 53 are also in one-to-one correspondence, so that the current and the deformation of the deformation body 52 are in one-to-one correspondence, and therefore, the displacement generated by the driving body 54 is more accurate, and further, the position which can be reached by the driving body 54 through the movement of the first sliding shoe 55 driving the stator sleeve 20 in the second direction is more accurate, and the adjustment of the eccentricity in the second direction is more accurate; on the other hand, the deformation sensitivity and frequency of the magnetic effect metal are higher than those of the mechanical driving displacement and the hydraulic driving displacement after being influenced by the magnetic induction line, which makes the adjustment sensitivity of the eccentricity in the second direction higher.
The advantage of using first and second shoes 55, 516 to directly drive stator can 20 to rotate in the second direction in the above embodiments is: the head of the first slipper 55 and the head of the second slipper 516 are matched with the outer peripheral surface of the stator sleeve 20, and the tails of the first slipper 55 and the second slipper 516 are connected in a hinged manner, so that after the stator sleeve 20 rotates around the connection for a certain angle, as shown in fig. 12, 14, 15 and 18, the first slipper 55 and the second slipper 516 can still be closely attached to the stator sleeve 20, and the stability of the stator sleeve 20 in the rotating process in the first direction and the stability after the rotation are improved.
In a preferred embodiment of the present invention, as shown in fig. 12 and 14, a first sliding groove 21 is formed on an outer periphery of the stator sleeve 20 corresponding to the first sliding shoe 55, a groove bottom of the first sliding groove 21 is processed into an arc-shaped surface with a high surface quality, and a head of the first sliding shoe 55 is attached to the groove bottom of the first sliding groove 21 to reduce the sliding resistance of the first sliding shoe 55; the second sliding groove 22 is formed in the periphery of the stator sleeve 20 corresponding to the second sliding shoe 516, so that the groove bottom of the second sliding groove 22 is processed into an arc-shaped surface with high surface precision, and the head of the second sliding shoe 516 is attached to the groove bottom of the second sliding groove 22, so as to reduce the sliding resistance of the second sliding shoe 516.
In a preferred embodiment of the present invention, as shown in fig. 1, a protrusion 4111 is disposed at a head of the first balance piston 411, a third sliding slot 24 is disposed on an outer circumference of the stator sleeve 20 corresponding to the first balance piston 411, and a recess 25 is disposed at a bottom of the third sliding slot 24, when the second driving part 50 does not drive the stator sleeve 20, the protrusion 4111 is embedded in the recess 25, so that when the second driving part 50 does not drive the stator sleeve 20, the recess 25 has a certain limiting effect on the protrusion 4111, so that when the first driving part 40 drives the stator sleeve 20, the stator sleeve 20 can stably move in the first direction without play in a non-first direction. When the stator housing 20 is driven by the second driving part 50, as shown in fig. 18, the protrusion 4111 slides out of the recess 25, and the recess 25 contacts the restriction of the protrusion 4111.
In a preferred embodiment of the present invention, as shown in fig. 7 and 10, the outer peripheral surface of the pivot 23 has at least a partial cylindrical surface having the same diameter as the outer peripheral surface of the driving piston 42, wherein: when the first driving unit moves linearly in the first direction, the pivot 23 is at least partially located in the left guide chamber during the initial stroke of the first direction movement. In the present embodiment, the initial stroke section is understood to be a moving stroke of the stator can 20 in the first direction before the position to be driven by the second driving portion 50 is not reached. Thus, when the eccentricity is adjusted only by adjusting in the first direction, the pivot portion 23 is at least partially located in the left guide cavity, so as to limit the rotation of the stator sleeve 20, thereby further effectively preventing the stator sleeve 20 from shifting in the non-first direction.
It should be noted that: as shown in fig. 6 and 9, when the variable displacement pump is started from a state where the eccentricity is 0 (at this time, the variable displacement pump is mostly used as a supplementary oil pump), the initial eccentricity is obtained by driving the stator can 20 in the first direction by the first driving part 40.
In a preferred embodiment of the present invention, as shown in fig. 15 and 18, the driving body 54 is disposed in the first bushing, the second balance piston 515 is disposed in the second bushing 514, and both the first bushing 514 and the second bushing 58 are made of titanium alloy having high strength and rigidity. The effect of setting up the great bush of intensity and rigidity lies in: when the first and second shoes 55 and 516 drive the stator sleeve 20 to rotate in the second direction, the first and second shoes 55 and 516 generate a larger component force in the radial direction, and the high-strength and high-rigidity bushing prevents the component force from damaging the related components of the second drive group and the second balance group 51.
In a preferred embodiment of the present invention, as shown in fig. 15 and 18, the rear portions of the first and second shoes 55 and 516 are each provided in a ball head structure, and the first and second shoes 55 and 516 are connected to the driving body 54 and the second balance piston 515 through the first and second pressing covers, respectively.
The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the scope of the present invention is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present invention, and such modifications and equivalents should also be considered as falling within the scope of the present invention.