Double-motion-freedom-degree piston pump core and piston pump

Abstract

The piston pump core comprises a transmission mechanism, an upper connection lining, a cylinder body, a lower connection lining and a small idler wheel, the transmission mechanism comprises a transmission shaft, balls, an upper connection piston guide rail and a lower connection piston guide rail, one end of the transmission shaft is provided with an external spline connected with a motor main shaft, and four rows of V-shaped grooves are formed in the middle of the transmission shaft; comprising two rows of V-shaped grooves close to an external spline end and two rows of V-shaped grooves far away from the external spline end, balls in the two rows of V-shaped grooves close to the external spline end are matched with an upper connection piston guide rail, balls in the two rows of V-shaped grooves far away from the external spline end are matched with a lower connection piston guide rail, and a double-face cam is arranged in the middle of the piston guide rails. The small rollers are respectively matched with the small rollers on the two sides to realize rotation and reciprocating motion; u-shaped grooves are formed in the two ends of the upper connection piston guide rail and matched with the upper connection lining and the cylinder body respectively to form a closed containing cavity, and the reciprocating motion of the piston enables the size of the closed containing cavity to change so as to achieve oil suction and discharge. U-shaped grooves in the two ends of the upper connection piston guide rail are provided with oil distribution ports in the radial direction, and the oil distribution ports are matched with oil distribution ports formed in the upper connection lining and the cylinder body respectively, so that the oil distribution function is achieved.

Description

Technical Field

[0001] This invention belongs to the field of fluid machinery technology, and in particular to a piston pump core and piston pump with two degrees of freedom of motion. Background Technology

[0002] A pump is an energy conversion device that converts mechanical energy into fluid pressure energy, typically used to output high-pressure fluids. Traditional pumps, such as piston, vane, gear, and screw pumps, rely primarily on sliding friction in their mechanical structure during operation, resulting in significant frictional energy loss. Furthermore, their components have complex shapes and high manufacturing costs.

[0003] The dual-degree-of-freedom piston pump integrates the shaft and piston into a single design, utilizing the piston's "circumferential rotation + axial reciprocating" dual-degree-of-freedom motion principle to achieve continuous oil suction and discharge, eliminating the need for the distributor plate structure in traditional piston pumps. Simultaneously, a symmetrical cam roller structure replaces the sliding shoe swashplate structure, transforming the original sliding friction pair into rolling friction. Furthermore, the symmetrical force-bearing structure ensures that the piston experiences no radial force, eliminating the two friction pairs between the piston and cylinder, and between the cylinder and distributor plate. This results in higher pump efficiency and overcomes the limitations imposed by sliding friction pairs on pump performance.

[0004] Centrifugal pumps, gear pumps, and screw pumps achieve oil suction and discharge by changing the volume of the cavity through the rotational motion of vanes, gears, and screws, respectively. This rotational motion can be directly obtained from a power source such as an electric motor, without any conversion to other motion forms. Traditional piston pumps achieve oil suction and discharge by changing the cavity volume through the reciprocating motion of the piston. This reciprocating motion is converted from rotation to reciprocating motion through a swashplate and slipper structure. During the conversion from rotation to reciprocating motion, the cylinder only rotates at high speed, while the swashplate remains fixed. The radial tilting force generated during the conversion from rotation to reciprocating motion is supported by the oil film between the piston and the cylinder. Dual-degree-of-freedom piston pumps integrate rotation and reciprocating motion in the piston, relying on the ball bearings between the drive shaft and the piston to achieve torque transmission from rotation to reciprocating motion. However, the excessive number of arc grooves and ball bearing mating points can cause over-positioning, which is detrimental to transmission stability. Summary of the Invention

[0005] The present invention aims to solve at least one of the technical problems existing in the prior art.

[0006] Therefore, the present invention provides a piston pump core and piston pump with two degrees of freedom of motion.

[0007] The technical solution of the present invention is as follows:

[0008] According to one aspect, a dual-degree-of-freedom piston pump core is provided, comprising a transmission mechanism, an upper bushing, a cylinder, a lower bushing, and small rollers. The transmission mechanism includes a transmission shaft, balls, an upper piston guide rail, and a lower piston guide rail. One end of the transmission shaft has an external spline connecting to a motor spindle, and the middle has four rows of V-grooves, including two rows of V-grooves near the external spline and two rows of V-grooves away from the external spline. The balls in the two rows of V-grooves near the external spline engage with the upper piston guide rail, and the balls in the two rows of V-grooves away from the external spline engage with the lower piston guide rail. The piston guide rail has a double-sided cam in the middle, which cooperates with small rollers on both sides to achieve rotation and reciprocating motion. The upper piston guide rail has U-shaped grooves at both ends, which cooperate with the upper bushing and cylinder to form a closed cavity. The reciprocating motion of the piston causes the volume of the closed cavity to change, thereby achieving oil suction and discharge. The upper piston guide rail has oil distribution ports radially opened in the U-shaped grooves at both ends, which cooperate with the oil distribution ports on the upper bushing and cylinder to achieve the oil distribution function. The lower piston guide rail has the same structure and function as the upper piston guide rail, but the circumferential direction of the guide rail surfaces of the two differs by 45°.

[0009] Furthermore, the pair of V-grooves furthest from the external spline end forms a 90° angle with the pair of V-grooves closest to the external spline side.

[0010] Furthermore, the piston guide rail has two symmetrical V-shaped grooves inside, which respectively cooperate with the balls in the V-shaped groove of the drive shaft to realize the transmission of torque.

[0011] Furthermore, limit holes are provided at both ends of each V-groove to install limit pins to limit the extreme positions of the balls.

[0012] Furthermore, the piston pump core also includes a cylinder block bracket and a small roller bracket. The cylinder block bracket has a cylinder block mounting hole in the middle for mounting the cylinder block; two square high-pressure ports are symmetrically opened in the radial direction for high-pressure oil to flow out; there are two brackets at each end, namely an upper bracket and a lower bracket. Each bracket has two roller bracket mounting holes for mounting four small roller brackets; there is a stud on the top of each bracket for fixing the upper bushing and the lower bushing, respectively.

[0013] Furthermore, the small roller bracket has bracket mounting holes on its circumference. The small roller bracket is fixed to the roller bracket mounting holes on the cylinder block bracket by small roller bracket pins. The two small roller mounting holes are used to install small rollers.

[0014] Furthermore, the cylinder body has a through hole in the middle and the upper and lower outer circular surfaces mate with the U-shaped grooves of the upper and lower piston guide rails, respectively, to form a closed cavity; the largest outer circular surface mates with the cylinder mounting hole of the cylinder body bracket; the high-pressure square hole communicates with the square high-pressure port on the cylinder body bracket to output high-pressure oil to the outside. During the rotation of the piston guide rail, the low-pressure distribution port opened on it and the upper and lower oil distribution square holes on the cylinder body open and close regularly to realize the distribution function of the pump core.

[0015] Furthermore, the inner bore and outer circular surface of the upper bushing mate with the side of the U-shaped groove of the piston guide rail to form a closed cavity. The end face has an oblong hole that communicates with the distribution square hole to allow fuel to pass through. The radially opened distribution square hole and the distribution square hole on the piston guide rail are regularly switched to achieve the distribution function.

[0016] Furthermore, the upper bushing is fixed to the stud on the cylinder block bracket through the mounting hole on the mounting plate.

[0017] According to another aspect, a dual-degree-of-freedom piston pump is provided, which includes the aforementioned dual-degree-of-freedom piston pump core.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0019] (1) The present invention opens a V-shaped groove in the transmission shaft and piston guide rail, which reduces the number of mating points of the existing arc groove and ball, avoiding over-positioning caused by too many mating points of the arc groove and ball, and is conducive to smooth transmission.

[0020] (2) The present invention opens a V-shaped groove in the transmission shaft and piston guide rail, which reduces the number of mating points of the existing circular arc groove and ball, avoids assembly interference caused by machining errors and small mating clearances, and is beneficial to the assembly of pump core.

[0021] (3) The present invention opens a V-shaped groove in the transmission shaft and piston guide rail, which reduces the processing difficulty compared with the existing circular arc groove and helps to reduce the processing cost of the parts.

[0022] (4) The present invention enables the piston pump to achieve better flow distribution function and achieve stable output flow by cooperating with the transmission mechanism, upper bushing, cylinder, lower bushing and small roller. Attached Figure Description

[0023] The accompanying drawings, which form part of this specification, are provided to further illustrate embodiments of the invention and, together with the textual description, explain the principles of the invention. It is obvious that the drawings described below are merely some embodiments of the invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0024] Figure 1 This is a schematic diagram of a V-groove transmission mechanism and a piston pump core with dual degrees of freedom of motion according to the present invention.

[0025] Figure 2 This is a schematic diagram of the external appearance of the drive shaft with V-groove of the present invention;

[0026] Figure 3 This is a schematic cross-sectional view of the transmission shaft with V-groove of the present invention;

[0027] Figure 4 This is a schematic diagram of the external structure of the lower piston guide rail of the present invention;

[0028] Figure 5 This is a schematic diagram of the V-groove of the lower piston guide rail of the present invention;

[0029] Figure 6 This is a schematic diagram of the cross-section of the lower piston guide rail of the present invention;

[0030] Figure 7 This is a schematic diagram of the pump cylinder support structure of the present invention;

[0031] Figure 8 This is a schematic diagram of the cylinder block structure of the present invention;

[0032] Figure 9 This is a schematic diagram of the small roller support structure of the present invention;

[0033] Figure 10 This is a schematic diagram of the upper bushing structure of the present invention. Detailed Implementation

[0034] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0037] like Figure 1-10 As shown, the present invention provides a piston pump core with two degrees of freedom of motion, including a drive shaft 1, a limiting pin 2, a ball bearing 3, a lower piston guide rail 4, a small roller 5, a cylinder support 6, a cylinder 7, an upper piston guide rail 8, a small roller support 9, an upper bushing 10, a bearing 11, an upper cover plate 12, a small roller support pin 13, a lower bushing 14, and a lower cover plate 15.

[0038] The structure of the drive shaft 1 is as follows Figure 2 , Figure 3 As shown, one end is connected to the motor spindle via an external spline 101, and bearings 11 are installed at the journals 102 on both sides to support the rotation of the drive shaft 1. Four rows of V-grooves are formed in the middle, including two rows of V-grooves 103 and 107 near the external spline 101, two rows of V-grooves 105 away from the external spline, and a corresponding row. The ball bearings 3 in the two rows of V-grooves near the external spline 101 engage with the upper piston guide rail 8, and the ball bearings 3 in the two rows of V-grooves away from the external spline engage with the lower piston guide rail 4.

[0039] The structure of the lower piston guide rail 4 is as follows: Figure 4 , Figure 5 , Figure 6As shown, there are upper U-shaped grooves 401 and lower U-shaped grooves 402 at both ends, and a double-sided cam 403 in the middle. There are four high-pressure distribution ports 404 on the outside of the U-shaped grooves and four low-pressure distribution ports 405 on the inside. There are two V-shaped grooves 406 in the middle through hole to cooperate with the ball 3 to realize the functions of torque transmission and reciprocating motion.

[0040] The structure of the cylinder block support 6 is as follows: Figure 7 As shown, a cylinder mounting hole 601 is opened in the middle for mounting the cylinder 7; two square high-pressure ports 603 are symmetrically opened in the radial direction for high-pressure oil to flow out; there are two brackets at each end, namely upper bracket 608 and lower bracket 604, and each bracket has two roller bracket mounting holes 605 for mounting four small roller brackets 9; there is a stud 606 on the top of each bracket for fixing the upper bushing 10 and the lower bushing 13 respectively.

[0041] The structure of the cylinder block 7 is as follows: Figure 8 As shown, a through hole 705 in the middle and upper outer circular surfaces 703 and lower outer circular surfaces 708 respectively mate with the U-shaped grooves of the upper piston guide rail 8 and lower piston guide rail 4 to form a closed cavity. The largest outer circular surface 701 mates with the cylinder mounting hole 601 of the cylinder block bracket 6. The high-pressure square hole 707 connects to the square high-pressure port 603 on the cylinder block bracket 6 to output high-pressure oil to the outside. During the rotation of the piston guide rail, the low-pressure distribution port 405 opened on it and the oil distribution square holes 706 and 709 on the cylinder block 7 open and close regularly to realize the distribution function of the pump core.

[0042] The structure of the small roller bracket 9 is as follows: Figure 9 As shown, each of its circumferences has bracket mounting holes 902. The small roller bracket 9 is fixed to the roller bracket mounting holes 605 on the cylinder block bracket 6 by the small roller bracket pin 13. The two small roller mounting holes 901 are used to install the small roller 5.

[0043] The structure of the upper bushing 10 is as follows: Figure 10 As shown, its inner bore surface 1001 and outer circular surface 1003 mate with the side of the U-shaped groove of the piston guide rail to form a closed cavity. An oblong hole 1002 is opened on the end face, communicating with the distribution square hole 1006 to allow fuel to pass through. The radially opened distribution square hole 1006 regularly switches with the distribution square hole opened on the piston guide rail to achieve the distribution function. The upper bushing 10 is fixed to the stud 606 on the cylinder block bracket 6 through the mounting hole 1005 on the mounting flat 1004.

[0044] In other words, this invention features V-shaped grooves within the drive shaft and piston guide rail, reducing the number of mating points between the piston and ball bearings compared to existing circular arc grooves. This avoids over-positioning caused by excessive mating points between the circular arc grooves and ball bearings, thus promoting smooth transmission. The V-shaped grooves within the drive shaft and piston guide rail also reduce the number of mating points compared to existing circular arc grooves, preventing assembly interference caused by machining errors and small clearances, which is beneficial for pump core assembly. Furthermore, the V-shaped grooves within the drive shaft and piston guide rail reduce machining difficulty compared to existing circular arc grooves, thus lowering component manufacturing costs. Through the coordinated operation of the transmission mechanism, upper bushing, cylinder body, lower bushing, and small rollers, this invention enables the piston pump to achieve better flow distribution and a stable output flow rate.

[0045] According to another embodiment, a dual-degree-of-freedom piston pump is provided, which includes the dual-degree-of-freedom piston pump core of the above embodiment.

[0046] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0047] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0048] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A piston pump core with two degrees of freedom of motion, characterized in that, The piston pump core includes a transmission mechanism, an upper bushing, a cylinder, a lower bushing, and small rollers. The transmission mechanism includes a transmission shaft, balls, an upper piston guide rail, and a lower piston guide rail. One end of the transmission shaft has an external spline connecting to the motor spindle, and the middle has four rows of V-grooves, including two rows near the external spline and two rows away from the external spline. The balls in the two rows of V-grooves near the external spline engage with the upper piston guide rail, and the balls in the two rows of V-grooves away from the external spline engage with the lower piston guide rail. The piston guide rail has a... A double-sided cam engages with small rollers on both sides to achieve rotation and reciprocating motion. The upper piston guide rail has U-shaped grooves at both ends, which engage with the upper bushing and cylinder to form a closed cavity. The reciprocating motion of the piston causes the volume of this closed cavity to change, thereby achieving oil suction and discharge. The U-shaped grooves at both ends of the upper piston guide rail have radially opened oil distribution ports, which engage with the oil distribution ports on the upper bushing and cylinder to achieve the oil distribution function. The lower piston guide rail has the same structure and function as the upper piston guide rail, but the circumferential direction of the two guide rail surfaces differs by 45°.

2. The piston pump core with two degrees of freedom of motion according to claim 1, characterized in that, The pair of V-grooves furthest from the external spline end are at 90° to the pair of V-grooves closest to the external spline side.

3. The piston pump core with two degrees of freedom of motion according to claim 2, characterized in that, The piston guide rail has two symmetrical V-shaped grooves inside, which cooperate with the balls in the V-shaped groove of the drive shaft to transmit torque.

4. A piston pump core with two degrees of freedom of motion according to claim 2 or 3, characterized in that, Each V-groove has limit holes at both ends for installing limit pins to limit the extreme positions of the balls.

5. A piston pump core with two degrees of freedom of motion according to any one of claims 1-4, characterized in that, The piston pump core also includes a cylinder block bracket and a small roller bracket. The cylinder block bracket has a cylinder block mounting hole in the middle for mounting the cylinder block; two square high-pressure ports are symmetrically opened in the radial direction for high-pressure oil to flow out; there are two brackets at each end, namely an upper bracket and a lower bracket. Each bracket has two roller bracket mounting holes for mounting four small roller brackets; there is a stud on the top of each bracket for fixing the upper bushing and the lower bushing, respectively.

6. The piston pump core with two degrees of freedom of motion according to claim 5, characterized in that, The small roller bracket has mounting holes on its circumference. The small roller bracket is fixed to the roller bracket mounting holes on the cylinder block bracket by small roller bracket pins. The two small roller mounting holes are used to install small rollers.

7. The piston pump core with two degrees of freedom of motion according to claim 5, characterized in that, The cylinder body has a through hole in the middle and the upper and lower outer circular surfaces mate with the U-shaped grooves of the upper and lower piston guide rails, respectively, to form a closed cavity; the largest outer circular surface mates with the cylinder mounting hole of the cylinder body bracket; the high-pressure square hole connects to the square high-pressure port on the cylinder body bracket to output high-pressure oil to the outside. During the rotation of the piston guide rail, the low-pressure distribution port opened on it and the upper and lower oil distribution square holes on the cylinder body open and close regularly to realize the distribution function of the pump core.

8. The piston pump core with two degrees of freedom of motion according to claim 1, characterized in that, The inner and outer circular surfaces of the upper bushing mate with the U-shaped groove side of the piston guide rail to form a closed cavity. The end face has an oblong hole that communicates with the distribution square hole to allow fuel to pass through. The radially opened distribution square hole and the distribution square hole on the piston guide rail open regularly to realize the distribution function.

9. A piston pump core with two degrees of freedom of motion according to claim 8, characterized in that, The upper bushing is fixed to the stud on the cylinder block bracket through the mounting hole on the mounting plate.

10. A piston pump with two degrees of freedom of motion, characterized in that, The piston pump includes the dual-degree-of-freedom piston pump core as described in any one of claims 1-9.

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