Bidirectional high-pressure linear conjugate internal gear pump and static pressure supporting groove slotting method thereof

Abstract

The invention provides a bidirectional high-pressure linear conjugate internal gear pump and a static pressure supporting groove slotting method thereof. The device comprises an upper shell and a lower shell, wherein an upper shell oil hole, an upper shell shaft hole and an upper shell end face hole are formed in the upper shell; the upper shell oil hole is used for introducing oil into the upper shell side surface oil hole; the upper shell shaft hole is used for mounting a first transmission shaft; an upper shell end face hole is used for installing a bearing and a front end cover to complete sealing of an upper shell element; the lower shell is provided with a lower shell oil hole, a lower shell seat hole, a static pressure supporting groove and a lower shell end face hole. The lower shell oil hole is used for introducing oil into the lower shell side surface oil hole; the lower shell seat hole is used for mounting an outer gear ring; the lower shell seat hole is provided with an arc-shaped convex crescent plate; the lower shell end face hole is used for installing a rear end cover to complete sealing of a lower shell element; the end face of the upper shell and the end face of the lower shell are sealed through an O-shaped sealing ring. And a positioning pin is arranged between the end surfaces of the upper shell and the lower shell for fixed connection. The invention further provides a grooving method of the static pressure supporting groove.

Description

Technical Field

[0001] The invention relates to the technical field of hydraulic transmission, in particular to a bidirectional high-pressure linear conjugate internal gear pump and a method for opening a static pressure support groove thereof. Background Art

[0002] The volumetric speed control system is one of the most ideal solutions to meet the requirements of low-speed heavy load, high-precision control and high reliability of hydraulic systems. The closed volumetric speed control system gets rid of the heavy oil tank and part of the cooling system, improves the power-to-weight ratio and anti-pollution ability of the system, and is widely used in military industry, metallurgy, engineering machinery, medical chemical industry and other industries.

[0003] The hydraulic pump is the main power element in the hydraulic system, which converts mechanical energy into hydraulic energy of the working medium for output. The closed volumetric speed control system requires the gear pump to have bidirectional high-pressure capability, which places higher requirements on the hydraulic pump. The gear pump is a hydraulic pump widely used in hydraulic systems. Its compact structure, small size, and unique oil suction and discharge structure make it have better sealing effect, lower environmental noise, smaller flow pulsation, and higher oil suction capacity. It is a potential hydraulic pump that can be used in the closed volumetric speed control system.

[0004] For a linear conjugate internal gear pump, its core component is a pair of gears and a gear ring that mesh with each other using linear conjugate tooth shapes in the pump body. The meshing gears and gear rings are divided into two closed chambers by a crescent plate. The rotation of the internal gear drives the gear ring to rotate in the same direction. During the movement, the closed chamber changes in area to complete the oil suction and discharge action. In the actual application of the closed volume servo speed control system, according to the working conditions, the linear conjugate internal gear pump needs to complete the high and low pressure oil ports and rotation direction switching. Due to the high-speed rotation of the gear ring and the unbalanced radial force generated by the oil pressure difference caused by the change in direction, the lubricating oil film between the gear ring and the seat hole is unstable, and friction bonding is prone to occur, causing severe heat generation and increased matching clearance, increased leakage, and decreased volumetric efficiency. Summary of the invention

[0005] In response to the above defects or improvement needs of the prior art, the present invention provides a bidirectional high-pressure linear conjugate internal gear pump that can be used for a closed volumetric servo speed control system, which can fully realize the bidirectional high- and low-pressure switching required for four-quadrant operation of the closed volumetric servo speed control system, and ensure the volumetric efficiency of the gear pump, while improving the low-speed and heavy-load capacity of the gear pump quadrant, extending the service life of the internal gear pump, and ensuring the stable operation of the internal gear pump in the four quadrants.

[0006] The technical means adopted by the present invention are as follows:

[0007] A bidirectional high-pressure linear conjugate internal gear pump comprises: an upper housing and a lower housing, wherein:

[0008] The upper shell is provided with an upper shell oil hole, an upper shell shaft hole and an upper shell end hole; the upper shell oil hole is used to introduce oil into the upper shell side oil hole; the upper shell shaft hole is used to install the first transmission shaft; the upper shell end hole is used to install the bearing and the front end cover to complete the sealing of the upper shell components;

[0009] The lower shell is provided with a lower shell oil hole, a lower shell seat hole, a static pressure support groove and a lower shell end hole; the lower shell oil hole is used to introduce oil into the lower shell side oil hole; the lower shell seat hole is used to install the outer gear ring; the lower shell seat hole has an arc-shaped raised crescent plate; the lower shell end hole is used to install the rear end cover to complete the sealing of the lower shell components;

[0010] The upper shell and the lower shell end faces are sealed by an O-ring; and positioning pins are installed between the upper shell and the lower shell end faces for fixed connection.

[0011] Furthermore, the outer gear ring is meshed with the inner gear shaft through a linear conjugate tooth shape; the inner wall surface of the outer gear ring abuts against the outer arc surface of the crescent plate; the outer wall of the inner gear shaft abuts against the inner arc surface of the crescent plate, realizing internal meshing transmission action.

[0012] Furthermore, there is a fixed gap between the outer wall of the outer gear ring and the inner wall of the lower shell seat hole, and the upper shell oil hole and the lower shell oil hole introduce oil into the axisymmetric static pressure support groove in the fixed gap, and the static pressure support groove is used to match the eccentric unbalanced radial force caused by the fixed center distance.

[0013] Furthermore, one end of the internal gear shaft is installed in the seat hole of the lower shell, and the other end is connected to the first transmission shaft through a spline; a bearing and a C-shaped shaft clamp spring are installed on the first transmission shaft; the first transmission shaft extends through the front end cover to connect other components.

[0014] The present invention also includes a method for cutting a static pressure support groove in a bidirectional high-pressure linear conjugate internal gear pump, the specific steps of which include:

[0015] S1. Solve the unbalanced radial force under four-quadrant working conditions for the closed pump control requirements of the linear conjugate internal gear pump;

[0016] S2. Solve the imbalance at each stage of the meshing process under time variation;

[0017] S3, vector collection of unbalanced radial forces under different meshing processes;

[0018] S4. The eccentric area and the static pressure support groove opening area S are obtained by the magnitude and direction of the unbalanced radial force vector;

[0019] S5. Solve the support groove opening angle θ, opening width h, opening depression angle γ, and opening depth Δl through the static pressure support groove area S;

[0020] S6. Complete the optimal static pressure support groove shape design to meet the requirements of two-way high pressure four-quadrant working conditions.

[0021] Furthermore, the step S1 specifically includes:

[0022] The unbalanced radial force includes meshing eccentric force and oil pressure differential eccentric force, and the meshing eccentric force and oil pressure differential eccentric force are respectively solved and then fitted into the unbalanced radial force;

[0023] S11. Solve the meshing eccentric force:

[0024]

[0025] Among them, F qt is the meshing tangential force; F qr is the radial force of meshing; F q is the meshing force; T is the meshing transmission torque; α is the pitch circle pressure angle;

[0026] S12, solve the eccentric force of oil hydraulic pressure difference:

[0027]

[0028] Among them, F Px F is the x-direction component of the oil pressure differential; Py F is the y-direction component of the oil pressure difference; p is the resultant eccentric force of the oil pressure difference; B is the tooth width of the outer gear ring; r a is the root circle radius of the outer gear ring; P is the system working pressure; is the sum of the wrap angles of the transition section between the low-pressure chamber and the high- and low-pressure chambers of the outer gear ring; It is the wrap angle of the section where the outer gear ring contacts the low-pressure chamber.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The bidirectional high-pressure linear conjugate internal gear pump and the static pressure support groove opening method provided by the present invention have a structure that improves the first pump quadrant limit working condition of the hydraulic pump element. The low-speed heavy-load capacity of the first quadrant is improved by using the structure of the present invention.

[0031] The bidirectional high-pressure linear conjugate internal gear pump and the static pressure support groove opening method provided by the present invention can complete the four-quadrant working conditions required by closed pump control, that is, the high and low pressure direction switching of different rotation directions under pump working conditions, and the high and low pressure direction switching of different rotation directions under motor working conditions.

[0032] The bidirectional high-pressure linear conjugate internal gear pump and the static pressure support groove opening method thereof provided by the present invention can achieve volumetric efficiency under four-quadrant working conditions to meet the requirements of a closed volume servo speed regulation system.

[0033] Based on the above reasons, the present invention can be widely promoted in the field of hydraulic transmission technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0035] Figure 1 The figure is a diagram showing the structure and working principle of the bidirectional high-pressure linear conjugate internal gear pump in the present invention.

[0036] Figure 2 It is the principle diagram of the motion engagement in the present invention.

[0037] Figure 3 This is a flow chart of the principle of static pressure support groove opening in the present invention.

[0038] Figure 4 It is a three-dimensional structural diagram of the static pressure support groove in the present invention.

[0039] Figure 5 It is a diagram of the four-quadrant operation and specific implementation effect of the closed pump control system in the present invention.

[0040] Figure 6 It is a pressure-speed-volumetric efficiency diagram for a closed pump control system in an embodiment of the present invention.

[0041] In the figure: 1. front end cover; 2. first transmission shaft; 3. bearing; 4. shaft clamp spring; 5. upper housing; 6. oil hole of upper housing; 7. internal gear shaft; 8. external gear ring; 9. O-ring; 10. positioning pin; 11. lower housing; 12. rear end cover; 13. static pressure support groove; 14. crescent plate; 15. oil hole of lower housing. DETAILED DESCRIPTION

[0042] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0044] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0045] Unless otherwise specifically stated, the relative arrangement of the parts and steps described in these embodiments, the numerical expressions and numerical values ​​do not limit the scope of the present invention. At the same time, it should be clear that, for ease of description, the sizes of the various parts shown in the drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to ordinary technicians in the relevant field may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be regarded as part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further discussed in subsequent drawings.

[0046] In the description of the present invention, it is necessary to understand that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction. Therefore, they cannot be understood as limiting the scope of protection of the present invention: the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0047] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below their position devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0048] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. If not otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0049] like Figure 1 As shown, the present invention provides a bidirectional high-pressure linear conjugate internal gear pump, comprising: an upper housing 5 and a lower housing 11, wherein:

[0050] The upper shell 5 is provided with an upper shell oil hole 6, an upper shell shaft hole and an upper shell end hole; the upper shell oil hole 6 is used to introduce oil into the upper shell side oil hole; the upper shell shaft hole is used to install the first transmission shaft 2; the upper shell end hole is used to install the bearing 3 and the front end cover 1, completing the sealing of the upper shell components;

[0051] The lower shell 11 is provided with a lower shell oil hole 15, a lower shell seat hole, a static pressure support groove 13 and a lower shell end hole; the lower shell oil hole 15 is used to introduce oil into the lower shell side oil hole; the lower shell seat hole is used to install the outer gear ring 8; the lower shell seat hole has an arc-shaped raised crescent plate 14; the lower shell end hole is used to install the rear end cover 12 to complete the sealing of the lower shell components;

[0052] The upper shell 5 and the lower shell 11 are sealed by an O-ring 9 ; and positioning pins 10 are installed between the end surfaces of the upper shell 5 and the lower shell 11 for fixed connection.

[0053] In specific implementation, as a preferred embodiment of the present invention, the outer gear ring 8 meshes with the inner gear shaft 7 through a linear conjugate tooth shape; the inner wall surface of the outer gear ring 8 abuts against the outer arc surface of the crescent plate 14; the outer wall of the inner gear shaft 7 abuts against the inner arc surface of the crescent plate 14 to achieve meshing action.

[0054] During implementation, the internal gear shaft 7 and the external gear ring 8 ensure a fixed center distance.

[0055] When specifically implemented, as a preferred embodiment of the present invention, Figure 2 As shown, there is a fixed gap between the outer wall of the outer gear ring 8 and the inner wall of the lower housing seat hole, and the upper housing oil hole 6 and the lower housing oil hole 15 introduce oil into the axisymmetric static pressure support groove 13 in the fixed gap, and the static pressure support groove 13 is used to match the eccentric unbalanced radial force caused by the fixed center distance.

[0056] In specific implementation, as a preferred embodiment of the present invention, one end of the internal gear shaft 7 is installed in the seat hole of the lower shell, and the other end is connected to the first transmission shaft 2 through a spline; the first transmission shaft 2 is installed with a bearing 3 and a C-type shaft clamp spring 4; the first transmission shaft 2 extends through the front end cover 1 to connect other components.

[0057] like Figure 3 As shown, the present invention also includes a method for cutting a static pressure support groove in a bidirectional high-pressure linear conjugate internal gear pump, and the specific steps include:

[0058] S1. Solve the unbalanced radial force under four-quadrant working conditions for the closed pump control requirements of the linear conjugate internal gear pump;

[0059] In specific implementation, as a preferred embodiment of the present invention, the step S1 specifically includes:

[0060] The unbalanced radial force includes meshing eccentric force and oil pressure differential eccentric force, and the meshing eccentric force and oil pressure differential eccentric force are respectively solved and then fitted into the unbalanced radial force;

[0061] S11. Solve the meshing eccentric force:

[0062]

[0063] Among them, F qt is the meshing tangential force; F qr is the radial force of meshing; F q is the meshing force; T is the meshing transmission torque; α is the pitch circle pressure angle;

[0064] S12, solve the eccentric force of oil hydraulic pressure difference:

[0065]

[0066] Among them, F Px F is the x-direction component of the oil pressure differential; Py F is the y-direction component of the oil pressure difference; p is the resultant eccentric force of the oil pressure difference; B is the tooth width of the outer gear ring; r ais the root circle radius of the outer gear ring; P is the system working pressure; is the sum of the wrap angles of the transition section between the low-pressure chamber and the high- and low-pressure chambers of the outer gear ring; It is the wrap angle of the section where the outer gear ring contacts the low-pressure chamber.

[0067] S2. Solve the imbalance at each stage of the meshing process under time variation;

[0068] S3, vector collection of unbalanced radial forces under different meshing processes;

[0069] S4. The eccentric area and the static pressure support groove opening area S are obtained by the magnitude and direction of the unbalanced radial force vector;

[0070] S5. Solve the support groove opening angle θ, opening width h, opening depression angle γ, and opening depth Δl through the static pressure support groove area S;

[0071] During implementation, the volumetric efficiency requirements and mechanical efficiency requirements of the closed pump control four-quadrant operation are used as the boundary conditions for the parameters of step S5;

[0072] S6. Complete the optimal static pressure support groove shape design to meet the requirements of two-way high pressure four-quadrant working conditions.

[0073] Example

[0074] like Figure 1 As shown, the present invention provides a bidirectional high-pressure linear conjugate internal gear pump and a method for opening a static pressure support groove thereof. In this embodiment, Figure 4 The three-dimensional structure diagram of the special structure static pressure support groove of the present invention. Figure 3 The special structure static pressure support groove grooving principle flow chart of the present invention designs the optimal static pressure support groove grooving shape, opens the inner wall of the lower shell seat hole, forms a special static pressure support area between the lower shell seat hole and the outer wall of the outer gear ring 8, and introduces oil from the upper shell oil hole 6 and the lower shell oil hole 15 to complete the four-quadrant operation required by the closed volume servo speed control system.

[0075] Figure 5 This is a diagram showing the four-quadrant operation and specific implementation effect of the present invention in a closed pump control system; Figure 6 is a pressure-speed-volume efficiency diagram for a closed pump control system in an embodiment of the present invention; wherein n min To achieve the minimum speed of the gear pump under the system pressure, n min ^' is the minimum speed under the system pressure required by the present invention in practical application. Figure 5 and Figure 6It can be seen that the linear conjugate internal gear pump of the present invention, which can be used in a closed volume servo speed control system, can work under the four-quadrant working conditions required by the closed volume servo speed control system, can ensure the high and low pressure switching under the change of rotation direction in the pump control system, and at the same time improve the low-speed heavy-load capacity of the first pump quadrant. In actual applications, the volumetric efficiency of the tested element can reach a maximum of 98.14% and a minimum of 77.05% at system pressures of 3 to 7MPa and operating speeds of -200 to -1600rpm, respectively, meeting the volumetric efficiency requirements of the closed volume servo speed control system for the hydraulic pump.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A bidirectional high-pressure linear conjugate internal gear pump, characterized in that: include: An upper shell (5) and a lower shell (11), wherein: The upper shell (5) is provided with an upper shell oil hole (6), an upper shell shaft hole and an upper shell end hole; the upper shell oil hole (6) is used to introduce oil from the upper shell side oil hole; the upper shell shaft hole is used to install the first transmission shaft (2); the upper shell end hole is used to install the bearing (3) and the front end cover (1), so as to complete the sealing of the upper shell components; The lower shell (11) is provided with a lower shell oil hole (15), a lower shell seat hole, a static pressure support groove (13) and a lower shell end hole; the lower shell oil hole (15) is used to introduce oil from the lower shell side oil hole; The seat hole of the lower shell is used to install the outer gear ring (8); the seat hole of the lower shell has an arc-shaped raised crescent plate (14); the end hole of the lower shell is used to install the rear end cover (12) to complete the sealing of the lower shell components; The end surfaces of the upper shell (5) and the lower shell (11) are sealed by an O-ring (9); and positioning pins (10) are installed between the end surfaces of the upper shell (5) and the lower shell (11) for fixed connection.

2. The bidirectional high-pressure linear conjugate internal gear pump according to claim 1, characterized in that: The outer gear ring (8) meshes with the inner gear shaft (7) through a linear conjugate tooth profile; the inner wall surface of the outer gear ring (8) abuts against the outer arc surface of the crescent plate (14); the outer wall of the inner gear shaft (7) abuts against the inner arc surface of the crescent plate (14), thereby realizing an internal meshing transmission action.

3. The bidirectional high-pressure linear conjugate internal gear pump according to claim 1, characterized in that: A fixed gap exists between the outer wall of the outer gear ring (8) and the inner wall of the seat hole of the lower housing, and the oil hole (6) of the upper housing and the oil hole (15) of the lower housing introduce oil into the axisymmetric static pressure support groove (13) in the fixed gap. The static pressure support groove (13) is used to match the eccentric unbalanced radial force caused by the fixed center distance.

4. The bidirectional high-pressure linear conjugate internal gear pump according to claim 2, characterized in that: One end of the internal gear shaft (7) is installed in the seat hole of the lower shell body, and the other end is connected to the first transmission shaft (2) through a spline; a bearing (3) and a C-shaped shaft clamp spring (4) are installed on the first transmission shaft (2); the first transmission shaft (2) extends through the front end cover (1) to connect with other components.

5. A method for cutting a static pressure support groove in a bidirectional high-pressure linear conjugate internal gear pump, characterized in that: The specific steps include: S1. Solve the unbalanced radial force under four-quadrant working conditions for the closed pump control requirements of the linear conjugate internal gear pump; S2. Solve the imbalance at each stage of the meshing process under time variation; S3, vector collection of unbalanced radial forces under different meshing processes; S4. The eccentric area and the static pressure support groove opening area S are obtained by the magnitude and direction of the unbalanced radial force vector; S5. Solve the support groove opening angle θ, opening width h, opening depression angle γ, and opening depth Δl through the static pressure support groove area S; S6. Complete the optimal static pressure support groove shape design to meet the requirements of two-way high pressure four-quadrant working conditions.

6. The method for cutting a static pressure support groove in a bidirectional high-pressure linear conjugate internal gear pump according to claim 5, characterized in that: The step S1 specifically includes: The unbalanced radial force includes meshing eccentric force and oil pressure differential eccentric force, and the meshing eccentric force and oil pressure differential eccentric force are respectively solved and then fitted into the unbalanced radial force; S11. Solve the meshing eccentric force: Among them, F qt is the meshing tangential force; F qr is the radial force of meshing; F q is the meshing force; T is the meshing transmission torque; α is the pitch circle pressure angle; S12, solve the eccentric force of oil hydraulic pressure difference: Among them, F Px F is the x-direction component of the oil pressure differential; Py F is the y-direction component of the oil pressure differential; p is the resultant eccentric force of the oil pressure difference; B is the tooth width of the outer gear ring; r a is the root circle radius of the outer gear ring; P is the system working pressure; is the sum of the wrap angles of the transition sections between the low-pressure chamber and the high- and low-pressure chambers of the outer gear ring; It is the wrap angle of the section where the outer gear ring contacts the low-pressure chamber.

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