Integrated servo motor pump based on center spherical hinge pump structure

Abstract

An integrated servo motor pump based on a center spherical hinge pump structure is characterized in that a plunger pump assembly adopts a center spherical hinge return stroke mechanism and is composed of a center spherical hinge, a chuck, an ejector pin and the like, and compared with a fixed gap type return stroke structure, the center spherical hinge return stroke mechanism is simple; a cylinder body center spring provides pre-tightening force, and the pre-tightening force is transmitted to a center spherical hinge through an ejector pin and then acts on a chuck to press a sliding shoe to a swash plate, and it is ensured that the sliding shoe is not disengaged from the swash plate. Cooling oil is introduced through an external system, and the whole internal elements of the whole motor pump are cooled; the end face of the oil distributing disc is provided with a system cooling oil guiding oil way inlet, so that the cooling oil way inlet, a cooling oil return port and a high-low pressure oil port are located on the same plane of the oil distributing disc, and meanwhile a sealing structure is arranged in the radial direction to seal oil in a cavity.

Description

Technical Field

[0001] The invention relates to an integrated servo motor pump based on a central ball joint pump structure, belonging to the technical field of electric drive hydraulic systems. Background Art

[0002] Servo motor pumps are the core key products of the emerging electric static (hydraulic) actuator system (EHA, Electro-Hydraulic Actuators), which is equivalent to simplifying the traditional three products of "motor, hydraulic pump, servo valve" into one, with the functions of "power, energy conversion, control", etc., and directly converting adjustable electricity into controllable flow. Due to the elimination of the valve control link, while retaining the advantages of the hydraulic system such as strong heavy-duty capacity, electrification is achieved, throttling losses are eliminated, the design is greatly simplified, energy consumption is reduced by 80%, reliability is improved by an order of magnitude, and the full life cycle cost is significantly reduced.

[0003] The servo motor pumps in the prior art are mostly designed and spliced ​​by splitting the servo motor and the hydraulic pump. There are also integrated designs that integrate the stator, rotor and rotor of the servo motor and the rotor of the hydraulic pump with the same axis, shell and flow field. However, the return mechanism of the pump assembly adopts a fixed gap return structure. Chinese patent ZL202110679550.0 is a highly integrated oil-liquid internal circulation servo motor pump, involving sleeves, pressure plates, adjustment rings and other structural parts. The advantage is that it can achieve precise gap positioning and achieve higher speeds. The disadvantage is that the structure is complex and the machining precision requirements are high. In terms of internal cooling of the product, there is no circulating cooling structure achieved by introducing external oil from the system.

[0004] Chinese patent 202311233043.X is a plug-in servo motor pump, whose plunger return mechanism is also a fixed-gap return structure. The structure is relatively complex, but the thin shell can be plugged into the whole machine, achieving lightweight and miniaturization of the overall design, suitable for compact mechanisms. In addition, the product structure does not have a design for circulating cooling of the motor and internal oil channels. Similarly, in terms of internal cooling of the product, there is no circulating cooling structure by introducing external oil from the system.

[0005] Chinese patent ZL201920315489.X discloses a plunger pump with a lubricable transmission shaft structure, in which a ball joint structure is involved. A ball joint and a ball joint spring are provided on the end face of the return plate away from the swinging end. The ball joint and the return plate are in contact with an arc surface, and the machining process is somewhat difficult. In addition, the ball joint provides preload through the ball joint spring instead of the cylinder center spring, which is more complicated in structure. Summary of the invention

[0006] The technical problem to be solved by the present invention is: to overcome the complexity of the existing fixed-gap return structure and provide an integrated servo motor pump based on a central ball joint pump structure. The pump structure is simple and compact, suitable for the characteristics of industrial applications, can realize energy conversion and at the same time has the characteristics of highly integrated output control.

[0007] The purpose of the present invention is achieved through the following technical solutions:

[0008] An integrated servo motor pump based on a central ball-jointed pump structure comprises a central ball-jointed plunger pump assembly, a servo motor assembly, a housing, and a main shaft;

[0009] The central ball-jointed plunger pump assembly and the servo motor assembly share a housing and a main shaft; the servo motor assembly is located in the left cavity of the housing, and the ball-jointed plunger pump assembly is located in the right cavity of the housing;

[0010] The center ball hinge type plunger pump assembly is mainly composed of a bimetallic cylinder, a plunger assembly, a slant plate, a chuck, a center ball hinge, an ejector pin, a sleeve, a center spring, a spring seat, and an oil distribution plate. The center ball hinge type plunger pump assembly is fixed and restrained by a sleeve. The sleeve is located in the right cavity of the housing and fits with the inner wall of the cavity to support the entire center ball hinge type plunger pump assembly.

[0011] The spring force generated by the compression of the center spring acts on one side of the spring seat, while the other side of the spring seat acts on the ejector pin, and the force is transmitted to the end face of the center ball joint through the ejector pin. The spherical surface of the center ball joint contacts the conical surface of the center hole of the chuck, and finally the force is applied to the chuck, and the bottom surface of the sliding shoe of the plunger assembly is pressed against the inclined plate through the chuck; in addition, the pre-compression force of the center spring makes the bottom surface of the bimetallic cylinder body press against the oil separator; the center ball joint and the main shaft are connected by splines and rotate synchronously.

[0012] Compared with the prior art, the present invention has the following beneficial effects:

[0013] (1) The present invention adopts a central ball-jointed pump structure to replace the fixed-gap pump return structure in the prior art, reducing the number of structural parts and connecting parts by 50%; the central ball-jointed pump structure adopted in the present invention has better machining processability, greatly reducing the machining zero-degree accuracy requirements caused by the gap structure, and is more suitable for large-scale production.

[0014] (2) The present invention can introduce cooling oil from an external system to cool the entire internal components of the entire motor pump; the cooling oil circuit inlet, cooling oil return port, and high and low pressure oil ports are located on the same oil distribution plate plane.

[0015] (3) The cooling oil inlet and oil return port as well as the high and low pressure oil ports of the servo motor pump in the present invention are coplanar, which reduces the system side installation positioning accuracy compared with the existing radial seal installation structure, and is easy to install and use.

[0016] (4) The flange installation structure is easier to use and maintain than the plug-in installation structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a cross-sectional view of the servo motor pump housing.

[0018] Figure 2 It is a ball joint return mechanism.

[0019] Figure 3 This is the structural diagram of the center ball joint.

[0020] Figure 4 This is the right side view of the servo motor pump.

[0021] Figure 5 This is a cross-sectional view of the servo motor pump cooling oil channel.

[0022] Figure 6 This is the oil separator seal structure diagram. DETAILED DESCRIPTION

[0023] To make the objectives, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0024] An integrated servo motor pump based on a central ball joint pump structure, the overall idea is:

[0025] (1) The plunger pump assembly adopts a center ball joint return mechanism, which consists of a center ball joint, a chuck, an ejector pin, etc., which is simpler than the fixed gap return structure;

[0026] (2) The cylinder center spring provides preload, which is transmitted to the center ball joint through the ejector pin and then acts on the chuck, pressing the sliding shoe against the swash plate to ensure that the sliding shoe does not disengage from the swash plate;

[0027] (3) Introducing cooling oil through an external system to cool the entire internal components of the motor pump;

[0028] (4) The end surface of the oil distributor is provided with an inlet for the system cooling oil guide circuit, so that the cooling oil circuit inlet, cooling oil return port, and high and low pressure oil ports are located on the same plane of the oil distributor. At the same time, a sealing structure is provided radially to achieve sealing of the oil inside the cavity.

[0029] More specific:

[0030] like Figure 1 As shown, it mainly includes a central ball-jointed plunger pump assembly 2, a servo motor assembly 1, a housing 3, and a main shaft 4. The central ball-jointed plunger pump assembly 2 and the servo motor assembly 1 share a housing 3 and a main shaft 4. The servo motor assembly 1 is located in the left cavity of the housing 3, and the ball-jointed plunger pump assembly 2 is located in the right cavity of the housing 3.

[0031] like Figure 1 As shown, the center ball hinge type plunger pump assembly is mainly composed of a bimetallic cylinder 2-4, a plunger assembly 2-5, a swash plate 2-6, a chuck 2-2, a center ball hinge 2-1, a pin 2-3, a sleeve 2-7, a center spring 2-8 and a spring seat 2-9. The center ball hinge type plunger pump assembly is fixed and constrained by the sleeve 2-7. The sleeve 2-7 is located in the right cavity of the housing 3 and fits against the inner wall of the cavity to support the entire center ball hinge type plunger pump assembly 2.

[0032] The spring force generated by the compression of the center spring 2-8 acts on one side of the spring seat 2-9, and the other side of the spring seat 2-9 acts on the ejector pin 2-3, and the force is transmitted to the end face of the center ball joint 2-1 through the ejector pin 2-3. The spherical surface of the center ball joint contacts the conical surface of the center hole of the chuck 2-2, and finally the force is applied to the chuck 2-2, and the bottom surface of the sliding shoe of the plunger assembly 2-5 is pressed against the inclined plate 2-6 through the chuck. On the other side, the pre-tightening force of the center spring 2-8 makes the bottom surface of the bimetallic cylinder body 2-4 press against the oil distribution plate 2-10. The center ball joint 2-1 is connected to the main shaft 4 through a spline and rotates synchronously.

[0033] The servo motor assembly transmits the electromagnetically generated torque to the bimetallic cylinder 2-4 through the main shaft 4, driving the bimetallic cylinder to rotate, thereby realizing the normal operation of the plunger pump.

[0034] like Figure 2 As shown in the figure, the ball-jointed plunger pump adopts a center ball-jointed return structure. Figure 3 The figure shows the structure diagram of the center ball joint.

[0035] like Figure 4 As shown, a high (low) pressure oil port 2-11 and a low (high) pressure oil port 2-12 are provided on the end face of the oil separator 2-10, which are used for the inlet and outlet of the servo motor pump suction and discharge oil, as well as a cooling oil circuit inlet 2-14 and a cooling oil return port 2-13. These four oil ports are all located on the same plane of the oil separator 2-10. In addition, a light hole 3-1 is provided through the flange of the housing 3, which is connected to the external system with screws for easy installation, maintenance and use.

[0036] like Figure 4 and Figure 5 As shown, external cooling oil flows in from the cooling oil circuit inlet 2-14 on the end face of the oil separator 2-10, connects with the cooling oil channel 2-15 opened in the oil separator and the channel 3-2 opened in the shell 3, and the cooling oil enters the left cavity of the shell 3. After cooling the servo motor assembly, the oil enters the right cavity through the channel 3-3 on the shell 3 and flows back to the system through the return oil port 2-13 on the oil separator 2-10.

[0037] like Figure 6As shown, the oil separator is provided with radial sealing grooves 2-17 to seal the oil inside the cavity; the end face high (low) pressure oil port 2-11 and the low (high) oil port 2-12 are provided with end face sealing grooves 2-18 on the outside, and the cooling oil inlet 2-14 and the cooling oil return port 2-13 are provided with end face sealing grooves 2-19 on the outside to achieve the sealing connection between each oil port and the external system. The oil separator 2-10 is fixed to the housing 3 by a clamping ring 2-16.

[0038] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

[0039] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. An integrated servo motor pump based on a central ball joint pump structure, characterized in that: It comprises a central ball-jointed plunger pump assembly (2), a servo motor assembly (1), a housing (3), and a main shaft (4); The central ball-jointed plunger pump assembly (2) and the servo motor assembly (1) share a housing (3) and a main shaft (4); the servo motor assembly (1) is located in a cavity on the left side of the housing (3), and the ball-jointed plunger pump assembly (2) is located in a cavity on the right side of the housing (3); The center ball hinge type plunger pump assembly (2) mainly consists of a bimetallic cylinder body (2-4), a plunger assembly (2-5), a slant plate (2-6), a chuck (2-2), a center ball hinge (2-1), a thimble (2-3), a sleeve (2-7), a center spring (2-8), a spring seat (2-9), and an oil distribution plate (2-10). The center ball hinge type plunger pump assembly (2) is fixed and restrained by the sleeve (2-7). The sleeve (2-7) is located in the right cavity of the housing (3) and fits with the inner wall of the cavity to support the entire center ball hinge type plunger pump assembly (2). The spring force generated by the compression of the center spring (2-8) acts on one side of the spring seat (2-9), while the other side of the spring seat (2-9) acts on the ejector pin (2-3), and the force is transmitted to the end face of the center ball joint (2-1) through the ejector pin (2-3). The spherical surface of the center ball joint (2-1) contacts the conical surface of the center hole of the chuck (2-2), and finally the force is applied to the chuck (2-2), and the bottom surface of the sliding shoe of the plunger assembly (2-5) is pressed against the inclined plate (2-6) through the chuck (2-2); in addition, the bottom surface of the bimetallic cylinder body (2-4) is pressed against the oil distribution plate (2-10) through the pre-compression force of the center spring (2-8); the center ball joint (2-1) and the main shaft (4) are connected by a spline and rotate synchronously.

2. The integrated servo motor pump based on the central ball joint pump structure according to claim 1 is characterized in that: The servo motor assembly (1) transmits the rotational torque generated by the electromagnetic to the bimetallic cylinder (2-4) through the main shaft (4), drives the bimetallic cylinder (2-4) to rotate, and realizes the normal operation of the plunger pump.

3. The integrated servo motor pump based on the central ball joint pump structure according to claim 1 is characterized in that: The end surface of the oil separator (2-10) is provided with a first oil port and a second oil port, which are used for the inlet and outlet of the servo motor pump oil suction and discharge, as well as a cooling oil circuit inlet (2-14) and a cooling oil return port (2-13). The four oil ports are all located on the same plane of the oil separator (2-10). In addition, a light hole (3-1) is provided through the flange of the housing (3) and connected to the external system in the form of screws, which is convenient for installation, maintenance and use.

4. The integrated servo motor pump based on the central ball joint pump structure according to claim 3 is characterized in that: External cooling oil flows in from the cooling oil passage inlet (2-14) on the end face of the oil separator (2-10), connects with the cooling oil passage (2-15) opened in the oil separator (2-10) and the hole (3-2) opened in the housing (3), and the cooling oil enters the left cavity of the housing (3), cools the servo motor assembly (1), and then the oil enters the right cavity through the hole (3-3) on the housing (3), and flows back to the system through the oil return port (2-13) on the oil separator (2-10).

5. The integrated servo motor pump based on the central ball joint pump structure according to claim 1 is characterized in that: The oil separation plate (2-10) is provided with a radial sealing groove (2-17) to achieve sealing of the oil inside the cavity.

6. The integrated servo motor pump based on the central ball joint pump structure according to claim 3 is characterized in that: End face sealing grooves (2-18) are formed on the outside of the first oil port and the second oil port, and end face sealing grooves (2-19) are formed on the outside of the cooling oil circuit inlet (2-14) and the cooling oil return port (2-13), so as to realize sealed connection between each oil port and an external system.

7. The integrated servo motor pump based on the central ball joint pump structure according to claim 1 is characterized in that: The oil separation plate (2-10) is fixed to the housing (3) via a clamping ring (2-16).

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