A cartridge-type servo motor pump

Abstract

A cartridge-type servo motor pump includes a thin housing and functional components installed inside. The thin housing is divided into left and right chambers. The left chamber houses a motor stator assembly, a component mounting base, a pump assembly, and a planar distribution plate, wherein the pump assembly and the planar distribution plate are both installed inside the component mounting base, which is located on the left side of the motor stator assembly. The right chamber houses a rotary transformer and an electrical connector, with the rotary transformer stator and electrical connector mounted on the thin housing. A shaft passes through both the left and right chambers, and the rotary transformer rotor is mounted on the shaft in the right chamber. In the left chamber, from left to right, the pump assembly, a first bearing, a rotor assembly, and a second bearing are sequentially mounted on the shaft. The shaft directly drives the planar pump cylinder in the pump assembly to rotate, forming a pair of high-speed rotating planar friction pairs with the fixed planar distribution plate. This invention balances integration and convenience: the components are integrated into a circular thin-shell structure for easy individual testing, and can also be integrally cartridge-mounted into the whole machine to achieve lightweight and miniaturized overall design.

Description

Technical Field

[0001] This invention relates to a cartridge-type servo motor pump, belonging to the technical field of electrically driven hydraulic systems. Background Technology

[0002] Servo motor pumps are a core component of emerging electro-hydraulic actuators (EHAs). They essentially simplify the traditional three components—motor, hydraulic pump, and servo valve—into a single unit, combining power generation, energy conversion, and control functions. This directly converts adjustable electrical power into controllable flow. By eliminating the valve control component, they achieve electrification while retaining the advantages of hydraulic systems, such as high load-bearing capacity. This eliminates throttling losses, significantly simplifies design, reduces energy consumption by 80%, improves reliability by an order of magnitude, and significantly lowers life-cycle costs.

[0003] Currently, most servo motor pumps on the market are designed and assembled from separate servo motors and hydraulic pumps. There are also integrated designs that combine the stator and rotor of the servo motor and the rotor of the hydraulic pump, making them coaxial, share a common housing, and have a common flow field. However, there are two ways to use them:

[0004] First, the entire servo motor pump is connected to the flange of the whole machine, or is exposed in whole or in part. The servo motor pump of this type has a semi-embedded plug-in structure. The external mounting flange is fastened to the actuation system with screws. The advantage is that the product can be debugged separately. The disadvantage is that the integration with the whole machine is not enough and the size and weight are relatively large.

[0005] Secondly, the components of the servo motor pump are sequentially installed in a hole in the whole machine, such as in patent ZL201910559987.3 "A High-Compact Electrostatic Actuator for Robot Joints". This type of servo motor pump does not have an independent housing. Its advantage is that it is fully integrated with the whole machine, but it loses the independence of the servo motor pump product, cannot be tested separately, and is not convenient for production. Summary of the Invention

[0006] The technical problem solved by the present invention is to overcome the shortcomings of the prior art and provide a cartridge servo motor pump. The servo motor pump is composed of a circular thin shell and components such as a permanent magnet synchronous servo motor and a bidirectional quantitative plunger pump core installed inside it, while taking into account both integration and convenience.

[0007] The technical solution of this invention is:

[0008] A cartridge-type servo motor pump includes: a thin housing, a motor assembly, an assembly mounting base, a pump assembly, a planar distribution plate, a shaft, a rotary transformer, and an electrical connector; the motor assembly includes a stator assembly and a rotor assembly; the rotary transformer includes a resolver stator and a resolver rotor.

[0009] The thin shell is divided into left and right cavities. The left cavity houses the motor stator assembly, the assembly mounting base, the pump assembly, and the planar distribution plate. The pump assembly and the planar distribution plate are both installed inside the assembly mounting base, which is located on the left side of the motor stator assembly.

[0010] A rotary transformer and an electrical connector are installed inside the right cavity; the rotary transformer stator and the electrical connector are mounted on a thin-walled housing.

[0011] The shaft extends axially through the left and right cavities. In the right cavity, the resolver rotor is mounted on the shaft. In the left cavity, from left to right, the pump assembly, the first bearing, the rotor assembly, and the second bearing are sequentially mounted on the shaft.

[0012] The shaft directly drives the flat pump cylinder in the pump assembly to rotate, forming a pair of high-speed rotating planar friction pairs with the fixed planar distribution plate.

[0013] Furthermore, the pump assembly includes a plunger return mechanism, a flat pump cylinder, and a plunger assembly;

[0014] The plunger assembly is installed into the plunger cavity of the flat pump cylinder body. The plunger assembly and the flat pump cylinder body are installed together inside the plunger return mechanism to form the pump assembly.

[0015] Furthermore, the rotary transformer also includes resolver leads; the resolver leads are drawn from the resolver stator, and the resolver rotor is installed inside the resolver stator, with the two having a concentric structure.

[0016] Furthermore, within the left cavity, the component mounting base and the thin shell are assembled with a transition tolerance fit to ensure coaxiality; the planar distribution plate is installed in the component mounting base with a clearance tolerance fit to facilitate disassembly and assembly; the motor stator assembly and the thin shell are fitted with an interference tolerance fit and secured with screws to prevent them from separating; the motor rotor assembly and the shaft are fitted with an interference tolerance fit to prevent relative rotation between them.

[0017] Furthermore, a semi-circular groove is formed on the outer cylindrical surface of the component mounting base, and circumferential positioning is achieved after the second cylindrical pin is installed; a threaded hole is formed in the radial direction on the outer cylindrical surface of the component mounting base, and axial positioning of the component mounting base is achieved by installing screws.

[0018] Furthermore, a semi-circular groove is provided on the planar distribution plate, and a third cylindrical pin is installed to prevent the planar distribution plate from rotating relative to the component mounting base.

[0019] Furthermore, the servo motor pump is installed in the hole of the whole device in the form of a plug-in. The thin shell and the whole device are assembled with clearance fit, which facilitates the disassembly and assembly of the servo motor pump. After the servo motor pump is installed in the hole of the whole device in the form of a plug-in, the support cylinder and the cover plate are installed in sequence, and the axial limit of the servo motor pump is realized by axial compression.

[0020] Furthermore, the contact surfaces of the distribution plate and the whole unit are designed with circular oil inlet and outlet ports that are matched one-to-one; sealing grooves are opened on the oil inlet and outlet ports of the distribution plate, and an axial seal is formed after the third sealing ring is installed.

[0021] Furthermore, a sealing groove is opened on the thin shell. After the first sealing ring is installed, a radial seal is formed to seal the low-pressure oil and achieve zero leakage to the outside. The electrical connector is fixed to the right cavity end of the thin shell with screws. After the second sealing ring is installed, a radial seal is formed. The non-sealed side of the electrical connector has a threaded hole for installing disassembly and assembly tools.

[0022] Furthermore, the connection between the electrical connector and the thin shell is not limited to a uniform cross-section design. If the diameter of the electrical connector is much smaller than the diameter of the thin shell, the right end of the thin shell is designed as a stepped shape, and the electrical connector is installed on the part with the smaller diameter.

[0023] Furthermore, the motor assembly also includes motor leads;

[0024] A rectangular hole perpendicular to the axis and extending tangentially is opened on the thin shell to form a radial space, providing space for the installation of motor leads.

[0025] Furthermore, a semi-circular groove is opened on the outer cylindrical surface of the thin shell, and the circumferential limit of the servo motor pump is realized by installing the first cylindrical pin.

[0026] The advantages of this invention compared to the prior art are:

[0027] (1) The servo motor pump of the present invention is designed with a circular thin shell, and the frameless servo motor, plunger pump and rotary transformer are mounted on a shaft and then the whole is put into this circular thin shell; the components are integrated into a circular thin shell structure, which is convenient for individual testing; at the same time, they can be inserted into the whole machine, realizing the lightweight and miniaturization of the overall design.

[0028] (2) The circular thin shell of the servo motor pump of the present invention is designed with through holes, which facilitates the installation of frameless servo motors, plunger pumps and rotary transformers, and is also easy to manufacture and process.

[0029] (3) The housing and the whole machine are fitted with clearance. The housing is designed with grooves. After the cylindrical pin is installed, circumferential positioning is achieved to prevent relative rotation.

[0030] (4) This invention designs a planar pump cylinder body and a planar distribution plate to form a planar distribution structure, which makes it easier to process and repair high-speed rotating friction pairs. Circular inlet and outlet ports are designed on the contact surfaces of the planar distribution plate and the entire machine for transmitting hydraulic oil. Sealing grooves are opened on the inlet and outlet ports of the distribution plate, and after installing sealing rings, an axial seal is formed, reliably sealing the hydraulic oil;

[0031] (5) This invention designs a support cylinder and a cover plate, and uses the connecting screws between the cover plate and the whole machine to axially limit the servo motor pump, so that the pump cylinder body, the distribution plate and the entire motor pump and the whole machine are tightly fitted together. In addition, the electrical connector has screw holes, which facilitates the insertion or removal of the motor pump as a whole after installing the disassembly tools;

[0032] (6) The present invention provides space for motor lead installation by opening a rectangular hole on the housing that is perpendicular to the axis and extends in the tangential direction. Attached Figure Description

[0033] Figure 1 A schematic diagram of the basic components of a cartridge-type servo motor pump;

[0034] Figure 2 This is a schematic diagram of a servo motor pump.

[0035] Figure 3 View of servo motor pump B;

[0036] Figure 4 A schematic diagram of the component mounting bracket installation;

[0037] Figure 5 A schematic diagram of the installation of a planar distribution plate;

[0038] Figure 6 A schematic diagram of the motor stator assembly installation;

[0039] Figure 7 A schematic diagram showing the installation of the motor pump and the complete unit;

[0040] Among them, 1-thin shell, 2-motor assembly, 3-assembly mounting base, 4-pump assembly (plunger return mechanism 4.1, flat pump cylinder 4.2, plunger assembly 4.3), 5-flat distribution plate, 6-shaft, 7-rotor transformer (rotor stator 7.1, rotor 7.2, lead wire 7.3), 8-electrical connector, 9-support cylinder, 10-cover plate, 11-cylindrical pin (11.1, 11.2, 11.3), 12-screw (12.1, 12.2, 12.3, 12.4), 13-sealing ring (13.1, 13.2, 13.3), 14-bearing (14.1, 14.2). Detailed Implementation

[0041] The specific embodiments of the present invention will now be described in further detail with reference to the accompanying drawings.

[0042] This invention proposes a cartridge-type servo motor pump that combines integration and convenience: the components are integrated into a circular thin-shell structure for easy individual testing; at the same time, they can be inserted into the whole machine, achieving lightweight and miniaturized overall design.

[0043] The cartridge-type servo motor pump of this invention specifically includes: a thin housing 1, a motor assembly 2 (stator assembly 2.1, rotor assembly 2.2, motor leads 2.3), an assembly mounting base 3, a pump assembly 4 (plunger return mechanism 4.1, flat pump cylinder 4.2, plunger assembly 4.3), a flat distribution plate 5, a shaft 6, a rotary transformer 7 (rotor stator 7.1, rotor 7.2, leads 7.3), an electrical connector 8, a support cylinder 9, a cover plate 10, cylindrical pins 11 (11.1, 11.2, 11.3), screws 12 (12.1, 12.2, 12.3, 12.4), sealing rings 13 (13.1, 13.2, 13.3), and bearings 14 (14.1, 14.2). See [link to other components]. Figures 1 to 7 As shown.

[0044] like Figure 1 , 2 As shown in Figure 3, all components of the servo motor pump are integrated into a thin housing 1. The housing 1 can be divided into left and right chambers. The left chamber houses the motor stator assembly 2.1, the assembly mounting base 3, the pump assembly 4, and the planar distribution plate 5. The pump assembly 4 and the planar distribution plate 5 are both installed inside the assembly mounting base 3, which is located to the left of the motor stator assembly 2.1. The right chamber houses the rotary transformer 7 and the electrical connector 8. The rotary transformer stator 7.1 and the electrical connector 8 are mounted on the thin housing 1.

[0045] Shaft 6 extends axially through the left and right cavities. In the right cavity, the resolver rotor 7.2 is mounted on shaft 6. In the left cavity, from left to right, pump assembly 4, first bearing 14.1, rotor assembly 2.2, and second bearing 14.2 are sequentially mounted on shaft 6. Shaft 6 directly drives the planar pump cylinder 4.2 in pump assembly 4 to rotate, forming a pair of high-speed rotating planar friction pairs with the fixed planar distribution plate 5.

[0046] Pump assembly 4 includes a plunger return mechanism 4.1, a flat pump cylinder body 4.2, and a plunger assembly 4.3;

[0047] The plunger assembly 4.3 is installed into the plunger cavity of the flat pump cylinder 4.2. The plunger assembly 4.3 and the flat pump cylinder 4.2 are installed together inside the plunger return mechanism 4.1 to form the pump assembly 4.

[0048] Furthermore, the rotary transformer 7 also includes a resolver lead 7.3; the resolver lead 7.3 is led out from the resolver stator 7.1, and the resolver rotor 7.2 is installed inside the resolver stator 7.1, and the two are in a concentric structure.

[0049] like Figure 4 As shown in (1), in the left cavity, the component mounting base 3 and the housing 1 are assembled with a transition tolerance fit to ensure coaxiality. A semi-circular groove is formed on the outer cylindrical surface of the component mounting base 3; after installing the cylindrical pin 11.2, circumferential positioning is achieved. For example... Figure 4As shown in (2), a threaded hole is opened in the radial direction of the outer cylindrical surface of the component mounting base 3. After installing two screws 12.1, the axial positioning of the component mounting base 3 is achieved.

[0050] like Figure 5 As shown in (1), the planar distribution plate 5 is installed in the component mounting base 3 with a clearance tolerance fit, which facilitates disassembly and assembly. The planar distribution plate 5 has a semi-circular groove, which prevents it from rotating relative to the component mounting base 3 after the cylindrical pin 11.3 is installed. The shaft 6 directly drives the planar pump cylinder 4.2 to rotate, forming a pair of high-speed rotating planar friction pairs with the fixed planar distribution plate 5.

[0051] like Figure 5 As shown in (2), the contact surfaces of the distribution plate 5 and the whole machine are designed with circular oil inlets and outlets, and the oil inlets are connected one by one. A sealing groove is opened on the oil inlet and outlet of the distribution plate 5, and after the sealing ring 13.3 is installed, an axial seal is formed to reliably seal the hydraulic oil.

[0052] like Figure 6 As shown, the motor stator assembly 2.1 and the housing 1 are fitted with an interference fit and secured with three screws 12.2, providing double-layer protection to prevent them from separating. The motor rotor assembly 2.2 and the shaft 6 are fitted with an interference fit to prevent relative rotation between them.

[0053] In the right cavity, such as Figure 1 , 2 As shown in Figure 3, a sealing groove is formed on the housing 1. After installing the sealing ring 13.1, a radial seal is formed, reliably sealing the low-pressure oil and achieving zero leakage to the outside. The electrical connector 8 is fixed to the housing 1 with screws 12.3. After installing the sealing ring 13.2, a radial seal is formed, serving as a sealing cover. A rectangular hole perpendicular to the axis and extending tangentially is formed on the housing 1, creating a radial space to provide installation space for the motor lead 2.3. In addition, the rectangular hole realizes the requirement of visual and transparent assembly of the motor lead 2.3, avoiding defects such as lead damage or breakage that may occur due to blind assembly. Figure 2 As shown, a semi-circular groove is formed on the outer cylindrical surface of the housing 1. After installing the cylindrical pin 11.1, the circumferential limit of the motor pump is achieved. Figure 3 As shown, the non-sealed side of the electrical connector 8 has a threaded hole for installing and removing tools, which facilitates the insertion and removal of the motor pump.

[0054] On the sealed side of the electrical connector 8, the motor lead 2.3 and the resolver lead 7.3 are respectively connected to the electrical connector.

[0055] Preferably, the connection between the electrical connector 8 and the thin shell 1 is not limited to a thin shell design with a uniform cross-section. If the diameter of the electrical connector 8 is significantly smaller than the diameter of the thin shell 1, the right end of the thin shell 1 may be designed as a stepped type, and the electrical connector 4 is installed on the part with the smaller diameter.

[0056] like Figure 7 As shown, the housing 1 and the complete unit are assembled with a clearance fit, which facilitates the disassembly and assembly of the motor pump. After the servo motor pump is installed in the hole of the complete unit in a plug-in form, the support cylinder 9, cover plate 10, and screws 12.4 are installed in sequence. The axial clamping method is used to achieve axial positioning of the motor pump. By calculating the dimensional chain, the oil distribution port between the pump cylinder 4.2, the distribution plate 5, and between the motor pump and the complete unit is made to fit tightly.

[0057] Example:

[0058] The cartridge-type servo motor pump proposed in this invention has advantages such as high integration, lightweight, miniaturization, and short processing cycle. Specifically, the axial fit length between the servo motor pump and the overall device is approximately 198mm, increasing the integration level of the motor pump by approximately 78.5%; reducing weight by approximately 20%; reducing volume by approximately 20.6%; and saving processing cycle by approximately 14.2%. It can be applied to aerospace servo systems with stringent requirements for size and weight.

[0059] Redundancy design has become an effective way to improve the reliability of EHA (Electronic Hydraulic Actuation). This makes it an important task to develop single-unit components that are space-saving, simple in shape, small in size, and easy to integrate without increasing system weight. The cartridge-type servo motor pump proposed in this invention has the advantages of being lightweight and miniaturized, and can be applied to aerospace servo systems with stringent requirements for size and weight, making it the first choice for highly integrated, redundant, and high-power EHA power units. In addition, it can also be extended to highly integrated aerospace hydraulic systems with strict size and weight requirements, intelligent robotics, and civilian industrial products.

[0060] The parts of this invention not described in detail are common knowledge to those skilled in the art.

Claims

1. A cartridge-type servo motor pump, characterized in that... include: A thin housing (1) and functional components installed inside it, the functional components including: a motor assembly (2), an assembly mounting base (3), a pump assembly (4), a planar distribution plate (5), a shaft (6), a rotary transformer (7), and an electrical connector (8); the motor assembly (2) includes a stator assembly (2.1) and a rotor assembly (2.2); the rotary transformer (7) includes a resolver stator (7.1) and a resolver rotor (7.2); The thin shell (1) is divided into left and right cavities. The left cavity is equipped with the motor stator assembly (2.1), the assembly mounting base (3), the pump assembly (4) and the flat distribution plate (5). The pump assembly (4) and the flat distribution plate (5) are both installed inside the assembly mounting base (3), which is installed on the left side of the motor stator assembly (2.1). A rotary transformer (7) and an electrical connector (8) are installed in the right cavity. The rotary transformer stator (7.1) and the electrical connector (8) are installed on the thin shell (1). Shaft (6) extends axially through the left and right cavities. In the right cavity, the resolver rotor (7.2) is mounted on shaft (6). In the left cavity, from left to right, pump assembly (4), first bearing (14.1), rotor assembly (2.2), and second bearing (14.2) are mounted on shaft (6) in sequence. The shaft (6) directly drives the flat pump cylinder (4.2) in the pump assembly (4) to rotate, forming a pair of high-speed rotating flat friction pairs with the fixed flat distribution plate (5); The servo motor pump is installed in the hole of the whole machine in the form of a plug-in. The thin shell (1) is assembled with the whole machine with clearance fit, which makes it easy to disassemble and assemble the servo motor pump. After the servo motor pump is installed in the hole of the whole machine in the form of a plug-in, the support cylinder (9) and the cover plate (10) are installed in sequence to achieve axial limit of the servo motor pump by axial pressing. The distribution plate (5) and the contact end face of the whole machine are designed with a pair of circular oil inlet and outlet ports; a sealing groove is opened on the oil inlet and outlet ports of the distribution plate (5), and an axial seal is formed after the third sealing ring (13.3) is installed; a sealing groove is opened on the thin shell (1), and a radial seal is formed after the first sealing ring (13.1) is installed to seal the low pressure oil and achieve zero leakage to the outside; the electrical connector (8) is fixed to the right cavity end of the thin shell (1) with screws, and a radial seal is formed after the second sealing ring (13.2) is installed. The thin shell (1) has a semi-circular groove on its outer cylindrical surface, and the servo motor pump is circumferentially limited by installing the first cylindrical pin (11.1).

2. The cartridge-type servo motor pump according to claim 1, characterized in that: The pump assembly (4) includes a plunger return mechanism (4.1), a flat pump cylinder (4.2), and a plunger assembly (4.3). The plunger assembly (4.3) is installed into the plunger cavity of the flat pump cylinder (4.2). The plunger assembly (4.3) and the flat pump cylinder (4.2) are installed together inside the plunger return mechanism (4.1) to form the pump assembly (4).

3. A cartridge-type servo motor pump according to claim 1, characterized in that: The rotary transformer (7) also includes a resolver lead (7.3); the resolver lead (7.3) is drawn from the resolver stator (7.1), and the resolver rotor (7.2) is installed inside the resolver stator (7.1), and the two are concentric.

4. A cartridge-type servo motor pump according to claim 1, characterized in that: Inside the left cavity, the component mounting base (3) and the thin shell (1) are assembled with a transition tolerance fit to ensure coaxiality; the planar distribution plate (5) is installed in the component mounting base (3) with a clearance tolerance fit to facilitate disassembly and assembly; the motor stator assembly (2.1) and the thin shell (1) are fitted with an interference tolerance fit and are tightened with screws to prevent them from separating; the motor rotor assembly (2.2) and the shaft (6) are fitted with an interference tolerance fit to prevent them from rotating relative to each other.

5. A cartridge-type servo motor pump according to claim 1, characterized in that: The component mounting base (3) has a semi-circular groove on its outer cylindrical surface. After the second cylindrical pin (11.2) is installed, the circumferential limit is achieved. The component mounting base (3) has a threaded hole in the radial direction on its outer cylindrical surface. The axial limit of the component mounting base (3) is achieved by installing screws.

6. A cartridge-type servo motor pump according to claim 1, characterized in that: The planar distribution plate (5) has a semi-circular groove, and the third cylindrical pin (11.3) is installed to prevent the planar distribution plate (5) from rotating relative to the component mounting base (3).

7. A cartridge-type servo motor pump according to claim 1, characterized in that: The electrical connector (8) has a threaded hole on the non-sealed side for installing and removing tools.

8. A cartridge-type servo motor pump according to claim 1, characterized in that: The connection between the electrical connector (8) and the thin shell (1) is not limited to a uniform cross-section design. If the diameter of the electrical connector (8) is much smaller than the diameter of the thin shell (1), the right end of the thin shell (1) is designed as a stepped type, and the electrical connector (8) is installed on the part with the smaller diameter.

9. A cartridge-type servo motor pump according to claim 1, characterized in that: The motor assembly (2) also includes motor leads (2.3); A rectangular hole perpendicular to the axis and extending in the tangential direction is opened on the thin shell (1) to form a radial space, providing installation space for the motor lead (2.3).

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