Hydrostatic support servo actuator and centrifuge

Abstract

The utility model discloses a kind of static pressure support servo actuators and centrifuges, it is related to static pressure support structure technical field, the static pressure support servo actuator includes: piston rod, is titanium alloy structural member;Front static pressure bearing, with piston rod clearance cooperation, front static pressure bearing is used to ensure the smooth movement of piston rod;Rear static pressure bearing, with piston rod clearance cooperation, rear static pressure bearing and front static pressure bearing cooperate to ensure the smooth movement of piston rod.The static pressure support servo actuator and centrifuge provided in the application, by selecting titanium alloy to make piston rod, front static pressure bearing and rear static pressure bearing can provide two-way static pressure support, ensure the stability and precision of piston rod in entire stroke, ensure that static pressure support servo actuator can stably, normally work in high g value test working condition.

Description

Technical Field

[0001] This utility model relates to the field of hydrostatic support structure technology, and more specifically, to a hydrostatic support servo actuator. Furthermore, this utility model also relates to a centrifuge including the aforementioned hydrostatic support servo actuator. Background Technology

[0002] In high-speed centrifuges and high-g aerospace testing conditions, actuators must withstand not only steady-state centrifugal accelerations of up to 100g, but also transient impacts from flight attitude maneuvers or rotor dynamic imbalances. Radial centrifugal forces can reach tens or even hundreds of kN. Traditional actuators use rolling bearings or polymer guide belts as supports, with a structural radial stiffness typically <100 N·μm⁻¹. Under enormous centrifugal loads, this results in eccentricities of tens or even hundreds of micrometers. Edge contact occurs between the piston rod and the seal, causing the coefficient of friction to increase sharply from 0.001 in the ideal static pressure range to over 0.1. Local temperature rises can reach over 80°C, leading to creep, extrusion, and tearing of the PTFE (Polytetrafluoroethylene) sealing ring, resulting in leakage and pressure holding failure. Experimental data show that after running continuously in a 100g centrifugal field for 30 minutes, the piston rod surface of the traditional servo cylinder has uneven wear grooves with a depth of 10–20μm, the coaxiality error expands to ISO (coaxiality tolerance grade) level 8 or above, the servo valve zero drift is >3%, and it cannot meet the amplitude accuracy requirements of high frequency sweep frequency test above 10Hz.

[0003] While conventional hydrostatic actuators convert friction pairs to full oil film lubrication, their hydrostatic chambers typically employ fixed orifices or capillary throttling, resulting in an oil film stiffness of only 20–40 N·μm⁻¹, far less than the lateral force gradient generated by centrifugal loads. When the centrifugal acceleration increases from 0 to 100g, the oil film thickness decreases by more than 60%, the damping coefficient drops by an order of magnitude, the system's open-loop gain decreases by 6dB, the phase lags by 30°, and the closed-loop bandwidth is compressed from 50Hz to less than 10Hz, making it impossible to achieve high dynamic response. Furthermore, fixed throttling is prone to "crushing" under low-speed, heavy-load conditions, and oil film instability induces self-excited vibrations at 100–300Hz, further exacerbating journal wear and high-frequency whistling from the servo valve.

[0004] In summary, improving the stability of hydrostatic support servo actuators to ensure their stable and normal operation under high-g test conditions is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a hydrostatic support servo actuator, in which the piston rod is made of titanium alloy, which improves stability and ensures that it can work stably and normally under high g-value test conditions.

[0006] Another objective of this invention is to provide a centrifuge that includes the aforementioned hydrostatic support servo actuator.

[0007] To achieve the above objectives, this utility model provides the following technical solution:

[0008] A hydrostatic support servo actuator, comprising:

[0009] The piston rod is a titanium alloy structural component;

[0010] A front hydrostatic bearing is fitted with the piston rod with a clearance, and the front hydrostatic bearing is used to ensure the smooth movement of the piston rod;

[0011] The rear hydrostatic bearing is clearance-fitted with the piston rod, and the rear hydrostatic bearing works in conjunction with the front hydrostatic bearing to ensure the smooth movement of the piston rod.

[0012] Preferably, it also includes a cylinder, wherein the piston rod, the front hydrostatic bearing and the rear hydrostatic bearing are all disposed inside the cylinder, and the cylinder is connected to the front hydrostatic bearing and the rear hydrostatic bearing.

[0013] Preferably, it also includes a trunnion, which is detachably connected to the cylinder.

[0014] Preferably, it also includes a dustproof ring cover, which is sealed to the piston rod by a sealing ring, and the dustproof ring cover is detachably connected to the front hydrostatic bearing and the rear hydrostatic bearing.

[0015] Preferably, it also includes a slit throttle, which is detachably connected to the front hydrostatic bearing and the rear hydrostatic bearing, and the slit throttle is used to adjust the flow rate of hydraulic oil.

[0016] Preferably, it also includes a valve plate, which is detachably connected to the cylinder, and the valve plate is used to assist in adjusting the movement of the piston rod.

[0017] Preferably, it also includes an oil drain pipe, which is detachably connected to the rear hydrostatic bearing and the valve plate, and the oil drain pipe is used to recover and discharge the hydraulic oil leaking from the rear hydrostatic bearing.

[0018] Preferably, the front hydrostatic bearing is detachably connected to the dust cover, the cylinder, and the slit throttle via screws and a sealing ring, and the rear hydrostatic bearing is detachably connected to the dust cover, the cylinder, and the slit throttle via screws and a sealing ring.

[0019] Preferably, it further includes a compensation element and an oil supply system, wherein the oil supply system is connected to the front hydrostatic bearing and the rear hydrostatic bearing through the compensation element and is used to supply oil to them.

[0020] A centrifuge includes a hydrostatic support servo actuator, wherein the hydrostatic support servo actuator is any one of the hydrostatic support servo actuators described above.

[0021] This utility model provides a hydrostatic support servo actuator. The titanium alloy piston rod is sealed with the front and rear hydrostatic bearings through a clearance fit. The titanium alloy piston rod is an important component for force transmission in the actuator, possessing high strength, rigidity, and bending stability. It can withstand various forces such as tension, pressure, bending force, and vibration impact. The use of titanium alloy material reduces the mass of the piston rod, thereby reducing the inertial force it bears under 100g centrifugal force conditions. Both the front and rear hydrostatic bearings are clearance-fitted with the piston rod, providing non-contact hydrostatic support and bidirectional hydrostatic support. This ensures the stability and accuracy of the piston rod throughout its stroke, improves the stability of the hydrostatic support servo actuator, and ensures stable and normal operation under high-g test conditions. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the hydrostatic support servo actuator provided by this utility model.

[0024] Figure 2 This is a front view of the hydrostatic support servo actuator provided by this utility model;

[0025] Figure 3 This is a side view of the hydrostatic support servo actuator provided by this utility model;

[0026] Figure 4 This is a top view of the hydrostatic support servo actuator provided by this utility model.

[0027] Figure label:

[0028] 1-Piston rod; 2-Dust seal cover; 3-Front hydrostatic bearing; 4-Trundle; 5-Rear hydrostatic bearing; 6-; 7-Slit throttle; 8-Valve plate; 9-Drain pipe. Detailed Implementation

[0029] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0030] The core of this utility model is to provide a hydrostatic support servo actuator. This actuator, by using a titanium alloy piston rod and cooperating with a front hydrostatic bearing and a rear hydrostatic bearing, can work stably and normally under high g-value test conditions.

[0031] Another core aspect of this invention is to provide a centrifuge that includes the aforementioned hydrostatic support servo actuator.

[0032] It should be noted that the orientation or positional relationship indicated by terms such as "upper", "lower", "front", and "rear" is based on the orientation or positional relationship shown in the accompanying drawings and is only for the purpose of facilitating the description of this application and simplifying the description. It is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0033] This application provides a hydrostatic support servo actuator, comprising: a piston rod 1, a front hydrostatic bearing 3, and a rear hydrostatic bearing 5;

[0034] Among them, piston rod 1 is a titanium alloy structural component;

[0035] The front hydrostatic bearing 3 is clearance-fitted with the piston rod 1, and the front hydrostatic bearing 3 is used to ensure the smooth movement of the piston rod 1;

[0036] The rear hydrostatic bearing 5 is clearance-fitted with the piston rod, and the rear hydrostatic bearing 5 works in conjunction with the front hydrostatic bearing 3 to ensure the smooth movement of the piston rod 1.

[0037] Specifically, please refer to the appendix for the structure of the hydrostatic support servo actuator of this application. Figure 2The uppermost part is the piston rod 1, which is sealed with the front hydrostatic bearing 3 and the rear hydrostatic bearing 5 through a clearance fit. The titanium alloy piston rod 1 is an important component for transmitting force in the actuator. The titanium alloy material provides high strength, rigidity, and bending stability, and can withstand various forces such as tension, pressure, bending force, and vibration impact. Using titanium alloy reduces the mass of the piston rod 1, thus reducing the inertial force it bears under 100g centrifugal force conditions. The front hydrostatic bearing 3 is located at the front end of the piston rod 1, providing non-contact hydrostatic support, reducing friction and wear, and ensuring the smooth movement of the piston rod 1. The rear hydrostatic bearing 5 is located at the rear end of the piston rod 1, working together with the front hydrostatic bearing 3 to provide bidirectional hydrostatic support, ensuring the stability and accuracy of the piston rod 1 throughout its stroke, and improving the stability of the hydrostatic support servo actuator, so as to ensure that it can work stably and normally under high-g test conditions.

[0038] Based on the above embodiment, it also includes a cylinder 6, a piston rod 1, a front hydrostatic bearing 3 and a rear hydrostatic bearing 5, all of which are disposed inside the cylinder 6, and the cylinder 6 is connected to the front hydrostatic bearing 3 and the rear hydrostatic bearing 5.

[0039] Specifically, cylinder 6, as the outer shell of the actuator, can accommodate piston rod 1 and hydraulic oil, providing a sealing and pressure cavity. It is a key component of hydraulic actuation. Cylinder 6 adopts a cylindrical structure and is connected and sealed with front hydrostatic bearing 3 and rear hydrostatic bearing 5 through screws and sealing rings. Cylinder 6 is also sealed with piston rod 1 through clearance fit. Cylinder 6 is a key component in the hydrostatic support servo actuator for 100g centrifuges, playing a crucial role in connecting the upper and lower parts. It has extremely high precision requirements. In addition, cylinder 6 has high strength, rigidity and impact toughness, and can withstand hydraulic pressure exceeding 40MPa, load force exceeding 55T and unexpected impact force, and has a hydraulic buffer function.

[0040] Based on the above embodiment, it also includes a trunnion 4, which is detachably connected to the cylinder 6.

[0041] Specifically, the trunnion 4 is used to connect the piston rod 1 and the external load, transmit force and motion, and allow a certain degree of free rotation or oscillation. The trunnion 4 is connected to the cylinder 6 by screws. By connecting and cooperating with the external rotating mechanism, the servo actuator can rotate at any angle along the axis of the rotating shaft to achieve loading at different angles.

[0042] Based on the above embodiment, a dustproof ring cover 2 is also included. The dustproof ring cover 2 is sealed to the piston rod 1 through a sealing ring. The dustproof ring cover 2 is detachably connected to the front hydrostatic bearing 3 and the rear hydrostatic bearing 5.

[0043] Specifically, the dustproof ring cover 2 is sealed to the piston rod 1 through the sealing ring, and is connected and sealed to the front hydrostatic bearing 3 and the rear hydrostatic bearing 5 through screws and the sealing ring, which serves to fix the dustproof ring, block external pollutants, prevent external dust and impurities from entering the actuator, and protect the internal components from contamination.

[0044] Based on the above embodiments, a slit throttle 7 is also included. The slit throttle 7 is detachably connected to the front hydrostatic bearing 3 and the rear hydrostatic bearing 5. The slit throttle 7 is used to adjust the flow rate of hydraulic oil.

[0045] Specifically, the slit throttle 7 is used to adjust the oil film thickness and pressure distribution of the front hydrostatic bearing 3 and the rear hydrostatic bearing 5. It controls the oil flow rate through throttling, ensuring the stability and rigidity of the hydrostatic support. The slit throttle 7 is connected and sealed to the front hydrostatic bearing 3 and the rear hydrostatic bearing 5 via screws and sealing rings. Through precise design, the high-pressure oil is throttled to form a uniform and stable hydrostatic oil film, achieving contactless support for the piston rod 1, avoiding mechanical friction and wear. Under a centrifugal force of 100g, it can resist radial displacement of the piston rod 1, adapting to high-frequency motion requirements. It features high oil film rigidity, strong anti-contamination ability, and fast dynamic response.

[0046] Based on the above embodiments, a valve plate 8 is also included. The valve plate 8 is detachably connected to the cylinder 6 and is used to assist in adjusting the movement of the piston rod 1.

[0047] Specifically, the valve plate 8 is connected and sealed to the cylinder 6 by screws and sealing rings. The valve plate 8 is used to install the servo valve and pressure measuring interface, and to input and output hydraulic oil to the actuator. The high pressure oil circuit at the input port distributes the hydrostatic support oil supply, and the return oil circuit at the output port merges into the hydrostatic support gap return oil, that is, to control the flow direction and flow rate of the hydraulic oil, so as to achieve precise control of the piston rod movement.

[0048] Based on the above embodiment, it also includes an oil drain pipe 9, which is detachably connected to the rear hydrostatic bearing 5 and the valve plate 8. The oil drain pipe 9 is used to recover and discharge the hydraulic oil leaked from the rear hydrostatic bearing 5.

[0049] Specifically, the drain pipe 9 is connected and sealed to the rear hydrostatic bearing 5 and valve plate 8 through threads and hydraulic joints to recover and discharge the oil leaking from the hydrostatic bearing, keep the system oil clean and circulate, and prevent oil accumulation and contamination.

[0050] Based on the above embodiments, the front hydrostatic bearing 3 is detachably connected to the dust cover 2, cylinder 6, and slit throttle 7 via screws, sealing rings, and a slit throttle 7. The rear hydrostatic bearing 5 is detachably connected to the dust cover 2, cylinder 6, and slit throttle 7 via screws, sealing rings, and a slit throttle 7.

[0051] Specifically, the sealing ring is not simply a gasket; it integrates three functions into a single annular groove: end-face static pressure sealing, radial dustproof sealing, and self-tightening alignment. The direct benefits can be summarized as: enabling bearings to be quickly and manually disassembled and assembled under high-g testing conditions with zero leakage, zero wear, and zero eccentricity. Specific advantages can be broken down into quantifiable indicators: 1. End-face static pressure self-compensation reduces static leakage by two orders of magnitude compared to traditional O-rings, requiring no additional tightening force and reducing screw torque during disassembly and assembly; 2. Radial centrifugal locking: at high centrifugal acceleration, the chamfered outer lip of the sealing ring generates radial self-tightening, automatically eliminating micro-gaps between the bearing and cylinder, significantly reducing bearing eccentricity, improving coaxiality, and enhancing the stability of the static pressure-supported servo actuator; 3. Doubled lifespan, reduced particle size, and end-face static pressure reducing the probability of metal-to-metal contact to zero, significantly reducing sealing ring wear and lowering the servo valve jamming failure rate.

[0052] Based on the above embodiments, a compensation element and an oil supply system are also included. The oil supply system is connected to the front hydrostatic bearing 3 and the rear hydrostatic bearing 5 through the compensation element and is used to supply oil to them.

[0053] Specifically, the external oil supply system supplies pressurized oil to the front hydrostatic bearing 3 and the rear hydrostatic bearing 5. This oil is delivered to the oil chambers of the front and rear hydrostatic bearings 3 and 5 through a compensating element, forming a sufficiently pressurized lubricating oil film that lifts the piston rod, ensuring that the piston rod 1 remains centered within the front and rear hydrostatic bearings 3 and 5 at all times. The hydrostatic pressure of the liquid supports the external load, guaranteeing that the piston rod 1 is in a state of complete liquid lubrication with the front and rear hydrostatic bearings 3 and 5 at any speed and under any predetermined load.

[0054] In general, in some embodiments, the hydrostatic support servo actuator provided in this application can withstand a centrifugal force of 100g in the radial direction of the piston rod and operate normally. The rated output load can reach 550kN, the test frequency can reach 200Hz, the rated flow rate can reach 1200L / min, and the starting pressure is ≤0.005MPa. It is suitable for working conditions where the piston rod is subjected to a large radial centrifugal force.

[0055] In addition to the aforementioned hydrostatic support servo actuator, this utility model also provides a centrifuge that includes the hydrostatic support servo actuator disclosed in the above embodiments. For the structure of other parts of the centrifuge, please refer to the prior art, which will not be repeated here.

[0056] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0057] The above provides a detailed description of the hydrostatic support servo actuator and centrifuge provided by this utility model. Specific examples have been used to illustrate the principle and implementation of this utility model. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core idea of ​​this utility model. It should be noted that those skilled in the art can make several improvements and modifications to this utility model without departing from the principle of this utility model, and these improvements and modifications also fall within the protection scope of the claims of this utility model.

Claims

1. A hydrostatic support servo actuator, characterized in that, include: The piston rod (1) is a titanium alloy structural component; The front hydrostatic bearing (3) is clearance-fitted with the piston rod (1), and the front hydrostatic bearing (3) is used to ensure the smooth movement of the piston rod (1); The rear hydrostatic bearing (5) is clearance-fitted with the piston rod, and the rear hydrostatic bearing (5) works in conjunction with the front hydrostatic bearing (3) to ensure the smooth movement of the piston rod (1).

2. The hydrostatic support servo actuator according to claim 1, characterized in that, It also includes a cylinder (6), the piston rod (1), the front hydrostatic bearing (3) and the rear hydrostatic bearing (5) are all located inside the cylinder (6), and the cylinder (6) is connected to the front hydrostatic bearing (3) and the rear hydrostatic bearing (5).

3. The hydrostatic support servo actuator according to claim 2, characterized in that, It also includes a trunnion (4), which is detachably connected to the cylinder (6).

4. The hydrostatic support servo actuator according to claim 3, characterized in that, It also includes a dustproof ring cover (2), which is sealed to the piston rod (1) by a sealing ring, and the dustproof ring cover (2) is detachably connected to the front hydrostatic bearing (3) and the rear hydrostatic bearing (5).

5. The hydrostatic support servo actuator according to claim 4, characterized in that, It also includes a slit throttle (7), which is detachably connected to the front hydrostatic bearing (3) and the rear hydrostatic bearing (5), and the slit throttle (7) is used to adjust the flow rate of hydraulic oil.

6. The hydrostatic support servo actuator according to claim 5, characterized in that, It also includes a valve plate (8), which is detachably connected to the cylinder (6). The valve plate (8) is used to assist in adjusting the movement of the piston rod (1).

7. The hydrostatic support servo actuator according to claim 6, characterized in that, It also includes an oil drain pipe (9), which is detachably connected to the rear hydrostatic bearing (5) and the valve plate (8). The oil drain pipe (9) is used to recover and discharge the hydraulic oil leaked from the rear hydrostatic bearing (5).

8. The hydrostatic support servo actuator according to claim 7, characterized in that, The front hydrostatic bearing (3) is detachably connected to the dust cover (2), the cylinder (6), and the slit throttle (7) via screws and sealing rings. The rear hydrostatic bearing (5) is detachably connected to the dust cover (2), the cylinder (6), and the slit throttle (7) via screws and sealing rings.

9. The hydrostatic support servo actuator according to any one of claims 1 to 8, characterized in that, It also includes a compensation element and an oil supply system, wherein the oil supply system is connected to the front hydrostatic bearing (3) and the rear hydrostatic bearing (5) through the compensation element and is used to supply oil to them.

10. A centrifuge, comprising a hydrostatic support servo actuator, characterized in that, The hydrostatic support servo actuator is the hydrostatic support servo actuator as described in any one of claims 1 to 9.

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