A lightweight high-rigidity linear push rod module based on an aviation aluminum alloy

Abstract

This invention belongs to the field of linear module technology and discloses a lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy. The module includes a housing, a motor, a reverse roller screw, a reverse roller screw nut, an anti-rotation sleeve, a front cover, a rear cover, a bearing assembly, a drive control board, and a sensor assembly. The housing is made of aerospace aluminum alloy and is fixedly connected to the front and rear covers. The motor stator is fixed inside the housing, and the rotor is fixed to the outer surface of the reverse roller screw nut. The reverse roller screw passes through the reverse roller screw nut, and its front flat end cooperates with the anti-rotation sleeve to restrict rotational freedom, realizing the conversion of rotational motion to linear motion. The rear cover is equipped with a pressure sensor and a joint bearing. This invention achieves lightweight, high rigidity, excellent heat dissipation performance, and high integration of the module through an integrated aerospace aluminum alloy structure and reverse roller screw transmission, making it suitable for precision linear drive scenarios.

Description

Technical Field

[0001] This invention relates to the field of linear module technology, and in particular to a lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy. Background Technology

[0002] Linear actuator modules are widely used in automation equipment, robotics, aerospace, and precision machine tools to achieve precise linear motion. In existing technologies, to meet the requirements of high rigidity and high load-bearing capacity, the main structure of the actuator module, such as the housing and base, is often made of steel or cast iron. This results in a large overall weight and high inertia, limiting the acceleration and energy efficiency of the equipment. If ordinary aluminum alloys (such as A6061) are used for weight reduction, their strength, rigidity, and long-term stability are insufficient to meet the demands of high-precision, high-load operating conditions.

[0003] In addition, traditional linear actuator modules have the following shortcomings: First, insufficient heat dissipation. The motor, driver, and lead screw drive pair generate a lot of heat during operation. Traditional structural materials generally have low thermal conductivity, or poor heat dissipation design, which can easily lead to thermal deformation, affecting positioning accuracy and even triggering overheat protection shutdown. Second, complex structure and low integration. To meet functional requirements, the module is often assembled from multiple parts, resulting in numerous connection interfaces, large cumulative errors, weakened overall rigidity, and complex assembly.

[0004] Therefore, how to reduce module weight while maintaining or even improving rigidity, precision, and dynamic performance, as well as possessing excellent heat dissipation and integration, is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0005] To overcome the technical defects of the existing technology, the present invention provides a lightweight and high-rigidity linear actuator module based on aerospace aluminum alloy, including a housing, a motor, a reverse roller screw, a reverse roller screw nut, an anti-rotation sleeve, a front end cover, a rear end cover, a bearing assembly, a drive control board, and a sensor assembly. The housing serves as the main support component; the front end cover and rear end cover are fixedly connected to the front and rear ends of the housing, respectively; the motor has its stator fixed to the inner wall of the housing, and its rotor fixedly mounted on the outer cylindrical surface of the inverted roller screw nut via a sleeve; the inverted roller screw, the inverted roller screw nut, and the rollers constitute an inverted roller screw pair, and the inverted roller screw nut is a hollow cylindrical structure fitted onto the outside of the inverted roller screw; the anti-rotation sleeve is fixedly installed in the central hole of the front end cover, and the anti-rotation sleeve has a non-circular central hole; the front optical shaft of the inverted roller screw has a non-circular cross section that slides with the non-circular central hole, passes through the anti-rotation sleeve, and extends out of the front end cover; the position sensor includes an annular multi-pole pair magnet fixed to the tail end of the inverted roller screw nut and a magnetic encoder chip fixed to the drive control board; The pressure sensor is mounted on the rear end cover, and its pressure-sensing surface directly contacts the tail end of the inverted roller screw; the drive control board is fixed inside the housing and is electrically connected to the motor, the magnetic encoder chip and the pressure sensor respectively, and is used to drive the motor according to the received instructions and sensor feedback signals.

[0006] Preferably, the housing is made of 7075-T6 or 7055 aerospace aluminum alloy and is integrally formed by selective laser melting additive manufacturing or precision casting. The interior of the housing is integrally formed by the additive manufacturing process, including a stepped mounting surface, positioning steps, oil channel grooves and wiring channels.

[0007] Preferably, the inverted roller screw nut is supported inside the housing by a bearing assembly, the bearing assembly including a double-row angular contact bearing at the front end and a deep groove ball bearing at the rear end; the double-row angular contact bearing is configured back to back, its outer ring is positioned by a step inside the housing, and its inner ring is fixed to the front end of the inverted roller screw nut by a shoulder and a lock nut.

[0008] Preferably, the anti-rotation sleeve is made of tin bronze or polyether ether ketone and is press-fitted into the center hole of the front end cover; the non-circular center hole is a flat hole, the non-circular cross-section of the front end of the inverted roller screw is a flat-mouth structure, and the sliding fit clearance between the flat hole and the flat-mouth structure is 0.01-0.03mm.

[0009] Preferably, the pressure sensor is a strain gauge pressure sensor or a glass micro-fusion pressure sensor, which is threaded onto the rear end cover. Its pressure-sensing surface is in direct contact with the tail end face of the inverted roller screw, forming a direct thrust transmission path from the inverted roller screw to the tail end cover.

[0010] Preferably, the annular multipole pair magnet is bonded and fixed to the tail end face of the inverted roller screw nut by anaerobic adhesive, and its number of pole pairs matches the number of pole pairs of the motor; the air gap between the magnetic encoder chip and the annular multipole pair magnet is 0.8mm.

[0011] Preferably, the drive control board integrates a microprocessor, a three-phase bridge MOSFET drive circuit, and a communication interface; the microprocessor is configured to execute a three-loop PID control algorithm consisting of a position loop, a speed loop, and a torque loop, and to generate a PWM duty cycle signal to drive the motor based on the position and speed signals fed back by the magnetic encoder chip and the thrust signal fed back by the pressure sensor.

[0012] Preferably, a lip seal is provided between the front end cover and the inverted roller screw. The lip seal is made of polyurethane material, and its lip is in close contact with the optical axis surface of the inverted roller screw. The front end of the inverted roller screw is connected to a rod end bearing with self-aligning function via a threaded connection. The end of the rear end cover is fixed with a radial spherical bearing.

[0013] Preferably, the double-row angular contact bearing in the bearing assembly is replaced by a pair of face-to-face single-row angular contact ball bearings; the outer ring of the deep groove ball bearing is fixed to the housing (1) by a detachable bearing mount.

[0014] Preferably, the control method of the linear actuator module includes the following steps: Step S1: The drive control board receives the target position command sent by the host controller through the communication interface; Step S2: The microprocessor on the drive control board executes the position loop PID algorithm to calculate the required speed command based on the actual position signal fed back by the magnetic encoder chip and the target position command; Step S3: The microprocessor executes a speed loop PID algorithm to calculate the required current command based on the actual speed signal fed back by the magnetic encoder chip and the required speed command; Step S4: The microprocessor executes the torque loop PID algorithm, calculates the PWM duty cycle based on the actual thrust signal fed back by the pressure sensor and the required current command, and drives the three-phase bridge MOSFET circuit to generate electromagnetic torque in the motor. Step S5: The rotor of the motor directly drives the reverse roller screw nut to rotate. The rotation of the reverse roller screw is restricted by the anti-rotation sleeve, so that the reverse roller screw moves linearly along the axial direction, driving the rod end bearing and external load to move to the target position. The control update rate of the position loop, velocity loop, and torque loop is 1 kHz to 20 kHz.

[0015] The beneficial effects of this invention are: 1. This invention uses aerospace aluminum alloy as the main material, combined with an integrated molding design, which significantly reduces the overall weight of the module while reducing connection interfaces and improving the overall structural rigidity and deformation resistance. Aerospace aluminum alloy has good thermal conductivity, which, combined with the integrated structural design, can quickly conduct and dissipate the heat generated by the motor and lead screw pair, effectively reducing thermal deformation and improving positioning accuracy and continuous working capability. The motor stator, bearing assembly, drive control board and other components are integrated into the housing, and a reverse roller lead screw structure is used to realize motion conversion, reducing the number of parts and assembly links, reducing cumulative errors, and improving reliability and dynamic response performance. Closed-loop control of speed and position is realized through magnets and magnetic sensors, and force control function is realized by combining pressure sensors to meet the requirements of high-precision linear drive. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0017] Figure 1 This is a cross-sectional view of the present invention; Figure 2 This is a structural schematic diagram of the appearance of the present invention; Figure 3 This is a schematic diagram of the rod end bearing of the present invention; Figure 4 This is a schematic diagram of the motor installation according to the present invention; Figure 5 This is a schematic diagram of the installation of the anti-rotation sleeve of the present invention.

[0018] Explanation of reference numerals in the attached figures: 1. Housing; 2. Motor; 3. Front end cover; 4. Anti-rotation sleeve; 5. Rod end bearing; 6. Sealing ring; 7. Reverse roller screw; 8. Double row angular contact bearing; 9. Reverse roller screw nut; 10. Annular multipole magnet; 11. Bearing; 12. Drive control board; 13. Spherical plain bearing; 14. Rear end cover; 14.1. Pressure sensor; 15. Bearing mounting base. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the various embodiments of this invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details have been provided in the various embodiments of this invention to facilitate a better understanding of this application. However, the technical solutions claimed in the claims of this application can be implemented even without these technical details and with various variations and modifications based on the following embodiments.

[0020] like Figure 1-5 As shown, this embodiment provides a lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy, including a housing 1, a motor 2, a reverse roller screw 7, a reverse roller screw nut 9, an anti-rotation sleeve 4, a front end cover 3, a rear end cover 14, a bearing assembly, a drive control board 12, and a sensor assembly.

[0021] The housing 1 serves as the main supporting component of the entire module, undertaking the positioning and load transfer functions of all internal components. The beneficial effects of this structure are: without significantly increasing the weight, it greatly increases the convective heat exchange area between the housing 1 and the outside world. Combined with the excellent thermal conductivity of aerospace aluminum alloy (approximately 130-160 W / (m·K)), it can quickly conduct and dissipate the heat generated by the motor 2 and the inverse roller screw pair, effectively reducing the internal temperature rise of the module, suppressing the impact of thermal deformation on positioning accuracy, avoiding shutdown caused by overheat protection, and thus supporting the module to operate continuously under high load for a long time.

[0022] The housing 1 is preferably made of 7075-T6 or 7055 aerospace aluminum alloy and integrally formed using selective laser melting (SLM) additive manufacturing or precision casting. The tensile strength of 7075-T6 aluminum alloy can reach over 570 MPa, comparable to ordinary steel, but its density is only about 1 / 3 that of steel. This allows for significant weight reduction while maintaining structural rigidity and load-bearing capacity. Furthermore, when using additive manufacturing, stepped mounting surfaces, positioning steps, oil channels, and wiring channels can be integrally formed inside the housing 1. This brings multiple benefits, including: First, it eliminates the need for extensive subsequent machining of the housing, reducing manufacturing processes and costs; second, it eliminates the unavoidable connection interfaces and assembly errors inherent in traditional multi-part splicing structures, significantly improving the coaxiality and positional accuracy of core components such as the motor stator and bearings, thereby enhancing the rigidity and transmission efficiency of the entire transmission chain; third, the integrated oil channels facilitate long-term lubrication of the inverted roller screw pair, while the integrated wiring channels protect internal cables, improving the module's reliability and neatness.

[0023] The front cover 3 and the rear cover 14 are fixedly connected to the front and rear ends of the housing 1 by bolts or screws, respectively. The stator of the motor 2 is fixed to the inner wall of the housing 1 by interference fit or bonding. Its rotor is installed on the outer cylindrical surface of the inverted roller screw nut 9 by sleeve or direct fixing. This structure of direct integration of "motor rotor-transmission nut" eliminates the intermediate transmission links such as couplings, belts or gears between the motor shaft and the screw in traditional push rod modules, bringing the following significant benefits: completely eliminating transmission backlash, improving the control rigidity and positioning accuracy of the system; reducing rotational inertia and axial dimensions, making the module have higher dynamic response acceleration; and simplifying the assembly structure and reducing the failure rate.

[0024] The inverted roller screw 7, the inverted roller screw nut 9, and multiple rollers constitute an inverted roller screw pair. Compared with traditional ball screws, roller screws use multiple threaded rollers as rolling elements, and the contact form is line contact rather than point contact, which greatly improves the load-bearing capacity and impact resistance, making them suitable for high-load and high-rigidity applications. The inverted roller screw nut 9 is a hollow cylindrical structure that is sleeved on the outside of the inverted roller screw 7. This inverted layout makes the screw itself a telescopic output end, resulting in a compact structure and a long effective stroke.

[0025] The inverted roller screw nut 9 is supported inside the housing 1 by a bearing assembly. In a preferred embodiment, the bearing assembly includes a double-row angular contact bearing 8 at the front end and a deep groove ball bearing 11 at the rear end. The double-row angular contact bearings 8 are arranged back-to-back (i.e., the pressure lines of the two rows of bearings form an "O" shape), which can simultaneously withstand large radial loads and bidirectional axial loads, and has a high anti-overturning moment capability. This is crucial for supporting the inverted roller screw nut 9 in its long-stroke extended state, effectively ensuring the rigidity of the screw during movement. Its outer ring is positioned by a step inside the housing 1, and the inner ring is fixed to the front end of the inverted roller screw nut 9 by a shoulder and a lock nut. This positioning method eliminates axial movement of the bearing and ensures transmission accuracy. In another embodiment, the double-row angular contact bearing 8 can be replaced with a pair of face-to-face single-row angular contact ball bearings, which can also provide bidirectional axial positioning and are easier to adjust the preload under certain operating conditions; the outer ring of the deep groove ball bearing 11 can be fixed in the housing 1 by a detachable bearing mounting seat 15. The advantage is that when it is necessary to repair or replace internal components, the bearing seat can be easily removed together with the rear components, which significantly improves the maintainability of the module.

[0026] The anti-rotation sleeve 4 is fixedly installed in the center hole of the front end cover 3, preferably with an interference fit to ensure its position is absolutely fixed. The anti-rotation sleeve 4 has a non-circular center hole, such as a flat hole, a square hole, or a spline hole. The front end of the inverted roller screw 7 has a non-circular cross section (such as a flat-mouth structure) that slides with the non-circular center hole. This front end passes through the anti-rotation sleeve 4 and extends out of the front end cover 3. The sliding fit between the anti-rotation sleeve 4 and the front end of the inverted roller screw 7 restricts the rotational freedom of the screw, allowing it to move only in a linear motion along the axial direction. This is the key to converting the rotational motion of the nut into the linear motion of the screw. To reduce friction and wear and ensure backlash-free transmission, the anti-rotation sleeve 4 is preferably made of tin bronze. Made of either polyetheretherketone (PEEK) material (which has good self-lubricating and wear resistance) or PEEK material (which has an extremely low coefficient of friction and excellent fatigue resistance), in one specific embodiment, the non-circular central hole is a flat hole, and the non-circular cross-section of the front end of the inverted roller screw 7 is a flat structure. The sliding fit clearance between the two is 0.01-0.03mm. This precision clearance range has been optimized: too large a clearance will cause radial wobble of the screw, affecting accuracy and generating impact noise; too small a clearance may cause jamming due to thermal expansion or micro-contaminants. The clearance of 0.01-0.03mm can ensure smooth low-friction sliding and effectively limit rotation, achieving "zero backlash" linear drive.

[0027] The position sensor includes an annular multipole magnet 10 fixed to the tail end of the inverted roller screw nut 9 and a magnetic encoder chip fixed to the drive control board 12. The annular multipole magnet 10 is preferably fixed by anaerobic adhesive. After curing, the anaerobic adhesive has high strength and vibration resistance, ensuring that the magnet will not fall off under high-speed rotation. Its pole pair number matches the pole pair number of the motor 2, thus making the electrical angle signal output by the encoder directly correspond to the angle signal required for motor commutation, simplifying the control algorithm. The magnetic encoder chip and the annular multipole magnet 10... The air gap between the multipole magnets 10 is preferably 0.8mm. This air gap value represents the optimal balance between signal strength and anti-interference capability: if the air gap is too small, the installation precision requirements are stringent, and friction is likely to occur; if the air gap is too large, the magnetic field strength sensed by the Hall element weakens, introducing measurement errors. The 0.8mm air gap allows for certain installation tolerances while providing clear and stable position and speed feedback signals for accurately detecting the angular position and rotational speed of the rotor (i.e., the inverted roller screw nut 9), thereby indirectly obtaining the linear position and speed of the screw. Compared to traditional photoelectric encoders, magnetic encoders have advantages such as oil resistance, vibration resistance, and small size, making them very suitable for the working environment of push rod modules.

[0028] The pressure sensor 14.1 is mounted on the rear end cover 14, and its pressure-sensing surface directly contacts the tail end face of the inverted roller screw 7. Preferably, the pressure sensor 14.1 is a strain gauge pressure sensor or a glass micro-fusion pressure sensor, and is threaded onto the rear end cover 14, forming a direct thrust transmission path from the inverted roller screw 7 to the tail end cover 14. The core advantage of this design is that it achieves direct measurement of thrust rather than indirect estimation. When the inverted roller screw 7 outputs thrust, its tail end directly presses against the pressure sensor 14.1, and the strain gauge generates an electrical signal proportional to the thrust. Compared to the method of indirectly estimating thrust by detecting motor current (current is affected by various factors such as temperature, back electromotive force, and friction, resulting in low accuracy), the direct measurement method has high accuracy, fast response, and is unaffected by changes in motor parameters. This enables the drive control board 12 to achieve true "force closed-loop control" and precisely adjust the output thrust, which is of decisive significance for scenarios that require constant force control (such as grinding, polishing, and assembly) or force-position hybrid control (such as precision press fitting).

[0029] The drive control board 12 is fixed inside the housing 1 and is electrically connected to the windings of the motor 2, the magnetic encoder chip, and the pressure sensor 14.1. By embedding the drive control board 12 inside the housing 1, the entire module becomes a "plug-and-play" intelligent execution unit, eliminating the need for an external independent driver and simplifying the user's host computer system and wiring. The drive control board 12 integrates a microprocessor (MCU / DSP), a three-phase bridge MOSFET drive circuit, and communication interfaces (such as CAN, EtherCAT, RS485, etc.). The microprocessor is configured to execute a three-loop PID control algorithm with position, speed, and torque loops. Based on the position and speed signals fed back by the magnetic encoder chip and the thrust signal fed back by the pressure sensor 14.1, it generates a PWM duty cycle signal to drive the motor 2, achieving precise closed-loop control of position, speed, and thrust. The control update rates of the position loop, velocity loop, and torque loop can be set from 1kHz to 20kHz. A high update rate means that the control system has a high response bandwidth and can quickly correct high-frequency disturbances. This allows it to maintain extremely high positioning stiffness and trajectory tracking accuracy even under high acceleration / deceleration motion or external impact, meeting the stringent requirements of fields such as robotics and high-end CNC.

[0030] To enhance the protection level, a lip seal 6 is provided between the front end cover 3 and the inverted roller screw 7. The lip seal 6 is made of polyurethane material, with its lip tightly adhering to the optical axis surface of the inverted roller screw 7. Polyurethane material possesses excellent wear resistance, oil resistance, and tear resistance. Under pressure, the lip structure further presses against the optical axis surface, achieving a dynamic seal. This seal effectively prevents external dust, cutting fluid, moisture, and other contaminants from entering the module, protecting the precision roller screw pair and bearings, and extending the module's service life in harsh environments. To facilitate connection to external loads, the front end of the inverted roller screw 7 is threadedly connected to a rod end bearing 5 with a self-aligning function; the end of the rear end cover 14 is fixed with a radial spherical bearing 13. The placement of these two bearings allows for a certain angular deviation in the installation connection at both ends of the module (i.e., it can withstand a certain lateral force and misalignment), avoiding additional bending moments caused by machining errors of the mounting base or deviations in the load's movement trajectory. This protects the linear transmission components inside the module and simplifies the user's structural design.

[0031] This invention also provides a control method for the aforementioned linear actuator module. This method fully utilizes the characteristics of the aforementioned hardware structure and includes the following steps: Step S1: The drive control board 12 receives the target position command sent by the upper controller through the communication interface. Step S2: The microprocessor executes the position loop PID algorithm to calculate the required speed command based on the actual position signal fed back by the magnetic encoder chip and the target position command. The position loop is the highest level control loop, ensuring that the module can accurately reach the commanded position. Step S3: The microprocessor executes the speed loop PID algorithm to calculate the required current command (i.e., the target thrust command) based on the actual speed signal fed back by the magnetic encoder chip and the required speed command. The speed loop ensures the smoothness and speed of position tracking by adjusting the speed, and its output serves as the command of the inner loop. Step S4: The microprocessor executes the torque loop (current loop) PID algorithm to calculate the PWM duty cycle based on the actual thrust signal fed back by the pressure sensor 14.1 and the required current command, driving the three-phase bridge MOSFET circuit to generate the corresponding electromagnetic torque of the motor 2. This is the innermost and fastest-responding control loop, which overcomes load disturbances and friction by directly controlling the output torque of the motor. Because it uses the directly measured pressure sensor 14.1 signal, the control accuracy and anti-interference capability of the torque loop are far superior to the traditional method based on phase current estimation. Step S5: The rotor of the motor 2 directly drives the rotation of the inverted roller screw nut 9, and the rotation of the inverted roller screw 7 is restricted by the anti-rotation sleeve 4, so that the inverted roller screw 7 moves linearly along the axial direction, driving the rod end bearing 5 and the external load to move precisely to the target position. Through the above three-loop cascaded control architecture, this control method realizes comprehensive and high-precision closed-loop control of the position, speed and output thrust of the push rod module, which is especially suitable for complex automation tasks that require precise force-position coordination control.

[0032] In summary, the linear actuator module provided by this invention achieves lightweight structure, high transmission rigidity, excellent heat dissipation and high-precision force and position control through high-strength aerospace aluminum alloy material, integrated additive manufacturing housing, direct integration of motor rotor and reverse roller screw nut, combined feedback of high-precision magnetoelectric encoder and contact pressure sensor, and high update rate three-loop PID control, effectively overcoming the defects of the prior art.

[0033] Those skilled in the art will understand that the above embodiments are specific examples of implementing the present invention, and in practical applications, various changes in form and detail may be made without departing from the spirit and scope of the present invention.

Claims

1. A lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy, characterized in that: It includes a housing (1), a motor (2), a reverse roller screw (7), a reverse roller screw nut (9), an anti-rotation sleeve (4), a front end cover (3), a rear end cover (14), a bearing assembly, a drive control board (12), and a sensor assembly; The housing (1) serves as the main support component; the front cover (3) and the rear cover (14) are fixedly connected to the front and rear ends of the housing (1), respectively; the motor (2) has its stator fixed to the inner wall of the housing (1), and its rotor is fixedly installed on the outer cylindrical surface of the inverted roller screw nut (9) through a sleeve; the inverted roller screw (7), the inverted roller screw nut (9) and the rollers constitute an inverted roller screw pair, and the inverted roller screw nut (9) is a hollow cylindrical structure, sleeved on the outside of the inverted roller screw (7); the anti-rotation sleeve (4) is fixedly installed in the center hole of the front cover (3), and the anti-rotation sleeve (4) has a non-circular center hole; The front optical shaft of the inverted roller screw (7) has a non-circular cross section that slides with the non-circular center hole, passes through the anti-rotation sleeve (4) and extends out of the front end cover (3); the position sensor includes an annular multipole pair magnet (10) fixed to the tail end of the inverted roller screw nut (9) and a magnetic encoder chip fixed on the drive control board (12); the pressure sensor (14.1) is installed on the rear end cover (14), and its pressure-sensing surface directly contacts the tail end of the inverted roller screw (7); the drive control board (12) is fixed inside the housing (1) and is electrically connected to the motor (2), the magnetic encoder chip and the pressure sensor (14.1) respectively, for driving the motor (2) according to the received instructions and sensor feedback signals.

2. The lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy according to claim 1, characterized in that: The housing (1) is made of 7075-T6 or 7055 aerospace aluminum alloy and is integrally formed by selective laser melting additive manufacturing or precision casting. The interior of the housing (1) is integrally formed by the additive manufacturing process with a stepped mounting surface, positioning steps, oil groove and wiring channel.

3. The lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy according to claim 1, characterized in that: The inverted roller screw nut (9) is supported inside the housing (1) by a bearing assembly, which includes a double-row angular contact bearing (8) at the front end and a deep groove ball bearing (11) at the rear end. The double-row angular contact bearing (8) is arranged back to back, with its outer ring positioned by a step inside the housing (1) and its inner ring fixed to the front end of the inverted roller screw nut (9) by a shoulder and a locking nut.

4. The lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy according to claim 1, characterized in that: The anti-rotation sleeve (4) is made of tin bronze or polyether ether ketone and is press-fitted into the center hole of the front end cover (3); the non-circular center hole is a flat hole, the non-circular section of the front end of the inverted roller screw (7) is a flat-mouth structure, and the sliding fit clearance between the flat hole and the flat-mouth structure is 0.01-0.03mm.

5. A lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy according to claim 1, characterized in that: The pressure sensor (14.1) is either a strain gauge pressure sensor or a glass micro-fusion pressure sensor. It is threaded onto the rear end cover (14), and its pressure-sensing surface is in direct contact with the tail end face of the inverted roller screw (7), forming a direct thrust transmission path from the inverted roller screw (7) to the tail end cover (14).

6. A lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy according to claim 1, characterized in that: The annular multipole pair magnet (10) is bonded to the tail end face of the inverted roller screw nut (9) by anaerobic adhesive, and its number of pole pairs matches the number of pole pairs of the motor (2); the air gap between the magnetic encoder chip and the annular multipole pair magnet (10) is 0.8mm.

7. A lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy according to claim 1, characterized in that: The drive control board (12) integrates a microprocessor, a three-phase bridge MOSFET drive circuit and a communication interface; the microprocessor is configured to execute a three-loop PID control algorithm of position loop, speed loop and torque loop, and generate a PWM duty cycle signal to drive the motor (2) based on the position and speed signals fed back by the magnetic encoder chip and the thrust signal fed back by the pressure sensor (14.1).

8. A lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy according to claim 1, characterized in that: A lip seal (6) is provided between the front end cover (3) and the inverted roller screw (7). The lip seal (6) is made of polyurethane material, and its lip is in close contact with the optical axis surface of the inverted roller screw (7). The front end of the inverted roller screw (7) is connected to a rod end bearing (5) with self-aligning function by a thread. The end of the rear end cover (14) is fixed with a radial joint bearing (13).

9. A lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy according to claim 1, characterized in that: The double-row angular contact bearing (8) in the bearing assembly is replaced by a pair of face-to-face single-row angular contact ball bearings; the outer ring of the deep groove ball bearing (11) is fixed to the housing (1) by a removable bearing mount (15).

10. A lightweight, high-rigidity linear actuator module based on aerospace aluminum alloy according to any one of claims 1-9, characterized in that: The control method of the linear push rod module includes the following steps: Step S1: The drive control board (12) receives the target position command sent by the upper controller through the communication interface; Step S2: The microprocessor on the drive control board (12) executes the position loop PID algorithm to calculate the required speed command based on the actual position signal fed back by the magnetic encoder chip and the target position command; Step S3: The microprocessor executes a speed loop PID algorithm to calculate the required current command based on the actual speed signal fed back by the magnetic encoder chip and the required speed command; Step S4: The microprocessor executes the torque loop PID algorithm, calculates the PWM duty cycle based on the actual thrust signal fed back by the pressure sensor (14.1) and the required current command, and drives the three-phase bridge MOSFET circuit to generate electromagnetic torque in the motor (2); Step S5: The rotor of the motor (2) directly drives the reverse roller screw nut (9) to rotate. The rotation of the reverse roller screw (7) is restricted by the anti-rotation sleeve (4), so that the reverse roller screw (7) moves linearly along the axial direction, driving the rod end bearing (5) and the external load to move to the target position. The control update rate of the position loop, velocity loop, and torque loop is 1 kHz to 20 kHz.

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