electrical cylinder

Abstract

The application discloses an electric cylinder, which comprises a power module, a reduction gear module, a driving module, a force control sensor, an angle sensor and a displacement sensor, wherein the main shaft of the power module extends in a first direction; the reduction gear module is in transmission connection with the main shaft of the power module; the driving module is in transmission connection with the reduction gear module; the force control sensor is installed at the rear end of the power module and is used for operatively detecting external extrusion force; the angle sensor is connected with the power module and is used for operatively detecting the rotation angle of the main shaft; and the displacement sensor is installed on the driving module and is used for operatively sensing the displacement of the driving module.

Description

Technical Field

[0001] This invention relates to the field of electric cylinder structure technology, and particularly to an electric cylinder. Background Technology

[0002] As highly anthropomorphic mechanical systems, humanoid robots require joint designs that precisely replicate the freedom and flexibility of human limb movement. Guided by bionic principles, robot joints must achieve multi-degree-of-freedom coordinated movement. The swinging movements of human arms, hips, and finger joints are essentially complex rotational and translational movements driven by multiple sets of mechanisms, and robots must simulate this biomechanical characteristic through mechanical structures.

[0003] Currently, robot drive methods are mainly divided into two major schools: linear drive and rotary drive. Linear drive can be achieved using electric cylinders.

[0004] Electric cylinders convert the rotational motion of servo motors into linear motion. Currently, in some precision applications, existing electric cylinders lack sufficient displacement feedback, angle rotation, or force control precision, making them unsuitable for such applications. Summary of the Invention

[0005] The purpose of this invention is to provide an electric cylinder to solve the problems of the prior art.

[0006] To solve the above-mentioned technical problems, embodiments of the present invention provide an electric cylinder, comprising: The power module has its main shaft extending along a first direction; A reduction gear module, wherein the reduction gear module is connected to the main shaft of the power module via a transmission connection; The drive module is connected to the reduction gear module in a transmission manner; A force control sensor is installed at the rear end of the power module and is operable to detect external compressive force. An angle sensor, which is connected to the power module, is operable to detect the rotation angle of the spindle; A displacement sensor is installed on the drive module and can be operated to sense the displacement of the drive module.

[0007] In one embodiment, the power module includes: Power casing; Rotor magnet, wherein the rotor magnet is arranged in a ring outside the main shaft; Motor windings, which are sleeved around the rotor magnets; The motor core is wrapped around the motor windings, and the motor core and the rotor magnet cooperate to drive the main shaft to rotate; The main shaft extends beyond both ends of the rotor magnet along the first direction; The angle sensor includes: A magnet, which is mounted at the rear end of the spindle; An encoder, which is mounted on the power housing and cooperates with the magnet to detect the rotation angle of the spindle.

[0008] In one embodiment, the magnet ring is disposed at the rear end of the spindle; The power housing includes: A cylindrical housing surrounds the outside of the motor core; A rear end cover, which is connected to the rear end of the cylindrical shell; The encoder is mounted on the rear cover.

[0009] In one embodiment, the rear end of the rear end cover is further provided with a mounting groove; The mounting groove includes a rear section and a front section. The rear section is formed by a recess at the rear end of the rear end cover and opens toward the top surface of the rear end cover. The front section is formed by a portion of the rear section extending to the front end of the rear end cover. The encoder is installed at the front end; The electric cylinder also includes a circuit board, the bottom of which is located at the rear section and connected to the encoder, and the top of which is attached to the top surface of the power housing.

[0010] In one embodiment, the force control sensor includes: An elastic connector is installed at the rear end of the rear end cover. The front end face of the elastic connector is provided with a groove communicating with the rear end, and the rear end face is provided with a stud. A sensor circuit board, wherein the sensor circuit board is mounted in the groove and connected to the circuit board; A strain gauge is installed in the groove and connected to the sensor circuit board; A retaining sleeve, which is connected to the stud; A fisheye radial bearing is mounted on the outside of the fixed sleeve.

[0011] In one embodiment, the force control sensor further includes a positioning element, which is mounted outside the stud and located at the front end of the fixing sleeve.

[0012] In one embodiment, the electric cylinder further includes a plurality of first mounting shafts; The cylindrical shell, the rear end cover, and the elastic connector are respectively mounted on a plurality of first mounting shafts.

[0013] In one embodiment, the cylindrical shell and the elastic connector are both rectangular cylindrical. The rear cover has a rectangular cover structure. The four first mounting shafts are respectively mounted at the four corners of the cylindrical housing, the rear end cover, and the elastic connector.

[0014] In one embodiment, the reduction gear module is a planetary reduction gear.

[0015] In one embodiment, the reduction gear module includes: Reduction gear housing; A gear ring, which is fixedly installed inside the housing of the reduction gear; A primary planetary carrier, which is rotatably mounted within the gear ring; Multiple first-stage planetary gears are mounted at the front end of the first-stage planetary carrier and mesh with the internal teeth of the gear ring. A primary sun gear, which is connected to the front end of the main shaft and located between the primary planetary gears and meshes with the primary planetary gears; The drive module is connected to the front end of the primary planetary carrier.

[0016] In one embodiment, the reduction gear module includes: Reduction gear housing; A gear ring, which is fixedly installed inside the housing of the reduction gear; A primary planetary carrier, which is rotatably mounted within the gear ring; Multiple first-stage planetary gears are mounted at the front end of the first-stage planetary carrier and mesh with the internal teeth of the gear ring. A primary sun gear, which is connected to the front end of the main shaft and located between the primary planetary gears and meshes with the primary planetary gears; A secondary planetary carrier, which is rotatably mounted inside the gear ring and located at the front end of the primary planetary carrier; Multiple secondary planetary gears are mounted at the front end of the secondary planetary carrier and mesh with the internal teeth of the gear ring. A second-stage sun gear, which is connected to the rear end of the first-stage planet carrier and meshes with a plurality of second-stage planet gears; The drive module is connected to the front end of the secondary planetary carrier.

[0017] In one embodiment, the driving module includes: A drive housing, which is connected to the reduction gear housing; A lead screw, which is installed inside the drive housing and whose rear end is connected to the front end of the secondary planetary carrier; A push rod, which is installed inside the drive housing and threadedly connected to the lead screw.

[0018] In one embodiment, the electric cylinder further includes: A top cover that fits over the top of the drive module; An integrated board, which is connected to the top cover; The displacement sensor includes: A magnetic scale, which is mounted on the push rod; A magnetic grating sensor, which is mounted on the integrated board.

[0019] In one embodiment, the electric cylinder further includes a mounting base; The mounting base is installed outside the lead screw and has a receiving groove on its top surface; The magnetic scale is installed in the receiving groove.

[0020] In one embodiment, the electric cylinder further includes a second mounting shaft that extends along the first direction and is mounted within the drive housing; The mounting base is movably mounted on the second mounting shaft. Attached Figure Description

[0021] Figure 1 and Figure 2 This is an exploded view of an electric cylinder according to an embodiment of the present invention.

[0022] Figure 3 yes Figure 1 Exploded view of the power module, reduction gear module and drive module in the embodiment shown.

[0023] Figure 4 yes Figure 1 Exploded view of the reduction gear module and drive module in the embodiment shown.

[0024] Figure 5 yes Figure 1 An exploded view of the secondary planetary carrier, three secondary planetary gears, and drive module in the illustrated embodiment.

[0025] Figure 6 yes Figure 1 The assembly diagram of the force control sensor, power module, reduction gear module and drive module in the embodiment shown.

[0026] Figure 7 yes Figure 1 The exploded view of the force control sensor, power module, reduction gear module and drive module in the embodiment shown.

[0027] Figure 8 yes Figure 1 Assembly diagram of the electric cylinder in the illustrated embodiment.

[0028] Figure 9 yes Figure 8 A cross-sectional view along line AA in the illustrated embodiment.

[0029] Figure 10 yes Figure 9 An enlarged view of region B in the illustrated embodiment.

[0030] Reference numerals: 100, Electric cylinder; 1, Power module; 11, Power housing; 111, Cylindrical housing; 1111 First shaft hole; 112, Rear end cover; 1121, Second shaft hole; 1122, Mounting slot; 12, Rotor magnet; 13, Motor winding; 14, Motor core; 15, Main shaft; 2, Reduction gear module; 21, Reduction gear housing; 211, Third shaft hole; 22, Gear ring; 23, First-stage sun gear; 24, First-stage planetary carrier; 25, First-stage planetary gear; 26, Second-stage sun gear; 27, Second-stage planetary gear; 28, Second-stage planetary carrier; 3, Drive module; 31, Drive housing; 311, Fourth shaft hole; 32, Lead screw; 33, Push rod; 34, Front end cover; 341. Clearance hole; 35. Connecting sleeve; 36. Second mounting shaft; 37. Bearing seat; 4. Force control sensor; 41. Elastic connector; 411. Cylindrical cover; 412. Rear side plate; 413. Recessed area; 42. Stud; 421. Positioning ring; 43. Sensor circuit board; 44. Strain gauge; 45. Fixing sleeve; 46. Fisheye radial bearing; 47. Positioning groove; 48. Positioning component; 5. Angle sensor; 51. Magnet; 52. Encoder; 53. Circuit board; 531. Upper section; 532. Lower section; 6. Displacement sensor; 61. Magnetic scale; 62. Magnetic scale sensor; 7. First mounting shaft; 8. Mounting seat; 9. Top cover; 10. Integrated board; X, First direction; Detailed Implementation

[0031] 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.

[0032] Unless the context requires otherwise, throughout the specification and claims, the word “comprising” and its variations, such as “including” and “having”, shall be understood to have an open, inclusive meaning, that is, to be interpreted as “including, but not limited to”.

[0033] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings to provide a clearer understanding of the purpose, features, and advantages of the present invention. It should be understood that the embodiments shown in the drawings are not intended to limit the scope of the present invention, but are merely illustrative of the essential spirit of the technical solution of the present invention.

[0034] Throughout this specification, references to "an embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Therefore, the appearance of "in an embodiment" or "an embodiment" in various places throughout the specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any manner in one or more embodiments.

[0035] The singular forms “a” and “the” used in this specification and the appended claims include plural references unless otherwise expressly stated herein. It should be noted that the term “or” is generally used to mean “and” or “or” unless otherwise expressly stated herein.

[0036] In the following description, in order to clearly demonstrate the structure and working method of the present invention, a number of directional terms will be used. However, terms such as "front", "back", "left", "right", "outside", "inside", "outward", "inward", "up", and "down" should be understood as convenient terms and not as limiting terms.

[0037] This invention relates to an electric cylinder 100, such as... Figure 1 and Figure 2 As shown, the electric cylinder 100 includes a power module 1, a reduction gear module 2, a drive module 3, a force control sensor 4, an angle sensor 5, and a displacement sensor 6. The power module 1 is driven by a coreless servo motor, causing its main shaft 15 to rotate. The main shaft 15's torque is increased by the reduction gear module 2 and transmitted to the drive module 3. The drive module 3 has a lead screw and nut structure, and the extension and retraction of the push rod 33 is achieved through the threaded structure between the lead screw and the push rod 33, and the forward and reverse rotation of the lead screw. The force control sensor 4 is located at the rear end of the power module 1. It determines the pushing pressure value of the push rod 33 by measuring the reverse pressure generated when the push rod 33 abuts against other objects. The angle sensor 5 monitors the rotation angle of the main shaft 15 of the power module 1, while the displacement sensor 6 detects the movement position of the push rod 33. The electric cylinder 100 of this invention uses the force control sensor 4, the displacement sensor 6, and the angle sensor 5 in combination to achieve triple detection feedback of position detection, angle detection, and force detection.

[0038] In one specific embodiment, such as Figure 1 , Figure 2 , Figure 3 , Figure 8 and Figure 9As shown, the power module 1 includes a power housing 11, a rotor magnet 12, a motor winding 13, a motor core 14, and a main shaft 15.

[0039] The power housing 11 includes a cylindrical housing 111 and a rear end cover 112. The cylindrical housing 111 is a cylindrical column structure extending along a first direction X, and it has openings at the front end and rear end along the first direction X. The rear end cover 112 is a rectangular block that covers the rear end opening of the cylindrical housing 111 and is fixedly assembled with the cylindrical housing 111.

[0040] The motor core 14 is an annular cylindrical shape extending along the first direction X and is fixedly installed inside the cylindrical housing 111 of the power housing 11. The motor winding 13 is an annular cylindrical shape coaxial with the motor core and is fixedly installed inside the motor core. The rotor magnet 12 is an annular cylindrical shape coaxial with the motor core and is rotatably installed inside the motor winding 13. The main shaft 15 is coaxial with the motor core and extends along the first direction X, and is fixedly sleeved inside the rotor magnet 12. The front and rear ends of the main shaft 15 extend beyond the front and rear ends of the rotor magnet 12, the motor core, and the motor winding 13, respectively. That is, the lengths of the rotor magnet 12, the motor core, and the motor winding 13 along the first direction X are basically the same, while the length of the main shaft 15 is greater than the lengths of the rotor magnet 12, the motor core, and the motor winding 13. The rotor magnet 12 and the motor core cooperate to drive the main shaft 15 to rotate around its axis.

[0041] The reduction gear module 2 is connected to the main shaft 15 of the power module 1 for transmission, and is used to stably reduce the output speed of the power module 1.

[0042] In one specific embodiment, such as Figure 4 and Figure 5 As shown, the reduction gear module 2 adopts a planetary reduction gear and includes a reduction gear housing 21, a gear ring 22, a first-stage sun gear 23, a first-stage planet carrier 24, three first-stage planet gears 25, a second-stage sun gear 26, a second-stage planet carrier 28, and three second-stage planet gears 27.

[0043] Specifically, such as Figure 5As shown, the reduction gear housing 21 is a rectangular ring, with its rear end abutting against the front end of the cylindrical housing 111. The reduction gear housing 21, the cylindrical housing 111, and the rear end cover 112 are respectively fixedly assembled by four first mounting shafts 7. The four corners of the cylindrical housing 111 are respectively provided with first shaft holes 1111, the four corners of the rear end cover 112 are respectively provided with second shaft holes 1121, and the four corners of the reduction gear housing 21 are respectively provided with third shaft holes 211. The four first shaft holes 1111, the four second shaft holes 1121, and the four third shaft holes 211 are respectively aligned along the first direction X. The four first mounting shafts 7 pass through the four first shaft holes 1111, the four second shaft holes 1121, and the four third shaft holes 211, thereby fixing the reduction gear housing 21, the cylindrical housing 111, and the rear end cover 112.

[0044] The gear ring 22 is annular and fixedly mounted on the inner wall of the reduction gear housing 21, and the gear ring 22 has internal teeth.

[0045] The first-stage planetary carrier 24 is mounted inside the gear ring 22, and three first-stage planetary gears 25 are provided at its rear end. The outer sides of the first-stage planetary gears 25 mesh with the gear ring 22, and the three first-stage planetary gears 25 are arranged at intervals. The rear end of the first-stage sun gear 23 is fixedly connected to the front end of the spindle 15, and the rear end is located in the middle of the three first-stage planetary gears 25, with the three first-stage planetary gears 25 meshing with each other. In some embodiments, the drive module 3 can be connected to the front end of the first-stage planetary carrier 24, and the first-stage planetary carrier 24 drives the drive module 3 to operate.

[0046] exist Figure 5 In the embodiment shown, a secondary sun gear 26 is fixedly disposed on the front end face of the primary planetary carrier 24. The secondary sun gear 26, the primary sun gear 23 and the main shaft 15 are coaxially disposed. The secondary sun gear 26 is installed in the middle of the three secondary planetary gears 27 and meshes with the three secondary planetary gears 27.

[0047] Three secondary planetary gears 27 are installed on the rear end face of the secondary planetary carrier and are evenly spaced. The three secondary planetary gears 27 and the secondary planetary carrier are installed inside the gear ring 22, and the three secondary planetary gears 27 mesh with the gear ring 22.

[0048] The front end face of the secondary planetary carrier is fixedly connected to the drive module 3. When the spindle 15 rotates, it will drive the three primary planetary gears 25 to rotate around the gear ring 22, thereby causing the primary planetary carrier 24 and the secondary sun gear 26 to rotate. Similarly, the secondary sun gear 26 will drive the three secondary planetary gears 27 to rotate around the gear ring 22, thereby causing the lead screw of the drive module 3 to rotate. The gear transmission process of the two planetary carriers achieves a two-stage speed reduction and torque increase effect.

[0049] It should be understood that in other embodiments, four primary planetary gears 25 or four secondary planetary gears 27 may be provided as needed for deceleration.

[0050] In the above embodiments, the reduction gear module 2 adopts a two-stage planetary reducer. In other embodiments, a single-stage planetary reducer can also be used, or a multi-stage gear can be used for reduction. In the multi-stage gear, one gear meshes with the main shaft 15, and the remaining gears mesh with each other. Reduction is achieved by changing the specifications of the gears.

[0051] The drive module 3 includes a drive housing 31, a lead screw 32, a push rod 33, a front end cover 34, and a connecting sleeve 35. The drive housing 31 is fixedly assembled with the front end face of the reduction gear housing 21. Figure 2 In the illustrated embodiment, the drive housing 31 is a rectangular ring extending along the first direction X, and the entire top end is open, making the drive housing 31 approximately C-shaped. The four corners of the drive housing 31 are each provided with a fourth shaft hole 311, through which the drive housing 31 is mounted on four first mounting shafts 7.

[0052] The drive housing 31, reduction gear housing 21, power housing 11 and rear end cover 112 are fixedly assembled by four first mounting shafts 7, which facilitates assembly. Adjacent housings can abut against each other or be connected to each other.

[0053] The front cover 34 is fitted onto the front end face of the drive housing 31, and is fixedly assembled with the front end face of the drive housing 31 and is provided with a clearance hole 341.

[0054] The lead screw 32 extends along the first direction X and is installed inside the drive housing 31. The rear end of the lead screw 32 is connected to the front end of the secondary planetary carrier, and the front end of the lead screw 32 is rotatably installed inside the drive housing 31 through the bearing seat 37. The bearing seat 37 is installed at the rear end of the drive housing 31 and abuts against the front end of the reduction gear housing 21.

[0055] The push rod 33 is installed inside the drive housing 31 and threadedly connected to the lead screw 32. After the push rod 33 is threadedly connected to the lead screw, a lead screw nut structure is formed. When the lead screw rotates, the push rod 33 will extend or retract. The connecting sleeve 35 is fitted over the push rod 33. When the push rod 33 extends or retracts, the outer end of the connecting sleeve 35 can pass through the clearance hole 341 for transmission connection with other components.

[0056] After assembly, the front cover 34, drive housing 31, reduction gear housing 21 and power housing 11 form a rectangular column structure. An integrated plate 10 and a top cover 9 are also installed on its top surface. The integrated plate 10 extends along the first direction X and basically covers the drive housing 31, reduction gear housing 21 and power housing 11, and is used to connect with the angle sensor 5, displacement sensor 6 and force control sensor 4.

[0057] The top cover 9 is fastened to the top of the front cover 34, the drive housing 31, the reduction gear housing 21 and the power housing 11, and the integrated plate 10 is fastened inside it.

[0058] The displacement sensor 6 includes a magnetic scale and a magnetic scale sensor. The magnetic scale is mounted on the push rod 33 via the mounting base 8, while the magnetic scale sensor is mounted on the integrated plate 10. The integrated plate 10 is located on the rear end cover, drive housing 31, reduction gear housing 21 and power housing 11. The magnetic scale sensor is located above the magnetic scale. The two work together to sense the displacement of the push rod 33.

[0059] Specifically, the mounting base 8 is sleeved around the push rod 33 and located at the rear end of the connecting sleeve 35. The top surface of the mounting base 8 is provided with a recessed receiving groove, which is a rectangular groove extending along the first direction X. The magnetic grating ruler is installed in the receiving groove and located below the magnetic grating sensor.

[0060] When the push rod 33 extends or retracts, it can drive the mounting base 8 and the magnetic scale to move along the first direction X within the top opening of the drive housing 31.

[0061] Two second mounting shafts 36 are also installed inside the drive housing 31. The two second mounting shafts 36 extend along the first direction X and are fixed at both ends to the front end cover 34 and the bearing seat 37, respectively. Of course, in other embodiments, the two second mounting shafts 36 can also be fixed to the inner wall of the drive housing 31.

[0062] Mounting base 8 can be movably mounted on the second mounting shaft 36, which can ensure the stable movement of mounting base 8 and increase its detection accuracy.

[0063] A magnetic grating sensor is a device that detects displacement by detecting changes in a magnetic field. The core principle can be summarized as follows: First, equally spaced magnetic stripes with alternating north (N) and south (S) poles are created on a scale, forming a magnetic grating. When the magnetic grating sensor moves along the grating, the magnetic sensing element (magnetoresistive or induction coil) inside the sensor senses the periodically changing magnetic field, generating an electrical signal with alternating strengths. The circuit then amplifies, integrates, and subdivides this signal, ultimately converting the magnetic field change into an electrical signal indicating the magnitude and direction of displacement, thus achieving position measurement.

[0064] Magnetic grating sensors use a magnetic grating as a reference, a magnetic grating ruler as a probe, and a circuit as a brain. Through magnetic field induction and electrical signal decoding, they achieve non-contact, high-precision, and highly environmentally adaptable displacement measurement, making them the core feedback element for precision motion control and automated equipment.

[0065] The angle sensor 5 includes a magnet 51 and an encoder 52. The magnet 51 is mounted at the rear end of the spindle 15. Figure 9 and Figure 10In the illustrated embodiment, the magnet 51 is looped around the radial outer surface of the main shaft 15 and is close to the rear end face of the main shaft 15. The encoder 52 is mounted on the rear end cover 112 of the power housing 11 and is spaced apart from the magnet 51 along the first direction X. When the magnet 51 rotates with the main shaft 15, the encoder 52 senses the magnetic field of the magnet 51 to determine the rotation angle of the main shaft 15.

[0066] The rear end cover 112 also has a recessed mounting groove 1122 on its rear end face. The mounting groove 1122 includes a rear section and a front section that communicate with each other along the first direction X. The rear section is formed by the recess of the rear end face of the rear end cover 112 and opens toward the top surface of the rear end cover 112 to form a top opening. The front section is formed by a portion of the front inner wall of the rear section extending to the front end of the rear end cover 112. That is, the front section communicates with the internal space of the power housing 11.

[0067] The encoder 52 is installed in the front section and connected to the integrated board 10 via a circuit board 53. The circuit board 53 includes an integrally formed upper section 531 and a lower section 532, which form an L-shape. The upper section 531 extends along a first direction X and lies flat on the top surface of the power housing 11. The upper section 531 is located on the bottom surface of the integrated board 10 and connected to the integrated board 10. The top surface of the lower section 532 is connected to the upper section 531, and its bottom end extends from the top opening of the rear section into the rear section and is electrically connected to the encoder 52.

[0068] The integrated board 10 is connected to the external circuit and transmits power to the circuit board 53. The circuit board 53 supplies power to the motor winding 13. The circuit board 53 is also bent downward and extends into the rear section of the rear end cover 112 and is connected to the encoder 52. When the magnet 51 rotates with the main shaft 15, the encoder 52, in conjunction with the magnet 51, can detect the rotation angle of the main shaft 15 and transmit it to the integrated board 10.

[0069] Force sensor 4 is installed on the rear cover 112 and determines the pushing pressure value of push rod 33 based on the reverse pressure generated when push rod 33 abuts against other objects.

[0070] The force control sensor 4 includes an elastic connector 41, a stud 42, a sensor circuit board 43, a strain gauge 44, a positioning component 48, a fixing sleeve 45, and a fisheye radial bearing 46.

[0071] The elastic connector 41 is installed at the rear end of the rear cover 112. Specifically, the elastic connector 41 includes a cylindrical cover 411 and a rear side plate 412. The cylindrical cover 411 is a cylindrical shape extending along the first direction X and has openings at both the front and rear ends. The front end face of the cylindrical cover 411 abuts against the rear end face of the rear cover plate, and a groove is formed inside it, which communicates with the rear section of the rear cover plate. Of course, in other embodiments, the groove can also be formed by a recess in the front end face of the cylindrical cover 411.

[0072] exist Figure 1 , Figure 5 and Figure 6 In the embodiment shown, the rear cover 112 is a rectangular cover, while the cylindrical cover 411 is a rectangular cylinder with a fifth shaft hole at each of the four corners.

[0073] The four first mounting shafts 7 extend through the four second shaft holes 1121 of the rear end cover 112 to the four fifth shaft holes, so that the rear end cover 112 and the cylindrical cover 411 are fixedly assembled.

[0074] As can be seen, from front to back, the drive housing 31, the reduction gear housing 21, the power housing 11 and the cylindrical cover 411 are all rectangular cylindrical structures, which are all assembled by four first mounting shafts 7. After assembly, they form a rectangular column structure extending along the first direction X.

[0075] The rear side plate 412 covers the rear end face of the cylindrical cover 411 and is integrally formed with the cylindrical cover 411. The rear end face of the rear side plate 412 is provided with a recessed area 413. The recessed area 413 is relatively large and is close to the edge of the rear side plate 412, which reduces the overall thickness of the rear side plate 412 to the required thickness. The stud 42 is connected to the front inner wall of the recessed area 413. It can be understood that the stud 42, the rear side plate 412 and the cylindrical cover 411 are integrally formed and have a certain degree of elasticity. When subjected to external force, it can transmit the force to the strain gauge 44 inside.

[0076] Specifically, strain gauge 44 is a resistance strain gauge, which is installed in the groove and fits against the inner wall of the rear side plate 412, that is, the front end face of the rear side plate 412. The sensor mounting plate is also installed in the groove and connected to strain gauge 44.

[0077] Since the groove and the rear section of the rear cover 112 are connected, the sensor circuit board 43 and the circuit board 53 can be directly electrically connected.

[0078] A positioning element is mounted on the outside of the stud 42. The positioning element is ring-fitted around the stud 42 and is positioned and assembled with the stud 42. Specifically, the front end of the stud 42 has a protruding positioning ring 421 that extends circumferentially along the stud 42. The front end face of the positioning ring 421 has a recessed positioning groove 47 that extends circumferentially along the positioning ring 421 and matches the positioning ring 421. The positioning groove 47 and the positioning ring 421 are engaged.

[0079] The fixed sleeve 45 is annular and threadedly connected to the stud 42, and the fisheye radial bearing 46 is installed on the radial outer side of the fixed sleeve 45.

[0080] The connecting sleeve 35 of the electric cylinder 100 needs to be assembled with an external driving component to drive the driving component to perform telescopic movement. When the electric cylinder 100 drives the driving component to perform the telescopic movement, it generates a reverse force. This reverse force is on the fisheye radial bearing 46. Due to the fisheye structure of the fisheye radial bearing 46, any part of it being squeezed will exert a force towards the stud 42 of the elastic connector 41, thereby causing the elastic connector 41 to generate a compressive force. When the elastic connector 41 generates a compressive force, it can transmit the compressive force to the strain gauge 44. The strain gauge 44 converts the deformation compressive force into an electrical signal and transmits it to the sensor circuit board 43. The sensor circuit board 43 is connected to the circuit board 53 and, through the circuit board 53, to the integrated board 10, realizing the signal feedback of the compressive pressure.

[0081] The force control sensor 4 operates based on the resistance strain effect. External force acts on the metal stud 42 through the fisheye radial bearing 46, causing it to undergo slight elastic deformation. The strain gauges 44 attached to the rear plate 412 change their resistance values ​​synchronously with the deformation. The strain gauges 44 form a Wheatstone bridge to convert the resistance change into a weak voltage signal. After being amplified and conditioned by the sensor circuit board 43, the output is an electrical signal that is linearly related to the magnitude of the applied external force, thereby realizing force detection and control.

[0082] The electric cylinder 100 of the present invention includes a hollow cup servo motor, a two-stage planetary reducer, a lead screw 32 nut linear actuator drive structure, a displacement sensor 6, a force control sensor 4, a circuit board 53, a sensor circuit board 43, and an integrated board 10, realizing dual closed-loop precise control of position detection and force sensing detection.

[0083] Among them, circuit board 53 adopts a flexible substrate integrated molding to replace the traditional wire harness, realizing the transmission of hollow cup servo motor drive and position feedback signals on the same board. It shares the three power supply lines of the hollow cup servo motor with the precision signal lines such as the A / B / Z phases, power supply, and ground wire of encoder 52 on the same board and isolates them in layers. While ensuring the high current transmission capacity, it suppresses electromagnetic interference through impedance matching and shielding structure to ensure the stable and reliable signal of encoder 52.

[0084] The circuit board 53 features thinness, flexibility, bendability, space saving, vibration resistance, neat wiring, and high assembly efficiency. It is suitable for scenarios with stringent requirements for installation space, anti-interference, and reliability, such as servo motors, stepper motors, integrated joints, and robot modules, enabling integrated power and signal transmission that is lightweight and highly integrated.

[0085] The reduction gear module 2 has an overall outer diameter of Φ9.2mm and adopts a two-stage planetary gear structure with a gear module of 0.2. It is a miniature precision transmission structure with a compact structure and small size. After the main shaft 15 of the power module 1 rotates, it drives the first-stage sun gear 23 to rotate, which in turn drives the first-stage planetary gear 25 to revolve around the gear ring 22. The first-stage planetary carrier 24 achieves the first reduction and torque increase. The first-stage planetary carrier 24 continues to input power as the second-stage sun gear 26, and after passing through the second-stage planetary gear 27 system, it achieves another reduction and torque increase. Finally, the power is output coaxially by the second-stage planetary carrier.

[0086] By connecting two planetary transmissions in series, a total reduction ratio of 19.2:1 is achieved, which significantly reduces the speed and increases the output torque in a very small volume, resulting in smooth transmission and high coaxiality.

[0087] In practical applications, external control systems such as PLCs and microcontrollers preset the target displacement, speed, and output force parameters of the push rod 33 according to actual needs, and send control commands, such as analog or digital commands, to the integrated board 10 of the electric cylinder 100 to start the electric cylinder 100. After receiving the commands, the integrated board 10 outputs precise drive signals, which are transmitted to the hollow cup servo motor through the circuit board 53 and sensor circuit board 43. At the same time, the encoder 52 on the spindle 15 is started to collect the speed and direction signals of the spindle 15 in real time, forming a closed-loop speed control of the hollow cup servo motor itself, ensuring that the hollow cup servo motor starts smoothly and its speed is controllable. After the hollow cup servo motor starts, it outputs high-speed, low-torque rotational power, which is directly transmitted to the two-stage planetary reducer. Through the series transmission of the two-stage planetary gear system, the speed reduction and torque increase are completed according to the preset reduction ratio, converting the high-speed rotational motion into low-speed rotational motion, while amplifying the output torque to provide sufficient power for linear execution.

[0088] The low-speed rotational power, after being reduced and amplified by the planetary reducer, is transmitted to the lead screw 32. The lead screw 32, through a threaded transmission structure, precisely converts its own rotational motion into the linear reciprocating motion of the push rod 33, achieving an efficient conversion from rotational power to linear execution. The motion is smooth and without jamming, making it suitable for the precision pushing needs of micro-scale scenarios.

[0089] Throughout the entire movement of push rod 33, displacement sensor 6 and force control sensor 4 work synchronously to collect running data in real time and transmit it to integrated board 10 through the line to complete dual detection feedback.

[0090] Displacement sensor 6 feedback method: The magnetic grating sensor moves synchronously with the push rod 33. By detecting the periodic alternating magnetic field changes on the magnetic grating, the displacement signal is converted into an electrical signal and transmitted to the integrated board 10 to provide real-time feedback on the current actual position of the push rod 33.

[0091] Force control sensor 4 detection method: The strain gauge 44 is installed at the rear end of the electric cylinder 100. When the push rod 33 contacts the load and generates force, the elastic connector 41 undergoes a small deformation. The strain gauge 44 converts the deformation into a change in resistance, which is then converted into a voltage signal by the Wheatstone bridge and transmitted to the integrated board 10 to provide real-time feedback on the current output force value.

[0092] The integrated board 10 receives the displacement signal from the displacement sensor 6, the force signal from the force control sensor 4, and the signal from the encoder 52, and transmits these three types of signals synchronously to the external control system. The external control system compares the actual displacement and force with the preset parameters in real time, analyzes the deviation through a PID adjustment algorithm (e.g., displacement not reaching the target, force too high or too low), generates adjustment commands, and feeds them back to the integrated board 10.

[0093] According to the adjustment command, the integrated board 10 adjusts the speed, direction, and output torque of the hollow cup servo motor via the circuit board 53, and then synchronously adjusts the movement speed, displacement, and output force of the push rod 33 via the planetary reducer until the push rod 33 reaches the preset target position and force value, completing one precise execution. If continuous operation is required, the above process is repeated to achieve continuous closed-loop control.

[0094] The preferred embodiments of the present invention have been described in detail above, but it should be understood that, if necessary, aspects of the embodiments can be modified to utilize aspects, features, and concepts from various patents, applications, and publications to provide other embodiments.

[0095] In light of the detailed description above, these and other changes can be made to the embodiments. Generally, the terminology used in the claims should not be considered limited to the specific embodiments disclosed in the specification and claims, but should be understood to include all possible embodiments together with the full scope of equivalents enjoyed by these claims.

[0096] 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. An electric cylinder, characterized in that, include: The power module has its main shaft extending along a first direction; A reduction gear module, wherein the reduction gear module is connected to the main shaft of the power module via a transmission connection; The drive module is connected to the reduction gear module in a transmission manner; A force control sensor is installed at the rear end of the power module and is operable to detect external compressive force. An angle sensor, which is connected to the power module, is operable to detect the rotation angle of the spindle; A displacement sensor is installed on the drive module and can be operated to sense the displacement of the drive module.

2. The electric cylinder according to claim 1, characterized in that, The power module includes: Power casing; Rotor magnet, wherein the rotor magnet is arranged in a ring outside the main shaft; Motor windings, which are sleeved around the rotor magnets; The motor core is wrapped around the motor windings, and the motor core and the rotor magnet cooperate to drive the main shaft to rotate; The main shaft extends beyond both ends of the rotor magnet along the first direction; The angle sensor includes: A magnet, which is mounted at the rear end of the spindle; An encoder, which is mounted on the power housing and cooperates with the magnet to detect the rotation angle of the spindle.

3. The electric cylinder according to claim 2, characterized in that, The magnet ring is located at the rear end of the main shaft; The power housing includes: A cylindrical housing surrounds the outside of the motor core; A rear end cover, which is connected to the rear end of the cylindrical shell; The encoder is mounted on the rear cover.

4. The electric cylinder according to claim 3, characterized in that, The rear end of the rear end cover is also provided with a mounting groove; The mounting groove includes a rear section and a front section. The rear section is formed by a recess at the rear end of the rear end cover and opens toward the top surface of the rear end cover. The front section is formed by a portion of the rear section extending to the front end of the rear end cover. The encoder is installed at the front end; The electric cylinder also includes a circuit board, the bottom of which is located at the rear section and connected to the encoder, and the top of which is attached to the top surface of the power housing.

5. The electric cylinder according to claim 3, characterized in that, The force control sensor includes: An elastic connector is installed at the rear end of the rear end cover. The front end face of the elastic connector is provided with a groove communicating with the rear end, and the rear end face is provided with a stud. A sensor circuit board, wherein the sensor circuit board is mounted in the groove and connected to the circuit board; A strain gauge is installed in the groove and connected to the sensor circuit board; A retaining sleeve, which is connected to the stud; A fisheye radial bearing is mounted on the outside of the fixed sleeve.

6. The electric cylinder according to claim 5, characterized in that, The force control sensor also includes a positioning element, which is installed outside the stud and located at the front end of the fixing sleeve.

7. The electric cylinder according to claim 5, characterized in that, The electric cylinder also includes multiple first mounting shafts; The cylindrical shell, the rear end cover, and the elastic connector are respectively mounted on a plurality of first mounting shafts.

8. The electric cylinder according to claim 7, characterized in that, The cylindrical shell and the elastic connector are both rectangular cylindrical; The rear cover has a rectangular cover structure. The four first mounting shafts are respectively mounted at the four corners of the cylindrical housing, the rear end cover, and the elastic connector.

9. The electric cylinder according to claim 1, characterized in that, The reduction gear module is a planetary reduction gear.

10. The electric cylinder according to claim 1, characterized in that, The reduction gear module includes: Reduction gear housing; A gear ring, which is fixedly installed inside the housing of the reduction gear; A primary planetary carrier, which is rotatably mounted within the gear ring; Multiple first-stage planetary gears are mounted at the front end of the first-stage planetary carrier and mesh with the internal teeth of the gear ring. A primary sun gear, which is connected to the front end of the main shaft and located between the primary planetary gears and meshes with the primary planetary gears; The drive module is connected to the front end of the primary planetary carrier.

11. The electric cylinder according to claim 1, characterized in that, The reduction gear module includes: Reduction gear housing; A gear ring, which is fixedly installed inside the housing of the reduction gear; A primary planetary carrier, which is rotatably mounted within the gear ring; Multiple first-stage planetary gears are mounted at the front end of the first-stage planetary carrier and mesh with the internal teeth of the gear ring. A primary sun gear, which is connected to the front end of the main shaft and located between the primary planetary gears and meshes with the primary planetary gears; A secondary planetary carrier, which is rotatably mounted inside the gear ring and located at the front end of the primary planetary carrier; Multiple secondary planetary gears are mounted at the front end of the secondary planetary carrier and mesh with the internal teeth of the gear ring. A second-stage sun gear, which is connected to the rear end of the first-stage planet carrier and meshes with a plurality of second-stage planet gears; The drive module is connected to the front end of the secondary planetary carrier.

12. The electric cylinder according to claim 11, characterized in that, The driving module includes: A drive housing, which is connected to the reduction gear housing; A lead screw, which is installed inside the drive housing and whose rear end is connected to the front end of the secondary planetary carrier; A push rod, which is installed inside the drive housing and threadedly connected to the lead screw.

13. The electric cylinder according to claim 12, characterized in that, The electric cylinder also includes: A top cover that fits over the top of the drive module; An integrated board, which is connected to the top cover; The displacement sensor includes: A magnetic scale, which is mounted on the push rod; A magnetic grating sensor, which is mounted on the integrated board.

14. The electric cylinder according to claim 13, characterized in that, The electric cylinder also includes a mounting base; The mounting base is installed outside the lead screw and has a receiving groove on its top surface; The magnetic scale is installed in the receiving groove.

15. The electric cylinder according to claim 13, characterized in that, The electric cylinder further includes a second mounting shaft, which extends along the first direction and is mounted inside the drive housing; The mounting base is movably mounted on the second mounting shaft.

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