Electric cylinder

Abstract

The utility model belongs to linear drive equipment technical field, concretely relates to a kind of electric cylinder.The electric cylinder includes shell assembly (1), transmission assembly (2), speed reducer (3), motor (4) and linear movement mechanism (5).The utility model is connected by the rotation axis (41) of motor (4) through the driving wheel (21) of transmission assembly (2) and the speed reducer (3) of another side, and utilizes the characteristics of speed reducer (3) same side input and output, realizes the nesting and overlap of motor (4), driving wheel (21) and speed reducer (3) in axial space.The structure breaks the axial series layout of traditional component, significantly shortens the axial dimension of electric cylinder, improves the compactness of structure, especially applicable to the occasion of limited installation space.

Description

Technical Field

[0001] This utility model belongs to the technical field of linear drive equipment, specifically relating to an electric cylinder. Background Technology

[0002] With the intelligent development of transportation vehicles and industrial automation equipment, traditional hydraulic or pneumatic braking systems are gradually being replaced by electromechanical braking systems due to their complex structure, high maintenance costs, and poor environmental friendliness. The core of an electromechanical braking system is the brake drive mechanism. Traditional brake drive mechanisms typically use a motor to drive a reduction gear mechanism, which in turn drives a linear actuator (such as a lead screw mechanism) to generate thrust.

[0003] The core component of existing brake drive mechanisms is the electric cylinder. Folding-back electric cylinders use gears or synchronous belts to connect the motor shaft and lead screw shaft in parallel, making them suitable for applications with limited installation space. However, in existing folding-back electric cylinder technology, to meet the demand for high thrust, a reducer is usually added between the motor and the transmission assembly to increase torque. The common existing structural layout typically involves arranging the motor, reducer, and drive pulley (such as a drive gear or pulley) in series axially. That is, the motor's output shaft is connected to the reducer's input end, and the reducer's output end is then connected to the drive pulley.

[0004] The motor, reducer, and drive wheel are simply stacked axially, resulting in a relatively long total axial length of the electric cylinder on the motor side. In applications where installation space is extremely sensitive, such as automotive wheel-side brakes, excessive axial length can cause interference and make installation difficult. Furthermore, an excessively long drive-end assembly may cause the overall center of gravity of the electric cylinder to shift, affecting installation stability and vibration resistance. Utility Model Content

[0005] In view of this, the present invention proposes an electric cylinder that aims to shorten the axial dimension of the electric cylinder while ensuring the output torque, thereby achieving a higher degree of integration and lightweighting.

[0006] The electric cylinder provided by this utility model includes a housing assembly, a transmission assembly, a reducer, a motor, and a linear movement mechanism. The transmission assembly includes a driving wheel and a driven wheel rotatably mounted on the housing assembly, with their axes parallel. The reducer is located on one side of the driving wheel, with its input and output ends located on the same axial end. The output end is coaxially arranged around the outside of the input end and connected to the driving wheel. The motor is located on the other side of the driving wheel, with its shaft coaxially passing through the driving wheel and connected to the input end of the reducer. The linear movement mechanism includes a lead screw, one end of which is coaxially connected to the driven wheel.

[0007] In a preferred embodiment of the electric cylinder provided by this utility model, the housing assembly includes a base and an end seat. The base has a first mounting groove and a mounting cylinder inside. The reducer is installed in the first mounting groove. A first bearing is provided in the mounting cylinder. The inner ring of the first bearing is connected to the end of the lead screw. The end seat is connected to the top surface of the base and forms a mounting cavity with the base. The drive wheel and the driven wheel are provided in the mounting cavity.

[0008] In a preferred embodiment of the electric cylinder provided by this utility model, the reducer is a planetary reducer, which is provided with a sun gear, an internal gear ring, and a planet carrier. The input end of the reducer is formed at one shaft end of the sun gear, and the output end of the reducer is formed at one shaft end of the planet carrier. The first mounting groove is formed at the bottom of the base, and an annular step is formed on the inner sidewall of the first mounting groove. One end of the internal gear ring is supported on the annular step. The housing assembly also includes a pressure cap, the inner end of which is supported at the other end of the internal gear ring. Bolts pass through the pressure cap and the internal gear ring and are connected to the annular step.

[0009] In a preferred embodiment of the electric cylinder provided by this utility model, the electric cylinder further includes a second bearing, a third bearing, and a fourth bearing. The second bearing is connected between the outer side of the first shaft end of the planetary carrier and the pressure cap; the third bearing is connected between the inner side of the first shaft end of the planetary carrier and the other shaft end of the sun gear of the reducer; and the fourth bearing is connected between the outer side of the second shaft end of the planetary carrier and the base. The end face of the second end of the planetary carrier is connected to the end face of the drive gear by bolts.

[0010] In a preferred embodiment of the electric cylinder provided by this utility model, a second mounting groove is further formed within the base, and the electric cylinder further includes a pressure sensor, a pressure ring, and a thrust bearing. The inner hole of the pressure sensor is fitted onto the outside of the mounting cylinder, and it is itself disposed within the second mounting groove. The pressure ring is connected to the top of the base to axially press the pressure sensor into the second mounting groove. The thrust bearing is connected to one end of the driven wheel, and the other end is in close contact with the pressure sensor to transmit the axial thrust of the lead screw to the pressure sensor.

[0011] In a preferred embodiment of the electric cylinder provided by this utility model, the rotating shaft is formed with a cylindrical portion, which is connected to the shaft hole of the inner rotor of the motor. The cylindrical portion has an opening facing away from the drive wheel. The electric cylinder also includes a housing and a brake. The bottom end of the housing is connected to the end seat, and its inner wall is connected to the outer stator of the motor. One end of the brake is connected to the inner side of the cylindrical portion, and the other end is connected to the housing, and the entire brake is located within the axial height range of the outer stator.

[0012] In a preferred embodiment of the electric cylinder provided by this utility model, the electric cylinder further includes an end cover and an encoder. The end cover is connected to one shaft end of the housing and forms an electrical cavity between it and the shaft end of the housing; the encoder includes a reading head and a code disk, and is disposed within the electrical cavity. The code disk is connected to one shaft end of the motor, and the reading head is connected to the inner side of the end cover.

[0013] In a preferred embodiment of the electric cylinder provided by this utility model, the linear movement mechanism further includes a cylinder body, a slide rod, and a lead screw sleeve. One end of the cylinder body is connected to the top surface of the end seat, and its inner wall has a first limiting portion parallel to the axial direction. The outer wall of the slide rod has a second limiting portion, which slides and limits the movement of the second limiting portion in a limiting engagement with the first limiting portion. The inner side of the lead screw sleeve is threadedly engaged with the lead screw, and its outer wall is connected to the inside of the slide rod.

[0014] In a preferred embodiment of the electric cylinder provided by this utility model, the reducer is a harmonic reducer, the input end of the reducer is formed on one shaft end of the wave generator, and the output end of the reducer is formed on one shaft end of the flexible wheel.

[0015] In a preferred embodiment of the electric cylinder provided by this utility model, the electric cylinder is equipped with an encoder and a pressure sensor. The encoder is configured to detect the rotation parameters of the motor, and the pressure sensor is configured to detect the thrust of the lead screw. The electric cylinder also includes a drive controller, which is electrically connected to the motor and signal-connected to the encoder and the pressure sensor.

[0016] This invention connects the motor shaft through the drive wheel to the reducer on the other side, and utilizes the reducer's same-side input / output characteristic to achieve axial nesting and overlap of the motor, drive wheel, and reducer. This structure breaks away from the traditional axial series layout of components, significantly shortens the axial dimension of the electric cylinder, improves the structural compactness, and is particularly suitable for applications with limited installation space. Attached Figure Description

[0017] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can more clearly understand the above and other features and advantages of the present invention, in which:

[0018] Figure 1 This is a schematic diagram of the external structure of the electric cylinder in this embodiment.

[0019] Figure 2 This is a cross-sectional structural diagram of the electric cylinder in this embodiment.

[0020] Figure 3This is a schematic diagram of the internal structure of the electric cylinder in this embodiment.

[0021] Figure 4 This is a schematic diagram of the base structure of the electric cylinder in this embodiment.

[0022] Figure 5 This is a schematic diagram of the installation structure of the transmission assembly of the electric cylinder in this embodiment.

[0023] Figure 6 This is a schematic diagram of the assembly structure of the reducer of the electric cylinder in this embodiment.

[0024] Figure 7 This is an exploded view of the linear movement mechanism of the electric cylinder in this embodiment.

[0025] Figure 8 This is a schematic diagram showing the assembly relationship between the motor and the brake of the electric cylinder in this embodiment.

[0026] The reference numerals in the attached figures are as follows:

[0027] 1-Housing assembly; 11-Base; 111-First mounting slot; 112-Second mounting slot; 1121-Mounting cylinder; 12-End seat; 13-Gland; 14-Pressure ring; 15-Housing; 16-End cover; 17-Adapter flange;

[0028] 2-Transmission assembly; 21-Driving wheel; 22-Driven wheel;

[0029] 3-Reducer; 301-Input end; 302-Output end; 31-Sun gear; 32-Internal gear ring; 33-Planet carrier;

[0030] 4-Motor; 41-Shaft; 411-Cylinder; 42-Inner rotor; 43-Outer stator;

[0031] 5-Linear movement mechanism; 51-Lead screw; 52-Cylinder body; 521-First limiting part; 53-Slide rod; 531-Second limiting part; 54-Lead nut sleeve;

[0032] 61-First bearing; 62-Second bearing; 63-Third bearing; 64-Fourth bearing; 65-Thrust bearing;

[0033] 7-Pressure sensor; 8-Brake; 9-Encoder. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0035] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "connection" and "setup" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0036] Furthermore, it should be understood in the description of this application that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not 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.

[0037] This embodiment provides an electric cylinder, primarily used in space-constrained applications requiring high thrust, such as electronic mechanical braking systems (EMBs) in vehicles. This electric cylinder employs a highly integrated parallel-axis layout in its overall design. (Refer to...) Figure 1 The main body of the equipment is supported by the housing assembly 1, which mainly includes a base 11 and an end seat 12.

[0038] The base 11, as the main load-bearing component, has specific internal mounting space. Specifically, combined with... Figures 2 to 4 The base 11 has a first mounting groove 111 and a mounting cylinder 1121 inside. The first mounting groove 111 is located at the bottom of the base 11 and is used to accommodate the reducer 3; the mounting cylinder 1121 is used to support the end of the lead screw 51. The end seat 12 is connected to the top surface of the base 11, and the two are fastened together to form a closed or semi-closed mounting cavity. This mounting cavity is mainly used to accommodate the transmission assembly 2 (i.e., the driving wheel 21 and the driven wheel 22). The housing 15 of the motor 4 is connected to the end seat 12. From the outside, the motor 4, the end seat 12, and the base 11 are arranged axially in sequence, with a compact structure.

[0039] The core of this embodiment lies in its unique "through-shaft" transmission design. Combined with... Figure 3 and Figure 5 The transmission assembly 2 includes a driving pulley 21 and a driven pulley 22 arranged parallel to each other within the mounting cavity. Although the driving pulley 21 and driven pulley 22 in the attached drawings are illustrated using gear meshing as an example, the driving pulley 21 and driven pulley 22 can also be selected as synchronous pulleys to form a belt drive. The axes of the driving pulley 21 and driven pulley 22 are parallel.

[0040] Combination Figure 3 The motor 4 is located on one side of the drive wheel 21 (e.g., above), and the reducer 3 is located on the other side of the drive wheel 21 (e.g., below, i.e., inside the base 11). The shaft 41 of the motor 4 is designed to be relatively long. It passes coaxially through the center hole of the drive wheel 21 and extends directly to the reducer 3 below, and connects to the input end 301 of the reducer 3.

[0041] In this preferred embodiment, combined with Figure 6 The reducer 3 is a planetary reducer. The input end 301 and the output end 302 of the reducer 3 are located on the same axial end side of the reducer 3 itself (i.e., the side facing the driving gear 21). The input end 301 of the reducer 3 is one shaft end of the sun gear 31, which is directly connected to the rotating shaft 41 of the motor 4 passing through the driving gear 21. The output end 302 of the reducer 3 is one shaft end of the planet carrier 33, and this output end 302 is coaxially arranged around the outside of the input end 301.

[0042] Continue to refer to Figure 1 and Figure 2 An annular step is formed on the inner wall of the first mounting groove 111 of the base 11. One end of the internal gear ring 32 of the planetary reducer is supported on this annular step, which not only serves as an axial positioning function but also restricts the rotation of the internal gear ring 32. For further fixation, a pressure cap 13 is provided, with the inner end of the pressure cap 13 abutting against the other end of the internal gear ring 32. Bolts are passed through the pressure cap 13 and the internal gear ring 32 and locked onto the annular step, thereby firmly locking the internal gear ring 32 of the reducer 3 into the base 11.

[0043] The power output path is as follows: the motor 4 shaft 41 rotates → drives the sun gear 31 → the planet gears revolve within the fixed internal gear ring 32 → drives the planet carrier 33 to rotate.

[0044] Continue to refer to Figure 2To ensure the stability of the planetary carrier 33's rotation, multiple sets of bearings are installed. The second bearing 62 is located between the outer side of the first shaft end of the planetary carrier 33 and the pressure cover 13. The third bearing 63 is located between the inner side of the first shaft end of the planetary carrier 33 and the sun gear 31, ensuring input and output coaxiality. The fourth bearing 64 is located between the second shaft end of the planetary carrier 33 (the end opposite to the driving gear 21) and the interior of the base 11. Furthermore, the output end 302 of the planetary carrier 33 is rigidly connected to the end face of the driving gear 21 by bolts. Therefore, the reduced torque is directly transmitted to the driving gear 21. The driving gear 21 drives the driven gear 22 to rotate, and the driven gear 22 is responsible for driving the linear motion mechanism 5.

[0045] This embodiment also provides a modified implementation based on a harmonic reducer. In certain scenarios with extremely high precision requirements or more limited axial space, the harmonic reducer 3 can be used. In this case, the wave generator of the harmonic reducer 3 serves as the input end 301, and its shaft hole is connected to the motor 4 shaft 41 passing through the drive wheel 21. The flexible wheel of the harmonic reducer 3 serves as the output end 302, and its end is connected to the drive wheel 21. Furthermore, the rigid wheel of the harmonic reducer 3 is fixed within the first mounting groove 111 of the base 11.

[0046] In this embodiment, the motor 4 drives the wave generator to rotate, forcing the flex wheel to undergo elastic deformation and mesh with the rigid wheel through misaligned teeth, thereby driving the flex wheel to output low-speed, high-torque output. The harmonic reducer 3 has advantages such as a large single-stage reduction ratio, no backlash, and fewer parts, which can further improve the positioning accuracy of the electric cylinder.

[0047] Continue to refer to Figure 2 and Figure 3 One end of the lead screw 51 is coaxially fixed to the center of the driven wheel 22 and rotates together with the driven wheel 22. The end of the lead screw 51 is supported in the mounting sleeve 1121 of the base 11 by the first bearing 61 to bear the radial load.

[0048] Combination Figure 7 A cylinder 52 is connected to the top surface of the end seat 12. A first limiting part 521 parallel to the axial direction is machined on the inner wall of the cylinder 52. A lead screw nut 54 is fitted onto the lead screw 51, with its internal thread engaging with the lead screw 51, and a slide rod 53 connected to its external side. A second limiting part 531 is provided on the outer wall of the slide rod 53, engaging with the first limiting part 521 of the cylinder 52. When the lead screw 51 rotates, the slide rod 53 cannot rotate due to the limitation of the limiting part; the lead screw nut 54 and the slide rod 53 can only extend or retract axially, thereby achieving the output of thrust.

[0049] This embodiment connects the motor 4 to the reducer 3 by having the shaft 41 of the motor 4 pass through the drive wheel 21, so that the motor 4 and the reducer 3 are distributed on both sides of the gear plane, which greatly shortens the axial dimension of the electric cylinder; at the same time, the design of the reducer 3 with input and output on the same side makes the power transmission circuit extremely short, with good rigidity and compact structure.

[0050] In addition, continue to refer to Figure 1 and Figure 2 The housing assembly 1 may also be provided with an adapter flange 17, the central hole of which allows one end of the cylinder body 52 to pass through and connect to the cylinder body 52, and the adapter flange 17 is also connected to the mounting seat of the brake device.

[0051] In a preferred embodiment of the electric cylinder in this example, refer to... Figure 2 and Figure 3 This section describes the force control structure of the integrated pressure sensor 7. Inside the base 11, in addition to the aforementioned mounting cylinder 1121, a second mounting groove 112 is formed. The pressure sensor 7 is an annular pressure sensor, its inner hole fitting around the outside of the mounting cylinder 1121, and the entire sensor is placed at the bottom of the second mounting groove 112. A pressure ring 14 is used to connect to the top of the base 11; for example, the pressure ring 14 can be screwed into the base 11 by threads, or the pressure ring 14 can be bolted to the base 11, pre-tightening or fixing the pressure sensor 7 axially within the groove. A thrust bearing 65 is provided on the shaft end of the driven wheel 22 facing the base 11. One side of the thrust bearing 65 is connected to the driven wheel 22, and the other side is in close contact with the force-bearing surface of the pressure sensor 7.

[0052] When the electric cylinder outputs thrust, the lead screw 51 experiences a significant reverse axial force. This force is transmitted to the driven wheel 22 via the lead screw 51, and then the driven wheel 22 directly presses this force onto the pressure sensor 7 via the thrust bearing 65. Thus, the electric cylinder in this embodiment further enhances force feedback functionality, making it particularly suitable for braking systems. It achieves direct, real-time detection of the output thrust. Compared to estimating torque through motor current, this direct measurement method eliminates errors caused by transmission efficiency fluctuations, resulting in higher control precision and better safety.

[0053] This embodiment focuses on the internal details of motor 4 and the detection feedback component, aiming to further reduce the size of the electric cylinder. Combined with Figure 8 The motor 4 can be configured with a built-in brake 8. Specifically, the shaft 41 of the motor 4 is not a solid long rod, but rather forms a cylindrical portion 411 with a large diameter. This cylindrical portion 411 is connected to the shaft hole of the rotor 42 inside the motor 4. The cylindrical portion 411 has an opening facing away from the drive wheel 21, forming an internal receiving space.

[0054] The electromagnetic brake 8 is installed in the space inside the cylinder 411. One end of the brake 8 is connected to the inside of the cylinder 411, and the other end is connected to the housing 15. The outer stator 43 of the motor 4 is fixed to the inner wall of the housing 15, and the bottom end of the housing 15 is connected to the end seat 12.

[0055] Thus, the electric cylinder of this embodiment has the following spatial advantage: the brake 8 is entirely located within the axial height range of the outer stator 43 (i.e., the brake 8 is "hidden" inside the rotor of the motor 4). This results in the motor 4 having almost no increase in axial length after the addition of the brake 8 function.

[0056] Continue to refer to Figure 2 and Figure 3 An end cover 16 is connected to the top of the housing 15, forming an electrical cavity between the end cover 16 and the housing 15. The encoder 9 includes a reading head and a code disk. The code disk is mounted at the end of the shaft 41 of the motor 4, and the reading head is mounted inside the end cover 16. The encoder 9 is used to detect the speed and angular position of the motor 4 and feed the signal back to the drive controller.

[0057] The control aspects of the electric cylinder in this embodiment include an encoder 9 (for position / speed loop control) integrated at the tail of the motor 4 and a pressure sensor 7 (for force / current loop auxiliary control) integrated in the base 11. The drive controller is electrically connected to the motor 4 and signal-connected to the encoder 9 and the pressure sensor 7.

[0058] The working process of this electric cylinder includes:

[0059] (1) Braking request: The drive controller receives a braking signal from the vehicle.

[0060] (2) Action execution: The controller controls the rotation of the motor 4. After the motor shaft 41 is reduced in speed and torque is increased by the reducer 3, it drives the driving wheel 21 and the driven wheel 22 to rotate, which in turn drives the lead screw 51 to rotate.

[0061] (3) Thrust establishment: The rotation of the lead screw 51 drives the slide bar 53 to extend linearly, eliminating the brake gap and causing the brake pads to press against the brake disc.

[0062] (4) Closed-loop control: Encoder 9 provides real-time feedback on the rotation angle of motor 4 and calculates the moving distance of slide bar 53 to achieve rapid response. When it contacts the brake disc, the actual clamping force signal detected by pressure sensor 7 is fed back to the drive controller. The drive controller fine-tunes the torque of motor 4 based on the difference between the target pressure and the actual pressure to achieve precise braking force control.

[0063] (5) Holding and releasing: When the vehicle is stationary, the brake 8 inside the motor 4 is activated to lock the position of the lead screw 51 and realize the parking function; when it is necessary to release, the motor 4 reverses and the slide bar 53 retracts.

[0064] In summary, the electric cylinder of this embodiment has high rigidity, compactness and force sensing capability, and can provide an electric cylinder for brake drive with fast response speed, high control precision and small size that can be installed in the wheel hub.

[0065] It should be understood that although this specification is described according to various embodiments, not every embodiment or implementation method contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0066] The above descriptions are merely illustrative embodiments of this application and are not intended to limit the scope of the embodiments of this application. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the embodiments of this application should fall within the protection scope of the embodiments of this application.

Claims

1. An electric cylinder, characterized in that, include: Housing assembly (1); The transmission assembly (2) includes a drive wheel (21) and a driven wheel (22) rotatably disposed on the housing assembly (1), the axes of the drive wheel (21) and the driven wheel (22) being parallel; The reducer (3) is located on one side of the drive wheel (21), and its input end (301) and output end (302) are located on the same axial end side of itself. The output end (302) is coaxially arranged around the outside of the input end (301). The output end (302) of the reducer (3) is connected to the drive wheel (21). The motor (4) is located on the other side of the drive wheel (21), and its shaft (41) passes coaxially through the drive wheel (21) and is connected to the input end (301) of the reducer (3); The linear movement mechanism (5) includes a lead screw (51), one end of which is coaxially connected to the driven wheel (22).

2. The electric cylinder according to claim 1, characterized in that, The housing assembly (1) includes: The base (11) has a first mounting groove (111) and a mounting cylinder (1121) inside. The reducer (3) is installed in the first mounting groove (111), and a first bearing (61) is provided in the mounting cylinder (1121). The inner ring of the first bearing (61) is connected to the end of the lead screw (51). An end seat (12) is connected to the top surface of the base (11) and forms a mounting cavity between the base (11) and the base (11), wherein the drive wheel (21) and the driven wheel (22) are disposed in the mounting cavity.

3. The electric cylinder according to claim 2, characterized in that, The reducer (3) is a planetary reducer, which is provided with a sun gear (31), an internal gear ring (32) and a planet carrier (33). The input end (301) of the reducer (3) is formed on one shaft end of the sun gear (31), and the output end (302) of the reducer (3) is formed on one shaft end of the planet carrier (33). The first mounting groove (111) is formed at the bottom of the base (11), and an annular step is formed on the inner sidewall of the first mounting groove (111). One end of the internal gear ring (32) is supported on the annular step. The housing assembly (1) also includes a gland (13) whose inner end is supported at the other end of the internal gear ring (32), and bolts pass through the gland (13) and the internal gear ring (32) to connect to the annular step.

4. The electric cylinder according to claim 3, characterized in that, Also includes: A second bearing (62) is connected between the outer side of the first shaft end of the planetary carrier (33) and the pressure cap (13); The third bearing (63) is connected between the inner side of the first shaft end of the planet carrier (33) and the other shaft end of the sun gear (31) of the reducer (3); A fourth bearing (64) is connected between the outer side of the second shaft end of the planetary carrier (33) and the base (11); The end face of the second end of the planetary carrier (33) is connected to the end face of the drive wheel (21) by bolts.

5. The electric cylinder according to claim 2, characterized in that, A second mounting groove (112) is also formed within the base (11), and the electric cylinder further includes: The pressure sensor (7) has its inner hole fitted outside the mounting cylinder (1121) and is itself located in the second mounting groove (112); A pressure ring (14) is attached to the top of the base (11) to press the pressure sensor (7) axially into the second mounting groove (112); A thrust bearing (65) is connected to one end of the driven wheel (22) and the other end is in close contact with the pressure sensor (7) to transmit the axial thrust of the lead screw (51) to the pressure sensor (7).

6. The electric cylinder according to claim 2, characterized in that, The rotating shaft (41) has a cylindrical portion (411) connected to the shaft hole of the inner rotor (42) of the motor (4). The cylindrical portion (411) has an opening facing away from the drive wheel (21). The electric cylinder also includes: The housing (15) has its bottom end connected to the end seat (12) and its inner side wall connected to the outer stator (43) of the motor (4); The brake (8) is connected at one end to the inner side of the cylinder (411) and at the other end to the housing (15), and its entire body is located within the axial height range of the outer stator (43).

7. The electric cylinder according to claim 6, characterized in that, Also includes: An end cap (16) is connected to one end of the housing (15) and forms an electrical cavity between the end cap (16) and the end of the housing (15). An encoder (9) comprising a reading head and a code disk is disposed in the electrical cavity, the code disk being connected to one shaft end of the motor (4), and the reading head being connected to the inside of the end cover (16).

8. The electric cylinder according to claim 2, characterized in that, The linear movement mechanism (5) further includes: The cylinder body (52) has one end connected to the top surface of the end seat (12), and its inner wall has a first limiting part (521) parallel to the axial direction. The slide bar (53) has a second limiting part (531) on its outer wall, and the second limiting part (531) slides and limits the first limiting part (521). The inner side of the nut sleeve (54) is threadedly engaged with the lead screw (51), and its outer wall is connected to the slide rod (53).

9. The electric cylinder according to claim 1, characterized in that, The reducer (3) is a harmonic reducer. The input end (301) of the reducer (3) is formed on one shaft end of the wave generator, and the output end (302) of the reducer (3) is formed on one shaft end of the flex wheel.

10. The electric cylinder according to claim 1, characterized in that, The electric cylinder is equipped with an encoder (9) and a pressure sensor (7). The encoder (9) is configured to detect the rotation parameters of the motor (4), and the pressure sensor (7) is configured to detect the thrust of the lead screw (51). The electric cylinder also includes: The drive controller is electrically connected to the motor (4) and signal-connected to the encoder (9) and the pressure sensor (7).

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