A compact linear electric actuator

Abstract

The present invention discloses a compact linear electric actuator, comprising a housing, an absolute encoder fixed to the housing, an electric operating device, a manual operating device, a manual-electric switching device, and a knob assembly; the electric operating device comprises a motor, a transmission assembly, a nut, and a screw; the motor is fixed to the housing and is transmission-connected to the nut; the screw is linearly movable on the housing; the nut is connected to the screw with a trapezoidal thread; the absolute encoder is mounted on the housing, and the absolute encoder shaft is cooperatively connected to the motor output shaft; the manual operating device comprises a handwheel shaft, a handwheel coupling, and a handwheel bevel gear; the handwheel bevel gear meshes with the external thread of the nut; the manual-electric switching device comprises an elastic return device, a handwheel cover, and a buckle; the handwheel shaft is mounted on the handwheel cover via a sliding bearing, and the buckle is mounted on the handwheel cover. The linear electric actuator of the present invention has the characteristics of small space size, simple structure, high acquisition accuracy, and safety and reliability.

Description

Technical Field

[0001] The present invention relates to an electric actuator, in particular to a compact linear electric actuator with small size requirements, high safety and reliability, and high acquisition accuracy. Background Art

[0002] With the continuous improvement of industrial automation levels, electric actuators, as industrial automation actuators, are increasingly used, and higher requirements are placed on the data acquisition accuracy and safety and reliability of electric actuators. However, the current conventional linear electric actuators have average data acquisition accuracy, and there is a risk of misoperation of buttons and knobs. In addition, they cannot be installed in locations with high space requirements, such as some special occasions in the shipbuilding and HVAC industries.

[0003] In order to solve the limitations of the application of electric actuators in special occasions and improve the safety, reliability and acquisition accuracy of electric actuators, it is necessary to provide a linear electric actuator with small size, high acquisition accuracy, safety and reliability. Summary of the Invention

[0004] In order to solve the problems of existing linear electric actuators being large in size, low in acquisition accuracy, and average in safety and reliability, the present invention provides a new and compact linear electric actuator with a new structure. The actuator has the characteristics of small space size, simple structure, high acquisition accuracy, safety and reliability, and is suitable for batch application.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A compact linear electric actuator comprises a housing, an absolute encoder fixed on the housing for signal acquisition, an electric operating device, a manual operating device, a manual-electric switching device and a knob assembly for switching working modes; the electric operating device comprises a motor, a transmission assembly, a nut and a screw; the motor is fixed on the housing and is connected to the nut through the transmission assembly; the screw is arranged on the housing in a linear motion through a screw bracket; the nut is connected to the screw with a trapezoidal thread to convert rotary motion into linear motion; the absolute encoder is installed on the housing, and the absolute encoder is connected to the screw with a trapezoidal thread to convert rotary motion into linear motion. The encoder shaft is connected with the motor output shaft; the manual operating device includes a handwheel shaft, a handwheel coupling, and a handwheel bevel gear; the external thread of the nut is a bevel gear, and the handwheel bevel gear is meshed with the external thread of the nut; the manual-electric switching device includes an elastic return device, a handwheel cover, and a snap; the handwheel shaft is installed on the handwheel cover through a sliding bearing, and the snap is provided on the handwheel cover; when switching to manual operation, the handwheel shaft cooperates with the handwheel bevel gear through the handwheel coupling and is clamped by the snap; when switching to electric operation, the handwheel coupling is disengaged from the manual bevel gear under the action of the elastic return device.

[0007] The present invention realizes manual-electric switching through a manual-electric switching device, and utilizes a buckle to buckle the handwheel shaft in the manual state, which is convenient for manual operation. At the same time, in the electric state, the rebound of the handwheel connector can be used to disengage the manual bevel gear, avoiding the rotation of the handwheel shaft during electric operation. The simple structure is adopted to effectively and reliably realize manual-electric switching.

[0008] Furthermore, corresponding slots and cylindrical pins are respectively provided at one end of the handwheel coupler near the handwheel bevel gear and on the manual bevel gear; an elastic cylindrical pin is provided at the other end of the handwheel coupler, which is installed on the handwheel shaft through the elastic cylindrical pin; the elastic return device adopts a handwheel compression spring, and the two ends respectively contact the manual bevel gear and the handwheel coupler; when switching to manual operation, the handwheel shaft is pushed, the slot of the handwheel coupler clamps the cylindrical pin of the manual bevel gear, and the handwheel compression spring is in a compressed state.

[0009] One end of the handwheel compression spring contacts the manual coupling, and the spring's elastic restoring force acts on the coupling. When switching to electric operation, the coupling springs open and disengages from the manual helical gear. The other end of the spring can contact a component whose position remains relatively unchanged across various operating modes, such as the housing or the manual helical gear.

[0010] Furthermore, both ends of the handwheel compression spring respectively abut against a gasket and a handwheel connector, and the gasket is installed at a retaining ring of a mounting bearing of the manual helical gear.

[0011] Furthermore, a boss and a through hole are provided on the buckle; the through hole is in the shape of a large circular hole and a small circular hole connected to each other; an annular groove is provided on the outer periphery of the handwheel shaft, and the buckle is arranged in the annular groove of the handwheel shaft through the through hole; when switching to manual operation, the buckle is clamped in the corresponding groove on the handwheel cover through the boss, and the handwheel shaft is clamped in the small circular hole of the buckle; when switching to electric operation, the boss of the buckle is disengaged from the corresponding groove on the handwheel cover, and the handwheel shaft is located at the large circular hole of the buckle.

[0012] Through the design of the snap-fit ​​boss and the through hole, the handwheel shaft can be quickly clamped when switching to manual operation.

[0013] Furthermore, a retaining groove is provided on the screw bracket; a connecting nut is provided on the screw, and through the cooperation between the connecting nut and the retaining groove, the screw moves linearly along the retaining groove.

[0014] The design of the screw bracket and the connecting nut can effectively prevent the screw from rotating.

[0015] Furthermore, the motor is inverted in the box, at a position on one side of the screw, and is fixed to the box through a motor mounting plate; the transmission assembly includes transmission gear 1 and transmission gear 2; transmission gear 2 is engaged with transmission gear 1 and is mounted on the nut through a flat key; the motor output shaft and transmission gear 1 are matched through a keyway to drive transmission gear 1 to rotate, and drive the nut to rotate through transmission gear 2; the absolute encoder is fixed to the box through an encoder mounting plate.

[0016] Furthermore, the knob assembly includes a knob, a knob base, a steel ball, a knob compression spring, a cylindrical pin, and a knob lock; the knob base is fixed to the box body through an upper cover; the steel ball and knob compression spring are installed in the knob base, and the cylindrical pin is provided on the top; three circular bosses are provided on the knob base, which are interference fit with the knob when installed; three circular grooves are provided at the corresponding installation positions of the upper cover, corresponding to different modes (on-site, stop, remote), and the steel ball enters the circular groove at the specified position by rotating the knob; a mounting hole is provided on the knob, and when the knob lock is installed in the mounting hole, the steel ball is pushed into the circular groove by pressing the cylindrical pin, and the knob cannot be rotated.

[0017] The knob is effectively locked by adding a lock to the outside of the knob to avoid accidental operation of the mode switch on site.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The present invention adopts a manual-electric switching device, which uses a handwheel combination with a U-shaped groove in combination with a handwheel compression spring, a buckle, etc. to effectively realize worry-free switching between manual and electric, with a simple structure and small space size.

[0020] 2. The present invention utilizes the space on the side of the linear screw, inverts the motor, compresses the space, and further improves space utilization.

[0021] 3. The present invention adds a padlock to the knob assembly, which is safe and reliable and prevents the knob from being misoperated on site. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a structural diagram of the compact linear electric actuator of the present invention;

[0023] Figure 2 This is a structural diagram of the manual-electric switching device in the compact linear electric actuator of the present invention;

[0024] Figure 3 for Figure 2 Middle buckle structure diagram;

[0025] Figure 4 This is a structural diagram of the knob assembly in the compact linear electric actuator of the present invention.

[0026] In the figure: 1-transmission gear 1, 2-gear box cover, 3-motor mounting plate, 4-upper cover, 5-box, 6-motor, 7-screw bracket, 8-absolute encoder, 9-encoder mounting plate, 10-transmission gear 2, 11-nut, 12-manual bevel gear, 13-screw, 14-connecting nut, 15-elastic cylindrical pin, 16-handwheel shaft, 17-cylindrical pin, 18-handwheel coupling, 19-sliding bearing, 20-handwheel cover, 21-handwheel compression spring, 22-clip, 2201-boss, 23-knob base, 24-knob compression spring, 25-steel ball, 26-magnet, 27-knob, 28-cylindrical pin, 29-knob lock, 30-gasket. DETAILED DESCRIPTION

[0027] The present invention will be further described below with reference to the accompanying drawings.

[0028] like Figures 1 to 4 As shown, the present invention relates to a compact linear electric actuator, including a box body 5, an upper cover 4, a motor 6, a motor mounting plate 3, a transmission gear 1 1, a transmission gear 2 10, a gear box cover 2, a nut 11, a screw 13, a screw bracket 7, a connecting nut 14, a manual bevel gear 12, a handwheel shaft 16, a handwheel connector 18, a sliding bearing 19, a handwheel compression spring 21, a handwheel cover 20, a buckle 22, a gasket 30, a knob 27, a knob base 23, a steel ball 25, a knob compression spring 24, a magnet 26, a cylindrical pin 28, a knob lock 29, an absolute encoder 8, and an encoder mounting plate 9.

[0029] The specific implementation is as follows: the motor 6 is mounted on the housing 5 via the motor mounting plate 3, and the transmission gear 1 and transmission gear 2 10 are mounted on the housing 5 via the gear box cover 2. The output shaft of the motor 6 engages with the keyway of the transmission gear 1, driving the transmission gear 1 to rotate. The transmission gear 1 drives the transmission gear 2 10 to rotate. The transmission gear 2 10 is mounted on the nut 11 via a flat key. The nut 11 is mounted on the housing 5 and is connected to the screw rod 13 with a trapezoidal thread, converting rotational motion into linear motion. The outer side of the nut 11 is a helical gear that meshes with the handwheel helical gear 12. The screw rod bracket 7 is mounted on the housing 5 and has a retaining groove. The connecting nut 14 is connected to the screw rod 13, and the groove of the connecting nut 14 engages with the retaining groove on the screw rod bracket 7, allowing linear motion along the retaining groove to achieve anti-rotation. The knob assembly is mounted on the housing 5 via the upper cover 4. The absolute encoder 8 is mounted on the encoder mounting plate 9, with the encoder shaft engaged with the motor output shaft. The encoder mounting plate 9 is fixed to the gear box cover 2.

[0030] like Figure 2As shown, the manual operating device and the manual-electric switching device include: a manual bevel gear 12, a handwheel shaft 16, a handwheel coupling 18, a sliding bearing 19, a handwheel compression spring 21, a handwheel cover 20, a buckle 22, and a gasket 30; the manual bevel gear 12 is mounted on the housing 5 through a bearing, and a cylindrical pin 17 is installed at one end close to the handwheel coupling 18; the gasket 30 is mounted on the retaining ring of the bearing on one side of the handwheel bevel gear; the handwheel shaft 16 is mounted on the sliding bearing 19 on the handwheel cover 20 Inside, an elastic cylindrical pin 15 is installed near one end of the handwheel coupling 18; the buckle 22 is installed on the handwheel cover 20, which is provided with two U-shaped grooves and fixed with two plug screws; the handwheel coupling 18 is installed on the handwheel shaft 16 through the elastic cylindrical pin; the two ends of the handwheel compression spring 21 respectively contact the gasket 30 and the handwheel coupling 18; the handwheel coupling 18 is provided with a slot; the handwheel shaft 16 is provided with an annular groove on the circumference, and the buckle 22 is sleeved on the annular groove.

[0031] like Figure 3 As shown, the buckle 22 is provided with two bosses 2201 and a through hole, which is formed by two intersecting circular holes, one large and one small. The buckle 22 is also provided with two U-shaped grooves, which are equipped with two plug screws. The buckle can be made of nylon.

[0032] When switching to manual operation, push the handwheel shaft 16, and the slot in the handwheel coupling 18 will be stuck in the cylindrical pin on the manual bevel gear 12. At the same time, pull the buckle 22 to one side by hand, so that the annular groove on the handwheel shaft 16 is stuck in the smaller circular hole in the buckle 22, and the two small bosses in the buckle 22 are stuck in the corresponding grooves on the handwheel cover 20. At this time, rotate the handwheel shaft 16, and the handwheel shaft 16 drives the handwheel coupling 18 to rotate through the elastic cylindrical pin. The handwheel coupling 18 drives the manual bevel gear 12 to rotate through the cylindrical pin. The manual bevel gear 12 engages with the nut 11 for transmission to realize manual operation.

[0033] When switching to electric operation, pull up the buckle 22 by hand to separate the two small bosses on it from the handwheel cover 20, and pull the buckle 22 to the other side so that the annular groove on the handwheel shaft 16 moves into the larger circular hole in the buckle (22). At this time, the handwheel coupling 18 rebounds under the action of the handwheel compression spring 21, and the handwheel coupling 18 is disengaged from the manual bevel gear 12. During electric operation, the handwheel shaft 16 does not rotate, and electric operation is achieved.

[0034] like Figure 4As shown, the knob assembly includes a knob 27, a knob base 23, a steel ball 25, a knob compression spring 24, a magnet 26, a cylindrical pin 28, and a knob lock 29; the knob base 23 is provided with three circular bosses, which are interference fit with the knob 27 when installed to achieve integrated installation; the steel ball 25 and the knob compression spring 24 are installed in the knob base, and a cylindrical pin 28 is provided on the top; the upper cover 4 is provided with three circular grooves corresponding to the installation position, which correspond to the three modes of local, stop, and remote respectively (the specific mode can be implemented using existing conventional technology), and the knob 27 is rotated to move the steel ball 25 to the groove at the specified position to achieve switching between the three modes; the knob 27 is provided with a hole for installing the knob lock 29. After the knob lock 29 is installed, it will press against the cylindrical pin 28, thereby locking the steel ball 25 in the circular groove. At this time, the knob 27 cannot be rotated, avoiding on-site misoperation and switching the mode; the inner diameter of the knob compression spring is larger than the outer diameter of the cylindrical pin and slightly smaller than the diameter of the steel ball.

[0035] The above description is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements can be made without departing from the principles of the present invention. These improvements should also be regarded as the scope of protection of the present invention.

Claims

1. A compact linear electric actuator comprising a housing, an absolute encoder fixed to the housing for signal acquisition, an electric operating device, a manual operating device, a manual-electric switching device, and a knob assembly for switching working modes; characterized in that: The electric operating device comprises: a motor, a transmission assembly, a nut, and a screw; the motor is fixedly mounted on the box body and is connected to the nut through the transmission assembly; the screw is arranged on the box body for linear motion through a screw bracket; the nut is connected to the screw trapezoidal thread to convert rotary motion into linear motion; the absolute encoder is mounted on the box body, and the absolute encoder shaft is matched with the motor output shaft; the manual operating device comprises a handwheel shaft, a handwheel coupling, and a handwheel helical gear; the external thread of the nut is a helical gear, and the handwheel helical gear is meshed with the external thread of the nut; the manual-electric switching device comprises an elastic return device, a handwheel cover, and a snap; the handwheel shaft is mounted on the handwheel cover through a sliding bearing, and the snap is arranged on the handwheel cover; when switching to manual operation, the handwheel shaft cooperates with the handwheel helical gear through the handwheel coupling and is clamped by the snap; when switching to electric operation, the handwheel coupling is under the action of the elastic return device The cam is engaged with the handwheel shaft and is disengaged from the manual bevel gear; one end of the handwheel engagement member near the handwheel bevel gear and the manual bevel gear are respectively provided with a corresponding groove and a cylindrical pin; the other end of the handwheel engagement member is provided with an elastic cylindrical pin, which is installed on the handwheel shaft through the elastic cylindrical pin; the elastic return device adopts a handwheel compression spring, and when manual operation is switched, the groove of the handwheel engagement member clamps the cylindrical pin of the manual bevel gear, the handwheel compression spring is in a compressed state, and one end of the handwheel compression spring contacts the handwheel engagement member; the buckle is provided with a boss and a through hole; the through hole is in the shape of a large circular hole and a small circular hole connected to each other; the outer periphery of the handwheel shaft is provided with an annular groove, and the buckle is arranged in the annular groove of the handwheel shaft through the through hole; when manual operation is switched, the buckle is clamped in the corresponding groove on the handwheel cover through the boss, and the handwheel shaft is clamped in the small circular hole of the buckle; when electric operation is switched, the boss of the buckle disengages from the corresponding groove on the handwheel cover, and the handwheel shaft is located at the large circular hole of the buckle.

2. A compact linear electric actuator according to claim 1, characterized in that: The manual helical gear is mounted on the box body through a bearing, a gasket is provided at the retaining ring of the bearing, and two ends of the handwheel compression spring respectively contact the gasket and the handwheel connector.

3. A compact linear electric actuator according to claim 1, characterized in that: The screw support is provided with a retaining groove; the screw is provided with a connecting nut, and the screw moves linearly along the retaining groove through the cooperation between the connecting nut and the retaining groove.

4. A compact linear electric actuator according to claim 1, characterized in that: The motor is inverted in the box, at a position on one side of the screw, and is fixed to the box through a motor mounting plate; the transmission assembly includes transmission gear 1 and transmission gear 2; transmission gear 2 is engaged with transmission gear 1 and is mounted on the nut through a flat key; the motor output shaft and transmission gear 1 are matched through a keyway, driving transmission gear 1 to rotate, and driving the nut to rotate through transmission gear 2; the absolute encoder is fixed to the box through an encoder mounting plate.

5. A compact linear electric actuator according to claim 1, characterized in that: The knob assembly includes a knob, a knob base, a steel ball, a knob compression spring, a cylindrical pin, and a knob lock; the knob base is fixed to the box body through an upper cover; the steel ball and knob compression spring are installed in the knob base, and the cylindrical pin is provided on the top; three circular bosses are provided on the knob base, which have an interference fit with the knob when installed; three circular grooves are provided at the corresponding installation positions of the upper cover, corresponding to different modes respectively, and the steel ball enters the circular groove at the specified position by rotating the knob; a mounting hole is provided on the knob, and when the knob lock is installed in the mounting hole, the steel ball is pushed into the circular groove by pressing the cylindrical pin, and the knob cannot be rotated.

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