linear actuator

Abstract

The present disclosure provides a linear actuator, comprising a driving mechanism, a main worm gear, a main screw rod, a speed reduction mechanism and a distance adjustment module. The driving mechanism comprises a worm shaft. The main worm gear is engaged with the worm shaft. The main screw rod is rotationally connected with the main worm gear. The speed reduction mechanism comprises a speed reduction worm gear, a bevel gear and a driven gear. The speed reduction worm gear is rotationally connected with the main worm gear, and comprises external threads. The bevel gear is sleeved outside the worm shaft and is not rotationally connected with the worm shaft, and is engaged with the speed reduction worm gear. The driven gear is engaged with the bevel gear. The distance adjustment module comprises a cam and a micro switch. The cam is driven to rotate by the driven gear. The micro switch corresponds to the cam. The worm shaft drives the main worm gear, which in turn drives the speed reduction worm gear and the main screw rod to rotate, so that the speed reduction worm gear drives the bevel gear to drive the driven gear. Thus, the volume of the linear actuator is reduced.

Description

Technical Field

[0001] This disclosure relates to an actuator, and more particularly to a linear actuator having a main screw. Background Technology

[0002] Linear actuators are widely used in daily life, such as in electric chairs, height-adjustable desks, treadmills, folding beds, furniture, and lifting mechanisms, for position adjustment.

[0003] A linear actuator typically includes a drive mechanism, a main worm gear, a main screw, a reduction mechanism, and a pitch adjustment module. The reduction mechanism reduces the rotational speed of the main worm gear before transmitting it to the pitch adjustment module, which calculates the number of rotations of the main worm gear and automatically stops the motor at a preset distance. Consequently, linear actuators have numerous components, which is detrimental to miniaturization of the overall size.

[0004] In view of this, improving the structure of linear actuators to effectively reduce their size has become the goal of relevant manufacturers. Utility Model Content

[0005] To address the aforementioned issues, this disclosure provides a linear actuator that, through structural configuration, effectively arranges the space for internal components, thereby achieving a reduction in size.

[0006] According to one embodiment of this disclosure, a linear actuator is provided, comprising a drive mechanism, a main worm gear, a main screw, a reduction mechanism, and a pitch adjustment module. The drive mechanism includes a worm shaft. The main worm gear meshes with the worm shaft. The main screw is coaxially arranged with the main worm gear and rotates in conjunction with it. The reduction mechanism includes a reduction worm gear, a bevel gear, and a driven gear. The reduction worm gear is coaxially arranged below the main worm gear and rotates in conjunction with it, and includes an external thread. The bevel gear is sleeved on the outside of the worm shaft but does not rotate in conjunction with it. The bevel gear includes multiple grooves, which are arranged around an inclined surface of the bevel gear. The bevel gear meshes with the reduction worm gear, such that the external thread protrudes into one of the multiple grooves. The driven gear is orthogonal to the bevel gear and meshes with it. The pitch adjustment module includes a cam and a micro switch. The cam is driven to rotate by the driven gear. The micro switch corresponds to the cam. The worm shaft drives the main worm wheel, which in turn drives the reduction worm wheel and the main screw to rotate. This causes the reduction worm wheel to drive the bevel gear, which in turn drives the driven gear. The cam triggers the micro switch.

[0007] According to the linear actuator of the aforementioned embodiment, the worm shaft may include a threaded section and a connecting section connected to each other, the threaded section engaging with the main worm wheel, and the connecting section on which a bevel gear is fitted.

[0008] According to the linear actuator of the aforementioned embodiment, the main worm gear may include a wheel body and a fitting tube coaxially connected, the wheel body engaging with the worm shaft, and the fitting tube fitting with the reduction worm gear.

[0009] The linear actuator according to the aforementioned embodiment may further include a housing, which includes a first housing, a second housing, and a tail cover. The first housing and the second housing are assembled to form an accommodating space for accommodating the worm shaft, the main worm wheel, the reduction mechanism, and the pitch adjustment module therein. The tail cover is integrally connected to the first housing, and the fitting tube is connected to the side of the wheel body away from the tail cover.

[0010] According to the linear actuator of the aforementioned embodiment, the housing may further include a wire-passing groove formed in the second housing for a wire to pass through a limiting position.

[0011] According to the linear actuator of the aforementioned embodiment, the reduction worm gear may include an annular body that tapers towards the wheel body into a cone shape and includes an outer conical surface, with an external thread disposed on the outer conical surface.

[0012] According to the linear actuator of the aforementioned embodiment, the reduction mechanism may further include an elastic element, which is sleeved on the connecting section and is farther away from the threaded section than the bevel gear.

[0013] According to another embodiment of this disclosure, a linear actuator is provided, comprising a housing, a drive mechanism, a main worm gear, a main screw, a reduction mechanism, and a pitch adjustment module. The drive mechanism includes a worm shaft housed in the housing, the main worm gear meshing with the worm shaft, and the main screw coaxially arranged and rotating with the main worm gear, the main screw protruding from the housing. The reduction mechanism includes a reduction worm gear, a bevel gear, and a driven gear. The reduction worm gear is coaxially arranged and rotating with the main worm gear, and includes an external thread. The bevel gear is sleeved on the outside of the worm shaft but not rotating with it, and meshes with the reduction worm gear. The driven gear is orthogonal to and meshes with the bevel gear. The pitch adjustment module includes a cam and a micro switch. The cam is rotated by the driven gear. The micro switch corresponds to the cam. The worm shaft drives the main worm wheel, which in turn drives the reduction worm wheel and the main screw to rotate. This causes the reduction worm wheel to drive the bevel gear, which in turn drives the driven gear. The cam triggers the micro switch.

[0014] According to the linear actuator of the aforementioned embodiment, the main worm gear may include a wheel body and a fitting tube coaxially connected. The wheel body is engaged with the worm shaft, and the fitting tube is fitted with the reduction worm gear. The reduction worm gear includes an annular body that tapers towards the wheel body into a cone shape and includes an outer conical surface. An external thread is provided on the outer conical surface.

[0015] The linear actuator according to the aforementioned embodiment may further include a stabilizing bushing, the housing including an opening and a slot, the opening for the main screw to extend outward, the slot communicating with the opening, and the stabilizing bushing sleeve fitted onto the main screw and located in the slot. Attached Figure Description

[0016] Figure 1A perspective view of a linear actuator according to an embodiment of the present disclosure is shown.

[0017] Figure 2 Draw Figure 1 Partial exploded view of the linear actuator in the embodiment;

[0018] Figure 3 Draw Figure 1 A partial top view of the linear actuator in the embodiment; and

[0019] Figure 4 Draw Figure 1 A partial cross-sectional schematic diagram of the linear actuator in the embodiment.

[0020] The reference numerals in the attached figures are explained as follows:

[0021] 10: Linear actuator

[0022] 100: Drive mechanism

[0023] 110: Worm shaft

[0024] 111: Threaded section

[0025] 112: Connecting segment

[0026] 120: Motor stator

[0027] 130: Motor rotor

[0028] 200: Main worm gear

[0029] 210: Wheel

[0030] 220: Chimeric tube

[0031] 230: Connecting shaft

[0032] 300: Reduction Mechanism

[0033] 310: Reduction worm gear

[0034] 311: External thread

[0035] 312: Ring body

[0036] 320: Bevel gear

[0037] 321: Groove

[0038] 322: Umbrella Top

[0039] 323: Inner sleeve

[0040] 330: Driven gear

[0041] 331: First tooth

[0042] 332: Second tooth

[0043] 340: Elastic element

[0044] 400: Adjustable Gap Module

[0045] 411, 412: Cam

[0046] 421, 422: Microswitches

[0047] 430: Drive wheel

[0048] 440: Potentiometer

[0049] 500: Main screw

[0050] 510: Head

[0051] 520: Main Screw Section

[0052] 600: Worm Gear Bearing

[0053] 700: Outer casing

[0054] 710: First Shell

[0055] 720: Second shell

[0056] 730: Tail Cover

[0057] 740: Threading groove

[0058] 750: Card slot

[0059] 800: Stabilizing bushing

[0060] 810: First Ring Wall

[0061] 820: Second Ring Wall Detailed Implementation

[0062] Embodiments of this disclosure will now be described with reference to the accompanying drawings. For clarity, numerous practical details will be set forth in the following description. However, the reader should understand that these practical details should not be used to limit this disclosure. That is, in some embodiments of this disclosure, these practical details are not essential. Furthermore, for the sake of simplicity in the drawings, some conventionally used structures and elements will be illustrated in a simple schematic manner; and repeated elements may be denoted by the same or similar designations.

[0063] Furthermore, the terms "first," "second," and "third" used in this document are merely used to describe different components or elements, and do not impose any restrictions on the components / components themselves. Therefore, the first component / component can also be referred to as the second component / component. Moreover, the combinations of components / components / mechanisms / modules in this document are not combinations generally known, conventional, or existing in this field. Whether the components / components / mechanisms / modules themselves are existing cannot be used to determine whether their combination relationships are easily accomplished by those skilled in the art.

[0064] Figure 1 A perspective schematic diagram of a linear actuator 10 according to an embodiment of the present disclosure is shown. Figure 2 Draw Figure 1 A partial exploded view of the linear actuator 10 in the embodiment. Figure 3 Draw Figure 1 A partial top view of the linear actuator 10 of the embodiment. The linear actuator 10 includes a drive mechanism 100, a main worm gear 200, a main screw 500, a reduction mechanism 300, and a pitch adjustment module 400. The drive mechanism 100 includes a worm shaft 110. The main worm gear 200 meshes with the worm shaft 110. The main screw 500 is coaxially arranged with the main worm gear 200 and rotates in conjunction with it. The reduction mechanism 300 includes a reduction worm gear 310, a bevel gear 320, and a driven gear 330. The reduction worm gear 310 is coaxially arranged with the main worm gear 200 and rotates in conjunction with it. The reduction worm gear 310 includes an external thread 311. The bevel gear 320 is sleeved on the outside of the worm shaft 110 and does not rotate in conjunction with the worm shaft 110. The bevel gear 320 meshes with the reduction worm gear 310. Driven gear 330 is orthogonal to and meshes with bevel gear 320. Adjustment module 400 includes a cam 411, 412 and a microswitch 421, 422 (illustrated in...). Figure 4 Cams 411 and 412 are driven to rotate by driven gear 330. Microswitches 421 and 422 correspond to cams 411 and 412. Among them, the worm shaft 110 drives the main worm wheel 200, which in turn drives the reduction worm wheel 310 and the main screw 500 to rotate. This causes the reduction worm wheel 310 to drive the bevel gear 320, which in turn drives the driven gear 330. Cams 411 and 412 trigger microswitches 421 and 422.

[0065] By making the reduction worm gear 310 coaxial with the main worm gear 200 and the bevel gear 320 fitted onto the worm shaft 110, the number of gears can be reduced, and spatial configuration can be improved, thus reducing the size of the linear actuator 10.

[0066] Please see Figure 4 See also Figures 1 to 3 ,in Figure 4 Draw Figure 1A partial cross-sectional schematic diagram of the linear actuator 10 in the embodiment. The linear actuator 10 may further include a housing 700, which may include a first housing 710, a second housing 720 and a tail cover 730. The first housing 710 and the second housing 720 are assembled to form an accommodating space for accommodating the worm shaft 110, the main worm gear 200, the reduction mechanism 300 and the pitch adjustment module 400 therein. The tail cover 730 is integrally connected to the first housing 710. The first housing 710 and the tail cap 730 can be integrally manufactured, or connected by welding or fusion. The outer shell 700 may also include a round tube (not shown), an opening (not shown), and a slot 750. The round tube is connected to a back side of the first housing 710 and communicates with the internal space. Both the first housing 710 and the second housing 720 include a semi-circular hole and a semi-circular slot. The semi-circular slot is adjacent to the semi-circular hole. Therefore, after the first housing 710 and the second housing 720 are assembled, the two semi-circular holes can form an opening to allow the main screw 500 to extend, and the two semi-circular slots can form a slot 750 located at the upper end of the opening.

[0067] In this embodiment, the outer casing 700 may further include a wire-passing groove 740, which is formed in the second casing 720 to allow a wire to pass through and be restrained. Specifically, the wire-passing groove 740 may be formed on one front side of the second casing 720 and communicate with the internal space. Therefore, wires such as electrical wires in the internal space can pass through the wire-passing groove 740 and be restrained by the wire-passing groove 740 to improve ease of use. In other embodiments, the wire-passing groove may not be provided, and this is not a limitation.

[0068] The drive mechanism 100 can be used to drive the main screw 500 to rotate. It may also include a motor stator 120 and a motor rotor 130. The motor stator 120 can be connected to the circular tube and includes a coil for current to pass through. The motor rotor 130 is inserted into the motor stator 120 to rotate under the action of a magnetic field. The worm shaft 110 can be connected to the motor rotor 130 to be driven by the motor rotor 130, and the worm shaft 110 extends from the inside of the circular tube into the internal space.

[0069] The worm shaft 110 may include a threaded section 111 and a connecting section 112 connected to each other. The threaded section 111 engages with the main worm gear 200, and the connecting section 112 is on which the bevel gear 320 is fitted. Specifically, the worm shaft 110 is rod-shaped, and after passing through the motor rotor 130, a portion of it will be exposed outside the motor rotor 130. Depending on whether it has threads, it can be divided into a threaded section 111 and a connecting section 112. The connecting section 112 may be adjacent to the motor rotor 130 and includes a smooth surface.

[0070] The main worm gear 200 may include a wheel body 210 and a fitting tube 220 coaxially connected. The wheel body 210 meshes with the worm spindle 110, and the fitting tube 220 fits into the reduction worm gear 310. Specifically, the wheel body 210 includes external teeth to correspond to the threaded section 111 of the worm spindle 110 and can be driven by the threaded section 111. The main worm gear 200 may also include an inner hole (not shown) and a connecting shaft 230. The inner hole is located in the upper half of the wheel body 210 and communicates with the interior of the fitting tube 220. The connecting shaft 230 can fit into the inner hole to rotate in conjunction with the wheel body 210. The fitting tube 220 may integrally protrude from the lower half of the wheel body 210, that is, the fitting tube 220 is connected to the side of the wheel body 210 away from the tail cover 730. The fitting tube 220 may include multiple first concave and convex portions to cooperate with the reduction worm gear 310. The linear actuator 10 may further include a worm gear bearing 600, which may be sleeved on the end of the connecting shaft 230 away from the wheel body 210.

[0071] The main screw 500 may include a head 510 and a main screw portion 520. The head 510 can pass through the main worm gear 200 and the worm gear bearing 600, and is riveted to prevent the main screw 500 from disengaging from the worm gear bearing 600. The main screw portion 520 is connected to the head 510 and is partially cut off to form a limiting section, so that it can mate with the square hole of the connecting shaft 230.

[0072] The linear actuator 10 may further include a stabilizing sleeve 800, which is fitted onto the main screw 500 and located within a slot 750. Specifically, the stabilizing sleeve 800 may be a dummy bearing, comprising a first annular wall 810 and a second annular wall 820 coaxially connected. The first annular wall 810 is fitted into the slot 750, and the second annular wall 820 extends into the opening. Thus, the configuration of the stabilizing sleeve 800 prevents the main screw 500 from wobbling.

[0073] The reduction worm gear 310 can be disposed below the main worm gear 200 and includes an annular body 312. The annular body 312 tapers towards the gear body 210 into a conical shape and includes an outer conical surface (not shown). An external thread 311 is disposed on the outer conical surface. Specifically, the reduction worm gear 310 may include a connecting hole (not shown) penetrating the annular body 312 to form an inner bore surface. A plurality of second protrusions and concave portions can be disposed on the inner bore surface. Therefore, when the fitting tube 220 is inserted into the connecting hole, the first protrusions and concave portions engage with the second protrusions and concave portions, enabling the reduction worm gear 310 to rotate in conjunction with the main worm gear 200. By disposing the reduction worm gear 310 below the main worm gear 200 and having an outer conical surface, it is possible to further reduce the size of the linear actuator 10.

[0074] like Figure 2 and Figure 3As shown, the bevel gear 320 can be located on the right side of the reduction worm gear 310. The bevel gear 320 includes a plurality of grooves 321, which are arranged around an inclined surface of the bevel gear 320. The external thread 311 protrudes into one of the grooves 321, thereby enabling the bevel gear 320 to mesh with the reduction worm gear 310. The bevel gear 320 includes an inner sleeve 323 and a bevel top 322. The inner sleeve 323 is fitted onto the connecting section 112. The bevel top 322 is connected to one end of the inner sleeve 323 and covers the inner sleeve 323. The bevel top 322 includes a top surface (not shown), an inclined surface (not shown), and an outer annular surface (not shown). The inclined surface is connected between the top surface and the outer annular surface. The groove 321 is recessed in the inclined surface and partially extends to the outer annular surface and the top surface. An extension line of the groove 321 forms an angle with a radial direction of the worm shaft 110.

[0075] The reduction mechanism 300 may further include an elastic element 340, which may be sleeved on the connecting section 112 and located further away from the threaded section 111 than the bevel gear 320. The elastic element 340 may be a disc washer, a wave washer, or a spring sheet, and may push the bevel gear 320 toward the reduction worm gear 310 to reduce the tooth backlash between the reduction worm gear 310 and the bevel gear 320, but is not limited thereto.

[0076] The driven gear 330 may include a first tooth portion 331 and a second tooth portion 332. The first tooth portion 331 can mesh with the bevel gear 320, and the second tooth portion 332 is axially connected to the first tooth portion 331. Therefore, when the first tooth portion 331 is driven to rotate by the bevel gear 320, the second tooth portion 332 can also rotate.

[0077] The pitch adjustment module 400 may further include a drive wheel 430, which meshes with the second tooth 332 and is linked to the cams 411 and 412. Specifically, there are two cams 411 and 412, and there are also two microswitches 421 and 422. The two cams 411 and 412 are coaxial and side by side with the drive wheel 430, and each cam 411 and 412 includes a protrusion for pressing against the spring of the microswitches 421 and 422 respectively.

[0078] Therefore, the drive wheel 430 can be driven by the second tooth 332, and together drive the two cams 411 and 412 to rotate. The micro switch 421 or micro switch 422 is triggered by the protrusion, and the drive mechanism 100 is automatically stopped at the longest or shortest stroke. The pitch adjustment module 400 may also include a potentiometer 440 coaxially arranged with the two cams 411 and 412. The potentiometer 440 may be a variable resistor, and its resistance value can be changed by rotation. The position of the main screw 500 can be detected by the resistance change, and the drive mechanism 100 can also be stopped at a preset position.

[0079] Although this disclosure has been presented above with reference to embodiments, it is not intended to limit this disclosure. Any person skilled in the art can make various changes and modifications without departing from the concept and scope of this disclosure. Therefore, the scope of protection of this disclosure shall be determined by the claims.

Claims

1. A linear actuator, characterized in that, Include: A drive mechanism, comprising a worm gear spindle; A main worm gear meshes with the worm spindle; A main screw is coaxially mounted with the main worm gear and rotates in conjunction with it. A speed reduction mechanism, comprising: A reduction worm gear is coaxially disposed below the main worm gear and rotates in conjunction with the main worm gear; the reduction worm gear includes an external thread. A bevel gear, sleeved on the outside of the worm shaft but not rotating with it, includes multiple grooves arranged around an inclined surface of the bevel gear. The bevel gear meshes with the reduction worm gear, such that the external thread protrudes into one of the multiple grooves. A driven gear, orthogonal to and meshing with the bevel gear; and A distance adjustment module, comprising: A cam, driven to rotate by the driven gear; and A micro switch corresponds to the cam; The worm shaft drives the main worm wheel, which in turn drives the reduction worm wheel and the main screw to rotate. This causes the reduction worm wheel to drive the bevel gear, which in turn drives the driven gear. The cam triggers the micro switch.

2. The linear actuator as claimed in claim 1, characterized in that, The worm shaft includes a threaded section and a connecting section that are connected to each other. The threaded section engages with the main worm wheel, and the connecting section is for the bevel gear to be fitted onto it.

3. The linear actuator as described in claim 2, characterized in that, The main worm gear includes a wheel body and a fitting tube coaxially connected. The wheel body meshes with the worm spindle, and the fitting tube fits into the reduction worm gear.

4. The linear actuator as described in claim 3, characterized in that, It also includes an outer casing, which includes a first housing, a second housing, and a tail cover. The first housing and the second housing are assembled to form an accommodating space for accommodating the worm shaft, the main worm wheel, the reduction mechanism, and the pitch adjustment module therein. The tail cover is integrally connected to the first housing, and the fitting tube is connected to the side of the wheel body away from the tail cover.

5. The linear actuator as claimed in claim 4, characterized in that, The housing also includes a threading groove formed in the second housing to allow a wire to pass through a limiting position.

6. The linear actuator as claimed in claim 3, characterized in that, The reduction worm gear includes an annular body that tapers towards the gear body into a cone shape and includes an outer conical surface, on which an external thread is disposed.

7. The linear actuator as claimed in claim 2, characterized in that, The deceleration mechanism also includes an elastic element that is fitted onto the connecting section and is located further away from the threaded section than the bevel gear.

8. A linear actuator, characterized in that, Include: A shell; A drive mechanism, comprising a worm gear spindle housed within the housing; A main worm gear meshes with the worm spindle; A main screw is coaxially arranged with and rotates in conjunction with the main worm gear, and the main screw protrudes from the housing; A speed reduction mechanism, comprising: A reduction worm gear is coaxially arranged with and rotates in conjunction with the main worm gear, and the reduction worm gear includes an external thread; A bevel gear, fitted onto the outside of the worm shaft but not rotating with it, meshes with the reduction worm wheel; and A driven gear, orthogonal to and meshing with the bevel gear; and A distance adjustment module, comprising: A cam, driven to rotate by the driven gear; and A micro switch corresponds to the cam; The worm shaft drives the main worm wheel, which in turn drives the reduction worm wheel and the main screw to rotate. This causes the reduction worm wheel to drive the bevel gear, which in turn drives the driven gear. The cam triggers the micro switch.

9. The linear actuator as claimed in claim 8, characterized in that, The main worm gear includes a wheel body and a fitting tube coaxially connected. The wheel body meshes with the worm spindle, and the fitting tube is fitted into the reduction worm gear. The reduction worm gear includes an annular body that tapers towards the wheel body into a cone shape and includes an outer conical surface. The external thread is provided on the outer conical surface.

10. The linear actuator as claimed in claim 9, characterized in that, It also includes a stabilizing bushing, the housing having an opening and a slot, the opening for the main screw to extend outward, the slot communicating with the opening, and the stabilizing bushing being fitted onto the main screw and located in the slot.

Images