TWI421421B - High-load linear actuator - Google Patents

Description

High load linear actuator

The present invention relates to an actuator, and more particularly to a high load linear actuator for use in medical equipment, electric chairs, and the like.

With the development of the economy and the affluence of the society, the Chinese people ingest a large amount of high-nutrition and high-calorie ingredients in the diet, so that the average weight of the Chinese people is continuously increased; under the influence of the above reasons, they are engaged in medical equipment or electric chairs. Manufacturers must innovate and improve the Linear Actuator, which is widely used in the aforementioned equipment, to continue to manufacture or design products that meet market needs.

In the past, linear actuators mainly used a motor with a worm and a worm gear to drive the lead screw to rotate, and at the same time, the lead screw drives the telescopic tube screwed thereon to linearly extend or retract; A linear actuator is assembled.

Since the traditional linear actuator configuration can only be used on lower-load medical devices, the high-load linear actuators required by the market cannot meet the linear actuator due to safety load considerations and service life problems. Stage product requirements. In addition, the linear actuator used in high-load equipment, the speed of the telescopic tube during the retracting process, also affects the comfort and safety of the user. And so on, they are all to be improved to overcome.

It is an object of the present invention to provide a high load linear actuator which can be applied to a high load apparatus by means of a configuration of a drive mechanism and a worm gear assembly to form a stable support.

In order to achieve the above object, the present invention provides a high load linear actuator comprising a driving mechanism, a worm, a worm gear assembly, a lead screw, a telescopic tube and an outer tube, the driving mechanism comprising a base and An electric motor capable of generating a positive and negative reversal, the base having a receiving portion and a seating portion, the receiving portion comprising a body and a hollow cylinder extending from the seat body, the mounting portion comprising the hollow tubular column a ring body, the motor is fixed to the seat body; the worm is protruded from the motor and penetrates into the hollow cylinder; the worm gear assembly includes a worm wheel and a common worm wheel supporting the inside of the ring body a bearing, the worm gear is meshed with the worm; the lead screw penetrates the worm wheel and is rotated by the actuation of the motor; the telescopic tube is sleeved outside the lead screw and screwed to the lead screw; The outer tube is sleeved outside the telescopic tube, and the telescopic tube is driven by the rotation of the lead screw to generate linear telescopic movement relative to the outer tube.

The invention also has the following effects. By the combined design of the base and the worm gear assembly, not only the stability of the worm wheel supported in the ring body can be improved, but also the assembly and maintenance process is simplified and the disassembly and assembly time is shortened. By the arrangement of the reduction transmission mechanism, the friction between the respective needles and the intermediate ring is utilized, so that the rotation of the lead screw in a specific direction is hindered, and the deceleration effect can be achieved. The intermediate ring can be easily rotated inside the torsion spring to make the transmission performance of the transmission mechanism good. Guide screw When the rod is pushed back by force, the intermediate ring, each needle roller, the passive bushing and the lead screw can not be driven relative to each other, so that the lead screw is firmly fixed, and the lead screw and the nut can be effectively prevented. Self-slip occurs. The friction between the transmission elements increases as the load increases, so no unnecessary friction is generated during no-load without consuming energy, and the retraction speed of the telescopic tube is approximately the same under different loads, thus maintaining Decrease in the case of constant speed, and improve user comfort.

10‧‧‧ drive mechanism

11‧‧‧After

111‧‧‧Receiving Department

112‧‧‧ body

113‧‧‧ hollow cylinder

115‧‧‧Relocation Department

116‧‧‧Circular ring

1161‧‧‧post steps

117‧‧‧ cover

1171‧‧ ‧ front steps

12‧‧‧Electric motor

20‧‧‧ worm

30‧‧‧worm gear assembly

31‧‧‧ worm gear

311‧‧‧Ring tooth surface

312‧‧‧ hollow shaft

313‧‧‧ 前容槽

314‧‧‧ Hourong

315‧‧‧ internal teeth

32‧‧‧ front bearing

33‧‧‧ rear bearing

40‧‧‧ lead screw

41‧‧‧ thread segments

42‧‧‧round shaft

421‧‧‧Outer positioning plane

50‧‧‧ telescopic tube

51‧‧‧ tube body

52‧‧‧ nuts

521‧‧‧Block

60‧‧‧External management

61‧‧‧ trench

65‧‧‧ rear support mechanism

651‧‧‧ half cover

652‧‧‧Ball bearings

653‧‧‧Slot

70‧‧‧Reducing gear mechanism

71‧‧‧ driven wheel

711‧‧‧ external teeth

72‧‧‧ claw ring

721‧‧‧ card slot

722‧‧‧ claw arm

723‧‧‧ spacing slot

73‧‧‧Passive bushings

731‧‧‧ inner plane

732‧‧ ‧ ribs

733‧‧‧ Groove

74‧‧‧needle needle

75‧‧‧Intermediate ring

76‧‧‧Torque spring

761‧‧‧ positioning segment

77‧‧‧Limited door

80‧‧‧ Shell

90‧‧‧Electrical unit

The first figure is an appearance view of the linear actuator combination of the present invention.

The second drawing is an exploded perspective view of the drive mechanism and the worm gear assembly of the present invention.

The third figure is another perspective view of the second figure.

The fourth drawing is a sectional view of each component combination of the second drawing.

The fifth figure is an exploded perspective view of the linear actuator of the present invention.

Figure 6 is a perspective exploded view of the reduction transmission mechanism of the present invention.

Figure 7 is a cross-sectional view showing the combination of the reduction transmission mechanism of the present invention.

The eighth figure is a schematic diagram of the combination of the linear actuators of the present invention.

Figure 9 is a cross-sectional view of the linear actuator assembly of the present invention.

The detailed description and technical content of the present invention are set forth in the accompanying drawings.

Referring to the first figure, the present invention provides a high load linear actuator which is mainly applied to loads of several hundred kilograms or more, including a driving mechanism 10, a worm 20, and a worm gear assembly 30. A lead screw 40, a telescopic tube 50 (as shown in the eighth figure) and an outer tube 60.

Referring to the second to fourth figures, the driving mechanism 10 includes a base 11 and a motor 12 capable of generating a forward and reverse rotation. The base 11 has a receiving portion 111 and a seating portion 115. The receiving portion 111 is formed by a plate. The base body 112 is formed by a hollow cylinder 113 formed by extending upwardly from the base body 112. The motor 12 is locked under the seat body 112 by screws (not shown). The seating portion 115 includes a circular ring body 116 and a cover plate 117. The circular ring body 116 is integrally formed with the seat body 112 and the hollow cylinder column 113. Further, a rear step 1161 is formed on the inner side of the circular ring body 116; the cover plate 117 is locked to one side of the circular ring body 116 by a screw (not shown), and the cover plate 117 is corresponding to the circular ring body. A front step 1171 is also formed on one side of the 116 (as shown in the third figure).

The worm 20 may protrude from the center of the motor 12 in the axial center of the motor 12, or may extend from the center of the motor 12 in a connected manner. When the motor 12 is fixed to the seat 112, the worm 20 is penetrated into the hollow. The inside of the column 113, and the free end thereof is received by the sleeve and placed in the hollow cylinder column 113, thereby increasing the stability of the holding.

The worm gear assembly 30 includes a worm wheel 31, a front bearing 32 and a rear bearing 33. The worm wheel 31 has an annular tooth surface 311 and a hollow hollow shaft 312 connecting the annular tooth surface 311, and the annular tooth surface 311 and the hollow hollow shaft 312. Forming front and rear pockets 313, 314, and forming an internal gear 315 on the rear side of the hollow shaft 312 (such as the third As shown, the annular tooth surface 311 is in meshing engagement with the aforementioned worm 20. Referring to the fourth figure, the front bearing 32 is sleeved in the middle hollow shaft 312 and accommodated in the front pocket 313. A portion of the outer circumference of the front bearing 32 is exposed outside the annular tooth surface 311, and the bearing 32 is bare before. The area is fixed in the front step 1171 of the cover plate 117; similarly, the rear bearing 33 is also sleeved in the middle hollow shaft 312 and accommodated in the rear pocket 314, and a part of the outer circumference of the rear bearing 33 is exposed. The outer portion of the annular tooth surface 311 is formed; thereafter, the exposed portion of the bearing 33 is fixed in the rear step 1161 of the circular ring body 116; thus, the circular ring body 116 and the cover plate for supporting the worm wheel 31 in the seating portion 115 in common 117.

Referring to the fifth figure, the lead screw 40 has a threaded section 41 and a circular shaft section 42 extending from the threaded section 41. An outer positioning plane 421 is disposed at an end of the circular shaft section 42 away from the threaded section 41. One end of the screw 40 is inserted into the hollow shaft 312 of the worm wheel 31 (as shown in the ninth figure), and the other end extends outwardly away from the frame 11. The lead screw 40 drives the worm with the motor 12. 20 and drive the worm wheel 31 to generate a rotating motion.

The telescopic tube 50 has a tube body 51 and a nut 52 fixed to the end of the tube body 51. The nut 52 is screwed to the lead screw 40 (as shown in FIG. 9), and the nut 52 is A plurality of inserts 521 are protruded from the outer periphery.

The outer tube 60 is sleeved on the outside of the tube 51 of the telescopic tube 50 (as shown in the first figure), and a plurality of grooves 61 (shown in FIG. 9) for inserting the above-mentioned inserts 521 are disposed inside the outer tube 60. By restricting the rotation of the telescopic tube 50, the telescopic tube 50 is linearly telescopically moved relative to the outer tube 60 after being driven by the rotation of the lead screw 40.

The linear actuator of the present invention further includes a rear support mechanism 65 (as shown in FIG. 5), which mainly includes two half covers 651 and a ball bearing 652 which is clamped and fixed by the two half covers 651. The bearing 652 is disposed for the end of the lead screw 40 to be pierced; thus, the actuation stability of the lead screw 40 and the telescopic tube 50 can be further improved. Another slot 653 is formed at the junction of the second half cover 651.

Referring to Figures 6 and 7, the linear actuator of the present invention further includes a reduction transmission mechanism 70 that is sleeved between the lead screw 40 and interposed between the rear support mechanism 65 and the worm gear assembly 30. The transmission mechanism 70 mainly includes a driven wheel 71, a claw ring 72, a passive bushing 73, a plurality of needle rollers 74, an intermediate ring 75, a torsion spring 76 and a limit stop cover 77; the driven wheel 71 is sleeved at The cylindrical shaft portion 42 of the lead screw 40 is located, and has a plurality of external teeth 711 which are partially connected to the internal teeth 315 of the worm wheel 31. The claw ring 72 is provided with a plurality of card slots 721 which are mutually engaged with the external teeth 711. The claw ring 72 is formed with a plurality of claw arms 722, and a spacing groove 723 is formed between any two adjacent claw arms 722.

The passive bushing 73 is provided with an inner positioning plane 731, and a plurality of ribs 732 extend from the outer periphery of the passive bushing 73. A recess 733 is formed between any two adjacent ribs 732, and the passive bushing 73 is sleeved at The lead screw 40 is rotated by the inner positioning plane 731 and the outer positioning plane 421 of the circular shaft section 42, and the passive sleeve 73 is received in each claw arm 722 of the claw ring 72; The needles 74 are respectively inserted into the spaces formed by the respective spacing grooves 723 and the respective grooves 733; the intermediate ring 75 is sleeved on the outer circumference of the claw ring 72 and is in contact with the respective needle rollers 74. The torsion spring 76 is bent with a positioning section 761. The torsion spring 76 elastically tightens the outer circumference of the intermediate ring 75, and the positioning section 761 penetrates into the slot 653 to be solid. set. The limit stop cover 77 is sleeved on one side of the passive bushing 73 and seals the claw ring 72 and the end faces of the respective needle rollers 74 (as shown in the ninth figure).

Referring to FIGS. 8 and 9, the linear actuator of the present invention further includes a housing 80 which is wrapped around the drive mechanism 10 and the reduction transmission mechanism 70 and supported by the rear support mechanism 65 and provided for the outer tube. One side of the 60 is placed and placed.

Further, the linear actuator of the present invention further includes an electric unit 90 (shown in the first figure) which is disposed inside the outer casing 80 and located at one side of the motor 12.

Referring to the eighth figure, when the worm wheel 31 is rotated in the clockwise direction by the worm gear 20 in the forward direction, that is, the lead screw 40 of the lead screw 40 is retracted into the outer tube 60; Each of the claw arms 722 will push the intermediate ring 75 and the respective needle rollers 74 to rotate. The direction of rotation of the torsion spring 76 is the same as the direction of rotation of the worm wheel 31, and the positioning portion 761 is fixed in the slot 653 of the half cover 651 (eg, The five-figure spring 76 causes the torsion spring 76 to produce a tightening of the intermediate ring 75 (ie, the intermediate ring 75 is tightly held and cannot rotate), so that each of the claw arms 722 drives the respective needle 74 and the intermediate ring. The frictional force of 75 is increased, and the rotation speed of the lead screw 40 is lowered; thus, when the linear actuator is mounted on the electric bed or the chair, the speed of the telescopic tube 50 retracting into the outer tube 60 is slower to increase the user's Use comfort.

When the worm wheel 31 is driven by the worm gear 20 to rotate in the counterclockwise direction, that is, the lead screw 40 drives the extension tube 50 to extend outwardly from the outside of the outer tube 60; Continuing to refer to the seventh figure, each of the claw arms 722 will push the intermediate ring. 75 and each of the needle rollers 74 rotates, since the direction of rotation of the torsion spring 76 is opposite to the direction of rotation of the worm wheel 31, the torsion spring 76 will be The rotation of the intermediate ring 75 causes a loose state. At this time, the frictional damping between the intermediate ring 75, the torsion spring 76 and each of the needle rollers 74 is small, so that the intermediate ring 75 can be easily rotated inside the torsion spring 76; The transmission of the internal mechanism is good.

In summary, the high-load linear actuator of the present invention can achieve the intended use purpose, and solves the lack of the prior art, and is extremely novel and progressive, fully conforms to the requirements of the invention patent application, and is proposed according to the patent law. To apply, please check and grant the patent in this case to protect the rights of the inventor.

10‧‧‧ drive mechanism

11‧‧‧After

111‧‧‧Receiving Department

112‧‧‧ body

113‧‧‧ hollow cylinder

115‧‧‧Relocation Department

116‧‧‧Circular ring

1161‧‧‧post steps

117‧‧‧ cover

12‧‧‧Electric motor

20‧‧‧ worm

30‧‧‧worm gear assembly

31‧‧‧ worm gear

311‧‧‧Ring tooth surface

312‧‧‧ hollow shaft

313‧‧‧ 前容槽

32‧‧‧ front bearing

33‧‧‧ rear bearing

Claims (11)

A high load linear actuator comprising: a driving mechanism comprising a base and an electric motor capable of generating a positive and negative reversal, the base having a receiving portion and a seating portion, the receiving portion comprising a body and the seat a hollow tubular column formed by the body extension, the seating portion comprising a ring body connected to the hollow cylinder column, the motor is fixed to the seat body; a worm protruding from the motor and penetrating into the hollow cylinder column; a worm gear assembly comprising a worm wheel and two bearings supporting the worm wheel inside the ring body, the worm gear system meshing with the worm gear; a lead screw passing through the worm wheel and being rotated by the actuation of the motor a telescopic tube sleeved outside the lead screw and screwed to the lead screw; and an outer tube sleeved outside the telescopic tube, the telescopic tube being driven by the rotation of the lead screw and generated relative to the outer tube a linear telescopic movement; wherein the worm wheel has an annular tooth surface that meshes with the worm and a hollow hollow shaft that connects the annular tooth surface, and a front pocket is formed between the annular tooth surface and the radial direction of the hollow shaft After receiving slot, the two ends of the bearing sockets in the hollow shaft and are accommodated in the front groove and the receiving groove after capacity, and the ring gear bearing surface covers the outer peripheral edge of the two partial regions. The high load linear actuator of claim 1, wherein the seating portion further comprises a cover plate fixed to a side of the ring body, the ring body and the hollow cylinder column being integrally formed. The high-load linear actuator of claim 2, wherein another portion of the outer circumference of the two bearings respectively exposes an outer portion of the annular tooth surface, and a rear step is formed on an inner side of the ring body, the cover plate corresponding thereto One side of the ring body is formed with a front step, and the exposed portions of the two bearings are supported by the front step and the rear step, respectively. The high load linear actuator of claim 1, further comprising a rear support mechanism comprising two half covers and a ball bearing fixedly clamped by the two half covers, the ball bearing The lead screw is placed for connection. The high load linear actuator of claim 4, further comprising a reduction transmission mechanism sleeved between the lead screw and between the rear support mechanism and the worm gear assembly. The high load linear actuator of claim 1, further comprising a reduction transmission mechanism comprising a driven wheel, a claw ring, a passive bushing, a plurality of needle rollers, an intermediate ring and a torque a spring, the driven wheel sleeves the lead screw and penetrates the worm wheel, the claw ring sleeves the driven wheel to synchronously interlock with the worm wheel and the driven wheel, the passive sleeve sleeves the lead screw and is connected to the claw ring The needle rollers are threaded between the passive bushing and the intermediate ring, and the torsion spring elastically tightens the outer circumference of the intermediate ring. The high load linear actuator of claim 6, wherein the worm wheel is provided with a plurality of internal teeth, and the driven wheel is formed with a plurality of external teeth that are engaged with the internal teeth, and the claw ring is also provided with A plurality of card slots that are externally clamped to each other. The high-load linear actuator of claim 6, wherein the claw ring is formed with a plurality of claw arms, and a spacing groove is formed between any two adjacent claw arms, and the outer circumference of the passive sleeve extends with a plurality of ribs. Forming a gap between any two adjacent ribs a groove, the needle is received in the space defined by the spacing groove and the groove, and the needle rollers are surrounded by the intermediate ring. The high load linear actuator of claim 6, wherein the lead screw has an outer positioning plane, and the passive sleeve is provided with an inner positioning plane that is mutually engaged with the outer positioning plane. The high-load linear actuator of claim 6, further comprising a casing that is wrapped around the driving mechanism and the reduction transmission mechanism and is placed for one side of the outer tube. The high load linear actuator of claim 10, further comprising an electrical unit disposed inside the outer casing and on one side of the electric motor.