CN107035836A - linear actuator - Google Patents

Abstract

The present invention provides a linear actuator, which has a relatively simple structure and is easy to ensure assembly accuracy. The linear actuator of the present invention includes: a driving part having a rotatable output shaft; a linear motion mechanism driven by the driving part; and a housing for accommodating the linear motion mechanism, wherein the driving part has a lead screw coaxially fixed to the output shaft, and the linear motion mechanism includes: a nut, which is screwed with the lead screw in a manner that can move along the axial direction of the output shaft; and a protrusion, which is provided on the nut in a manner that protrudes from the axial side of the output shaft toward the radial outer side of the output shaft, and the housing has an opening extending along the axial direction of the output shaft, and the protrusion is accommodated in the opening.

Description

linear actuator

technical field

The present invention relates to a linear actuator, in particular to a linear actuator capable of converting rotary motion into linear motion for output.

Background technique

A linear actuator that converts rotary motion into linear motion for output has been widely used in industrial fields. In order to convert rotary motion into linear motion, this kind of linear actuator usually uses multiple conversion components such as screw, nut, guide sleeve and push rod, and the structure is relatively complicated. In addition, linear actuators are often used to precisely control the motion stroke, so it is necessary to ensure the assembly accuracy of its constituent parts.

Contents of the invention

The present invention is made to solve the above problems, and the purpose of the present invention is to provide a linear actuator, which has a relatively simple structure and is easy to ensure assembly accuracy.

In order to achieve the above object, the linear actuator of the first aspect of the present invention includes: a driving part having a rotatable output shaft; a linear motion mechanism driven by the driving part; and a housing for accommodating the linear motion mechanism, wherein , the driving part has a lead screw coaxially fixed to the output shaft, and the linear motion mechanism includes: a nut that is movable along the axial direction of the output shaft with the lead screw. and a protrusion provided on the nut so as to protrude from the axial center side of the output shaft toward the radially outer side of the output shaft, and the housing has a an opening extending in the axial direction, and the protruding portion is accommodated in the opening.

According to the linear actuator of the first aspect of the present invention, it is only necessary to provide a protruding part on the nut screwed with the screw of the driving part, and to provide an opening for accommodating the protruding part on the housing, so that the output of the driving part can be formed. The conversion structure converts rotary motion into linear motion, so the structure is simple. In addition, when assembling the linear actuator, since the protrusion provided on the nut can be guided by the opening of the case, it can be assembled with high precision.

A linear actuator according to a second aspect of the present invention is the linear actuator according to the first aspect of the present invention, wherein the housing has: a first storage portion that houses the drive unit; and a second storage portion part, the second storage part stores the nut, and the second storage part has the opening part.

In the linear actuator of the third aspect of the present invention, in the linear actuator of the first aspect of the present invention, the distance from the axis of the output shaft to the front end of the protrusion is greater than the distance from the axis of the output shaft to The maximum distance of the inner surface of the portion of the case housing the linear motion mechanism is long.

According to the linear actuator according to the third aspect of the present invention, when the linear motion mechanism is accommodated in the case, if the assembly position of the linear motion mechanism is incorrect, the protruding portion will interfere with the case, so that wrong assembly can be avoided.

The linear actuator according to the fourth aspect of the present invention is the linear actuator according to any one of the first aspect to the third aspect of the present invention, wherein a plurality of the protrusions are provided, and the opening and the protrusions Correspondingly, there are a plurality of them.

In the linear actuator of the fifth aspect of the present invention, in the linear actuator of the fourth aspect of the present invention, two of the protrusions are provided at angular intervals of 180 degrees in the circumferential direction around the axis of the output shaft, A distance between the front ends of the two protrusions is longer than a maximum inner diameter of a portion of the case housing the linear motion mechanism.

According to the linear actuator of the fifth aspect of the present invention, by providing two protrusions at an angular interval of 180 degrees in the circumferential direction around the axis of the output shaft, when the linear actuator is driven, the nut can be rotated around the output shaft. The force balance in the circumferential direction of the axis helps to improve the output precision of the linear actuator. In addition, when the linear motion mechanism is housed in the case, if the assembly position of the linear motion mechanism is incorrect, the protruding portion will interfere with the case, and therefore, erroneous assembly can be avoided.

The linear actuator according to the sixth aspect of the present invention is the linear actuator according to any one of the first aspect to the fifth aspect of the present invention, wherein the housing is divided into a first housing and a second housing along the axial direction. The housing, the opening is formed on the butt surface of the first housing and the second housing.

According to the linear actuator of the sixth aspect of the present invention, when the linear motion mechanism is mounted on the housing, after the nut is assembled in one of the first housing and the second housing, the other can be covered. Therefore, it is not difficult to assemble the linear motion mechanism to the housing due to the protruding part provided on the nut, which helps to improve the assembly efficiency.

The linear actuator according to the seventh aspect of the present invention is the linear actuator according to any one of the first to fifth aspects of the present invention, wherein the protruding portion is provided with a Anti-snag protrusions.

According to the linear actuator according to the seventh aspect of the present invention, the contact area between the protrusion and the housing can be reduced, which helps to prevent the protrusion from biting due to repeated collisions with the edge of the opening of the housing, and helps to improve linearity. The working stability of the actuator.

The linear actuator according to the eighth aspect of the present invention is the linear actuator according to any one of the first to fifth aspects of the present invention, wherein the protruding part is arranged on the side of the nut close to the driving part .

According to the linear actuator of the eighth aspect of the present invention, compared with the case where the protruding portion is provided on the side of the nut away from the driving portion, it contributes to downsizing of the linear actuator.

A linear actuator according to a ninth aspect of the present invention is the linear actuator according to any one of the first to fifth aspects of the present invention, wherein the drive section includes a motor having the output shaft.

Invention effect

According to the linear actuator of the present invention, it is only necessary to provide a protruding part on the nut screwed with the lead screw of the driving part, and to provide an opening for accommodating the protruding part on the housing, so that the rotational motion output from the driving part can be converted The conversion structure moves in a straight line, therefore, the structure is simple. In addition, when assembling the linear actuator, since the protruding portion of the nut can be guided by the opening of the case, assembly can be performed with high precision.

Description of drawings

FIG. 1 is a perspective view showing a linear actuator according to an embodiment of the present invention, and shows a state where a nut is in a retracted position.

FIG. 2 is a diagram showing the internal structure of the linear actuator according to the embodiment of the present invention, and shows a state where the second housing 30B is removed.

3 is an exploded perspective view showing the configuration of each part of the linear actuator according to the embodiment of the present invention.

4 is a perspective view showing the linear actuator according to the embodiment of the present invention, showing a state where a nut is in a protruding position.

5 is a schematic view showing a state in which a protruding portion of the linear actuator collides with a housing according to the embodiment of the present invention, and shows the state when viewed along the axial direction of the output shaft of the drive unit.

6 is a schematic view showing a state in which a protruding portion of a linear actuator in a modified example of the present invention collides with a case, and shows the state when viewed along the axial direction of the output shaft of the drive unit.

(Symbol Description)

1 linear actuator

10 drive unit

101 Main body

102 terminal blocks

11 output shaft

12 screw

13 Fixing plate

20 linear motion mechanism

21 nuts

22 protrusion

30 housing

30A first case

30A1 bottom wall

30A2～30A5 side wall

30A6 Partition

30A7 support wall

30A8 positioning protrusion

30B Second housing

30B1 bottom wall

30B2～30B5 side wall

31 The first storage department

32 The second storage part

321A First housing side recessed

321B First housing side recessed

detailed description

Next, a linear actuator according to an embodiment of the present invention will be described with reference to the drawings.

First, the structure of the linear actuator 1 according to the embodiment of the present invention will be described with reference to FIGS. 1 to 5 . The state of the position, FIG. 2 is a diagram showing the internal structure of the linear actuator 1 according to the embodiment of the present invention, and shows the state after the second housing 30B is removed, and FIG. 3 shows the linear actuator according to the embodiment of the present invention. Fig. 4 is a perspective view showing the linear actuator 1 according to the embodiment of the present invention, and shows the state where the nut 21 is in a protruding position. Fig. 5 shows the linear actuator according to the embodiment of the present invention. is a schematic diagram of a state in which the protruding part of the device collides with the housing, and shows the state when viewed along the axis direction of the output shaft of the drive part.

The linear actuator 1 of the present embodiment is a device capable of converting rotational motion into linear motion and outputting it. It has a substantially rectangular parallelepiped shape as a whole and includes a drive unit 10 , a linear motion mechanism 20 , and a housing 30 .

In addition, the driving unit 10 has a rotatable output shaft 11 and a lead screw 12 coaxially fixed to the output shaft 11 .

In addition, the linear motion mechanism 20 is driven by the driving part 10, and includes a nut 21 and a protrusion 22, wherein the nut 21 is screwed with the lead screw 12 in a manner capable of moving along the axis L of the output shaft 11, and the protrusion 22 is moved from the The shaft center side of the output shaft 11 is provided on the nut 21 so as to protrude outward in the radial direction of the output shaft 11 .

In addition, the housing 30 accommodates the drive unit 10 and the linear motion mechanism 20 , and has an opening 321 extending in the direction of the axis L of the output shaft 11 , and the protruding portion 22 is accommodated in the opening 321 .

In the present embodiment, the driving unit 10 includes a motor having an output shaft 11 . Specifically, the motor includes a main body 101 with a substantially cylindrical shape and a terminal block 102 protruding from the outer peripheral surface of the main body 101. The output shaft 11 protrudes from one end face of the main body 101, and the output A substantially rectangular fixing plate 13 is mounted on one side of the shaft 11 .

In addition, in the present embodiment, in the linear motion mechanism 20 , two protrusions 22 are provided on the nut 21 . Specifically, on the nut 21, two protruding parts 22 are provided at an angular interval of 180 degrees in the circumferential direction around the axis L of the output shaft 11. One side, and the distance between the front ends of the two protruding portions 22 is longer than the maximum inner diameter of the housing 30 (specifically, the second receiving portion 32 ). Furthermore, the two protruding portions 22 are plate-shaped, and an anti-seize protrusion 221 is respectively provided at an end portion of each protruding portion 22 on the side of the driving portion 10 .

In addition, in this embodiment, the housing 30 has a first storage portion 31 and a second storage portion 32, wherein the first storage portion 31 accommodates the drive unit 10, the second storage portion 32 accommodates the nut 21, and the second storage portion 32 has an opening 321 extending in the direction of the axis L of the output shaft 11 , and the protrusion 22 is accommodated in the opening 321 . Furthermore, in this embodiment, the housing 30 is divided into a first housing 30A and a second housing 30B along the axis L direction, and the opening 321 is formed on the mating surface of the first housing 30A and the second housing 30B. Specifically, the housing 30 has a generally rectangular parallelepiped box shape as a whole, and includes a first housing 30A and a second housing 30B, wherein the first housing 30A has a substantially rectangular bottom wall 30A1 and the surrounding area of the bottom wall 30A1 The side walls 30A2 to 30A5 standing vertically have a partition wall 30A6 parallel to the side walls 30A2 and 30A4 formed at the center of the bottom wall 30A1, and a partition wall 30A6 parallel to the side walls 30A2 and 30A4 is formed at the portion of the side walls 30A3 and 30A5 between the partition wall 30A6 and the side wall 30A4. The first housing side is recessed 321A. Correspondingly, the second housing 30B has a substantially rectangular bottom wall 30B1 and side walls 30B2-30B5 standing vertically from the periphery of the bottom wall 30B1, and on the bottom wall 30B1 A partition wall (not shown) corresponding to the partition wall 30A6 is formed, and a second housing-side recess 321B is formed on a part of the side walls 30B3 and 30B5 between the partition wall and the side wall 30B4, and the bottom of the first housing 30A is The wall 30A1, the side walls 30A2, 30A3, 30A5, the partition wall 30A6, the bottom wall 30B1, the side walls 30B2, 30B3, 30B5 of the second housing 30B, and the partition walls not shown constitute the first housing portion 31. The above-mentioned bottom wall 30A1, side walls 30A3 to 30A5, and partition wall 30A6 of 30A, and the above-mentioned bottom wall 30B1, side walls 30B3 to 30B5, and partition walls not shown in the second case 30B constitute the above-mentioned second housing portion 32, and the above-mentioned first case The body-side recess 321A and the second case-side recess 321B constitute the opening portion 321 . Here, on the bottom wall 30A1 of the first housing 30A, in addition to the partition wall 30A6, a support wall 30A7 and two positioning protrusions 30A8 are formed. The support wall 30A7 is formed between the side wall 30A2 and the partition wall 30A6. Two positioning protrusions 30A8 are respectively formed between the support wall 30A7 and the partition wall 30A6, and are respectively connected to the side walls 30A3 and 30A5. On the partition walls of the support wall 30A7, the partition wall 30A6 and the second housing 30B, there are respectively formed shapes corresponding to the shape of the motor. Corresponding to the recess, a recess corresponding to the shape of the nut 21 is formed on the side wall 30A4.

Next, assembly of the linear actuator 1 will be briefly described.

When assembling, it is necessary to assemble the driving part 10 and the linear motion mechanism 20 into the casing 30. At this time, for example, the driving part 10 and the linear motion mechanism 20 can be assembled into the first casing 30A, and then the second casing is covered. Two shells 30B.

Specifically, for example, the driving unit 10 can be attached to the open cavity formed by the bottom wall 30A1, side walls 30A2, 30A3, 30A5, and partition wall 30A6 of the first housing 30A, and the linear motion mechanism 20 can be attached to the first housing. 30A is an open cavity formed by the bottom wall 30A1, the side walls 30A3 to 30A5, and the partition wall 30A6. At this time, the motor can be supported on the support wall 30A7 and the partition wall 30A6 of the first housing 30A (specifically, the motor is supported in the respective depressions of the support wall 30A7 and the partition wall 30A6), and the fixing plate 13 is inserted into the positioning protrusion 30A8, Between 30A9 and the partition wall 30A6 of the first housing 30A, the protrusion 22 provided on the nut 21 is placed in the first housing side recess 321A, and the nut 21 is supported on the side wall 30A4 (specifically, the nut 21 is supported In the recess of the side wall 30A4), and then cover the second housing 30B, and make the first housing 30A and the second housing 30B be integrated into one body, for example, through a snap-fit structure, so as to complete the assembly.

In addition, after the linear actuator 1 is assembled, the nut 21 can move between the first position shown in FIG. 1 and the second position shown in FIG. 4 by being driven by the driving part 10 .

According to the linear actuator 1 according to the embodiment of the present invention, it is only necessary to provide the protruding part 22 on the nut 21 screwed with the lead screw 12 of the driving part 10, and to provide the opening 321 for accommodating the protruding part 22 on the housing 30. Since a conversion structure can be formed to convert the rotational motion output by the drive unit 10 into linear motion, the structure is simple. In addition, since the protrusion 22 of the nut 21 can be guided by the opening 321 of the case 30 when assembling the linear actuator 1 , it can be assembled with high precision.

Furthermore, according to the linear actuator 1 of the embodiment of the present invention, the distance from the axis L of the output shaft 11 to the front end of the protruding portion 22 is greater than the distance from the axis L of the output shaft 11 to the case 30 (specifically, the second housing portion 32 ). ) of the inner surface of the maximum distance to be longer. Therefore, when the linear motion mechanism 20 is mounted on the casing 30, if the assembly position of the linear motion mechanism 20 (the assembly angle of the nut 21 relative to the casing 30) is incorrect, as shown by the circle X in FIG. Since the front end portion 22a of the portion 22 interferes with the case 30, incorrect assembly can be avoided.

Furthermore, according to the linear actuator 1 of the embodiment of the present invention, two protrusions 22 are provided at angular intervals of 180 degrees in the circumferential direction around the axis L of the output shaft 11, and therefore, when the linear actuator 1 is driven, The force balance of the nut 21 in the circumferential direction around the axis L of the output shaft 11 is helpful to improve the output accuracy of the linear actuator 1 .

In addition, according to the linear actuator 1 of the embodiment of the present invention, the housing 30 is divided into the first housing 30A and the second housing 30B along the axis L direction, and the opening 321 is formed in the first housing 30A and the second housing 30A. 30B butt face. Therefore, when the linear motion mechanism 20 is installed in the housing 30 (specifically, the second housing portion 32), the nut 21 can be assembled in one of the first housing 30A and the second housing 30B, and then the cover can be closed. On the other hand, therefore, it is not difficult to assemble the linear motion mechanism 20 to the casing due to the protruding portion 22 provided on the nut 21 , which helps to improve the assembly efficiency.

In addition, according to the linear actuator 1 of the embodiment of the present invention, an anti-seize protrusion 221 is provided at the end of the protruding part 22 on the side of the driving part 10, which can reduce the contact area between the protruding part 22 and the housing 30, so , helps to prevent the protruding portion 22 from repeatedly colliding with the edge of the opening portion 321 of the housing 30 and thus helps to improve the working stability of the linear actuator 1 .

In addition, according to the linear actuator 1 of the embodiment of the present invention, the protruding part 22 is arranged on the side of the nut 21 close to the driving part 10, therefore, it is different from the method of disposing the protruding part 22 on the side of the nut 21 away from the driving part 10. Compared with the case, it helps to reduce the size of the linear actuator 1 .

The present invention has been exemplarily described above in conjunction with the accompanying drawings, and it is obvious that the specific implementation of the present invention is not limited by the foregoing embodiments.

For example, in the above embodiment, the housing 30 accommodates the drive unit 10 and the linear motion mechanism 20 , but the present invention is not limited thereto, and the housing 30 may accommodate only the linear motion mechanism 20 without housing the drive unit 10 .

In addition, in the above-mentioned embodiment, two protruding parts 22 are provided at an angular interval of 180 degrees in the circumferential direction around the axis L of the output shaft 11, but the present invention is not limited thereto, and only one protruding part 22 may be provided. In this case, only one opening 321 is required. In this case, as in the above-mentioned embodiment, when the linear motion mechanism 20 is installed in the second storage portion 32 of the housing 30, if the assembly position of the linear motion mechanism 20 (the assembly angle of the nut 21 relative to the housing 30 ) is incorrect, as shown by the circle Y in FIG. 6 , the front end portion 22a of the protruding portion 22 will interfere with the second receiving portion 32 of the housing 30, so that wrong assembly can be avoided. Of course, more than three protruding portions 22 can also be provided as required, and a corresponding number of openings 321 can be provided on the housing 30 .

In addition, in the above embodiment, the distance from the axis L of the output shaft 11 to the front end of the protruding portion 22 is longer than the maximum distance from the axis L of the output shaft 11 to the inner surface of the second housing portion 32 , but it does not Limited to this, if necessary, the distance from the axis L of the output shaft 11 to the front end of the protruding portion 22 may be set shorter than the maximum distance from the axis L of the output shaft 11 to the inner surface of the second housing portion 32 .

In addition, in the above-mentioned embodiment, the housing 30 is divided into the first housing 30A and the second housing 30B along the axis L direction, but it is not limited thereto, and the housing 30 may also be divided along the direction perpendicular to the axis L. .

In addition, in the above-mentioned embodiment, the anti-seize protrusion 221 is provided at the end of the protruding portion 22 on the side of the driving portion 10, but it is not limited thereto, and may also be provided on the end of the protruding portion 22 on the side away from the driving portion 10. An anti-seize protrusion is provided at the end, or an anti-seize protrusion is provided on both the end of the protruding part 22 on the side close to the driving part 10 and the end on the side away from the driving part 10 . Certainly, the anti-occlusion protrusion 221 may not be provided.

In addition, in the above embodiment, the protruding portion 22 is disposed on the side of the nut 21 close to the driving portion 10 , but the present invention is not limited thereto, and the position of the protruding portion 22 can be appropriately adjusted as required.

In addition, in the above-mentioned embodiment, the housing 30 is formed in a substantially rectangular parallelepiped box shape, but the present invention is not limited thereto, and the housing 30 may be formed in a cylindrical shape, for example.

In addition, the protruding portion 22 may be integrally formed with the nut 21 , or may be formed separately from the nut 21 .

Claims (9)

1. a kind of linear actuators (1), including：Drive division with revolvable output shaft (11) (10)；The straight-line motion mechanism (20) driven by the drive division (10)；And store the straight line The housing (30) of motion (20), it is characterised in that

The drive division (10) has leading screw (12), and the leading screw (12) is coaxially fixable to the output Axle (11),

The straight-line motion mechanism (20) includes：

Nut (21), the nut (21) with can along the output shaft (11) axis (L) direction move Dynamic mode is screwed togather with the leading screw (12)；And

Protuberance (22), the protuberance (22) is with from the center axis of the output shaft (11) towards described defeated The mode that the radial outside of shaft (11) is protruded is located at the nut (21),

The housing (30) has the opening portion that axis (L) direction along the output shaft (11) extends (321),

The protuberance (22) is accommodated in the opening portion (321).

2. linear actuators as claimed in claim 1, it is characterised in that

The housing (30) has：

Store the drive division (10) in first incorporating section (31), first incorporating section (31)；And

The nut (21) is stored in second incorporating section (32), second incorporating section (32),

Second incorporating section (32) has the opening portion (321).

3. linear actuators as claimed in claim 1, it is characterised in that

From the axis of the output shaft (11) to the distance ratio of the leading section of the protuberance (22) from institute The axis of output shaft (11) is stated to the storage straight-line motion mechanism (20) of the housing (30) The ultimate range of partial inner surface will be grown.

4. linear actuators as claimed any one in claims 1 to 3, it is characterised in that

The protuberance (22) is provided with multiple,

The opening portion (321) is with the protuberance (22) accordingly provided with multiple.

5. linear actuators as claimed in claim 4, it is characterised in that

The protuberance (22) is in the circumference around the axis of the output shaft (11) with 180 degree Angle is arranged at intervals with two,

Storage of the distance between the leading section of two protuberances (22) than the housing (30) The maximum inner diameter of the part of the straight-line motion mechanism (20) will be grown.

6. the linear actuators as any one of claim 1 to 5, it is characterised in that

The housing (30) is divided into the first housing (30A) and the second housing (30B) along the axis direction,

The opening portion (321) is formed at first housing (30A) and second housing (30B) Interface.

7. the linear actuators as any one of claim 1 to 5, it is characterised in that

The end by the drive division (10) side of the protuberance (22) is provided with anti-occlusion Projection (221).

8. the linear actuators as any one of claim 1 to 5, it is characterised in that

The protuberance (22) be arranged on the nut (21) by the one of the drive division (10) Side.

9. the linear actuators as any one of claim 1 to 5, it is characterised in that

The drive division (10) includes the motor with the output shaft (11).