JP3384438B2 - Linear motion device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a linear motion device which is preferably used for a vertical shaft or a traveling shaft of a robot or the like and which causes a moving member to perform a required linear motion by a screw action of a screw shaft and a nut member. .

[0002]

2. Description of the Related Art Conventionally, there is a linear motion device which causes a moving body to perform a required linear motion by a screw action of a screw shaft and a nut portion. The screw shaft has a male screw portion formed on the outer periphery thereof, and is rotationally driven by a motor or the like via a pulley, a timing belt, or the like. The nut portion has a female screw portion formed on the inner surface of the through hole, and the male screw portion of the screw shaft is screwed into the female screw portion. The moving body is fixed to the nut portion.

[0003]

In the above-described conventional linear motion device, the length of the nut portion of the screw shaft and the length of the fixed portion of the screw shaft are not directly related to the stroke amount capable of linear motion. The device dimension for the length is large compared to the stroke amount. Therefore, there is a problem that the total length of the device in the housed state becomes longer than the stroke amount and a dead space occurs. In other words, in order to obtain a predetermined stroke amount, it is necessary to secure a length equal to or larger than the stroke amount as a device space. For this reason, it is extremely difficult to secure the stroke amount, especially in a space with limited dimensions. INDUSTRIAL APPLICABILITY According to the present invention, the stroke amount capable of linear movement can be made longer than the total length of the device in the housed state, so that the dead space can be minimized and the maximum stroke can be achieved especially in a space having limited dimensions. It is an object of the present invention to provide a linear motion device that can secure the amount.

[0004]

The above object of the present invention is to form a male screw portion on the outer circumference and to form a first screw shaft having only a base end portion fixed to a base member and an inner surface of a through hole. A first screw shaft to which the male screw portion of the first screw shaft is screwed
Of the first nut member and the first nut member are rotatably supported by the first nut member, and the first nut member and the first screw shaft are screwed together by the screw action of the first nut member and the first screw member. A first moving member that is moved along a screw axis of 1 and a male screw portion is formed on the outer periphery, and only a base end portion is fixed to the first moving member and relatively rotated with respect to the first moving member. A second nut member that is movably supported, a second nut member in which a male screw portion of the second screw shaft is screwed into a female screw portion formed on the inner surface of the through hole, and the second nut member. A second screw shaft fixed to the nut member and moved along the second screw shaft by a screw action of the second screw shaft and the second nut shaft accompanying the rotation of the second screw shaft. The rotation of the moving member and the drive pulley fixed to the rotating shaft of the motor is rotated by a belt to rotate the first pulley. By transmitting the rotation of the drive pulley fixed to the rotation shaft of the motor to the driven pulley fixed to the second screw shaft through the belt while transmitting the rotation to the driven pulley fixed to the member, This is achieved by a linear motion device provided with a nut member and a drive means for rotating the second screw shaft in synchronization. The linear motion device may include a guide member that is fixed to the first moving member, is relatively movable with respect to the base member, and is connected to the second moving member so as to be relatively movable. preferable. The guide member moves along with the movement of the first moving member along the first screw axis to cause the first moving member to move.
Of the second moving member in the same direction, and the second moving member is moved relative to the second moving member along the second screw axis. In the linear motion device according to the present invention, the first nut member and the second screw shaft are rotated synchronously by the driving means. First
The nut member causes a screw action between the nut member and the first screw shaft as the nut member rotates. Thereby, the first moving member is moved along the first screw shaft. The second
The screw shaft causes a screw action with the second nut member as the drive shaft rotates. Thereby, the second moving member is moved along the second screw shaft. The guide member moves in the same direction in conjunction with the first moving member along with the movement of the first moving member along the first screw shaft, and also moves on the second screw shaft of the second moving member. The second moving member is relatively moved and guided along with the movement.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 is a side view showing a housed state of a linear motion device according to an embodiment of the present invention.
[Fig. 2] is a side view showing an extended state of the linear motion device of Fig. 1. In these drawings, the first nut member 21 and the second screw shaft 30 are synchronously rotated by the motor 40, and between the first nut member 21 and the first screw shaft 20,
Also, a screw action is generated between the second screw shaft 30 and the second nut member 32. Thereby, the first moving member 23,
While being moved along the first screw shaft 20, the second moving member 34 is moved along the second screw shaft 30,
From the predetermined storage position (the position shown in Fig. 1) to the extended position (Fig. 2)
(The position shown in FIG. 2) or from the extended position to the stored position. A male screw portion (not shown) is formed on the outer periphery of the first screw shaft 20, and the base end portion is fixed to the bottom portion 11 of the storage case 10 which is a base member. In the first nut member 21, the male screw portion of the first screw shaft 20 is screwed into a female screw portion (not shown) formed on the inner surface of the through hole 22. The first nut member 21 includes a first moving member 23.
Are rotatably supported by bearings 24. First
The moving member 23 of the first nut member 21 is formed in a flat plate shape, for example, and is rotated by the rotation of the first nut member 21.
By the screw action of the first screw shaft 20 and the first screw shaft 20, the first retracted position to the extended position, or the extended position to the retracted position, the first
The screw shaft 20 is moved in the vertical direction in the figure. Second
The screw shaft 30 has a male screw portion (not shown) formed on the outer periphery thereof, and is supported by the first moving member 23 via a bearing 31 so as to be relatively rotatable substantially parallel to the first screw shaft 20. It In the second nut member 32, the male screw portion of the second screw shaft 30 is screwed into a female screw portion (not shown) formed on the inner surface of the through hole 33. The second nut member 32 fixes the second moving member 34 by being fitted into the fitting groove 35 of the second moving member 34. The second moving member 34 is
For example, it is formed in a cubic shape, and due to the screw action of the second screw shaft 30 and the second nut member 32 accompanying the rotation of the second screw shaft 30, from the predetermined storage position to the extended position or from the extended position. It is moved up and down in the figure along the second screw shaft 30 to the storage position. A robot arm 36 is attached to the upper surface of the second moving member 34 in the figure. The robot arm 36 operates, for example, as a vertical axis of the robot at the extended position of the second moving member 34. The first nut member 21 and the second screw shaft 30 are driven by the driven pulley 4
2, 45, drive pulleys 44 and 47, and timing belts 43 and 46, the motor 40 is synchronously driven to rotate in a predetermined direction. The motor 40 is fixed to the center of the first moving member 23 in the drawing with the rotating shaft 41 facing downward in the drawing. That is, the first nut member 2
1 is interlocked with the motor 40 via a driven pulley 42, a timing belt 43, and a drive pulley 44. The driven pulley 42 is fixed to the lower end of the first nut member 21 in the figure. The drive pulley 44 is fixed to the rotating shaft 41 of the motor 40. The timing belt 43 is driven by the driven pulley 42.
And the drive pulley 44. The second
The screw shaft 30 of the driven pulley 45, the timing belt 4
6 and the drive pulley 47, and is linked with the motor 40. The driven pulley 45 is fixed to the lower end of the second screw shaft 30 in the figure. The drive pulley 47 is the drive pulley 44.
It is integrally formed with and is fixed to the rotating shaft 41 of the motor 40. The timing belt 46 is wound around the driven pulley 45 and the drive pulley 47. The lower end of the linear guide 50 in the figure is fixed to the upper surface of the left end in the figure of the outer peripheral portion 25 of the first moving member 23. The linear guide 50 has guide grooves 51 and 53 formed on both left and right side surfaces in the drawing, and the storage case 10 and the second moving member 34 are provided in the guide grooves 51 and 53, respectively.
2, 54 are attached so as to be movable relative to each other. That is, the linear guide 50 is supported on the inner left side surface of the storage case 10 in the drawing through the guide groove 51 and the bearing 52 on the left side surface of the drawing so as to be relatively movable in the vertical direction in the drawing, and
Second through the guide groove 53 and the bearing 54 on the right side in the drawing
Of the moving member 34 of FIG. The linear guide 50 includes the first screw shaft 20 of the first moving member 23.
Along with the movement in the vertical direction in the drawing, the first moving member 2
Move in the same direction in conjunction with 3. Also linear guide 50
Guides the second moving member 34 by moving the second moving member 34 in the vertical direction in the drawing relative to the movement of the second moving member 34 in the vertical direction in the drawing along the second screw shaft 30. The operation of this embodiment will be described below. First and second moving members 23, 34
However, for example, when the linear movement (extension operation) is performed from the predetermined storage position shown in FIG. 1 to the predetermined extension position shown in FIG. 2, the first nut member 21 and the second screw shaft 30 move the motor 4
It is rotated in a predetermined direction in synchronization with the normal rotation of 0. That is, the first nut member 21 causes a screw action with the first screw shaft 20 as the motor 40 rotates in a predetermined direction. As a result, the first moving member 23 is moved upward in the drawing along the first screw shaft 20. Further, the second screw shaft 30 causes a screw action with the second nut member 32 as the motor 40 rotates in a predetermined direction. As a result, the second moving member 34 is moved upward in the drawing along the second screw shaft 30. At this time, the linear guide 50 uses the first screw shaft 20 of the first moving member 23.
Along with the upward movement in the drawing, the first moving member 23
In the same direction as the second moving member 34 moves upward in the drawing along the second screw shaft 30 and the second moving member 34 moves relatively upward in the drawing. To guide you. In a state where the first and second moving members 23 and 34 are linearly moved to a predetermined extension position, the robot arm 36 attached to the second moving member 34 operates, for example, as a vertical axis of the robot. The first and second
When the moving members 23 and 34 are linearly moved (stored) from the predetermined extended position shown in FIG. 2 to the predetermined stored position shown in FIG. 1, the first nut member 21 and the second screw shaft The reverse rotation of the motor 40 causes the motor 30 to rotate in a direction opposite to that of the extension operation (hereinafter, simply referred to as reverse direction). The first nut member 21 causes a reverse screw action with the first screw shaft 20 as the motor 40 rotates in the reverse direction. As a result, the first moving member 23
Are moved downward in the figure along the first screw shaft 20.
Further, the second screw shaft 30 causes a reverse screw action with the second nut member 32 as the motor 40 rotates in the reverse direction. Thereby, the second moving member 34 is
It is moved downward in the figure along the second screw shaft 30. At this time, the linear guide 50 moves in the same direction in conjunction with the first moving member 23 as the first moving member 23 moves downward in the drawing along the first screw shaft 20, and Second
The second moving member 34 is relatively moved downward and guided along with the movement of the moving member 34 downward along the second screw shaft 30 in the drawing. First and second moving members 23, 34
However, each component except the robot arm 36 is stored in the storage case 10 in a state where it is returned to the predetermined storage position. As described above, according to the above embodiment, the first
Between the nut member 21 and the first screw shaft 20 and the second
Of the first moving member 23 by the screw action generated between the screw shaft 30 and the second nut member 32 of the first screw shaft 2.
0 along with the second moving member 34
Are moved along the second screw shaft 30. That is,
Two screw shafts 20 and 30 and two moving members 23 and 34
By adopting a two-stage extension structure as described above, each stage is responsible for approximately half of the stroke amount A capable of linear movement. Therefore, the stroke amount A capable of linear operation can be made longer than the total length B of the device in the stored state (stroke amount A> total length B in the stored state). This makes it possible to secure the maximum stroke amount A while minimizing the dead space, especially in a narrow space of which dimensions are restricted. Further, the linear guide 50 moves along with the movement of the first moving member 23 along the first screw shaft 20,
While moving in the same direction in conjunction with the first moving member 23, the second moving member 34 is relatively moved and guided along with the movement of the second moving member 34 along the second screw shaft 30. . Therefore, it is possible to reliably prevent rattling and the like of each part due to the two-stage extension structure. In recent years, for devices installed in a clean room such as a clean robot, compactness and a wide operating range are required to be compatible. The device of the present embodiment can meet such conflicting requirements. In the above embodiment, between the linear guide 50 and the storage case 10,
And between the linear guide 50 and the second moving member 34,
The bearings 52 and 54 are respectively interposed. However, depending on the size and weight of the device, the bearings 52, 5
If only 4, the mutual support between the respective members becomes unstable, and there is a risk that relative inclination or the like may occur between the respective members. Considering such a case, it is also possible to use another guide member (not shown) for guiding each member so as to ensure a mutual support between the members.

[0006]

As described above, according to the present invention, the first nut member and the second screw shaft are rotated in synchronization with each other by the drive means, and the first nut member and the first screw shaft are rotated. while,
And a screw action is generated between the second screw shaft and the second nut member. As a result, the first moving member is moved along the first screw shaft and the second moving member is moved along the second screw shaft. Therefore, the stroke amount capable of linear movement can be made longer than the total length of the device in the housed state. As a result, it is possible to secure the maximum stroke amount while minimizing the dead space, particularly in a space with limited dimensions. In addition, the guide member moves in the same direction in conjunction with the first moving member along with the movement of the first moving member along the first screw shaft, and also the second screw shaft of the second moving member. The second moving member is relatively moved along with the movement along.
Therefore, it is possible to reliably prevent rattling and the like of each part due to the movement of each moving member.

[Brief description of drawings]

FIG. 1 is a side view showing a housed state of a linear motion device according to an embodiment of the present invention.

FIG. 2 is a side view showing an extended state of the linear movement device of FIG.

[Explanation of symbols]

10 Base member (storage case) 20 First screw shaft 21 First Nut Member 23 First moving member 24 bearing 30 Second screw shaft 31, 52, 54 bearings 32 Second nut member 34 Second moving member 36 robot arm 40 Drive means (motor) 41 Drive means (rotating shaft) 42 Drive means (driven pulley) 43 Drive means (timing belt) 44 Drive means (drive pulley) 45 Drive means (driven pulley) 46 Drive means (timing belt) 47 Drive means (drive pulley) 50 Guide member (linear guide)

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) B25J 9/06 H01L 21/68

Claims (2)

(57) [Claims] 1. A male screw portion is formed on the outer periphery, and only a base end portion is formed.
A first screw shaft fixed to the base member; a first nut member in which a male screw portion of the first screw shaft is screwed into a female screw portion formed on the inner surface of the through hole; 1 is rotatably supported by the first nut member, and the first nut member and the first screw shaft are screwed by the rotation of the first nut member. a first moving member moved, the male screw portion is formed on an outer periphery, the second only base end portion is rotatably supported on said first moving member is fixed to the first moving member A second nut member having a male screw portion of the second screw shaft screwed into a female screw portion formed on the inner surface of the through hole, and fixed to the second nut member, Due to the screw action of the second screw shaft and the second nut member accompanying the rotation of the second screw shaft, A second moving member that is moved along the screw shaft of No. 2, and the rotation of a drive pulley that is fixed to the rotation shaft of the motor, is transmitted to a driven pulley that is fixed to the first nut member via a belt, Synchronizing the first nut member and the second screw shaft by transmitting the rotation of the drive pulley fixed to the rotation shaft of the motor to the driven pulley fixed to the second screw shaft via the belt. And a driving means for rotating the linear movement device. 2. A guide member, which is fixed to the first moving member, is movable relative to the base member, and is connected to the second moving member so as to be relatively movable, Moves in the same direction in conjunction with the movement of the first moving member along the first screw axis in the same direction as the second moving member, and moves in the same direction as the second moving member. The linear movement device according to claim 1, wherein the second moving member is relatively moved along with the movement along the screw axis.