KR101999267B1 - Shaft direction force measurable screw driving apparatus - Google Patents

Abstract

A screw driving device capable of measuring axial force is disclosed. A screw drive device capable of measuring the axial force disclosed comprises: a base; A motor fixed to the base and transmitting rotational force to the drive shaft; A drive shaft that receives the rotational force from the motor and rotates; A feed nut assembly coupled to the drive shaft and being transported along an axial direction of the drive shaft; A pair of bearings for supporting both ends of the drive shaft; A pair of bearing supports fixed to the base and supporting the pair of bearings; And an axial force measurement sensor coupled to the drive shaft to measure an axial force of the drive shaft. When the motor is driven, the axial force acting on the drive shaft can be measured by the axial force measurement sensor.

Description

[0001] The present invention relates to a screw driving apparatus capable of measuring an axial force,

The present invention relates to a screw driving device capable of measuring an axial force, and more particularly, to an axial force measuring sensor for precisely measuring a driving force of a screw driving device in the direction of a driving shaft, between a feeding nut and a feeding nut casing on a driving shaft, The present invention relates to a screw driving apparatus capable of measuring an axial force by detecting an abnormal operation of a screw driving apparatus by interposing between a bearing cap and a bearing bracket and enhancing the stability of the apparatus and the convenience of maintenance.

The screw driving device is used in various fields such as machine tools, automation equipment, and semiconductor production equipment since the structure is simple, while transferring the object to be transferred quickly and accurately.

Such a screw driving device is composed of a motor that provides a driving force, a driving shaft that is coupled to the motor and rotates, and a nut that is coupled to the driving shaft to be transported. Adjustment of the feed speed and feed direction of the screw driving device can be easily implemented by controlling the driving motor.

The screw drive may overload the drive shaft due to various reasons such as breakage or damage of the drive during driving, jamming due to foreign matter, interference between devices, and the like. Failure to immediately take appropriate measures could result in serious damage to the entire equipment to which the screw drive is applied.

For this purpose, it is necessary to monitor the driving load of the screw driver in real time. The most important factor of the driving load of the screw driving device is the driving force acting in the axial direction of the driving shaft.

In the conventional screw driving apparatus, in order to measure the axial transferring force, the torque of the driving motor is measured and converted into an axial force, or a transfer force in a direction perpendicular to the driving shaft is measured and then converted into axial force .

However, there is a problem that accuracy is low because measurement error can be reflected when measuring by such an indirect method.

On the other hand, if design changes are made to the drive shaft and the nut itself to directly measure the axial transfer force of the screw drive, the problem of the strength and the existing design data can not be utilized.

Therefore, it is urgently required to develop an improved screw drive device capable of directly measuring the axial transfer force of the drive shaft without making a design change to the drive shaft and the nut itself.

Korean Patent Publication No. 10-2001-0033675

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to directly measure an axial transfer force of a screw driving device.

Another object of the present invention is to provide a screw driving device for measuring an axial direction transferring force of a drive shaft without changing a design of a drive shaft and a nut itself.

It is another object of the present invention to provide a design and mounting structure of an axial force sensor for directly measuring an axial force of a screw driving device.

The present invention relates to a semiconductor device, A motor fixed to the base and transmitting rotational force to the drive shaft; A drive shaft that receives the rotational force from the motor and rotates; A feed nut assembly coupled to the drive shaft and being transported along an axial direction of the drive shaft; A pair of bearings for supporting both ends of the drive shaft; A pair of bearing supports fixed to the base and supporting the pair of bearings; And an axial force measurement sensor coupled to the drive shaft to measure an axial force of the drive shaft,

And the axial force acting on the drive shaft can be measured by the axial force measurement sensor when the motor is driven.

The feed nut assembly according to the present invention may further include a feed nut coupled to the drive shaft and fed along the drive shaft as the drive shaft rotates; And a conveying nut casing for conveying the driving shaft with the conveying nut, and a table on which an object to be conveyed is coupled,

The axial force measuring sensor includes a first through hole through which the drive shaft is coupled, and is interposed between the feed nut and the feed nut casing, and is fastened to the feed nut and the feed nut casing.

The feed nut assembly of the present invention is formed in a ring shape having a hollow portion therein and is conveyed along a drive shaft when the drive shaft rotates and is coupled to the drive shaft. And a transfer nut casing for transferring the drive shaft phase together with the transfer nut, and a table on which an object to be transferred is coupled,

And the axial force measuring sensor is embedded in the hollow portion of the feed nut.

Further, among the pair of bearing supports of the present invention, the bearing support mounted on the motor side is fastened to the drive shaft in tight contact with one side of the bearing coupled to the stepped portion formed on the drive shaft, A bearing cap; A bearing fixing member coupled to the drive shaft in a state of being in close contact with the other side of the bearing to prevent the bearing from coming off; And a bearing bracket surrounding the bearing and supporting the bearing,

The axial force measurement sensor includes a flange portion having a second through hole formed at a center thereof and perpendicular to the drive shaft, a body portion formed in a pipe shape in the direction of the drive shaft in series with the inner peripheral surface of the flange portion, And a bent portion bent toward the drive shaft in a direction perpendicular to the drive shaft,

Wherein a flange portion of the axial force measuring sensor is interposed between the bearing cap and the bearing bracket and is fastened to the bearing cap and the bearing bracket and the body portion of the axial force measurement sensor is formed between the inner circumferential surface of the bearing bracket and the outer circumferential surface of the bearing, And the bent portion of the axial force sensor is tightly coupled to the other side of the bearing.

In addition, the present invention provides a motor comprising: a motor flange having a third through hole through which a motor shaft passes, a motor flange coupled to one side of the motor while being fixed to the base, And a coupling coupled to the motor shaft at one end and coupled to the drive shaft at another end to transmit the rotational force of the motor to the drive shaft.

The present invention further includes a controller for comparing the axial force value received from the axial force sensor with a predetermined standard axial force value and then generating a control signal for the motor.

The screw driving device according to the present invention has the effect of directly measuring the axial direction transfer force to reduce the measurement error.

Also, the screw driving apparatus according to the present invention has an effect of measuring the axial direction transfer force without changing the design of the driving shaft and the nut driving unit.

Further, the screw driving device according to the present invention has an effect of providing a mounting structure of an axial force measuring sensor.

The above and other objects, features and advantages of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG.

1 is a perspective view of a conventional screw driving device.
2 is a perspective view of a first embodiment of a screw driving apparatus according to the present invention.
FIG. 3 is an exploded perspective view of a main portion of a screw driving apparatus according to a first embodiment of the present invention. FIG.
4 is a view for explaining axial force transmission in the first embodiment of the screw driving device according to the present invention.
5 is a cross-sectional view of a main part of a second embodiment of the screw driving device according to the present invention.
6 is a perspective view of a third embodiment of the screw driving apparatus according to the present invention.
FIG. 7 is an exploded perspective view of a main part of a third embodiment of the screw driving device according to the present invention. FIG.
8 is a view for explaining the axial force transmission in the third embodiment of the screw driving device according to the present invention.

Hereinafter, various embodiments of the present document will be described with reference to the accompanying drawings. It should be understood, however, that the techniques described herein are not intended to be limited to any particular embodiment, but rather include various modifications, equivalents, and / or alternatives of the embodiments of this document. In connection with the description of the drawings, like reference numerals may be used for similar components.

Also, the terms "first," "second," and the like used in the present document can be used to denote various components in any order and / or importance, and to distinguish one component from another But is not limited to those components. For example, 'first part' and 'second part' may represent different parts, regardless of order or importance. For example, without departing from the scope of the rights described in this document, the first component can be named as the second component, and similarly the second component can also be named as the first component.

It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the other embodiments. The singular expressions may include plural expressions unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art. The general predefined terms used in this document may be interpreted in the same or similar sense as the contextual meanings of the related art and, unless expressly defined in this document, include ideally or excessively formal meanings . In some cases, even the terms defined in this document can not be construed as excluding the embodiments of this document.

1 is a perspective view of a conventional screw driving device.

Will be described with reference to Fig.

Fig. 1 is a screw drive device 10 which is generally used, in which the axial force measuring sensor is not mounted. Since the present invention shares a basic configuration with a conventional screw driving apparatus 10 as shown in FIG. 1, the structure of the screw driving apparatus 10 shown in FIG. 1 will be described.

The screw drive apparatus 10 includes a base 100, a motor 110, a drive shaft 120, a feed nut assembly 200, a bearing 300, and a bearing support 400.

On the upper surface of the base 100, a motor 110 for transmitting rotational force to the driving shaft 120 is mounted.

The drive shaft 120 is rotated by receiving a rotational force from the motor 110 and the transfer nut assembly 200 is coupled to the drive shaft 120.

The feed nut assembly 200 moves forward or backward on the drive shaft 120 as the drive shaft 120 rotates.

The feed nut 210 included in the feed nut assembly 200 may be a ball screw nut or a lead screw nut. However, the type of the transfer nut 210 is not limited thereto.

A table 230 on which an object to be transferred is mounted may be mounted on the upper part of the transfer nut assembly 200.

A guide block is coupled to the lower portion of the table 230 to allow the table 230 to be conveyed in a stable manner along the conveying axis. The guide block runs on a guide rail disposed parallel to both sides of the drive shaft 120.

Both ends of the drive shaft 120 are rotatably supported by a pair of bearings. The bearing 300 used here is a radial bearing that supports a load in the radial direction of the bearing 300, i.e., in a direction perpendicular to the drive shaft 120. [

A pair of bearings 300 are supported by a bearing support 400 and the bearing support 400 is fixed to the base 100.

In the present invention, an axial direction transmitting force is supported by a bearing support which is tightly coupled to a radial bearing.

However, thrust bearings may be employed, in which case the thrust bearings can directly support the axial transfer force.

In order to monitor the operating state of the screw driving device 10 operated with such a structure, it is necessary to first measure the axial direction transferring force of the driving shaft 120, that is, the axial direction force.

As the motor 110 rotates, the drive shaft 120 rotates and the transfer nut assembly 200 coupled to the drive shaft 120 receives a force in the axial direction of the drive shaft 120 from the drive shaft 120. According to the present invention, a screw driving apparatus 10 capable of measuring the axial force is disclosed.

FIG. 2 is a perspective view of a first embodiment of a screw driving apparatus 10 according to the present invention, FIG. 3 is an exploded perspective view of a main portion of a screw driving apparatus 10 according to the first embodiment of the present invention, 1 is a view for explaining axial force transmission in the first embodiment of the screw drive device 10 according to the present invention;

A first embodiment of the screw driving apparatus 10 according to the present invention will be described with reference to Figs. 2 to 4. Fig.

In the present invention, the axial transfer force of the driving shaft 120 is directly measured by a sensor to obtain a driving load without additional calculation.

As the drive shaft 120 rotates, the drive shaft 120 transfers the axial transfer force directly to the transfer nut assembly 200. Accordingly, in the first embodiment of the present invention, the axial force measurement sensor 500a is mounted on the transfer nut assembly 200.

The feed nut assembly 200 according to the present invention includes a feed nut 210 and a feed nut casing 220.

The feed nut 210 is coupled to the drive shaft 120 and is transported along the drive shaft 120 as the drive shaft 120 rotates.

The transfer nut casing 220 transfers the driving shaft 120 together with the transfer nut 210, and the table 230 on which the transfer object is disposed is coupled to the upper part.

The axial force sensor 500a according to the first embodiment of the present invention has a first through hole 510a through which a drive shaft 120 is coupled through a center, and is formed in a flat plate shape. However, the shape of the axial force sensor 500a is not limited to this, and various shapes can be manufactured in consideration of the installation space.

The axial force sensor 500a is interposed between the feed nut 210 and the feed nut casing 220 and is fastened to the feed nut 210 and the feed nut casing 220.

The axial force transmitted from the drive shaft 120 to the feed nut 210 is transmitted to the axial force measurement sensor 500a coupled to the feed nut 210. Therefore, (500a).

Since the axial force sensor 500a of the first embodiment can be fastened without deforming the design of the drive shaft 120 or the feed nut 210, existing design data can be utilized.

4 (a) is a view for explaining a delivery path of the delivery force when the delivery nut 210 is transported to the right, and Fig. 4 (b) Fig.

Fig. 5 is a sectional view of the main part of the second embodiment of the screw driving apparatus 10 according to the present invention.

Will be described with reference to FIG.

The second embodiment is a modified embodiment of the first embodiment in which the axial force measurement sensor 500b is built inside the feed nut 210. [

The feed nut 210 and the feed nut casing 220 can be directly assembled to each other in the case of the feed nut 210 having a hollow portion having a hollow portion therein.

FIG. 6 is a perspective view of a third embodiment of the screw driving apparatus 10 according to the present invention, FIG. 7 is an exploded perspective view of the third embodiment of the screw driving apparatus 10 according to the present invention, Fig. 7 is a view for explaining axial force transmission in the third embodiment of the screw drive device 10 according to the present invention. Fig.

Will be described with reference to Figs. 6 to 8. Fig.

As the drive shaft 120 rotates, the axial direction transfer force of the drive shaft 120 is directly transmitted to the side surface of the bearing 300. Therefore, in the third embodiment of the present invention, the bearing 300 is mounted closely to the axial force sensor 500c.

The bearing 300 can be mounted at both ends of the driving shaft 120, but the bearing supporting structure of the third embodiment according to the present invention has a both-end fixing-supporting structure. In other words, one end of the drive shaft supports the rail diverting and axially transmitting force, and the other end of the drive shaft supports only the radial direction transmitting force.

However, in a machine tool or the like, it is possible to use a bearing support structure having both-end fixed-fixed structure. In such a case, it is of course possible to measure the axial direction transfer force even if an axial force sensor is provided on either side.

At both ends of the driving shaft 120, a bearing 300 for supporting the driving shaft 120 is mounted and a stepped portion is formed for transmitting the axial force of the driving shaft 120.

The bearing 300 is coupled to the stepped portion of the drive shaft 120 on the motor 110 side. A bearing cap 410 is fastened to the driving shaft 120 in a state of being closely attached to one side of the bearing 300 in order to prevent the bearing 300 from separating from the one side of the bearing 300.

A bearing fixing member 420 is fastened to the driving shaft 120 in a state of being in close contact with the other side of the bearing 300 in order to prevent the bearing 300 from separating from the other side of the bearing 300.

The bearing fixing member 420 may be formed as a single member, but may be made of a color 421 and a lock nut 422 for fastening convenience.

Next, a bearing bracket 430 supporting the bearing 300 is disposed so as to surround the bearing 300.

An axial force sensor 500c for measuring the axial force is disposed between the bearing cap 410 and the bearing bracket 430. [

The axial force sensor 500c according to the third embodiment includes a flange portion 520c, a body portion 530c, and a bent portion 540c.

The flange portion 520c has a second through hole 510c formed at the center thereof and is formed in a direction perpendicular to the driving shaft 120. [

The body portion 530c is formed in the shape of a pipe in the direction of the driving shaft 120 after continuing to the inner peripheral surface of the flange portion 520c.

The bent portion 540c is formed at one end of the body portion 530c by being bent toward the driving shaft 120 in a direction perpendicular to the driving shaft 120. [

The coupling relationship of the axial force measurement sensor 500c formed in such a structure will be described.

The flange portion 520c of the axial force sensor 500c is interposed between the bearing cap 410 and the bearing bracket 430 to be fastened to the bearing cap 410 and the bearing bracket 430. [ At this time, the bearing cap 410, the flange portion 520c, and the bearing bracket 430 can be fastened by one fastening means. The bearing cap 410 and the flange portion 520c may be fastened by one fastening means and the flange portion 520c and the bearing bracket 430 may be fastened by other fastening means.

The body portion 530c of the axial force sensor 500c is formed between the inner circumferential surface of the bearing bracket 430 and the outer circumferential surface of the bearing 300. [

The bent portion 540c of the axial force sensor 500c is tightly coupled to the other side of the bearing 300. [

8 (a) is a view for explaining an axial direction force transmission when the axial direction transmitting force is on the right side, and FIG. 8 (b) is a view for explaining the axial direction force transmission when the axial direction transmitting force is acting on the left side to be.

8A, the drive shaft 120 rotates so that the stepped portion on the drive shaft 120 transmits an axial force to one side surface of the bearing 300, and the bearing 300 is positioned on the other side of the bearing 300 And transmits an axial force to the bent portion 540c of the tightened axial force measurement sensor 500c. As a result, the axial force along the rotation of the drive shaft 120 can be accurately measured by the axial force measurement sensor 500c.

The bearing fixing member 420 coupled to the driving shaft 120 by the driving shaft 120 rotates to transmit an axial force to the other side of the bearing 300, The axial force is transmitted to the bearing cap 410 coupled to one side of the bearing 300. Since the bearing cap 410 is fastened to the axial force measurement sensor 500c by the fastening means, the axial force is accurately transmitted to the axial force measurement sensor 500c.

As a result, the axial force can be accurately measured by the axial force measurement sensor 500c in both the forward and reverse directions of the drive shaft 120. [

A motor flange 130 is provided to support the motor 110.

The motor flange 130 has a third through hole 130a through which the motor shaft 110a passes and is coupled to one side of the motor 110 while being fixed to the base 100. [

A coupling 140 for transmitting the rotational force of the motor 110 to the driving shaft 120 may be provided.

One side of the coupling 140 is coupled to the motor shaft 110a and the other side is coupled to the driving shaft 120 to transmit the rotational force of the motor 110 to the driving shaft 120.

The screw driver 10 according to the present invention may further include a controller.

The controller compares the axial force value received from the axial force measurement sensor 500c with a predetermined standard axial force value and then generates a control signal for the motor 110. [ When the abnormal load is detected in the axial force sensor 500c, the speed of the motor 110 can be adjusted to cope with equipment damage.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is clearly understood that the same is by way of illustration and example only and is not to be construed as limiting the scope of the invention as defined by the appended claims. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention.

Screw driver 10
Base 100
Motor 110
The motor shaft 110a
Drive shaft 120
Motor flange 130
The third through hole 130a
Coupling 140
Feed nut assembly 200
Feed nut 210
Feed nut casings 220
Table 230
Bearing 300
Bearing support 400
Bearing cap 410
The bearing fixing member 420
Color 421
Lock nut 422
Bearing bracket 430
Axial force measuring sensor 500a
The first through hole 510a
Axial force measuring sensor 500b
Axial Force Sensor 500c
The second through hole 510c
The flange portion 520c
The body portion 530c
The bent portion 540c

Claims (6)

A base 100;
A motor 110 fixed to the base 100 and transmitting rotational force to the driving shaft 120;
A driving shaft 120 that receives the rotational force from the motor 110 and rotates;
A transfer nut assembly 200 coupled to the drive shaft 120 and transferred along an axial direction of the drive shaft 120;
A pair of bearings 300 for supporting both ends of the driving shaft 120;
A pair of bearing supports (400) fixed to the base (100) and supporting the pair of bearings (300);
And axial force measurement sensors (500a, 500b, 500c) coupled to the drive shaft (120) to measure an axial force of the drive shaft (120)
The axial force acting on the drive shaft 120 can be measured by the axial force measurement sensors 500a, 500b and 500c when the motor 110 is driven,
The bearing support 400 mounted on the motor 110 side of the pair of the bearing supports 400,
A bearing cap 410 fastened to the drive shaft 120 in a state of being in close contact with one side of the bearing 300 coupled to the stepped portion formed on the drive shaft 120 to prevent the bearing 300 from coming off;
A bearing fixing member 420 fastened to the driving shaft 120 in a state of being closely attached to the other side of the bearing 300 to prevent the bearing 300 from being separated;
And a bearing bracket (430) surrounding the bearing (300) and supporting the bearing (300)
The axial force sensor 500c includes a flange portion 520c formed at the center thereof with a second through hole 510c and formed in a direction perpendicular to the driving shaft 120 and a flange portion 520c formed in the inner peripheral surface of the flange portion 520c, A bending portion 540c bent toward the driving shaft 120 in a direction perpendicular to the driving shaft 120 at one end of the body portion 530c; Including,
The flange 520c of the axial force sensor 500c is interposed between the bearing cap 410 and the bearing bracket 430 to be coupled to the bearing cap 410 and the bearing bracket 430, The body portion 530c of the bearing 500c is interposed between the inner circumferential surface of the bearing bracket 430 and the outer circumferential surface of the bearing 300 and the bent portion 540c of the axial force measurement sensor 500c contacts the bearing 300, (10) capable of measuring an axial force of the screw driving device (10) delete delete delete The method according to claim 1,
A third through hole 130a through which the motor shaft 110a passes is formed at the center and is coupled to one side of the motor 110 while being fixed to the base 100, (130);
And a coupling 140 coupled to the motor shaft 110a at one side and coupled to the drive shaft 120 at the other side to transmit the rotational force of the motor 110 to the drive shaft 120. [ A screw drive (10) capable of measuring the axial force, The method according to claim 1,
Further comprising a controller for comparing the axial force value received from the axial force measurement sensors (500a, 500b, 500c) with a predetermined standard axial force value and then generating a control signal for the motor (110) (10) capable of measuring the position of the screw

Images