KR102370683B1 - Apparatus for supporting a ball screw - Google Patents

Abstract

The ball screw support device may include a first bearing unit, a second bearing unit and a pressing unit. The first bearing unit may rotatably support one end of the ball screw, and fix one end of the ball screw so that one end of the ball screw does not move in an axial direction of the ball screw. The second bearing unit may rotatably support the other end of the ball screw. The pressing unit may selectively press the second bearing unit to fix the other end of the ball screw so that the other end of the ball screw does not move in the axial direction. Accordingly, one end of the ball screw is always fixed but the other end can be selectively fixed by the pressing unit, so that the supporting device can be selectively switched from the fixed-support method to the fixed-fix method.

Description

Ball screw support device {APPARATUS FOR SUPPORTING A BALL SCREW}

The present invention relates to a ball screw support device, and more particularly, to a device for rotatably supporting both ends of a ball screw used in a machine tool.

In general, the ball screw can linearly move the conveyed object by rotational motion. Accordingly, both ends of the ball screw may be rotatably supported by the support device.

According to related technologies, the supporting device may be divided into a fixed-fixing type and a fixed-supporting type. The fixing-fixing type support device may be a method of fixing both ends of the ball screw so as not to move in the axial direction. In the fixed-support type support device, one end of the ball screw is fixed so as not to move in the axial direction, but the other end of the ball screw may be supported so that it can move in the axial direction.

The fixed-fixing type support device can receive a strong load due to the thermal displacement of the ball screw. A strong load can damage the fixed-fixed support device.

In a fixed-support type support device, an axial load may be applied to the fixed-side bearing, causing the ball screw to vibrate.

The present invention provides a ball screw support device having improved durability while preventing the ball screw from shaking.

A ball screw support device according to an aspect of the present invention may include a first bearing unit, a second bearing unit, and a pressing unit. The first bearing unit may rotatably support one end of the ball screw, and fix one end of the ball screw so that one end of the ball screw does not move in an axial direction of the ball screw. The second bearing unit may rotatably support the other end of the ball screw. The pressing unit may selectively press the second bearing unit to fix the other end of the ball screw so that the other end of the ball screw does not move in the axial direction.

In exemplary embodiments, the pressing unit includes a clamping ring coupled to the second bearing unit, and a hydraulic line for applying hydraulic pressure to the clamping ring so that the clamping ring fixes the other end of the ball screw. may include

In example embodiments, the hydraulic line may be connected to an outer circumferential surface of the clamping ring, such that the clamping ring may press the second bearing unit toward the center of the ball screw.

In exemplary embodiments, the clamping ring may include an elastic material to be restored after the hydraulic pressure is removed.

In example embodiments, the pressing unit may further include a spacer interposed between the clamping ring and the second bearing unit to transmit the hydraulic pressure applied to the clamping ring to the second bearing unit. .

In exemplary embodiments, the first bearing unit includes a first angular bearing that rotatably supports one end of the ball screw, and a first bearing that fixes the first angular bearing and fixes one end of the ball screw. Brackets may be included.

In exemplary embodiments, the second bearing unit includes a second angular bearing that rotatably supports the other end of the ball screw, and a second bearing bracket that fixes the second angular bearing and is pressed by the pressing unit. may include

According to the present invention described above, one end of the ball screw is always fixed, but the other end may be selectively fixed by the pressing unit. Accordingly, the support device can be selectively switched between a fixed-support manner and a fixed-fix manner. As a result, the phenomenon in which the ball screw vibrates in the axial direction can be suppressed. In particular, in a machine tool employing a ball screw, the support device may be usefully used for precision machining at low speed.

1 is a cross-sectional view showing a ball screw support device according to an embodiment of the present invention.
FIG. 2 is an enlarged cross-sectional view of a first bearing unit of the support device shown in FIG. 1 ;
FIG. 3 is an enlarged cross-sectional view of a second bearing unit and a pressing unit of the support device shown in FIG. 1 .

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Since the present invention can have various changes and can have various forms, specific embodiments are illustrated in the drawings and described in detail in the text. However, this is not intended to limit the present invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention. In describing each figure, like reference numerals have been used for like elements.

Terms such as first, second, etc. may be used to describe various elements, but the elements should not be limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, a first component may be referred to as a second component, and similarly, a second component may also be referred to as a first component.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or a combination thereof described in the specification exists, but one or more other features It is to be understood that it does not preclude the possibility of the presence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

1 is a cross-sectional view showing a ball screw support device according to an embodiment of the present invention, FIG. 2 is an enlarged cross-sectional view of the first bearing unit of the support device shown in FIG. 1, and FIG. 3 is the support shown in FIG. It is sectional drawing which enlarged and showed the 2nd bearing unit and pressurization unit of an apparatus.

1 to 3 , the ball screw support device according to the present embodiment may include a first bearing unit 120 , a second bearing unit 130 , and a pressing unit 140 .

In this embodiment, the ball screw 110 may be used in a machine tool. The ball screw 110 may be connected to a servo motor of the machine tool. However, the ball screw 110 is not limited to machine tools and may be used in other machine tools.

The first bearing unit 120 may rotatably support one end of the ball screw 110 . One end of the ball screw 110 may be connected to a servo motor. In addition, the first bearing unit 120 may fix one end of the ball screw 110 so as not to move along the axial direction of the ball screw. The second bearing unit 130 may rotatably support the other end of the ball screw 110 . On the other hand, the second bearing unit 130 may support the other end of the ball screw 110 movably in the axial direction. Accordingly, the supporting device of the present embodiment may correspond to a fixed-support type.

The pressing unit 140 may selectively fix the second bearing unit 130 to prevent the second bearing unit 130 from moving the other end of the ball screw 110 in the axial direction. Therefore, while the pressing unit 140 is operating, the supporting device of the present embodiment may correspond to a fixed-fixing manner. That is, depending on whether the pressing unit 140 operates or not, the support device of the present embodiment may be selectively switched between the fixed-support method and the fixed-fix method.

The first bearing unit 120 may include a first angular bearing 122 , a first bearing bracket 124 , and a bearing cap 126 . The first angular bearing 122 may be coupled to an outer peripheral surface of one end of the ball screw 110 to rotatably support one end of the ball screw 110 . The first angular bearing 122 may be fixed to the first bearing bracket 124 . In addition, the first bearing bracket 124 may fix one end of the ball screw 110 to prevent the ball screw 110 from moving in the axial direction. Accordingly, the first bearing unit 120 may have a fixing function that prevents one end of the ball screw 110 from moving in the axial direction.

The second bearing unit 130 may include a second angular bearing 132 , a collar 133 , a lock nut 134 , a bearing housing 136 and a second bearing bracket 138 . can The second angular bearing 132 may be coupled to the outer peripheral surface of the other end of the ball screw 110 to rotatably support the other end of the ball screw 110 . The other end of the ball screw 110 may be fixed to the inner circumferential surface of the second angular bearing 132 by the collar 133 and the lock nut 134 . The bearing housing 136 may accommodate the second angular bearing 132 . The bearing housing 136 may be fixed to the second bearing bracket 138 . Therefore, since the second bearing bracket 138 cannot directly contact the ball screw 110, the second bearing unit 130 has a supporting function that allows the other end of the ball screw 110 to move in the axial direction. can have

As such, since the ball screw 110 is supported in a fixed-support manner by the first bearing unit 120 and the second bearing unit 130 , the ball screw 110 may have weak axial rigidity. Due to this, a phenomenon in which the ball screw 110 vibrates in the axial direction may occur. Alternatively, when the machine tool performs a precision machining operation at a low speed, the axial movement of the ball screw 110 may reduce precision.

In this case, the pressure unit 140 may press the second bearing unit 130 so that the second bearing unit 130 fixes the other end of the ball screw 110 . That is, the second bearing unit 130 may fix the other end of the ball screw 110 to prevent the other end of the ball screw 110 from moving in the axial direction. Accordingly, the pressing unit 140 may convert the second bearing unit 130 from the support type structure to the fixed type structure. The pressing unit 140 having this function may include a clamping ring 142 , a hydraulic block 144 , a spacer 146 , and an end ring 148 .

The clamping ring 142 may be coupled to an outer circumferential surface of the second bearing bracket 138 . That is, the clamping ring 142 may have an inner circumferential surface in close contact with the outer circumferential surface of the second bearing bracket 138 . The clamping ring 142 may include an elastic material.

The hydraulic block 144 may be coupled to the outer circumferential surface of the clamping ring 142 . The hydraulic block 144 may have a hydraulic line 145 to which oil is supplied. The hydraulic line 145 may be connected to the outer circumferential surface of the clamping ring 142 . The hydraulic block 144 and the clamp ring 142 may be supported by an end ring 148 .

Hydraulic pressure applied to the clamping ring 142 through the hydraulic line 145 may strongly compress the clamping ring 142 toward the center of the ball screw 110 . Since the compressed clamping ring 142 strongly compresses the second bearing bracket 138 , the second bearing bracket 138 may fix the second angular bearing 132 . As a result, the second angular bearing 132 fixes the other end of the ball screw 110 , so that the ball screw 110 cannot move in the axial direction.

When the hydraulic pressure supply is stopped, the clamping ring 142 of the elastic material can be returned to its original position. Accordingly, the second angular bearing 132 does not fix the other end of the ball screw 110 along the axial direction, so that the second bearing unit 130 may be converted back to a support structure.

Additionally, a spacer 136 may be interposed between the clamping ring 132 and the second bearing bracket 138 . The spacer 136 may transmit the compressive force of the clamping ring 132 to the second bearing bracket 138 .

As described above, according to the present embodiments, one end of the ball screw is always fixed, but the other end may be selectively fixed by the pressing unit. Accordingly, the support device can be selectively switched between a fixed-support manner and a fixed-fix manner. As a result, the phenomenon in which the ball screw vibrates in the axial direction can be suppressed. In particular, in a machine tool employing a ball screw, the support device may be usefully used for precision machining at low speed.

On the other hand, in the present embodiment, the second bearing unit 130 is switched between the support method and the fixed method with the pressure unit 140 using hydraulic pressure, but other mechanical mechanisms that can apply pressure to the second bearing unit 130 are method can also be used.

As described above, although described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. and may be changed.

110 ; ball screw 120 ; first bearing unit
122; first angular bearing 124 ; 1st bearing bracket
126 ; bearing cap 130 ; 2nd bearing unit
132; second angular bearing 133; color
134; lock nut 136 ; bearing housing
138 ; second bearing bracket 140 ; pressurization unit
142; clamping ring 144 ; hydraulic block
145; hydraulic line 146 ; spacer
148 ; end ring

Claims (6)

a first bearing unit rotatably supporting one end of the ball screw and fixing one end of the ball screw so that one end of the ball screw does not move along an axial direction of the ball screw;
a second bearing unit rotatably supporting the other end of the ball screw and movably supporting the other end of the ball screw in the axial direction; and
and a pressing unit for selectively pressing the second bearing unit to fix the other end of the ball screw so that the other end of the ball screw does not move along the axial direction,
The second bearing unit is
a second angular bearing to which the other end of the ball screw is fixed;
a bearing housing accommodating the second angular bearing; and
and a second bearing bracket to which the bearing housing is fixed and pressed by the pressing unit;
A ball screw support device in which direct contact between the second bearing bracket and the ball screw is prevented so that the other end of the ball screw is movable in the axial direction by the second bearing unit. According to claim 1, wherein the pressure unit is
a clamping ring coupled to the second bearing unit; and
and a hydraulic line for applying hydraulic pressure to the clamping ring so that the clamping ring fixes the other end of the ball screw. The ball screw support device according to claim 2, wherein the hydraulic line is connected to an outer circumferential surface of the clamping ring so that the clamping ring presses the second bearing unit toward the center of the ball screw. 3. The ball screw support device of claim 2, wherein the clamping ring comprises a resilient material to be restored after the hydraulic pressure is removed. The ball screw support device according to claim 2, wherein the pressing unit further comprises a spacer interposed between the clamping ring and the second bearing unit to transmit the hydraulic pressure applied to the clamping ring to the second bearing unit. .

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