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KR-20260064010-A - BALL SCREW APPARATUS

KR20260064010AKR 20260064010 AKR20260064010 AKR 20260064010AKR-20260064010-A

Abstract

The ball screw device according to the present invention comprises a screw shaft having a spiral groove formed on its outer surface, a ball nut through which the screw shaft passes and which moves axially when the screw shaft rotates, and a sensor installed on the ball nut, and has the advantage of being able to determine overheating or operational abnormalities using the signal of the sensor.

Inventors

  • 정효진
  • 박현섭
  • 박태성
  • 김동원
  • 원영석
  • 임은정

Assignees

  • 주식회사 에스비씨리니어

Dates

Publication Date
20260507
Application Date
20241031

Claims (14)

  1. Screw shaft with a spiral groove formed on the outer surface; A ball nut through which the screw shaft passes and which moves axially when the screw shaft rotates; and A ball screw device comprising a sensor installed on the ball nut.
  2. In claim 1, The ball nut above is, The first ball nut and, A second ball nut spaced axially from the first ball nut, and It includes a sensor ring disposed between the first ball nut and the second ball nut, and The above sensor is a ball screw device installed in the above sensoring.
  3. In claim 1, A flat portion is formed on the outer surface of the above-mentioned sensoring, and The sensor above is a ball screw device installed on the flat surface.
  4. In claim 3, An outwardly convex curved surface is further formed on the outer surface of the sensoring above, and The above planar portion and the above curved portion are formed alternately in the circumferential direction, the planar portion is formed of a plurality of planar portions, and the above curved portion is formed of a plurality of curved portions. The above sensor is a ball screw device comprising a plurality of sensors each disposed in the plurality of planar portions.
  5. In claim 3, A ball screw device having axial holes formed on both sides of the axial direction of the portion where the flat portion is formed, which are axially interconnected.
  6. In claim 5, The above-mentioned axial hole is a ball screw device that penetrates a portion spaced radially inward from the sensor.
  7. In claim 3, The above sensoring is a ball screw device in which axial grooves are formed on each side in the axial direction of the portion in which the planar portion is formed.
  8. In claim 7, The above-mentioned axial groove is a ball screw device extending to a portion spaced radially inward from the sensor.
  9. In claim 8, A ball screw device in which the ratio of the sum of the depths of the axial grooves formed on each side in the axial direction of the portion in which the above-mentioned planar portion is formed to the axial length of the sensor ring is 0.8 or less.
  10. In claim 7, A ball screw device in which the axial grooves formed on each side of the axial direction of the portion in which the planar portion is formed are formed as a plurality of axial grooves spaced apart from each other in a direction parallel to the planar portion.
  11. In claim 3, The sensor installed on the above-mentioned planar portion is a ball screw device equipped with a plurality of sensors.
  12. In claim 3, The above sensoring includes a ball screw device in which a radial groove is formed on the curved surface.
  13. In claim 12, A ball screw device in which the radial inner surface of the above radial groove is formed in a concave round shape.
  14. In claim 12, A ball screw device in which the ratio of the depth of the radial groove to the thickness of the portion in which the curved surface is formed during the sensing is 0.8 or less.

Description

Ball Screw Apparatus The present invention relates to a ball screw device, and more specifically, to a ball screw device comprising a screw shaft and a ball nut, wherein the ball nut moves linearly when the screw shaft rotates. Generally, a ball screw is configured to include a screw shaft having a spiral groove formed on its outer surface and a ball nut through which the screw shaft passes, and when the screw shaft rotates, the ball nut moves in a straight line as a plurality of balls roll along the spiral groove. A transfer target to be moved linearly is coupled to the ball nut, and when the ball nut moves linearly, the transfer target moves linearly together with the ball nut, thereby moving linearly to a specific position. Korean Patent Publication No. 10-2023-0060180 (May 4, 2023) (hereinafter referred to as the “prior art”) discloses a “ball screw.” The above prior art includes a screw shaft having a spiral outer groove formed on its outer surface; a ball nut having a spiral inner groove formed on its inner surface corresponding to the outer groove of the screw shaft, which accommodates the screw shaft; a plurality of balls that slide along a ball path enclosed by the outer groove and the inner groove so as to move relative to the screw shaft and the ball nut; a return piece assembled on one side of the ball nut and guiding the balls to recirculate along the ball path; and a rivet that passes through the return piece and one side of the ball nut to secure the return piece to one side of the ball nut. In a ball screw device including a plurality of balls as in the above-described prior art, a large amount of heat is generated due to friction during the circulation of the plurality of balls. In this case, the movement of the ball nut must be stopped until the generated heat cools down in order to prevent damage to the ball screw. However, the aforementioned conventional technology had a problem in that it was difficult to determine whether the heat was generated because a means for detecting the heat was not installed. FIG. 1 is a perspective view showing a ball screw device according to a first embodiment of the present invention, FIG. 2 is a rear perspective view of FIG. 1 viewed from the opposite side, FIG. 3 is an exploded perspective view of FIG. 1, FIG. 4 is a perspective view showing the sensing illustrated in FIG. 3, FIG. 5 is a bottom perspective view of FIG. 4 viewed from the opposite side. Fig. 6 is a cutaway perspective view of Fig. 4, FIG. 7 is a perspective view showing a second embodiment of the sensing, FIG. 8 is a rear perspective view of FIG. 7, FIG. 9 is a cross-sectional view showing a cutaway perspective view of FIG. 7 and a part thereof, FIG. 10 is a perspective view showing a third embodiment of the sensing, FIG. 11 is a rear perspective view of FIG. 10, FIG. 12 is a cutaway perspective view of FIG. 10, FIG. 13 is a perspective view showing a fourth embodiment of the sensing, FIG. 14 is a rear perspective view of FIG. 13, FIG. 15 is a cross-sectional view showing the cutaway perspective view of FIG. 13 and a part thereof. Hereinafter, a ball screw device according to embodiments of the present invention will be described with reference to the drawings. It should be noted that when assigning reference numerals to the components of each drawing, the same components are assigned the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, in describing the embodiments of the present invention, if it is determined that a detailed description of related known components or functions would hinder understanding of the embodiments of the present invention, such detailed description is omitted. In describing the components of the embodiments of the present invention, terms such as first, second, A, B, (a), (b), etc., may be used. These terms are intended merely to distinguish the components from other components, and the essence, order, or sequence of the components is not limited by such terms. Furthermore, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as generally understood by those skilled in the art to which the present invention pertains. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in this application. FIG. 1 is a perspective view showing a ball screw device according to a first embodiment of the present invention, FIG. 2 is a rear perspective view of FIG. 1 viewed from the opposite side, and FIG. 3 is an exploded perspective view of FIG. 1. In the following description, the axial direction may be the same direction as the longitudinal direction of the screw shaft (100), and the radial direction may be the same direction as the radial direction of the screw sh