JP2013040642A - Lubricant supply device, and rolling element screw device with the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling element screw device that enables extended product lifetime of a seal member fixed to an end of a lubricant supply device.SOLUTION: The lubricant supply device is assembled to the rolling element screw device comprising a screw shaft whose outer peripheral surface is formed with a spiral rolling element rolling groove, and a movement member having a through-hole in which the screw shaft penetrates, engaging with the screw shaft via a plurality of rolling elements, and having an inner peripheral surface formed with a spiral load rolling element rolling groove, and supplies lubricant stored in an occlusion body to the screw shaft. Further, the lubricant supply device includes a plurality of applicators having different lengths in a radius direction of the screw shaft.

Description

  The present invention relates to a lubricant supply device that applies a lubricant to a screw shaft as the moving member moves relative to the screw shaft, and a rolling element screw device including the lubricant supply device.

  Conventionally, a screw shaft having a spiral rolling element rolling groove formed on the outer peripheral surface and a through-hole through which the screw shaft penetrates in the axial direction are screwed into the screw shaft via a plurality of rolling elements. A rolling element screw device provided with a moving member formed with a spiral loaded rolling element rolling groove opposite to the rolling element rolling groove of the screw shaft on the inner peripheral surface. A rolling element screw device incorporating a lubricant supply device that supplies a lubricant is known.

  As a lubricant supply device for supplying a lubricant to such a rolling element screw device, a lubricant supply device described in Patent Document 1 and a rolling element screw device to which this lubricant supply device is attached are known.

  The rolling element screw device described in Patent Document 1 is attached to a nut member that engages with a screw shaft having two or more ridges via a rolling element, and the relative rotation and rotation of the nut member with respect to the screw shaft. A lubricating oil supply device that supplies lubricating oil to the screw shaft as it moves, and has a tongue piece that contacts the rolling element rolling surface of the screw shaft, and applies the lubricating oil to the screw shaft. An application body, a casing forming a lubricating oil storage chamber for supplying lubricating oil to the application body, and a control means for controlling the amount of lubricating oil supplied from the lubricating oil storage chamber to the application body. The lubricating oil storage chamber is formed in a cylindrical shape so as to be loosely fitted to the screw shaft, and is divided into a plurality of compartments having the number of strips or more in the circumferential direction, and the application body is provided in each of the plurality of compartments. Correspondingly, a plurality of tongues are provided on each of the plurality of application bodies. There has been formed one by one. Note that a contact-type seal member that comes into contact with the outer peripheral surface of the screw shaft is assembled in the lubricant supply device.

  According to such a structure, lubricating oil is apply | coated to the rolling-element rolling surface of a screw shaft from the tongue piece part of an application body, when a screw shaft rotates with respect to a moving member.

Japanese Patent No. 3454502

  However, in the conventional rolling element screw device assembled with this lubricant supply device, the lubricant applied to the rolling element rolling groove is prevented from leaking outside the moving member in the axial direction of the lubricant supply device. When an annular seal member that contacts the entire circumference of the screw shaft is assembled at the end, the coated body applies lubricant to only the rolling element rolling groove of the screw shaft, while it contacts the outer peripheral surface of the screw shaft. Since the lubricating oil is not sufficiently applied to the portion to be applied, the seal member is worn out at an early stage, which causes a problem of affecting the life of the rolling element screw device. This is because the seal member needs to be in sliding contact with the outer peripheral surface of the screw shaft with a predetermined contact pressure in order to secure the tightening allowance of the seal.

  The present invention has been made in order to solve the above-mentioned problems. A lubricant supply device capable of preventing premature wear of the seal member and extending the product life of the rolling element screw device, and a rolling device using the same. An object is to provide a moving body screw device.

  The lubricant supply device according to the present invention includes a screw shaft having a spiral rolling element rolling groove formed on an outer peripheral surface, and a through hole through which the screw shaft passes, and the screw is interposed through a plurality of rolling elements. A screw member that is screwed into a shaft and has a moving member formed with a spiral load rolling element rolling groove facing the rolling element rolling groove on an inner peripheral surface thereof, and is assembled to a rolling element screw device, In the lubricant supply device for supplying the lubricant stored in the occlusion body, the lubricant supply device includes a plurality of application bodies having different lengths in the radial direction of the screw shaft.

  According to the present invention, since the lubricant supply device includes a plurality of application bodies having different lengths in the radial direction of the screw shaft, the lubricant is applied to both the rolling element rolling groove and the outer peripheral surface of the screw shaft. It is possible to prevent wear of the seal member in sliding contact, and to extend the life of the rolling element screw device.

The perspective view which shows the rolling element screw apparatus which concerns on embodiment of this invention. The exploded view of the rolling element screw device concerning the embodiment of the present invention. Sectional drawing for demonstrating the structure of the lubricant supply apparatus which concerns on embodiment of this invention. AA sectional drawing in FIG. The exploded view of the lubricant supply device concerning the embodiment of the present invention. Sectional drawing for demonstrating an effect | action of the rolling element screw apparatus which concerns on embodiment of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a lubricant supply device according to the present invention and a rolling element screw device incorporating the lubricant supply device will be described with reference to the drawings. The following embodiments do not limit the invention according to each claim, and all combinations of features described in the embodiments are not necessarily essential to the solution means of the invention. .

  FIG. 1 is a perspective view showing a rolling element screw device according to an embodiment of the present invention, FIG. 2 is an exploded view of the rolling element screw device according to an embodiment of the present invention, and FIG. FIG. 4 is a cross-sectional view for explaining a configuration of a lubricant supply device according to the embodiment, FIG. 4 is a cross-sectional view taken along line AA in FIG. 3, and FIG. 5 is a lubricant supply device according to the embodiment of the present invention. FIG. 6 is a cross-sectional view for explaining the operation of the rolling element screw device according to the embodiment of the present invention.

  As shown in FIGS. 1 and 2, the rolling element screw device 1 according to the present embodiment includes a screw shaft 10 in which a spiral rolling element rolling groove 11 is formed with a predetermined lead on an outer peripheral surface 12, and a plurality of screw shafts 10. There is provided a moving member 20 having a spiral loaded rolling element rolling groove 22 formed on the inner peripheral surface thereof, which is screwed onto the screw shaft 10 via the rolling element 30 and faces the rolling element rolling groove 11.

  The rolling surface of the rolling element rolling groove 11 formed on the screw shaft 10 can receive a load from a spherical rolling element 30 arranged in a load rolling element rolling path described later. Further, the rolling element rolling groove 11 is subjected to surface processing with an accuracy such that smooth rolling of the rolling element 30 can be realized. The rolling surface shape may be a Gothic arch shape or a circular arc shape.

  The moving member 20 has a nut main body 20a formed in a substantially cylindrical shape and a flange portion 23 for attaching a mating member formed at one end of the nut main body 20a. The moving member 20 is provided with a through hole 20b for conducting the screw shaft 10 in the axial direction. A load rolling element rolling groove 22 facing the rolling element rolling groove 11 is formed on the inner peripheral surface of the through hole 20b. Is formed. Further, similarly to the rolling element rolling groove 11, the load rolling element rolling groove 22 is subjected to surface processing with an accuracy that enables smooth rolling of the rolling element 30. The loaded rolling element rolling groove 22 and the rolling element rolling groove 11 form a loaded rolling element rolling path, and a plurality of rolling elements 30 are arranged in the rolling element rolling path. The rolling surface shape of the loaded rolling element rolling groove 22 may be a Gothic arch shape or a circular arc shape.

  Furthermore, the moving member 20 is formed with a rolling element return passage 24 extending in the axial direction of the rolling element screw device, and the direction change for connecting the above-described load rolling element rolling path and the rolling element return path to both ends in the axial direction. An end cap 25 in which a path is formed is attached. Thereby, infinite circulation of the rolling elements 30 is realized. Furthermore, the system for realizing the infinite circulation of the rolling elements 30 is not limited to this, and a known infinite circulation system can be employed. Further, the lubricant supply device 40 and the seal member 50 are assembled to the end of the moving member 20 in the axial direction by fastening means such as bolts.

  The seal member 50 is a lip-shaped member formed in an annular shape with rubber or the like, and is in contact with the outer peripheral surface 12 of the screw shaft 10 and the rolling element rolling groove 11 with a predetermined contact pressure. For this reason, the inner peripheral surface of the seal member 50 is not formed in a perfect circle, and the position in contact with the rolling element rolling groove 11 is changed so as to be substantially the same shape as the radial cross-sectional shape of the screw shaft 10. It has a shape that bulges according to the shape of the moving body rolling groove 11.

  The lubricant supply device 40 is attached to the outer end face of the end cap 25 attached to the axial end of the moving member 20. Further, a seal member 50 is attached in a direction opposite to the end cap 25 with the lubricant supply device 40 interposed therebetween. As shown in FIG. 3, the lubricant supply device 40 includes a plurality of application bodies 41 and 42 having different lengths in the radial direction of the screw shaft 10, and specifically, slides on the outer peripheral surface 12 of the screw shaft 10. A first application body 41 for applying a lubricant in contact therewith, a second application body 42 for applying a lubricant in sliding contact with the rolling element rolling grooves 11, an occlusion body 43 for storing the lubricant, A first application body 41, a second application body 42, and a frame body 44 for storing the occlusion body 43.

  The first application body 41 and the second application body 42 are assembled to the frame body 44 so that the main body portions 41 a and 42 a protrude from the inner peripheral side of the frame body 44 toward the screw shaft 10 side. Further, the first application body 41 is in sliding contact with the outer peripheral surface 12 of the screw shaft 10, and the second application body 42 is in contact with the first application body 41 and the first application body so as to be in sliding contact with the rolling element rolling groove 11. The two application bodies 42 are formed with different lengths along the protruding direction. Specifically, the length along the protruding direction is such that the first application body 41 is shorter than the second application body 42.

  As shown in FIG. 4, the first application body 41 and the second application body 42 are arranged at substantially equal intervals along the circumferential direction of the frame body 44, and the outer peripheral surface 12 of the screw shaft 10. And the length along the protrusion direction is adjusted so that it can slidably contact with the rolling element rolling groove 11 with an appropriate fastening margin.

  The frame body 44 is formed in an annular shape that is substantially the same as the cross-sectional shape of the nut main body 20a of the moving member 20, and is formed in a bottomed shape in which a storage chamber 44a for storing the storage body 43 is formed. . The storage chamber 44 a is formed continuously in the circumferential direction of the frame body 44. Furthermore, a slit 47 and a through hole 45 are formed on the inner peripheral surface side, which is a surface corresponding to the screw shaft 10. Since the through hole 45 is formed on the inner peripheral surface side of the frame body 44 in this way, in addition to preventing dust from entering the lubricant supply device 40 through the through hole 45, the lubricant supply device 40. Since the lubricant can be applied to the screw shaft 10 even when the lubricant leaks from the lubricant, the lubricant is not wasted.

  The occlusion body 43 is made of felt which is a material that absorbs and stores a lubricant, and for example, rayon + wool felt having a porosity of about 80% is used. As shown in FIG. 5, the occlusion body 43 is formed in a substantially annular shape having substantially the same shape as the storage chamber 44 a formed in the frame body 44, and is integrally formed continuously in the circumferential direction.

  The first application body 41 and the second application body 42 are in contact with the outer peripheral surface 12 of the screw shaft 10 and the rolling element rolling grooves 11 and the occlusion body 43 in contact with the main body portions 41a and 42a. It has communication parts 41b and 42b supplied to parts 41a and 42a. The connecting portions 41b and 42b are formed at the ends of the first application body 41 and the second application body 42 so as to extend in a direction intersecting with the extending direction of the main body portions 41a and 42a. Thus, the first application body 41 and the second application body 42 are formed in a substantially T-shaped cross section, and the main body portions 41 a and 42 a are sandwiched between the slits formed on the inner peripheral surface side of the frame body 44. Since they are assembled, the connecting portions 41 b and 42 b also have a function of preventing the first application body 41 and the second application body 42 from falling in the direction of the screw shaft 10.

  The first application body 41 and the second application body 42 are also formed of felt, but the felt used for the first application body 41 and the second application body 42 is attached to the occlusion body 43. The porosity is lower than the felt used. Specifically, wool felt having a porosity of about 50% is used for the felts of the first application body 41 and the second application body 42. In addition, the felt used for the 1st application body 41 and the 2nd application body 42 is not restricted to this, The felt of the porosity smaller than the porosity used for the occlusion body 43 can be used suitably. According to such a configuration, since the first application body 41 and the second application body 42 are in contact with the occlusion body 43, the lubricant stored in the occlusion body 43 by capillary action is the first application body. 41 and the second application body 42.

  Further, any lubricant may be used as the lubricant as long as smooth rolling of the rolling elements can be realized. For example, lubricating oil such as sliding surface oil and turbine oil may be used. Grease such as lithium grease and urea grease may be used.

  As shown in FIG. 5, the lubricant supply device 40 configured as described above has a main body portion of the first application body 41 and the second application body 42 in the slit 47 formed on the inner peripheral surface side of the frame body 44. 41a and 42a are assembled | attached, and also the occlusion body 43 is assembled | attached to the storage chamber 44a, Then, the opening part is obstruct | occluded with the cover body 46, and it forms. The lid body 46 is fastened and fixed to the frame body 44 by bolts 46a.

  Further, since the through hole 45 is formed on the inner peripheral surface side of the frame body 44 so as to face the outer peripheral surface 12 of the screw shaft 10, when the lubricant is supplied from the occlusion body 43, the through hole is provided. By introducing the outside air from 45, the pressure inside the storage chamber 44a becomes equal to the outside, and the lubricant moves from the occlusion body 43 to the first application body 41 and the second application body 42 due to the pressure difference. Since there is no hindrance, the supply of lubricant can be promoted smoothly.

  As shown in FIG. 6, the lubricant supply device 40 is in contact with the rolling element rolling groove 11 and the outer peripheral surface 12 of the screw shaft 10 as the moving member 20 moves with respect to the screw shaft 10. The lubricant is applied to the rolling element rolling groove 11 and the outer peripheral surface 12 of the screw shaft 10 by the application body 41 and the second application body 42. When the lubricant applied by the first application body 41 and the second application body 42 decreases with the application of the lubricant, the capillary phenomenon occurs through the connecting portions 41b and 42b that contact the storage body 43. Thus, the lubricant is supplied from the occlusion body 43 to the first application body 41 and the second application body 42.

  In addition, since the 1st application body 41 and the 2nd application body 42 are formed in the circumferential direction of the screw shaft 10 at equal intervals, the outer peripheral surface 12 of the screw shaft 10 and the rolling-element rolling groove 11 are provided. The lubricant can be applied uniformly along the circumferential direction.

  As described above, in the rolling element screw device 1 according to the present embodiment, the lubricant supply device 40 is in slidable contact with the first application body 41 that is in sliding contact with the outer peripheral surface 12 of the screw shaft 10 and the rolling element rolling groove 11. Since the rolling body 30 is smoothly rolled by applying a lubricant to the rolling element rolling groove 11, the lubricant is applied to the outer peripheral surface 12 of the screw shaft 10. By doing so, the friction of the seal member 50 in contact with the outer peripheral surface 12 of the screw shaft 10 can be reduced, the wear of the seal member 50 can be suppressed, and the product life of the seal member 50 can be extended.

  Further, since the storage chamber 44a formed in the frame body 44 and the storage body 43 stored in the storage chamber 44a are formed in series in the circumferential direction, the storage body maintains the outer dimensions of the lubricant supply device 40. It is possible to increase the amount of lubricant that can be stored in 43, and to extend the maintenance cycle such as replenishment of the lubricant.

  The present invention is not limited to the above embodiment, and various modifications can be made without departing from the scope of the present invention. For example, in this embodiment, a case where a spherical ball is applied to the rolling element 30 has been described. However, a cylindrical roller may be used as the rolling element in addition to the ball. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 Rolling body screw apparatus, 10 Screw shaft, 11 Rolling body rolling groove, 12 Outer peripheral surface, 20 Moving member, 20b Through-hole, 22 Load rolling body rolling groove, 30 Rolling body, 40 Lubricant supply apparatus, 41 1st Application body, 42 second application body, 43 occlusion body, 44 frame body, 45 through-hole, 50 seal member.

Claims (5)

A screw shaft having a spiral rolling element rolling groove formed on the outer peripheral surface;
A spiral loaded rolling element rolling groove having a through-hole through which the screw shaft passes, screwed into the screw shaft via a plurality of rolling elements, and opposed to the rolling element rolling groove on the inner peripheral surface A moving member formed with
In a lubricant supply device assembled to a rolling element screw device comprising: a lubricant stored in an occlusion body on the screw shaft;
The lubricant supply device includes a plurality of application bodies having different lengths in the radial direction of the screw shaft. The lubricant supply device according to claim 1,
The occlusion body is integrally formed continuously in the circumferential direction,
The lubricant supply device, wherein the application body is in contact with the occlusion body. The lubricant supply device according to claim 1 or 2,
The application body includes a first application body that is in sliding contact with the outer peripheral surface of the screw shaft, and a second application body that is in sliding contact with the rolling element rolling groove. In the lubricant supply device according to claim 3,
The lubricant supply device, wherein the frame body including the first application body, the second application body, and the occlusion body has a through hole.   A rolling element screw device comprising the lubricant supply device according to any one of claims 1 to 4.

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