JP4732263B2 - Ball screw lubrication seal device - Google Patents

Description

  The present invention relates to a ball screw lubrication seal device, and in particular, in a ball screw device, lubrication between a thread groove of a screw shaft, which is a screw rolling portion, and a ball, and lubrication between a thread groove of a ball screw nut and a ball for a long time. The present invention relates to a lubricating seal device that can be used without replenishing.

  Conventionally, this type of ball screw lubrication seal device has been known to have a structure as described in Patent Document 1, for example. In this ball screw lubrication seal device, the thin plate seal plates having holes corresponding to the cross-sectional shape perpendicular to the axis of the screw groove of the screw shaft are overlapped in the circumferential direction, and held by the frame-shaped ring to end the ball screw nut. Although it was attached to the part, it had only a function as a sealing device, that is, a sealing device, and could not be used without replenishing oil for a long time.

Also, lubrication mechanisms such as those disclosed in Patent Document 2 and Patent Document 3 are known.
The former is configured such that a rubber or synthetic resin ring containing a lubricant is attached to an end of a ball screw nut with a pressing member, and a preload is applied in the circumferential direction of the synthetic resin ring by a protruding portion of the pressing member. That is, the contact state is maintained for a long time by applying a pressing force to the ball, which is a rolling element that always contacts the lubricant supply member. Therefore, the lubrication mechanism becomes complicated.

Moreover, since the latter is mounted on a slide member such as a ball screw nut as in the former, the member to which the lubricating oil is applied is composed of a wool-mixed polyester felt or a sintered resin, as described in the specification, A large amount of lubricant can be absorbed and retained. In such a device, even if a large amount of oil can be retained, the lubricating oil for supplying oil to this member is always used when the oil is adhered to the rolling elements, that is, the balls. An occlusion body (tank function) is added. In addition, the contact portion of the member that applies the lubricating oil that retains the oil with the ball loses its elasticity with time and causes plastic deformation, which deteriorates the contact state with the rolling ball and reduces the lubricating action. Resulting in. Also, since the normal felt material has a large gap, the absorbed oil is also likely to flow out. Therefore, as described in the specification, a device such as a flow control valve is required between the occlusion body and the application body. It becomes.

In view of such a situation, the present inventor has proposed the structures shown in Patent Document 4 and Patent Document 5. These inventions have the advantages of simplifying the lubrication structure and enabling more stable lubricant supply for a long period of time by holding more lubricant.
Japanese Utility Model Publication No. 5-43310 Japanese Patent Laid-Open No. 10-2395 Japanese Patent No. 3288961 JP 2005-155701 A JP-A-2005-155702

However, the structures shown in Patent Document 4 and Patent Document 5 cannot be easily aligned when attached to a ball screw nut or a screw shaft. Further, since the lubrication seal device is attached to the end face of the ball screw nut by adhesion, replacement or the like cannot be easily performed.
Therefore, it has been expected to realize a structure that can be reliably aligned with the ball screw nut and can be easily assembled even by an inexperienced person.

  The present invention has been made to solve such a conventional problem, and its purpose is that phase alignment of the thread groove of the screw shaft and the seal inner surface is easy, and the mounting to the ball screw nut is reliable. It is an object of the present invention to provide a ball screw lubricating seal device that is easy.

A lubrication and seal device for a ball screw according to the present invention includes a screw shaft, a plurality of screw holes at both ends, a ball screw nut that is screwed onto the outer periphery of the screw shaft, and a plurality of small holes that penetrate the peripheral portion. An annular outer frame body that abuts on both end faces of the ball screw nut, a plurality of small holes that penetrate the peripheral edge portion, an annular inner frame body that fits within the annular outer frame body, and a peripheral edge portion. Provided with a plurality of small holes, impregnated and retained with a lubricant, the seal ring is internally held in the annular inner frame with an inner diameter corresponding to the cross-sectional shape perpendicular to the axis of the screw shaft, and the ring having the seal ring held internally A plurality of small holes provided in each peripheral portion of the annular inner frame, the seal ring, and the annular outer frame, the annular outer frame being fitted into the inner frame and abutting against both end faces of the ball screw nut, respectively. Through said Bo And a bolt for fixing by screwing into the screw holes in the end faces of the screw nut, said annular outer frame, a plurality of small holes provided in the annular frame and the sealing ring, respectively diametrically opposed And is formed at an asymmetrical position of the end surface of the ball screw nut by shifting the phase of one hole position of each of the small holes. The bolt head is set to a size that can be inserted, and the seal ring is positioned by the bolt head .

1. Since the lubrication seal device is attached to the ball screw nut with a bolt, it is easy to install and easy to maintain.
2. By fixing the position of the seal ring at the head of the bolt and fitting it, the lubricant can be held in the screw, and a longer maintenance-free operation can be achieved.

Hereinafter, the present invention will be described based on embodiments shown in the drawings.
FIG. 1 shows a lubricating seal device for a ball screw according to an embodiment of the present invention.
The ball screw lubrication seal device 4 according to the present embodiment is attached to both end faces 2c, 2c of the ball screw nut 2 and a large number of balls 3 are interposed between the screw shaft 1 inserted into the ball screw nut 2. And a device for making a relative spiral movement of the screw shaft 1 is used for lubricating the groove portion and the outer shape portion.

  As shown in FIGS. 1 to 3, the ball screw lubrication seal device 4 according to this embodiment is provided with a screw shaft 1 and screw holes 2a and 2b at both ends 2c and 2c. The ball screw nut 2 to be joined, the outer diameter 41d is a size substantially matching the ball screw nut 2, the cross-sectional shape is substantially U-shaped, and the outer diameter 42d is the inner diameter 41c of the annular outer frame body 41. An annular inner frame body 42 formed in a U-shape in the opposite direction to the annular outer frame body 41 with a fitting size, and disposed between the annular outer frame body 41 and the annular inner frame body 42 and having an outer diameter 43 f is inserted into the inner diameter 42 c of the annular inner frame body 42, and the seal ring 43 and the bolt 5 are formed by forming the inner diameter 43 e into a shape corresponding to the cross-sectional shape perpendicular to the axis of the screw shaft 1. As shown in Patent Documents 4 and 5 previously proposed by the present applicant, the seal ring 43 is a fiber body in which resin fibers and a rubber elastic body are three-dimensionally fused, and is internally impregnated with lubricating oil. .

  The ball screw lubrication seal device 4 according to the present embodiment is attached to both end faces 2 c and 2 c of the ball screw nut 2 by bolts 5. For this purpose, two small holes 41a, 41b, 42a, 42b, 43a, 43b are formed in the annular outer frame body 41, the annular inner frame body 42, and the seal ring 43, as shown in FIGS. It is. Then, as shown in FIG. 2, the phase is slightly shifted from one hole position (α = 10 ° in the figure). Further, as shown in FIG. 3, screw holes 2 a and 2 b are formed at the same phase position on both end faces 2 c and 2 c of the ball screw nut 2. The small holes 42a, 42b, 43a, 43b in the annular inner frame 42 and the seal ring 43 are formed slightly larger than the diameter of the head 5a of the bolt 5. On the other hand, the small holes 41 a and 41 b of the annular outer frame body 41 are formed to have a size slightly larger than the diameter of the screw portion 5 b of the bolt 5.

Next, assembly of the lubricating seal device 4 according to this embodiment will be described.
When assembling, first, they are combined in the order as shown in FIG. 4, and the outer portion of the seal ring 43 is bonded and fixed to the inner diameter of the annular inner frame body 42 after matching the positions of the small holes. As shown in FIG. 6, the small holes 41a and 41b of the annular outer frame body 41 are aligned with the positions of the screw holes 2a and 2b of the ball screw nut 2, as shown in FIG. Bolts 5 are inserted from the small holes 42a and 42b on the outer side of the inner frame body 42, and are screwed and attached by a spanner (not shown). By attaching in this way, the lubricating seal device 4 is integrally fixed to both end faces 2c, 2c of the ball screw nut 2 as shown in FIGS. At this time, a step 2d is formed on both end faces 2c, 2c of the ball screw nut 2, and an inner diameter 41c of the annular outer frame body 41 is fitted as shown in FIG.

In FIG. 4, the seal ring 43 further has two small holes 43c and 43d. The small holes 43c and 43d are holes through which the bolts 5 are inserted at positions shifted so as to be fitted to the leads of the screw shaft 1 when a plurality of seal rings 43 are mounted in a stacked manner.
In FIG. 3, with the annular outer frame body 41, the annular inner frame body 42 and the seal ring 43 assembled, there is a space between the inner diameter 42c of the annular inner frame body 42 and the seal ring 43. By enclosing the grease, it acts on the screw shaft 1 side together with the lubricating oil impregnated in the seal ring 43, so long-term oil supply is unnecessary and maintenance-free can be achieved.

  As described above, the positions of the small holes 41a, 41b, 42a, 42b, 43a, 43b and the screw holes 2a, 2b of the bolt 5 for attaching the lubricating seal device 4 to the both end faces 2c, 2c of the ball screw nut 2 are slightly shifted. It is formed. For example, if it is formed at a symmetrical position of 180 °, the set position of the inner diameter 43e of the seal ring 43 and the screw shaft 1 may be changed during assembly, so that such erroneous assembly can be prevented. it can.

  As clearly shown in FIG. 3, the seal ring 43 adheres the positions of the small holes 43 a and 43 b to the small holes 42 a and 42 b of the annular inner frame body 42 and adheres the outer portion 43 f to the inner diameter 42 c of the annular inner frame body 42. Fix it. Since a part of the head 5a of the bolt 5 is fitted in the small holes 43a and 43b of the seal ring 43, alignment can be performed by inserting the bolt 5, and the position of the seal ring 43 with respect to the ball screw nut 2 is set to a predetermined position. In this state, the bonding operation can be easily performed, the sealing performance can be stably maintained, and the sealed grease can be prevented from flowing out.

In the present embodiment, the annular outer frame body 41 and the annular inner frame body 42 may be bonded and fixed after being assembled as illustrated. By preparing such a lubricating seal device 4 as a unit, maintenance can be facilitated.
In the above embodiment, the step 2d is formed on both end faces 2c, 2c of the ball screw nut 2 and fixed in the radial direction of the annular outer frame 41. Is possible.

It is a fragmentary sectional view of the lubrication seal device of the ball screw concerning one embodiment of the present invention. It is AA sectional drawing of FIG. FIG. 2 is an enlarged cross-sectional view taken along arrow B in FIG. 1. FIG. 2 is an exploded perspective view of an annular outer frame body 41, a seal ring 43, and an annular inner frame body 42 of FIG. FIG. 2 is an assembled perspective view of the annular outer frame body 41, the seal ring 43, and the annular inner frame body 42 of FIG. It is a disassembled perspective view which shows the attachment state of the lubricous seal apparatus of the ball screw which concerns on one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Screw shaft 2 Ball screw nut 2a, 2b Screw hole 2c End surface 3 of ball screw nut 2 Ball 4 Lubrication seal device 41 Annular outer frame 41a, 41b, 42a, 42b, 43a, 43b Small hole 42 Annular inner frame 43 Seal ring 5 volts

Claims (3)

A screw shaft;
A ball screw nut provided with a plurality of screw holes at both ends and screwed onto the outer periphery of the screw shaft;
A plurality of small holes penetrating the peripheral edge, and annular outer frame bodies that respectively contact the both end faces of the ball screw nut;
A plurality of small holes penetrating the periphery, and an annular inner frame that fits within the annular outer frame;
A seal ring provided with a plurality of small holes penetrating the peripheral edge, impregnated and held with a lubricant, and internally held in the annular inner frame as a shape corresponding to the cross-sectional shape perpendicular to the axis of the screw shaft;
The annular outer frame body fitted into the annular inner frame body holding the seal ring therein and abutting against both end faces of the ball screw nut is connected to the annular inner frame body, the seal ring and the annular outer frame body. A bolt that is fixed by being screwed into the screw holes on both end faces of the ball screw nut through a plurality of small holes provided in each peripheral portion ,
A plurality of small holes provided in the annular outer frame body, the annular inner frame body and the seal ring are provided to face each other in the diameter direction, and by shifting the phase of one hole position of each of the small holes, Formed at the asymmetrical position of the end face of the ball screw nut,
The plurality of small holes of the annular inner frame and the seal ring are set to a size that allows the head of the bolt to be inserted,
A ball screw lubricated seal device , wherein the seal ring is positioned by a head of the bolt . When the plurality of the seal rings are stacked one on top of the other, the bolts can be inserted at positions where the hole positions are shifted in accordance with the leads of the screw shafts. has a plurality of small holes which form a, by shifting the phase of one of the hole position of the small hole each pair, according to claim 1, characterized in that it is formed asymmetrically position of the end face of the ball screw nut Ball screw lubrication seal device. The space for enclosing lubricating oil is formed between the disc-shaped seal ring on both end surfaces of the ball screw nut and both end surfaces of the ball screw nut. The lubricating seal device for a ball screw according to claim 2.

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