JPWO2015181860A1 - Ball screw device - Google Patents

Abstract

Provided is a ball screw device capable of easily attaching and detaching a dustproof member regardless of the thickness of a nut and extending a lubrication life by suitably holding a lubricant supply member. Therefore, it has a screw shaft (10) and a nut (20) that is movably engaged with the screw shaft (10) via a ball (30), and the inner peripheral surface of the nut (20). In (20a), an engagement groove (22) is formed in the circumferential direction with a predetermined distance from the end in the axial direction. In the nut (20), an engagement piece (41) formed on the outer peripheral surface (40a) is engaged with the engagement groove (22), and a gap between the screw shaft (10) and the nut (20) is formed. A cylindrical dustproof member (40) to be sealed is attached. Lubrication is performed by the inner peripheral surface (40b) of the dustproof member (40), the flange portion (43) provided at the end (40c) of the dustproof member (40), and the outer peripheral surface (10a) of the screw shaft (10). The agent supply member (50) and the grease are held in the dust-proof member (40).

Description

  The present invention relates to a ball screw device.

A ball screw device used as a mechanical element that converts rotational motion into linear motion generally has a screw shaft and a cylindrical nut provided on the outer periphery of the screw shaft. A plurality of balls are incorporated between the formed spiral ball rolling groove and the spiral ball rolling groove formed on the inner peripheral surface of the nut.
In such a ball screw device, if a foreign matter such as dust adhering to the surface of the screw shaft enters the inside of the nut, the smooth rolling motion of the ball is hindered. Often attached to the end face of

An example of a ball screw device provided with such a dustproof member is described in Patent Document 1. In this ball screw device, as shown in FIG. 7, large-diameter step portions 103 for attaching a seal are formed at both ends of a nut 102 screwed to a screw shaft 100 via a ball 101. In addition, radial screw holes 104 that open to the inner peripheral surface of the large-diameter stepped portion 103 are formed in both end portions of the nut 102. That is, one or two radial screw holes 104 penetrating from the outer peripheral surface 102a of the nut 102 and the flange peripheral surface (not shown) to the respective large diameter step portions 103 are formed. After the seal 105 is fitted to the large-diameter step portion 103, the seal 105 is fixed in the circumferential direction and the axial direction by fastening a set screw 106 to the screw hole 104.
As another embodiment of the lubricating seal device, Patent Document 2 discloses a structure using a seal plate. This lubricating seal device has a hole shape in which a contact portion corresponding to a right-angle cross-sectional shape of a thread groove of a screw shaft formed on an inner diameter surface of a seal plate protrudes inward.

Japanese Patent Laid-Open No. 2003-130171, FIG. Japanese Patent Laying-Open No. 2003-232428, FIG. 1 (b)

However, since the ball screw device described in Patent Document 1 is provided with the screw hole 104 in the nut 102, the labor required for the processing sometimes reduces the yield. In particular, in forming the screw hole 104, when the thickness of the nut 102 is large, it is necessary to process not only the tapped hole processed with the female screw groove but also the drill hole. Variations occurred and there was room for improvement.
Further, in the technique disclosed in Patent Document 2, a plurality of seal plates are used in an overlapping manner, and the protruding portions of the seal plates are overlapped with each other along the lead of the thread groove, and the outer side of the seal plate is overlapped. Since it is fixed by adhering to the inner surface of the case, it is necessary to shift each sheet along the leads, which increases the cost in assembling work.
Therefore, the present invention has been made paying attention to the above-mentioned problems, and the purpose thereof is to facilitate the attachment / detachment of the dust-proof member regardless of the thickness of the nut, and to suitably use the lubricant supply member. An object of the present invention is to provide a ball screw device that can extend the lubrication life by holding.

In order to achieve the above object, a ball screw device of an embodiment includes a screw shaft, a nut provided on an outer periphery of the screw shaft, and a spiral ball rolling groove formed on an outer peripheral surface of the screw shaft. A plurality of balls provided between a spiral ball rolling groove formed on the inner peripheral surface of the nut,
On the inner peripheral surface of the nut, an engagement groove is formed in the circumferential direction with a predetermined distance from the axial end,
A dust-proof member that has a cylindrical shape and is elastically deformed and engaged with the engagement groove by the engagement piece formed on the outer peripheral surface thereof to seal the gap between the screw shaft and the nut is attached to the nut. And
The radial thickness of the end surface of the dust-proof member on the side where the engagement piece is not provided is larger than the radial thickness of the end surface on the side where the engagement piece is provided,
At least one of the lubricant supply member and the grease is held in the dust-proof member by the inner peripheral surface of the dust-proof member, the flange portion provided at the end of the dust-proof member, and the outer peripheral surface of the screw shaft. The

In order to achieve the above object, a ball screw device of an embodiment includes a screw shaft, a nut provided on an outer periphery of the screw shaft, and a spiral ball rolling groove formed on an outer peripheral surface of the screw shaft. In a ball screw device comprising a plurality of balls provided between a spiral ball rolling groove formed on the inner peripheral surface of the nut,
On the inner peripheral surface of the nut, an engagement groove is formed in the circumferential direction with a predetermined distance from the axial end,
A dust-proof member that has a cylindrical shape and is elastically deformed and engaged with the engagement groove by the engagement piece formed on the outer peripheral surface thereof to seal the gap between the screw shaft and the nut is attached to the nut. And
The radial thickness of the end surface of the dust-proof member on the side where the engagement piece is not provided is larger than the radial thickness of the end surface on the side where the engagement piece is provided,
At least one of the lubricant supply member and the grease is held in the dust-proof member by the inner peripheral surface of the dust-proof member, the flange portion provided at the end of the dust-proof member, and the outer peripheral surface of the screw shaft. The

In addition, a ball screw device according to another embodiment for achieving the above object includes a screw shaft, a nut provided on the outer periphery of the screw shaft, and a spiral ball rolling formed on the outer peripheral surface of the screw shaft. A plurality of balls provided between the dynamic groove and a spiral ball rolling groove formed on the inner peripheral surface of the nut,
On the inner peripheral surface of the nut, an engagement groove is formed in the circumferential direction with a predetermined distance from the axial end,
A dust-proof member that has a cylindrical shape and is elastically deformed and engaged with the engagement groove by the engagement piece formed on the outer peripheral surface thereof to seal the gap between the screw shaft and the nut is attached to the nut. And
The radial thickness of the end surface of the dust-proof member on the side where the engagement piece is not provided is larger than the radial thickness of the end surface on the side where the engagement piece is provided,
A cylindrical inner peripheral wall is provided in a flange portion provided at an end of the dustproof member, and a lubricant supply member and grease are interposed between the inner peripheral wall, the inner peripheral surface of the dustproof member, and the flange portion. At least one of them is provided.

In addition, a ball screw device according to another embodiment for achieving the above object includes a screw shaft, a nut provided on the outer periphery of the screw shaft, and a spiral ball rolling formed on the outer peripheral surface of the screw shaft. In a ball screw device comprising a plurality of balls provided between a dynamic groove and a spiral ball rolling groove formed on the inner peripheral surface of the nut,
On the inner peripheral surface of the nut, an engagement groove is formed in the circumferential direction with a predetermined distance from the axial end,
A dust-proof member that has a cylindrical shape and is elastically deformed and engaged with the engagement groove by the engagement piece formed on the outer peripheral surface thereof to seal the gap between the screw shaft and the nut is attached to the nut. And
The radial thickness of the end surface of the dust-proof member on the side where the engagement piece is not provided is larger than the radial thickness of the end surface on the side where the engagement piece is provided,
A cylindrical inner peripheral wall is provided in a flange portion provided at an end of the dustproof member, and a lubricant supply member and grease are interposed between the inner peripheral wall, the inner peripheral surface of the dustproof member, and the flange portion. At least one of them is provided.

In the ball screw device, a plurality of dividing walls that divide a space formed by the flange portion, the inner peripheral wall, and the inner peripheral surface into a plurality of accommodating portions in the circumferential direction are provided. At least one of the lubricant supply member and the grease may be held.
Further, in the ball screw device, the plurality of accommodating portions include a first accommodating portion in which the engaging piece is formed on the outer peripheral surface, and a second accommodating portion in which the engaging piece is not formed on the outer peripheral surface. It is preferable that grease is accommodated in the first accommodating portion, and a divided body of the lubricant supply member is accommodated in the second accommodating portion.
Moreover, in the said ball screw apparatus, it is preferable that the volume of a 1st accommodating part is smaller than the volume of a 2nd accommodating part.

  According to the present invention, there is provided a ball screw device capable of easily attaching and detaching a dustproof member regardless of the thickness of a nut and extending a lubrication life by suitably holding a lubricant supply member. can do.

1A and 1B are diagrams showing a configuration of a ball screw device according to a first embodiment, where FIG. 1A is a cross-sectional view along an axial direction, and FIG. 1B is a front view when a dustproof member is installed on a nut. It is a figure which shows the structure of the dust-proof member in 1st Embodiment of a ball screw apparatus, a dust-proof member extraction jig | tool (henceforth a jig | tool), and a lubricant supply member, (a) is the left side of a dust-proof member. FIG. 3B is a front view of the dust-proof member, FIG. 3C is a sectional view along the axial direction of the lubricant supply member, and FIG. 4D is a front view of the lubricant supply member. (E) is a perspective view of a dustproof member extraction jig, and (f) is an enlarged view of a main part of (e). It is a figure which shows the attachment procedure of the dustproof member in 1st Embodiment of a ball screw apparatus, (a) is sectional drawing in alignment with the axial direction before attaching a dustproof member to a nut, (b) is a dustproof member as a nut. It is sectional drawing which follows the axial direction after mounting | wearing. It is a figure which shows the removal procedure of the dustproof member in an embodiment with a ball screw apparatus, (a) is sectional drawing in alignment with the axial direction of the state with which the dustproof member was mounted | worn to the nut, (b) is before a jig | tool is inserted. Sectional drawing along an axial direction, (c) is a sectional view along the axial direction when a jig is inserted, and (d) is a sectional view along the axial direction when a dustproof member is removed from a nut. It is a figure which shows the structure in 2nd Embodiment of a ball screw apparatus, (a) is sectional drawing which follows an axial direction, (b) is a front view, (c) is a left sectional view of a dust-proof member, (d) is a figure. The front view of a dustproof member, (e) is a rear view of a dustproof member. It is a figure which shows the structure of the dust-proof member and lubricant supply member in 3rd Embodiment of a ball screw apparatus, (a) is a rear view of a dust-proof member, (b) is a front view of a lubricant supply member, (c). FIG. 3 is a cross-sectional view along the axial direction of the lubricant supply member. It is sectional drawing which follows the axial direction which shows the structure of the conventional ball screw apparatus.

Embodiments of a ball screw device according to the present invention will be described below with reference to the drawings.
1A and 1B are diagrams showing a configuration of a ball screw device according to a first embodiment, where FIG. 1A is a cross-sectional view along an axial direction, and FIG. 1B is a front view when a dustproof member is installed on a nut. In FIG. 1B, the ball screw is omitted. FIG. 2 is a diagram showing the configuration of a dustproof member, a dustproof member extraction jig (hereinafter also referred to as a jig), and a lubricant supply member in the first embodiment of the ball screw device. ) Is a left side view of the dustproof member, (b) is a front view of the dustproof member, (c) is a sectional view along the axial direction of the lubricant supply member, and (d) is a front view of the lubricant supply member. (E) is a perspective view of a dustproof member extraction jig, and (f) is an enlarged view of a main part of (e).

As shown in FIGS. 1A and 1B, the ball screw device 1 of the present embodiment includes a screw shaft 10, a nut 20, a plurality of balls 30, and a dustproof member 40.
The screw shaft 10 has a spiral ball rolling groove 11 on the outer peripheral surface 10a, and a spiral ball rolling groove 21 is formed on the inner peripheral surface of the nut 20 provided on the outer periphery of the screw shaft 10. The same lead as the rolling groove 11 is formed.
The ball rolling grooves 11 and 21 are opposed to each other, and the plurality of balls 30 provided between the ball rolling grooves 11 and 21 are rotated by the relative rotation of the screw shaft 10 with respect to the nut 20. It rolls between the grooves 11 and 21. Then, the ball 30 that has rolled between the ball rolling grooves 11 and 21 passes through a ball return tube (not shown) assembled to the nut 20 and is returned to its original position. Between these ball rolling grooves 11 and 21 and the ball return tube form a rolling path.

[Engagement groove]
A circular engagement groove 22 is provided in the circumferential direction on the inner peripheral surface of the nut 20 with a predetermined distance from the end in the axial direction. One engagement groove 22 is preferably provided from each end of the nut 20, and a plurality of engagement grooves 22 are provided as necessary. A dustproof member 40 is fixed to the engagement grooves 22. Here, the predetermined distance is set based on the dimension of the dustproof member 40 in the axial direction.

<Dustproof material>
As shown in FIGS. 2A and 2B, the dustproof member 40 has a cylindrical shape. A plurality of engagement pieces 41 (five in this embodiment) are provided at equal intervals on the outer peripheral surface 40 a of the dust-proof member 40. These engagement pieces 41 have elasticity and can be engaged with the engagement grooves 22. The engaging piece 41 is preferably formed integrally with a material having elasticity together with the dustproof member 40. Further, the radial thickness of the end surface of the dust-proof member 40 where the engagement piece 41 is not provided (the end surface on the end portion 40c side) is larger than the radial thickness of the end surface on the side where the engagement piece 41 is provided. Is also enlarged. This is because, when the engagement piece 41 is elastically deformed, the bending moment of the end surface of the dustproof member 40 on the side where the engagement piece 41 is not provided is larger than the bending moment of the engagement piece 41, so This is because the second moment is increased.
Further, the dust-proof member 40 has a groove 42 in which the outer peripheral surface 40a is cut out along the axial direction on the end surface opposite to the end surface on the side where the engagement pieces 41 are provided. Are provided (five in this embodiment).
Further, a flange portion 43 extending toward the central axis O is provided at the end portion 40 c of the dustproof member 40 in a disc shape with an opening diameter substantially the same as the diameter of the screw shaft 10.

<Lubricant supply member>
As shown in FIG. 1A and FIG. 2C and FIG. 2D, the inner peripheral surface 40b of the dustproof member 40, the flange portion 43 provided at the end 40c of the dustproof member 40, and the screw shaft 10 The lubricant supply member 50 is held in the dustproof member 40 by the outer peripheral surface 10a. In the present embodiment, not only the lubricant supply member 50 but also grease may be held in the dustproof member 40. The lubricant supply member 50 is made of, for example, a ring-shaped material that absorbs and holds a lubricant such as lubricating oil or grease. The lubricant is supplied to the surface of the screw shaft 10 to provide appropriate lubricity. Demonstrate.

Next, a procedure for attaching the dust-proof member 40 to the nut 20 will be described with reference to FIG.
FIGS. 3A and 3B are diagrams showing a procedure for attaching the dustproof member in the present embodiment, where FIG. 3A is a cross-sectional view along the axial direction before the dustproof member is attached to the nut, and FIG. 3B is a diagram of attaching the dustproof member to the nut. It is sectional drawing which follows a later axial direction.
As shown in FIGS. 3A and 3B, the dust-proof member 40 holds the outer peripheral surface 40a and the inner peripheral surface 20a of the nut 20 while keeping the lubricant supply member 50 inside. It is fitted in the nut 20. At this time, the plurality of engagement pieces 41 are engaged with the engagement grooves 22 while being elastically deformed, whereby the dustproof member 40 is fixed to the nut 20. In this way, the dustproof member 40 attached to the nut 20 seals the gap between the screw shaft 10 and the nut 20.
Here, when the lubricant supply member 50 is housed (held) inside the dust-proof member 40, the engagement piece 41 is biased inward when the dust-proof member 40 is attached to the nut 20. However, since the lubricant supply member 50 itself has elasticity, there is no particular problem.

<Removal of dustproof member>
Next, a procedure for removing the dustproof member 40 from the nut 20 will be described with reference to FIG.
2 (e) and 2 (f) are views showing a jig used when removing the dustproof member in the present embodiment, (e) is a perspective view, and (f) is a partially enlarged view of (e). It is. FIG. 4 is a view showing a procedure for removing the dust-proof member in the present embodiment, (a) is a sectional view along the axial direction of the dust-proof member mounted on the nut, and (b) is a jig insertion. Sectional drawing along the previous axial direction, (c) is a sectional view along the axial direction when the jig is inserted, and (d) is a sectional view along the axial direction when the dustproof member is removed from the nut.

When removing the dustproof member in the present embodiment, a cylindrical jig 60 shown in FIG. 2 (e) is used. In the jig 60, the diameter of the outer peripheral surface 60 a is substantially equal to the outer diameter of the dust-proof member 40 (diameter of the outer peripheral surface 40 a). In addition, a plurality of protrusions 61 are provided on one end surface 60 b of the jig 60 so as to protrude in the axial direction corresponding to the formation position of the groove portion 42 of the dust-proof member 40. As shown in FIG. 2 (f), the tip portions of these protrusions 61 are curved from the inner surface (the surface on the central axis side of the jig 60) to the outer surface.
When removing the dustproof member 40 from the nut 20 using such a jig, first, the positions of the plurality of groove portions 42 relative to the dustproof member 40 (see FIG. 4A) attached to the nut 20 are set. The positions of the plurality of protrusions 61 are aligned (see FIG. 4B).

Next, the plurality of protrusions 61 are inserted between the plurality of groove portions 42 and the inner peripheral surface 20 a of the nut 20. At this time, as each protrusion 61 presses the inner wall 42a of each groove portion 42 in the direction of the central axis of the jig 60, each engaging piece 41 also has a central axis O (see FIG. a) (see FIG. 4 (c)). Here, as described above, since the curved surface is formed at the tip of each protrusion 61, when the protrusion 61 presses the inner wall 42a of the groove part 42 in the direction of the central axis, the engagement groove 22 engages. The engagement of the joining piece 41 is easily released.
Here, the dustproof member 40 is installed in the nut 20 so as to engage with the ball rolling groove 11 in order to seal between the screw shaft 10 and the nut 20. For this reason, when the dustproof member 40 is rotated counterclockwise by the jig 60, for example, the dustproof member 40 holding the lubricant supply member 50 along the ball rolling groove 11 is rotated and removed from the nut 20. (Refer FIG.4 (d)).

  As described above, according to the present embodiment, the dust-proof member can be easily attached and detached regardless of the thickness of the nut, and the lubrication supply member is suitably held, thereby extending the lubrication life. It is possible to provide a ball screw device capable of Also in the conventional ball screw device, the inner diameter portion of the dust-proof component is stealed, and it was possible to store grease in this portion. However, in such a structure, there are many portions (areas) that are in direct contact with the outer peripheral surface of the screw shaft, and the grease may not be retained for a long time. Thus, as in the present embodiment, the above-described effect is achieved by adopting a mode in which the lubricant supply member 50 is held inside the dustproof member 40.

(Second Embodiment)
Next, a second embodiment of the ball screw device will be described with reference to the drawings. In addition, since this embodiment differs only in the structure of the dustproof member 40 from 1st Embodiment, description is abbreviate | omitted about the same structure which attached | subjected the same code | symbol as the above-mentioned embodiment. FIGS. 5A to 5E are views showing the configuration of the ball screw device according to the second embodiment, where FIG. 5A is a sectional view along the axial direction, FIG. 5B is a front view, and FIG. The left sectional view of a dustproof member, (d) is a front view of a dustproof member, and (e) is a rear view of a dustproof member.

As shown in FIGS. 5A to 5E, the ball screw device 1 of the present embodiment is provided with a cylindrical inner peripheral wall 44 in the flange portion 43. The inner peripheral wall 44 is erected in a cylindrical shape at an opening that penetrates the dust-proof member 40. That is, the inner peripheral wall 44 is erected in the same direction as the engagement piece 41 at substantially equal intervals with the outer peripheral surface 40a (inner peripheral surface 40b). An annular lubricant supply member 50 is provided between the inner peripheral wall 44, the inner peripheral surface 40 b of the dust-proof member 40, and the flange portion 43. In the space S formed by the inner peripheral wall 44, the inner peripheral surface 40b of the dust-proof member 40, and the flange portion 43, not only the lubricant supply member 50 but also grease may be provided.
As described above, according to the present embodiment, since the lubricant supply member or the grease is held by the inner peripheral wall provided along the outer peripheral surface of the screw shaft, the lubrication life can be prevented without interfering with the screw shaft. Can be provided.
Note that the presence of the inner peripheral wall as in the present embodiment reduces the portion (area) where the lubricant supply member or grease is in direct contact with the screw shaft, and the lubricant can be held for a long time.

(Third embodiment)
Next, a third embodiment of the ball screw device will be described with reference to the drawings. In the present embodiment, the description of the same configuration given the same reference numeral as that in the above embodiment is omitted. FIGS. 6A to 6C are diagrams showing configurations of a dustproof member and a lubricant supply member in the third embodiment of the ball screw device, wherein FIG. 6A is a rear view of the dustproof member, and FIG. The front view of a lubricant supply member, (c) is a sectional view along the axial direction of the lubricant supply member.

As shown to Fig.6 (a), the ball screw apparatus 1 of this embodiment has the some accommodating part S1 and accommodation in the circumferential direction in the space S formed by the flange part 43, the inner peripheral wall 44, and the inner peripheral surface 40b. A plurality of dividing walls 45 that are divided into the portions S2 are provided. The dividing wall 45 is a plurality of walls that connect the inner peripheral wall 44 and the inner peripheral surface 40b to divide the space S into a plurality of accommodating portions S1 and accommodating portions S2 in the circumferential direction.
Here, the accommodating portion S1 is a narrow space accommodating portion (first accommodating portion) in which the engagement piece 41 is formed on the outer side (the outer peripheral surface 40a), and the accommodating portion S2 is related to the outer side (the outer peripheral surface 40a). This is a large space accommodating portion (second accommodating portion) in which the joining piece 41 is not formed.
And the division body 51 of the divided | segmented lubricant supply member 50 shown in FIG.6 (b), (c) is accommodated in accommodating part S2. On the other hand, in the accommodating portion S1, grease that is a fluid is accommodated as necessary. In the ball screw device of this embodiment, the inner peripheral convex portion 52 of the lubricant supply member 50 is disposed inside the axial nut inside the axial nut inner end portion of the inner peripheral wall 44, and the screw shaft Facing the outer periphery.

As described above, according to the present embodiment, a plurality of lubricant supply members (divided bodies) can be held in the dust-proof member, so that the surface area of the lubricant supply member is increased and the lubrication life is further extended. be able to. In addition to the lubricant supply member, the fluid grease can be held in the dust-proof member, so that the lubrication life can be further extended.
The ball screw device according to the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention. For example, in the above-described embodiment, the number of locking pieces provided on the dustproof member is five, but the number is not limited as long as the engagement of the dustproof member is not impaired.

DESCRIPTION OF SYMBOLS 1 Ball screw apparatus 10 Screw shaft 11 Ball rolling groove 20 Nut 21 Ball rolling groove 22 Engagement groove 30 Ball 40 Dust-proof member 40a Outer peripheral surface 40b Inner peripheral surface 40c End part 41 Engagement piece 42 Groove part 43 Flange part 44 Inner peripheral wall 45 Partition wall 50 Lubricant supply member 60 Jig

Claims (5)

A screw shaft, a nut provided on the outer periphery of the screw shaft, a spiral ball rolling groove formed on the outer peripheral surface of the screw shaft, and a spiral ball rolling formed on the inner peripheral surface of the nut A plurality of balls provided between the grooves,
On the inner peripheral surface of the nut, an engagement groove is formed in the circumferential direction with a predetermined distance from the axial end.
A dust-proof member that has a cylindrical shape and that is elastically deformed on the outer peripheral surface thereof and engaged with the engagement groove to seal the gap between the screw shaft and the nut is attached to the nut. And
The radial thickness of the end surface of the dust-proof member on the side where the engagement piece is not provided is larger than the radial thickness of the end surface on the side where the engagement piece is provided,
At least one of the lubricant supply member and the grease is held in the dust-proof member by the inner peripheral surface of the dust-proof member, the flange portion provided at the end of the dust-proof member, and the outer peripheral surface of the screw shaft. A ball screw device. A screw shaft, a nut provided on the outer periphery of the screw shaft, a spiral ball rolling groove formed on the outer peripheral surface of the screw shaft, and a spiral ball rolling formed on the inner peripheral surface of the nut A plurality of balls provided between the grooves,
On the inner peripheral surface of the nut, an engagement groove is formed in the circumferential direction with a predetermined distance from the axial end.
A dust-proof member that has a cylindrical shape and that is elastically deformed on the outer peripheral surface thereof and engaged with the engagement groove to seal the gap between the screw shaft and the nut is attached to the nut. And
The radial thickness of the end surface of the dust-proof member on the side where the engagement piece is not provided is larger than the radial thickness of the end surface on the side where the engagement piece is provided,
A cylindrical inner peripheral wall is provided in a flange portion provided at an end of the dustproof member, and a lubricant supply member and grease are interposed between the inner peripheral wall, the inner peripheral surface of the dustproof member, and the flange portion. At least one of them is provided.   A plurality of dividing walls that divide a space formed by the flange portion, the inner peripheral wall, and the inner peripheral surface into a plurality of accommodating portions in the circumferential direction are provided, and the lubricant supplying member and grease divided in the accommodating portion The ball screw device according to claim 2, wherein at least one of the above is held.   The plurality of accommodating portions include a first accommodating portion in which the engaging piece is formed on the outer peripheral surface and a second accommodating portion in which the engaging piece is not formed on the outer peripheral surface. The ball screw device according to claim 3, wherein grease is stored, and a divided body of the lubricant supply member is stored in the second storage portion.   The ball screw device according to claim 4, wherein the volume of the first housing portion is smaller than the volume of the second housing portion.

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