KR102626025B1 - Ball recirculation type ball screw - Google Patents

Abstract

The present invention relates to a ball recirculating ball screw, and more specifically, to a ball recirculating ball screw configured to enable relative movement of a screw shaft and a ball nut while a plurality of balls recirculate.
The ball recirculating ball screw of the present invention includes a screw shaft and a ball nut configured to move relative to each other as a ball movement path is formed between them and a plurality of balls slide along the ball movement path, and a ball nut that is detachable from the ball nut. It is assembled and includes a plurality of return pieces that guide the balls to recirculate along the ball movement path, wherein the plurality of return pieces include a fixing screw coupled between two return pieces assembled side by side on the ball nut. A hole for piece-side screwing is formed, and the ball nut is provided with a nut-side screwing hole into which the fixing screw is coupled at a position corresponding to the piece-side screwing hole, and the fixing screw is provided in the It is characterized in that it sequentially passes through the piece side screw connection hole and the nut side screw connection hole and simultaneously couples the two return pieces to the ball nut.

Description

Ball recirculation type ball screw

The present invention relates to a ball recirculating ball screw, and more specifically, to a ball recirculating ball screw configured to enable relative movement of a screw shaft and a ball nut while a plurality of balls recirculate.

In general, a ball screw is a device that converts rotational movement into translational movement by placing a plurality of balls in a spiral groove formed between a male-threaded screw shaft and a female-threaded ball nut. It is used in vehicle steering systems, industrial machine tools, etc. It is a device that works.

In other words, the ball screw is a type of conveyance in which a spiral groove with an arc-shaped cross-section is formed on the outer surface of the screw shaft where the male thread is formed and the inner surface of the ball nut where the female thread is formed, and a plurality of balls are provided for rolling motion between them. It is an exercise screw.

At this time, it is a configuration to prevent the balls from being discharged to the outside of the ball nut by allowing the balls to recirculate. It is a return tube type that returns the balls that roll between the outer surface of the screw shaft and the inner surface of the ball nut to a certain position through a return tube. There is a composition.

The return tube is provided on the ball nut. In order to fix the return piece, which is a part that provides the return tube, to the ball nut, there is a fixing plate for fixing the position of the return piece by attaching it to the ball nut, and fixing the fixing plate to the ball nut. It is common for a number of bolts to be provided to do this.

However, according to the ball screw of the return tube type configuration, when the effective number of turns, which is the number of turns of balls circulated by the return piece, increases or decreases, it is necessary to separately manufacture a fixing plate for each specification.

Accordingly, there is a need for structural improvement to increase manufacturing and assembly efficiency by simplifying the structure for fixing the return piece to the ball nut.

The prior art related to this type of ball recirculating ball screw is disclosed in Republic of Korea Patent No. 10-0854782 and Republic of Korea Patent No. 10-1955401.

The present invention was developed to solve the above-mentioned problems, and provides a ball recirculating ball screw that can easily assemble the return piece for ball recirculation to the ball nut through a minimum number of bolts without a separate fixing member. It has a purpose.

The ball recirculating ball screw of the present invention for realizing the above-described purpose includes a screw shaft having a spiral outer groove formed on the outer circumferential surface, and a spiral inner groove corresponding to the outer groove of the screw shaft on the inner circumferential surface. a ball nut formed so that a plurality of balls move relative to the screw shaft as they slide along a ball movement path surrounded by the outer groove and the inner groove; and a plurality of return pieces that are detachably assembled to the ball nut and guide the balls to recirculate along the ball movement path.

In addition, the plurality of return pieces are provided so that a piece-side screwing hole into which a fixing screw is coupled is formed between the two return pieces assembled side by side on the ball nut, and the ball nut has a piece-side screwing hole. A nut side screwing hole into which the fixing screw is coupled is provided at a position corresponding to the fixing screw sequentially passing through the piece side screwing hole and the nut side screwing hole and the two return pieces. is configured to be simultaneously coupled to the ball nut.

In addition, when a screw engaging portion is formed at a corresponding position on one side and the other side of the return piece, and the two return pieces are assembled side by side to the ball nut, a screw engaging portion on one side of one of the two return pieces The screw coupling portion on the other side may meet to form a hole for screw coupling on the piece side.

Additionally, the screw coupling portions may be provided in a semicircular shape formed in opposite directions with the screw coupling hole as the center.

In addition, the return piece includes a pair of insertion portions inserted into the ball nut and a connection portion connecting the pair of insertion portions, and the insertion portions, the screw engaging portions, and the connection portion may be provided symmetrically. there is.

In addition, the ball nut is provided with a return piece assembly portion where the plurality of return pieces are assembled, wherein the return piece assembly portion is provided in a form in which a portion of a cylindrical side surface of the ball nut is depressed, and the return piece is provided with the ball nut. The outer surface that is not in contact with the nut may be provided to have a convex curved shape, so that the assembly of the return piece and the ball nut may be provided to form a cylindrical shape.

In addition, n-1 piece-side screwing holes are formed between the n return pieces coupled to the ball nut, and n-1 piece-side screwing holes are formed in the ball nut at positions corresponding to the n-1 piece-side screwing holes. -1 nut side screw connection holes are formed so that the n return pieces can be coupled to the ball nut using n-1 fixing screws. (where n is a natural number greater than or equal to 2)

In addition, when n is an even number, the n return pieces are paired into two adjacent ones, and one fixing screw is coupled to the piece side screw connection hole between the two paired return pieces, n/ The n return pieces can be coupled to the ball nut using two fixing screws.

In addition, when n is an odd number, pair the n return pieces with two adjacent ones, attach one fixing screw to the screw connection hole on the piece side between the two paired return pieces, and One additional fixing screw is attached to the screw connection hole on the piece side between the one remaining return piece and the adjacent return piece, and the n return pieces are connected using (n+1)/2 fixing screws. It may be coupled to the ball nut.

Additionally, the plurality of return pieces may be provided in the same shape.

Additionally, the ball nut may be made of a metal material, and the return piece may be injection molded from a synthetic resin material.

In addition, the return piece includes a pair of insertion portions inserted into the ball nut and a connection portion connecting the pair of insertions, and the ball nut has a pair of return piece insertion holes into which the pair of insertions are inserted. and a return piece support part for supporting the connection part, wherein the outer surface of the pair of insertion parts and the inner surface of the pair of return piece insertion holes are aligned, and the bottom surface of the connection part and the upper surface of the return piece support part are in close contact. It can be done as much as possible.

Additionally, the ball nut may be driven to rotate in place, and the screw shaft may be moved in translation in conjunction with the rotation of the ball nut.

Additionally, the screw shaft may be driven to rotate in place, and the ball nut may be moved in translation in conjunction with the rotation of the screw shaft.

According to the ball recirculating ball screw according to the present invention, the return piece can be easily assembled to the ball nut through minimal bolting without a separate fixing member, thereby simplifying the structure for fixing the return piece to the ball nut. and assembly efficiency can be increased.

In addition, ball recirculating ballscrews of various specifications can be easily formed by arranging multiple identical return pieces in succession without a separate fixing member.

1 is a perspective view of a ball recirculating ball screw according to a first embodiment of the present invention.
Figure 2 is an exploded view of a ball recirculating ball screw according to the first embodiment of the present invention.
Figure 3 is a perspective view of a ball nut according to the first embodiment of the present invention.
Figure 4 (a) is a top side view of the return piece according to the present invention
Figure 4 (b) is a lower side view of the return piece according to the present invention.
Figure 4 (c) is a lower perspective view of the return piece according to the present invention
Figure 4 (d) is a cross-sectional view of the return piece according to the present invention
Figure 5 is a front view of the ball nut according to the first embodiment of the present invention.
Figure 6 is a cross-sectional view showing the combined configuration of a ball nut and a return piece according to the first embodiment of the present invention.
Figure 7 is a diagram showing a ball circulation path formed by the first embodiment of the present invention.
Figure 8 is a view showing a ball movement path formed by the first embodiment of the present invention.
Figure 9 is a perspective view of a ball recirculating ball screw according to the second embodiment of the present invention.
Figure 10 is an exploded view of the ball recirculating ball screw according to the second embodiment of the present invention.

Hereinafter, the structure and operation of a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

The ball recirculating ball screw 1 according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 8.

In the ball recirculating ball screw 1 according to the first embodiment, a screw shaft 100 having a spiral external groove 110 formed on the outer peripheral surface is accommodated therein, and the external groove 110 of the screw shaft 100 A corresponding spiral internal groove 210 is formed on the inner peripheral surface, and as the plurality of balls B slide along the ball movement path P1 surrounded by the external groove 110 and the internal groove 210. A ball nut 200 configured to move relative to the screw shaft 100, and detachably assembled to the ball nut 200, so that the balls B are recirculated along the ball movement path P1. Includes a plurality of return pieces (300, 300-1,300-2) to guide.

Here, the plurality of return pieces (300,300-1,300-2) are piece side screws to which the fixing screw (400) is coupled between the two return pieces (300-1,300-2) assembled side by side to the ball nut (200). A coupling hole 310 is formed, and the ball nut 200 has a nut side screw coupling hole to which the fixing screw 400 is coupled at a position corresponding to the piece side screw coupling hole 310. (220) is provided, so that the fixing screw 400 sequentially penetrates the piece side screwing hole 310 and the nut side screwing hole 220, and the two return pieces (300-1,300-2) ) is simultaneously coupled to the ball nut 200.

In the ball recirculating ball screw 1, the ball nut 200 receives driving force from a drive source (not shown) and is driven to rotate in place, and the screw shaft 100 rotates the ball nut 200. It can be configured to enable translational movement in the left or right direction of the drawing (see FIG. 1), which is the axis (X) direction of rotation.

In the ball recirculating ball screw 1, the screw shaft 100 is rotated in place by receiving a driving force from a drive source (not shown), and the ball nut 200 is connected to the screw shaft 100. It may be configured to enable translational movement in the left or right direction of the drawing (see FIG. 1), which is the axis (X) direction of rotation, in conjunction with the rotation.

A plurality of return pieces 300, 300-1, 300-2 may be coupled to the ball nut 200 side by side in the axial (X) direction.

A plurality of return pieces 300,300-1,300-2 coupled to the ball nut 200 may be formed in the same shape and size.

The plurality of return pieces (300,300-1,300-2) are provided by injection molding of synthetic resin material, which can reduce the manufacturing cost and simplify the manufacturing process.

Referring to FIG. 1, the ball recirculating ball screw 1 according to the first embodiment of the present invention has two return pieces in which the two return pieces 300-1 and 300-2 are coupled to the ball nut 200. It is prepared as a composition.

Hereinafter, the ball recirculating ball screw 1 will be described on the premise of the two return piece configuration, and the case where three or more return pieces 300 are coupled to the ball nut 200 will be described later. This will be explained in the second embodiment.

FIG. 2 shows an exploded view showing a configuration in which the ball nut 200, the two return pieces 300,300-1,300-2, and the fixing screw 400 are combined, and FIG. 3 shows the ball nut 200. ) is shown, and Figure 4 shows an upper side view (Figure 4 (a)), a lower side view (Figure 4 (b)), a lower perspective view (Figure 4 (c)), and a cross-sectional view (Figure 4 (c)) of the return piece 300. Figure 4(d)) is shown.

Each return piece 300 is inserted between a pair of insertion portions 330 inserted into a pair of return piece insertion holes 230 provided in the ball nut 200 and the pair of insertion portions 330. It may include a connection portion 320 for connection.

The return piece 300 is formed with a ball circulation path (P2) inside which a plurality of balls (B) move, and the ball circulation path (P2) is connected to the ball movement path (P2) through the pair of insertion portions 330. Connected to P1).

The end of the insertion part 330 is provided so that the outside and the inside communicate for connection of the ball circulation path (P2) and the ball movement path (P1). In particular, the length of the outer end 331 is shorter than the inner end 332. It may be provided in a form shorter than the length of.

According to the above configuration, when the insertion portion 330 is inserted into the return piece insertion hole 230, the outer end 331 blocks the ball movement path P1 to prevent the movement of the ball B. Blocked, the ball B passes between the inner end 332 and the outer groove 110 of the screw shaft 100 and moves between the ball circulation path (P2) and the ball movement path (P1).

Screw coupling portions 311, 311a, and 311b may be formed on one side and the other side of the return piece 300 to form the piece side screw coupling hole 310.

When the two return pieces 300 are assembled side by side to the ball nut 200, the screw coupling portions 311, 311a, and 311b are the screw coupling portions 311a on one side of one of the two return pieces 300. and the other side screw coupling portion 311b may be formed at positions corresponding to each other to form the piece side screw coupling hole 310.

Accordingly, in the ball recirculating ball screw 1 provided with a two-return piece configuration, at least one piece-side screwing hole 310 may be formed between the two return pieces 300, preferably A single piece side screw hole 310 may be formed.

The screw coupling portions 311, 311a, 311b may be provided in a semicircular shape formed in opposite directions with the piece side screw coupling hole 310 as the center, and may be fixed to the piece side screw coupling hole 310. When the screw 400 is inserted, the head of the fixing screw 400 may have a stepped structure so that it is supported.

The return piece 200 may have the insertion portions 330, the screw engaging portions 311, 311a, and 311b, and the connecting portion 320 provided symmetrically. According to the symmetrical return piece 300 as described above, there is an advantage that the assembly position can be more easily set when assembling the ball nut 200.

The ball nut 200 is provided with a return piece assembly portion 200r where the plurality of return pieces 300,300-1,300-2 are assembled.

The return piece assembly portion 200r is a return piece insertion hole 230 into which the insertion portion 330 of the return piece 300 is inserted, and a return piece for supporting the connection portion 320 of the return piece 300. It may include a piece support portion 240 and a hole 220 for screwing the nut side.

The return piece support portion 240 may be provided to be fitted to the bottom of the connection portion 320 and be in close contact with the connection portion 320 when the return piece 300 and the ball nut 200 are assembled.

For example, the bottom of the connection part 320 is provided as a flat surface, and the return piece support part 240 is provided as a flat surface with a width such that the connection parts 320 of the plurality of return pieces 300, 300-1, 300-2 are supported side by side. You can.

Additionally, the connection portion 320 may be formed in a flange shape with a wide bottom and a relatively thin thickness in order to be more stably supported by the return piece support portion 240.

In addition, as shown in the drawing, when the return piece support portion 240 is provided in a form in which a portion of the cylindrical side surface of the ball nut 200 is recessed, the upper surface of the connection portion 320 of the return piece 300, that is, , the return piece 300 may be provided so that the outer surface that is not in contact with the ball nut 200 has a convex curved shape.

Accordingly, the assembly of the return piece 300 and the ball nut 200 forms a cylindrical shape, so that the screw shaft 100 and the ball nut 200 assembled with the return piece 300 are moved relative to each other. The driving system can be configured more simply.

The nut-side screw coupling hole 220 is formed between two return pieces 300 coupled to the return piece assembly 200r in the ball recirculating ball screw 1 provided in a two-return piece configuration. It may be formed in a position corresponding to the piece side screw hole 310.

Accordingly, at least one nut-side screwing hole 220 may be formed, and preferably, one nut-side screwing hole 220 may be formed. At this time, the nut-side screw coupling hole 220 may be formed in the center of the return piece support portion 240.

The return piece insertion holes 230 may be provided in twice the number of return pieces 300 that can be assembled in the corresponding return piece assembly unit 200r.

That is, the return piece assembly portion 200r has a pair of return piece insertion holes 230 corresponding to the pair of insertion portions 230 constituting the return piece 300. It is provided as per number.

For example, in the ball recirculating ball screw 1 provided with a two-return piece configuration according to the first embodiment, two pairs of return piece insertion holes 230 are provided in the return piece assembly portion 200r of the ball nut 200. That is, four return piece insertion holes 230 are provided.

In addition, the return piece insertion hole 230 is made of a through-type hole connecting the outside and inside of the ball nut 200, and the inner surface may be provided to be fitted with the outer surface of the insertion portion 330. .

As described above, according to the ball recirculating ball screw 1 according to the present invention, the bottom surface of the connecting portion 320 is in close contact with the return piece support portion 240, and the pair of insertion portions 330 are connected to the pair of return pieces 330. At the same time, the two return pieces (300,300-1,300-2) are fixed to the ball nut (200) using one fixing screw (400) by inserting the mold into the piece insertion hole (230) to stably set the coupling position. An efficient combination configuration can be provided.

Hereinafter, the movement of the plurality of balls B circulating along the ball movement path P1 and the ball circulation path P2 will be described with reference to FIGS. 5 to 8.

Referring to FIG. 5, the pair of return piece insertion holes 230 provided in the ball nut 200 may be provided obliquely in the axis (X) direction.

FIG. 6 shows a cross-sectional view showing a configuration in which the return piece 300 is coupled to the ball nut 200. The cross-section of the ball nut 200 shown is the cross-section A-A of FIG. 5, and the pair of This is a cross-section cut based on the return piece insertion hole (230).

Referring to FIG. 6, the pair of return piece insertion holes 230 are provided to penetrate the ball nut 200 and be connected to the ball movement path P1 through communication holes 501 and 502.

The communication ports 501 and 502 are provided at two different points on the ball movement path P1.

Accordingly, when the pair of insertion portions 330 are inserted into the pair of return piece insertion holes 230 and the ball nut 200 and the return piece 300 are coupled, the communication ports 501 and 502 ) The ball circulation path (P2) and the ball movement path (P1) are communicated through.

Here, the ball nut 200 of FIG. 5 is a two-return piece configuration in which two return pieces 300,300-1,300-2 are coupled side by side, and the B-B cross section is also formed the same as the A-A cross section, so that the combined configuration of FIG. 6 This can be applied equally.

Figure 7 is a front view of a ball recirculating ball screw 1 in which a ball nut 200 with two return pieces 300,300-1,300-2 assembled on the screw shaft 100 is coupled, the two return pieces (300-1;300-2) This is a drawing showing that ball circulation paths (P2-1;P2-2) are provided on the inside, respectively.

Referring to FIG. 7, each ball circulation path (P2-1; P2-2) has a communication port (501, 502; 503, 504) connected through a pair of insertion portions 330 provided in each return piece (300-1, 300-2). It is connected to different ball movement paths (P1-1; P1-2).

FIG. 8 is a diagram showing two ball movement paths (P1-1; P1-2) formed between the screw shaft 100 and the ball nut 200.

The two ball movement paths (P1-1; P1-2) are respectively connected to the ball circulation paths (P2-1; P2-2) of the two return pieces (300-1, 300-2).

Here, the two return pieces (300-1,300-2) are divided into a first return piece (300-1) and a second return piece (300-1), and the first return piece (300-1) and the The ball circulation path inside the second return piece (300-1) is divided into a first ball circulation path (P2-1) and a second ball circulation path (P2-2), and the two ball movement paths connected thereto are respectively divided into a first ball circulation path (P2-1) and a second ball circulation path (P2-2). It will be divided into 1 ball movement path (P1-1) and 2nd ball movement path (P2-2).

By the above-described configuration, the first ball movement path (P1-1) and the first ball circulation path (P2-1) are rings connected through communication holes 501 and 502 on the first ball movement path (P1-1). A first circulation path (not shown) of the structure is formed, and the second ball movement path (P1-2) and the second ball circulation path (P2-2) are communication holes on the second ball movement path (P1-2). A second circulation path (not shown) of a ring structure connected through (503, 504) is formed.

Accordingly, during the relative movement of the screw shaft 100 and the ball nut 200, the plurality of balls B move circularly along the first circulation path and the second circulation path.

Next, the ball recirculating ball screw 2 according to the second embodiment of the present invention will be described with reference to FIGS. 9 and 10.

Figure 9 shows a perspective view of the ball recycling type ball screw 2, and Figure 10 shows an exploded view of the ball recycling type ball screw 2.

The ball recirculating ball screw (2) according to the second embodiment follows the above-described first embodiment, but has three return pieces (300,300-1,300-2,300-3) coupled to the ball nut (200). It is different from the first embodiment in that it is structured.

Hereinafter, the three return pieces (300-1,300-2,300-3) are referred to as a first return piece (300-1), a second return piece (300-2), and a third return piece (300-3) from the left side of the drawing. Each is divided into

According to the three return piece configuration, at least one piece side screwing hole 310-1 may be formed between the first return piece 300-1 and the second return piece 300-2, Preferably, one piece side screw hole 310-1 may be formed.

At this time, one piece side screwing hole 310-1 formed between the first return piece 300-1 and the second return piece 300-2 is connected to the first piece side screwing hole 310. Let's call it -1).

In addition, at least one piece side screwing hole 310-2 may be formed between the second return piece 300-2 and the third return piece 300-3, preferably one. A hole 310-2 for screwing the piece side may be formed.

At this time, one piece side screwing hole 310-2 formed between the second return piece 300-2 and the third return piece 300-3 is connected to the second piece side screwing hole 310. Let's call it -2).

Additionally, according to the three return piece configuration, a return piece assembly portion 200r' where the three return pieces 300-1,300-2,300-3 are coupled to the ball nut 200 is formed.

The return piece assembly portion 200r' has three pairs of return piece insertion holes 230 into which three pairs of insertion portions 330, one pair each of the three return pieces 300-1,300-2,300-3, are inserted. This is provided.

In addition, the return piece assembly portion 200r' has a first nut side at a position corresponding to the first piece side screwing hole 310-1 and the second piece side screwing hole 310-2. A screw coupling hole 220-1 and a second nut side screw coupling hole 220-2 are provided.

Accordingly, two fixing screws (400-1, 400-2) are connected to the first piece side screwing hole (310-1), the first nut side screwing hole (220-1), and the first screwing hole (220-1). The three return pieces (300-1,300-2,300-3) are connected to the ball nut by sequentially engaging the two-piece side screwing hole (310-2) and the second nut-side screwing hole (220-2). It can be fixed at (200).

As described in the first and second embodiments above, when a plurality of return pieces 300 are assembled to the ball nut 200 by the ball recirculating ball screws 1 and 2 of the present invention, they A single piece-side screw connection hole may be formed between two return pieces that are adjacent to each other.

Accordingly, n-1 fixing screws 400 can be used to couple the n return pieces 300 to the ball nut 200. Here, n is a natural number of 2 or more.

At this time, the ball nut 200 may be provided with n-1 nut side screw coupling holes for coupling the n-1 fixing screws 400.

In addition, when an even number of return pieces 300 are assembled to the ball nut 200 by the ball recirculating ball screw of the present invention, the return pieces 300 are paired two by two adjacent to each other, and the two paired returns A plurality of return pieces 300 can be coupled to the ball nut 200 by coupling one fixing screw 400 to the screw coupling hole on the piece side between the pieces 300.

That is, n/2 fixing screws 400 can be used to couple the n return pieces 300 to the ball nut 200. Here, n is an even number of 2 or more.

In addition, when an odd number of return pieces 300 are assembled to the ball nut 200 by the ball recirculating ball screw of the present invention, the return piece 300 as in the case where the even number of return pieces 300 are assembled. They are paired two by two next to each other and coupled to the ball nut 200, and a fixing screw ( 400) A plurality of return pieces 300 can be coupled to the ball nut 200 by additionally coupling one.

That is, (n+1)/2 fixing screws 400 can be used to couple the n return pieces 300 to the ball nut 200. Here, n is an odd number of 3 or more.

As described above, according to the ball recirculating ball screw of the present invention, the return piece 300 can be easily assembled to the ball nut 200 through minimal bolting without a separate fixing member, so that the return piece 300 Manufacturing and assembly efficiency can be increased by simplifying the structure for fixing to the ball nut 200.

In addition, it is possible to more easily form ball recirculating ballscrews of various specifications by arranging a plurality of identical return pieces 300 in succession without a separate fixing member.

As mentioned above, the present invention is not limited to the above-described embodiments, and obvious modifications can be made by those skilled in the art without departing from the technical spirit of the present invention as claimed in the claims. Such modified implementations fall within the scope of the present invention.

B: Ball P1: Ball path
P2: Ball circuit X: Axis of rotation
1,2: Ball recirculating ball screw 100: Screw shaft
110: External groove of screw shaft 200: Ball nut
200r, 200r': Return piece assembly 210: Internal groove of ball nut
220: Nut side screw connection hole 230: Return piece insertion hole
240: Return piece support 300,300-1,300-2,300-3: Return piece
310: Piece side screw connection hole 311,311a, 311b: Screw connection part
320: connection part 330: insertion part
400,400-1,400-2: Fixing screw 501,502,503,504: Flue port

Claims (13)

A screw shaft having a spiral outer groove formed on the outer peripheral surface is accommodated inside, a spiral inner groove corresponding to the outer groove of the screw shaft is formed on the inner peripheral surface, and a plurality of balls are surrounded by the outer groove and the inner groove. a ball nut configured to move relative to the screw shaft as it slides along; and,
A plurality of return pieces are detachably assembled to the ball nut and guide the balls to recirculate along the ball movement path,
The plurality of return pieces are provided so that a piece-side screw connection hole, into which a fixing screw is coupled, is formed between the two return pieces assembled side by side on the ball nut,
The ball nut is provided with a nut-side screwing hole into which the fixing screw is coupled at a position corresponding to the piece-side screwing hole,
The fixing screw sequentially penetrates the piece side screwing hole and the nut side screwing hole and simultaneously couples the two return pieces to the ball nut,
n-1 piece-side screw coupling holes are formed between the n return pieces coupled to the ball nut,
In the ball nut, n-1 nut-side screw-fit holes are formed at positions corresponding to the n-1 piece-side screw-fit holes,
A ball recirculating ball screw, characterized in that the n return pieces can be coupled to the ball nut using n-1 fixing screws.
(However, n is a natural number of 2 or more) According to paragraph 1,
Screw coupling portions are formed at corresponding positions on one side and the other side of the return piece;
When the two return pieces are assembled side by side to the ball nut, the screw engaging portion on one side of one of the two return pieces and the screw engaging portion on the other side of the other one of the two return pieces meet to form a hole for screw coupling on the piece side. Ball recirculating ball screw. According to paragraph 2,
A ball recirculating ball screw, characterized in that the screw coupling portions are provided in a semicircular shape formed in opposite directions with the screw coupling hole as the center. According to paragraph 2,
The return piece includes a pair of insertions inserted into the ball nut and a connection portion connecting the pair of insertions, wherein the insertion portions, the screw engaging portions, and the connection portion are provided symmetrically. Ball recirculating ball screw. According to paragraph 1,
The ball nut is provided with a return piece assembly portion to which the plurality of return pieces are assembled, and the return piece assembly portion is provided in a form in which a portion of a cylindrical side surface of the ball nut is recessed,
The return piece is provided so that its outer surface, which is not in contact with the ball nut, has a convex curved shape,
A ball recirculating ball screw, characterized in that the assembly of the return piece and the ball nut forms a cylindrical shape. delete According to paragraph 1,
If n is an even number,
Pair the n return pieces with two adjacent ones, and attach one fixing screw to the screw connection hole on the piece side between the two paired return pieces,
A ball recirculating ball screw, characterized in that the n return pieces can be coupled to the ball nut using n/2 fixing screws. According to paragraph 1,
If n is an odd number,
Pair the n return pieces with two adjacent ones, attach one fixing screw to the screw connection hole on the piece side between the two paired return pieces, and attach the one remaining return piece and its neighboring return piece. Add one additional fixing screw to the screw connection hole on the piece side between the return pieces,
A ball recirculating ball screw, characterized in that the n return pieces can be coupled to the ball nut using (n+1)/2 fixing screws. According to paragraph 1,
A ball recirculating ball screw, characterized in that the plurality of return pieces are provided in the same shape. According to clause 9,
The ball nut is made of metal,
A ball recirculating ball screw, wherein the return piece is injection molded from a synthetic resin material. According to paragraph 1,
The return piece includes a pair of insertion parts inserted into the ball nut and a connection part connecting the pair of insertion parts,
The ball nut is provided with a pair of return piece insertion holes into which the pair of insertions are inserted and a return piece support portion to support the connection portion,
A ball recirculating type ball screw, wherein the outer surface of the pair of insertion portions and the inner surface of the pair of return piece insertion holes are aligned, and the bottom surface of the connection portion and the upper surface of the return piece support portion are in close contact. According to paragraph 1,
A ball recirculating ball screw, wherein the ball nut is driven to rotate in place, and the screw shaft is moved in translation in conjunction with the rotation of the ball nut. According to paragraph 1,
A ball recirculating ball screw, wherein the screw shaft is driven to rotate in place, and the ball nut is translated in conjunction with the rotation of the screw shaft.

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