TWI512215B - Linear drive ball spline device - Google Patents

Description

Linear drive ball spline device

The present invention is a linear transmission element, and more particularly a linear drive ball spline device.

The present invention relates to a transmission element in which a spline shaft and a nut member are combined in a relatively linear motion by a plurality of balls, and a ball spline device such as a linear guide portion of a working machine or various industrial machines or a torque transmitting portion of an industrial robot is used. .

It is known that such a ball spline device is known as a ball spline device disclosed in Japanese Laid-Open Patent Publication No. SHO 61-179414 or No. Sho 58-137616. The ball spline device includes: a spline shaft having a plurality of rolling grooves extending in a longitudinal direction; and a nut member having a plurality of balls assembled to the spline shaft and having an infinite loop path of the ball According to this configuration, the nut member can be moved along the longitudinal direction around the spline shaft in accordance with the infinite circulation of the balls.

In addition, the infinite loop path of the ball provided by the nut member is: a load passage formed by a rolling groove of a nut member provided by the ball and a rolling groove of the spline shaft; and a ball return passage formed in parallel with the load passage; And a U-shaped direction changing track that is connected to the load passage and the ball return passage. Then, the above-described direction switching track is disposed at both ends of the load passage and the ball return passage to constitute a ball infinite loop.

In the above-described document ball spline device, a synthetic resin holder is attached to a gap between an inner peripheral surface of a cylindrical nut member and a spline shaft that is formed in the inner peripheral surface, and the retainer and the screw are used. The cooperation of the cap members forms a ball return passage and a direction change passage.

Further, in order to move the ball rolling in the above-described load passage to the ball return passage via the direction change, it is necessary to disengage the ball from the ball rolling groove of the spline shaft. Therefore, in the conventional ball spline device, the retainer is provided with a ball scooping portion continuous with the direction changing passage, and the ball rolling in the ball rolling groove passes over the scooping portion from the ball rolling groove. The detachment is formed to be housed in a direction change path formed by the cooperation of the retainer and the nut member.

However, in the conventional ball spline device described above, since the retainer and the nut member cooperate to form the ball return passage, the ball return passage must at least have a thickness of the retainer from the spline shaft toward the radial direction thereof. the distance. Further, the above-described directional change track or ball return passage is formed in the retainer, and in order to realize the complicated shape, it is produced by injection molding of a synthetic resin using a mold. Therefore, the conventional ball spline has the following problem: if the retainer provided on the inner surface of the nut member is deformed, the retainer will contact the spline shaft, thereby obstructing the movement of the nut member, so that the retainer is difficult to form. Extremely thin. Therefore, in the conventional ball spline device in which the retainer is housed between the spline shaft and the nut member, the outer diameter of the nut member is affected by the thickness of the retainer, so that the outer diameter of the nut member becomes larger. .

The conventional ball spline device utilizes the above retainer to make the ball infinitely circulate, but the retainer is made of plastic injection molding, and its length and size are fixed, so it cannot be Suitable for nuts of different lengths, the versatility is not high.

The present invention has been made in view of the above problems, and it is an object of the invention to provide an advantage that the original function can be sufficiently exhibited, and the outer diameter of the nut member can be minimized, and the assembly can be inexpensive and simple. A ball spline device capable of maintaining quality reliability.

In order to achieve the above object, the present invention is a linear drive ball spline device comprising: a spline shaft extending in a direction into a strip-like structure defining the direction of the extension as an axial direction, the surface of the spline shaft a plurality of rolling grooves extending along the axial direction; a moving body comprising a body, two reflow members and a plurality of rolling elements, the system is provided with a perforation for the spline shaft, the inner surface of the perforation a rolling groove is formed opposite to the rolling groove, the rolling groove and the rolling groove form a load path, and two ends of the hole are respectively provided with a mounting hole, the diameter of the mounting hole is larger than the diameter of the hole and the two are connected to each other The body is further provided with a plurality of return holes disposed opposite to the rolling groove and parallel to the rolling groove, the two ends of the return hole are connected to the mounting hole, and the cross-section of the return hole is a circular shape; The components are respectively disposed in the two mounting holes, and the reflowing member is provided with a return flow path relative to the rolling groove. The return channel contour is a U-shaped shape, and the two ends of the return channel are respectively connected to the load path and the return hole. Composition one a loop path; the plurality of scroll members are disposed in the loop path.

According to the above structure, the outer diameter of the main body can be reduced without providing a retainer between the spline shaft and the main body, and the reflowing member is disposed at the mounting holes at both ends of the main body. When the length of the body varies only in the axial direction, the reflow member can still be used for the body, thereby improving the versatility of the reflow member.

Moreover, in order to obtain better smoothness when the rolling element is operated in the circulation path, the present invention designs a special path for the return path which is most likely to cause the rolling member to run unsmoothly, and the description is as follows: the return path Divided into four segments, the four segments are respectively connected as a climbing segment, a first rotating segment, a second rotating segment and a connecting segment; the width of the returning channel is greater than the diameter of the rolling member. The climbing section is partially accommodated in the rolling groove, the climbing section has a climbing height and a climbing length, the climbing height is less than the climbing length, and the climbing length is in accordance with the relationship: 0.25 times the diameter of the rolling element≦ The climb length is 0.5 times the diameter of the rolling member. The first rotating section and the second rotating section form a rotating section, and the radius of the inner contour of the rotating section conforms to the relationship: 0.5 times the diameter of the rolling member, the radius of the inner contour, and the diameter of the rolling member. The first rotating section and the second rotating section are viewed from the axial direction, and the bottom contours of the first rotating section and the second rotating section are respectively formed by the first arc segment and the second arc segment being tangentially connected to each other. The first arc segment is different from the center of the second arc segment; and the length of the first arc segment conforms to the relationship: 0.5 times the length of the second arc segment < the length of the first arc segment < 0.8 times the length of the second arc segment; and the radius of the first arc segment is smaller than the radius of the second arc segment.

In the present invention, the reflow member is fixed to the mounting hole, and an annular fixing groove is recessed on the inner edge surface of the mounting hole. When the reflow member is provided with the mounting hole, the end surface of the reflow member is attached to the fixing groove. The inner groove wall is tangentially disposed, and a fixing member is disposed on the fixing groove, and the fixing member is in contact with the end surface of the returning member.

1‧‧‧ Splined shaft

11‧‧‧ rolling groove

2‧‧‧ Ontology

21‧‧‧Perforation

211‧‧‧ rolling groove

22‧‧‧Installation holes

23‧‧‧fixed slot

231‧‧‧Inside groove wall

24‧‧‧Return hole

3‧‧‧Return parts

31‧‧‧Return

32‧‧‧ end face

A‧‧‧ climbing section

B‧‧‧First turn

C‧‧‧second turn

D‧‧‧Connecting section

B1‧‧‧Bottom contour of the first turn

C1‧‧‧ bottom profile of the second turn

Q‧‧‧ tangent point

T‧‧‧Roller turning path

Radius of the first arc segment of R1‧‧

R2‧‧‧ radius of the second arc segment

Contour radius of the R3‧‧‧ revolving section

U‧‧‧The width of the return channel

H‧‧‧Climb height

C‧‧‧Climb length

90‧‧‧Load path

100‧‧‧Circular path

X‧‧‧axis direction

4‧‧‧Rolling parts

5‧‧‧Fixed parts

D1‧‧‧ diameter of perforation

D2‧‧‧ diameter of mounting hole

B2, C2‧‧‧ Center

The first figure is a system diagram of the linear drive ball spline device of the present invention.

The second figure is a combination view of the linear drive ball spline device of the present invention.

The third figure is a cross-sectional view of the second diagram A-A.

The fourth figure is a perspective view of the reflow member of the linear drive ball spline device of the present invention.

The fifth figure is a schematic diagram of the path of the return path of the reflow member of the present invention.

The sixth figure is a schematic diagram of the path of the return path of the reflow member of the present invention, which is viewed from the axial direction.

The seventh drawing is a cross-sectional view of the fifth drawing B-B, which illustrates the design of the climbing section of the return path.

1 to 3 are a preferred embodiment of the present invention. The present invention is a linear drive ball spline device comprising: a spline shaft (1) extending in one direction to a long length. a strip structure defining the extending direction as an axial direction (X), the surface of the spline shaft (1) is provided with a plurality of rolling grooves (11) extending along the axial direction (X); a moving body comprising the body (2), two reflow members (3) and a plurality of rolling members (4), the body (2) is provided with a perforation (21) for the spline shaft (1), the inner edge of the perforation (21) The surface is provided with a rolling groove (211) opposite to the rolling groove (11). The rolling groove (11) and the rolling groove (211) form a load path (90), and one end of the through hole (21) is respectively provided with a a mounting hole (22) having a diameter (D2) larger than a diameter (D1) of the through hole (21) and communicating with each other, the body (2) being further provided with a number relative to the rolling groove (211) And parallel to the rolling groove (211) a return hole (24) is disposed, and both ends of the return hole (24) are in communication with the mounting hole (22), and the return hole (24) has a circular cross section, that is, the return hole (24) The radial direction is a closed state; the two returning members (3) are respectively accommodated in the two mounting holes (22), and the returning member (3) is provided with a return passage (31) opposite to the rolling groove (211). The return channel (31) has a U-shaped profile, and its two ends are respectively coupled to the load path (90) and the return hole (24) to form a circulation path (100); the plurality of rolling elements (4) The system is set in the loop path (100).

In this embodiment, in order to fix the reflow member (3), an annular fixing groove (23) is recessed on the inner edge surface of the mounting hole (22), and when the reflow member (3) is provided with the mounting hole (22) The end surface (32) of the reflow member (3) is disposed tangentially to the inner groove wall (231) of the fixing groove (23), and is disposed on the fixing groove (23) by a fixing member (5). The fixing member (5) is in contact with the end surface (32) of the reflow member (3) to limit the axial direction (X) degree of freedom of the reflow member (3), and the fixing member (5) is in the embodiment The C-shaped buckle made of metal, whereby the reflowing member (3) is covered by a metal material in any direction, please cooperate with the second and third figures, the reflowing member (3) The radial direction is covered by the mounting hole (22), and one end of the axial direction (X) of the reflow member (3) is partially covered by the fixing member (5), and the covering range thereof exceeds the One-half of the end face (32) is optimal, and the other end is disposed facing the perforation (21), so that the ball spline device can be prevented from being impacted by the rolling member (4) due to improper use and the like (31). When the force is too large, the reflow member (3) is broken and damaged. : Because most of the reflow parts are made by plastic injection molding, it can be avoided because there is metal blocking around the reflow part (3). When the rolling member (4) falls out of the return passage (31), the device for mounting the ball spline device can be avoided, because the rolling member (4) completely disengages from the body (2) and the spline shaft (1), so that the device is lost. The originally limited degree of freedom causes the related components of the device to collide with each other and is damaged. Therefore, the present invention has the special fixing structure of the reflowing member (3), thereby having the safety effect of actively preventing the explosion of the bead (referring to the rolling member). Avoid bigger damage.

Furthermore, referring to the third to seventh figures, in order to obtain better smoothness when the rolling element (4) is operated in the circulation path (100), the present invention distinguishes the return path (31). For the fourth section, the four sections are sequentially connected to the climbing section (A), the first turning section (B), the second turning section (C) and the connecting section (D), wherein the climbing section (A) is The load path (90) is engaged, and the connecting section (D) is engaged with the return hole (24); as shown in the seventh figure, the climbing section (A) is partially accommodated in the rolling groove (11), and the climbing Segment (A) has a climb height (H) and a climb length (C), the climb height (H) is less than the climb length (C), and the climb length (C) conforms to the relationship: 0.25 times rolling The diameter of the piece ≦ the climbing length (C) ≦ 0.5 times the diameter of the rolling piece; the first turning section (B) and the second turning section (C) form a turning section, the radius of the contour of the turning section (R3) It is in accordance with this relationship: 0.5 times the diameter of the rolling member, the radius of the inner contour (R3), the diameter of the rolling member, and the width (U) of the return passage (31) is larger than the diameter of the rolling member (4).

Referring to the sixth figure, the first turning section (B) and the second turning section (C) are viewed from the axial direction (X), and the bottom sections of the first turning section (B) and the second turning section (C) The first arc segment (B1) and the second arc segment (C1) are respectively tangentially connected to each other, and have a tangent point (Q), and the first arc segment (B1) ) is different from the center (B2, C2) of the second circular arc segment (C1), and the length of the first circular arc segment (B1) conforms to the relationship: 0.5 times the second circular arc segment (C1) Length < Length of the first arc segment (B1) <0.8 times the length of the second arc segment (C1) [Note: The rolling member (4) continues to climb in the previous segment of the first segment (B), so The length of the first circular arc segment (B1) must be greater than the length of the second circular arc segment (C1) in order to make the climbing portion of the first rotating segment (B) relatively gentle, and let the rolling member (4) smoothly run to The second turning section (C) obtains a smoother rolling path (T) of the rolling element (4), and the radius (R1) of the first circular section (B1) is smaller than the second circular section ( C1) radius (R2); and the present invention is designed by the above-mentioned path, in particular, the design of the climbing height required when the rolling element (4) is detached from the rolling groove (11), and the creeping height is dispersed to the climbing section ( A) and the first section of the first turning section (B) (the definition of the preceding paragraph: from the junction of the climbing section and the first turning section to less than one-half of the total length of the first turning section), let the rolling elements ( 4) The climbing height of the climbing section (A) is higher than in the past Low gauge, also reducing its relative resistance to climbing, the rolling elements (4) run out smoothly while rolling groove (11).

In view of the above, the "industrial availability" of the present invention should be unquestionable. In addition, the feature technology disclosed in the embodiment of the present invention has not been seen in publications before the application, nor has it been disclosed. The use of not only has the fact that the effect is improved as described above, but also has an additional effect that cannot be neglected. Therefore, the "novelty" and "progressiveness" of the present invention are in compliance with the patent regulations, and the application for the invention patent is filed according to law. Please give us a review and grant a patent as soon as possible.

The above description of the embodiments is intended to be illustrative of the invention and is not intended to limit the invention. category.

1‧‧‧ Splined shaft

11‧‧‧ rolling groove

2‧‧‧ Ontology

21‧‧‧Perforation

211‧‧‧ rolling groove

22‧‧‧Installation holes

23‧‧‧fixed slot

231‧‧‧Inside groove wall

24‧‧‧Return hole

3‧‧‧Return parts

31‧‧‧Return

32‧‧‧ end face

90‧‧‧Load path

100‧‧‧Circular path

X‧‧‧axis direction

4‧‧‧Rolling parts

5‧‧‧Fixed parts

A‧‧‧ climbing section

D1‧‧‧ diameter of perforation

D2‧‧‧ diameter of mounting hole

Claims (2)

A linear drive ball spline device comprises: a spline shaft extending in a direction into an elongated structure defining an extension direction as an axial direction, the surface of the spline shaft being provided with a plurality of strips extending along an axial direction a rolling groove; a moving body comprising a body, two reflow members and a plurality of rolling elements, the system is provided with a perforation for the spline shaft, and the inner edge surface of the perforation is provided with a rolling groove opposite to the rolling groove, The rolling groove and the rolling groove form a load path, and the two ends of the hole are respectively provided with a mounting hole, the diameter of the mounting hole is larger than the diameter of the hole and the two are connected to each other, and the body is further provided with the quantity relative to the rolling a groove and a return hole disposed parallel to the rolling groove, the two ends of the return hole are connected to the mounting hole, and the cross hole has a circular cross section; the two reflow members are respectively accommodated in the mounting hole The reflow member is provided with a number of return passages opposite to the rolling groove, and the return passage contour is a U-shaped shape, and the two ends of the reflow passage are respectively connected with the load path and the return hole to form a circulation path; the plurality of rolling elements are Setting On the loop path Wherein, the return channel is divided into four segments, and the four segments are sequentially connected to the climbing segment, the first rotating segment, the second rotating segment and the connecting segment; the width of the returning channel is greater than the diameter of the rolling member; wherein The climbing section is partially accommodated in the rolling groove, the climbing section has a climbing height and a climbing length, the climbing height is less than the climbing length, and the climbing length is in accordance with the relationship: 0.25 times the diameter of the rolling piece, the climb The length ≦ 0.5 times the diameter of the rolling member; wherein the first rotating segment and the second rotating segment form a rotating segment, and the radius of the inner contour of the rotating segment conforms to the relationship: 0.5 times the diameter of the rolling member The radius ≦ the diameter of the rolling member; wherein the first rotating segment and the second rotating segment are viewed by the axial direction, and the bottom profiles of the first rotating segment and the second rotating segment are respectively formed by the first circular segment and the second The arc segments are connected to each other tangentially, and the first arc segment is different from the center of the second arc segment; and the length of the first arc segment conforms to the relationship: 0.5 times the second arc segment Length < length of the first arc segment <0.8 The length of the second arc segment; and the radius of the first arc segment is smaller than the radius of the second arc segment. The linear drive ball spline device of claim 1, wherein an inner annular surface of the mounting hole is recessed and provided with an annular fixing groove, and when the returning member is provided with the mounting hole, an end surface of the returning member is coupled to the fixing groove The inner groove wall is tangentially disposed, and a fixing member is disposed on the fixing groove, and the fixing member is in contact with the end surface of the returning member.