JP6032028B2 - Linear motion guide device - Google Patents

Description

  The present invention relates to a linear motion guide device.

  For example, in a linear motion table device incorporated in a machine tool, a semiconductor manufacturing apparatus or the like, one ball screw is used, and a structure in which the ball screw is rotationally driven by one motor is widely used. In order to increase the moving speed of the table in such a linear motion table device, a technique of increasing the lead of the ball screw, a technique of improving the rotational speed of the motor, or the like is taken.

  On the other hand, Patent Documents 1 and 2 disclose a ball screw unit in which two screw grooves are provided at an interval in the axial direction with respect to one screw shaft, and a nut is screwed into each screw groove. ing. In these ball screw units, speed-up feeding is realized by setting the winding directions of the two screw grooves to opposite directions. Further, Patent Document 1 also discloses that a reduced speed feed is possible by setting the winding direction of two screw grooves to the same direction.

JP 58-113653 A JP-A-4-73450

However, in the ball screw units disclosed in Patent Documents 1 and 2, since two screw grooves are provided at an interval in the axial direction with respect to one screw shaft, the screw shaft becomes long, and as a result. Also, the axial length of the ball screw unit becomes longer. Therefore, the linear motion table device incorporating such a ball screw unit has a problem that the overall length of the device is long.
SUMMARY OF THE INVENTION Accordingly, the present invention provides a linear motion guide device that solves the above-described problems of the prior art and enables speed-up feed or speed-down feed while avoiding an increase in axial length. Let it be an issue.

  In order to solve the above problems, an aspect of the present invention has the following configuration. That is, the linear motion guide device according to one aspect of the present invention is a linear motion guide device including two ball screws arranged in parallel, and is attached to the base so as to be rotatable and axially immovable. A first screw shaft having a spiral screw groove and a linear spline extending along the axial direction formed on the outer peripheral surface; and a screw groove facing the screw groove of the first screw shaft on the inner peripheral surface. The first screw is movable in the axial direction through rolling of a plurality of first balls arranged in a spiral ball rolling path formed by the screw groove and the screw groove of the first screw shaft. A first nut attached to the shaft, and coaxially arranged with the first nut, and is attached to the first screw shaft so as to be rotatable integrally with the first screw shaft and guided by the spline and movable in the axial direction. A first ball screw comprising a cylindrical member, and a base A second screw shaft that is rotatably and axially movable and has a helical screw groove formed on the outer peripheral surface, and a screw groove that faces the screw groove of the second screw shaft on the inner peripheral surface. And a plurality of second balls arranged in a spiral ball rolling path formed by the thread groove and the thread groove of the second screw shaft so as to be relatively movable in the axial direction. A second ball screw having a second nut attached to the second screw shaft; a rotation transmission mechanism for transmitting rotation of the cylindrical member to the second screw shaft; and the first nut and the second screw. A first connecting member that connects the first nut and the second screw shaft such that the shaft is integral and movable in the axial direction, and the first nut is not rotatable and the second screw shaft is rotatable; The cylindrical member and the second screw shaft are integrally movable and Serial cylindrical member and the second screw shaft, characterized in that it and a second connecting member for connecting the second screw shaft and the cylindrical member so as to be rotatable.

  In this linear motion guide device, the axial range in which the thread groove in the first screw shaft is formed and the axial range in which the spline is formed may overlap at least partially. Moreover, the axial direction range in which the thread groove in the first screw shaft is formed may not overlap with the axial range in which the spline is formed.

  The linear motion guide device according to the present invention is capable of speed-up feed or speed-down feed while avoiding an increase in length in the axial direction.

It is a side view explaining the structure of the linear motion table apparatus which is 1st embodiment of the linear motion guide apparatus which concerns on this invention. It is a side view explaining the structure of the linear motion table apparatus which is 2nd embodiment of the linear motion guide apparatus which concerns on this invention.

  An embodiment of a linear motion guide device according to the present invention will be described in detail with reference to the drawings.

[First embodiment]
FIG. 1 is a side view for explaining the structure of a linear motion table device that is a first embodiment of the linear motion guide device according to the present invention (however, an outer ring equivalent member 15, a nut housing 51, and a table 55 to be described later). Is shown in cross section).
The linear motion table device of FIG. 1 includes two ball screws (a first ball screw 10 and a second ball screw 20) arranged in parallel. That is, the first ball screw 10 and the second ball screw 20 are arranged with the screw shafts 11 and 21 parallel to each other.

  A first ball screw 10 shown on the lower side in FIG. 1 includes a first screw shaft 11 having a spiral thread groove 11a and a linear spline 11b extending along the axial direction formed on the outer peripheral surface, A first nut 12 having a thread groove (not shown) opposed to the thread groove 11a of the one screw shaft 11 formed on the inner peripheral surface, a thread groove 11a of the first screw shaft 11 and a thread groove of the first nut 12; A plurality of first balls (not shown) arranged in a freely rolling manner in a spiral ball rolling path (not shown) formed by, and circulating the first ball from the end point of the ball rolling path to the starting point A circulating portion (not shown) to be rotated, and a cylindrical member 13 attached to the first screw shaft 11 so as to be rotatable integrally with the first screw shaft 11 and guided in the spline 11b so as to be movable in the axial direction. ing.

  The spline 11b of the first screw shaft 11 is formed so as to intersect with the spiral thread groove 11a. That is, the axial direction range in which the thread groove 11a is formed in the first screw shaft 11 and the axial direction range in which the spline 11b is formed partially overlap, for example, one end side of the first screw shaft 11 (FIG. 1). In FIG. 1, only the spline 11b is formed in the axial range on the right end side, and only the screw groove 11a is formed in the axial range on the other end side (left end side in FIG. 1). Both screw grooves 11a are formed to overlap each other. The number of splines 11b is not particularly limited, and may be one or plural, but may be three, for example.

  The first screw shaft 11 is fixed to wall bodies 31, 31 provided perpendicular to the base 30 so as to be parallel to the surface of the base 30. That is, both end portions of the first screw shaft 11 are rotatable on two wall bodies 31, 31 provided on the base 30 via bearings (not shown) such as a rolling bearing and a sliding bearing, respectively, and in the axial direction. It is immovably attached to. Since the rotational driving force is supplied from the rotational driving source 40 such as a motor to, for example, one end (right end in FIG. 1) of the first screw shaft 11, the first screw shaft 11 has two walls. The body 31 is supported by the body 31 and rotates without moving in the axial direction.

  The first screw shaft 11 is inserted through the first nut 12 and the cylindrical member 13, and the first nut 12 and the cylindrical member 13 are arranged coaxially along the axial direction. The first nut 12 is screwed to the first screw shaft 11 by the first ball, and when the first screw shaft 11 rotates, the first nut 12 moves in the axial direction through rolling of the first ball. . The first nut 12 is non-rotatably fixed to a nut housing 51 (corresponding to the first connecting member according to the configuration of the present invention) mounted on the base 30 so as to be movable in the axial direction. Therefore, when the first screw shaft 11 rotates, the first nut 12 does not rotate but moves in the axial direction together with the nut housing 51. The moving direction of the first nut 12 is determined by the winding direction (right screw or left screw) of the first ball screw 10, and the moving amount per rotation of the first nut 12 relative to the first screw shaft 11. Is determined by the lead of the first ball screw 10.

  The cylindrical member 13 is attached to the first screw shaft 11 so as to be rotatable integrally with the first screw shaft 11 and to be movable in the axial direction guided by the spline 11b. More specifically, for example, a ball spline structure is provided between the cylindrical member 13 and the first screw shaft 11. A linear spline (not shown) facing the spline 11b of the first screw shaft 11 is formed on the inner peripheral surface of the cylindrical member 13, and a plurality of splines interposed between the two splines are formed. A cylindrical member 13 is fixed to the first screw shaft 11 so as to be rotatable integrally with the first screw shaft 11 via a ball (not shown), and a cylinder is formed by rolling a plurality of spline balls. The shaped member 13 is guided by the spline 11b of the first screw shaft 11 and is movable in the axial direction.

  However, since the spline 11b of the first screw shaft 11 is formed so as to intersect with the spiral thread groove 11a, the first ball moves out of the ball rolling path and moves between both splines at this intersection. The spline ball must be structured so that it does not move between the splines and move to the ball rolling path. If there is a difference in the groove depth between both screw grooves of the first ball screw 10 and both splines, the ball may move to the deeper groove, so the groove depth and the ball diameter may be the same, or the spline ball It is preferable to prevent the ball from moving as described above by using a cage that holds the ball.

In place of the spline balls, it is also possible to use a key that is fitted into the spline 11b of the first screw shaft 11 and the spline on the inner peripheral surface of the cylindrical member 13. When a key is used, the cylindrical member 13 is fixed to the first screw shaft 11 so as to be rotatable integrally with the first screw shaft 11 via a plurality of keys fitted in both splines, The cylindrical member 13 is guided by the spline 11b of the first screw shaft 11 through the sliding of the key and is movable in the axial direction.
The cylindrical member 13 corresponds to a nut housing 51 (corresponding to the second connecting member according to the configuration of the present invention via a support bearing such as a rolling bearing and a sliding bearing, and in the present embodiment, the first connecting member. And the second connecting member are the same member, except that the first connecting member and the second connecting member may be separate members.

  The configuration of the support bearing can be exemplified as follows. A cylindrical member 15 corresponding to the outer ring of the bearing is coaxially arranged on the outer side in the radial direction of the cylindrical member 13, and between the outer ring equivalent member 15 and the cylindrical member 13 which is a member corresponding to the inner ring. A rolling element 17 is arranged so as to freely roll. The outer ring equivalent member 15, the cylindrical member 13, and the rolling element 17 constitute a support bearing. In FIG. 1, balls are shown as the rolling elements 17, but rollers may be used. Or it is good also considering a support bearing as a slide bearing, without using a rolling element.

  When the first screw shaft 11 rotates, the first nut 12 moves in the axial direction, and accordingly, the nut housing 51 moves in the axial direction. However, the outer ring equivalent member 15 cannot rotate to the nut housing 51. Since it is fixed, the outer ring equivalent member 15 and the cylindrical member 13 also move in the axial direction together with the first nut 12 and the nut housing 51. In this case, since the cylindrical member 13 is attached to the first screw shaft 11 so as to be rotatable integrally with the first screw shaft 11, the outer ring equivalent member 15 does not rotate, but the cylindrical member 13 is supported. It rotates integrally with the first screw shaft 11 while being supported by the bearing.

  Next, the second ball screw 20 illustrated on the upper side in FIG. 1 is opposed to the second screw shaft 21 in which a spiral screw groove 21a is formed on the outer peripheral surface and the screw groove 21a of the second screw shaft 21. A spiral ball rolling path formed by a second nut 22 having a thread groove (not shown) formed on the inner peripheral surface, a thread groove 21a of the second screw shaft 21, and a thread groove of the second nut 22. A plurality of second balls (not shown) arranged in a freely rollable manner (not shown), and a circulation part (not shown) for circulating the second balls from the end point of the ball rolling path back to the starting point; It has.

  One end portion (right end portion in FIG. 1) of the second screw shaft 21 is rotatably attached to the nut housing 51 via a bearing (not shown) such as a rolling bearing or a sliding bearing. Therefore, the second screw shaft 21 is connected to the first nut 12 and the cylindrical member 13 via the nut housing 51. Further, the other end (the left end in FIG. 1) is attached to a second screw shaft support member 53 mounted on the base 30 so as to be movable in the axial direction, for example, a bearing such as a rolling bearing or a slide bearing (not shown). Z)). And the rotation transmission mechanism 60 which transmits the rotation of the cylindrical member 13 to the 2nd screw shaft 21 is provided, and a rotational drive force is supplied to the one end part of the 2nd screw shaft 21 by the rotation transmission mechanism 60, for example. Therefore, the second screw shaft 21 rotates with the rotation of the cylindrical member 13 (first screw shaft 11).

  Although the kind of rotation transmission mechanism 60 is not specifically limited, For example, a belt and a gear are mention | raise | lifted. When the belt 61 is used as shown in FIG. 1, pulleys are formed on the outer peripheral surface of the cylindrical member 13 and the outer peripheral surface of one end of the second screw shaft 21, and the endless belt 61 is hung around both pulleys. For example, the rotation of the cylindrical member 13 (first screw shaft 11) is transmitted to the second screw shaft 21. In this case, the rotation direction of the cylindrical member 13 (first screw shaft 11) and the rotation direction of the second screw shaft 21 are the same direction. When gears are used, gears are formed on the outer peripheral surface of the cylindrical member 13 and the outer peripheral surface of one end portion of the second screw shaft 21, respectively. ) Is transmitted to the second screw shaft 21. In this case, the rotation direction of the cylindrical member 13 (first screw shaft 11) and the rotation direction of the second screw shaft 21 are opposite to each other.

  Since the second screw shaft 21 is attached to the nut housing 51, the second screw shaft 21 moves in the same direction together with the second screw shaft support member 53 as the nut housing 51 moves in the axial direction. To do. Further, since the second nut 22 is screwed to the second screw shaft 21 by the second ball, when the second screw shaft 21 rotates, the second nut 22 is moved with respect to the second screw shaft 21 through the rolling of the second ball. It moves relative to the axial direction.

  And since the 2nd nut 22 is being fixed to the table 55 mounted on the base 30 so that the movement to an axial direction was non-rotatable, when the 2nd screw shaft 21 rotates, the 2nd nut 22 moves in the axial direction without rotating, and moves the table 55 in the axial direction. The moving direction of the second nut 22 is determined by the winding direction (right screw or left screw) of the second ball screw 20, and the moving amount per rotation of the second nut 22 relative to the second screw shaft 21. Is determined by the lead of the second ball screw 20.

  As described above, when the first screw shaft 11 is rotated by the rotational drive source 40, the first nut 12, the cylindrical member 13, and the second screw shaft 21 are integrally moved via the nut housing 51 in the axial direction. In addition, since the rotation is transmitted from the first screw shaft 11 to the second screw shaft 21 by the rotation transmission mechanism 60, the rotation of the second screw shaft 21 causes the second nut 22 to move in the axial direction with respect to the second screw shaft 21. Move relative to. Therefore, an article or the like placed on the table 55 can be sent to a desired position.

  At this time, the speed-up feed or the speed-down feed can be realized by a combination of the winding direction of the ball screws 10 and 20 and the rotation direction of the screw shafts 11 and 21 (that is, the type of the rotation transmission mechanism 60). it can. In the case where the winding directions of the first ball screw 10 and the second ball screw 20 are the same direction, if the rotation directions of both screw shafts 11 and 21 are the same direction, the speed-up feed is performed. If the direction of rotation is the opposite direction, the speed will be reduced.

  More specifically, when the first screw shaft 11 is rotated, the first nut 12, the cylindrical member 13, and the second screw shaft 21 are integrally moved through the nut housing 51 and moved in the axial direction. The rotation of the screw shaft 21 causes the second nut 22 to move relative to the second screw shaft 21 in the axial direction. At this time, if the rotational directions of both screw shafts 11 and 21 are the same, the moving direction of the second nut 22 is the same as the first nut 12, the cylindrical member 13, and the second screw shaft 21. Accordingly, the moving speed of the second nut 22 is the sum of the relative moving speed of the second nut 22 with respect to the second screw shaft 21 and the moving speed of the second screw shaft 21 (first nut 12). It becomes larger than the moving speed of the table of a general linear motion table device provided with a ball screw (accelerated feed). For example, when the lead of the first ball screw 10 and the second ball screw 20 are the same and the gear ratio of the pulley is 1, the moving speed is twice the moving speed of the table of a general linear motion table device. The table 55 can be sent at (double speed). Of course, the leads of the first ball screw 10 and the second ball screw 20 may be the same or different, and the gear ratio of the pulley may be 1 or not 1. Of course, it may be.

  When the rotational directions of the screw shafts 11 and 21 are opposite directions, the moving direction of the second nut 22 is opposite to the first nut 12, the cylindrical member 13, and the second screw shaft 21. Accordingly, the moving speed of the second nut 22 is the difference between the relative moving speed of the second nut 22 with respect to the second screw shaft 21 and the moving speed of the second screw shaft 21 (first nut 12). It becomes smaller than the moving speed of the table of a general linear motion table device having a ball screw (decelerated feed).

On the other hand, when the winding directions of the first ball screw 10 and the second ball screw 20 are opposite directions, the speed increases when the rotation directions of the screw shafts 11 and 21 are opposite directions by the same mechanism as described above. When the rotational directions of both screw shafts 11 and 21 are the same, the feed is reduced.
In the linear motion table device of FIG. 1, the winding directions of the first ball screw 10 and the second ball screw 20 are the same direction, and the rotational directions of both screw shafts 11 and 21 are the same direction using the belt 61 and the pulley. It is an example of the linear motion table device of the increased speed feed.

  Since the linear motion table device of FIG. 1 has two ball screws 10 and 20 arranged in parallel, two screw grooves are provided at an axial interval with respect to one screw shaft (that is, Compared with the ball screw units of Patent Documents 1 and 2 (two ball screw mechanisms are arranged in series), the overall length of the device is short, and is almost the same as that of a general linear motion table device having one ball screw. It is possible to make the entire length of the apparatus, and speed-up feeding is possible while avoiding an increase in the axial length.

  1 includes the cylindrical member 13 that is guided by the spline 11b of the first screw shaft 11 and is movable in the axial direction, so that the rotational drive source 40 such as a motor does not move. It can be set as the structure fixed to the base 30. FIG. Therefore, in the case of a structure in which the rotation drive source moves when the ball screw is driven, there is a problem that a cable for supplying electricity to the rotation drive source is dragged. There is no problem with cables being dragged.

  Furthermore, in a general method of using a ball screw, a rotational drive source such as a motor that rotates the screw shaft is arranged coaxially with the screw shaft. The linear motion table device of this embodiment is disclosed in Patent Document 2. Unlike the disclosed ball screw unit, the rotational drive source 40 moves even when the rotational drive source 40 is arranged coaxially with the first screw shaft 11 by employing the above general method of using the ball screw. It has the merit that it can be set as the structure which does not.

Further, since the belt 61 and the pulley are employed in the rotation transmission mechanism 60 and the rotation directions of the screw shafts 11 and 21 are the same, the winding directions of the first ball screw 10 and the second ball screw 20 are the same. It can be. When the winding directions of the two ball screws 10 and 20 are opposite directions, a left-handed screw shaft that is difficult to obtain is necessary. A moving table device can be manufactured. In addition, if a gear is used for the rotation transmission mechanism 60 and the rotation directions of both screw shafts 11 and 21 are opposite directions, the winding directions of the two ball screws 10 and 20 can be the same direction. There is a risk of problems resulting from gear backlash.
Furthermore, since the linear motion table device of FIG. 1 can perform high-speed feeding without increasing the rotational speed of the rotational drive source 40 such as a motor, it is possible to avoid the critical speed of the screw shaft.

[Second Embodiment]
FIG. 2 is a side view for explaining the structure of a linear motion table device that is a second embodiment of the linear motion guide device according to the present invention (however, an outer ring equivalent member 15, a nut housing 51, a second screw shaft support member). 53 and the table 55 are shown in cross section). In addition, since the structure of the linear motion table apparatus of 2nd embodiment, an effect | action, and an effect are substantially the same as 1st embodiment, only a different part is demonstrated and description of the same part is abbreviate | omitted. Further, in FIG. 2, the same reference numerals as those in FIG.

  As shown in FIG. 2, the spline 11b of the first screw shaft 11 is formed so as not to intersect the spiral thread groove 11a. That is, the axial range in which the screw groove 11a is formed in the first screw shaft 11 and the axial range in which the spline 11b is formed do not overlap. For example, one end side of the first screw shaft 11 (in FIG. 1) Only the screw groove 11a is formed in the axial range on the right end side, and only the spline 11b is formed in the axial range on the other end side (left end side in FIG. 1).

  In the first embodiment, the first connecting member and the second connecting member are the same member. However, in the second embodiment, the first nut 12 and the cylindrical member 13 are spaced apart in the axial direction. Therefore, it is a separate member. That is, the first nut 12 is non-rotatably fixed to the nut housing 51 that is the first connecting member, and the cylindrical member 13 is attached to the second screw shaft support member 53 that is the second connecting member. It is rotatably mounted via a support bearing having a configuration similar to that of the embodiment.

  Since the second screw shaft 21 is rotatably attached to the nut housing 51 via a bearing (not shown) such as a rolling bearing or a slide bearing, the first nut 12 and the second screw shaft 21 are connected to the nut housing. 51 are connected via a single shaft 51, and can be moved in the axial direction integrally. In addition, since the second screw shaft 21 is rotatably attached to the second screw shaft support member 53 via a bearing (not shown) such as a rolling bearing or a sliding bearing, the second screw shaft support member 53 and the second screw shaft support member 53 are provided. The screw shaft 21 is connected via a second screw shaft support member 53, and is integrally movable in the axial direction.

  When the first screw shaft 11 is rotated by the rotational drive source 40, the first nut 12 and the second screw shaft 21 move together in the axial direction via the nut housing 51, and the second screw shaft 21 moves in the axial direction. Therefore, the cylindrical member 13 moves in the axial direction integrally with the second screw shaft 21 via the second screw shaft support member 53. That is, the first nut 12, the cylindrical member 13, and the second screw shaft 21 are integrally moved in the same direction. Further, since the rotation is transmitted from the first screw shaft 11 to the second screw shaft 21 by the rotation transmission mechanism 60, the rotation of the second screw shaft 21 causes the second nut 22 to move in the axial direction with respect to the second screw shaft 21. Move relative. Therefore, an article or the like placed on the table 55 can be sent to a desired position.

  As described above, since the spline 11b of the first screw shaft 11 and the screw groove 11a are formed so as not to overlap with each other, the first nut 12 is within the axial range of approximately one end side of the first screw shaft 11. Is moved in the axial direction, and the cylindrical member 13 moves in the axial direction within the axial direction range of approximately half of the other end side of the first screw shaft 11. From such a configuration, the length of the first screw shaft 11 is slightly longer than that of the first embodiment, but compared with the ball screw unit of Patent Documents 1 and 2 in which two ball screw mechanisms are arranged in series. The overall length of the apparatus is short, and speed-up feeding is possible while avoiding an increase in the axial length.

  Further, since the spline 11b of the first screw shaft 11 and the spiral thread groove 11a do not intersect, the countermeasures required in the linear motion table device of the first embodiment, that is, the groove depth and the ball diameter are the same. It is not necessary to take measures to prevent the movement of the balls by using a cage for holding the spline balls. Therefore, in the linear motion table device of the second embodiment, the specifications of the first ball screw 10 (the first screw shaft 11 and the first nut 12) are not restricted, and the degree of design freedom is large.

In addition, 1st and 2nd embodiment showed an example of this invention, Comprising: This invention is not limited to 1st and 2nd embodiment. For example, the type of belt 61 used in the rotation transmission mechanism 60 is not particularly limited, and a timing belt, a flat belt, a V belt, a round belt, a toothed belt, or the like can be used.
Further, by further setting the gear ratio of the pulley used in the rotation transmission mechanism 60, further speed-up feed and speed-down feed can be performed.

Furthermore, in this embodiment, the linear motion table apparatus provided with two ball screws was illustrated, but you may provide three or more ball screws.
Furthermore, the circulation system of the circulation unit is not particularly limited, and a conventional system such as a top type, a tube type, an end cap type, an end deflector type, or the like can be used.

DESCRIPTION OF SYMBOLS 10 1st ball screw 11 1st screw shaft 11a Thread groove 11b Spline 12 1st nut 13 Cylindrical member 20 2nd ball screw 21 2nd screw shaft 21a Thread groove 22 2nd nut 30 Base 40 Rotation drive source 51 Nut housing 53 Second screw shaft support member 55 Table 60 Rotation transmission mechanism 61 Belt

Claims (3)

A linear motion guide device comprising two ball screws arranged in parallel,
A first screw shaft which is attached to a base so as to be rotatable and immovable in an axial direction, and has a helical thread groove and a linear spline extending along the axial direction formed on an outer peripheral surface; A plurality of first balls having a screw groove facing the screw groove of the shaft on the inner peripheral surface and arranged in a spiral ball rolling path formed by the screw groove and the screw groove of the first screw shaft A first nut that is attached to the first screw shaft so as to be movable in the axial direction via rolling, and is arranged coaxially with the first nut, is rotatable integrally with the first screw shaft, and is connected to the spline. A first ball screw comprising: a cylindrical member that is guided and attached to the first screw shaft so as to be movable in the axial direction;
A second screw shaft that is rotatably and axially movable with respect to the base and has a helical screw groove formed on the outer peripheral surface, and a screw groove that is opposed to the screw groove of the second screw shaft. Relative movement in the axial direction through rolling of a plurality of second balls arranged in a spiral ball rolling path formed on the peripheral surface and formed by this thread groove and the thread groove of the second screw shaft A second nut screw, possibly attached to the second screw shaft;
A rotation transmission mechanism for transmitting rotation of the cylindrical member to the second screw shaft;
The first nut and the second screw shaft are configured such that the first nut and the second screw shaft are integrally movable and can move in the axial direction, and the first nut is not rotatable and the second screw shaft is rotatable. A first connecting member for connecting
The cylindrical member and the second screw shaft are connected to each other so that the cylindrical member and the second screw shaft can move in an axial direction and the cylindrical member and the second screw shaft can rotate. A second connecting member,
A linear motion guide device comprising:   The linear motion guide according to claim 1, wherein an axial range in which the thread groove is formed in the first screw shaft and an axial range in which the spline is formed overlap at least partially. apparatus.   2. The linear motion guide device according to claim 1, wherein an axial range in which the screw groove is formed in the first screw shaft does not overlap an axial range in which the spline is formed.

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