JPH11108056A - Finite linear guide way and finite linear guide unit assembling it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a finite linear guide way and a finite linear guide unit assembling the guide way, which can control the movement of a track member securely by preventing the slippage of a holder. SOLUTION: In the track grooves 13 and 18 opposing between track members 3 and 4, plural cylindrical rollers 22 held in a holder 23 can be rotated. With the racks 24 fixed to escape grooves 16 and 21, pinions supported rotatable to the holder 23 are engaged. Since recesses 47 for avoiding the interference with the cylindrical rollers 22 are formed to the teeth 46 of the racks 24, the engaging strength of the teeth 46 with the pinions are enhanced by forming the tooth with a large module, and a slippage of the holder 23 to the track members 3 and 4 is prevented. And since the escape grooves 16 and 21 are not large, wide track surfaces 14, 15, 19, and 20 can be secured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a finite linear guideway in which a rolling element is interposed between a pair of track members having track grooves formed in a longitudinal side wall surface so that the track members move relative to each other. And a finite linear motion guide unit incorporating the same.

[0002]

2. Description of the Related Art Conventionally, a finite linear motion guideway is shown in FIG.
0, a pair of track members 3 and 4, which are set so as to be able to move relative to each other in parallel to each other, a retainer 23 disposed between the track members 3 and 4, and The raceway groove 13 of the raceway member 3 supported by the cage 23
And a plurality of cylindrical rollers 22 interposed between the raceway member 4 and the raceway groove 18. A substantially V-shaped raceway groove 13 in which an upper raceway surface 14, a lower raceway surface 15, and a relief groove 16 are formed is formed in the longitudinal side wall surface 12 of the raceway member 3. A substantially V-shaped raceway groove 18 having an upper raceway surface 19, a lower raceway surface 20, and a relief groove 21 is formed on the longitudinal side wall surface 17 of the raceway member 4. Also, screw holes 51 are formed in both end surfaces 50 of the track members 3 and 4, and end screws 10 as stoppers are screwed in to prevent the retainer 23 from dropping off.

In the above-mentioned finite linear guideway, the cage 23 is usually made of a metal material, and the holding holes 27 are formed at equal intervals. In order to hold the cylindrical roller 22 by the retainer 23, the cylindrical roller 22 is held by locking claws 29 formed on upper and lower portions of the edge of the holding hole 27 formed in the retainer 23.
Is locked. Further, the cylindrical rollers 22 are arranged in such a manner that adjacent ones cross the rotation axis.

[0004] In the above finite linear motion guideway,
The present applicant prevents the cage from being displaced from an appropriate position with respect to the raceway member even if the frequency of stroke of the raceway member is high and vibration or unequally distributed load or the like is encountered in use. A finite direct-acting guideway is provided which can ensure that the relative movement of the track member is always smooth without any risk of the retainer coming off the track member (see JP-A-7-91445). .

The finite direct-acting guideway disclosed in the above publication is composed of a pair of track members having track grooves formed in a longitudinal side wall surface, cylindrical rollers disposed in a track between the track grooves of each track member, And a finite direct-acting guideway having a plate-shaped retainer for holding a cylindrical roller disposed between track members, a rack disposed in a clearance groove formed in a track groove, and meshing with the rack. Further, it has a pinion rotatably mounted in a through hole formed in the retainer. When the pair of track members move relative to each other, the track member and the retainer also move relative to each other. At this time, the pinion moves while meshing with the rack. Therefore, since the raceway member does not slip with the cage, the movement can be reliably controlled, and the cage fitted with the cylindrical rollers does not come off from the end of the raceway member.

[0006]

The above-mentioned finite direct-acting guideway in which the rack provided in the relief groove and the pinion rotatably mounted on the retainer are engaged with each other, supports a large load. Even when used, the rack and the pinion can be securely engaged with each other without changing the size and structure of the relief groove, to prevent deviation from the raceway member of the cage and to maintain a wide raceway surface. There is a need for a finite linear guideway and a finite linear guide unit incorporating the same.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to prevent the interference between the teeth of the rack and the rolling elements, so that the teeth of the large module can be inserted into the teeth of the rack without changing the size or structure of the clearance groove. The rack and the pinion are used to increase the rigidity of the teeth, and the rack and the pinion are securely engaged with each other to prevent the cage from being displaced from the proper position with respect to the raceway member. An object of the present invention is to provide a finite linear guideway capable of preventing a reduction in load that can be supported and supported, and a finite linear guide unit incorporating the guideway.

According to the present invention, there is provided a pair of track members having track grooves formed in the side wall surface in the longitudinal direction, a plurality of cylindrical rollers provided in a track between the track grooves of each track member, and a plurality of track rollers disposed between the track members. A plate-shaped retainer for holding the cylindrical rollers provided, a rack disposed in a clearance groove formed in the track groove, and a mounting hole formed in the retainer which meshes with the rack and is rotatable. The racks are provided with recesses in order to prevent the cylindrical rollers rolling on the track from interfering with the teeth of the rack. It relates to a linear guideway.

Since the finite linear guideway according to the present invention is constructed as described above, when the pair of track members move relative to each other, the cylindrical rollers roll on the track between the track grooves. Even if it moves relative to the pair of track members together with the retainer, the tips of the cylindrical rollers only pass through the recesses formed in the teeth of the rack, and do not interfere with the teeth of the rack. Therefore, a large module tooth can be used for the rack and the pinion, and the engagement strength between the rack and the pinion increases. As a result, the retainer does not deviate from an appropriate position with respect to the track member even when a large force such as the cylindrical roller slides acts, and the relative movement of the pair of track members can be accurately controlled.

In this finite linear guideway, the depth of the recess of the rack is at most the depth to the reference pitch line of the teeth of the rack. Since the concave portion does not gouge the tooth greatly, the influence on the strength of the tooth can be minimized.

In this finite linear motion guideway, the cylindrical roller is held with its rotation axis inclined with respect to the plate surface of the cage, and the raceway groove of the raceway member is rotated by the rotation of the cylindrical roller. It has a raceway surface parallel to the axis, and the recess of the rack is substantially V-shaped so that the rolling cylindrical rollers can pass through it.
It is formed in a character shape. Since the cylindrical roller rolls with its rotation axis inclined, the corner that is the boundary between one end face of the cylindrical roller and the peripheral surface is closest to the rack, and such a corner is the tooth of the rack. The recess formed in each tooth of the rack is substantially V-shaped so as to avoid interference with the rack.

In this finite linear guideway, the rack is attached to the track member by being tightened between heads of end screws screwed to both end surfaces of the track member. The rack is attached to the track member by being sandwiched between both heads of end screws screwed to both end faces of the track member, so that the rack is not attached to the track member with an adhesive or the like. The work of attaching the rack to the track member is simplified.

[0013] In this finite linear guideway, the pinion comprises a pinion body having teeth and shaft portions formed integrally with the pinion body on both sides of the pinion body, and is locked by a retainer. The pinion is mounted on the holder via a gear holder composed of a pair of gear holders, and the shaft of the pinion is rotatably fitted into a hole formed in the gear holder. By forming the pinion into a structure in which the pinion body having teeth and the shaft are integrated, the rotation of the pinion is stabilized and the number of components is reduced.

Further, a finite linear motion guide unit is constituted by incorporating the above finite linear motion guideway. That is, the finite linear motion guide unit includes a pair of moving members that move relative to each other, and between the pair of moving members, the finite linear motion guideway attaches one track member to one moving member. It is incorporated with the other track member attached to the other moving member.

In the above-mentioned finite linear motion guide unit, the one moving member is a bed, and the one track member is mounted on the bed and has an intermediate track formed with track grooves on both longitudinal side walls. The other moving member is a movable member that straddles the intermediate track member on the bed, and the movable member has a pair of track grooves formed on the side wall surface in the longitudinal direction, each of the track members opposing the track groove of the intermediate track member. The other track member is attached.
In such a finite linear guide unit, the movable body as the other moving member is mounted on both sides of the intermediate track member with respect to the bed as the one moving member. , The cylinder roller rolls on a wide track surface without slipping, so that it moves stably.

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 1 is an end view showing one embodiment of a finite linear guide unit according to the present invention,
FIG. 2 is a plan view showing a cross section of a part including one finite linear guideway incorporated in the finite linear guide unit shown in FIG. 1, and FIG. 3 is a plan view of the finite linear guide unit shown in FIG. FIG. 4 is a partial cross-sectional view taken along the line AA, FIG. 4 is an enlarged cross-sectional view showing a part C of the finite linear motion guide unit shown in FIG.
FIG. 3 is a partial sectional view of the limited linear motion guide unit shown in FIG. In this embodiment, components having the same functions as those of the components used in the finite linear guideway shown in FIG. 20 are denoted by the same reference numerals.

First, an outline of a finite linear motion guide unit according to the present invention will be described with reference to FIGS. The limited linear motion guide unit includes a bed 1 positioned below and a movable body 2 such as a table guided on the bed 1. The bed 1 and the movable body 2 constitute a movable member that can move relative to each other. A track member 3 is placed at the upper center of the bed 1, and the track member 3 is fixed to the bed 1 by mounting bolts 5 inserted into bolt holes formed in the bed 1.
And an intermediate race member in which race grooves 13 (described later) are formed in the longitudinal side walls 12 on both sides. A cavity 7 is formed below the movable body 2, and the movable body 2 has a portal shape as a whole straddling the track member 3. The track member 3 attached to the bed 1 is accommodated in the space 7 of the movable body 2, and on both sides of the movable body 2,
A pair of track members 4 and 4 sandwich the track member 3 from both sides.
Are arranged. Each track member 4 is fixed to the movable body 2 by a mounting bolt 6 inserted into a bolt hole formed in the movable body 2. The bed 1 is provided with mounting bolts (not shown) inserted into bolt holes 8 formed in the bed 1.
To a machine base or other moving body (not shown). A work or another moving body (not shown) is attached to the moving body 2 by a mounting bolt (not shown) inserted into a screw hole 9 formed in the moving body 2. On both sides of each end face of the track member 3 and on each end face of each track member 4,
An end screw 10 for preventing the retainer 23 from dropping is screwed. Between the race member 3 and the pair of race members 4, a finite direct-acting guideway 11 having a plurality of cylindrical rollers 22 as rolling elements and a retainer 23 for holding the cylindrical rollers 22 is provided. ing.

Next, referring to FIGS.
Each finite direct-acting guideway 11 provided between the pair of track members 4 and 4 will be described. As shown in FIGS. 3 and 5, a substantially V-shaped raceway groove 13 is formed in the longitudinal side wall surface 12 of the track member 3, and a substantially V-shaped raceway groove 17 is formed in the longitudinal side wall surface 17 of the track member 4. A U-shaped raceway groove 18 is formed. The raceway groove 13 and the raceway groove 18 are symmetrically arranged so as to face each other. The raceway groove 13 includes an upper raceway surface 14 and a lower raceway surface 15 that are orthogonal to each other, and both raceway surfaces 14, 1.
5, a raceway groove 18 is formed between the upper raceway surface 19 and the lower raceway surface 20 which are orthogonal to each other.
It has a relief groove 21 formed between the two raceway surfaces 19 and 20. A plurality of cylindrical rollers 22 as rolling elements are disposed in rolling paths formed between the track members 3 and 4 and the track grooves 13 and 18. Each cylindrical roller 22 is held by a plate-shaped holder 23. In this finite linear motion guide unit, racks 24 are provided in the clearance grooves 16 and 21 formed in the raceway grooves 13 and 18, and the racks 24 are provided in mounting holes 31 (see FIG. 7) formed in the cage 23. A rotatably mounted pinion 26 meshes with the rack 24. FIG. 4 will be described later in detail.

Next, the relationship between the cage 23, the cylindrical roller 22 as a rolling element held by the cage 23, and the gear holder 33 for supporting the pinion 26 will be described with reference to FIGS.
This will be described with reference to FIG. Figure 6 shows a finite linear motion guideway 1
1 is a plan view of FIG. 7 is a side view of the finite linear guideway 11 shown in FIG. 6, FIG. 8 is a sectional view of a retainer 23 used for the finite linear guideway 11, and FIG. It is a figure showing a rotation support structure. The retainer 23 is made of a thin metal material, but may be made of an elastic thin material such as plastic. The retainer 23 has retaining holes 27 for fitting the cylindrical rollers 22 at regular intervals. The rotation axes GG (see FIG. 8) of the series of cylindrical rollers 22 are held in the holding holes 27 so as to intersect so as to be alternately inclined in opposite directions. One group of cylindrical rollers 22 inclined to one side is in rolling contact with the lower raceway surface 15 of the track member 3 and the upper raceway surface 19 of the track member 4, and the other group of cylindrical rollers 22 inclined to the other side is a raceway member. 3 and the lower track surface 2 of the track member 4
0 and rolling contact. Each holding hole 27 has 2
A pair of grooves 28, 28 are formed, and a locking claw 29 is formed between each pair of grooves 28, 28 so as to protrude into each holding hole 27. The pair of locking claws 29 are located at positions facing each other, and are in contact with the end face 30 of the cylindrical roller 22. Accordingly, the cylindrical rollers 22 fitted in the holding holes 27 are rotatably held with their end faces 30 in contact with the locking claws 29 formed at the upper and lower ends of the holding holes 27. .

The retainer 23 has a mounting hole 31 for mounting a gear holder 33 that rotatably supports the pinion 26. The mounting hole 31 is a pinion 2
It has the same shape as the holding hole 27 except that it has a passage window 32 through which the periphery of the pinion 26 passes so that the 6 can rotate. A pair of locking claws 29 in the mounting hole 31
May be formed integrally with the retainer 23, but after one locking claw 29 is formed separately and the gear holder 33 is locked by the other locking claw 29 and mounted in the mounting hole 31, One of the locking claws 29 formed as a separate body may be fixed to the side surface of the retainer 23 by bonding or the like so that the gear holder 33 is mounted. The passage window 32 is formed larger than the cross-sectional shape of the pinion 26 so that the pinion 26 can freely rotate with respect to the retainer 23.

FIG. 9 shows a state in which the pinion 26 is rotatably supported by the gear holder 33 held by the holder 23. Gear holder 33 holding pinion 26
Is constituted by a first gear holder, that is, an upper gear holder 34, and a second gear holder, that is, a lower gear holder 35, which are engaged with the mounting holes 31 formed in the retainer 23 and located on both side surfaces of the pinion 26, respectively. That is, pinion 2
6 is mounted on the holder 23 via a gear holder 33 locked on the holder 23.

The gear holder 33 has a divided structure leaving a space for holding the pinion 26 therebetween. That is, since the rotation axis of the pinion 26 is inclined with respect to the retainer 23, the cylindrical roller 22 is divided obliquely with a width slightly larger than the thickness of the pinion 26 as shown in FIGS. It has a shape. FIG. 10 is a diagram of one of the first gear holders 34 of the gear holder 33 having the divided structure.
FIG. 11 is a sectional view taken along the line DD in FIG.
2 is a diagram viewed from the direction of arrow E in FIG. The first gear holder 34 is mounted on the shaft 41 of the pinion 26 (FIG. 13).
(See FIG. 2) for rotation. The support hole 36 is formed at right angles to a slope 37 which is a plane parallel to the side surface of the pinion 26. First gear holder 3
The boundary between the end surface 38 of 4 and the peripheral surface 38a is an edge 39. The end face 38 of the first gear holder 34 has a mounting hole 3
One locking claw 29 comes into contact. The second gear holder 35 has a point-symmetrical structure with the first gear holder 34 and has the same function, and thus a duplicate description will be omitted.

Next, the structure of the pinion 26 will be described. FIG. 13 is a cross-sectional view cut along a plane passing through the shaft of the pinion 26. The pinion 26 has a pinion main body 40 having teeth 42 around it, and a shaft formed integrally with the pinion main body 40 and rotatably supported by a first gear holder 34 and a second gear holder 35 fitted in the holder 23. And a portion 41. Pinion 26 teeth 4
2 meshes with the rack 24 fixed in the clearance grooves 16 and 21 formed in the track members 3 and 4. The pinion 26 and the rack 24 may be made of metal, but may be made of plastic or the like.

In the finite linear motion guide unit, the pinion 26 is mounted on the metal cage 23 as follows. First, the gear holder 33 in which the shaft portion 41 of the pinion 26 is loosely fitted is fitted in one of the mounting holes 31 formed in the holder 23 with one edge 39, and then the other edge 39a
(Not shown) by deforming the other locking claw 29
Fit into 1. Thereafter, by returning the locking claw 29 to its original position, the assembly of the pinion 26 to the holder 23 is completed.

Next, the rack 24 will be described with reference to FIGS.
This will be described with reference to FIG. 14 is a plan view of the rack, FIG. 15 is a side view of the rack shown in FIG. 14, and FIG. 16 is an end view of the rack shown in FIGS. The rack 24 includes teeth 45 having teeth formed thereon, and ends 49 extending on both sides of the teeth 45. Each tooth 46 of the tooth portion 45 (only one position is representatively shown) has a V-shaped concave portion 4.
7 are formed. The deepest part 48 of the recess 47 is at most the depth to the position of the reference pitch line (FF).
No matter which direction the rotating shaft of the cylindrical roller 22 held by the retainer 23 is inclined, the lowermost edge 39 of the cylindrical roller 22 is located at the center of the clearance grooves 16 and 21.
The U-shaped concave portion 47 is formed on each tooth 46 such that the deepest portion 48 is located at the center of the rack 24 in the tooth width direction.

As described above, in order to increase the engagement rigidity between the pinion 26 and the rack 24, the teeth 42 of the pinion 26
If the teeth 46 of the rack 24 are simply enlarged, the cylindrical rollers 22 held by the cage 23 and the teeth 46 of the rack 24 interfere with each other. The guideway 11 and the finite linear guide unit incorporating the same can not be constructed.
According to the present invention, since the concave portion 47 for preventing interference with the cylindrical roller 22 is formed in each tooth 46 of the rack 24, even if the module of the teeth 42 and 46 is enlarged, the tooth may interfere with the cylindrical roller 22. Absent. Therefore, pinion 2
6 and the rack 24 have improved engagement rigidity, and the pinion 2
6 and the rack 24 can be reliably engaged with each other to prevent the retainer 23 from being displaced from the track members 3 and 4. Also, since the size and structure of the clearance grooves 16 and 21 are not changed, the raceway surfaces 14, 15 and 1 of the raceway members 3 and 4 are not changed.
Since there is no decrease in the size of the components 9 and 20, it is possible to support a large load.

Next, an embodiment of a finite linear guideway using a rack 25 having another structure and a finite linear guide unit incorporating the same will be described with reference to FIGS. 17 is a plan view showing a structure for attaching the rack 25 to the track member 3 (or 4) shown in FIGS. 14 to 16, and FIG. 18 is a side view of the structure for attaching the rack 25 to the track member 3 shown in FIG. FIG. 19 and FIG.
5 is an end view of the structure for attaching the rack 25 to the track member 3 shown in FIG. 17 to 19, the same components as those of the rack 24 shown in FIGS. 14 to 16 are denoted by the same reference numerals, and the description thereof will not be repeated. The track members 3 and the like around the rack 25 are indicated by imaginary lines. In this embodiment, the rack 25 is made of a synthetic resin, and a flange 53 for attachment is integrally formed on both ends 49 thereof. The flange 53 has an insertion hole 5 through which an end screw (see reference numeral 10 in FIG. 1) screwed to the track members 3 and 4 is inserted.
1 (FIG. 19) are formed. Rack 25 at the time of production
When the rack 25 is attached to the track members 3 and 4, the flange 53 formed so as to extend on the extension of the tooth portion 45 and the end portion 49 of the rack member 25 extends from the main body of the rack 25 mounted in the clearance grooves 16 and 21. The flanges 53 are bent at right angles to the rack main body, and the end screws 10 with the heads 52 are passed through the insertion holes 51 so that the track members 3 and 4 protrude.
The rack 25 is attached to the track members 3 and 4.

[0028]

As described above, the finite linear guideway and the finite linear guide unit incorporating the finite linear guideway according to the present invention are configured as described above. Even if the cylindrical roller rolls on the raceway between the raceway grooves and moves relative to the pair of raceway members together with the retainer during the relative movement, the tips of the cylindrical rollers are respectively formed in the recesses formed in the teeth of the rack. , And does not interfere with the rack teeth. Therefore, large module teeth can be used for the rack and pinion. Although recesses are formed in the teeth of the rack, the meshing strength between the rack and the pinion is still improved even in consideration of the formation of the recesses. As a result, even if slippage occurs between the rolling cylindrical roller and the raceway surface, the cage does not shift with respect to the raceway member due to the engagement between the rack and the pinion whose strength has been improved. Also,
When such a finite linear guideway is incorporated into a finite linear guide unit, a finite linear guide unit that does not cause displacement can be easily obtained simply by incorporating the finite linear guideway into the unit. be able to.

[Brief description of the drawings]

FIG. 1 is an end view showing an embodiment of a limited linear motion guide unit according to the present invention.

FIG. 2 is a plan view showing a cross section of a part including one finite linear guideway incorporated in the finite linear guide unit shown in FIG. 1;

3 is a view of the finite linear motion guide unit shown in FIG.
It is the fragmentary sectional view seen in A.

FIG. 4 is an enlarged sectional view showing a part C of FIG. 3;

FIG. 5 is a view of the finite linear motion guide unit shown in FIG.
It is sectional drawing seen in B.

FIG. 6 is a plan view of a finite linear guideway according to the present invention.

FIG. 7 is a side view of the finite linear guideway shown in FIG. 6;

FIG. 8 is a sectional view of a retainer used for the finite linear guideway shown in FIGS. 6 and 7;

FIG. 9 is a view showing a rotation support structure of a pinion to a retainer in the finite linear guideway shown in FIGS. 6 and 7;

FIG. 10 is a view showing one first gear holder of the gear holder having a divided structure in the finite direct acting guideway shown in FIGS. 6 and 7;

FIG. 11 is a cross-sectional view taken along line DD in FIG.

12 is a diagram viewed in the direction of arrow E in FIG.

FIG. 13 is a cross-sectional view cut along a plane passing through a shaft of a pinion used in the finite linear motion guideway shown in FIGS. 6 and 7;

FIG. 14 is a plan view of a rack used for the finite linear guideway shown in FIGS. 6 and 7;

FIG. 15 is a side view of the rack shown in FIG. 14;

FIG. 16 is an end view of the rack shown in FIGS. 14 and 15;

FIG. 17 is a plan view showing a state where the rack shown in FIGS. 14 to 16 is attached to a track member.

18 is a side view showing a state where the rack shown in FIG. 17 is attached to a track member.

FIG. 19 is an end view showing a state where the rack shown in FIGS. 17 and 18 is attached to a track member.

FIG. 20 is a perspective view showing a conventional finite linear guideway.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Bed 2 Movable body 3, 4 Track member 10 End screw 11 Finite linear guideway 12, 17 Longitudinal side wall surface 13, 18 Track groove 14, 15 Track surface 16, 21 Relief groove 19, 20 Track surface 22 Cylindrical Roller 23 Cage 24, 25 Rack 26 Pinion 27 Holding hole 29 Locking claw 33 Gear holder 41 Shaft 42 Pinion tooth 46 Rack tooth 47 Depression FF Reference pitch line GG Rotation axis

Claims (7)

[Claims] 1. A pair of track members having track grooves formed in a longitudinal side wall surface, a plurality of cylindrical rollers provided in a track path between the track grooves of each of the track members, and a plurality of cylindrical rollers provided between the track members. A plate-shaped retainer for holding the cylindrical roller, a rack disposed in a clearance groove formed in the track groove, and rotatably mounted in a mounting hole meshed with the rack and formed in the retainer. Finite linear motion comprising a pinion provided and a recess formed in each of the teeth of the rack to prevent the cylindrical rollers rolling on the track from interfering with the teeth of the rack. Shaped guideway. 2. The finite linear guideway according to claim 1, wherein the depth of the recess of the rack is at most a depth up to a reference pitch line of the teeth of the rack. 3. The cylindrical roller is held in a state where a rotation axis is inclined with respect to a plate surface of the retainer, and the raceway groove of the raceway member has a raceway parallel to the rotation axis of the cylindrical roller. 3. The finite linear guide according to claim 1, wherein the guide has a surface, and the concave portion of the rack is formed in a substantially V-shape so that the rolling cylindrical roller passes therethrough. Way. 4. The rack according to claim 1, wherein the rack is attached to the track member by tightening between heads of end screws respectively screwed to both end surfaces of the track member. 2. A finite linear motion guideway according to claim 1. 5. A gear holder comprising: a pinion main body; and a pair of gear holder portions formed on both sides of the pinion main body and formed on shafts formed integrally with the pinion main body and locked by the retainer. 5. The pinion according to claim 1, wherein the pinion is rotatably fitted in a hole formed in the gear holder, the shaft being attached to the retainer through the shaft. Finite linear guideway. 6. A finite linear guideway according to any one of claims 1 to 5, further comprising a pair of moving members which move relative to each other. A finite linear motion guide unit comprising a track member attached to one of the moving members and another track member attached to the other moving member. 7. The one moving member is a bed, and the one track member is an intermediate track member mounted on the bed and having the track grooves formed on both side walls in the longitudinal direction. Is a movable member that straddles the intermediate track member on the bed,
7. The movable body is provided with a pair of the other track members, each of which has the track groove facing the track groove of the intermediate track member formed on the longitudinal side wall surface. Limited linear motion guide unit.