JP4564458B2 - Finite linear motion guide unit equipped with cage slip prevention mechanism - Google Patents

Description

  The present invention relates to a finite linear motion guide unit provided with a cage shift prevention mechanism for moving a pair of long rails relative to each other via rolling elements held by a cage.

  In recent years, various types of machine equipment such as semiconductor manufacturing equipment have been required to have various performances such as high acceleration / deceleration, high speed, compactness, high precision, and low sliding resistance. Many finite linear motion guide units have been used. In addition, most of the finite linear motion guide units equipped with the conventional cage slip prevention mechanism are small, but there is a demand for a large finite linear motion guide unit that can be applied to larger types. It became so.

  Conventionally, as a finite linear motion guide unit, a patent application has been filed for the applicant. The finite linear motion guide unit is disposed in a cage having a function of holding a rolling element between the track bases, and the cage is provided with a cage slip prevention mechanism including a rack and a pinion, and is held by the slip prevention mechanism. The holder fitted in the fitting hole formed in the cage is inserted into the pin hole formed in the cage. After that, the end of the pin is crimped and the holder is fixed to the cage. The pinion is rotatably held by the holder by pushing the shaft part of the pinion into the holder hole of the holder part. In the finite linear motion guide unit, the pinion is different from, for example, a tooth shape based on a conventional involute curve, and has a tooth base portion extending from the outer periphery of the disc portion and a semicircular tip integrated therewith. It is comprised from the protrusion part which consists of a part. In addition, the rack is formed with a meshing recess that becomes a tooth groove at a pitch that matches the rotation pitch of the tooth portion of the protruding portion of the pinion that meshes along the longitudinal direction, and the meshing recess is configured integrally with the rack tooth portion and the bottom portion. Has been. Also, the pinion is formed in a circular recess having a diameter slightly larger than the radius of the tip of the tooth portion, and the rack tooth portion is formed on a flat surface without a sharp tip of the tooth tip. Further, the rack is disposed in the clearance groove of the raceway groove. In addition, the pinion rotates into the holder through the holder by inserting the disc part into the holder insertion hole fixed to the holder and pushing the shaft part of the pinion into the holder hole part of the holder part. It is held freely (see, for example, Patent Document 1).

  As another type of finite linear motion guide unit, a patent application has been filed for the applicant. The finite linear motion guide unit is provided with a cage slip prevention mechanism, and the rack is provided on tooth portions provided at predetermined intervals for engaging the pinion and on both side surfaces of the tooth portions. It extends continuously in the longitudinal direction and is integrally formed with side wall portions that connect the tooth portions to each other, and is disposed on a wide bottom portion formed at the back of the escape groove of the raceway. Further, the tooth portion of the rack is formed on a flat surface without a sharp tip of the tooth tip portion. Further, for example, unlike a conventional pinion having a tooth profile based on an involute curve, a pinion is formed with a tooth part spaced at the outer periphery of a disk part and having a circular tip. The disc is inserted into the insertion hole of the holder fixed to the cage, and the shaft of the pinion is pushed into the through hole of the holder, so that the holder is rotatably held by the holder. (For example, refer to Patent Document 2).

Conventionally, a conversion device for rotary motion and linear motion is known. The rotary motion and linear motion conversion device is a device in which a roller is provided on a rack and teeth are formed on a pinion, and a preload is always applied between the rack and the pinion. The pinion is a gear that uses a modified involute curve. Further, the plurality of rollers are provided so as to mesh simultaneously with the plurality of teeth of the rack (see, for example, Patent Document 3).
JP 2003-28157 A JP 2003-176820 A JP-A-10-184842

  However, the finite linear motion guide unit disclosed in the above-mentioned Patent Document 1 is larger in the large finite linear motion guide unit, and the force to prevent the load applied to the rack and pinion is increased, and the rack is firmly fixed to the escape groove. , It is necessary to hold the pinion firmly in the holder. Further, there is a demand for a structure in which the rack and pinion are not disengaged even if the distance between the opposed racks is slightly changed, and there is a problem to be further improved. In other words, the above-mentioned finite linear motion guide unit is suitable for a small type, and in the case of a large type, the holder becomes large, making it difficult to deform the holder itself, and preventing slippage applied to the pinion. The force increases, and there is a problem that the pinion needs to be supported more firmly on the holder.

  In addition, the finite linear motion guide unit disclosed in Patent Document 2 requires the holder to be fixed to the cage with a plurality of pins, which is a troublesome assembly and makes it difficult to process each member. ing. Further, when the above-mentioned finite linear motion guide unit is applied to a large-sized mechanical device, there is a problem that the force for preventing the displacement applied to the pinion is increased, and it is necessary to firmly support the pinion on the holder. In other words, the large finite linear motion guide unit has a large displacement prevention load applied to the rack and pinion, and the pinion is firmly held by the holder, and the long rack is arranged in the relief groove. In addition, there is a problem that the structure of the rack and pinion must not be disengaged even if the interval between the opposed racks is slightly changed.

  Further, the rotational motion and linear motion conversion device disclosed in Patent Document 3 is based on a rack and pinion, and is a power transmission device that enables motion conversion between rotational motion and linear motion. Is formed into a complex tooth profile. However, the cage slip prevention mechanism provided in the finite linear motion guide unit is a simple engagement between a pair of racks and a pinion, and the structure must be such that the engagement is not disengaged. Therefore, the complicated conversion device as described above is not suitable for application to a finite linear motion guide unit.

  SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and is provided with a cage slip prevention mechanism that can be applied to a larger mechanical device than in the prior art. In order to make the pinion to be mounted on the rack larger than the finite linear motion guide units of Patent Document 1 and Patent Document 2 described above, the pinion support structure is configured to be rigid and highly rigid so that the rack & The pinion is constructed so that it can resist the large acting force of the cage, and the rack can be easily placed on the rail even when the rail is long, and the pinion is long. Another object of the present invention is to provide a finite linear motion guide unit having a cage slip prevention mechanism capable of meshing with a rack in response to a position variation between racks.

The present invention relates to a pair of relatively moving track bases each formed with a track groove facing each other on a longitudinal wall surface, and a plurality of rolling elements arranged in a track path formed between the track grooves of the track base A plate-like cage extending in the longitudinal direction, and a displacement prevention mechanism for preventing the cage from shifting between the rails, each of which is provided on the rail. A finite linear motion guide unit comprising a rack and a pinion that includes a tooth portion that meshes with a tooth portion of the rack and that is rotatably mounted on a holder fixed to the cage,
The pinion rotates to the holder as a disc-shaped main body, the teeth extending from the outer periphery of the main body and spaced uniformly in the circumferential direction, and the rotation center of the main body. The tooth portion of the pinion has a flat tooth tip surface in a plane perpendicular to the tooth and the tooth surfaces on both sides extend in parallel to each other so that the tooth thickness is substantially uniform. Formed in a rectangular tooth shape, the rack is disposed in a fitting insertion groove formed in the clearance groove of the raceway groove of the raceway, and the fitting insertion groove is formed at a position away from the groove bottom of the escape groove. The present invention also relates to a finite linear motion guide unit characterized in that a gap is formed between the rack and the groove bottom of the escape groove .

Further, the present invention provides a pair of relatively moving track bases each formed with a track groove facing each other on a longitudinal wall surface, and a plurality of track tracks disposed between the track grooves of the track base. A plate-like cage extending in the longitudinal direction for holding the rolling elements, and a slip prevention mechanism for preventing the cage from shifting between the rails, the slip prevention mechanism being attached to the rails In a finite linear motion guide unit comprising a rack provided respectively, and a pinion having a tooth portion meshing with a tooth portion of the rack and rotatably mounted on a holder fixed to the cage,
The pinion rotates to the holder as a disc-shaped main body, the teeth extending from the outer periphery of the main body and spaced uniformly in the circumferential direction, and the rotation center of the main body. The tooth portion of the pinion has a flat tooth tip surface in a plane perpendicular to the tooth and the tooth surfaces on both sides extend in parallel to each other so that the tooth thickness is substantially uniform. The holder is formed of a pair of holder members that are fitted with the holding plate of the retainer sandwiched therebetween, and the pinion is rotatable on a bearing portion formed on each of the holder members. The present invention relates to a finite linear motion guide unit characterized by being pinched.

  In this finite linear motion guide unit, the holder is configured in a shape in which the holder members are latched and fixed by snap-fit coupling. Further, the snap-fit coupling is formed on a claw portion extending in a tongue shape formed on one of the holder members, a locking step portion formed on the other holder member, and the other holder member. It is latched and fixed by the claw part extended in the shape of a tongue piece, and the latching step part formed in said one said holder member.

The rack includes tooth portions provided at predetermined intervals for meshing the pinion, and continuously extends in the longitudinal direction on both side surfaces of the tooth portions, and connects the tooth portions to each other in an integral structure. A portion constituted by connecting column portions and surrounded by the connecting column portions and between the adjacent tooth portions is formed in an opening through which the tooth portion of the pinion can penetrate. Further, the tooth portion of the rack has a semi-circular surface at the tip. The pinion has a tooth bottom formed in a circular recess and a tooth surface of a tooth end formed in an arc surface in order to make the meshing with the rack smooth.

Further, the present invention provides a pair of relatively moving track bases each formed with a track groove facing each other on a longitudinal wall surface, and a plurality of track tracks disposed between the track grooves of the track base. A plate-like cage extending in the longitudinal direction for holding the rolling elements, and a slip prevention mechanism for preventing the cage from shifting between the rails, the slip prevention mechanism being attached to the rails In a finite linear motion guide unit comprising a rack provided respectively, and a pinion having a tooth portion meshing with a tooth portion of the rack and rotatably mounted on a holder fixed to the cage,
The rack is disposed in an insertion groove formed in the escape groove of the raceway groove of the base, and the fit insertion groove formed in the escape groove of the raceway groove of the base is a groove of the escape groove. be in a position away from the bottom is formed by cutting about the finite linear motion guide unit according to claim.

  This finite linear motion guide unit is configured as described above. The pinion has high rigidity, and the holder that rotatably holds the pinion is strengthened so that it can be applied to a large type. It has a simple structure, is easy to assemble, is compact and can be manufactured at low cost, and can exhibit various effects such as application. Specifically, the pinion tooth profile has a uniform thickness It is formed in a rectangular shape, has long teeth and has rigidity, and even if the rack spacing fluctuates, the pinion and the rack will not disengage and can be meshed stably and smoothly. The pinion is firmly supported on both sides of the holder window, the holder can be easily assembled without excessive deformation to the cage, and can be firmly and stably fixed to the cage, and the pinion shaft is a pair of holder members Thus it is rigidly rotatably disposed to sandwich.

  The finite linear motion guide unit provided with the cage slip prevention mechanism according to the present invention is to provide a cage slip prevention mechanism that can be applied to a larger size than the conventional one. And can be applied to various types of finite linear motion guide units. In this embodiment, the rack and pinion are configured to be disposed in the track between the pair of rails, but the holder is attached to the cage by forming a holder fitting hole in the cage. If possible, it can be attached to any position of the cage, and may be arranged outside the track, for example. In the embodiment, the pair of rails are configured in the same structure, but may be of different lengths and shapes, and can be applied to other types of finite linear motion guide units. In the embodiment, the rolling element is a roller, but it is of course applicable to a finite linear motion guide unit of a ball (not shown) type.

  DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of a finite linear motion guide unit having a cage slip prevention mechanism according to the present invention will be described below with reference to the drawings. First, as shown in FIGS. 1 to 3, this finite linear motion guide unit is connected to the holder 3 that holds the rollers 13 of the rolling elements located between the pair of rails 1 and 2, This is provided with a mechanism 20 for preventing the retainer 3 from shifting by a rack and pinion having a pinion 4 that meshes with the provided racks 5 and 6. This finite linear motion guide unit is configured such that the rails 1 and 2 move relative to each other via a roller 13. The cage 3 is formed of a plate-like holding plate 9 that rotatably holds the roller 13 between the raceway grooves 43 of the raceways 1 and 2 that move relative to each other. In the embodiment, the rails 1 and 2 are relatively moved with a stroke length that is half the stroke length of the rails 1 and 2. However, this finite linear motion guide unit has the position of the rails 1 and 2 depending on various conditions such as load fluctuations, processing accuracy of the raceway surfaces 7 and 8 formed in the raceway groove 43, vertical shaft specifications, high speed and high acceleration / deceleration. Is slightly displaced and the retainer 3 is displaced, so that a displacement prevention mechanism 20 composed of a rack and pinion mechanism composed of a pinion 4 and racks 5 and 6 is incorporated in the retainer 3 so It is comprised so that position shift can be prevented.

  End screws 14 serving as stoppers are respectively attached to both end surfaces 59 of the rails 1 and 2 in order to regulate the stroke of the rails 1 and 2 and the pop-out of the cage 3. The slip prevention mechanism 20 is configured to hold the pinion 4 that meshes with the racks 5 and 6 at the intermediate positions of the racks 5 and 6 attached to the pair of rails 1 and 2, respectively. The device 3 is restricted to a distance that is half the moving distance (moving speed) of the rails 1 and 2 and can control the shifting of the rails 1 and 2 as long as the rack and pinion shift prevention mechanism 20 is engaged. Is. The pinion 4 is rotatably disposed in a holder 10 fitted to the retainer 3 and meshes with a pair of racks 5 and 6. Further, in the embodiment, the pinion 4 is rotatably disposed on a holder 10 disposed at the center position of the cage 3 as shown in FIG. The central position of the cage 3 where the pinion 4 is arranged is a preferable position in consideration of load balance, ensuring of the stroke length, etc., but depending on the case, the arrangement position of the pinion 4 may be an arbitrary position of the cage 3. The position may be sufficient, and a plurality of pinions 4 may be arranged.

  The track bases 1 and 2 are formed in a substantially rectangular cross section in the embodiment, and track grooves 43 are formed along the longitudinal direction of one of the wall surfaces 17 and 18, respectively. The raceway groove 43 is formed in a V shape, and a pair of raceway surfaces 7 and 8 are located on both sides in the longitudinal direction, and a relief groove 19 is formed between the raceway surfaces 7 and 8. Since the rails 1 and 2 are attached to mating members such as bases by bolts (not shown), the rails 1 and 2 have upper and lower surfaces orthogonal to the opposing wall surfaces 17 and 18 where the raceway grooves 43 are formed. Mounting holes 15 are formed in the wall surface 44 at predetermined intervals. The mounting hole 15 is formed in a counterbore hole 16 so that the head of the bolt is hidden, and a screw hole 46 so that the bolt can be screwed from the base side. The cage 3 is arranged between the rail 1 and the rail 2 and holds a plurality of rollers 13 which are rolling elements so as to be rotatable at predetermined intervals. It is formed from the holding plate 9 in which the holding hole 50 is formed. As shown in FIG. 4, the roller 13 is incorporated in the holding plate 9 with the axis center inclined by 45 ° with respect to the side surface 42, that is, the plane of the holding plate 9 of the holder 3, and the adjacent rollers 13 cross each other alternately. In other words, the axes of the adjacent rollers 13 are held on the holding plate 9 by holding claws 28 formed on the holding plate 9 at right angles.

  This finite linear motion guide unit is particularly characterized by the structure of the pinion 4 as shown in FIGS. 6 to 8, and the pinion 4 has a disc-like body portion, that is, a disc portion 51, Extending from the outer periphery of the disk part 51, the disk part 51 formed integrally with the circumferential part of the disk part 51, and the tooth part 41 of an integral structure, and the rotation center of the disk part 51 are held rotatably in the holder 10. The shaft portion 21 is provided. The tooth portion 41 of the pinion 4 has a tooth thickness S which is a chord tooth thickness with a tooth tip surface 61 in a tooth perpendicular plane (or an axis perpendicular plane) being flat and tooth surfaces 65 on both sides extending substantially parallel to each other. It is formed in a substantially constant rectangular tooth shape. Further, in order to make the pinion 4 smoothly mesh with the racks 5 and 6, the tooth bottom 52 is formed in a circular recess, and the tooth surface of the addendum 62 is formed in an arc surface. As shown in FIG. 16, the pinion 4 can be sufficiently engaged so that the engagement does not come off even if the interval between the racks 5 and 6 fluctuates. In particular, the tooth shape of the tooth portion 41 is a rectangular shape. It is characterized by being formed. Since the pinion 4 is formed in a rectangular tooth profile, the entire tooth h can be formed long, the chord tooth thickness S can be formed uniformly thick, and has a rigid shape. Further, the tooth profile of the pinion 4 is analyzed in various ways with the racks 5 and 6, and the tooth ends 62 of the tooth portion 41 are subjected to tooth profile modification so that they mesh smoothly with the racks 5 and 6. That is, it is formed on an arc surface. As shown in FIG. 8, the tooth profile modification Rm has a radius Rm that is substantially the same length as the chord thickness S, and is cut out of the outer portions on both sides of the addendum 62 to form an angle with the flat tip surface 61. The corner R of the part is formed as Rs. Further, the tooth bottom surface of the tooth bottom portion 52 of the pinion 4 is formed in a circular recess having a radius Rf slightly larger than the radius Rc of the tooth tip surfaces 57 of the racks 5 and 6. The number of teeth Z of the pinion 4 may be formed to be about 8 to 12, and in the embodiment, it is formed to an optimal number of 10 teeth. Further, as shown in FIG. 7, the pinion 4 is formed so that the width B of the disc portion 51 is slightly larger than the tooth width B <b> 1 and is held by the holder 10, and the side surface 39 of the window 35 of the holder 10. It is firmly supported by both side surfaces 47 of the disc part 51. FIG. 16 shows a state in which the pair of racks 5 and 6 and the pinion 4 are meshed at an intermediate position (equilibrium position).

  As shown in FIG. 3 and FIG. 13 to FIG. 15, the racks 5 and 6 are respectively disposed in the escape grooves 19 extending along the raceway grooves 43 of the raceways 1 and 2. It is disposed and fixed in the fitting insertion grooves 22 and 23 formed on the surface 60. The racks 5 and 6 may be provided over the entire length of the rails 1 and 2, but it is sufficient that the racks 5 and 6 have a required length including at least the operating range of the rails 1 and 2. In addition, the racks 5 and 6 can be inserted through the fitting insertion grooves 22 and 23 opened in the end surfaces 59 of the rails 1 and 2. As shown in FIGS. 3 and 16, the pinion 4 constituting the slip prevention mechanism 20 is rotatably disposed in a holder 10 fitted to the cage 3 and meshes with a pair of opposed racks 5 and 6. Yes. As shown in FIGS. 9 to 16, the racks 5 and 6 are continuously provided in the longitudinal direction on the tooth portions 53 provided at predetermined intervals for the pinion 4 to mesh with each other and on both side surfaces of the tooth portions 53. It is comprised by the connection pillar part 54 which comprises a pair of side wall part which extends and the said tooth part is mutually connected by integral structure. A portion surrounded by the connecting column portions 54 and the adjacent tooth portions 53 is formed in an opening 56 through which the tooth portion 41 of the pinion 4 can pass. As for the tooth part 53 of the racks 5 and 6, the tooth tip surface 57 is formed in the semicircular surface. In addition, the racks 5 and 6 are arranged in fitting insertion grooves 22 and 23 formed in the clearance grooves 19 of the raceway grooves 43 of the raceways 1 and 2. The insertion grooves 22 and 23 formed on the rails 1 and 2 are formed at positions away from the groove bottom 63 of the escape groove 19, and a gap 58 is formed between the racks 5 and 6 and the groove bottom 63. Yes. The total height of the racks 5 and 6 is substantially the entire tooth hc, so that the total tooth hc can be formed longer and the tooth thickness Sc can be formed thicker. It is configured. Since the racks 5 and 6 are formed with a small total height hc, the racks 5 and 6 can be arranged in a small clearance groove 19 formed between the raceway surfaces 7 and 8 of the raceways 1 and 2.

  The racks 5 and 6 are fixed by being inserted into fitting insertion grooves 22 and 23 formed in the clearance grooves 19 of the rails 1 and 2, and in the fixed state, the end surfaces in the longitudinal direction of the racks 5 and 6 are the rails. It is in a state where it abuts against the end screws 14 attached to the end faces 59 of the first and second ends. In this case, the total length of the rails 1 and 2 and the total length of the racks 5 and 6 are equal. When the racks 5 and 6 are shorter than the rails 1 and 2, dummy spacers (not shown) are arranged in contact with the end surfaces of the racks 5 and 6 so as to have the same length as the rails 1 and 2. The spacer end face can be configured to abut against the end face screw 14 fixed to the rails 1 and 2. This finite linear motion guide unit is large, and the rails 1 and 2 are elongated, and accordingly, the insertion grooves 22 and 23 of the racks 5 and 6 must also be elongated. It will be. For this reason, in this finite linear motion guide unit, cutting by a cutter is employed in order to easily and inexpensively form the long insertion grooves 22 and 23, so that the insertion grooves 22 and 23 are cut. It is formed in a shape that can be made. The shape of the insertion grooves 22 and 23 is formed at a position raised from the groove bottom 63 of the escape groove 19, and cutting can be performed by this position setting by a cutter.

  As shown in FIGS. 13 to 15, the fitting insertion grooves 22, 23 formed in the rails 1, 2 have a gap 58 between the bottom surface of the tooth portion 53 of the racks 5, 6 and the groove bottom 63 of the escape groove 19. It is formed in the position which has. Therefore, even if the tooth tip surface 61 of the pinion 4 passes through the opening 56 in the configuration of the racks 5 and 6 and protrudes from the bottom surface of the tooth portion 53 of the racks 5 and 6, the tooth tip surface 61 of the pinion 4 remains in the relief groove 19. The structure is allowed by the gap 58 without interfering with the groove bottom 63. As shown in FIG. 16, even if the rack interval (or between the reference pitch positions) of the pair of racks 5 and 6 is varied (varied) due to the cutting processing of the insertion grooves 22 and 23, sufficient with the pinion 4 is obtained. It is possible to ensure proper meshing. In addition, the racks 5 and 6 are meshed with the pinion 4 smoothly so that the tooth portions 53 of the racks 5 and 6 are formed on a tooth tip surface 57 having a semicircular cross section. Further, in the tooth tip surfaces 57 of the racks 5 and 6, a V-shaped recessed relief portion 48 is formed so as not to contact the roller 13 of the rolling element in the assembled state shown in FIG. 3.

  In this embodiment, the racks 5 and 6 and the holder 10 are made of synthetic resin. The pinion 4 is formed of parts (so-called molds) manufactured by metal injection molding parts. Therefore, the racks 5 and 6 and the holder 10 as well as the pinion 4 can be formed in a desired shape. In the metal injection molding process, for example, a metal fine powder is prepared, the metal fine powder is kneaded with a binder, then a pellet is formed from the kneaded material, and the pellet is injection molded to produce a pinion molded product. The product can be freeze-dried to vaporize and degrease the binder to remove the binder from the molded product, and the debindered molded product can be sintered in a sintering furnace to produce the final product pinion 4.

  Next, the holder 10 that holds the deviation prevention mechanism 20 will be described with reference to FIGS. The holder 10 has a structure in which the pinion 4 can freely rotate to minimize play and hold it firmly. Further, the holder 10 can be firmly fixed to the cage 3. In particular, the holder 10 is composed of a pair of holder members 11 and 12 that are configured identically, and faces the holder member 11 and the holder member 11 positioned on one side 42 of the holding plate 9 in the fitting hole 30. The holder member 12 is located on the other side surface 42 of the holding plate 9. The holder members 11 and 12 are fixed to the holding plate 9 by narrowing the edge surface 29 of the holding plate 10 around the fitting hole 30 from both sides by sleeve portions 38 extending on both sides in the longitudinal direction. Accordingly, the holder 10 is composed of a pair of holder members 11 and 12 that are fitted with the holding plate 9 interposed therebetween, and the pinion 4 is rotatably held by a bearing portion 36 formed on the holder members 11 and 12 and supported. Since the play with the pinion 4 is minimized, the holder 10 can hold the pinion 4 firmly. The holder 10 has a structure in which a pair of holder members 11 and 12 are firmly fixed to the holding plate 9 while holding the holding plate 9 firmly. The holder members 11 and 12 are formed in the same shape in which the engaging surfaces 40 facing each other are arranged in a complementary shape, and an elongated rectangular window 35 for inserting the pinion 4 is formed in the center. It is formed in a substantially rectangular plate shape.

  The holder 10 is configured in such a shape that the holder members 11 and 12 are latched and fixed by snap-fit coupling. The snap-fit coupling is a hook formed on one holder member 11 or 12 and extending in the shape of a tongue. A certain claw portion 49 and a locking step portion 26 or 27 formed in the other holder member 12 or 11, and a claw portion 49 formed in the other holder member 12 or 11 and extending in a tongue shape, and the one holder member 11 Alternatively, it is latched and fixed by a locking step portion 27 or 26 formed in 12. The holder members 11 and 12 are fitted in fitting holes 30 formed in the holding plate 9 which is the cage 3 in a state where the pinion 4 is fitted and inserted into the window 35 and are opposed to each other. 11 and 12 can be fixed to the holding plate 9 by being locked and fixed by snap-fit coupling while facing each other. In the holder 10, when the holder members 11, 12 are combined, the fitting portions that become the convex portions 31, 32 of the respective engagement surfaces 40 are combined to fit into the fitting holes 30 of the holding plate 9. Become. The fitting hole 30 of the holding plate 9 is formed in, for example, a rectangular window or fitting hole 30 having a size corresponding to two of the holding holes 50 of the roller 13. In the embodiment, the fitting hole 30 is formed by punching out the portion between the holding holes 50 located in the central portion from the material in which the holding holes 50 are formed over the entire length of the holding plate 9. As described above, the holder 10 combines the holder members 11 and 12 having the same configuration and has a snap-fit coupling method, so the number of parts is small, simple structure, low cost, easy assembly, compact, flexible application, etc. It is something that demonstrates the effect of.

  The holder members 11 and 12 have a sufficient wall surface over the entire length in the longitudinal direction of the window 35 because the side surface 39, which is the surface of the window 35 formed on each of them, firmly regulates the side portion 47 of the pinion 4. A portion forming the side surface 39 is formed in a mountain-shaped convex portion 66. Further, the convex portions 31, 32 provided on the holder members 11, 12 are formed in such a shape that their outer surfaces are fitted into the fitting holes 30 of the holding plate 9. The opposing surfaces of the inner surfaces of the holder members 11, 12 facing the holding plate 9 constitute an engaging surface 40 whose peripheral surfaces become sleeve portions 38, and the opposing engaging surface 40 is an insertion hole of the holding plate 9. The holding plate 9 is sandwiched in contact with the peripheral surface 29 around 30. That is, the portion between the engagement surfaces 40 facing the fitting hole 35 of the holding plate 9 fits snugly into the fitting hole 35 of the holding plate 9, and thus protrudes from the engagement surface 40 to become a fitting portion. Protrusions 31 and 32 are formed. Moreover, the convex parts 31 and 32 are each formed in the size of the half of the fitting hole 35, respectively, and are formed in the one side of the longitudinal direction of the holder members 11 and 12. FIG. Furthermore, the holder members 11 and 12 are such that the protruding amount 31 or 32 of one holder member 11 or 12 is slightly smaller than the thickness of the holding plate 9, and the other holder member 12 or 11 Are arranged so as to face the same surface as the surface of the sleeve portion 38, that is, the surface without the convex portions 31, 32.

  Further, the engaging surface 40 which is the opposing surface of the holder members 11 and 12 is provided with a recess so as to wrap the shaft portion 21 in order to hold the shaft portion 21 of the pinion 4 firmly and freely by the holder members 11 and 12. The bearing portions 36 are formed on both sides of the center of the window portion 35 of the holder members 11 and 12. Further, in order for the holder members 11 and 12 to be united with each other with high precision, two positioning pins 33 are formed on one diagonal line with the bearing portion 36 interposed therebetween, and on the other diagonal line. A pin hole 34 into which the positioning pin 33 is fitted is formed at a 180 ° point symmetrical position. In addition, tongue-like claws 24 and 25 extending downward from the facing surface 42 of the holding plate 9 are formed at one end in the longitudinal direction of the holder members 11 and 12, respectively. Are formed with insertion grooves 37 that are recessed to allow the claw portions 25 or 24 to be inserted therethrough. The tongue-like claw portions 24 and 25 provided on the holder members 11 and 12 respectively have tip portions formed on the hooks 49, respectively. Planar locking step portions 26 and 27 to which hooks 49 of the claw portions 24 and 25 are respectively locked are formed on the portions forming the end portions of the outer window portions 35 following the insertion grooves 37 of the holder members 11 and 12. Is formed.

  The finite linear motion guide unit according to the present invention is preferable for use in various mechanical devices such as semiconductor manufacturing apparatuses, precision measuring instruments, inspection machines, assembly machines, machine tools, and various robots.

It is a perspective view which shows the Example of the finite linear motion guide unit by this invention including a cross-sectional part. It is a front view which shows the finite linear motion guide unit of FIG. It is sectional drawing which shows the AA cross section in the finite linear motion guide unit of FIG. It is a top view which shows the holder | retainer in the finite linear motion guide unit of FIG. It is sectional drawing which shows the BB cross section in the holder | retainer of FIG. It is a front view which shows the pinion integrated in the finite linear motion guide unit of FIG. It is sectional drawing which shows CC cross section in the pinion of FIG. It is an enlarged front view which shows the code | symbol P part of the pinion of FIG. It is a front view which shows the rack integrated in the finite linear motion guide unit of FIG. FIG. 10 is a plan view showing the rack of FIG. 9. FIG. 10 is a side view showing the rack of FIG. 9. It is sectional drawing which shows the DD cross section in the rack of FIG. It is an end view which shows the arrangement | positioning state of the rack to the way in the finite linear motion guide unit of FIG. It is sectional drawing which shows a part of longitudinal direction in the EE cross section of the arrangement | positioning state of the rack to the way of FIG. It is a top view which shows a part of longitudinal direction of the arrangement | positioning state of the rack to the way of FIG. It is explanatory drawing which shows the meshing state of the pinion and rack which comprise the shift | offset | difference prevention mechanism in FIG. It is a disassembled perspective view which shows the assembly state of the slip prevention mechanism in FIG.

DESCRIPTION OF SYMBOLS 1, 2 Way table 3 Cage 4 Pinion 5, 6 Rack 9 Holding plate 10 Holder 11, 12 Holder member 13 Roller (rolling element)
17, 18 Wall surface 19 Escape groove 20 Deviation prevention mechanism 21 Shaft part 22, 23 Insertion groove 24, 25 Claw part 26, 27 Locking step part 36 Bearing part 41 , 53 tooth part 43 Track groove 45 Track path 51 Disk part (Main body)
54 connecting column 56 opening 58 gap 61 tooth tip surface 62 tooth end 63 groove bottom 65 tooth surface S tooth thickness

Claims (8)

A pair of relatively moving track bases formed with track grooves facing each other on a longitudinal wall surface, and holding a plurality of rolling elements arranged in a track path formed between the track grooves of the track base. A plate-like retainer extending in the longitudinal direction, and a displacement prevention mechanism for preventing the retainer from being displaced between the track bases, the slip prevention mechanism being a rack provided on each of the track bases, And a finite linear motion guide unit comprising a pinion having a tooth portion meshing with each tooth portion of the rack and rotatably mounted on a holder fixed to the cage,
The pinion rotates to the holder as a disc-shaped main body, the teeth extending from the outer periphery of the main body and spaced uniformly in the circumferential direction, and the rotation center of the main body. The tooth portion of the pinion has a flat tooth tip surface in a plane perpendicular to the tooth and the tooth surfaces on both sides extend in parallel to each other so that the tooth thickness is substantially uniform. Formed in a rectangular tooth shape, the rack is disposed in a fitting insertion groove formed in the clearance groove of the raceway groove of the raceway, and the fitting insertion groove is formed at a position away from the groove bottom of the escape groove. A finite linear motion guide unit , wherein a gap is formed between the rack and the groove bottom of the escape groove . A pair of relatively moving track bases formed with track grooves facing each other on a longitudinal wall surface, and holding a plurality of rolling elements arranged in a track path formed between the track grooves of the track base. A plate-like retainer extending in the longitudinal direction, and a displacement prevention mechanism for preventing the retainer from being displaced between the track bases, the slip prevention mechanism being a rack provided on each of the track bases, And a finite linear motion guide unit comprising a pinion having a tooth portion meshing with each tooth portion of the rack and rotatably mounted on a holder fixed to the cage,
The pinion rotates to the holder as a disc-shaped main body, the teeth extending from the outer periphery of the main body and spaced uniformly in the circumferential direction, and the rotation center of the main body. The tooth portion of the pinion has a flat tooth tip surface in a plane perpendicular to the tooth and the tooth surfaces on both sides extend in parallel to each other so that the tooth thickness is substantially uniform. The holder is formed of a pair of holder members that are fitted with the holding plate of the retainer sandwiched therebetween, and the pinion is rotatable on a bearing portion formed on each of the holder members. finite linear motion guide unit characterized in that it is sandwiched. The finite linear motion guide unit according to claim 2, wherein the holder is configured so that the holder members are latched and fixed by snap-fit coupling. The snap-fit coupling includes a claw portion extending in the shape of a tongue piece formed in one of the holder members, a locking step portion formed in the other holder member, and a tongue piece formed in the other holder member The finite linear motion guide unit according to claim 3 , wherein the finite linear motion guide unit is hooked and fixed by a claw portion extending in a shape and a locking step portion formed on the one of the holder members. The rack includes teeth provided at predetermined intervals for meshing the pinion, and a connecting column that continuously extends in the longitudinal direction on both side surfaces of the teeth and connects the teeth to each other in an integral structure. 5. A portion that is formed by a portion and is surrounded by the connecting column portion and between the adjacent tooth portions is formed in an opening through which the tooth portion of the pinion can penetrate. The finite linear motion guide unit according to any one of the above. The finite linear motion guide unit according to any one of claims 1 to 5 , wherein the tooth portion of the rack has a semicircular surface at a tooth tip surface . 7. The pinion according to any one of claims 1 to 6 , wherein a tooth bottom is formed in a circular recess and a tooth surface of a tooth end is formed in an arc surface in order to make the meshing with the rack smooth. The finite linear motion guide unit according to claim 1. A pair of relatively moving track bases formed with track grooves facing each other on a longitudinal wall surface, and holding a plurality of rolling elements arranged in a track path formed between the track grooves of the track base. A plate-like retainer extending in the longitudinal direction, and a displacement prevention mechanism for preventing the retainer from being displaced between the track bases, the slip prevention mechanism being a rack provided on each of the track bases, And a finite linear motion guide unit comprising a pinion having a tooth portion meshing with each tooth portion of the rack and rotatably mounted on a holder fixed to the cage,
The rack is disposed in an insertion groove formed in the escape groove of the raceway groove of the base, and the fit insertion groove formed in the escape groove of the raceway groove of the base is a groove of the escape groove. A finite linear motion guide unit formed by cutting at a position away from the bottom .

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