A linear motion guide unit prevents damage to a corner portion of an end surface of a carriage resulting from high-speed rolling of the rolling elements, and eliminates the need for strict dimensional management of facing end surfaces of the carriage and a spacer. A crowning is formed at an end portion of the carriage, and an R chamfered portion is formed at a corner of an end surface of the carriage. An R chamfered portion is formed at a corner of the end surface of the spacer. The R chamfered portions define a valley portion between the facing surfaces of the carriage and the spacer. The rolling elements roll above the valley portion while striding it to thereby be prevented from colliding against the corner portion of the end surface of the carriage, whereby damage to the corner portion of the end surface of the carriage can be prevented.

In a linear motion guide unit, a raceway groove formed in a casing of a slider includes a first raceway surface extending along the length direction of the slider and a second raceway surface facing the first raceway surface and extending along the length direction of the slider. The second raceway surface includes a first portion including a center portion in a length direction of the casing, and a second portion including end portions in the length direction of the casing and having a wall surface shape different from a wall surface shape of the first portion. In the first portion, the first raceway surface and the second raceway surface define a symmetric Gothic arch groove, and in the second portion, the second raceway surface has a surface recessed from a position symmetric to the first raceway surface.

A linear motion guide unit prevents damage to a corner portion of an end surface of a carriage resulting from high-speed rolling of rollers, and eliminates the need for strict dimensional management of facing end surfaces of the carriage and a spacer. A crowning is formed at an end portion of the carriage, and an R chamfered portion is formed at a corner of an end surface of the carriage. An R chamfered portion is formed at a corner of the end surface of the spacer. The R chamfered portions define a valley portion between the facing surfaces of the carriage and the spacer. The rollers roll above the valley portion while striding it to thereby be prevented from colliding against the corner portion of the end surface of the carriage, whereby damage to the corner portion of the end surface of the carriage can be prevented.

A curvilinear motion rolling guide unit is such that pipe members adapted to form return passages are disposed respectively at undercuts of wings of an arcuate casing, thereby reducing working costs. A slider has a casing and end caps fixed to respective opposite ends of the casing. Pipe members adapted to form return passages are disposed at the respective undercuts formed on the wings of the casing. Cover members have longitudinally extending grooves, respectively, for covering the pipe members. Fitting grooves formed at opposite ends of the grooves of the cover members are fitted to direction changing passages provided in the respective end caps, whereby the cover members are fixed to the end caps.

A threadless linear guide includes a rail, a slide block, a recirculation assembly, and a fixing member. The slide block, the recirculation assembly, and the fixing member are positionable with respect to each other through retention engagements therebetween so that the components can be coupled to each other without screws. A reinforcement plate is provided for reinforcing the strength of the recirculation assembly for the recirculation assembly is generally formed of injecting molding, while the fixing member and the reinforcement plate are made of metal. Thus, with the fixing member and the reinforcement plate enclosing the recirculation assembly, any foreign object jamming in the interior would not cause the rolling bodies to eject out through the recirculation assembly during the operation of rolling bodies.

A circulating module of a linear guideway includes a slider and a circulator. The slider has two carrying surfaces arranged on two opposite outer surface thereof. Each carrying surface includes a first circular-arc segment and two second circular segments respectively arranged at two opposite sides of the first circular-arc segment, and a radius of each first circular-arc segment is smaller than that of each second circular-arc segment. The circulator includes two inner circular-arc surfaces. The slider is inserted into the circulator, the carrying surfaces stretch a distance between the inner circular-arc surfaces, each inner circular-arc surface is abutted against the two second circular-arc segments of the corresponding carrying surface, and a gap is formed between each inner circular-arc surface and the corresponding first circular-arc segments.

An end module of a linear guideway includes an end cap, a cover, and a lubricating sheet. The end cap has an accommodating trough, and the cover is installed on the end cap to cover the accommodating trough, so a surface of the end cap faces a surface of the cover. At least one supporting pillar is formed on one of the two facing surfaces of the end cap and the cover, and the supporting pillar abuts against the other one of the two facing surfaces of the end cap and the cover. The lubricating sheet is received in the accommodating trough. The lubricating sheet has at least one penetrating hole, and the supporting pillar is inserted into the penetrating hole. Thus, the lubricating sheet of the instant disclosure is provided without any deformation, which is caused by the end cap and the cover.

A curvilinear motion rolling guide unit is such that pipe members adapted to form return passages are disposed respectively at undercuts of wings of an arcuate casing, thereby reducing working costs. A slider has a casing and end caps fixed to respective opposite ends of the casing. Pipe members adapted to form return passages are disposed at the respective undercuts formed on the wings of the casing. Cover members have longitudinally extending grooves, respectively, for covering the pipe members. Fitting grooves formed at opposite ends of the grooves of the cover members are fitted to direction changing passages provided in the respective end caps, whereby the cover members are fixed to the end caps.

A circulating module of a linear guideway includes a slider and a circulator. The slider has two carrying surfaces arranged on two opposite outer surface thereof. Each carrying surface includes a first circular-arc segment and two second circular segments respectively arranged at two opposite sides of the first circular-arc segment, and a radius of each first circular-arc segment is smaller than that of each second circular-arc segment. The circulator includes two inner circular-arc surfaces. The slider is inserted into the circulator, the carrying surfaces stretch a distance between the inner circular-arc surfaces, each inner circular-arc surface is abutted against the two second circular-arc segments of the corresponding carrying surface, and a gap is formed between each inner circular-arc surface and the corresponding first circular-arc segments.

An end module of a linear guideway includes an end cap, a cover, and a lubricating sheet. The end cap has an accommodating trough, and the cover is installed on the end cap to cover the accommodating trough, so a surface of the end cap faces a surface of the cover. At least one supporting pillar is formed on one of the two facing surfaces of the end cap and the cover, and the supporting pillar abuts against the other one of the two facing surfaces of the end cap and the cover. The lubricating sheet is received in the accommodating trough. The lubricating sheet has at least one penetrating hole, and the supporting pillar is inserted into the penetrating hole. Thus, the lubricating sheet of the instant disclosure is provided without any deformation, which is caused by the end cap and the cover.