Linear guideway and end module thereof

A linear guideway, comprising:

• a rail having two lateral surfaces being opposite to each other;
• a sliding module slidably disposed on the rail along a sliding direction and including:
• a slider including a base portion and two lateral portions that extend from the base portion, wherein inner sides of the two lateral portions face toward the two lateral surfaces of the rail, respectively;
• and
• a plurality of rollers disposed on the slider and the rail;
• and
• two end modules respectively fixed to two assembling end surfaces of the slider and being slidably disposed on the rail, wherein each of the two end modules includes:
• a cap fixed to the corresponding assembling end surface and including a transverse segment and two lateral segments that are respectively connected to two ends of the transverse segment, wherein the transverse segment corresponds in position to the base portion, and two lateral segments respectively correspond in position to the two lateral portions;
• and
• a circulation sheet being oil-swollen and sandwiched between the cap and the corresponding assembling end surface, wherein the circulation sheet is engaged in the transverse segment and the two lateral segments so as to jointly define an oil injection channel;
• wherein the circulation sheet and the two lateral segments of the cap jointly define a plurality of turning channels, wherein the turning channels are in cooperation with the slider and the rail to jointly define a plurality of rolling channels, and wherein the oil injection channel is in spatial communication with the rolling channels, and the rollers are rollably disposed in the rolling channels;
• wherein, in each of the two end modules, when a lubricating oil is injected into the oil injection channel, the circulation sheet absorbs a part of a total volume of the lubricating oil and expands so as to be fitted to the assembling end surface, the transverse segment, and the two lateral segments.