Wheel assembly

A method comprising:

• connecting a wheel assembly to a downhole tool to reduce friction between the downhole tool and a sidewall of a wellbore through which the downhole tool is conveyed, wherein:
• the wheel assembly comprises an axle and a wheel rotatably connected with the axle;
• the downhole tool comprises a threaded bore extending into a sidewall of the downhole tool;
• the axle comprises a bore extending therethrough;
• the wheel comprises a bore extending therethrough;
• the bore of the axle and the bore of the wheel are offset from an axis of rotation of the wheel;
• and
• connecting the wheel assembly to the downhole tool comprises:
• disposing the axle against the sidewall of the downhole tool such that the bore of the axle is aligned with the threaded bore;
• rotating the wheel with respect to the axle to align the bore of the wheel with the bore of the axle;
• inserting a threaded fastener into the threaded bore through the bore of the axle and the bore of the wheel;
• and
• inserting the threaded fastener at least partially into the sidewall of the downhole tool to connect the axle to the downhole tool by threadedly engaging the threaded fastener within the threaded bore to connect the axle to the downhole tool.

An apparatus comprising:

• a wheel assembly for a downhole tool, wherein the wheel assembly is operable to reduce friction between the downhole tool and a sidewall of a wellbore through which the downhole tool is conveyed, and wherein the wheel assembly comprises:
• an axle comprising an outer circumferential groove and a passage extending though the axle;
• a wheel disposed around the axle and comprising an inner circumferential groove, wherein the outer circumferential groove and the inner circumferential groove collectively define a circumferential space between the axle and the wheel, and wherein the passage intersects the circumferential space;
• a plurality of ball bearings disposed within the circumferential space and configured to reduce friction between the axle and the wheel;
• a blocking member disposed within the passage, wherein the blocking member is movable within the passage between a first position in which the ball bearings can be inserted into the circumferential space via the passage and a second position in which the blocking member prevents the ball bearings from exiting the circumferential space via the passage;
• and
• a fastener engaging both the blocking member and the axle when the blocking member is in the second position to prevent the blocking member from moving along the passage from the second position to the first position, wherein the fastener is a threaded fastener comprising a head and a threaded shank, and wherein the threaded shank threadedly engages the blocking member and the head contacts the axle to prevent the blocking member from moving along the passage from the second position to the first position.