Koyo YCRS-12 track roller, D 19.05 mm, bore 6.355 mm

The Koyo YCRS-12 is an inch series yoke-type track roller for straddle mounting. Track rollers, also known as cam followers, have thick-walled outer rings that run directly on a track. The thick outer rings give high load-carrying capability while keeping distortion and bending stresses low, and JTEKT designs them to withstand heavy rolling and shock loads on track-type or cam-controlled equipment. It is a non-separable unit with an outer ring, a full complement of needle rollers, an inner ring, self-lubricating resin internal thrust washers and two retaining washers fastened to the inner ring.

Seals in the outer ring counterbores seal against the retaining washers to retain lubricant and exclude foreign matter. Inch series track rollers have a black-oxide finish on external surfaces. Koyo bearings are made by JTEKT Corporation.

Where this product is used

• Ram support rollers
• Material handling equipment
• Indexing equipment
• Track-type and cam-controlled equipment
• Forklift truck guide rollers
• Machine tool table ways
• Reciprocating slide feeding mechanisms

Features

• Cylindrical outer diameter
• Non-separable sealed yoke-type unit with full complement of needle rollers and resin internal thrust washers
• Dynamic load rating as a track roller Cw 6.27 kN; basic dynamic load rating as a bearing C 10.14 kN
• Grease lubrication speed rating 3,800 min-1
• Thick-walled outer ring for high load capacity with low distortion and bending stress

Key specifications

Selecting the right option

Cw is the dynamic load rating as a track roller. For rating life (L10) calculations the applied radial load must not be greater than Cw/4 under ideal operating conditions of alignment, lubrication and temperature.

Fr perm is the maximum permissible dynamic radial load and F0r perm is the maximum permissible static radial load as a track roller. The F0r perm values give a minimum static factor fs of 0.7 for the worst internal load distribution, and they must not be exceeded, because exceeding them may cause permanent damage to the track roller.

Fitting and use

Clamp the unit endwise between flat parallel faces, at right angles to the axis, so the retaining washers cannot come off under load. If it cannot be clamped, use a close axial fit in the yoke. The unit should be mounted on a high strength shaft or bolt with the tight transition fit (h6) when loads are high, the loose transition fit (f7) when loads are moderate, and the loose fit on an unhardened shaft or bolt for light loads.

The machine element supporting the bolt must be rigid enough to resist local crushing under the applied load and to resist bending, which would load the rollers unevenly. Sealed yoke-type units are normally supplied with a medium temperature grease, and oil is the preferred lubricant.

Related products

Also available from Koyo: the CRSB-40 cam follower and the NUTR track roller range.