HM120846/HM120817XD Railway train bearings

HM120846/HM120817XD is imperial TDO integral double‑cup double‑row tapered roller bearing from Boyuan, assembled with two cone assemblies HM120846 and one one‑piece double cup HM120817XD with stamped‑steel cage. It shares the identical double cup HM120817XD with HM120848/HM120817XD. The main difference is cone bore: HM120846 bore 99.957 mm vs HM120848 bore 101.600 mm. It is Class‑B derivative railway axle‑box bearing for slightly smaller journal wheelsets, also used for heavy‑duty construction machinery, mining equipment and heavy gearboxesTimken. Back‑to‑back configuration withstands heavy radial load plus bidirectional axial loads.

项目 Item	公制 Metric	英制 Imperial
内径 d Bore	99.957 mm	3.9353 in
外径 D Outer Diameter	165.100 mm	6.5000 in
单内圈宽度 B Cone width	49.213 mm	1.9375 in
双外圈总宽 C Double cup width	114.300 mm	4.5000 in
装配总宽 T Assembly width	106.581 mm	4.1961 in
重量 Weight	8.62 kg	19.00 lb

Double cup HM120817XD is one‑piece unit. Two HM120846 cones must be used as matched set. Do NOT interchange with HM120848 cones, bore sizes differ.
Hot mounting preferred for railway application; heating temperature ≤120℃, open‑flame heating strictly forbidden.
Verify shoulder dimensions: shaft shoulder db=111.0 mm, housing shoulder Da=154.9 mm; shaft fillet ≤1.5 mm, housing fillet ≤1.0 mm.
Fill 1/3‑1/2 of internal volume with grease; over‑greasing causes overheating.
Follow AAR railway assembly specification for installation.