Description

SI Cast Iron Hanger Bearings for SC Screw Conveyors

SI Cast Iron Hanger Bearings are installed at intermediate shaft joints inside SC tubular Screw Conveyors.

The cast iron hanger body supports the centre connection between adjoining screw shaft sections. A self-lubricating bearing arrangement is incorporated within the housing, while the splined interfaces connect with the shaft components on both sides.

Six SI models cover SC168, SC219, SC273, SC323, SC325 and SC407 conveyor configurations. Each model combines a specific housing size, spline, mounting thread and overall length to match the corresponding conveyor and shaft assembly.

Cast Iron Hanger Assembly at the Intermediate Shaft Joint

The SI occupies the open position between adjacent Screw Flight sections. The hanger body, centre bearing support and shaft connection are combined in one assembly, allowing the two screw shaft sections to meet at a defined support point.

The flighting does not pass through the hanger body. Sufficient clearance must remain around the housing, and the splined shaft ends must correspond with the selected SI model.

For new conveyor production, the hanger bearing is matched with the tube diameter, shaft sections and Shaft Coupling as part of the complete centre connection. For replacement work, the installed dimensions should be checked when the shaft or coupling has previously been repaired.

SI Hanger Bearing Models and Dimensions

Dimensions: mm

The conveyor designation and the complete SI model should be read together. In particular:

• SI323 corresponds to the SC325 configuration.
• SI325 corresponds to the SC323 configuration.

These two models also share a dimension A of 157.5 mm, but their shaft connection, dimension C and overall length are different.

Similar Housing Measurements Do Not Confirm the Same SI Model

SI323 and SI325 illustrate why the external hanger width cannot be used as the only replacement reference.

Although the cast iron bodies have the same A measurement, the two assemblies connect to different screw shaft systems.

SI325 and SI407 also share a 60 × 55 spline and 295 mm overall length, but they use different housing dimensions and mounting threads. The complete combination of housing and connection data determines the required model.

Matching the SI with the Existing Shaft Components

The spline on the SI must correspond with the adjoining Screw Shaft and coupling. A matching conveyor diameter or housing width cannot compensate for a different shaft interface.

Before replacing an existing hanger bearing, check that:

• Both adjoining shaft sections use the required spline;
• The coupling corresponds with the same connection;
• The shaft ends can engage without being forced into position;
• The centre spacing remains suitable for the hanger body;
• The adjacent screw flights leave adequate clearance around the housing.

Previous repairs may change the shaft section, coupling or hanger position while leaving the conveyor tube unchanged. In that case, the current physical connection should be checked before repeating an earlier order.

Identifying an SI When the Marking Is Unreadable

A complete, readable SI model provides the clearest replacement reference.

When the marking has worn away, use the following details together:

• Conveyor designation
• Dimensions A and C
• Shaft diameter
• DIN 5482 spline
• Mounting thread
• Overall length

Clear photographs should show the complete cast iron body, both connection ends and the installed hanger position. Include a ruler or caliper when photographing dimensions.

An exterior photograph without measurements may indicate an SI-style hanger body, but it cannot reliably confirm the shaft interface or distinguish models with similar housing dimensions.

Frequently Asked Questions about SI Cast Iron Hanger Bearings

Our invoice says SI323, but the conveyor identification says SC325. Is that combination correct?

Yes.

SI323 corresponds to the SC325 conveyor configuration. Before repeating the order, confirm the 157.5 mm dimension A, 51 mm dimension C, 40 × 36 spline and 245 mm overall length.

SI325 should not be selected simply because its model number appears closer to SC325.

The old hanger has no readable model and measures 157.5 mm across dimension A. How do we identify it?

Dimension A alone cannot distinguish SI323 from SI325 because both measure 157.5 mm.

Check the overall length, dimension C, shaft diameter and spline. SI323 is 245 mm long with a 40 × 36 connection, while SI325 is 295 mm long with a 60 × 55 connection.

We plan to keep the existing shaft coupling. What must be checked before ordering a new SI?

Confirm that the coupling spline matches the selected SI and both adjoining shaft sections.

The coupling should also be checked for worn or rounded spline surfaces. Retaining a connection with a different or damaged spline may prevent the new hanger bearing from fitting correctly.

The screw shaft was rebuilt after the original SI was purchased. Can we reorder from the old invoice?

The old invoice is useful as a reference, but the current shaft connection should be measured first.

A replacement shaft or coupling may have changed the spline, centre spacing or hanger position. The new SI must match the components currently installed in the conveyor.

SI325 and SI407 use the same spline and overall length. Are the complete hanger bearings interchangeable?

No.

SI325 has a 157.5 mm dimension A, 54 mm dimension C and M14 mounting thread. SI407 has a 197 mm dimension A, 60 mm dimension C and M20 mounting thread.

Their shaft interfaces are similar, but the cast iron bodies and mounting arrangements correspond to different conveyor configurations.

The cast iron housing is damaged, but the shaft connections still appear usable. Can we identify the replacement without measuring the splines?

The splines should still be checked.

External damage to the housing does not confirm the condition or dimensions of the shaft connection. Measure the spline and inspect both adjoining shaft ends before selecting the replacement assembly.