Tapered Bore Pillow Block Bearings (UKP+H Series): When and Why to Use an Adapter Sleeve
A UKP+H pillow block replaces direct set-screw locking with a tapered-bore insert mounted on an adapter sleeve. The bearing bore has a 1:12 taper, while the H-series sleeve fits over a straight shaft and provides the tapered interface, locknut and washer used to secure the bearing axially.
This arrangement is useful when the machine or maintenance practice benefits from sleeve mounting, but the bearing and adapter must be selected as a pair.
How adapter-sleeve mounting works
The H-series sleeve sits on the shaft. As the tapered-bore UK insert is driven onto the sleeve by the locknut, the taper creates the radial grip and establishes the bearing position. The lock washer secures the nut after the correct mounting position is reached.
Because the sleeve is part of the shaft connection, using the wrong adapter number can change the shaft diameter or axial position even if the housing itself looks correct.
Why choose an adapter arrangement
The planning guide highlights vibration tolerance, even shaft grip and easier removal as reasons to review UKP+H. It can also be useful where a straight shaft is already in service and the designer wants a tapered-bearing mounting system without machining a taper directly into the shaft.
Matching UK inserts to H-series adapters
Adapter selection uses the matched adapter number, locknut, lock washer and UK bearing number. The pair should be ordered from the table rather than inferred from the last two digits alone.
| Example bearing | Adapter family shown in supplied range | Selection note |
|---|---|---|
| EP-UK205 | H/HE/HA/HS 2305 family depending on shaft standard | Confirm actual shaft diameter and sleeve variant |
| EP-UK206 | 2306 adapter family | Keep locknut/washer with adapter selection |
| EP-UK207 | 2307 adapter family | Verify housing and shaft together |
| EP-UK210 | 2310 adapter family | Larger housing/shaft interface; check full table |
UKP+H pillow-block range
EP-UKP+H pillow-block combinations span multiple 200- and 300-series sizes. Each row includes shaft diameter, housing dimensions, bolt size, bearing number, housing number, adapter number and mass. This is the information needed for a replacement or new support design.
Installation sequence
- Confirm the shaft diameter, bearing, adapter sleeve, locknut, lock washer and housing are the intended matched set.
- Position the housing/support and establish the shaft line before fully clamping both supports.
- Place the adapter sleeve on the clean shaft and move the UK bearing onto the taper.
- Tighten the locknut using the approved mounting method for the selected bearing/sleeve; do not improvise an axial position from appearance alone.
- Secure the lock washer and verify shaft rotation and housing alignment before start-up.
UKP+H vs UCP set-screw
| Decision | EP-UCP set screw | EP-UKP + H adapter |
|---|---|---|
| Shaft connection | Two screws contact straight shaft | Tapered insert grips adapter sleeve |
| Extra hardware | No separate sleeve | Adapter, locknut and washer |
| Replacement information | Bore + housing + screw details | Shaft + UK bearing + exact adapter + housing |
| Service decision | Simple common arrangement | Useful where adapter mounting is desired or already installed |
What the adapter sleeve changes
A tapered-bore insert with an H-series adapter sleeve uses the sleeve, nut and washer to grip a straight shaft. This creates a different installation and removal process from set-screw UCP units. The bearing model and adapter model must be matched as a system; the correct shaft diameter alone is not enough.
Installation sequence matters
Clean the shaft, position the sleeve and housing components, then draw the tapered-bore insert onto the sleeve using the specified nut procedure. Monitor the criteria specified for the bearing arrangement rather than simply tightening until the nut “feels tight.” Secure the locking device, check axial position and verify the shaft rotates freely. For service work, plan enough space to loosen the nut and release the bearing from the taper.
When to stay with set screws
If the existing machine has a simple straight shaft, limited axial space and a proven set-screw arrangement, an adapter sleeve may add unnecessary complexity. Use UKP+H when the machine or maintenance strategy benefits from that mounting method and the full housing / sleeve geometry fits.
Need a model checked against your machine? Send the dimensions with your RFQ.