2229250 Imer Workman Mixer Shaft Key

Features

• Fits the workman 250, 350 & 420 models
• Replacement gear box shaft key. 6X6X14.

The Imer Workman Mixer Shaft Key is a small but critical OEM drive component that locks the mixer shaft to its pulley or gear, ensuring the drum on your Imer Workman concrete or mortar mixer turns reliably under load without slipping. This specially sized metal key sits in the keyed slot (keyway) between the shaft and the hub, transmitting torque from the motor and gearbox to the drum and making efficient, safe mixing possible.

What is the Imer Workman Mixer Shaft Key?

An Imer Workman Mixer Shaft Key is a precision‑machined rectangular or square metal bar designed to fit tightly into a keyway cut into the mixer shaft and the mating component, such as a pulley, sprocket, or gear. In Workman mixers, the shaft key acts as the mechanical link that prevents rotation between the shaft and the part it drives. Without this key, the pulley or gear would spin on the shaft and the drum would not turn, even though the motor is running.

For SEO and purchasing purposes, this part is often described as:

• “Imer Workman Mixer Shaft Key”

• “Shaft key for Imer Workman 250 / Workman 350 mixer”

• “OEM key for Imer mixer shaft and pulley”

It is an OEM replacement part, meaning it is manufactured to Imer’s original specifications for length, width, and height so it fits perfectly into the Workman mixer shaft and hub keyways.

Where the Shaft Key Fits on an Imer Workman Mixer

On an Imer Workman mixer, the shaft key is used in the drive line that connects the motor to the drum. The exact arrangement can vary slightly by model (Workman 250, Workman 350, Workman 250 II, etc.), but the principle is the same:

• The motor drives a pulley or sprocket.

• That pulley is mounted on a shaft that goes into the gearbox or turns the drum.

• The shaft key sits in a slot on the shaft and in the matching slot in the pulley hub.

• When the motor turns, torque is transferred through the key into the shaft and ultimately into the mixer drum.

You may also find shaft keys inside the gearbox assembly, locking gears onto shafts in the Workman reduction gearbox. In both cases, the key is what prevents rotation between the shaft and its driven component.

Why the Shaft Key is So Important

The Imer Workman Mixer Shaft Key is one of the smallest parts in the mixer, but its job is essential:

• It transmits torque from the motor/gearbox to the drum.

• It prevents slippage between shaft and pulley or gear under load.

• It helps maintain synchronous rotation, so the drum speed matches the engineered output of the motor and gearbox.

• It works hand‑in‑hand with other safety components like the shear pin and shaft to protect the drivetrain.

If the shaft key is worn, missing, or incorrect:

• The drum may stop turning even though the engine or motor is running.

• You may hear the motor spin freely while the drum is motionless or jerky.

• The hub might wear out or the shaft keyway can become damaged over time.

Replacing a worn key with the correct OEM Imer Workman shaft key restores positive drive and protects more expensive components from damage.

OEM vs Generic Shaft Keys

Although shaft keys look simple, they are made to exact dimensions and tolerances. Using the proper Imer Workman Mixer Shaft Key has several advantages:

• Exact size and fit – The OEM key matches the shaft and hub keyways in width and height. Too small and it will rock or shear prematurely; too large and it can deform or crack the hub.

• Correct material and hardness – A key that is too soft can deform and slip; too hard can damage the shaft or gear instead of wearing as intended.

• Proper length – The OEM key length ensures full engagement along the hub, avoiding concentrated stress on one end.

Generic keys from a hardware store may be close in size but not exact. This can lead to:

• Looseness and play in the drive.

• Premature wear of the shaft keyway.

• Difficulty assembling or disassembling components.

Because the key helps protect much more valuable parts (motor, gearbox, drum, shaft), it’s smart to use the correct Imer‑specified Workman shaft key.

Typical Symptoms of a Worn or Damaged Workman Shaft Key

If your Imer Workman mixer is having drive issues, the shaft key is one of the first small parts to check. Common symptoms that point to a key problem include:

• Motor runs but drum doesn’t turn – The engine or motor accelerates normally, but the drum does not move or moves very slowly.

• Intermittent drum movement – The drum turns under light load but stops when you add material, indicating slippage between shaft and hub.

• Grinding or clunking noises near the drive area – A loose key can rattle in the keyway, especially when the direction or load changes.

• Visible wear – When you remove the pulley or gear, you see that the key is rounded, chewed up, or badly worn on its edges.

Continuing to run the mixer with a damaged key can enlarge or deform the keyway in the shaft or the hub, turning a simple key replacement into a costly shaft or pulley replacement.

How to Identify the Correct Imer Workman Mixer Shaft Key

Imer Workman mixers use specific key sizes, and you should always match the shaft key to your exact model and serial number. To identify the correct key:

1. Check the parts manual for your Workman mixer (Workman 250, 250 II, 350, etc.). Look in the gearbox or drive section for an entry labeled “key,” “shaft key,” or something like “Key 6x6x20” (example dimension).

2. Find the key’s part number in the parts list. The parts diagram will show where it sits (on the motor shaft, gearbox input, drum shaft, etc.).

3. Use that OEM number when ordering, making sure it is described as the Workman mixer shaft key or key for your specific model.

You can also measure the old key (width, height, length) with calipers, but this is best used to confirm the part rather than to substitute for the official spec, since worn keys can be undersized.

When and Why to Replace the Shaft Key

You should replace the Imer Workman Mixer Shaft Key whenever:

• You remove a pulley or gearbox for service and see the key is rounded, worn, or damaged.

• The drum has been slipping under load and you determine the key or keyway is the cause.

• You are replacing other drivetrain components (shaft, pulley, gearbox) and want to refresh all wear items at once.

• You discover a non‑OEM key was previously installed and it does not fit tightly.

Because the key is inexpensive and easy to replace when you already have the drive disassembled, it makes sense to install a new one whenever you’ve opened up that part of the machine.

Relationship to Other Workman Drive Parts

The Imer Workman Mixer Shaft Key works as part of a small group of drive‑line hardware, including:

• Shaft – The keyed shaft that passes through the gearbox or drum support.

• Shear pin – A sacrificial pin designed to break under extreme overload to protect the gearbox; often used on Workman mixers along with the shaft key.

• Bearings – Support the shaft and keep it aligned so the key and hub remain in proper contact.

• Pulleys or gears – The parts keyed to the shaft that actually provide the drive ratio and transmit torque to the drum.

If you are experiencing drive problems, it is wise to inspect all of these components together: a worn key may indicate misalignment or bearing wear, and a broken shear pin can occur in the same overload event that damages a key.

Basic Replacement Steps (High Level)

Exact replacement steps vary by model and you should always follow the official Imer Workman manual, but the process typically includes:

1. Disconnect power – Unplug electric mixers or shut off and secure engine‑driven units.

2. Access the drive area – Remove guards and covers to reach the pulley, gearbox, or shaft where the key is located.

3. Remove the hub – Loosen set screws, remove retaining nuts, and slide the pulley or gear off the shaft.

4. Remove the old key – Use pliers or a punch to carefully remove the key from the keyway.

5. Inspect keyways – Check both shaft and hub keyways for damage; clean out debris.

6. Install the new Imer Workman shaft key – Place it squarely in the shaft keyway; it should fit snugly and sit flush or slightly proud.

7. Reinstall the hub – Align the hub keyway with the key and slide it on, ensuring a firm, aligned fit.

8. Reassemble and test – Refit guards, reconnect power, and test the mixer under light then normal load.

If the hub or shaft keyways are badly damaged, replacement of those parts may be necessary for the new key to work correctly.