Oil Seal 105×130×13 mm (TC) – SICOMA MAO – PA051

The Oil Seal PA051 is a rotary shaft seal works as the main protective component in SICOMA MAO twin-shaft mixers that use the 105 mm shaft system. It functions where the rotating shaft and the stationary housing meet, making the PA051 a crucial part of ready-mix concrete batching plants that keep everything running.

The seal design features a strong TC (Double-Lip) structure to handle demanding conditions. Its inner lip keeps the essential lubricant in place. In contrast, the outer lip acts as a shield against rough concrete dust and gritty slurry, and it ensures the bearings last even in punishing environments.

Technical snapshot:

• Application: SICOMA MAO 3000/200 Series (Specific models with 105 mm shaft sleeves)
• Nominal dimensions: 105×130×13 mm
• Inner Diameter (ID): 105 mm
• Outer Diameter (OD): 130 mm
• Thickness: 13 mm
• Type: TC (Spring-Loaded, Double Lip, Rubber Encased Metal).
• Material: NBR (Nitrile Rubber)

Abbreviations:

• TC: Rubber Coated Double Lip
• ID / OD: Inner Diameter / Outer Diameter

Why replacement matters?:

The protective shield relies entirely on the elasticity of the lips. Loss of "memory" or wear on the sealing edge lowers this defense. Once compromised:

• Grease exfiltration occurs, leaving the bearing dry.
• Abrasive cement slurry infiltrates the sensitive bearing zone.
• Friction increases dramatically, leading to the rapid destruction of the main bearing and scoring of the shaft sleeve.

In practice, neglecting a worn PA051 often escalates into a full bearing group overhaul and extended downtime for the mixer.

What to check before ordering:

The PA051 is strictly specific to SICOMA MAO revisions featuring a 105 mm shaft sleeve diameter.

It would be beneficial to have a verification of the shaft diameter (105 mm) and housing bore (130 mm) with calipers, which is a prerequisite for correct part identification.

Installation notes to consider:

• Alignment: A perpendicular seat in a clean bore is the baseline requirement.
• Application Technique: Driving the seal only by its perimeter, never striking the lip directly, is key to preserving its geometry.
• Friction Management: Dry rubber burns immediately upon start-up. Pre-lubrication of the lip and shaft with clean grease is the standard defense to ensure the seal survives the initial break-in period.
• For critical applications, installation should be carried out by a qualified maintenance technician.