A mining contractor running a fleet of Atlas Copco ROC D7 crawler drills found one machine consistently producing less penetration rate than the others — same rock, same settings, same operator. After checking the drill steel, bit wear, flushing, and percussion pressure, a technician traced the problem to the coupling element between the rotation motor and the shank adapter housing. The element had lost 40% of its torsional stiffness due to rubber fatigue. The drill was functioning, but the energy transmission efficiency had degraded. Replacing the $65 coupling element restored penetration rate to match the fleet.
Rubber components in drill equipment are precision parts. They are not the equivalent of a washer or a gasket — they perform defined mechanical functions that directly affect drill productivity. This guide covers the rubber parts in Atlas Copco, Furukawa, and Ingersoll Rand drill equipment that require regular inspection and replacement.
Rubber Components in Rock Drills and Crawler Drills
Coupling Elements (Primary Drive Coupling)
The coupling element connects the rotation motor output shaft to the drill string through a flexible coupling. It must:
- Transmit the full rotation torque to the drill string
- Absorb the torsional shock from each percussion impact travelling back through the steel
- Accommodate slight angular misalignment between the motor shaft and the drill string axis
The coupling element is the highest-cycle rubber component on the drill — at 300 RPM rotation speed, it completes 300 torque cycles per minute, 18,000 per hour. Fatigue life of the rubber compound is the limiting factor.
Atlas Copco coupling element specifications by drill series:
COP rock drills (COP 1238, COP 1638, COP 1838, COP 2238):
The COP series uses jaw coupling elements — a six-arm rubber spider between two metal jaw hubs. Spider material is typically polyurethane on current production for improved heat resistance in the enclosed rock drill housing.
ROC crawler drills (ROC D7, ROC F9, FlexiROC series):
The main drive coupling uses a larger element than the rock drill — typically a tyre-type (donut) coupling for the engine-to-compressor drive, and a separate jaw or disc coupling for the rock drill drive train.
Boomer and Simba underground drills:
Multiple coupling points — engine to hydraulic pump train, rock drill drive coupling. Each position may use a different coupling type.
Inspection and replacement:
Check coupling elements at every 250-hour service on production drilling equipment. Replace when:
– Visible cracking penetrating more than 30% through the element cross-section
– Any element arm compression set exceeding 15% (measure against new part height)
– After any major jam or drill string stall incident (overload condition)
Rubber Buffers (Percussion Dampeners)
Rubber buffers in rock drills absorb the rebound energy from each percussion impact. Every time the piston strikes the drill steel, the percussion energy travels down the steel and partially reflects back. Without absorption, this reflected energy causes the piston to bounce unpredictably, reducing penetration rate and accelerating piston wear.
Buffer location varies by rock drill model:
– Front buffer: Between the drill steel chuck and the front head — absorbs direct rebound
– Rear buffer: Between the piston housing and the backhead — absorbs the rebound that reaches the rear of the drill
– Side buffers (some models): Constrain lateral movement of the drill steel
Buffer rubber compound must combine good dynamic damping (to absorb rebound energy) with high fatigue life (each percussion stroke is a full compression-rebound cycle at 35–60 Hz frequency). Natural rubber with specific damping additives is standard; synthetic compounds are used in high-temperature applications.
Replacement indicators:
– Buffer height reduced more than 10% from specification (measured with machine off, no percussion pressure)
– Visible cracking across the full buffer face
– Penetration rate reduction that cannot be explained by bit wear or rock formation
Vibration Isolation Mounts (Drill Rig)
On crawler drills and surface drill rigs, the drill frame mounts to the carrier through vibration isolation mounts. These serve two functions:
- Protect the carrier structure from the high-frequency vibration generated by percussion drilling
- Prevent percussion vibration from being transmitted to the operator station
These mounts typically require replacement at 3,000–5,000 hours — less frequently than coupling elements and buffers, but the consequences of failure are structural (carrier frame fatigue cracking) rather than just productivity loss.
Dust Seal / Rod Seal
The drill rod seal prevents cuttings and water from entering the rock drill housing from the front. Failed dust seals allow abrasive contamination into the drill housing, accelerating chuck bushing and front head bore wear. Replace at any sign of contamination entering the drill housing, or proactively at every 500-hour service.
Atlas Copco Portable Compressor Rubber Parts (XAS/XAVS Series)
Atlas Copco’s XAS and XAVS portable compressors use rubber components at two main locations:
Engine-to-Compressor Coupling
The coupling between the diesel engine and the screw compressor element transmits full engine torque while absorbing the pressure-pulse vibration from the screw compressor. This is typically a tyre-type coupling on larger units (XAS 186, XAS 375, XAVS 375).
Common failure mode: The tyre element degrades gradually — the outer rubber cracks from ozone aging, the internal construction fatigues from torque cycling. The tyre can appear sound externally while the internal layers are separating. When tyre failure occurs suddenly, the engine and compressor shafts can contact, causing hub damage.
Inspection: Remove the coupling guard every 500 hours and inspect the tyre outer surface and side walls. Squeeze the tyre by hand — it should feel uniformly firm, not soft or collapsed at any section.
Compressor Mounting Isolators
The screw compressor element mounts to the chassis through rubber isolators that prevent compressor vibration from transmitting to the trailer frame and tow vehicle. Worn compressor isolators cause trailer frame cracking and increased vibration in the hydraulic line connections.
Furukawa Rock Drill Rubber Parts
Furukawa drills (HCR, CRF series, and the legacy F series) use rubber components in similar locations to Atlas Copco but with different specifications. Key differences:
- Furukawa HCR series uses a different coupling geometry than Atlas Copco COP series — parts are not interchangeable
- F9 and F22 legacy models use rubber buffer designs that are no longer available from Furukawa directly — aftermarket cross-referencing from measurements is required for older machines
- Furukawa impact rate (blows per minute) is typically higher than equivalent Atlas Copco models, which means higher cycle count on rubber components and correspondingly shorter replacement intervals
For Furukawa F-series obsolete part cross-references, Babacan Group’s technical team can manufacture from sample components or drawings. Contact us with your drill model and the component you need.
Ingersoll Rand Drill Rubber Parts
Ingersoll Rand’s Rock Drill division (now part of Epiroc after corporate restructuring) produced the CM and ECM series surface drills and the Solo and Stopemaster underground drills. Many of these machines remain in active service.
IR rubber component considerations:
– Coupling elements for older IR/Ingersoll-Rand drills often use imperial dimensions — verify bore dimensions before ordering
– CM series surface crawler drills used a large tyre coupling at the power pack that is still serviceable from quality aftermarket suppliers
– Epiroc now supplies parts for legacy IR drills — compare Epiroc pricing against aftermarket before assuming OEM is the only option
Sourcing Drill Rubber Parts
The challenge with drill rubber parts is that the machines are often in remote locations — mining sites, quarries, tunnel projects — where parts availability is critical to keeping the work schedule on track.
Babacan Group supplies drill rubber parts to mining contractors and equipment dealers across 84 countries. We stock the most common Atlas Copco, Furukawa, and Ingersoll Rand coupling elements and buffers. For less common references, production lead time is typically 2–3 weeks from order confirmation.
Our drill spare parts range includes:
– Coupling elements for COP, ROC, and Boomer series drills (jaw, disc, and tyre types)
– Percussion buffers for all major rock drill models
– Vibration isolation mounts for crawler and surface drills
– Compressor coupling elements for XAS and XAVS series
– Furukawa HCR and F-series equivalents
For part cross-references on your specific Atlas Copco, Furukawa, or Ingersoll Rand model, request a quote with your drill model and serial number.
Key Takeaways
-
Coupling elements affect productivity, not just reliability: A worn coupling element reduces energy transmission efficiency before it fails completely. If penetration rate is down and everything else checks out, the coupling element is a low-cost first check.
-
Atlas Copco COP and ROC series use different coupling types: Don’t cross-reference between rock drill drive and main rig drive positions. They have different size and type requirements.
-
Rubber buffer wear affects percussion efficiency: Buffer height loss greater than 10% changes the percussion kinematics. Measure buffers at service intervals, don’t just inspect visually.
-
Tyre couplings on XAS compressors fail internally before showing external signs: Schedule coupling guard removal and inspection, not just visual walk-around checks.
-
Furukawa F-series obsolete parts are available from specialized aftermarket manufacturers: Legacy equipment isn’t a dead end — manufacturers like Babacan Group can produce from samples and measurements.
Contact Babacan Group’s technical team for Atlas Copco, Furukawa, and Ingersoll Rand drill rubber part specifications and sourcing.
Word Count: ~1,500 words