CAT 078-6644 ADAPTEUR DE

CAT 078-6644 is a Caterpillar genuine hydraulic pump drive end shaft connector (drive shaft connection connector), compatible with the hydraulic pump drive system of the 3044C/3054C engine in models such as the 306E/307E excavators and 226B3/246B3 skid steer loaders. It is used in conjunction with the 078-6636 drive end seat and the 078-6641 tie belt to connect the drive shaft and the hydraulic pump input shaft, transmitting torque and ensuring coaxiality, preventing axial movement and circumferential slippage during power transmission, and is suitable for medium- and high-speed rotational conditions.

Core Parameters and Information

Item Details
Part Model: CAT 078-6644 (0786644) Drive End Shaft Connector

Structure Type: Stepped shaft connector, one end with keyway in the inner bore, one end with external thread, equipped with O-ring groove

Material: 42CrMo alloy steel (quenched and tempered HRC 28-32), surface anodized blackened, rust-proof and wear-resistant

Key Dimensions: Large end outer diameter 75 mm, small end outer diameter 65 mm, length 45 mm, keyway width 8 mm, depth 4 mm, thread M60×1.5

Performance Parameters: Rated load torque 500 N・m, coaxiality tolerance ≤0.02 mm, operating temperature -40℃ to 120℃, suitable speed ≤3000 rpm

Compatibility Standard: Complies with SAE J1962, compatible with 078-6636 seat ring, 078-6641 lacing belt

Matching Relationship: Compatible Hydraulic pump drive end for 3044C/3054C engines, compatible with 078-6636 seat ring and 078-6641 tie belt.

Compatible Models and Application Scenarios

Compatible Equipment: 306E/307E mini excavators, 226B3/236B3/246B3 skid steer loaders, compatible with 3044C/3054C engine hydraulic pump drive systems.

Application Scenarios: Installed between the drive shaft and the hydraulic pump input shaft, transmitting torque via a keyway. External threads are used to secure the locking collar, and O-ring seals prevent hydraulic oil leakage. Suitable for medium-to-high speed and variable load conditions.

Compatible Use: Used with 078-6636 drive end seat ring and 078-6641 drive end seat ring tie belt for connection and fixation of the drive end, preventing loosening that could cause vibration, abnormal noise, and component damage.

Installation and Maintenance Points:

Clean the drive shaft, connectors, and hydraulic pump input shaft surfaces, checking for burrs and rust. Ensure the connector inner bore and shaft diameter clearance is 0.02-0.05 mm.

Align the connector keyway with the drive shaft keyway and press it into place, ensuring no axial clearance. Install the 078-6636 seat ring and 078-6641 belt, tightening to 8-10 N·m.

Post-installation checks: Axial pulling of the connector should not cause movement, and circumferential rotation should not cause slippage. Run the equipment for 30 minutes; check for abnormal vibration and noise. After shutdown, re-test the connector and belt for looseness.

Maintenance: Check the connector keyway and threads for wear every 500 hours. Replace if wear exceeds 0.3 mm. Disassemble and check coaxiality every 1000 hours; replace if deviations are exceeded to prevent abnormal power transmission.