Bitzer 4TF - User Manual

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KW-530-1

Wartungsanleitung

Maintenance Instruction

Instructiondemaintenance

Reparatur und Überholung von

Verdichtern für Fahrzeugeinsatz

Typen: 4TF(Y), 4PF(Y), 4NF(Y)

Inhalt:

1. Allgemeines

2. Reparatur

2.1 Fehlerdiagnose

2.2 Austausch der Magnetkupplung

2.3 Austausch der Wellenabdichtung

2.4 Austausch Lagerdeckel / Ölpumpe

2.5 Einstellung des Axialspiels

2.6 Austausch des Überströmventils

2.7 Austausch Ventilplatte / Zylinderkopfdichtung

2.8 Austausch der Leistungsregelung

3. Überholung

3.1 Demontage des Verdichters

3.2 Prüfung auf Schäden und Verschleiß

3.3 Toleranzbereiche

3.4 Zusammenbau des Verdichters

Anhang Schraubenanzugsmomente

Repair and Overhaul of Compressors for

Vehicle Applications

Types: 4TF(Y), 4PF(Y), 4NF(Y)

Contents:

1. General

2. Repair

2.1 Fault diagnosis

2.2 Exchanging the magnetic clutch

2.3 Exchanging the shaft seal

2.4 Exchanging the bearing cover / oil pump

2.5 Setting the axial play

2.6 Exchanging the relief valve

2.7 Exchanging the valve plate / cylinder head gasket

2.8 Exchanging the capacity control

3. Overhaul

3.1 Disassembling the compressor

3.2 Checking for damage and wear

3.3 Tolerance range

3.4 Assembling the compressor

Appendix tightening torques

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This document is a maintenance and overhaul manual for Bitzer reciprocating compressors, specifically models 4TF(Y), 4PF(Y), and 4NF(Y), designed for vehicle applications. It provides comprehensive instructions and guidelines for repair, overhaul, and troubleshooting, ensuring reliable operation and extended service life.

Function Description:

The Bitzer reciprocating compressors covered in this manual are open-type compressors used in vehicle refrigeration systems. They are designed to compress refrigerant, facilitating its circulation within the refrigeration cycle. The manual details the internal components, including the crankshaft, pistons, connecting rods, shaft seal, roller bearings, oil pump, and various valves (oil regulating, relief, suction, and pressure equalizing). The compressors feature a magnetic clutch for engaging and disengaging the drive, and some models incorporate capacity control for efficient operation under varying load conditions.

Important Technical Specifications:

While specific performance data is not extensively detailed, the manual provides critical technical specifications related to maintenance and assembly:

Axial Play of Crankshaft: Must be within a tolerance range of 0.3 to 0.5 mm. This is a crucial parameter for proper bearing function and can be adjusted using gaskets of varying thicknesses (0.5, 0.75, 1.0 mm).
Oil Pressure: For models without an oil pressure switch, the oil pressure should be manually checked during routine maintenance. It must be at least 1.4 bar at an operating temperature of minimum 40°C and 1500 rpm.
Relief Valve Opening Pressure: The set differential pressure for the relief valve to open is 26 bar, acting as a safety device.
Tightening Torques: A detailed appendix provides tightening torques for various connections, categorized by normal fixings (with and without flat gaskets, and by serial number range) and special fixings (oil pump, shut-off valves, magnetic plug, connecting rod screws). For example, normal fixings with flat gaskets (from serial no. 467...) range from 16 Nm (M6) to 125 Nm (M12). Special fixings like connecting rod screws (M6, 10.9) require 16 Nm, and the oil pump (M8) requires 23 Nm.
Cylinder Bore Maximum Permissible Measure: 55.015 mm for 4NF and 60.015 mm for 4TF/4PF.
Maximum Permissible Bearing Play: Shaft-bearing and connecting rod-eccentric shaft (4TF) are 112 µm. Connecting rod-piston pin (4TF) is 19 µm. Connecting rod-shaft journal (4PF/4NF) is 72 µm. Connecting rod-piston pin (4PF/4NF) is 26 µm.

Usage Features:

The manual emphasizes that Bitzer compressors are manufactured with high quality and provide reliable operation and a long service life when design manual and operating instructions are followed. It addresses common operational problems, such as safety cut-outs, insufficient capacity, insufficient lubrication, and component damage, providing diagnostic steps and corrective measures. The capacity control feature, when present, allows for efficient operation by adjusting the compressor's output based on demand. The magnetic clutch enables quick engagement and disengagement of the compressor drive.

Maintenance Features:

The manual is a comprehensive guide for maintaining and overhauling the compressors:

Fault Diagnosis: A detailed section helps identify the root causes of operational faults and damage, such as low suction pressure, high discharge/condensing pressure, high discharge gas/oil temperature, defective valves, and cylinder head gasket leaks.
Repair Procedures: Step-by-step instructions are provided for replacing key components, including the magnetic clutch, shaft seal, bearing cover/oil pump, valve plate/cylinder head gasket, and capacity control.
Axial Play Adjustment: Critical for crankshaft longevity, the manual details how to measure and adjust axial play using different gasket thicknesses.
Overhaul Procedures: For complete overhauls, instructions cover disassembly, checking for damage and wear, identifying tolerance ranges for various components (bearings, cylinder bore), and reassembly.
Component Inspection: Guidelines are given for inspecting cylinder liners (honing pattern visibility), shaft (cleanliness of bearing surfaces and oil channels), oil pump (freedom of movement for gears), and valve plates (condition of working valves and reeds).
Safety Notes: Crucially, the manual highlights safety precautions, stating that all work must be performed by qualified personnel and that working on a pressurized compressor can lead to serious injuries.
Important Notes: Bitzer disclaims warranty for damage caused by incorrect handling. It also advises against oiling asbestos-free gaskets to prevent leaks.
Part Replacement Recommendations: After a long running time, it is generally recommended to replace parts such as roller bearings, bearing cover, connecting rods/pistons, valve plates, shaft seal, and oil pressure regulating valve. Relief valves that have operated must also be replaced.
Cleaning and Lubrication: Emphasizes thorough cleaning of all parts and oiling moving parts and sliding surfaces with clean refrigeration oil during reassembly.