AERIALCAT Engine and Related Components

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2 Drivers Side Engine and Related Parts AERIALCAT Engine and Related Components Washer Fluid Reservoir 3 Gallon Engine Coolant Reservoir Air Compressor Governor AC Compressor Air Filter Spark Arrestor ECU Electronic Control Unit Power Steering Fluid Reservoir Air Compressor System Fuel Filter ABS Modulator Pre-Trip Inspection Overall appearance and condition All lights, signals, and reflectors Windows and mirrors Compartment and cab doors Equipment attached Engine fluids Engine belts Engine components Fuel system Pumping equipment Suspension component Tire and wheels Drive line / Drive train Frame Brake systems Air brake leakage test Steering components All gauges Safety devices Apparatus logs 51

3 ELECTRONIC CONTROL UNIT (ECU) AERIALCAT Engine and Related Components The ECU contains the microcomputer which is the brain of the control system. Fan Clutch Solenoid The ECU receives and processes information defining: Shift selector Throttle position Sump retarder temperature Engine speed Turbine speed Transmission output speed. The ECU uses the information to: Control transmission solenoids and valves Supply system status Provide diagnostic information. Each ECU has a date code stamped on the label which is attached to the outer case of the ECU. This is the date when the ECU passed final testing. This date is commonly used to denote the change configuration level of the ECU. It is normal for the ECU date displayed electronically to be a few days prior to the date shown on the label. 52

4 A/C Refrigerant Flow System Overview Compressor and Clutch The system uses a Model TM31 compressor. It is mounted on the engine and is belt -driven through an electromagnetic clutch which acts to engage (turn ON) or disengage (turn OFF) the compressor in response to the air conditioning system controls. When engaged, the clutch armature assembly is magnetically drawn to the pulley assembly on the compressor shaft, thereby engaging the clutch and allowing the drive belt to drive the compressor. A pressure relief valve on the compressor offers protection to the compressor in extreme high pressure conditions. While the high pressure/high temperature liquid refrigerant is present on the condenser side of the evaporator expansion valve, the suction side of the compressor is reducing the pressure in the evaporator. The pressure differential causes a measured amount of the high pressure liquid refrigerant to flow through the expansion valve and enter the low pressure evaporator as a low temperature liquid. The valve is the dividing line between the high pressure side of the system and the low pressure side of the system. Within the evaporator coil, the lower pressure permits the liquid refrigerant to boil or evaporate, changing its state from a liquid to a low pressure/low temperature vapor; and absorbing heat from the evaporator core and the air surrounding it. Cooling and dehumidifying of the cab s interior takes place as the refrigerant vapor passes through the evaporator s finned tubes and absorbs heat from the cab air pulled through the evaporator coil by the system blower. Humidity condenses on the external surfaces of the cooled evaporator fins and is channeled (drained) out of the evaporator housing through drain tubes. The refrigerant exits the evaporator outlet as a low pressure/low temperature vapor. The compressor repressurizes the refrigerant causing it to again become a high pressure/high temperature vapor that is pumped to the condenser, where the cycle is repeated. 53

5 A/C Refrigerant Flow System Overview The refrigerant cycle, consists of four phases: compression, condensation, expansion, and evaporation. Consider the starting point at the compressor. When any air conditioning position is selected, the clutch assembly mounted to the front of the compressor becomes engaged. When engaged, the clutch armature assembly is magnetically drawn to the pulley assembly on the compressor shaft, thereby engaging the clutch and driving the compressor. The suction side of the compressor draws low pressure refrigerant vapor (5 to 50 psi) from the low side of the system, coming from the evaporator. The compressor then compresses the refrigerant vapor and discharges it at increased temperature and pressure (120 to 300 psi) through the high side line which connects the compressor to the condenser under normal conditions. An internal lubricating system uses the suction side intake crankcase pressure differential to coat internal parts with a thin film of oil. This lubrication also travels along with the refrigerant throughout the air conditioning system to lubricate various system components. High pressure/high temperature refrigerant vapor from the compressor enters at the top of the condenser, circulates down through the coils and exits at the bottom of the condenser as high pressure/high temperature refrigerant liquid. As the vapor condenses (changes state), some of its heat is released to the coils and fins of the condenser. This heat is continually carried away by the outside air which passes over the external fin surfaces as it flows through the condenser. The efficiency of the condenser operation is affected by air flowing through the condenser. For this reason, it is important that the cooling fans be operating properly, and that the condenser cooling fins remain free of airborne contamination (leaves, insects, dirt, etc.) which can block the fins and cause system temperatures to run higher than normal. When operating properly, the condenser acts as an efficient heat exchanger, containing refrigerant vapor in approximately two-thirds of the coil and condensed refrigerant liquid in one-third portion. The condenser passes high temperature/high pressure liquid refrigerant to the receiver/drier. The receiver/drier absorbs or separates any moisture from the refrigerant using a drying agent (desiccant). The receiver/drier also includes a high/low pressure switch. The high temperature/ high pressure liquid refrigerant is then passed to the expansion valves. 54

6 Washer Fluid Reservoir Power Steering Fluid Reservoir 3 Gallon Engine Coolant Reservoir This "Fuel Purifier" is based on surface tension principle and rotational fluid motion also known as Cyclone Separation Since diesel and water have different surface tension as well as density, when a mixture of diesel and water is spread over a large area water droplets and large solids will separate from the fuel. The clean fuel is drawn out of the unit and into the primary fuel filter of your system. Water and contamination is drained from the bottom of the unit. This process continues as long as the engine fuel pump is operating. 55

7 Cummins ISM 500 IS - Interactive System M - Engine Model Designation Advertised Brake Horsepower Air Compressor Governor Engine Oil Level Check Engine Oil Fill 56

8 Diesel Engines vs. Gasoline Engines AERIALCAT Engine and Related Components Cummins ISM 500 -In theory, diesel engines and gasoline engines are quite similar. They are both internal combus-tion engines designed to convert the chemical energy available in fuel into mechanical energy. This mechanical energy moves pistons up and down inside cylinders. The pistons are connected to a crankshaft, and the upand-down motion of the pistons, known as linear motion, creates the rotary motion needed to turn the wheels of a car forward Both diesel engines and gasoline engines covert fuel into energy through a series of small explosions or combustions. The major difference between diesel and gasoline is the way these explosions happen. In a gasoline engine, fuel is mixed with air, compressed by pistons and ignited by sparks from spark plugs. In a diesel engine, however, the air is compressed first, and then the fuel is injected. Because air heats up when it's compressed, the fuel ignites. The diesel engine uses a four-stroke combustion cycle just like a gasoline engine. The four strokes are: Intake stroke -- The intake valve opens up, letting in air and moving the piston down. - Compression stroke -- The piston moves back up and compresses the air. Combustion stroke -- As the piston reaches the top, fuel is injected at just the right moment and ignited, forcing the piston back down. Exhaust stroke -- The piston moves back to the top, pushing out the exhaust created from the combustion out of the exhaust valve. Remember that the diesel engine has no spark plug, that it intakes air and compresses it, and that it then injects the fuel directly into the combustion chamber (direct injection). It is the heat of the compressed air that lights the fuel in a diesel engine. In the next section, we'll examine the diesel injection process. 57

9 Turbocharger/ Air Flow Air sent to front of the engine to be cooled before entering engine Cool air sent back to engine Pressurized air leaving turbocharger Spark Arrestor air entering turbocharger Air Filter Air Intake 58

10 Variable Geometry Turbocharger AERIALCAT Engine and Related Components Air after the Air Filter entering the First Stage Turbo Pressurized Air to be cooled Turbocharger Control Valve Turbocharger (exhaust) Intake side Turbocharger A turbocharger consists of a turbine and a compressor linked by a shared axle. The turbine inlet receives exhaust gases from the engine exhaust manifold causing the turbine wheel to rotate. This rotation drives the compressor, compressing ambient air and delivering it to the air intake manifold of the engine at higher pressure, resulting in a greater amount of the air and fuel entering the cylinder. The objective of a turbocharger is the same as a normal supercharger; to improve upon the size-to-output efficiency of an engine by solving one of its cardinal limitations. A naturally aspirated automobile engine uses only the downward stroke of a piston to create an area of low pressure in order to draw air into the cylinder through the inlet valves. Because the pressure in the cylinder cannot go below 0 psi (vacuum), and because of the relatively constant pressure of the atmosphere (about 15 psi), there ultimately will be a limit to the pressure difference across the inlet valves and thus the amount of airflow entering the combustion chamber. This ability to fill the cylinder with air is its volumetric efficiency. Because the turbocharger increases the pressure at the point where air is entering the cylinder, and the amount of air brought into the cylinder is largely a function of time and pressure difference, more air will be forced in as the inlet manifold pressure increases. The additional air makes it possible to add more fuel, increasing the power and torque output of the engine, particularly at high engine rotation speeds. Because the pressure in the cylinder must not go too high to avoid pre-ignition and physical damage, the intake pressure must be controlled and this is done by a wastegate, which controls boost by routing some of the exhaust flow away from the exhaust side turbine. This controls shaft speed and regulates boost pressure in the inlet tract. The application of a compressor to increase pressure at the point of cylinder air intake is often referred to as forced induction. Centrifugal superchargers operate in the same fashion as a turbo; however, the energy to spin the compressor is taken from the rotating output energy of the engine's crankshaft as opposed to exhaust gas. Superchargers and turbochargers use output energy from an engine to achieve a net gain, which must be provided from some of the engine's total output. In the case of superchargers, either directly or from a separate smaller engine, perhaps electrically driven from the main engine's generator. 59

11 Variable Geometry Turbocharger / Control Valve Filtered Air Pressurized (heated) air going to the front of the engine to be cooled Turbocharger Control Valve Exhaust Air Intake Exhaust Stage Turbocharger Intake Stage Turbocharger 60

12 Auxiliary Engine Cooler AERIALCAT Engine and Related Components Coolant hose Radiator Fill Radiator Auxiliary engine cooler Immersion Type Control the temperature of coolant in the apparatus engine during pumping operations. 2 types of auxiliary coolers: Marine type and Immersion: Marine - is inserted in 1 of the hoses used in the engine cooling system in such a way that the engine coolant must travel thru it as it circulates thru the system. Immersion - tubing immersed in the coolant absorbs heat & dissipates it in water from the pump. Immersion Type 61

13 Alternator Alternator is located in the front on Officer side 270 AMP Alternator Overview of the Charging System The Charging system is an important part of the electrical system. It provides electrical current for the lights, the radio, the heater, the engine s electrical systems, and other electrical accessories. It also maintains the batteries in a charged state, recharging them as necessary. In order to properly service the charging system, you need to understand how it operates. The charging system has three main components: the alternator, the voltage regulator, and the batteries. The alternator generates electrical power to run accessories and to recharge the batteries. It is normally driven by a belt located off the crankshaft. Mechanical energy from the crankshaft is converted by the alternator into electrical energy for the batteries and accessories. The voltage regulator acts as an electrical traffic cop to control alternator output. It senses when the batteries need recharging, or when the vehicle s electrical needs increase, and adjusts the alternator s output accordingly. The batteries are a reservoir of chemical electrical power. Their primary purpose is to crank the engine. They also supply power to vehicle accessories when the electrical load is too great for the alternator alone. 62

14 Starter Starter 4.1 An Overview of the Starting System:The starting system converts electrical energy from the batteries into mechanical energy to turn the engine over. A malfunction within the starting system will make it difficult to get the engine running. In order to properly service the starting system, you need to understand how it operates. The starting system has five main components: the ignition switch or start button, a neutral safety switch (an option on some vehicles), the starter solenoid, the starter motor, and the batteries. Solenoid is located below the no step plate above the transmission When the start button is pushed, electricity flows from the batteries to the starter solenoid. Some vehicles are equipped with a neutral safety switch. If the vehicle is in gear when the key is turned, the neutral safety switch blocks the signal to the batteries, so the engine doesn t start cranking. Otherwise, the vehicle could jump forward or backward when the key is turned. The starter solenoid is an electromagnetic switch mounted on the starter motor. When coils inside the solenoid are energized by electricity, they create a magnetic field which attracts and pulls a plunger. Attached to one end of this plunger is a shift lever. The lever is connected to the drive pinion and clutch assembly of the starter motor. The starter motor is a small but powerful electric motor that delivers a high degree of power for a short period of time. When the starter motor is energized it engages the flywheel ring gear and produces torque, which turns the flywheel and cranks the engine. 63

15 Hydraulic Filters The hydraulic system contains a pressure and a return line filter. The filter system is equipped with a visual condition indicator and a bypass that functions if the filter becomes clogged. When the indicator shows the need, the element should be replaced. The pressure and return filters are generally located on the driver s side frame rail behind the compartment directly behind the cab. Hydraulic Pressure Filter High Pressure Filter on the pump side of the system. Return Filter The hydraulic system contains a pressure and a return line filter. The filter system is equipped with a visual condition indicator and a bypass that functions if the filter becomes clogged. When the indicator shows the need, the element should be replaced. The pressure and return filters are generally located on the driver s side frame rail behind the compartment directly behind the cab. 64

16 AIR COMPRESSOR AIR COMPRESSOR The air compressors lines go to air tanks that are used to run the horn and to hold back the spring in the brake cans The Air Tanks have a regulator which monitors the air pressure inside the tank. Once the air pressure builds it sends a signal to the air compressor to turn off. 65

17 The Sheppard M-Series Integral Power Steering Gear provides full-time hydraulic steering. Power Steering Gear Box Drag Link Pittman Arm What is a Power Steering Pump? The pump is the heart of the hydraulic steering system. It converts the rotational energy supplied by the engine into hydraulic energy, flow and pressure, for use by the steering gear. Theory of Operation All pumps function by creating a partial vacuum at the inlet, which causes atmospheric pressure to force fluid into the pump from the reservoir. The pump then pushes this fluid into the system for use. The fluid is used to power the steering gear. Pump output flow relates to steering gear speed and pump output pressure relates to steering gear force (work). Cut Away Power Steering Gear Box 66

18 When the engine is running there is constant low pressure oil flow through the steering gear. This constant oil flow provides an instant response and absorbs road shock to help eliminate steering wheel kick. Pressure is equal throughout the steering gear; however, care should be used when towing or moving a vehicle where the engine or hydraulic supply pump is not running. If sudden loss of pressure occurs during normal driving, the parts are designed to provide mechanical backup steering so that the vehicle may be safely steered to the side of the road. There are 3 Power Steering Gear Box on the Aerialcat, this is the Tiller Power Steering Gear Box Only enough manual effort to overcome the torsion bar and turn the rotary valve is required. The actuating shaft (1) is connected to the steering column and is centered within the rotary valve by a torsion bar. The rotary valve shaft is threaded into the piston with ball threads (2) and travels within the piston on steel balls. Rotating the input shaft causes high pressure fluid to build up on one end of the piston. This higher pressure causes the piston to move in the bore of the gear housing. The sector shaft (3) is engaged to a rack gear (4) machined into one side of the piston. Piston rack movement causes sector shaft and pitman arm rotation. When steering shaft rotation stops, the actuating valve returns to its neutral position. Relief valve plungers or adjustable stops are used in the bearing cap and cylinder head. When the plungers are adjusted properly, they will unload the hydraulic system if the wheels are in a full turn to either direction. 67

19 The Sheppard M-Series Integral Power Steering Gear provides full-time hydraulic steering. ABS Computer Drag Link Captain side Power Steering Gear Box (Secondary) Pittman Arm Cab Hydraulic Lift Maintenance Tips Never high-pressure wash or steam clean a power steering pump while off the vehicle. Doing so could force contaminants inside the pump and cause it to malfunction. Regularly check the fluid and the fluid level in the power steering reservoir. Encourage drivers to report any malfunctions or accidents which could have damaged steering components. Do not attempt to weld any broken steering component. Replace the component with original equipment only. Do not cold-straighten, hot straighten, or bend any steering system component. Always clean off around the reservoir filler cap before you remove it. Prevent dirt or other foreign matter from entering the hydraulic system. Investigate and correct any external leaks, no matter how minor. Replace reservoir filters according to requirements. If you feel the vehicle is developing excessively high hydraulic fluid temperatures, consult with your vehicle manufacturer for recommendations. 68

20 Preventive Maintenance Guidelines Drain reservoir and replace filter. (1x/year- Hlghway, 2xJyeru- Severe Duty} nghten hose clamps and inspect all hydraulic hoses and connections for leakage. Bleed air from the system, if required. (2xlyear) Routinely check oil level. See list of approved hydraulic fluid on following page. Inspect U-joint and pinch bolts. Torque to approved specification. {4xtyear) If equipped with grease fittings. lube intermediate column U-joints and slip joint. {At each lube cycle) Lubrication guidelines for tie rod and draglink ends. Highway (Every 20 (XX) m ;s) PICk-up..Oelrvety (2x.trron:h) Hea.y 0\r.y (Every 500 ro.. ~) Severe Ou:y (EverJ250 l'o.i's) se llam opere~ted ;r~se ; un. Replenish lube under din and water seal. (2xlyean Lubricate at trunnion grease fitting with hand operated gun only. (At each lube cycle) nghten ptt.man am1 connection to approved torque specification. (~xtyear) Check cotter pin at slotted nut on all tie rod and draglink ends. Check nut torque and replace cotter pin, if missing, (At each ube eye e) KME 2010 AERIAlCAT 69 LA. COUNTY 100' TRACTOR DRAWN AERIAl

21 Allison Transmission Emergency Vehicle Series (EVS) 4500 Fuel Restrictor Module Allison EVS 4500 Automatic Transmission Solenoids Hydraulic Pump Exhaust Fuel Restrictor Module Sends a signal to cab (light) when it senses a block in fuel system 70

22 HYDRAULIC SYSTEM AERIALCAT Engine and Related Components Steel tubing and high pressure hydraulic hoses are used throughout the hydraulic system. Easily accessible strainers and filters are installed in the system to maintain fluid cleanliness. A 28 gallon capacity hydraulic oil reservoir, complete with dipstick to check oil levels, provides a sufficient supply of hydraulic oil for the systems operations. Other components that makeup the hydraulic system are the power-take-off hydraulic pump, emergency hydraulic pumps, and hydraulic swivel. Hydraulic Pump for the AerialSeen from above POWER TAKE OFF HYDRAULIC PUMP The power-take-off driven hydraulic pump is equipped with an electric shift power-take-off that drives the main hydraulic pump. The hydraulic pump provides sufficient pressurized hydraulic fluid to meet all the operational requirements of the TDA ladder and outrigger system. Power Take Off Hydraulic Pump for the Aerial Seen from Below the Aerialcat Transmission Power Steering lines for Tiller Axle pump 71

23 HYDRAULIC SYSTEM Hydraulic Oil Filter Pressure side EPU Emergency Pump Unit Other components that makeup the hydraulic system are the power-take-off hydraulic pump, emergency hydraulic pumps, and hydraulic swivel. EPU Emergency Pump Unit, used to operate aerial in event of a power failure Solenoid (Relay) EMERGENCY PUMPS The TDA Aerialcat is equipped with an emergency hydraulic system capable of providing limited ladder operation in the event the main hydraulic pump or vehicle engine fails. The pump is powered by 12VDC integral electric motor; and operates separately from the main hydraulic pump. This pump has an operation time of seven minutes after which they must cool for 1-1/2 hours. It is, therefore, important that during emergency operations these pumps be used sparingly and only when necessary ladder movements are required. 72

24 Brake System An Anti-Skid Braking System (ABS) is provided to improve braking control and reduce stopping distance. This braking system is fitted to axles and all electrical connections are environmentally sealed, water weatherproof, and vibration resistant. The system constantly monitors wheel behavior during braking. Sensors on each wheel transmit wheel speed data to an electronic processor that senses approaching wheel lock and instantly modulates brake pressure up to 5 times per second to prevent wheel lock-up. Each wheel is individually controlled. To improve service trouble shooting provisions in the system for an optional diagnostic tester is provided. The system tests itself each time the vehicle is started and a dashmounted indicator light will go out once the vehicle is moving above 4 mph. To improve field performance, the system is equipped with a dual circuit design. The system circuits are configured in a diagonal pattern. Should a malfunction occur, that circuit reverts to normal braking action. A warning light signals malfunction to the operator. The system consists of a sensor clip, sensor, electronic control unit, and solenoid control valve. The sensor clip holds the sensor in close proximity to the tooth wheel. An inductive sensor consisting of a permanent magnet with a round pole pin and coil produces an alternating current with a frequency proportional to wheel speed. This sensor is sealed, corrosion-resistant and protected from Electro-magnetic interference. The electronic control unit monitors the speed of each sensor wheel slip. The system also controls application of the auxiliary engine exhaust or drive line brakes to prevent wheel lock. 73

25 Jake Brake controls On/Off, Hi/Med/Low The Jacobs Engine Brake is a device that mounts on, or within, the engine overhead. It changes the timing of the engine exhaust valves, turning the engine into a giant air compressor. The resulting retarding power is proportional to engine RPM. It is typically used to enable safer vehicle speed control in several driving conditions, from flatlands to steep downhill descents. Diesel Engine Without Engine Brake (1) The intake valve opens and air is forced into the cylinder by boost pressure from the turbocharger. With a Jacobs Engine Brake (1A) The intake valve opens and air is forced into the cylinder by boost pressure from the turbocharger. (2) Air is compressed by the engine piston. The energy required to compress this air is produced by the vehicle's driving wheels. (2A) Air is compressed to approximately 500PSI by the engine piston. The energy required to compress this air is produced by the vehicle's driving wheels. Near top dead center, the Jacobs Engine Brake opens the exhaust valves, venting the high pressure air and dissipating the stored energy through the exhaust system. 74

26 Diesel Engine Without Engine Brake (3) When the piston passes over top dead center and begins its downward stroke, the energy is returned to the piston (and to the driving wheels). Essentially no energy is absorbed and no net retarding work is done. With a Jacobs Engine Brake (3A) On the downward stroke, essentially no energy is returned to the piston (and to the driving wheels). There is a loss of energy. This loss is how the retarding work is done. (4) Normal exhaust stroke. (4A) Normal exhaust stroke. Always check road conditions prior to the use of Jake brake. Skidding & loss of control can occur. Make sure you have the correct setting for the road conditions. 75