TYPICAL EXAMPLES OF OPERATION : 950K, 962K, 966K, 972K and 980K Wheel Loaders

Operation Information

Carry a loaded bucket low so that the operator has good visibility and so that the machine has good stability.

Clean the work area during waiting periods and level the work area during waiting periods. Maintain traction by avoiding excessive downward pressure on the bucket. Travel in reverse when you carry a load down a steep incline. Travel forward when you go uphill. When you are working in hard material, use bucket teeth or bolt-on cutting edges. Make sure that the bucket that is being used is appropriate for the work that is being performed. Exceeding the machine limits will reduce the service life of the machine.

Bulldozing

Keep the bottom of the bucket parallel to the ground when you are bulldozing.

Dumping

To control dumping, move the tilt control lever to the DUMP position. Then, return the tilt control lever to the HOLD position. Repeat this procedure until the bucket is empty. Dump the bucket when the wind is moving toward the front of the machine. This will help to keep dust away from the engine. This will also help to maintain visibility. To achieve the maximum angle for dumping, use the bucket stops.

NOTICEStriking the stops unnecessarily and repetitively can result in accelerated wear and high maintenance cost of the loader linkage.

Excavating with Bucket

1. Lower the bucket to the ground. Position the bucket for a slight digging angle.

2. Apply downward pressure to the bucket as the loader starts forward. Return the lift lever to HOLD when sufficient penetration is obtained.

3. Maintain level cuts while you move forward by raising the bucket and lowering the bucket.

4. When the bucket is loaded, tilt the bucket backward against the stops. Carry the loaded bucket for approximately 40 cm (15 inch) above the ground when you move to the dump area.

CAUTION: Excavating large rocks or firm hard material until the rear of the machine rises up applies great force on the loader linkage and areas of the chassis. Repeating such operation an excessive amount will result in bending or tearing of the loader linkage or the chassis, and increase repair costs.

Using the corner of a bucket to excavate large rocks or firm hard material applies uneven force on the loader linkage. Repeating such operation an excessive amount will result in bending or tearing of the loader linkage, and increase repair costs.

Loading with a Bucket from a Stockpile

1. Position the bucket parallel to the ground. The bucket should barely skim the ground. Drive the bucket straight into the pile.

2. Move the bucket lift lever to the detented RAISE position as the forward movement slows. Return the bucket lift lever to the HOLD position for additional crowding power.

3. To load a heaped load, operate the bucket tilt lever back and forth. This action is called pumping.

4. When the bucket is loaded, move the bucket tilt lever to the TILT BACK position.

5. When the bucket tilt lever is released to the HOLD position, the bucket will rise.

6. Raise the bucket high in order to pass over the material that is being loaded. Shift the transmission into REVERSE.

7. Carry the loaded bucket approximately 40 cm (15 inches) above the ground level.

8. When you reach the dump area, move the bucket lift lever to the detented RAISE position. The lift kickout will automatically return the bucket lift lever to the HOLD position.

Bucket Loading Hauling Units

1. To reduce the loader turning and the travel distance, position the hauling unit at an angle to the material that is being loaded.

2. The travel distance should be long enough so that the bucket can reach the lift height without slowing the movement of the loader.

3. Position the loader in order to dump the load in the center of the hauling unit body. If the length of the hauling unit body is two times the length of the bucket, load the material into the hauling unit body from the front to the rear.

4. Push the bucket tilt lever forward in order to dump the load from the bucket.

5. Shake the bucket in order to loosen sticky material. Move the bucket tilt lever back and forth in quick motions. Allow the tilt arms to strike the stops.

NOTICEStriking the stops unnecessarily and repetitively can result in accelerated wear and high maintenance cost of the loader linkage.

6. Move the bucket tilt lever to the TILT BACK detent position.

7. Before you lower the bucket, make sure that the hauling unit is not under the bucket.

8. Lower the bucket while you position the loader for the next load.

Loading with a Bucket from a Bank

WARNING: Personal injury or death can result from falling material. Remove any overhang and watch for sliding material.

1. Start at the base of the bank in order to load the bucket and follow the face upward.

2. Raise the bucket slightly and move away from the bank.

Multipurpose Bucket Operation

Loading with a Bucket

Open the bowl and position the bucket over the material that will be loaded. Lower the bucket and close the bowl.

The multipurpose bucket can be used when increased dump height is desired or when you are unloading sticky material. Position the bucket over the dump area and open the bowl.

Dozing

To use the bucket for dozing, open the bowl. Maintain a level cut.

Scraping

To use the bucket for scraping, raise the bowl slightly and position the bucket as if the bucket is used for dozing. When the bucket is loaded, tilt back the bucket and close the bowl. The bucket is dumped in the normal tilt forward position.

Pallet Forks

1. Slowly, move the machine into position and engage the load. The machine should be square with the load. Space the forks as far as possible from each other.

2. Move the machine forward until the load touches the carriage.

3. Push the kickout control to the OFF position in order to disable the lever detents. This will prevent the lever from being pulled into the DETENT position when you are handling delicate loads.

4. Lift the load carefully.

5. Operate the machine in reverse until the load is clear enough to lower.

6. Lower the load to the travel position.

Travel with the load as low as possible while you still maintain ground clearance. Travel with the load uphill on upgrades and on downgrades. For better visibility, travel in reverse with bulky loads.

Logging Fork Clamp

1. Open the top clamp. Position the fork in the center of the load.

2. Close the top clamp. Tilt the forks backward in order to hold the load against the uprights on the forks.

3. For the best operator vision and stability for the loader, carry the load as low as possible to the ground.

Position the load over the loading area. Tilt the fork downward and raise the clamp in order to release the load.

Material Handling Arm

Remove the retainer pins from the arm in order to extend the arm or retract the arm. To lock the arm into position, replace the retainer pins after the arm has been extended or retracted. Push the kickout control to the OFF position in order to disable the lever detents. This will prevent the lever from being pulled into the DETENT position when you are handling delicate loads. Lift the load close to the machine for best stability. Move the machine slowly in order to avoid excessive load swing. Do not apply side loads on the hook and on the shackle. Check the condition of the hook, of the shackle, and of any lifting chains. Replace any worn parts.

An Electric Hybrid Bulldozer Goes On Sale

December 29, 2009 | 13 Comments

With a little fanfare Caterpillar announced last week they’re shipping a diesel engine driven generation set to electric motor hybrid drive bulldozer.   The D7E model is in the upper midsize range with the Cat C9.3 ACERT(TM) diesel engine rated at 235 net horsepower (175 kW) driving a powerful electrical generator that produces AC (alternating current).  Then the current flows through special armored cables and military-grade connectors to a solid-state inverter, that forwards the AC current to the propulsion module. It’s a series type hybrid that has clues for everyone else.

Caterpillar D7E Generator. Click image for a larger view.

Within the propulsion module are two heavy-duty electric motors using the AC current that drives through common gearing into the differential steering system. Power from the steering system is transferred via axles to the mechanical, double-reduction final drives to provide smooth, infinitely variable driving force to the tracks.

Caterpillar D7E Power Train. Click image for a larger view.

Noteworthy is that this system does not use hydraulic pumps and motors for power transitions.  Hydraulic hybrids are much more common than regular folks realize from self-propelled and riding lawn mowers, Bobcat loaders on to large farm machinery and some models of those giant mining trucks.

What Caterpillar has done is engineer the pattern set out in diesel locomotives where a diesel engine to hooked to a generator powers electric motors for the drive wheels.  The cream is in the efficiency numbers.

Caterpillar D7E Graphic Features. Click image for the largest view.

Caterpillar is claiming, and the numbers will likely be borne out by buyers is 10% to 30% lower fuel use per hour that would move at least 10% more material per hour as the blade size is larger than the engine with transmission model.  That should take overall efficiency to an average or better than 25% more work for unit of fuel.  Across the whole of the earth moving industry that would add up to a significant amount of diesel fuel.

Another benefit is the near elimination of dragging one side to steer.  Cat’s brochure claims 50% better steering performance, which in tighter working quarters where there is a lot of directional change has to be better than the 50% number.

For up time situations where dozers see a lot of continuous use, Cat points out that the electric drive model has 60% fewer moving parts.  They expect up 50% longer life from the propulsion unit and the lower track and suspension units should come in lasting 35% to 70% longer.  One could think electric drive is gentler on the tracks and suspension.

Caterplllar D7E Electric Power Train Graphic. Click image for the largest view.

Electric drive brings serious improvements to operational and life expectancy costs.  Add to that there are some things such as the transmission that need lots of lubricating oil, filters and attention, which are simply missing, saving a lot of maintenance costs.  The power train maintenance remaining has doubled time periods before attention in needed.

Cat began its effort to engineer electric hybrids drive back in the 1990s.  At brochure writing there were 18 dozers running at customer’s sites following 50,000 hours of laboratory development and test site work, so far.

The engine runs in a narrow rpm range between 1,500 and 1,800 rpm, instead of between 1,600 rpm and 2,200 rpm in the conventional D7R Series 2. Because it drives a generator instead of a powershift transmission, the D7E’s engine doesn’t need to rev as high or low to regulate speed.  The D7E produces slightly lower power than the Cat 3176 engine in the conventional D7R—however, increased drive train efficiency allows the D7E to deliver better performance from less horsepower, resulting in improved productivity and lower fuel consumption.

Current flows from the generator through special armored cables and military-grade connectors to a solid-state inverter, then to the propulsion module. Within the propulsion module are two heavy-duty electric motors that drive through common gearing into the differential steering system.

Caterpillar D7E Power Flow Block Diagram. Click image for a larger view.

Advanced electronics provide DC (direct) current to power the accessory system. The modular heating and air conditions system, water pump and battery charger are electrically powered for maximum reliability in varied conditions.  The engine has no accessory drive belts, everything is direct or electric drive.

Customer testers are saying things like, “It feels like it has the power of a D8, Never stops. Great looking dozer. Great visibility to the work area.”  The D7E sports a very spacious and comfortable cab.  Setup with a guidance system, it’s a very good finishing machine.

The customers like all the adjustable settings on the controls and arm rests, and like not shifting gears and letting the dozer do the work.  The lighting is “awesome” on this dozer when equipped with a 10 light group package.

The machine is extremely quiet and starts great in cold temperatures. The dozer and steering controls are very responsive. Track speed control is really good when going over a crest and there’s good side-to-side stability.  The electrically controlled hydraulic system is very fast and responsive.  Customers are consistently confirming the 10-30% fuel economy advantage.  In some applications, greater economy benefits are reported.  Just what those applications are is of considerable interest.

Pricing for an initial purchase for a new D7E with electric drive will be approximately 12% less than a larger class D8 and about 20% more than the conventional D7R. That would make the buying minus operating costs savings balance in a 2 ½ year payback compared to a conventional machine.  Cat would do well to try a little harder to drive down the purchase price.

The Cat Dealers are now taking orders for production that began in October 2009.The dozer is in limited production during the ramp up, with full production capacity due in early 2010.  The conventional D7R Series II will remain available until mid 2010 suggesting that the conventional design is on its way out if the press release writer got the matter correct.

The stepping down from diesel locomotives to huge mining trucks and now the popular midsize bulldozer shows all consumers that the series hybrid can pay off handsomely

for fuel and operating costs.  Here Caterpillar is showing with increasing accuracy the benefits that the series hybrid offers in performance and operating costs. Caterpillar dozers while common are by no means the kind of unit volume a popular automobile model would propose.  One should expect that a series hybrid auto could be less costly to buy than the same car with a larger motor, transmission and all the needed support equipment. Price parity should include some battery or capacitor storage and still get price parity.

Cat is also making clear that the next step can have a major impact on oil use, running expense and product lifetime.  Its been known for decades in the railroad business and now in earth moving that series hybrids are very efficient, now its tricking to smaller machines.  Series hybrid light trucks and automobiles should come soon, saving those buyers a lot of fuel and maintenance costs with better performance.

I can assure you of one thing, if this weren’t worthwhile, Caterpillar would not be offering such a machine.  Series hybrid works.