Paralleling Carriage Construction

Undercarriages

ASV’s track technology can be divided into three equally important categories: contact points, internal drive and suspension. Contact points (bogie wheels), are what transfers the vehicle weight through the track into the ground. By having more contact points, more area of the track is transferring vehicle weight, thereby providing much more traction. The internal drive is inside of an ASV track and has molded rubber drive lugs that mesh with an internal drive sprocket. Internal drive allows for many key features, including maximum speed, track integrity and less friction. Suspension offers many benefits, including more traction, longer track life and longer machine life due to less vibration. Most importantly, it makes for a much more comfortable and productive operator.

ASV’s flagship machine is the SR-80, and the significance of the SR-80 begins with the undercarriage. The ISR-4 is a completely new undercarriage that ASV engineers spent nearly two and a half years developing and testing. The SR-80 — like all ASV machines — was built from the ground up to run on a unique suspended rubber track undercarriage. Among the ISR-4 undercarriage’s many attributes are the widest rubber tracks in the industry (20 in.) and an independent, multi-level suspension, with four-wheel carriages on each side that flex independently to maximize ground contact over uneven terrain. A new open undercarriage prevents dirt buildup, helps to lower maintenance requirements and improves durability.

The ISR-4 undercarriage will flex in multiple directions, which means that it has the most track on the ground at any given time, even over difficult terrain. Tracks on the SR-80 are driven by two-speed drive motors, capable of travel speeds as high as 12.5 mph in the high speed range and as high as 7 mph in the low speed range, easily making it the fastest machine in its class.

Tracks

ASV’s proprietary rubber track is the culmination of more than 20 years of research and development. It’s a lightweight, pliable, yet tough composite material. No steel is used anywhere in the rubber track to avoid the problems of corrosion, delamination and early failure that are

common on rubber tracks with steel inserts. ASV does not offer different track width options on individual machines. Depending on the machine, track replacement can run anywhere from $1,400 to $3,000 each.

New Holland

Products

New Holland has been manufacturing compact track loaders for more than a year and a half. Most recently, New Holland introduced the C175 unit in January 2007. The company currently has three models — the C175, C185 and the C190 to cover ROCs of 2,200 through 2,900 lbs.
Its current production represents the first generation of New Holland compact track loaders.

Undercarriages

New Holland extracted proven technology found in its successful crawler-dozer family to develop the undercarriage for its compact track loaders, which it calls simple, robust and stable. The angled covers on New Holland’s track loader undercarriages are similar to the angled covers on its crawlers, giving them better mud shedding properties. In addition, these units have scrappers in the back and in front to help channel the mud away from the undercarriage. The result is less time spent on cleaning the undercarriage and more productive operating time.

The rollers’ and idlers’ shafts are oil lubricated and permanently sealed for a maintenance-free, worry-free feature. New Holland track loader undercarriages are difficult to detract. The company’s rubber belts are steel-belted for additional strength and minimum slack adjustment. Additionally, the undercarriage system has a middle roller guide that helps keep the belt in line.
This means less downtime for better productivity. The track gauge, which is measured from the track belt mid-point to mid-point, is just under 5.5 ft, which is the widest in the industry (for the C185 and C195 models, says New Holland). This wide stance coupled with the 5.5 ft of track on the ground provides outstanding stability and ground pressures as low as 4.1 lbs per sq in.

The undercarriage will also let you know when it is time to adjust the belt’s slack. Eventually, the belt will make contact with the top of the track cover (you can hear it). To adjust the track, simply raise the front end of the loader with the bucket; use a wrench to remove one bolt, slide the cover back and grab a grease gun and pump grease into the grease fitting.

Tracks

New Holland uses the Bridgestone brand of tracks size widths of 15.7 and 17.7 in. on its larger C185 and C190 models. The C175 model uses a 12.6-in. wide Bridgestone track. The optional track on the C185 and C190 is the 15.7-in. wide.

Bobcat

Products

Bobcat entered the compact track loader market in 1999 with its first dedicated track machine. It was the first compact track loader with a solid-mounted undercarriage manufactured in the United States. Bobcat introduced its latest version of its compact track loaders — the K-Series — in 2006 with several significant changes to the cooling system and the undercarriage.

Today, there are five Bobcat compact track loaders that weigh significantly more than skid-steer loaders of the same size, giving them higher pushing force and allowing large loads to be lifted (from the T180 through T300 models).

Undercarriages

The undercarriage of Bobcat compact track loaders is what makes them so successful in mud, sand or other loose material. The popular track machines are driven by two powerful direct-drive hydrostatic motors. This feature minimizes moving parts and eliminates axles and chains. The two motors include internal tapered roller bearings to help carry heavy load stresses.

Rollers and idlers are designed to ensure smooth track operation. Triple-flange austempered ductile iron rollers guide both sides of the track lugs to maximize contact between the rollers and tracks and to help minimize any de-tracking. The rollers are permanently lubricated and require no periodic maintenance. Customers will be pleased to know that the only daily maintenance required is to remove debris in the undercarriage to prevent packing.

Single flange idlers guide and support the track around the ends of the undercarriage. The idlers are more tolerant of debris than dual flange idlers so de-tracking is minimized. Front idlers absorb shock loads and are part of a simple system which helps maintain track tension.

Exclusive C-pattern rubber tracks have steel cables and imbeds to increase surface life. Internal steel cables similar to steel belted radial tires provide a strong base. Steel imbeds guide and support the center of the track when engaging the drive sprocket. A special rubber compound is molded around the cables and imbed to produce a strong, continuous rubber track, reducing fatigue and cracking.

Tracks

Each individual size rubber track is designed and manufactured specifically for the Bobcat compact track loader it is used on. Bobcat compact track loaders have the unique ability to accommodate different track widths. Customers can choose between narrow tracks and wide tracks, including: T140 has the 11.8 in. as standard (no optional available); T180 has the 12.6 in. as standard (15.8 in. optional); T190 has the 12.6 in. as standard (15.8 in. optional); T250 has the 17.7 in. as standard (12.6 in. optional); and the T300 has the 17.7 in. as standard (12.6 in. optional). On the larger T250 and T300, the wide tracks are standard because so many customers like the 17.7-in. size. Regarding track cost, a new set of tracks will cost approximately $3,300 to $4,400.

Caterpillar

Products

Caterpillar Inc. launched its multi-terrain loader product line in 2001. All models are produced in Sanford, N.C. The units include “small frame” multi-terrain loaders including the 247B and the 257B, as well as large frame models such as the 267B, 277B and 287B.

Undercarriages

The rubber track undercarriages on the 247B and 257B use a unique rubber track system that provides low ground pressure, stability, high traction, fast travel and suspension. Machine weight is transferred to the ground through 24-wheeled contact points for the 247/257B, distributing the weight evenly throughout the track. The large ground contact area helps maximize traction and minimize ground pressure. The elevated, internal positive track drive keeps drive components away from ground debris and the rugged, durable rubber track is lightweight and pliable, yet reinforced with high-tensile strength cords. Heavy-duty, torsion axles suspend each side of the undercarriage from the machine frame and are shock absorbing.

The rubber track undercarriage for the 267, 277 and 287B capitalize on a dual level suspension. The rubber track undercarriage transfers machine weight to the ground through 48 contact points on the 277B and 42 contact points on the 287B. The machine weight is distributed evenly throughout the track, while the large ground contact area helps maximize traction and minimize ground pressure. The 267/277B have a ground pressure of 3.1 psi and 287B a 3.8 psi. Each unit’s elevated positive track drive keeps drive components away from ground debris. And with multiple levels of suspension, through two torsion axles and six articulating wheel carriages per side, the 287B undercarriage offers
a single torsion axle per side for suspension.

Cat has an agreement with track loader pioneers ASV, which designs and manufactures the company’s undercarriages.

Tracks

Cat offers 15-in. tracks for the 247 and 257B and 18-in. tracks for the 267, 277 and 287B. Turf tracks are becoming popular with these machines that are operated in applications such as sod farms and golf courses.

John Deere Construction and Forestry

Products

In 1997, John Deere entered the compact construction equipment business with a focused business unit (Commercial Worksite Products), beginning with a four-model introduction of skid steers. Deere currently offers two 300 Series compact track loaders in the same division — the CT322 and CT332.

Undercarriages

From an undercarriage standpoint, Deere compact track loaders represent the next generation of the
company’s machines. These loaders deliver an ultra durable track system with all steel rollers, idlers and sprockets utilizing the same design technology as Deere’s dozers. A robust, four-planet planetary final drive delivers industry-leading pushing power and torque to the tracks, while at the same time evenly distributing any shock loads the compact track loader encounters. Deere’s motor bearing support is massive compared to competition (says the company), ensuring long life under the most strenuous conditions.

Deere stresses its track loaders are not just skid steers with tracks. Compared to skid steers, the tracked machines are more robust in every key area, with heavier, stronger more robust structures to handle the additional loads the machines will encounter (these include larger coolers (hydraulic and engine) due to the higher engine load factors and higher transmission pressures these machines generate).

The only maintenance on a Deere compact track loader undercarriage is for the customer to check track tension once every 50 hours or once per week, which takes only minutes to complete and a grease gun to adjust, if needed. Checking track tension on a Deere is as simple as checking tire pressure on a car. The Deere undercarriage has completely encased hoses with an open design and easy-clean undercarriage, featuring a track frame designed to shed debris during operation.

Tracks

Both the CT322 and CT332 employ Bridgestone rubber tracks that are enhanced to fit where the track contacts the sprocket drive. While the CT332 comes standard with wide floatation 17.7-in. tracks, there is a 12.7-in. narrow track option. The mid-size CT322 comes standard with 12.7-in. tracks.

Case Construction

Products

Case started manufacturing compact track loaders in 2005 with the introduction of the 445CT and 450CT models. Today, Case manufactures four models of compact track loaders, including the 420CT and 440CT models. These are all first generation Case compact track loaders.

Undercarriages

Case based the design of its compact track loaders’ undercarriages on its extensive experience with large excavators and crawler dozers. It is built in-house and has a rigid track frame with has no moving parts, which the company says makes it easy to maintain.

The angled track frame cover and material scrapers keep material and mud from building up in the undercarriage and interfering with track movement. This means that you’ll spend less time cleaning out your tracks at the end of the day.

The one-piece final drive gives the machine more gear-to-gear contact for increased component life. It also provides for a better transfer of power, making the machine more efficient and less costly to operate. The whole assembly is raised up, keeping it out of the material you are working in. Also, duo cone face seals are proven dozer technology that reduce maintenance costs and increase undercarriage life.

Triple flange rollers help prevent de-tracking on slopes by using dozer-style rollers with a large inner diameter flange positioned between the track tabs. Lifetime sealed and lubricated rollers and idlers reduce the amount of material and moisture getting into the rollers and idlers, providing greater reliability, lower maintenance costs and a longer lasting machine. Easy track adjustment
is another key feature. Simply adding grease to a zerk fitting adjusts the track tension through a hydraulic

tensioning cylinder.

Tracks

The 420CT uses 12.7-in. wide tracks as standard. The 440CT uses 15.7-in. wide tracks as standard.
The 445CT uses 17.7-in. wide tracks as standard and 15.7-in. tracks as optional. And the 450CT uses 17.7-in. wide tracks as standard and 15.7-in. tracks are optional. Replacement tracks are about $2,200 per side.

Komatsu

Products

The Komatsu models CK30 and CK35 are the first two compact track loader models designed and manufactured by Komatsu at its production facility in Newberry, S.C. The company began shipments to dealers in June 2006.

Undercarriages

The Komatsu compact track loader frame is of the same basic design as its skid steer loader, but has been modified and strengthened to accept the CTL undercarriage. Features unique to the Komatsu are the three flange front idler system, the common mount of the idler and number one roller, and the upper track support/guide system. These contribute to track retention and durability.

Komatsu is quick to point out the fixed displacement drive motors on the Komatsu compact track loader undercarriage that deliver power through the multi-stage planetary gear system to the drive sprockets on each track. As the sprocket turns, it meshes with the steel pins and track guides embedded in the continuous rubber track. As the track rotates, the guides are routed through the upper track support system, which keeps the track in line with the sprocket and the front idler.

The Komatsu track loader is equipped with a three flange front idler that guides the track over the front of the undercarriage and maintains contact with both track guides. The unique design enhances the ability of the Komatsu undercarriage to retain the track even when working on slopes. The front idler is mounted on a sub-frame in the undercarriage and is actuated by a hydraulic track tension adjust cylinder and large recoil spring allowing easy adjustment by simply pumping grease into the adjustment chamber.

On the same sub-frame is mounted the first of five load rollers. These rollers are evenly spaced with minimal gap and allow for even and consistent distribution of the machine weight for even and consistent ground pressure and increased durability. The slightly elevated rear idler is set in a heavy framework and is mounted rearward from the drive sprocket allowing for an angled rear departure area of the track which enhances tractive effort in reverse.

Tracks

Komatsu offers both 12- and 18-in. wide tracks, but is most often equipped with 18-in. tracks to provide the lowest ground pressure. The upper surface of the undercarriage is tapered to allow dirt to fall off during normal use and has no pockets or cavities to retain dirt or debris. The mounting of the five lower rollers is below the side frame allowing mud and debris to be expelled as the machine travels. Replacement tracks are available through the Komatsu dealer network for approximately $2.800 per side.

Keith Gribbins is managing editor of Compact Equipment.