Hydra ulic Ho

ok-Up (C

BH 80) Fo

r

exceed 2800 PSI.

 

 

 

 

Tractors With Closed- Center Hydraulic

3. A closed-center plug in the b ackhoe control valve

Systems (Figure 21)

drauli c sy stems,

to make it a n on-circulating or a demand

type s ys-

There are two basic types of hy

tem.

 

 

 

 

open -center and

closed-cente r. The ope n-center

4. A low pressure surge valve in the return line to

system constantly pumps oil thr

ough the hydraulic

keep the tractor back pressure surges from dam-

cylinder operating val ves and returns the oil to the

aging the ba ckhoe control valve seals or tractor

reservoir. The closed-cent er system does not pump

system. A surplus flow line from t he relief valve car-

oil until there is a dem

and f or o il from one of the

ries o nly the excess sur ge oil direct ly back to t he

hydraulic cylinders.

 

 

 

tractor hydraulic r eservoi r so that it

bypasses all

In this case, CL OSED-CENTER m eans that when

other functions.

 

 

 

 

cylinders are in the neutral position, there is no flow

Backhoe Operation

 

 

 

the operating v alves which control the hydraulic

 

 

 

 

 

of oil through the valves. As long a s the engine and

Fot the most p art, a ba ckhoe will function about the

pump are ru nning, a co nstant stan d-by oi l of p res-

sure approx imately 2000 PSI or mo re is maintained

same whether it is powered by an

ope n-center o r

in the system. Press ure oil is av ailable instantly to

closed-center hydra ulic sys tem. Howev er there are

go to work when any one of the ope rating valves is

some diffe rences which t he operator s

hould be

opened.

 

 

 

 

aware of when utiliz

ing a closed-Ce

nter h ydraulic

Because there must be no flow through the backhoe

system.

 

 

 

 

As a backhoe function (lifting, actuating the bucket to

control valve when the levers are in neutral position,

the backhoe must be

converted fo r closed-center

fill it, e tc.) becomes increasingly di

fficult a nd the

operation.

 

 

 

 

hydraulic system pressure is rising closer to its maxi-

 

 

 

 

mum setting, ther e wil l be a noticeab

le slow do wn

Hook-Up Requirements

 

 

before stopp age occurs. As the system pressure is

 

 

approaching maximum, the pump is also

beginning

The hook-up of the CBH 80 Backhoe to the closed-

to str oke back for less and less fluid

delivery. At

maxi mum p re ssure, th e pu mp is completely

center system requires more th an conn ecting it to

destroyed and there is no delivery.

 

 

 

the remote couplers. The required devices are:

 

Therefore, when working various backhoe functions

1. A flow r estrictor in the pressur e li ne to keep

the

at or near maximum ability, a closed center system

speed of the backh oe operatio n within s afe and

will g ive t he o perator th e impression that the bac k-

acceptable limits.

 

 

 

 

hoe is sluggish a

nd somewha

t unresponsive.

2. The main relief valve in the backhoe control valve

Learning to e ase up slight at t he first i ndication of

slow down will permit the backhoe to perform at con-

must be replaced with plug, to allo w tractor system

tinuing maximum speed and efficiency.

 

relief to control pressure. System pressure must not

 

Figure 21

 

 

To Tractor

 

Surge Relief

 

 

 

 

 

 

Reservoir

 

Valve

 

 

 

 

Replace Main Relief with

 

 

 

 

 

 

 

 

Closed-Center Plug.

 

 

 

 

 

 

 

 

 

 

 

 

Couplers

 

 

 

 

 

 

Hoses Supplied

 

 

 

 

Replace Open-Center Plug

 

 

by Customer

 

 

 

 

 

 

 

 

 

 

 

with Closed-Center Plug,

 

 

 

 

 

 

 

Shown.

 

 

 

 

 

 

 

 

41

Page 42 Page 44
Page 43
Image 43
Bush Hog CBH60 Hydra ulic Ho Ok-Up C BH 80 Fo, Tractors With Closed- Center Hydraulic, Systems Figure, Backhoe Operation
Page 42 Page 44

CBH60, CBH70, CBH80 specifications

The Bush Hog CBH Series is a prominent lineup of compact, high-performance hydraulic blade mowers ideal for maintaining fields, pastures, and overgrown areas. Comprising models CBH80, CBH70, and CBH60, this series is specifically designed for efficiency and durability, making it suitable for various applications, from agricultural uses to residential properties.

One of the standout features of the CBH Series is its robust construction. Each model is built with a heavy-duty frame designed to withstand the rigors of demanding tasks. The decks are made from high-quality steel, offering enhanced durability while maintaining a lightweight design to optimize performance. With reinforced edges and an innovative design, these mowers guarantee longevity and resistance to wear in challenging environments.

The CBH Series integrates advanced hydraulic systems that ensure smooth operation and maneuverability. The hydraulic drive provides excellent power transmission, allowing users to tackle even the most stubborn vegetation with ease. Each model features adjustable cutting height settings, which give users the flexibility to achieve the desired finish. This adaptability is essential for different terrains and types of foliage.

Another key characteristic of the CBH models is their user-friendly design. The intuitive controls allow for easy operation, making it accessible even for those who may not have extensive experience with machinery. The cutting decks feature a quick-release mechanism, streamlining maintenance and facilitating blade changes when necessary.

The CBH80, CBH70, and CBH60 differ mainly in their width and cutting capabilities. The CBH80 boasts an impressive cutting width of 80 inches, making it ideal for large open fields, while the CBH70 offers a 70-inch cutting width, perfectly balancing efficiency and maneuverability. The CBH60, with a width of 60 inches, is designed for tighter spaces, allowing for easy navigation around trees, fences, and other obstacles.

Safety is paramount in the design of the CBH Series. Each model incorporates features such as safety guards and shields to protect users from debris during operation. Furthermore, the mowers are equipped with a quick-stop system that halts blade rotation almost instantly when the operator releases control, enhancing overall safety.

In conclusion, the Bush Hog CBH Series, with its models CBH80, CBH70, and CBH60, embodies a harmonious blend of power, durability, and user-centric design. Equipped with innovative technologies and safety features, these mowers are well-suited for various operational needs, proving to be invaluable tools for anyone looking to maintain their land effectively. Whether you have extensive acres to manage or a smaller yard, the CBH Series offers the versatility and performance to meet your mowing requirements.
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