ICVD – Walterscheid Powertrain Group

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ICVD®

Integrated Continuously Variable Drive

www.icvd.walterscheid.com

CLEAR DEMANDS!

For certain applications, self-propelled agricultural and construction machin-
ery, such as wheeled and telescopic loaders, forestry machines, combine
harvesters and also choppers, not only need to generate high tractive forces,
but also have to be capable of covering long distances at the highest possible
speed.

Up to now, both of these functions have been realised by hydrostatic drives with manual
gearboxes. This concept has proven to be less than optimum in practice, since the machine
usually has to be at a standstill to switch between gears, making the procedure both incon-
venient and time-consuming.

Continuous variability is what is called for here in practice – with a variable drive concept and
substantially greater operating convenience for the driver.

OUR SOLUTION!

Walterscheid developing a continuously variable, hydrostatic travel drive for
self-propelled agricultural and construction machinery. The ICVD® (Integrated
Continuously Variable Drive) makes it possible to drive through the entire speed
range without interrupting the tractive force.

The ICVD® is thus a symbiosis of time-proven drive concepts, combining their advantages, but
without having to accept the drawbacks of the old solutions.

The ICVD® is the only continuously variable, hydrostatic travel drive to use 45° large-angle tech-
nology and comprises a gearbox, a hydraulic motor and a control unit.

2

CONTENT

Characteristics

Technical Data

Hydraulic Control

ICVD® GT-S1 N 233V

ICVD® GT-S1 A 233V

ICVD® GT-S1 A 233V-K

ICVD® GT-S1 N 370V

ICVD® GT-S1 N 370V-K

Safety

Data Sheet

4

5 – 6

7

8 – 9

10 – 11

12 – 13

14 – 15

16 – 17

18

19

3

Continuously Variable Hydrostatic Drive with 45° Large-Angle Technology

Type: Variable-displacement axial piston motor

of bent-axis design for hydrostatic drives with

open or closed circuit.

The ICVD® is a continuously variable,hydrostatic
travel drive, comprising mechanical gearbox,

hydraulic motor and control unit.

BENEFITS

Continuously variable
hydrostatic travel drive

Optimised efficiency due to
integrated hydrostatic motor
with large-angle technology

Wider conversion range
with large-angle technology

Low noise

Reduced fuel consumption

Reduced tyre wear

4

TECHNICAL DATA
HYDRAULIC FLUIDS

The operating data and ratings are based on operation with
hy draulic fluids containing oxidation, rust and foam inhibitors.
These fluids must display good thermal and hydrolytic stability
in order to prevent wear, erosion and corrosion of the internal
components. The ICVD® can also be operated using fire-resist-
ant hydraulic fluids, but under modified conditions. Hydraulic
fluids may not be mixed. Contact Walterscheid service for fur-
ther information.

Suitable hydraulic fluids
> Hydraulic fluids to DIN 51 524, Part 2 (HM)
> Hydraulic fluids to DIN 51 524, Part 3 (HV)
> API CD, CE and CF engine oils to SAE J183
> M2C33F or G automatic transmission fluids (ATF)
> Multi-purpose agricultural oils (STOU)

Temperature
The temperature and viscosity requirements must be met.
The temperature should be within the limits indicated below.
The minimum temperature does not affect the motor compo-
nents, but may have a negative impact on power transmission.
The maximum temperature is dependent on the properties
of the motor material. It must not be exceeded and is usually
measured at the leakage-oil outlet.

Temperature range 1)
t min. = –20 °C Briefly, when starting cold
t max. = 115 °C Briefly

1) Measured at the hottest point, e.g. leakage-oil port

Viscosity
The viscosity should be within the recommended range (see
below) to achieve high efficiency and a long bearing service life.
The minimum viscosity may only occur briefly at the maximum
ambient temperature. The maximum viscosity may only occur
under cold-starting conditions, i.e. at appropriately limited rpm
speeds until the system has warmed up.

= 7 mm2/s

Viscosity range
Minimum
Recommended = 12-80 mm2/s Recommended operating

Maximum

viscosity
= 1,600 mm2/s Briefly, when starting cold

Briefly

FILTERING

To prevent premature wear, it is essential that the hydrostat-
ic drive system be charged and operated with clean hydraulic
fluid only. The hydraulic fluid is considered to be a component
of the overall machine. The filter system to be used must guar-
antee cleanliness class 20/17/12 or better to ISO 4406 under
normal operating conditions.

The choice of filter is dependent on various factors, including
the amount of dirt penetrating the system, the formation of dirt
particles in the system, the necessary cleanliness of the fluid
and the desired maintenance interval.

The filters must be selected in such a way that the above-men-
tioned requirements are met, efficiency and performance being
the underlying criteria. The respective demands on filtering in
different systems must be determined by means of trials. The
prerequisites for a definitive decision on the filter system are
monitoring of the prototypes, and assessment of the compo-
nents and performance, throughout the entire test period.

CAUTION!
INDEPENDENT BRAKE SYSTEM

Loss of the power connection in the driveline of a hydrostatic
system during an acceleration or braking phase, or in the neu-
tral position of the drive system, can lead to a loss of hydrostat-
ic braking capacity. For this reason, a redundant brake system
that is independent of the hydrostatic brake system must be
installed. The redundant system must be in a position to brake
the moving vehicle and/or to serve as a holding brake.

GEAR OIL

The ICVD® units are filled with gear oil before shipping. Any reg-
ular gear oil can be used that meets the following specifications:

Gear oil grade:
Performance Category: API-GL-5
Specification:

MIL-L-2105

SAE 90 EP oder 85W-90EP

The gear oil can be mixed with any other high-quality mineral
oil complying with the above API Performance Category and
MIL Specification.

Quantity:
The quantity of gear oil is approx. 4 l, although this varies, de-
pending on the selected installation position and transmission
ratio. Kindly refer to the customer drawing for the oil quantity.

Oil change:
First oil change: 500 hours of operation after putting the vehicle
into service. All other oil changes: after every 1,500 hours of
operation, but not less than once per year.

Oil disposal:
Gear oils based on mineral oil are not hazardous substances
within the meaning of the German Ordinance on Hazardous
Working Substances. They can be disposed of as waste oil and
recycled.

5

Continuously Variable Hydrostatic Drive with 45° Large-Angle Technology

TECHNICAL DATA
HYDRAULIC FLUID RESERVOIR

The air contained in the hydraulic fluid is eliminated in the hy-
draulic fluid reservoir during the dwell time. Fluctuations in vol-
ume are also equalised. These can be caused by heating of the
hydraulic fluid (expansion), cooling of the hydraulic fluid (con-
traction), actuation of differential cylinders.

The hydraulic fluid reservoir must be capable of equalising the
volumetric flow fluctuations under all operating conditions. The
minimum reservoir capacity in litres should be 5/8 of the max-
imum charging-pump volumetric flow in l/min. The minimum
fluid content to be provided is 1/2 of the charging-pump vol-
umetric flow in l/min. This results in a dwell time of the fluid in
the reservoir of 30 seconds, allowing the air contained in the

hydraulic fluid to rise to the surface of the fluid. If a reservoir is
designed according to these guide values, a sufficient equal-
ising volume is available for most systems/applications with
closed reservoir (e.g. without breather).

The suction port leading to the charging pump must be located
above the reservoir bottom in order to prevent the aspiration of
sediment. The return line port on the reservoir must be located
below the fluid surface and as far as possible away from the
suction port. Air elimination is improved by inclined, perforat-
ed interceptor plates, installed between the return and suction
ports.

} Variable-displacement axial piston motor of bent-axis design for a closed or open circuit
} Without control pressure (initial position), the power unit is at the maximum pivoting angle (closed circuit)

Geometric displacement volume 233

Geometric displacement volume 370

POWER UNIT

Type

Sense of rotation

} Clockwise and counterclockwise

} Max. 233 cm3/rev.
} Min. 40 cm3/rev.
} Optionally 0 cm3/rev.

Continuous speed

} At max. pivoting angle: 1,720 rpm
} At min. pivoting angle: 3,860 rpm (°7)

Maximum speed (briefly):

} At max. pivoting angle: 2,200 rpm
} At min. pivoting angle: 5,125 rpm (°7)

Pivoting angle

} Max. 45°, min. 7°, optionally 0°
} Theoretical specific torque: 3.7 Nm/bar

HYDRAULIC PARAMETERS

} Max. 370 cm3/rev.
} Min. 64 cm3/rev. (°7)
} Optionally 0 cm3/rev.

Continuous speed

} At max. pivoting angle: 1,490 rpm
} At min. pivoting angle: 3,295 rpm (°7)

Maximum speed (briefly):

} At max. pivoting angle: 1,820 rpm
} At min. pivoting angle: 4,330 rpm (°7)

Pivoting angle

} Max. 45°, min. 7°, optionally 0°
} Theoretical specific torque: 5.9 Nm/bar

Operating pressure

} Working pressure: max. p 480 bar
} Max. pressure, briefly: p 510 bar

Filtering

} Required cleanliness class to ISO 4406:

20/17/12 or better

Housing pressure

} Max. continuous pressure: 2 bar; briefly 5 bar

6

ICVD® CONTROL

ICVD® 233

2

1

6

5

3

4

ICVD® 370

1. Proportional control

(electric or hydraulic version)

2. Stroke adjustment of the swivel bracket
3. Pressure limiting valve, purging (optional)
4. Directional valve, purging (optional)
5. Pilot valve for control pressure switching

(optional)

6. PCOR (optional)

7

Continuously Variable Hydrostatic Drive with 45° Large-Angle Technology

ICVD® GT-S1 N 233V

Transmission ratio i

0.94 – 1.6

Torque at the output shaft Md

1,280 – 2,560 Nm

Max. drive shaft operating angle 1)

< 3° and Z-bend Drive shaft flange DIN ISO 7646 120 x 8 x 10 Max. operating pressure 480 bar Installation position Vertical 1) Mass (without fluids) m Approx. 140 kg Transmission oil quantity Approx. 4 l Transmission oil grade SAE 90 API-GL-5 Hydraulic fluid quantity Approx. 15 l 1) Other versions on request A B DIRECTION OF FLOW Sense of rotation Clockwise (CW) Port A Outlet Counterclockwise (CCW) Inlet Port B Inlet Outlet Definition of the sense of rotation: looking at the high-pressure ports on the control unit cover. MAINTENANCE AND OIL CHANGE Oil check after 500 hours of operation Oil change after 1,500 hours of operation or once per year 8 Kinematic diagram