John Deere Infinitely Variable Transmission (IVT™)
The revolutionary IVT provides excellent performance in all farming conditions.
 
Infinitely Variable Transmission

Infinitely Variable Transmission

The John Deere IVT is an easy-to-use transmission with simple and intuitive controls allowing you to move smoothly from 0.03 mph (50 meters/hr) to 26 mph (40 km/hr) and any speed in between. Never again is a gear too fast or too slow, the IVT provides a seamless range of speeds with no gaps. No clutching is required to start or stop the tractor. The footbrake with integrated AutoClutch performs like the brake in a car; simply depress both brakes and the transmission ratios down to a stop from any ground speed. To keep your 7020 Series Large-Frame Tractor stationary even on inclines, use the John Deere exclusive PowerZero™ feature.  The John Deere IVT is available on the 7720 and 7820 tractors and standard on the 7920 tractor.

The IVT has a fully integrated Electronic Management System that allows the engine to communicate 100 times a second with the transmission.  This technology allows unrivalled ease of operation among all transmissions making it ideal for agricultural businesses with flexible labor schemes.  Electronic communication and interaction between the engine and the transmission allows optimum productivity and efficiency at any engine speed.  This is achieved because the operating conditions are being constantly monitored and relayed to the Electronic Management System, which then automatically determines whether the tractor is in a loaded condition or a light- to no-load condition and makes the appropriate adjustments.
 
The Electronic Management System works with the IVT transmission and engine to maintain the selected travel speed at reduced engine rpm when the IVT selector activates the system resulting in increased efficiency and reduced fuel consumption.

IVT Selector
 
IVT selector switch

IVT selector switch

The IVT selector has four positive detent positions:

  • Position 0, ''Off''
  • Position 1, "Automatic mode" 
  • Position 2, "Automatic mode" 
  • Position 3, "Automatic mode" 
 
''Off'' Position - Used for some special applications: When turned off, the Electronic Management System is disabled and the transmission operates as any traditional transmission where the operator sets the engine speed and ground speed.   The transmission will not automatically shift with varying engine load to maintain your selected ground speed.  For most applications, positions 1, 2, or 3 should be selected to provide maximum productivity and minimize fuel consumption.

Position 1 - Primarily for PTO-powered applications: In positions 1, 2, or 3, the tractor tries to maintain the selected travel speed at reduced engine rpm for reduced fuel consumption and increased efficiency.  In position 1 and the PTO engaged, the engine rpm can only be reduced minimally in order to maintain proper PTO operating speed of 540 or 1000 rpm.  When a load is placed on the tractor, the engine will first increase power to maintain PTO rpm.  Once maximum engine power is reached and additional load is placed on the tractor, the IVT transmission will reduce speed enough to keep the motor at maximum power until the tough condition is over, then the transmission will increase the speed back up to the speed selected.  Once the load is reduced further, engine rpm will again drop to reduce fuel consumption.  All of this is done automatically through the Electronic Management System maintaining communication between the engine and transmission.

Position 2 - For heavy draft and tillage applications or when hydraulic flow is needed: As in position 1, the tractor will try to maintain the selected ground speed at reduced engine rpm for improved efficiency and reduced fuel consumption.  The minimum engine rpm is adjustable in the CommandCenter™ to customize the tractor to the application.  Since the PTO is no longer involved, the rpm is allowed to go lower than in position 1.  As before, when  the load increases on the tractor, the engine increases power until maximum power is reached, then, if needed, the IVT transmission will ratio down (slow the tractor) enough to keep engine power at maximum.  Once the tractor is through this tough spot, the IVT will ratio up (increase speed) back to the selected speed and the engine will reduce rpm.  All of these operations are performed automatically by the Electronic Management System.

Position 3 - For transport and light tillage applications: In this position, the engine rpm will reduce lower than in positions 1 or 2 to save additional fuel.  The tractor is capable of full transport speed of 26 mph (42 km/hr) at very low engine rpm's (as low as 1200).  As before, the minimum engine rpm is adjustable in the CommandCenter to allow the operator to customize the tractor to the applications. 

In the end, the Electronic Management System operates similar to the traditional "gear up and throttle back" operation performed manually.  However, because the Electronic Management System is continually communicating with the engine and transmission and making appropriate adjustments based on inputs received from the tractor, it responds quickly and precisely to changing conditions.  This allows maximum efficiency and productivity from the tractor.  Because the changes are automatic, it reduces the reliance on operator experience to make the appropriate manual adjustments.  Even the most experienced operator will see enhancements to tractor productivity while minimizing fuel consumption in all applications.    

IVT controls
 
The IVT features four main controls to operate the transmission:
  • Speed control lever with two variable speed bands.
  • Set speed adjuster used to set the maximum speeds in each of the variable speed bands. Setting of maximum speeds can be adjusted either on-the-go or when the tractor is stationary.
  • Multi-function left-hand reverser with six positions.
  • Foot brake, with integrated AutoClutch function.
Speed control lever

Speed control lever

Speed control lever
The speed control lever controls the commanded speed of the tractor. This speed is variable from a very slow speed at the bottom end of the first band up to the preset set speed 1 at the end of the first speed band. The commanded speed is then variable from set speed 1 to set speed 2 at the end of the second variable speed band.
 
As the operator moves the lever within or between speed bands, the Electronic Management System ensures smooth, quick, and powerful acceleration or deceleration, regardless of load or ground speed.
 
The cornerpost displays ground speed (calculated from tire size and axle rotational speed, or radar speed if equipped), commanded speed (determined by the position of the speed lever), and engine speed.
Set speed adjusting wheel

Set speed adjusting wheel

Set speed adjusting wheel

The set speed adjusting wheel is a rotational wheel located on top of the speed control lever. The wheel is quickly and easily adjusted with the thumb. It is used to set the maximum speed for each speed band. The speed wheel rotates infinitely with no stop or start position to allow quick adjustment of the maximum set speeds.

Set speed can be adjusted on-the-go or while stationary. While in motion, the speed lever must be in the speedband for which you wish to set the maximum set speed. While stationary, all set speeds may be adjusted while the left-hand reverser is in the scroll position. The maximum speed selected is shown on the digital display.

Left-hand reverser

Left-hand reverser

Multi-function left-hand reverser
 
The IVT left-hand reverser is more than just a directional control; it is a six-position multi-function lever.
Park Position - Engages the electromechanical park lock. Lever must be in this position to start the tractor.
Neutral Position - Straight above the park position. Allows tractor to roll freely.
Scroll Position - Center Position without being held. When the reverser lever is placed in this position, the tractor will not roll. The tractor will be in PowerZero while the set speeds are set to the desired speeds. It is in this position that the four set speeds can be selected while the tractor is stationary. PowerZero™ Position - Center Position held towards the operator. Shifting the reverser lever to PowerZero position and holding it there will keep the tractor stationary regardless of load or incline. This is ideal for loader work of other operations where the tractor needs to be totally stationary for a short period of time.
Forward and Reverse Positions - Traditional left-hand positions. For changing direction of travel, these positions are easily shifted between smoothly and positively.
Foot brake with integrated AutoClutch

Foot brake with integrated AutoClutch

Foot brake with integrated AutoClutch function

The electrohydraulic controlled brakes on IVT equipped tractors have an integrated AutoClutch function.  At low idle only, the tractor will stop by depressing only one brake pedal.  Pressing both brakes simultaneously will stop the tractor from any ground or increased engine speed.  This can be done on flat ground or steep slopes simply by using the brake pedals, it is not necessary to depress the clutch.  It is recommended to lock the brake pedals together when operating on roads.
 
Note: The preferred method of stopping heavy towed loads is to slow the IVT speed lever and lower engine rpm first, and then depress both brake pedals.

 

Foot throttle

Foot throttle

Foot throttle

All transmissions are available with a factory installed foot throttle for ease of operation. Using the optional foot throttle in conjunction with the footbrake with integrated AutoClutch is the preferred method of operating an IVT equipped tractor on the road. Using the foot throttle to make minor adjustments to tractor speed simplifies operation of the tractor. When coming to a stop, let off the foot throttle, reducing both engine rpm and speed, then depress both brake pedals.  To resume movement, simply release the brakes and depress the foot throttle. 

Base Equipment On : 7920 tractors
Optional Equipment On : 7720, 7820 tractors
 
Last Updated : 05-Oct-2010