Vacuum seed meter


Vacuum seed meter

Pro-Series™ vacuum seed meter

The vacuum meter system gently pulls and holds individual seeds to the holes of the seed disk for population control and spacing accuracy, equaling better crop stands and profit. Vacuum seed meters can plant a wide variety of crops and seed types by simply changing seed disks and adjusting vacuum level. Vacuum seed meters are available for planters with MaxEmerge™ XP or Pro-Series XP™ row units.

Additional features of the vacuum seed meter include:

One moving component (the seed metering disk) for minimum maintenance requirements
Meter located at each row unit for accurate seed delivery
Good hopper seed flow characteristics for longer operating time per hopper fill
Adjustable baffle (MaxEmerge only) to control seed flow into the seed meter reservoir, maintaining proper meter fill for the type of seed being planted
Low airflow in meter so seed treatments are not removed

Vacuum meter hub and latching handle

Pro-Series vacuum meter with disk

Both the Pro-Series and MaxEmerge vacuum meters are equipped with a heavy-duty hub spring and disk latching handle. The spring ensures the seed disk stays properly positioned when operating flat style seed disks and higher vacuum levels. Proper seed disk positioning means repeatable seed singulation, time after time. The disk latching handle is designed easy operation and effortless seed disk changeover. The hub is also machined to tight tolerances to further ensure alignment of metering components.

Operating characteristics of vacuum seed meter

Operating speed

The vacuum seed meter is capable of operating at faster planting speeds than mechanical meters (up to 8 mph). However, planting accuracy will be influenced by seedbed conditions and the operating characteristics of the seed meter. Rough seedbeds and fast planting speeds (above 5.5 mph) typically deteriorate seed placement accuracies.

The chart illustrates the effect operating speed has on population when using the vacuum meter. The operating band (color area) illustrates how the vacuum meter performs in relation to the desired population (indicated by horizontal line). The width of the band is due to various sizes and shapes of seeds and planting rate variations.

When operating on slopes above 15 degrees, increased or decreased population may result. To minimize this effect, reduce speed and consider using a flat style seed disk with increased vacuum level.

Vacuum meter seed disks

Flat-type and cell seed disks shown

Seed disks are made of a durable plastic composition. The unique cell disk design allows planting a variety of seed sizes without any additional parts or individual meter adjustments. Another advantage of cell type seed disks is the lower vacuum requirement compared to flat style seed disks. Lower vacuum levels mean less hydraulic demand from the tractor.

Both the MaxEmerge and Pro-Series vacuum seed meters can also utilize flat-style seed disks. These disks are recommended in crops where seed is typically difficult to singulate due to inconsistent seed size or shapes, or on slopes where achieving target populations can be difficult. Flat seed disks do not have a cell to help carry the seed, and thus require higher levels of vacuum to meter seed. Flat-style seed disks do require additional meter components to operate.

A double eliminator and knockout wheel assembly is needed to singulate seeds when using a flat seed disk. While function is the same, different double eliminator assemblies are available for the MaxEmerge or Pro-Series meters. The knockout wheel is common between both meter styles and ensures seed is cleared from the seed disk hole. The knockout wheel is installed in place of the wiper used with celled disks.

Flat and celled type seed metering disks are available to allow planting a wide variety of seed types.

Corn (field, popcorn or sweet corn)
Soybeans
Cotton
Sorghum
Sugar beets
Sunflowers
Edible beans/peas
Peanuts
Melons, squash, cucumbers

Pro-Series XP row units, which are used only with the Central Commodity System (CCS™) are compatible only with crops that the Central Commodity System is approved to plant.

Corn
Popcorn
Sweet Corn
Soybeans
Sunflowers
Sorghum
Cotton

NOTE: Due to small seed size and low planting populations, sugar beets can be planted with Pro-Series style meters by adding hopper extensions and not using the CCS tank. These hopper extensions can also be used for planting test plots.

IMPORTANT: Proper seed disk selection is essential for optimum seed meter performance.

Vacuum blower assembly

Vacuum blower shown on 1790

Vacuum is created by a hydraulically driven vacuum blower assembly mounted on the planter frame. The vacuum blower requires a tractor with a closed-center hydraulic system and a separate selective control valve (SCV). For tractors with open-center hydraulic system, a vacuum 540 or 1000 rpm PTO driven hydraulic pump system is available. PTO pumps offered from the factory are limited to 15 row applications or less. For applications of 16 rows or more, consult DTAC.

Vacuum blower assembly capabilities and reliability continue to improve with time. The increased reliability of today's vacuum blowers (since 2006) can be attributed to a larger displacement case drain motor (3.5 cc vs. 2.2 cc) driving a larger diameter blower fan (18-5/8 in. vs. 17 3/8-in.) that runs at a slower speed, providing the same amount of vacuum pressure at the seed meter. Another advantage of the larger-diameter fan and larger-displacement case drain pump is that it eliminates the need for a second vacuum blower assembly on a 12-row planter when using a flat seed disk. Current vacuum motors are capable of providing vacuum for 12 row units running flat disks, or 16 row units running celled disks.

Different vacuum levels are required depending on the crop to be planted. A hydraulic control valve lets the operator regulate vacuum blower speed, thus changing the vacuum level. On late model John Deere tractors, vacuum levels are set from the tractor seat using the SCV TouchSet^TM controls. The control valve is not needed. At full flow, the system flows up to 5 gpm per motor. Only very large seed or flat seed disks require this much flow.

Convenient vacuum gauges located on the planter hitch give a visual indication of the vacuum level. When using a SeedStar™ monitor, the vacuum level can be displayed on the monitor. Consult the vacuum metering seed charts in the operator's manual for initial vacuum setting recommendations.

Vacuum meter case drain

Case drain coupler 7000 Series Tractor

All planters with vacuum metering systems have case drain motors on the vacuum blowers. As of May 2004, all case drain lines will have a flush-face case drain coupler on the planter and will require a corresponding flush-face case drain coupler on the tractor. The flush-face coupler simplifies implement attachment by allowing operators to easily identify the case drain. The unique hose tip is unable to hook into another coupler on the tractor, ensuring the correct setup.

It is important to hook up this case drain hose to prevent the continuous and complete draining of hydraulic fluid due to the relief feature that opens the coupler when the pressure reaches 10 psi. This relief feature is designed to protect the motor shaft seal if for any reason the case drain hose was not connected to the tractor. The flush-face hose tips have less back pressure than ISO case drain tips and the flat surface makes these couplers easy to clean, providing less chance for contamination.

The case drain line is also used with all CCS fan motors.

Last Updated : 25-Oct-2009