Log splitters represent one of the most basic applications of fluid power and are probably the most popular project for fluid power do-it-yourselfers. The most basic version consists of a pump, directional valve, and cylinder to apply hydraulic pressure as brute force to a wedge, which is mounted at the end of the cylinder’s piston rod to split the log. Of course, a relief valve should always be provided for safe operation. But beyond a reservoir, fittings, and other bare essentials, the basic hydraulic system of a log splitter doesn’t consist of much else.
However, in their quest to build a better mouse trap, would-be inventors and legitimate manufacturers incorporate auxiliary features to make log splitting faster and more efficient. One of the most common tricks of the trade uses a two-stage pump — commonly referred to as a high-low pump. A high-low pump has two pumping chambers driven by a common shaft. One chamber has a large volume to produce relatively high flow but with low pressure capability. The smaller chamber produces much less flow, but accommodates much higher pressure.
Conventional work cycle
In a typical log splitter, the operator places a log on the splitter, then shifts a directional valve to route fluid from the pump to the cap end of the hydraulic cylinder. The combined flow from both pumps extends the cylinder’s piston rapidly to reduce the time it takes to advance the wedge to the engage the log. Once the wedge engages the log, the log resists further extension of the cylinder, so fluid pressure builds.
Once fluid pressure exceeds a predetermined threshhold, the large displacement pump disengages, and full motor torque is applied to the smaller-displacement pump. The smaller pump moves the piston rod at lower speed, but can achieve higher pressure to push the wedge into the log and split it.
Another method for extending the piston rod at high speed under low pressure uses an intensifier circuit. The intensifier circuit routes fluid that would otherwise flow from the cylinder’s rod end to tank back into the cap cylinder’s end. This causes the piston rod to extend rapidly, and once the wedge engages the log, a rapid increase in fluid pressure disengages the regenerative circuit, so the piston extends at a slower speed but full pressure.
Faster and simpler
DR Power Equipment, Vergennes, Vt., has an even better, and simpler solution to speed up their splitters. With conventional machines, once a log has been split, the operator removes it, retracts the cylinder, positions a new log in place, then begins another work cycle. However, DR Power’s dual-action electric log splitter uses a double-faced wedge, so the cylinder splits a log when it extends and when it retracts.
With DR Power’s splitter, once a log has been split, the operator places the next log at the other end of the spltting platform, then shifts the directional valve to split the second log while the cylinder retracts. This saves time because two logs are cut during each complete cycle instead of only one.
According to DR Power’s Jon Trobaugh, the 10-ton dual action log splitter is the only electric-gas combination wood splitter on the market. The 110-V ac motor is quiet, powerful, and allows the splitter to be used indoors. Splitting logs in a garage or basement is not only convenient, but can be done at any time because users won’t have to work in rainy, cold, or extremely hot conditions.
Ten tons of splitting force is applied by a 3-in. bore cylinder with 18½-in. stroke. The pump delivers 1.58 gpm of flow to an open center directional control valve and is capable of 3800 psi. The splitter itself handles logs up to 20-in. long and 24-in. diameter. Average cycle time is 21 sec.
The splitter can also be portable. An optional conversion kit changes its power source from electric to gas, giving the machine the ability to operate in remote areas. The engine powered version also has a 15-ton splitting capacity and is available with a trailer package, including fenders, tail lights, and ball hitch.
For more information on DR dual-action log splitters, visit www.drpower.com/logsplitters, call (802) 877-1200, or email PR@drpower.com.
Watch this video to see the DR log splitter in action.