Choosing the right motor for Maximum efficiency

The ideal in hydraulic system design is to match overall efficiencies to the application performance expectation. This requires MTL Attachments to first match the motor, then to a specific system performance expectation. GPM - PSI - RPM - Overall Tip speed - Cutting Application - type of use.

Both motor types—gear or piston—has a specific performance profile advantages and disadvantages. So, knowing the application performance requirement and which motor type best meets the objective is the first step. Then it’s necessary to evaluate the cost of your motor options vs the applications being used for.

In the end, it all goes back to the application’s performance expectations. Some have a harsher more severe duty cycles, while others do not. If, for example, you consider running a std flow Gear type in a high impact more than 1.5 hours of continuous use application, the life of the motor will be less than the life of a Higher Flow Rated Gear motor that is designed to operate in those types of environments. It is important to understand what operating pressures and flows are required for the motor selected to achieve the application performance expectations, this is where MTL Attachments surpasses all of our competitors - we have the experience of thousands and thousands of cutters vs model of skid steer - vs applicational use, We match your needs the best we can to your type of requirements - Both Piston and Gear type.

Each motor type has its own set of applications where they are a better choice than others. For example, if a small gear motor designed to operate at a max of 3,000 psi and 700 rpm is put into an application that requires it to run consistently at 3,000 psi and 700 rpm, the motor will be running in a maximum over-stressed condition and have a reduced life—even though it is technically within its ratings. The better motor choice would be a motor with higher ratings that will live longer in the application. Granted, there is a greater cost in going with a higher rated motor. The final decision always will depend on what is required in terms of application performance and motor life versus where you want to be with cost.

Gear Motors

Come in two varieties—the gerotor/geroller or orbital and external spur gear designs. Orbital styles are classified as LSHT motors; They consist of a matched gear set enclosed in a housing. When hydraulic fluid is moved into the motor, it causes the gears to rotate. One of the gears is connected to the motor output shaft, which produces the motor’s rotary motion. Key features include:

Key features of Gear motors:

• low weight and size
• Maximum longevity
• Long History of durability
• lower cost
• wide range of speeds

Cons for Gear Type Motors

• Cutting times are 60% to 70% of The Piston options (depending on cooling efficiency of your skid steer- most gear type motors can operate up to 2 hrs straight at WOT - wide open throttle / full power before needing to cool down) - i.e. Gear Motor cutting at 23 gpm at 80 degrees temp, in a high stress environment would be approx 2 hours of straight use before needing to cool down to provide maximum efficiency again.

PISTON Motors

Piston motors offer extremely high mechanical efficiencies, up to 98%

Radial piston motors, such as the Industry leading - SAI-FS series motors are LSHT (low speed High Torque) classified. These motors are designed with pistons arranged perpendicular to the output shaft. Typically, the pistons will ride against a cam, which is mechanically connected to the output shaft. The pistons will force the cam to rotate as hydraulic fluid enters the motor.

These motors are capable of producing high torques at low speeds, down to half a revolution per minute.
Applications include Drum and Disc Mulchers in the forestry equipment industry..

Key features of radial piston motors:

• Higher output torques
• Faster Recovery times than the Gaer type
• smoother output speed at low speeds (no “cogging”)
• Longer Cut times with a higher dissipation of heat exchange
• More efficiency delivers more usable power

Cons for PISTON Type Motors

• Piston motors CAN NOT be stalled - causing a piston type motor to come to an abrupt stop could cause a safety oil seal to relieve and need to be replaced before continuing use. - Typically less than 45 min and $40 to $60 if using the High Pressure VITON style double lip seal. See update below for our MTL cutters upgrade as of 2021.

*******Atmosperic Vent Valve - MTL cutters only - as of 2021 we now started using the AV vent on all our piston motors that now prevent the lower seal from ever blowing - this is a game changer and a result of a constant strive for improvements that we try to achieve here at MTL.******

*****Manual “H” Valve models use an external circulatory valve to provide the highest amount of power and torque yield and have been widely used in Cutters for many years - yet are more susceptible to the stalling issue if abused or continual lack of regard for rpm maintaining.
*****Automated valve models provide some extra safety layers to the stalling issue but do not provide a 100% uncertainty. Using both pressure and return relief valves they use a small percentage of the power available to provide a high percentage of stalling situations, results are extremely impressive - yet the cost is slightly higher than the circulatory valve option.

• Piston motors require a case drain option, these types of motor MUST vent pressure build up via the case drain line - failure of the case drain line would result in the safety seal relief on the motor. ALL Hydraulic lines MUST be connected and remain connected during any and all use (if the cutter is turning - the lines must stay connected - even if the machine is shut off and you are out of the cab) Damaged, Pinched, disconnected or defective couplers can result in the safety valve replacement .

All safety valve replacements are NOT covered under warranty - this is an indicator that the unit has been put in a situation mentioned above- While this is listed as a CON for the PISTON models - one may think of this as the ultimate PRO or insurance policy for the motors, offering protection to the motor in every possible unforeseen situation - yet not causing catastrophic damage to your motor.

Summary of Piston vs Gear Motors

Think of a PISTON motor much like that of a centrifugal clutch on a chain saw, a motor with very high output and very quick recovery spin up times, just like the chain saw - should you stall or run down in RPM to much you will cease to have any power or output. This option provides the absolute highest and most efficient hydraulic power conversion to horse power available on the market to date. Commercial, experienced or operators that have a great attention to details and surroundings find this to be the only option they will consider, with the AV VENT we run now as of 2021 on all MTL piston motors even homeowners or first timers can experience the ABSOLUTE best power advantages offered in the industry.

Think of a GEAR Motor much like that of a Air Cooled Diesel Engine - A workhorse - Plain and simple operation - no speedster - not the ultra fast recovery times of the Piston - Not the HP output of the Piston and - Not the efficient heat dissipation of the Piston - but the longest proven track record of reliable continuous use motors in various industries - as long as it is not over-stressed by extreme heat fatigue of prolonged cutting times. This Gear Motor option requires the least amount of attention to detail, listening for RPM declines, hose or coupler issues etc. Homeowners, weekend users, first time no experience users and Commercial users where prolonged cutting times are not an issue would most likely be the obvious choice, now since March of 2021 we have included our AV vent on all Piston Motors and developed basically a bulletproof Piston Option on our cutters allowing ALL customers to experience the best motors in the industry.

MTL Attachments cutters

At MTL Attachments we go further than other companies to match your attachment to your application, we have hydraulic options for nearly every application , free flow, automated valves, antivaitation, external , internal , check low, check high, sizes 9-10-12-14 and 16 body couplers, 1/2”-3/4 “or even 1” supply lines optional. Let us do what we do best, after your online website purchase of a cutter - typically within 7-10 business days we will contact you and go over your complete order to make sure your getting exactly what works best for your Machine and type of use combination. Giving you multiple possibilities in most cases to provide you with a cutter best suited for your need. Every cutter goes to hydraulics in our shop before shipping out where the options we have can be applied to your unit - please be patient the demand for our cutters grows every year and and the production times to build over 200+ cutters a month are at an all time high of nearly 10 business days from order to ship completion. Some times of the year this may be less or more depending on the season, demand and our partner supply vendors for the parts required to build one of the best cutters in the industry.