Five things to consider when deciding on the right gerotor and Geroler motor for your needs

1. Performance

It is always a good idea to ask for mechanical and volumetric efficiency data, but make sure the test data is over an extended period of time. Many manufacturers tune performance to peak in the first few hours of operation, but then degrade quickly. Performance that degrades quickly will not do your machine or your customer justice. Compare apples to apples. Hydraulic motor performance data is not standardized. Be wary of ratings and test data that do not include all the performance test parameters. [A performance rating without an oil viscosity is worthless." Consider the performance of not just the product, but also the team of support. Will they deliver the product on-time? Will they provide support in critical times?

2. Quality

Does the manufacturer have a history of consistent quality? Ask for the quality data and let the data speak. Some manufacturers do not have the process controls to ensure repeatable performance. Gerotor and Geroler motor grinding is not all the same. Grinding star profiles outside the capabilities of the form grinding machine will cause inconsistent results. What are the impacts of decreased product quality on your business`s reputation? Look for a manufacturer that focuses on using high-quality materials and follows industry standard manufacturing processes. Some manufacturers decrease the cost of their product by using inferior materials or speeding up processes like heat treating and form grinding. Consider warranty options. Does the manufacturer you choose have a 2-3 year standard warranty? If not, why?

3. Reliability

Reliability is quality over time.Your machine needs both. Look for a manufacturer that has a track record of being reputable. In this game it`s true that history is the best predictor of the future. Can you count on the manufacturer to be a leader in technological innovations? With the time, effort and resources you`re putting into developing your machine, make sure you`re partnering with a manufacturer that can help position your business as a leader in the industry. Consider where the motor is made. Is it American-made? Can you rely on the manufacturing materials used and standards practiced in the manufacturing location?

4. Support

Consider the long-term relationship of your business and the manufacturer. Will you get the support you need now and in the future? A product is only as good as the support system that surrounds it. Investigate the manufacturer`s options for additional support. Would you benefit from CAD modeling support or the creation of a custom solution? Remember custom solutions will differentiate your machine from the competitor. Do you just want a part or do you want a system of solutions? Some manufacturers have the know-how and resources to provide a custom system of solutions for your machine. Others can provide a singular part but may not have the capabilities to provide insight and recommendations on improving the machine`s design.

5. Cost

Obviously cost is very important. However cost is really a function of all the previous above items. Sacrificing the above items can provide a lower cost, but what will that do to your machine and your customer when issues arise? Some manufacturers try to keep costs low by having a [one size fits all" approach to their motor portfolio; however this compromise often leaves you with a solution that really does not work the way it should on your machine. Look for quality products that fits your application, rather than the cheapest option that will likely need to be replaced more frequently.

There`s certainly no shortage of things to consider when choosing the best gerotor and Geroler motor for your needs. As you consider your options, think of Eaton. With the broadest and most unique Geroler Motors portfolio in the industry as well as a team that provides unsurpassed support in modeling and custom solutions, Eaton is the manufacturer with the history and expertise you can feel proud to partner with.

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MAY 18, 2018

WHITNEY VANKLAVEREN

From construction to agricultural equipment and the vocational truck industry, motors can essentially be used for any application requiring rotary power including food-processing equipment, augers, and countless others which impact our daily lives. Not all applications require rotary power and therefore the use of a motor, but for those applications requiring low speeds and high torque-such as rotating a cement mixer to pour concrete or a feed spreader distributing seed to plant crops-a low-speed, high-torque motor will be essential.

This is because within these types of applications, the load being placed upon the equipment is very heavy and thus, requires a greater amount of torque to start up from its stationary position and to operate at lower speeds. In these instances, more torque is required than a typical Gear Pump can provide. To generate the torque required for these low-speed, high-torque applications, a motor is used encompassing a rotor assembly with either a gerotor or roller gerotor design. As a result, it`s important to understand these two designs to determine the option best suited for the requirements of the given application.

GEROTOR DESIGN

Motors with a gerotor design are smaller, more compact in size and typically used for light-duty and low-pressure applications. Within this type of motor design, the rotor assembly consists of a stationary ring called the stator and a moving, planetary gear-the rotor. The stator is machined into the metal housing, which the rotor-a star-shaped gear-sets into, and its wall utilized to form the motor`s displacement chambers. As the oil enters the rotor assembly within a gerotor design, passing through the pressure zones from high to low, it forces the rotor to turn within the stator-moving against one another-to convert the fluid power into rotary power as torque.

While the gerotor design can suit the needs of various applications and is an economical option, it does have a looser tolerance and cannot force the gear as hard due to the gaps naturally resulting from how the stator and rotor fit together. These gaps allow more oil to pass from high to low pressure, resulting in greater slippage and less converted torque. The rotor and stator moving against one another within the gerotor design can lead to wear over time, which is why for medium/heavy-duty and high–pressure applications requiring a more robust option there is a roller gerotor design.

ROLLER GEROTOR DESIGN

A roller gerotor design functions the same as a gerotor design as oil forces the rotor to turn within the stator converting fluid power into rotary power as torque; however, there is one main difference within the rotor assembly. Instead of using the stator`s wall, the roller gerotor design incorporates roller pins to form the displacement chambers. Its these roller pins that eliminate the gaps found within the gerotor design for a tighter fit and tighter tolerance, allowing less oil to pass through in order to force the gear harder and ultimately convert more torque. Motors featuring a roller gerotor design are more robust, built to better withstand wear, and traditionally last longer and perform better; however, there is an added cost associated with these benefits.

For this reason, it`s imperative to weigh all the available options – having a clear understanding of the low-speed, high-torque application`s requirements and the two types of motor design before making a purchase. In the end, you may find that the gerotor design-an economical alternative-is all that`s needed or the more robust, roller gerotor design`s benefits outweigh the added cost.