Latest from SEW-EURODRIVE is an exciting range of planetary gear units – the SEW PPK and SEW P2.e series. Built to provide the key benefits that SEW planetary gear units are renowned for – compact design for space-constrained conditions, along with high torque and low-speed outputs – the range complements the existing lines and offers innovative capabilities in new industrial applications.
“The launch of the SEW PPK and SEW P2.e series speaks directly to our ‘closing the loop’ strategy,” explains Edwin Weyers, Business Development Manager for Projects at SEW-EURODRIVE. “Traditionally, the existing P-series was our flagship offering, but it was somehow limited in terms of sizes and application areas. In addition, we have always offered our large-scale, custom-built XP-series. Through our 90 years of experience in developing and constructing gear units, we realised that there was need for a small and medium-sized range to close the gap between the P-series and the larger XP-series.”
SEW PPK
The SEW PPK planetary gear units complement SEW-EURODRIVE’s product line in the torque load range under the proven P-series. Offering a torque range from 10 to 18 kNm, the SEW PPK covers a gear ratio range from 65 to 390:1. The ratio can be further reduced by adding a primary reducer before the planetary head, allowing for ratios up to 10 650:1 for a much lower speed capability.
With the SEW PPK, the load is distributed across multiple planet gears, resulting in significantly higher power density and thus enabling smaller dimensions compared with other gear unit types. This makes the range perfect for all heavy-duty applications that require a robust, compact design and high gear ratios.
In addition to gear unit design such as flange and foot mounting, the variance at the input and output offers great flexibility for the end user. On the output end, a solid shaft with key and a splined solid shaft are available.
When looking for a hollow shaft gear unit, customers can choose between a splined hollow shaft and a hollow shaft with shrink disk. On the input gear end, the motor connection is made either via an exposed shaft-end or a motor adapter. Access to the complete modular motor system from SEW-EURODRIVE with extensive options such as brakes and encoders also offers further degrees of freedom.
SEW P2.e
Available with torque ratings from 2 to 124 kNm, the SEW P2.e range covers gear ratios from 15,2 to 332:1. While most planetary gearboxes have a three-stage design only, the SEW P2.e can also be supplied in a two-stage model. The SEW P2.e encompasses all the benefits of the SEW PPK, but goes a step further with a broader spectrum of diversity in its speed – up to 100 rpm – as well as in ratio and torque.
The high-strength, durable materials with advanced heat treatment allow the gear units to withstand extreme loads and resist wear, thus making light work of high torque requirements. “The gears are engineered for high torque capacity with robust, precise teeth to handle intense forces efficiently,” says Weyers.
“In essence, these planetary gear systems produce high torque by distributing the load across several gears and using gear ratios to multiply the input torque. The efficient and compact design allows for the high torque to come from a relatively small package,” adds Weyers.
With this compact design, coupled with its flexibility and high thermal limit rating, this gear unit is ideally suited for continuous heavy duty applications where space is at a premium. Typical applications for the SEW P2.e in the mining and quarrying industry include crushers, apron feeders, clarifiers and thickeners. Other industrial applications range from screw presses and slewing gears to wood panel shredders, ring pan mixers and batch plants, amongst others.
One of the major talking points is the exceptional thermal limit rating, which is made possible by the integrated fan in the motor interface. The fan aspirates air radially, accelerates it and generates a cooling stream of air with a high flow rate.
“The SEW P2.e is the only planetary gear unit on the market with an integrated fan coupled directly between the motor and the planetary head. Consequently, it boasts a large cooling area (two to four times larger than some of the competitor offerings in this size class) – a condition which is central to the high thermal limit rating. Despite its high power density, the SEW P2.e series therefore boasts a best-in-class thermal limit rating,” explains Weyers.
The direct bearing system, which is completely different to traditional planetaries, puts the SEW P2.e in a league of its own. “With the direct bearing system, we do away with the outer ring, which results in a more compact solution and longer bearing life. Doing away with the outer ring allows for the installation of much larger bearings in a compact space, thus improving the service life of gears,” explains Weyers.
Compared with predecessor units, the SEW P2.e comes with variable motor interfaces. The direct motor mounting means there is no need for the motor adapter flange that is otherwise normally required – so this is a particularly space-saving design. “The direct motor mounting allows for installation of bigger motors. In addition, the various input adapters help with a high level of flexibility to meet varying customer requirements,” says Weyers.
Reduced weight is another major benefit of going the SEW P2.e route. With its lightweight gear unit design, the SEW P2.e is 24% lighter and 10% shorter in length, compared with some of the same-sized units on the market.
While the SEW P2.e benefits from several upgrades, SEW-EURODRIVE has been careful to retain the same critical dimensions as previous SEW P-series unit models. This allows customers to easily migrate to the SEW P2.e units without having to alter their operating environment or existing infrastructure.
“Our SEW planetary gear units work on a modular system. Parts’ commonality across ranges is a common feature. For example, the new SEW P2.e shares the same parts with the previous P-series and XP-series ranges. This increases operational flexibility and reduces procurement, logistical and training costs for customers,” says Weyers.
Lubricants
Given its nearly century experience in developing and constructing gear units for numerous customer applications, SEW-EURODRIVE has over the years amassed vast tribological expertise. Based on this and the results of long-term testing, the company has developed a special formulation for its premium gear unit lubricants.
GearOil by SEW-EURODRIVE increases the performance of SEW EURODRIVE gear units – be they standard, servo or industrial. It reduces friction between the gear wheels because it develops an outstanding lubrication film that increases the service life of the lubricant itself, as well as that of wear parts such as sealing rings and bearings. In addition, it protects gear units from corrosion and also from oil foaming damage. The self-cleaning properties of the lubricants prevent deposits as they bind water and dirt particles.
“By using our premium gear unit lubricants, end users have peace of mind that their investments are protected – a high level of resistance to ageing reduces wear and increases service life. Customers can expect up to 50% longer service intervals and a long shelf life of up six years if they are using the special SEW-EURODRIVE approved lubricants,” says Weyers.
“Collectively, these features – the unique bearing design, direct mounting of motors, high torque, high thermal limit rating and our own SEW lubricants – demonstrate that the SEW gear units can effectively manage demanding conditions in quarrying and mining, which are characterised by dust, vibration and high loads, while, all the while, maintaining high performance and reliability,” concludes Weyers.
