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RW Motor gearboxes

RW Motor Gearboxes

We have specialized in drive systems for horticulture, livestock farming and crop storage. for over 60 years. Our motor gearboxes are extremely efficient at converting the input of an electric motor with a high rotational speed and low torque into the output of a drive system with a low rotational speed and high torque. We developed our range of motor gearboxes under the name Ridder Worm (RW).  

Some unique features of our RW motor gearboxes are:

  • Extremely long lifespan
  • Compact and powerful
  • Self-braking mechanism
  • Safe and reliable
  • Options for additional accuracy

  • Easy to install
  • A wide range of models
  • Models for specific purposes
  • Easy to program
  • High protection rating

Guaranteed quality

Our RW motor gearboxes have proved themselves in the field over many years of use. More than 450,000 Ridder motors operate worldwide on a daily basis. And should you experience a problem with one of our motors, we’ll make sure it’s quickly replaced, because we know you rely on our equipment every day. Thanks to our meticulous purchasing methods, extensive testing procedures and streamlined production process, we’re able to guarantee the highest possible quality. Even small details, such as using a powder coating, help ensure our motors stand out from the competition.

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Self-braking worm wheel transmission

The gear unit of a RW motor gearbox consists of a combination of perfectly matched worm gear and worm wheel transmissions, resulting in near silent operation. This self-braking worm wheel transmission ensures that the drive shaft is braked when the drive system stops moving. The compact design of the RW motor gearboxes means that they are only suitable for intermittent operation.

RSU limit switch systems

The RSU limit switch is invented by Ridder. The RSU makes it a breeze to program the start and end positions of the driven system. The RSU limit switch system features a unique switch spring mechanism, which allows the required RSU limit switch system to be used for each RW motor gearbox model. The switching distance between the duty and safety switches has also been carefully selected for each RW model, ensuring safe, accurate and reliable operation.

Options for additional accuracy

In 2011, we launched a digital position sensor called the Ridder PositioningUnit (RPU). This sensor enables the positions of a driven ventilation, screen or hoisting system to be monitored with extreme precision and fed back to a climate computer with a 4-20mA signal. The RPU is suitable for use with new and already installed Ridder RW motor gearboxes. Since the RPU uses non-contact measuring technology, the feedback value remains constant at all times.

Easy to install

RW motor gearboxes are easy to install. They come standard with the necessary fixing bolts and spring washers. We also provide a wide range of mounting plates designed specifically for the driven system. All RW motor gearboxes feature two output shafts with sprockets or winch shafts. The RW motor gearbox is connected to the drive shafts of the driven system with a chain coupling set. This allows undesirable effects, such as small angle differences or alignment errors, to be compensated for. 


A wide range of models

Ridder RW motor gearboxes are available in a wide range of sizes and models. They are suitable for application worldwide since they use tropic-proof electric motors (IP55) with various phases, supply voltages, mains frequencies and quality marks. 

 Click for more information about our RW Motor Gearboxes models

Standard motor gearboxes
Our RW motor gearboxes are compact, maintenance-free drive units for operating ventilation and screen systems in greenhouses and livestock houses. These easy-to-install motor gearboxes are enclosed in a housing with a sealed limit switch system


Dust-proof and spray-proof motor gearboxes (IP55)
RW motor gearboxes are available with a high protection rating of IP55 for use in livestock houses. They are designed to operate at ambient temperatures of 0-40 °C.

Motor gearboxes with belt or cable drum (L)
Equipped with a winch or belt drum, RW-L motor gearboxes are compact, maintenance-free drive units for hoisting feeding and drinking lines, and opening air inlets in livestock houses. These easy-to-install motor gearboxes are enclosed in a housing with a sealed limit switch system that has a high protection rating of IP55. RW-L motor gearboxes are designed to operate at ambient temperatures of 0-40 °C.

Motor gearboxes with special bearing-mounted drive shaft (TRA)
Our RW-TRA motor gearboxes (RW45TRA and RW240)  are compact, maintenance-free drive units for rack-driven ventilation and hoisting systems in livestock houses. RW-TRA motor gearboxes differ from the standard models in that they are equipped with a special bearing-mounted drive shaft which uses a pinion house unit to drive the TR520A rack drive. 

Motor gearboxes with continuous worm shaft (D)
Equipped with a continuous worm shaft, RW-D motor gearboxes are compact, maintenance-free drive units for operating ventilation and hoisting systems in livestock houses. The continuous worm shaft makes it possible to drive a worm wheel gearbox, allowing extra functionality to be added. 

Motor gearboxes for screen purposes (S)
Ridder has developed more powerful motor gearboxes (RW1200/ RW1600), specifically for screen purposes. These motor gearboxes are indicated by the addition of the letter 'S'. Deciding which motor gearbox will best suit your needs depends on the size and weight of the screen.

motor gearboxes (F)
A frequency-controlled electric motor is used for applications where high demands are placed on climate control, such as the need to open and close vents or screens rapidly. In standard situations, the system is driven at a low frequency or speed, while in other situations a higher frequency is used. Since all electronic components are potted, they have a high protection rating of IP65 for excellent resistance to water and vibration. RW-F motor gearboxes come fully pre-programmed.

Motor gearboxes for indirect ventilation
systems (34/68/ 81) (860)
The RW70/100/140/200-34/68/32 motor gearboxes have been designed especially for indirect ventilation systems. The output shafts of these motor gearboxes have a higher rotational speed (n/min= 34, 68 or 82) and have a maximum switching range of 860 revolutions. These ventilation motors are combined with worm wheel gearboxes in order to create an indirect ventilation system (a system which drives multiple air vents with one motor). The higher rotational speed is reduced again by the transmission ratio of the worm wheel gearboxes (i=35). 

Motor gearboxes with 12-tooth chain coupling (z12)
RW motor gearboxes come standard with a 16-tooth chain coupling. However, to compensate for large angle differences (up to 8°), they can also be supplied with a 12-tooth chain coupling. 

Motor gearboxes suitable for LogicLink concept
RW motor gearboxes can also be supplied with LogicLink control units. These units feature mechanical and control components that are designed to work together perfectly. This has major advantages in terms of installation and functionality. 

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