MDD servomotors are digital AC servomotors that are used in conjunction with the manufacturer’s digital drive controllers to deliver rapid response and cost-effective automatization systems. These Rexroth servomotors are characterized by high contouring accuracies at high feed rates when they are deployed for cutting in high-speed ranges. They are synchronous in nature with electronic commutation and are excited by permanent magnets made of iron oxide or rare earth magnetic materials.

There are nine types of Rexroth MDD servomotors with varying continuous speeds and torques for a wide range of applications. The MDD 021, MDD 025 and MDD 041 series servomotors are characterized by high power density and a slender construction. The MDD 065, MDD 071, MDD 093 and MDD 115 series of servomotors also have high-power density and are deployed for highly dynamic applications. On the other hand, the MDD 090 and MDD 112 range of servomotors are used for high-precision applications where an extreme degree of precision is needed.

• MDD servomotors are used for auxiliary axes and in screwing applications, tool-changing devices, roller feeds for pressing and punching, grinding machines and nibbling machines.
• These Rexroth servomotors are characterized by a high degree of operating reliability, high-performance data, low inertia and a simple installation process.
• MDD servomotors have a completely sealed housing and IP 65 degrees of protection for their feedback and power cables that allow them to be operated directly within the working area of the associated machine, even under adverse environmental conditions.
• The servomotors encompass two sets of windings and a laminated core with permanent magnets.
• All Rexroth MDD motors except the MDD 021 series are available with or without a blocking brake. The MDD 021 series does not have a blocking brake.

MDD servomotors are available with either a plain output shaft or a shaft with a keyway as per DIN 6885-1 specifications. These motors incorporate digital servo feedback with or without a multiturn absolute encoder. They must be stored and transported only horizontally. MDD 112 and MDD 155 series of motors have tapped holes on their housings to fix lifting screws for holding the Rexroth servomotors in place when they are lifted using a lifting device.

The servomotors come with spigot nuts on their power and feedback connectors. These nuts must be screwed tightly in place when the associated cables are connected. Rexroth MDD servomotors have a high power-to-weight ratio and high overload capabilities. They have a temperature sensor in their windings to monitor their temperature and prevent overload. These servomotors come with name plates attached to their housings.