All sanitary approved pumps must have an open yoke between the pump housing and the motor. Here are examples of different pumps.
The reason for the space in the open yoke is to avoid contamination if the seal leaks. In the case of a close coupled pump, if the seal leaks the space between the pump and the motor fills with product that can then spoil and contaminate your product. With an open yoke sanitary pump if the seal leaks the leakage drains away, is obvious and is easy to clean up. It is good and even recommended to hose this area often to keep it clean.