Magnetic rotation detection apparatus

A magnetic rotation detection apparatus comprising:

• a circuit board that includes a Hall element;
• a rotation shaft which includes a magnet at an end facing the circuit board thereof;
• a container that houses the circuit board and the rotation shaft;
• and a sealing member that seals a gap between the circuit board and an inner wall of the container;
• the container including a bearing to rotatably support the rotation shaft;
• a part of the rotation shaft protruding from the bearing and being engaged with a rotating body present outside the container;
• rotation of the magnet, which rotates along with the rotation shaft, being detected by the Hall element;
• wherein
• the rotation shaft includes a holding portion which fixes the magnet to the end such that the end and the magnet maintain a predetermined interval therebetween, the holding portion being made of molding resin such that a magnetic force of the magnet does not leak via the rotation shaft,
• a receiving member is arranged between the holding portion of the rotation shaft and the circuit board and a biasing member which biases the holding portion of the rotation shaft to the receiving member is arranged inside the container, and
• a minute gap is present between the bearing and the rotation shaft.