ROTATION MEASUREMENT DEVICE AND LIQUID PRESSURE CONTROL DEVICE

To obtain a rotation measurement device and liquid pressure control device, capable of inhibiting a detection unit from being influenced by an external magnetic field, for example.SOLUTION: A rotation measurement device, as an example, comprises: a rotating magnetic field generation unit that is fixed on a rotation member driven by a motor to rotate around a rotation center, is configured in a toric shape surrounding the rotation center, includes one end and the other end in an axial direction of the rotation center and an inner peripheral surface, and generates inside the inner peripheral surface a magnetic field in a direction crossing the rotation center to make the magnetic field rotate depending on rotation of the rotation member; and a detection unit that exists between the end and the other end and is stored inside the inner peripheral surface to detect the magnetic field.SELECTED DRAWING: Figure 3 【課題】例えば、検出部が外部の磁場の影響を受けることを抑制可能な回転計測装置及び液圧制御装置を得る。【解決手段】回転計測装置は、一例として、モータの駆動により回転中心まわりに回転する回転部材に固定され、前記回転中心を取り囲む円環状に構成され、前記回転中心の軸方向の一端及び他端と、内周面と、を有し、前記内周面の内側に前記回転中心と交差する方向の磁界を生じ、前記回転部材の回転に応じて当該磁界が回転する、回転磁界発生部と、前記一端と前記他端との間にあって前記内周面の内側に収容され、前記磁界を検出する検出部と、を備える。【選択図】図３