To improve pump efficiency when using rotary pumps for controlling brake fluid pressure.
Slit parts 90a to 90d are formed on the outer periphery of first to third cylinders 71a to 71c opposedly to the delivery side of the respective rotary pumps 10 and 13. Delivery pressure is introduced into these slit parts 90a to 90d. When the delivery pressure by the rotary pumps 10 and 13 is high pressure, pressure of a rotary part becomes high pressure, and acts in the direction for push-expanding end surfaces of the first to third cylinders 71a to 71c, and pressure in the slit parts 90a to 90d acts so as to negate the action. Thus, force for push-expanding the end surfaces of the first to third cylinders 71a to 71c is balanced with narrowing force so that deformation of the first to third cylinders 71a to 71c is prevented. Thus, the pump efficiency can be improved.
HARADA TOMOO
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