Vane pump

A vane pump comprising:

• a casing forming a pump chamber therein;
• a rotor arranged inside the casing to rotate eccentrically with respect to the casing;
• and
• a plurality of vanes configured to rotate with the rotor and slide on an inner side surface of the casing, wherein
• the casing is formed of a plurality of case bodies arranged in a rotation axis direction of the rotor,
• the plurality of case bodies are fastened and fixed by a fastening member so as to be in a pressure contact with each other in the rotation axis direction,
• the fastening member is arranged to extend in the rotation axis direction between both end surfaces of the pump chamber in the rotation axis direction,
• at least one of Formulas (5) and (6) is satisfied,
• m≤(b/a)×k, and Formula (5)
• m≤(c/a)×j, Formula (6)
• wherein “a” represents a height of the pump chamber in the rotation axis direction,
• wherein “b” represents a height of the rotor in the rotation axis direction,
• wherein “c” represents a height of the vane in the rotation axis direction,
• wherein “m” represents a linear expansion coefficient of the fastening member in the rotation axis direction,
• wherein “k” represents a linear expansion coefficient of the rotor in the rotation axis direction, and
• wherein “j” represents a linear expansion coefficient of the vane in the rotation axis direction.