Oil pump and balancer unit of oil pump integrated type

An oil pump-integrated balancer device comprising:

• a balancer shaft which is accommodated in a balancer housing and to which a rotation force is transmitted;
• a first power transmission member which is provided at the balancer shaft and on which a thrust force acts when transmitting the rotation force;
• a pump shaft having a second power transmission member on which the thrust force acts when the rotation force is transmitted from the first power transmission member;
• a pump element movably provided relative to the pump shaft in a rotation axis direction and performing suction and discharge of oil by the rotation force being transmitted from the pump shaft;
• a pump housing accommodating therein the pump element;
• a pair of thrust limiting portions provided at the pump shaft;
• and
• a pair of thrust receiving portions which are provided at the pump housing and which the pair of thrust limiting portions contact respectively.

An oil pump comprising:

• a pump housing accommodating therein a pump element that performs suction and discharge of oil by being driven and rotated;
• a pump shaft having a driven gear at which a thrust force occurs when transmitting a rotation force, the pump shaft being configured to be able to move relative to the pump element in an axis direction and drive the pump element by the rotation force provided from an external gear that is engaged with the driven gear;
• a first thrust limiting portion provided at the driven gear;
• a second thrust limiting portion provided at a middle position, in the axis direction, of the pump shaft and having a flange-shape;
• a first thrust receiving portion provided on an axial direction outer side surface of the pump housing and contacting the first thrust limiting portion;
• and
• a second thrust receiving portion provided inside the pump housing and contacting the second thrust limiting portion,
• wherein the second thrust receiving portion is formed at an annular recess that is recessed on an inner side surface of the pump housing toward the axial direction outer side surface of the pump housing with respect to a sliding surface of the inner side surface of the pump housing on which a side surface of the pump element located at an opposite side to the axial direction outer side surface of the pump housing slides, and
• wherein a thickness of the flange-shaped second thrust limiting portion in the axial direction is thinner than a depth of the annular recess, and the flange-shaped second thrust limiting portion is accommodated in the annular recess.