Hydraulic device

A hydraulic device comprising:

• a tool unit having a hydraulic pump for generating pressure oil by rotation of a rotary member, a first rotary shaft connected to the rotary member, and a tool that operates by the pressure oil generated by the hydraulic pump;
• and
• a driving unit having a motor for driving rotation of the rotary member of the hydraulic pump, and a second rotary shaft rotated by the motor, the driving unit being detachably mounted to the tool unit, wherein
• a connected portion is disposed at an end of one of the first rotary shaft of the tool unit and the second rotary shaft of the driving unit, and a connecting portion which is connected to the connected portion is disposed at an end of the other one of the first rotary shaft of the tool unit and the second rotary shaft of the driving unit,
• the connected portion has a guide shaft that rotates integrally with the first rotary shaft or the second rotary shaft, wherein the guide shaft is cylindrical and the cross section of the guide hole is circular, and a plurality of three or more engaged portions disposed around the guide shaft, wherein the engaged portions are positioned symmetrically with respect to the axis center of the guide shaft, and wherein the engaged portions are equally spaced to line up along the circumferential direction of the guide shaft such that in a case where the guide shaft is pushed toward the inside of the guide hole, even if the engaged portions are not aligned with the engaging portions, the connected portion rotates relative to the connecting portion such that, by contact of a tapered surface disposed at the end of each engaged portion with the outer circumferential edge of the engaging portion, the misalignment of the engaged portions relative to the engaging portions is corrected, and therefore, when the guide shaft has been pushed deeply into the guide hole, each engaged portion is fully inserted into the engaging portion,
• the connecting portion has a guide hole into which the guide shaft is inserted, and engaging portions with which the engaged portions are engaged and which are disposed around the guide hole,
• each engaged portion is a conical projection, and each engaging portion is a recess into which the conical projection fits,
• a tip of each conical projection is tilted relative to a longitudinal direction of the guide shaft, and is tiled relative to a surface orthogonal to the longitudinal direction of the guide shaft,
• the hydraulic pump has an oil chamber, an eccentric portion attached to the end of a rod-like rotary member, and a piston that moves upward and downward by rotation of the eccentric portion, the eccentric portion is eccentric relative to the axis of the rotary member, and a bearing is attached to the outer circumferential surface of the eccentric portion, the piston is constantly pressed toward the outer circumferential surface of the bearing by a spring, and therefore, when the rotary member rotates, the eccentric portion and the bearing rotate eccentrically relative to the axis of the rotary member, whereby the piston moves upward and downward, and pressure oil is sent from the oil chamber toward the tool, to operate the tool,
• an outer circumferential edge of each engaging portion in the end surface of the connecting portion is chamfered so as to be angled by about 45° relative to the end surface of the connecting portion, thereby in a case where the connected portion is to be connected to the connecting portion, when the guide shaft is inserted in the guide hole and the guide shaft is thereafter pushed toward the inside of the guide hole, the engaged portions are inserted into the respective engaging portions, and in a case where the guide shaft is pushed toward the inside of the guide hole, even if the engaged portions are not aligned with the engaging portions, the connected portion rotates relative to the connecting portion such that, by contact of the tapered surface disposed at the end of each engaged portion with the outer circumferential edge of the engaging portion, the misalignment of the engaged portions relative to the engaging portions is corrected, and
• the hydraulic device further includes a locking mechanism for fixing the tool unit and the driving unit with respect to the axial direction of the rotary member and the rotary shaft so as to maintain connection of the connected portion of the driving unit to the connecting portion of the tool unit.