Constant-flow pulseless rotary-vane-type displacement machine

A machine, comprising:

• a shaft member;
• a rotor that rotates about a rotor central axis with the shaft member and has a plurality of slits formed at an even interval of a constant angle (α), the plurality of slits being opened to an outer circumference;
• a cam ring having an inner-circumferential-surface having a smooth closed curve in which a distance from the rotor central axis increases and decreases once or a plurality of times during one rotation around the rotor;
• a plurality of vanes each slidably fitted into the corresponding slits in the rotor, a distal end of each vane being biased to be in constant contact with the inner circumferential surface of the cam ring;
• two side plates that each close each opening portion of the cam ring in an axial direction;
• and
• a bearing member that is integrated with or fixed to the side plates and rotatably supports the shaft member, wherein
• the machine is configured to function as a liquid pump or a hydraulic motor by increasing or decreasing each of a plurality of working space volumes surrounded by the cam ring, the rotor, the two side plates, and the adjacent vanes in accordance with a rotation of the rotor and the shaft member,
• the inner-circumferential-surface of the cam ring comprises one or plural pairs of large and small circular arc portions which are defined by large and small constant distances from the rotor central axis, respectively, the large constant distance being larger than the small constant distance, each central angle (β) of the large and small circular arc portions around the rotor central axis being 0.9 times or more of the constant angle (α) between the adjacent slits, and
• the inner-circumferential-surface of the cam ring further comprises interval circular arc portions connecting the large circular arc portion and the small circular arc portion therebetween, a profile of at least one of the interval circular arc portions being defined by a function (R(θp)) of a distance (R) from the rotor central axis with respect to a central deflection angle (θp) around the rotor central axis, and
• the profile of the inner-circumferential-surface satisfies the following requirement:
• when a curve obtained by differentiating the function (R(θp)) by the central deflection angle (θp) becomes zero at both ends of each interval circular arc portion and has two inflection points inside the ends.

A machine, comprising:

• a shaft member;
• a rotor that rotates about a rotor central axis with the shaft member and has a plurality of slits formed at an even interval of a constant angle (α), the plurality of slits being opened to an outer circumference;
• a cam ring having an inner-circumferential-surface having a smooth closed curve in which a distance from the rotor central axis increases and decreases once or a plurality of times during one rotation around the rotor;
• a plurality of vanes each slidably fitted into the corresponding slits in the rotor, a distal end of each vane being biased to be in constant contact with the inner circumferential surface of the cam ring, the distal end of each vane being defined by a circular arc, a slit direction displacement (L) being defined as a distance from the rotor central axis to a center of the circular arc of each vane;
• two side plates that each close each opening portion of the cam ring in an axial direction;
• and
• a bearing member that is integrated with or fixed to the side plates and rotatably supports the shaft member, wherein
• the machine is configured to function as a liquid pump or a hydraulic motor by increasing or decreasing each of a plurality of working space volumes surrounded by the cam ring, the rotor, the two side plates, and the adjacent vanes in accordance with a rotation of the rotor and the shaft member,
• the inner-circumferential-surface of the cam ring comprises one or plural pairs of large and small circular arc portions which are defined by large and small constant distances from the rotor central axis, respectively, the large constant distance being larger than the small constant distance, each central angle (β) of the large and small circular arc portions around the rotor central axis being 0.9 times or more of the constant angle (α) between the adjacent slits, and
• the inner-circumferential-surface of the cam ring further comprises interval circular arc portions connecting the large circular arc portion and the small circular arc portion therebetween, a profile of at least one of the interval circular arc portions being defined by a function (L(θr)) of the slit direction displacement (L) with respect to a central deflection angle (θr) around the rotor central axis, and
• the profile of the inner-circumferential-surface satisfies the following requirement:
• when a curve obtained by differentiating the function (L(θr)) by the central deflection angle (θr) becomes zero at both ends of each interval circular arc portion and has two inflection points inside the ends.

A machine, comprising:

• a shaft member;
• a rotor that rotates about a rotor central axis with the shaft member and has a plurality of slits formed at an even interval of a constant angle (α), the plurality of slits being opened to an outer circumference;
• a cam ring having an inner-circumferential-surface having a smooth closed curve in which a distance from the rotor central axis increases and decreases once or a plurality of times during one rotation around the rotor;
• a plurality of vanes each slidably fitted into the corresponding slits in the rotor, a distal end of each vane being biased to be in constant contact with the inner circumferential surface of the cam ring, the distal end of each vane being defined by a circular arc, a slit direction displacement (L) being defined as a distance from the rotor central axis to a center of the circular arc of each vane;
• two side plates that each close each opening portion of the cam ring in an axial direction;
• and
• a bearing member that is integrated with or fixed to the side plates and rotatably supports the shaft member, wherein
• the machine is configured to function as a liquid pump or a hydraulic motor by increasing or decreasing each of a plurality of working space volumes surrounded by the cam ring, the rotor, the two side plates, and the adjacent vanes in accordance with a rotation of the rotor and the shaft member,
• the inner-circumferential-surface of the cam ring comprises one or plural pairs of large and small circular arc portions which are defined by large and small constant distances from the rotor central axis, respectively, the large constant distance being larger than the small constant distance, the small arc portion being defined by a small constant distance smaller than the large constant distance, each central angle (β) of the large and small circular arc portions around the rotor central axis being 0.9 times or more of the constant angle (α) between the adjacent slits,
• the inner-circumferential-surface of the cam ring further comprises interval circular arc portions connecting the large circular arc portion and the small circular arc portion therebetween, at least one of the interval circular arc portions comprising a first portion, a second portion, and a third portion that are smoothly connected to each other in this order, the first, second, third portions being defined by first, second, and third central angles (γ1, γ2 and γ3) around the rotor central axis, respectively,
• the first central angle (γ1) and the third central angle (γ3) are equal to each other or one of the first central angle (γ1) and the third central angle (γ3) is in a range of from 0.9 times to 1.1 times of the other, and
• a profile of the second portion is defined by a function (L(θr)) of the slit direction displacement (L) with respect to a central deflection angle (θr) around the rotor central axis and satisfies the following requirement:
• the function (L(θr)) within the second central angle (γ2) is substantially a linear function.