1. A variable displacement vane pump, comprising:
a control ring pivotable between a first position wherein the pump has a maximum displacement and a second position wherein the pump has a minimum displacement;
a feedback mechanism responsive to the output pressure of the pump to move the control ring from the first position towards the second position in response to increases in the output pressure of the pump; and
a control spring biasing the control ring towards the first position, the longitudinal axis of the control spring being inclined at an angle of from about ten degrees to about eighty degrees with respect to a plane passing through the rotational axis about which the control ring pivots and the contact point between the control ring and the control spring.
2. A variable displacement pump according to claim 1 wherein the longitudinal axis of the control spring being inclined at an angle of from about twenty-five degrees to about sixty-five degrees when the control ring is in the first position.
3. A variable displacement pump according to claim 1 wherein the longitudinal axis of the control spring being inclined at an angle of from about thirty-five degrees to about fifty-five degrees when the control ring is in the first position.
4. A variable displacement pump according to claim 1 wherein the longitudinal axis of the control spring being inclined at an angle of from about forty degrees to about fifty degrees when the control ring is in the first position.
5. A variable displacement pump according to claim 1 wherein the control spring engages the control ring through a protrusion on the control ring, the protrusion having a curved surface allowing the protrusion to move across the end of the control spring.
6. A variable displacement pump according to claim 1 further comprising a spring cap over the end of the control spring, the spring cap engaging a protrusion on the control ring, the protrusion having a curved surface allowing the protrusion to move across the end of the spring cap.
7. A variable displacement pump according to claim 1 further comprising a spring cap over the end of the control spring, the spring cap engaging a protrusion on the control ring, and one of the protrusion and spring cap having a bearing surface allowing the protrusion to move across the end of the spring cap.
8. A variable displacement vane pump operable to provide a substantially constant output, independent of pump operating speed increases, when the pump is in its regulated operating region, the pump comprising:
a control ring pivotable between a first position wherein the pump has a maximum displacement and a second position wherein the pump has a minimum displacement;
a feedback mechanism responsive to the output pressure of the pump to move the control ring from the first position towards the second position in response to increases in the output pressure of the pump; and
a control spring biasing the control ring towards the first position, wherein the control spring is oriented with respect to a plane, extending through the rotational axis about which the control ring pivots and the contact point between the control ring and the spring, such that the moment arm of the control spring force about the point where the control ring pivots decreases as the control ring pivots towards the second position.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A porous titanium having a low contact resistance comprising:
a porous titanium body having a skeletal structure and continuous holes that opens on an outer surface of the porous titanium body and are connected to each other to form inner holes;
an Au network formed on at least an outer surface of the skeletal structure of the porous titanium body as a continuous network structure by adhering and diffusion bonding Au on the outer surface of the skeletal structure; and
Ti oxide layers formed in clearances between adjacent Au cords of the Au network.
2. The porous titanium having a low contact resistance according to claim 1, wherein the width of at least a part of each of the Au cords of the Au network is 0.3 to 10 \u03bcm.
3. The porous titanium having a low contact resistance according to claim 1, wherein the thickness of the Ti oxide layer formed in the clearance between adjacent Au cords of the Au network is 30 to 150 nm.
4. The porous titanium having a low contact resistance according to claim 2, wherein the thickness of the Ti oxide layer formed in the clearance between adjacent Au cords of the Au network is 30 to 150 nm.