Torque-limiting nut
A torque-limiting nut is provided. The torque-limiting nut has a washer, a threaded component, and a tool interface. The threaded component has a plurality of detents and the tool interface has a corresponding plurality of recesses and a spring groove. A plurality of engagement members are sized and shaped to fit within the plurality of detents and recesses. An elastic member in the spring grooves provides a compressive force to seat the pins in the corresponding detents to frictionally couple the threaded component and tool interface. When a torque required to rotate the tool interface exceeds a predetermined value, the pin moves against the spring and unseats from the detent such that the tool interface rotates without rotating the threaded component.
1. A torque-limiting nut comprising,
a threaded component, the threaded component comprising:
a cylindrical main body having a threaded bore, an outer surface, a plurality of detents in the outer surface; and
an annular flanged portion radially extending from an end of the cylindrical main body,
a tool interface, separate from the threaded component, having an internal bore sized to receive the cylindrical main body of the threaded component, the tool interface comprising:
a plurality of recesses formed in the internal bore corresponding to the plurality of detents, each of the plurality of recesses comprising a seating groove;
a spring groove open to the recesses and the internal bore; and
an elastic member in the spring groove,
wherein each of the seating grooves receives the elastic member;
a plurality of engagement members wherein the plurality of engagement members are configured to reside, in part, in the plurality of detents and, in part, in the plurality of recesses, and
wherein, the elastic member provides a compressive force on the plurality of engagement members such that rotation of the tool interface causes the threaded component to rotate until a rotational torque applied to the tool interface exceeds a predefined torque-limit.
2. The torque-limiting nut of claim 1 wherein the each of the plurality of recesses formed in the internal bore comprise at least an engagement member seat, a radially extending recess wall, and a second recess wall.
3. The torque-limiting nut of claim 2 wherein the second recess wall is angled with respect to the radially extending recess wall.
4. The torque-limiting nut of claim 1 comprising a unitization ring and wherein the threaded component comprises a unitization channel sized to receive the unitization ring such that the unitization ring inhibits the tool interface from sliding off the cylindrical main body of the threaded component.
5. The torque-limiting nut of claim 1 wherein the elastic member comprises at least one of a spring washer, wave spring, or a die spring.
6. The torque-limiting nut of claim 1 wherein the plurality of engagement members are pins.
7. The torque-limiting nut of claim 1 wherein the plurality of engagement members are balls.
8. A torque-limiting nut comprising:
a threaded component, the threaded component comprising:
a cylindrical main body having a threaded bore, an outer surface, a plurality of detents in the outer surface; and
an annular flanged portion radially extending from an end of the cylindrical main body,
a tool interface, separate from the threaded component, having an internal bore sized to receive the cylindrical main body of the threaded component, the tool interface comprising:
a plurality of recesses formed in the internal bore corresponding to the plurality of detents, wherein the each of the plurality of recesses formed in the internal bore comprise at least an engagement member seat, a radially extending recess wall, and a second recess wall, wherein the second recess wall is angled with respect to the radially extending recess wall, and wherein the angle between the second recess wall and the radially extending recess wall is between 20 and 70 degrees;
a spring groove open to the recesses and the internal bore; and
an elastic member in the spring groove;
a plurality of engagement members wherein the plurality of engagement members are configured to reside, in part, in the plurality of detents and, in part, in the plurality of recesses, and
wherein the elastic member provides a compressive force on the plurality of engagement members such that rotation of the tool interface causes the threaded component to rotate until a rotational torque applied to the tool interface exceeds a predefined torque-limit.
9. The torque-limiting nut of claim 8 wherein the angle is between 30 and 60 degrees.
10. The torque-limiting nut of claim 9 wherein the angle is about 45 degrees.
11. A torque-limiting nut comprising:
a threaded component, the threaded component comprising:
a cylindrical main body having a threaded bore, an outer surface, a plurality of detents in the outer surface; and
an annular flanged portion radially extending from an end of the cylindrical main body,
a washer wherein the washer is coupled to the threaded component by a retaining device. wherein the retaining device comprises a groove in an outer diameter of the flanged portion of the threaded component, an aligned groove in the washer, and a retaining ring in the groove and the aligned groove;
a tool interface, separate from the threaded component, having an internal bore sized to receive the cylindrical main body of the threaded component, the tool interface comprising:
a plurality of recesses formed in the internal bore corresponding to the plurality of detents;
a spring groove open to the recesses and the internal bore; and
an elastic member in the spring groove;
a plurality of engagement members wherein the plurality of engagement members are configured to reside, in part, in the plurality of detents and, in part, in the plurality of recesses, and
where the elastic member provides a compressive force on the plurality of engagement members such that rotation of the tool interface causes the threaded component to rotate until a rotational torque applied to the tool interface exceeds a predefined torque-limit.
12. The torque-limiting nut of claim 11 wherein the washer comprises an anti-rotation device.
13. The torque-limiting nut of claim 12 where the anti-rotation device is at least one of a tang or a flat.
14. A torque-limiting nut comprising:
a threaded component, the threaded component comprising:
a cylindrical main body having a threaded bore and an outer surface; and
an annular flanged portion radially extending from an end of the cylindrical main body, the annular flanged portion having a tool interface surface comprising a plurality of spaced detents,
a tool interface, separate from the threaded component, having an internal bore sized to receive the cylindrical main body of the threaded component, the tool interface comprising a plurality of recesses corresponding to the plurality of spaced detents;
a plurality of engagement members wherein each of the plurality of engagement members comprises a ball wherein the plurality of engagement members are configured to reside, in part, in the plurality of detents and, in part, in the plurality of recesses; and
a plurality of compression members wherein each of the plurality of compression members comprises a spring in the plurality of recesses, wherein each of the plurality of compression members provides a compressive force on each of the plurality of engagement members such that rotation of the tool interface causes the threaded component to rotate until a rotational torque applied to the tool interface exceeds a predefined torque-limit.
15. The torque-limiting nut of claim 14 wherein the plurality of recesses comprise a plurality of holes.
16. The torque-limiting nut of claim 14 wherein each of the plurality of springs comprise a first end that engages a ball and a second end, opposite the first end, that engages a retaining ring.
17. A torque-limiting nut comprising:
a threaded component, the threaded component comprising:
a cylindrical main body having a threaded bore, an outer surface, a plurality of detents in the outer surface; and
an annular flanged portion radially extending from an end of the cylindrical main body,
a tool interface, separate from the threaded component, having an internal bore sized to receive the cylindrical main body of the threaded component, the tool interface comprising:
a plurality of recesses formed in the internal bore corresponding to the plurality of detents;
a spring groove open to the recesses and the internal bore; and
an elastic member in the spring groove, wherein the elastic member is a garter spring;
a plurality of engagement members wherein the plurality of engagement members are configured to reside, in part, in the plurality of detents and, in part, in the plurality of recesses, and
wherein the elastic member provides a compressive force on the plurality of engagement members such that rotation of the tool interface causes the threaded component to rotate until a rotational torque applied to the tool interface exceeds a predefined torque-limit.