DEVICE WITH A HIGH-TEMPERATURE INDICATOR FOR A WHEEL-END SYSTEM
A device for a wheel-end system includes a component that defines a rotation axis and forms (i) a pocket extending axially downward from a top face of the component and (ii) a shaft extending axially downward from the top face and laterally adjacent to the pocket. The shaft is partially open to the pocket. A spring-loaded indicator is located in the shaft. The threaded fastener also includes a bimetallic strip located partially in the pocket and extending laterally into the shaft. The bimetallic strip has a movable end that axially restrains the spring-loaded indicator while a temperature of the nut is below a threshold temperature. The bimetallic strip, in response to the temperature exceeding the threshold temperature, laterally deflects the movable end to release the spring-loaded indicator. The component may be an axle nut, wheel hub, spacer, or hub cap.
1 . A device for a wheel-end system, comprising:
a component of the wheel-end system that defines a rotation axis and forms (i) a pocket extending axially downward from a top face of the component and (ii) a shaft extending axially downward from the top face and laterally adjacent to the pocket, the shaft being partially open to the pocket;
a spring-loaded indicator located at least partially in the shaft; and
a bimetallic strip located partially in the pocket and extending laterally into the shaft, the bimetallic strip having a movable end that axially restrains the spring-loaded indicator while a temperature of the component is below a threshold temperature;
wherein the bimetallic strip, in response to the temperature exceeding the threshold temperature, laterally deflects the movable end to release the spring-loaded indicator.
2 . The device of claim 1 , wherein the component is one of an axle nut, a hub cap, a spacer, a wheel hub, and a center cap.
3 . The device of claim 1 , the bimetallic strip including:
a fixed end, opposite the movable end, that is anchored in the pocket; and
a middle section, located between the fixed and movable ends, that is shaped as a coil.
4 . The device of claim 1 , the spring-loaded indicator including a pin that at least partially protrudes above the top face when the spring-loaded indicator is released.
5 . The device of claim 4 , the pin forming one or more notches that extend laterally inward from a side wall of the pin, each of the one or more notches being shaped such that the movable end, when located therein, axially restrains the pin.
6 . The device of claim 5 , wherein the one or more notches comprise a single notch that laterally circumscribes the pin.
7 . The device of claim 5 , further comprising an o-ring that laterally circumscribes the spring-loaded indicator and seals the shaft near the top face.
8 . The device of claim 7 , the pin forming an o-ring groove that laterally circumscribes the pin, the o-ring groove being sized to accept the o-ring.
9 . The device of claim 5 , the pin including:
a tapered section, located below the one or more notches, having a diameter that decreases with increasing axial distance from the one or more notches; and
a bottom flange located below the tapered section.
10 . The device of claim 5 , the spring-loaded indicator further including a spring located at least partially inside a blind hole that extends axially upward from a bottom face of the pin.
11 . The device of claim 4 , wherein the shaft is cylindrical and the pin is cylindrically symmetric.
12 . The device of claim 1 , further comprising a cover plate that covers the pocket.
13 . The device of claim 1 , wherein:
the movable end is a first movable end of the bimetallic strip;
the bimetallic strip further includes a second movable end opposite to the first movable end;
the first and second movable ends axially restrain the spring-loaded indicator from opposing lateral sides while the temperature of the component is below the threshold temperature; and
the bimetallic strip, in response to the temperature exceeding the threshold temperature, laterally deflects the first and second movable ends in opposite lateral directions to release the spring-loaded indicator.
14 . The device of claim 13 , wherein:
the bimetallic strip includes a curved section that is located between the first and second movable ends; and
the component includes a boss that is located in the pocket and forms a curved channel with a side wall of the pocket, the curved channel having a geometry to accept the curved section.
15 . The device of claim 14 , the boss being integrally formed with the component.
16 . The device of claim 14 , the boss forming a threaded fastener hole that extends axially downward from a top face of the boss.
17 . The device of claim 16 , the threaded fastener hole being sized to receive a screw that affixes a cover plate over the pocket.
18 . The device of claim 13 , wherein:
the bimetallic strip includes a curved section that is located between the first and second movable ends; and
the component forms a threaded fastener hole that extends axially downward from a bottom face of the pocket, the threaded fastener hole being located such that when a screw is inserted into the threaded fastener hole, the curved section partially encircles a shank of the screw.
19 . The device of claim 18 , further comprising a cover plate that covers the pocket, the cover plate forming a fastener through-hole such that when the cover plate is positioned over the pocket, the fastener through-hole is laterally aligned with the threaded fastener hole.
20 . A device for a wheel-end system, comprising:
a component of the wheel-end system that defines a rotation axis and forms a pocket extending axially downward from a top face of the component;
an indicator located in the pocket; and
temperature-sensitive material located in the pocket and axially covering the indicator;
wherein the temperature-sensitive material, in response to reaching a threshold temperature, changes to a liquid that flows out of the pocket to visibly reveal the indicator.
21 . The device of claim 20 , wherein the component is one of an axle nut, a hub cap, a spacer, a wheel hub, and a center cap.
22 . The device of claim 20 , the indicator being located near a bottom face of the pocket.
23 . The device of claim 20 , the component further forming one or more sprues that extend axially downward from a bottom face of the pocket.
24 . The device of claim 23 , each of the one or more sprues being shaped as a frustrum with top and bottom bases, the top base being located axially closer to the bottom face of the pocket than the bottom base, the top base having a smaller area than the bottom base.
25 . The device of claim 24 , wherein each of the one or more sprues is shaped as a right circular conical frustrum.
26 . The device of claim 23 , wherein the temperature-sensitive material fills at least part of each of the one or more sprues.
27 . The device of claim 21 , wherein the temperature-sensitive material is one of an alloy and a high-temperature polymer.
28 . A device for a wheel-end system, comprising:
a component of the wheel-end system that defines a rotation axis and forms a shaft extending axially downward from a top face of the component;
a spring-loaded indicator located in the shaft; and
temperature-sensitive material located in the shaft to axially restrain the spring-loaded indicator;
wherein the temperature-sensitive material, in response to reaching a threshold temperature, softens or changes to a liquid to release the spring-loaded indicator.
29 . The device of claim 28 , wherein the component is one of an axle nut, a hub cap, a spacer, a wheel hub, and a center cap.
30 . The device of claim 28 , wherein:
the component forms a lip where the shaft meets the top face;
the shaft is shaped as a cylinder with a shaft diameter; and
the lip is shaped as a cylinder with a lip diameter that that is less than the shaft diameter.
31 . The device of claim 30 , the spring-loaded indicator including:
a pin with (i) a body whose diameter is less than the lip diameter and (ii) a base whose diameter is greater than the lip diameter; and
a spring that axially pushes the base against the lip when the spring-loaded indicator is released.
32 . The device of claim 30 , wherein the temperature-sensitive material is shaped as a disc that the spring-loaded indicator axially pushes against the lip.
33 . The device of claim 28 , the spring-loaded indicator including a pin that at least partially protrudes above the top face when the spring-loaded indicator is released.
34 . The device of claim 28 , wherein the temperature-sensitive material is one of an alloy and a high-temperature polymer.