Rapid movement loader slot bearing suitable for use on munitions deployment structures
A loader slot bearing includes an annular housing having first and second axial surfaces and an interior area extending therebetween. The interior area has a first inner surface that extends between the first and second axial surfaces. A portion of the inner surface is a first bearing surface that has a spherical contour. A slot extends partially into the first inner surface from the first axial surface. The slot has a first width. The annular housing is manufactured from a precipitation hardened corrosion resistant stainless steel. The loader slot bearing includes a truncated ball that is positioned in the slot and rotated so that the truncated ball is rotatably retained by the first bearing surface. The truncated ball is angularly misalignable relative to the housing and is manufactured from a 440C stainless steel. A dry lubricant is applied to the spherical exterior surface of the truncated ball.
1. A loader slot bearing comprising:
an annular housing having a first axial surface, a second axial surface and an interior area extending between the first axial surface and the second axial surface, the interior area being defined by a first inner surface that extends between the first axial surface and the second axial surface, a portion of the inner surface being a first bearing surface having a spherical contour and has a first surface hardness of 28 to 37 Rockwell C for dampening impact loads received by the slot loader bearing, a slot extending partially into the first inner surface from the first axial surface, the slot having a first width, and the annular housing being manufactured from a precipitation hardened corrosion resistant stainless steel;
a truncated ball having a spherical exterior surface extending a second width between a third axial surface and a fourth axial surface, the second width being less than the first width, the truncated ball being positioned in the slot and rotated so that the truncated ball is rotatably retained by the first bearing surface, the truncated ball being angularly misalignable relative to the housing, the truncated ball being manufactured from a 440C stainless steel per AMS 5630, wherein the spherical exterior surface of the truncated ball has a second surface hardness of 55 to 62 Rockwell C; and
a dry lubricant applied to the spherical exterior surface to facilitate direct sliding engagement of the spherical exterior surface with the first bearing surface,
wherein the housing and the truncated ball are configured to move relative to one another and withstand accelerations or impact loads during mechanism deployment of up to 4G.
2. The loader slot bearing of claim 1 , wherein the precipitation hardened corrosion resistant stainless steel is 17-4PH stainless steel pursuant to AMS 5643.
3. The loader slot bearing of claim 2 , wherein the 17-4PH stainless steel is in a condition H1150 heat treatment.
4. The loader slot bearing of claim 1 , wherein the precipitation hardened corrosion resistant stainless steel is 15-5PH stainless steel pursuant to AMS5659.
5. The loader slot bearing of claim 1 , wherein the truncated ball has a cylindrical bore extending between the third axial surface and the fourth axial surface, the bore being defined by a second inner surface; and
a pin having a cylindrical exterior surface, the pin extending through the cylindrical bore and the truncated ball being axially rotatable relative to the pin when frictional forces between the second inner surface and the cylindrical exterior surface is below a threshold level; and
wherein when the frictional forces exceed the threshold level, the pin and truncated ball lock together and are axially rotatable together, relative to the housing.
6. The loader slot bearing of claim 5 , wherein the pin is solid.
7. The loader slot bearing of claim 5 , wherein the cylindrical exterior surface defines a first outside diameter and the bore of the truncated ball has a first inside diameter that is at least 0.0001 to 0.0019 inches greater than the first outside diameter.
8. The loader slot bearing of claim 1 , wherein the dry lubricant comprises a molybdenum disulfide material in a binder.
9. The loader slot bearing of claim 1 , wherein the dry lubricant is of a maximum thickness of 0.0005 inches.
10. The loader slot bearing of claim 1 , wherein the spherical exterior surface of the truncated ball is defined by a second outside diameter, the housing defines a third width between the first axial surface and the second axial surface and wherein a ratio of the third width to the second outside diameter is about 0.35 to 0.50.
11. The loader slot bearing of claim 1 , further comprising a shaft extending from and integral with the annular housing thereby forming a rod end.
12. The loader slot bearing of claim 11 , wherein the shaft is integral with a support frame or is secured to the support frame with at least one fastener.
13. The loader slot bearing of claim 1 , wherein the truncated ball is manufactured from a bar stock or cast form of the precipitation hardened corrosion resistant stainless steel.
14. The loader slot bearing of claim 1 , wherein the truncated ball is dropped in or forced fit in to the interior area of the housing.
15. The loader slot bearing of claim 1 , wherein the truncated ball is dropped in to the interior area of the housing through a slot milled or broached all the way through the housing.
16. A loader slot bearing comprising:
an annular housing having a first axial surface, a second axial surface and an interior area extending between the first axial surface and the second axial surface, the interior area being defined by a first inner surface that extends between the first axial surface and the second axial surface, a portion of the inner surface being a first bearing surface having a spherical contour and has a first surface hardness of 28 to 37 Rockwell C for dampening impact loads received by the slot loader bearing, a slot extending partially into the first inner surface from the first axial surface, the slot having a first width, and the annular housing being manufactured from a precipitation hardened corrosion resistant stainless steel;
a truncated ball having a spherical exterior surface extending a second width between a third axial surface and a fourth axial surface and the truncated ball having a cylindrical bore extending between the third axial surface and the fourth axial surface, the second width being less than the first width, the bore being defined by a second inner surface, the truncated ball being positioned in the slot and rotated so that the truncated ball is rotatably retained by the first bearing surface, the truncated ball being angularly misalignable relative to the housing and the truncated ball being manufactured from a 440C stainless steel per AMS 5630, wherein the spherical exterior surface of the truncated ball has a second surface hardness of 55 to 62 Rockwell C;
a dry lubricant applied to the spherical exterior surface to facilitate direct sliding engagement of the spherical exterior surface with the first bearing surface; and
a pin having a cylindrical exterior surface, the pin extending through the cylindrical bore and the truncated ball being axially rotatable relative to the pin when frictional forces between the second inner surface and the cylindrical exterior surface is below a threshold level,
wherein when the frictional forces exceed the threshold level, the pin and truncated ball lock together and are axially rotatable together, relative to the housing.
17. The loader slot bearing of claim 16 , wherein the pin is solid.
18. The loader slot bearing of claim 16 , wherein the cylindrical exterior surface defines a first outside diameter and the bore of the truncated ball has a first inside diameter that is at least 0.0001 to 0.0019 inches greater than the first outside diameter.