Self-lubricating plain bearing

Claim 2

A self-lubricating plain bearing for a shaft, comprising a bore for receiving the shaft; a porous member which is arranged in the bore at an inner portion thereof and which occupies only a part of the bore in the axial direction thereof, the porous member being adapted to be impregnated with lubricant and surround the shaft at a clearance therefrom; and a bearing surface means adapted to support the shaft, which is disposed in the bore adjacent to the porous member and which extends outwardly therefrom, the bearing surface means having a bearing clearance from the shaft therein, the clearance between the shaft and the porous member being larger than the bearing clearance between the shaft and the bearing surface means, and the pore size of the porous member being larger than said clearance between the shaft and the porous member, whereby lubricant in the porous member flows by capillary action out of the clearance between the porous member and the shaft into the bearing clearance between the shaft and the bearing surface means.

Claim 3

A bearing as set forth in claim 1 wherein the capillary flow suction action applied to the lubricant to cause it to flow into said bearing clearance is adapted to the relationship S 12 >S 13 >S 3 , wherein S 12 is the suction capability of the bearing clearance between the shaft and the bearing surface means, S 13 is the suction capability of said clearance between the shaft and the porous member, and S 3 is the suction capability of the porous member.

Claim 4

A bearing as set forth in claim 1 wherein the porous member is a sintered member formed by sintering material in a loosely mixed condition without the application of additional pressure.

Claim 5

A bearing as set forth in claim 3 wherein said starting material of the sintered member comprises spheroidal particles.

Claim 6

A bearing as set forth in claim 1 wherein said clearance between the shaft and the porous member is from about 0.096 to 0.201 mm.

Claim 7

A bearing as set forth in claim 1 wherein said bearing clearance between the shaft and the bearing surface means is in a range of from about 0.021 to 0.039 mm.

Claim 8

A bearing as set forth in claim 1 wherein the porous member comprises spheroidal sintered bronze.

Claim 9

A bearing as set forth in claim 7 wherein the grain size of said porous member material is from 0.5 to 0.71 mm.

Claim 10

A bearing as set forth in claim 1 wherein the porous member is impregnated with a lubricant in the form of an oil having a viscosity of 62 cST/8.2E.

Claim 11

A self-lubricating plain bearing for a shaft, comprising a body having a bore therein for receiving an end portion of said shaft, a bearing sleeve means disposed within the bore for supporting the shaft and having a bearing clearance therefrom, and a porous, lubrication-impregnated member which is disposed in the bore at the end of said bearing sleeve means and which is closer towards said shaft end portion, the porous member having a clearance from said shaft which is greater than said bearing clearance, and the bore size of the porous member being larger than said clearance between the shaft and the porous member, whereby said clearance between said shaft and said porous member is adapted to draw lubricant from said porous member and said bearing clearance is adapted to draw lubricant from said clearance to cause lubricant to flow by capillary action to the co-operating bearing surfaces of said shaft and said bearing sleeve means.

Claim 12

A self-lubricating plain bearing for a shaft, comprising a body having a bore therein for receiving an end portion of said shaft, a bearing sleeve means disposed within the bore for supporting the shaft and having a bearing clearance therefrom, and a porous, lubrication-impregnated member which is disposed in the bore at the end of said bearing sleeve means and which is closer towards said shaft end portion, the porous member having a clearance from said shaft which is greater than said bearing clearance, and the bore size of the porous member being larger than said clearance between the shaft and the porous member, whereby said clearance between said shaft and said porous member is adapted to draw lubricant from said porous member and said bearing clearance is adapted to draw lubricant from said clearance to cause lubricant to flow by capillary action to the co-operating bearing surfaces of said shaft and said bearing sleeve means.

Claim 13

A bearing as set forth in claim 10 wherein said porous member comprises spheroidal sintered bronze.

Claim 14

A bearing as set forth in claim 10 wherein the porous member is impregnated with a lubricant in the form of an oil having a viscosity of 62 cST/8.2E.

Claim 15

In a device comprising a shaft and a member carried by said shaft and adapted to be rotated therewith, a self-lubricating bearing comprising: a support means defining a bore receiving a portion of said shaft; a lubricant-impregnated porous member which is arranged in the bore at an inner portion thereof and which occupies only a part of the bore in the axial direction thereof, and which surrounds the shaft at a clearance therefrom; and a bearing surface means adapted to support the shaft, which is disposed in the bore adjacent to the porous member and which extends outwardly therefrom, the bearing surface means having a bearing clearance from the shaft therein, the clearance between the shaft and the porous member being larger than the bearing clearance between the shaft and the bearing surface means, and the pore size of the porous member being larger than said clearance between the shaft and the porous member, whereby lubricant in the porous member flows by capillary action out of the clearance between the porous member and the shaft into the bearing clearance between the shaft and the bearing surface means.

Claim 16

In a device comprising a shaft and a member carried by said shaft and adapted to be rotated therewith, a self-lubricating bearing comprising: a support means defining a bore receiving a portion of said shaft; a lubricant-impregnated porous member which is arranged in the bore at an inner portion thereof and which occupies only a part of the bore in the axial direction thereof, and which surrounds the shaft at a clearance therefrom; and a bearing surface means adapted to support the shaft, which is disposed in the bore adjacent to the porous member and which extends outwardly therefrom, the bearing surface means having a bearing clearance from the shaft therein, the clearance between the shaft and the porous member being larger than the bearing clearance between the shaft and the bearing surface means, and the pore size of the porous member being larger than said clearance between the shaft and the porous member, whereby lubricant in the porous member flows by capillary action out of the clearance between the porous member and the shaft into the bearing clearance between the shaft and the bearing surface means.