摘要:
A fluid lubrication bearing apparatus which can stably produce high bearing performance is provided at low costs. Moreover, a method for producing a housing for hydrodynamic bearing apparatuses which can improve the accuracy of form of the housing of this type at low costs is provided.In forming a housing 7 which has a cylindrical shape and comprises a fixing face 7c for fixing the outer circumferential surface 8b of a bearing sleeve 8, and axial circulation grooves 7d for bringing both end faces 8c, Sd of the bearing sleeve 8 into circulation on the inner periphery by forging, a groove molding portion 18a2 is provided on the outer circumference of a rod 18 which serves as a forming mold for the inner periphery of the housing 7, and the circulation grooves 7d are formed by forging with this groove molding portion 18a2. Moreover, after a sealing face 107d and a cylindrical outer circumferential surface 107e provided on the outer periphery of the housing 107 are formed by forging, an inner circumferential surface 107c is formed by forging. Accordingly, the thrust bearing face 107a is finished to have the perpendicularity with respect to the inner circumferential surface 107c or outer circumferential surface 107e of 20 Mm or less. Moreover, the sealing face 107d is finished to have the coaxiality with respect to the inner circumferential surface 107c or outer circumferential surface 107e of 20 p.m or less. Moreover, the outer circumferential surface 107e is finished to have the coaxiality with respect to the inner circumferential surface 107c of 20 p.m or less.
摘要:
A fluid lubrication bearing apparatus which can stably produce high bearing performance is provided at low costs. Moreover, a method for producing a housing for hydrodynamic bearing apparatuses which can improve the accuracy of form of the housing of this type at low costs is provided.In forming a housing 7 which has a cylindrical shape and comprises a fixing face 7c for fixing the outer circumferential surface 8b of a bearing sleeve 8, and axial circulation grooves 7d for bringing both end faces 8c, 8d of the bearing sleeve 8 into circulation on the inner periphery by forging, a groove molding portion 18a2 is provided on the outer circumference of a rod 18 which serves as a forming mold for the inner periphery of the housing 7, and the circulation grooves 7d are formed by forging with this groove molding portion 18a2. Moreover, after a sealing face 107d and a cylindrical outer circumferential surface 107e provided on the outer periphery of the housing 107 are formed by forging, an inner circumferential surface 107c is formed by forging. Accordingly, the thrust bearing face 107a is finished to have the perpendicularity with respect to the inner circumferential surface 107c or outer circumferential surface 107e of 20 μm or less. Moreover, the sealing face 107d is finished to have the coaxiality with respect to the inner circumferential surface 107c or outer circumferential surface 107e of 20 μm or less. Moreover, the outer circumferential surface 107e is finished to have the coaxiality with respect to the inner circumferential surface 107c of 20 μm or less.
摘要:
A housing for a fluid lubrication bearing apparatus is produced. The housing has a cylindrical shape whose inner periphery having a fixing face to which an outer circumferential surface of a bearing sleeve is to be fixed. The method includes providing a forging mold having a groove molding portion extending parallel to a direction of a stroke of said mold and a face molding portion having a convex cylindrical shape on an outer periphery of the forging mold for forming the fixing face of the housing. The method further includes forming the housing with the forging mold, while forging circulation grooves and the fixing face simultaneously on the inner periphery of the housing with the groove molding portion and the face molding portion of the forging mold.
摘要:
A fluid bearing apparatus includes a housing 7 which has a cylindrical shape having a fixing face 7c for fixing the outer circumferential surface 8b of a bearing sleeve 8, and axial circulation grooves 7d for bringing both end faces 8c, 8d of the bearing sleeve 8 into circulation on the inner periphery by forging. A groove molding portion 18a2 is provided on the outer circumference of a rod 18 which serves as a forming mold for the inner periphery of the housing 7, and the circulation grooves 7d are formed by forging with this groove molding portion 18a2. Moreover, after a sealing face 107d and a cylindrical outer circumferential surface 107e provided on the outer periphery of the housing 107 are formed by forging, an inner circumferential surface 107c is formed by forging.
摘要:
A method for producing a housing for a hydrodynamic bearing apparatus includes forming a housing 7 which has a cylindrical shape and which includes a fixing face 7c for fixing the outer circumferential surface 8b of a bearing sleeve 8, and axial circulation grooves 7d for bringing both end faces 8c, 8d of the bearing sleeve 8 into circulation on the inner periphery. The method includes providing a groove molding portion 18a2 on the outer circumference of a rod 18 which serves as a forming mold for the inner periphery of the housing 7, and forming the circulation grooves 7d of the housing by forging with the groove molding portion 18a2 of the mold. Moreover, after a sealing face 107d and a cylindrical outer circumferential surface 107e provided on the outer periphery of the housing 107 are formed by forging, an inner circumferential surface 107c is formed by forging.
摘要:
A method for producing a housing for a hydrodynamic bearing apparatus includes forming a housing 7 which has a cylindrical shape and which includes a fixing face 7c for fixing the outer circumferential surface 8b of a bearing sleeve 8, and axial circulation grooves 7d for bringing both end faces 8c, 8d of the bearing sleeve 8 into circulation on the inner periphery. The method includes providing a groove molding portion 18a2 on the outer circumference of a rod 18 which serves as a forming mold for the inner periphery of the housing 7, and forming the circulation grooves 7d of the housing by forging with the groove molding portion 18a2 of the mold. Moreover, after a sealing face 107d and a cylindrical outer circumferential surface 107e provided on the outer periphery of the housing 107 are formed by forging, an inner circumferential surface 107c is formed by forging.
摘要:
A shaft member for hydrodynamic bearing apparatuses which can restore the pressure balance in a thrust bearing gap formed on both axial sides of the flange portion in an early stage is provided at low costs.A shaft material 10 integrally having a shaft portion 11 and a flange portion 12 is formed as a through-hole 19 opening to its both end faces 12a, 12b on the flange portion 12 of the shaft material 10 is formed in a common forging step. As a result, the through-hole 29 is formed to open to the inner diameter side of these bearing gap W1, W2 avoiding thrust bearing gaps W1, W2 formed on both end faces of the flange portion 22 of the shaft member 2 as a finished product.
摘要:
A low-cost shaft member for hydrodynamic bearing apparatuses restores the pressure balance in a thrust bearing gap formed on both axial sides of the flange portion in an early stage. A shaft material integrally having a shaft portion and a flange portion with a through-hole between both end faces of the flange portion is formed in a common forging step. As a result, the through-hole is formed to open to an inner diameter side of the bearing gaps avoiding the thrust bearing gaps formed on both end faces of the flange portion of the shaft member as a finished product.
摘要:
A shaft member for hydrodynamic bearing apparatuses which can restore the pressure balance in a thrust bearing gap formed on both axial sides of the flange portion in an early stage is provided at low costs.A shaft material 10 integrally having a shaft portion 11 and a flange portion 12 is formed as a through-hole 19 opening to its both end faces 12a, 12b on the flange portion 12 of the shaft material 10 is formed in a common forging step. As a result, the through-hole 29 is formed to open to the inner diameter side of these bearing gap W1, W2 avoiding thrust bearing gaps W1, W2 formed on both end faces of the flange portion 22 of the shaft member 2 as a finished product.
摘要:
A shaft member for hydrodynamic bearing apparatuses having higher dimensional accuracy produced at low costs and a method for producing the same are provided. Moreover, a shaft member for hydrodynamic bearing apparatuses having hydrodynamic grooves processed with high accuracy and a method for producing the same are provided without a large increase in the processing costs. A shaft material 10 integrally having a shaft portion 11 and a flange portion 12 is formed by a forging process, and the cylindricity of a part or the entire outer circumferential surface 11a of the shaft portion 11 is corrected. The end face 11b of the shaft portion of the shaft material 10 and the end face 12b of the flange portion 12 on the opposite side of the shaft portion are ground relative to the corrected face 13 mentioned above, and the outer circumferential surface 10b of the shaft material 10 is ground relative to these end faces 11b, 12b. This renders the cylindricity of the radial bearing faces 23a, 23b formed on the outer periphery of the shaft portion 21 of the produced shaft member 2 to be 3 μm or lower. Moreover, in a common forging step, a shaft material 110 integrally having the shaft portion 111 and flange portion 112 is formed, while simultaneously thrust hydrodynamic groove regions 112a, 112b are formed on both end faces of the flange portion 112. After the forging process, in a common rolling step, radial hydrodynamic groove regions 113a, 113b are formed on the outer circumferential surface 111a of the shaft portion 111. In a grinding step following the rolling process, the radial hydrodynamic groove regions 113a, 113b and the thrust hydrodynamic groove regions 112a, 112b are ground.