Method for manufacturing pre-loaded double-row rolling bearing unit
AssigneeNsk Ltd.
InventorSeizo Miyazaki
Life of this patent
Estimating the term…
Abstract
The preload of the double row rolling bearing unit after completion is kept at a proper value regardless of the elastic deformation of the shaft caused when pushing the inner race in the axial direction wherein the balls are first installed in the bearing at the first pitch P1 of the ball rows which is larger than the pitch p1 in the state where the preload is proper and then preloaded to a pitch slightly smaller than the second pitch p1, so that the ball rows have the second pitch p1 after the shaft is elastically restored.
Claims11
A method for manufacturing a pre-loaded double-row rolling bearing unit comprising components including a first member having a first peripheral surface formed with a first raceway, a second member being concentric to the first member and having a second peripheral surface that faces the first peripheral surface to be formed with a second raceway facing the first raceway and with a third raceway separated in the axial direction from the second raceway, a third member fitted under a sufficient fitting strength around the first member and at a fitting depth with respect to said first member, supported to be concentric with the first and second members and having a third peripheral surface facing the second peripheral surface to be formed with a fourth raceway facing the third raceway, and a plurality of balls located in double-rows between the first and second raceways and between the third and fourth raceways, wherein a proper pre-load is applied to the respective balls by adjusting the fitting depth of the third member with respect to the first member, and the third member is pushed in the axial direction with respect to the first member to obtain the fitting depth in a length required for the proper pre-load, the method comprising the steps of calculating or measuring a movement resistance force that occurs due to the fit between the first and third members and that resists the pushing movement of the third member in the axial direction, calculating an amount of elastic deformation of the components based on the movement resistance force, and stopping the work of press-fitting the third member when the third member has been moved with respect to the first member in the direction of increasing the pre-load, by a compensation value in length that corresponds to the amount of elastic deformation, further from the position which corresponds to the length required for the proper pre-load.
A method for manufacturing a pre-loaded double-row rolling bearing unit comprising components including a first member having a first peripheral surface formed with a first raceway, a second member being concentric to the first member and having a second peripheral surface that faces the first peripheral surface to be formed with a second raceway facing the first raceway and with a third raceway separated in the axial direction from the second raceway, a third member fitted under a sufficient fitting strength around the first member and at a fitting depth with respect to said first member, supported to be concentric with the first and second members and having a third peripheral surface facing the second peripheral surface to be formed with a fourth raceway facing the third raceway, and a plurality of balls located in double-rows between the first and second raceways and between the third and fourth raceways, wherein a proper pre-load is applied to the respective balls by adjusting the fitting depth of the third member with respect to the first member, and the third member is pushed with a pushing force in the axial direction with respect to the first member to obtain the fitting depth in a length required for the proper pre-load, the method comprising the steps of removing or reducing the pushing force on the third member before the third member reaches an axial position with respect to the first member that corresponds to a length required for application of the proper pre-load, so that the space between the first raceway and the fourth raceways increases due to the elastic restoration force of the components, and measuring the amount in change of the pre-loaded that is the amount in change in the space between the first and fourth raceways before and after the pushing force is removed or reduced, obtaining a relationship of the amount in change in pre-load due to the elastic deformation of the components based on the measured amount in change in pre-load and the amount of change in the pushing force to calculate a compensation value in length, and the work of press-fitting of the third member is completed when the third member is moved with respect to the first member in the direction of increasing the pre-load, by an amount equal to the compensation value in length, further from the position which corresponds to the required length for the proper pre-load.
Dependencies are inferred from the claim text.