| 摘要 |
762,286. Making bearings ; forging. GLACIER METAL CO., Ltd. Jan. 7, 1955 [Jan. 19, 1954], No. 1649/54. Classes 83 (2) and 83 (4). A method of making a plain bearing halfliner 8 comprises pressing a blank between an inner die 9 having end walls 12 to engage the arcuate end faces 14 of the blank and an outer die 1 provided with an abutment 6 parallel to the rotary axis of the bearing to engage one edge or joint face 7 of the blank, the dies having co-operating semi-cylindrical die surfaces 3, 10 and being first moved bodily towards one another and then relatively rotated in a direction such that the blank is circumferentially compressed towards the abutment 6 whilst the axial length of the liner is limited by the end walls 12. The outer die 1 is recessed to form semi-cylindrical control surfaces 4 coaxial with and on either side of the die surface 3 and has a vertical slot 26 leading to a recess 25 which co-operates with a projection 28 on the inner die to form a locating lug 24 on the liner. The inner die has a step 15 to engage the liner joint face 16, a plain surface 17 to co-operate with a plain surface 18 on the outer die to limit the relative rotational movement'between the dies and semicylindrical flanges 11 forming the end walls 12 and adapted to engage in the recesses formed in the outer die by the surfaces 4. The upper,part 19 of the inner die is formed as a part cylindrical surface centred about an axis 20 offset from the axis of the surface 10 in a direction away from the abutment 6 and co-operating with a concave surface on a thrust-block 21 transversely slidably connected to a ram 23 and pivotally connected to die 9 by a pair of arms 22. In operation, a roughly semicylindrical blank is placed on the outer die surface 3 and the inner die is moved downwards by ram 23 until the flanges 11 contact the surfaces 4 after which, due to the offset of axis 20, the inner die is rotated about the axis of surface 10 through a small angle, e.g. between 3 and 5 degrees, towards the abutment 6, the blank being compressed between step 15 and abutment 6 whilst being axial restrained by the walls 12, thus controlling the thickness of the resulting liner. In an alternative method, the peripheral length of the liner is controlled by making the flanges 11 undersize so that they do not contact the surfaces 4 and rotating the inner die until the surfaces 17 and 18 engage. In both methods the axial length is controlled by the walls 12 and the lug 24 is formed by the projection 28 engaging in recess 25. In a modification, Fig. 10, the ram 31 and the inner die 9 are connected through a collapsible link system formed by a link 32 pivotally connected to the ram and an arm 30 rigidly secured to the inner die, the free ends of the arm 30 and the link 32 being pivotally connected together to a further link 33 connected to a fluid controlled piston 35 slidable in a cylinder 36. In operation, the fluid connection to the cylinder is closed and as the ram moves downwards the link system is rigid. When the die contacts the blank further downward movement is opposed causing an increase in fluid pressure in cylinder 36 until, at a predetermined value, a relief valve operates and the link system collapses, causing the arm 30 to pivot about the die surface and rotate the die whilst still pressing downwardly. To release the inner die the fluid pressure is released whilst the ram is descending, thus causing the die to pivot about the rounded edge of surface 17 and lift away from the finished liner. The blanks may be of a single metal or alloy, or of two or more superimposed layers of different metals or alloys bonded to one another. Specifications 409,289 and 722,276 are referred to. |
