| 摘要 |
<p>A method for machining an angularly disposed array of parallel longitudinally extending slots in a bore of a component, the method comprising the steps of: gripping said component (1) in a gripping means of a workholding device (2) mounted to a workholding spindle (3) indexable about a first axis; cutting said array of slots in said bore by a series of progressively deeper cutting strokes of a cutting tool (5), said tool mounted to a cutting spindle (7) rotatable about a second axis (8) substantially at right angles to and offset from said first axis; and the cutting of each slot followed by indexation of said workholding spindle (3); and during the cutting of at least one of said slots, relative movement between the component (1) and second axis (8) takes place due to movement of the component (1) along the first axis or movement of the second axis in a direction substantially parallel to said first axis or both. A one piece sleeve (34) for a rotary valve (31), the sleeve (34) comprising an array of inlet (26) and return (27) slots formed in the bore of the sleeve, the inlet slots (26) being stopped short of the axial extremities of the bore, the return slots (27) extending to one extremity of the bore providing an exit area for return oil when the sleeve is installed in the rotary valve, characterised in that at least one said return slot is also extended to the other axial extremity of the sleeve bore providing an entry area (24) for leakage oil when the sleeve is installed in the rotary valve, the entry area (24) provided for leakage oil being substantially smaller than the exit area provided for return oil.</p> |
