Rotation-independent actuation of a machine element
View Patent ↗The invention relates to rotating machine element that contains a mechanism actuated by a fluid pressure. The aim of the invention is to allow for a supply of actuation fluid also during the rotation. To this end, a non-rotating control element ( 2 ) is mounted on two fluid bearings ( 3 ) on the machine element, said bearings being spaced apart in the axial direction and allowing flows of actuation fluid to flow from one element to the other. Feed lines (R, S) in the control element are provided with a series of radially inwards facing ports ( 13, 14 ) and reception channels ( 17, 18 ) in the machine element, a series of radially outward facing orifices ( 15, 16 ) being disposed in such a manner that in every relative position both elements for every individual flow of actuation fluid are disposed such that at least one port ( 13, 14 ) is aligned with one associated orifice ( 15, 16 ).
1. Actuating device for at least one fluid-operated mechanism located in a rotary part of a machine, with a non-rotating command ring journalled on said rotary machine part and comprising at least one delivery channel for providing an actuating fluid to at least one corresponding receiving channel located in the rotary machine part and leading to the mechanism, wherein that at least one outer bearing surface belonging to the command ring is journalled through the carrier fluid of a fluid bearing on at least one inner bearing surface belonging to the machine part, and in that the stream of actuating fluid flowing between the delivery and the receiving channel traverses an annular gap maintained by the carrier fluid between the machine part and the command ring characterized in that at least one delivery channel has several delivery orifices separated by a certain angle around the axis of the fluid bearing.
2. Actuating device according to claim 1 , characterized in that the command ring comprises at least one feeder channel for feeding carrier fluid to the fluid bearing, which feeder channel ends in at least two peripheral rows of outlets arranged on the outer surface of the fluid bearing.
3. Actuating device according to claim 2 , characterized in that the feeder channel ends in at least two peripheral rows of outlets, where the vectors of the flow at the outlets of both rows have different components in the axial direction of the fluid bearing.
4. Actuating device according to claim 3 , characterized in that the feeder channel ends in a pair of rows with inwardly oriented outlets, and in a pair of rows where paired outlets are oriented in axially opposed directions.
5. Actuating device according to claim 1 , characterized in that the command ring comprises at least two delivery channels, where the first one has two pairs of delivery orifices shifted by 180° and mutually offset in axial direction of the fluid bearing, whilst the second has orifices which are also shifted by 180° and which are axially positioned between the mutually offset orifices of the first delivery channel and angularly shifted by a certain amount with respect to these.
6. Actuating device according to claim 1 , characterized in that at least one delivery channel ends in delivery orifices which positioned in axial direction of the fluid bearing between the two peripheral rows of outlets.
7. Actuating device according to claim 1 , characterized in that the rotary machine part comprises at least one receiving conduit for transmitting the pressure of the actuating fluid to the mechanism that must be operated, and in that the receiving conduit has a row of peripheral receiving mouths, at least one of which is aligned in all positions of the rotary machine part with at least one delivery orifice of a corresponding delivery channel.
8. Actuating device according to claim 7 , characterized in that the receiving mouths of a receiving conduit are separated by equal angular distances and at that at least one delivery orifice of the corresponding delivery channel is shaped as an elongated slit the length of which is at least equal to the distance between two successive receiving mouths plus the smallest transversal extent of a receiving mouth.
9. Actuating device according to any of claims 6 to 8 , characterized in that when viewed in axial direction of the fluid bearing there is provided between a peripheral row of outlets and a delivery orifice at least one peripheral groove in the inner bearing surface, which groove is aligned with at least one mouth of at least one venting duct provided in the command ring and leading into the open atmosphere.
10. Actuating device according to claim 1 , characterized in that the rotary machine part comprises at least two receiving conduits with return valves near their input ends, where the return valve of each receiving conduit is forcibly opened when the pressure in one other exceeds a certain value.
11. Actuating device according to claim 1 , characterized in that the machine part is a front-end chuck, and the mechanism a device a pneumatically operated device for opening and closing said chuck.
12. Actuating device according to claim 1 , characterized in that the command ring comprises several delivery channels for the actuating fluid, wherein the delivery orifices of the different channels in an axial direction of the fluid bearing are shifted with respect to one another.
13. Method for operating a mechanism located in a rotary machine part and actuated by fluid pressure, characterized in that two fluid bearings separate a non-rotating command device from the rotary machine part, and that a stream of actuating fluid crosses from one to the other between said two fluid bearings, characterized in that the crossing occurs between several radial orifices of delivery channels located in the command device and a row of radially oriented mouths of receiving conduits provided in the machine part, which are arranged such that whatever the relative position of the machine part and the command device, at least one orifice of each delivery channel overlaps at least partially with at least one mouth of a corresponding receiving conduit.
14. Method according to claim 13 , characterized in that the leakage of carrier fluid from the fluid bearings due to the pressure in the fluid bearings is used as a means for counteracting the inflow of dirt into the fluid bearings and the contamination of the actuating fluid with dirt.