Bladed rotors

Claim 2

A bladed rotor including a hub casing defined by two casing parts, each having a first portion including radially-outwardlydirected projections, the two portions being of substantially identical form so that when said parts are held together in assembled relation by securing means said projections form radially-outwardly-directed sockets of circular cross-section in which the blades of the rotor are mounted with freedom for pitchchange adjustment about their longitudinal axes, the plane in which the said two parts are in engagement being disposed diametrically of all the sockets, each of said casing parts also having a single cylindrical portion projecting from its said first portion, the two cylindrical portions being of substantially identical form and extending from the first portions away from each other with their axes coincident with the axis of rotation of the rotor, space-defining means which separate the two cylindrical portions, the one axially from the other, one end closure wall provided at the end of one of said cylindrical portions remote from said plane, another end closure wall positioned at that end of the other of said cylindrical portions remote from said plane, a piston comprising a hollow rod, which is disposed with one end portion thereof in slidable engagement with respect to the inner wall of said one cylindrical portion, and a piston head formed by an end wall which closes the other end portion of the hollow rod and which is disposed in slidable engagement with respect to the inner wall of said other cylindrical portion, and means provided in said space which connect the piston to the blades, said other cylindrical portion and its end closure wall forming a chamber for said piston into which fluid is suppliable under pressure for effecting axial sliding movement of the piston with respect to the cylindrical portion and thus adjustment of the blades about their longitudinal axes.

Claim 3

A bladed rotor including a hub casing defined by two casing parts, each having a first portion including radially-outwardly-directed projections, the two portions being of substantially identical form so that when said parts are held together in assembled relation by securing means said projections form radially-outwardly-direction sockets of circular cross-section in which the blades of the rotor are mounted with freedom for pitch-change adjustment about their longitudinal axes, the plane in which the said two parts are in engagement being disposed diametrically of all the sockets, each of said parts also having a single cylindrical portion projecting from its said first portion, the two cylindrical portions being of substantially identical form and extending from the first portions away from each other with their axes coincident with the axis of rotation of the rotor, space-defining means which separate the two cylindrical portions, the one axially from the other, one end closure wall provided at that end of one of said cylindrical portions remote from said plane, another end closure wall positioned at that end of the other of said cylindrical portions remote from said plane, a piston comprising a hollow rod, whic is disposed with one end portion thereof in slidable engagement with respect to the inner wall of said one cylindrical portion, and a piston head formed by an end wall which closes the other end portion of the hollow rod and which is disposed in slidable engagement with respect to the inner wall of said other cylindrical portion, mechanical spring means, whose axis is coincident with said axis of rotation, which means at one end engages said one end closure wall and which so projects into said hollow rod as at its other end to engage said end wall forming said piston head, and means provided in said space which connect the piston to the blades, said other cylindrical portion and its end closure wall forming a chamber for said piston into which fluid is suppliable under pressure for effecting axial sliding movement of the piston against said spring means and thus adjustment of the blades about their longitudinal axes.

Claim 4

A bladed rotor including a hub casing defined by two casing parts, each having a first portion including radially-outwardly-directed projections, the two portions being of substantially identical form so that when said parts are held together in assembled relation by securing means said projections form radially-outwardly-direction sockets of circular cross-section in which the blades of the rotor are mounted with freedom for pitch-change adjustment about their longitudinal axes, the plane in which the said two parts are in engagement being disposed diametrically of all the sockets, each of said parts also having a single cylindrical portion projecting from its said first portion, the two cylindrical portions being of substantially identical form and extending from the first portions away from each other with their axes coincident with the axis of rotation of the rotor, space-defining means which separate the two cylindrical portions, the one axially from the other, one end closure wall provided at that end of one of said cylindrical portions remote from said plane, another end closure wall positioned at that end of the other of said cylindrical portions remote from said plane, a piston comprising a hollow rod, whic is disposed with one end portion thereof in slidable engagement with respect to the inner wall of said one cylindrical portion, and a piston head formed by an end wall which closes the other end portion of the hollow rod and which is disposed in slidable engagement with respect to the inner wall of said other cylindrical portion, mechanical spring means, whose axis is coincident with said axis of rotation, which means at one end engages said one end closure wall and which so projects into said hollow rod as at its other end to engage said end wall forming said piston head, and means provided in said space which connect the piston to the blades, said other cylindrical portion and its end closure wall forming a chamber for said piston into which fluid is suppliable under pressure for effecting axial sliding movement of the piston against said spring means and thus adjustment of the blades about their longitudinal axes.

Claim 5

A bladed rotor including a hub casing defined by two casing parts, each having a first portion including radially-outwardly-directed projections, the two portions being of substantially identical form so that when said parts are held together in assembled relation by securing means said projections form radially-outwardly-directed sockets of circular cross-section in which the blades of the rotor are mounted with freedom for pitch-change adjustment about their longitudinal axes, the plane in which the said two parts are in engagement being disposed diametrically of all the sockets, each of said casing parts also having a single cylindrical portion projecting from its said first portion, the two cylindrical portions being of substantially identical form and extending from the first portions away from each other with their axes coincident with the axis of rotation of the rotor, space-defining means which separate the two cylindrical portions, the one axially from the other, one end closure wall provided at that end of one of said cylindrical portions remote from said plane, another end closure wall positioned at that end of the other of said cylindrical portions remote from said plane, a piston comprising a hollow rod, which is disposed with one end portion thereof in slidable engagement with respect to the inner wall of said one cylindrical portion, and a piston head formed by an end wall which closes the other end portion of the hollow rod and which is disposed in slidable engagement with respect to the inner wall of said other cylindrical portion, means provided in said space which connect the piston to the blades, and said piston and said cylindrical portions being dimensioned to afford a range of sliding movement of the piston corresponding to a range of movement of the blades which includes positive and negative pitch, a first mechanical spring means and a second mechanical spring means the axes of which are coincident with said axis of rotation, said first spring means at one end engaging said end wall forming said piston head and at the other end engaging said second spring means, and said second spring means at its end remote from the first spring means engaging said one end closure wall, and said other cylindrical portion and its end closure wall forming a chamber for said piston into which fluid is suppliable under pressure for effecting axial movement of the piston against said spring means and thus adjustment of the blades.

Claim 6

A bladed rotor including a hub casing defined by two casing parts, each having a first portion including radially-outwardly-directed projections, the two portions being of substantially identical form so that when said parts are held together in assembled relation by securing means said projections form radially-outwardly-directed sockets of circular cross-section in which the blades of the rotor are mounted with freedom for pitch-change adjustment about their longitudinal axes, the plane in which the said two parts are in engagement being disposed diametrically of all the sockets, each of said casing parts also having a single cylindrical portion projecting from its said first portion, the two cylindrical portions being of substantially identical form and extending from the first portions away from each other with their axes coincident with the axis of rotation of the rotor, space-defining means which separate the two cylindrical portions, the one axially from the other, one end closure wall provided at that end of one of said cylindrical portions remote from said plane, another end closure wall positioned at that end of the other of said cylindrical portions remote from said plane, a piston comprising a hollow rod, which is disposed with one end portion thereof in slidable engagement with respect to the inner wall of said one cylindrical portion, and a piston head formed by an end wall which closes the other end portion of the hollow rod and which is disposed in slidable engagement with respect to the inner wall of said other cylindrical portion, means provided in said space which connect the piston to the blades, and said piston and said cylindrical portions being dimensioned to afford a range of sliding movement of the piston corresponding to a range of movement of the blades which includes positive and negative pitch, a first mechanical spring means and a second mechanical spring means the axes of which are coincident with said axis of rotation, said first spring means at one end engaging said end wall forming said piston head and at the other end engaging said second spring means, and said second spring means at its end remote from the first spring means engaging said one end closure wall, and said other cylindrical portion and its end closure wall forming a chamber for said piston into which fluid is suppliable under pressure for effecting axial movement of the piston against said spring means and thus adjustment of the blades.

Claim 7

A bladed rotor including a hub defined by two casing parts having portions which, when the parts are held together in assembled relation by securing means, form radially-outwardly-directed sockets of circular cross-section which house anti-friction bearing means by way of which the blades of the rotor are mounted with freedome for pitch-change adjustment about their longitudinal axes, the plane in which said two parts are in engagement being disposed diametrically of all the sockets, and said two parts each having a respective bore portion provided with an end closure wall remote from said plane, the axis of one bore portion being coincident with that of the other bore portion, space-defining means which separate said bore portions axially one with respect to the other, a hollow piston wholly enclosed within said two assembled casing parts with one end portion thereof slidably supported in said one bore portion and the other end portion thereof slidably supported in said other bore portion, said piston closed at said other end portion and there forming with said other bore portion an expansible pitch-change motor chmber which is connectible with fluid under pressure, means provided in said space which connect the piston to the blades whereby sliding movement of the piston with respect to the bore portions under the pressure of fluid in said chamber effects adjustment of said blades, a mechanical coil spring so extending within said hollow piston as at one end to engage the closed end portion thereof, and a Belleville washer stack which at one end is engaged by the other end of said coil spring and which, at its other end, engages the end closure wall of said one bore portion, said stack being engageable by said piston and compressible thereby as the piSton moves through part of its range of movement, and both said coil spring and said stack being arranged with their axes coincident with the rotational axis of the rotor.

Claim 8

A bladed rotor including a hub defined by two casing parts having portions which, when the parts are held together in assembled relation by securing means, form radially-outwardly-directed sockets of circular cross-section which house anti-friction bearing means by way of which the blades of the rotor are mounted with freedome for pitch-change adjustment about their longitudinal axes, the plane in which said two parts are in engagement being disposed diametrically of all the sockets, and said two parts each having a respective bore portion provided with an end closure wall remote from said plane, the axis of one bore portion being coincident with that of the other bore portion, space-defining means which separate said bore portions axially one with respect to the other, a hollow piston wholly enclosed within said two assembled casing parts with one end portion thereof slidably supported in said one bore portion and the other end portion thereof slidably supported in said other bore portion, said piston closed at said other end portion and there forming with said other bore portion an expansible pitch-change motor chmber which is connectible with fluid under pressure, means provided in said space which connect the piston to the blades whereby sliding movement of the piston with respect to the bore portions under the pressure of fluid in said chamber effects adjustment of said blades, a mechanical coil spring so extending within said hollow piston as at one end to engage the closed end portion thereof, and a Belleville washer stack which at one end is engaged by the other end of said coil spring and which, at its other end, engages the end closure wall of said one bore portion, said stack being engageable by said piston and compressible thereby as the piSton moves through part of its range of movement, and both said coil spring and said stack being arranged with their axes coincident with the rotational axis of the rotor.

Claim 9

A bladed rotor including a hub defined by two casing parts having portions which, when the parts are held together in assembled relation by securing means, form radially-outwardly-directed sockets of circular cross-section which house anti-friction bearing means by way of which the blades of the rotor are mounted with freedom for pitch-change adjustment about their longitudinal axes, the plane in which said two parts are in engagement being disposed diametrically of all the sockets, and said two parts each having a respective bore portion, the axis of one bore portion being co-incident with that of the other bore portion, space-defining means which separate said bore portions axially one with respect to the other, a hollow piston wholly enclosed within said two assembled casing parts with one end portion thereof slidably supported in said one bore portion and the other end portion thereof slidably supported in said other bore portion, said piston being closed at said other end portion and there forming with said other bore portion an expansible pitch-chnge motor chamber which is connectible with fluid under pressure, and the piston having surfaces spaced apart from the adjacent end faces of the roots of at least certain of the blades with portions upstanding from those surfaces which have such sliding relationship with said faces and which are so disposed in relation to the respective blade longitudinal axis, as substantially to prevent angular displacement of said piston about the rotational axis of the rotor with respect to said hub, the area of the face associated with each upstanding portion which is in engagement with the respective blade root end face being small in relation to the area of that root end face, spring means disposed between said piston and an abutment of said one bore portion, and means provided in said space which connect the piston to the blades whereby sliding movement of the piston with respect to the bore portions under the pressure of fluid in said chamber and against the effort of said spring means effects adjustment of said blades.

Claim 10

A bladed rotor including a hub defined by two casing parts having portions which, when the parts are held together in assembled relation by securing means, form radially-outwardly-directed sockets of circular cross-section which house anti-friction bearing means by way of which the blades of the rotor are mounted with freedom for pitch-change adjustment about their longitudinal axes, the plane in which said two parts are in engagement being disposed diametrically of all the sockets, and said two parts each having a respective bore portion, the axis of one bore portion being co-incident with that of the other bore portion, space-defining means which separate said bore portions axially one with respect to the other, a hollow piston wholly enclosed within said two assembled casing parts with one end portion thereof slidably supported in said one bore portion and the other end portion thereof slidably supported in said other bore portion, said piston being closed at said other end portion and there forming with said other bore portion an expansible pitch-chnge motor chamber which is connectible with fluid under pressure, and the piston having surfaces spaced apart from the adjacent end faces of the roots of at least certain of the blades with portions upstanding from those surfaces which have such sliding relationship with said faces and which are so disposed in relation to the respective blade longitudinal axis, as substantially to prevent angular displacement of said piston about the rotational axis of the rotor with respect to said hub, the area of the face associated with each upstanding portion which is in engagement with the respective blade root end face being small in relation to the area of that root end face, spring means disposed between said piston and an abutment of said one bore portion, and means provided in said space which connect the piston to the blades whereby sliding movement of the piston with respect to the bore portions under the pressure of fluid in said chamber and against the effort of said spring means effects adjustment of said blades.

Claim 11

A bladed rotor as claimed in claim 3, wherein said first spring means comprises a coil spring and the second spring means comprises a stack of spring washers, the external diameter of said stack being substantially greater than that of said coil spring.

Claim 12

A bladed rotor as claimed in claim 4, wherein a ported tube is connected to said piston and provides means by way of which fluid under pressure is introduced into said chamber for effecting movement of the piston against the effort of said coil spring and stack in the direction corresponding to adjustment of the blades in the pitch fining direction.

Claim 13

A bladed rotor as claimed in claim 4, wherein said casing parts include stop means with which the piston is co-operable and which afford the piston an extent of movement corresponding to movement of the blades in the positive pitch range and the negative pitch range, movement from the positive pitch range to the negative pitch range, and vice versa, being through zero pitch, and said stack being engaged by said piston only when the blades are in the negative pitch range.

Claim 14

A rotor as claimed in claim 1, wherein said securing means include bolts provided in the vicinity of the sockets.

Claim 15

A rotor as claimed in claim 2, wherein each blade is mounted in an anti-friction bearing provided in its socket, each said bearing being split in a diametral plane thereof.