Mechanical face seals
AssigneeJohn Crane UK Limited
InventorChristopher J. Watts
Life of this patent
Estimating the term…
Abstract
A mechanical face seal includes a seal face member which is secured in fixed rotational relationship and sealed with respect to one component by means of a resilient bellows unit, said bellows unit being attached at one end to the associated component and at the other end to the seal face member, the seal face member being biased into sealing engagement with a second seal face member by compression of the bellows unit, the bellows unit defining a plurality of convolutions, a convolution in a portion of the bellows unit subject to higher stressing having a pitch which is greater than and/or a depth which is less than that of a convolution in a portion of the bellows unit subject to lower stressing, thereby evening out the stress distribution in the bellows unit when in operation.
Claims15
A mechanical face seal including a seal face member which is secured in fixed rotational relationship and sealed with respect to one of a pair of relatively rotatable components by means of a resilient bellows unit, said bellows unit being attached at one end to the associated component and at the other end to the seal face member, the seal face member being biassed into sealing engagement with a second seal face member associated with the other component by compression of the bellows unit, the bellows unit defining a plurality of convolutions, each convolution having a pitch which is the axial separation between a point on one convolution and a corresponding point on the next convolution and a depth which is the radial separation between the extremity of the crown and the extremity of the root of the convolution, wherein at least one of the pitch and depth of the convolutions differs along the length of the bellows.
A mechanical face seal including a seal face member which is secured in fixed rotational relationship and sealed with respect to one of a pair of relatively rotatable components by means of a resilient bellows unit, said bellows unit being attached at one end to the associated component and at the other end to the seal face member, the seal face member being biassed into sealing engagement with a second seal face member associated with the other component by compression of the bellows unit, the bellows unit defining a plurality of convolutions, each convolution having a pitch which is the axial separation between a point on one convolution and a corresponding point on the next convolution and a depth which is the radial separation between the extremity of the crown and the extremity of the root of the convolution, wherein at least one of the pitch and depth of the convolutions differs along the length of the bellows and the depth of the convolutions is less in portions of the bellow unit subject to higher stressing than in portions of the bellows unit subject to lower stressing.
A mechanical face seal including a seal face member which is secured in fixed rotational relationship and sealed with respect to one of a pair of relatively rotatable components by means of a resilient bellows unit, said bellows unit being attached at one end to the associated component and at the other end to the seal face member, the seal face member being biased into sealing engagement with a second seal face member associated with the other component by compression of the bellows unit, the bellows unit defining a plurality of convolutions, each convolution having a pitch which is the axial separation between a point on one convolution and a corresponding point on the next convolution and a depth which is the radial separation between the extremity of the crown and the extremity of the root of the convolution, wherein at least one of the pitch and depth of the convolutions differs along the length of the bellows and variation in at least one of the pitch and depth of the convolutions is progressive from a portion of the bellows unit subject to higher stressing to a portion of the bellows unit subject to lower stressing.
Dependencies are inferred from the claim text.