A seal assembly includes an outer annular case disposed within and coupled with a rotatable outer member to be angularly displace about a central axis. An annular flexible seal is disposed within and coupled with the case to angularly displace about the central axis when the outer member rotates about the axis. The flexible seal has elastomeric sealing lip(s) engageable with an outer circumferential surface of the shaft or of a sleeve disposed about the shaft. An annular inner rigid seal is disposed within the outer case and has an inner end coupled with the shaft or the sleeve, the flexible seal being radially displaceable with respect to the inner rigid seal. An outer annular rigid seal is disposed about the inner seal and has an inner end sealing against the inner rigid seal. A biasing member biases the outer rigid seal against the inner rigid seal.

A seal comprising: an annular body defining an inner sidewall and an outer sidewall extending from a base; and a plurality of energizing elements disposed within a recess between the inner and outer sidewalls, wherein at least two adjacent energizing elements of the plurality of energizing elements have different unit loads as compared to one another, and wherein the at least two adjacent energizing elements contact the inner sidewall.

A seal comprising: an annular body defining an inner sidewall and an outer sidewall extending from a base; and a plurality of energizing elements disposed within a recess between the inner and outer sidewalls, wherein at least two adjacent energizing elements of the plurality of energizing elements have different unit loads as compared to one another, and wherein the at least two adjacent energizing elements contact the inner sidewall.

A sealing arrangement for an electric machine, which is between a first part attached to a rotatable shaft and a second part immobile with respect to a stator of the electric machine includes a plurality of zig-zag sections of a channel of a labyrinth seal in a radial direction of the electric machine. The channel of the labyrinth seal includes a second seal which is fixedly attached to the first part and which has an elastic material part, the second seal is pressed in the radial direction against a surface of the second part, a normal of which has a component parallel to the radial direction, at rotational speeds a centrifugal force of which to the second seal is weaker than a spring force of the second seal, and the second seal opening a gap between the second seal and said surface at rotational speeds the centrifugal force of which to the second seal is greater than the spring force of the second seal.

A sealing arrangement for an electric machine, which is between a first part attached to a rotatable shaft and a second part immobile with respect to a stator of the electric machine includes a plurality of zig-zag sections of a channel of a labyrinth seal in a radial direction of the electric machine. The channel of the labyrinth seal includes a second seal which is fixedly attached to the first part and which has an elastic material part, the second seal is pressed in the radial direction against a surface of the second part, a normal of which has a component parallel to the radial direction, at rotational speeds a centrifugal force of which to the second seal is weaker than a spring force of the second seal, and the second seal opening a gap between the second seal and said surface at rotational speeds the centrifugal force of which to the second seal is greater than the spring force of the second seal.

Spring energized seal assemblies each with one or two sealing elements and a canted coil spring located in a spring cavity of the sealing element or of the two sealing elements to bias an inner flange and an outer flange of the respective spring cavity away from one another. The canted coil springs can have un-conventional coil shapes with one or more straight coil segments and/or with curved connecting ends. The coils can have dimples to provide multiple biasing points. The coils can have loops. The canted coil springs with un-conventional coil shapes can be used to improve spring loading on a sealing element.

Spring energized seal assemblies each with one or two sealing elements and a canted coil spring located in a spring cavity of the sealing element or of the two sealing elements to bias an inner flange and an outer flange of the respective spring cavity away from one another. The canted coil springs can have un-conventional coil shapes with one or more straight coil segments and/or with curved connecting ends. The coils can have dimples to provide multiple biasing points. The coils can have loops. The canted coil springs with un-conventional coil shapes can be used to improve spring loading on a sealing element.

A sealing system includes: a first seal including at least one first seal lip sealing against a first surface and a second surface and having a first cavity filled with a first energizer forcing the at least one first seal lip against the first surface and the second surface, the first cavity facing a first pressure region; and a second seal spaced from the first seal and having at least one second seal lip sealing against the first surface and the second surface, the second seal including a second cavity filled with a second energizer forcing the at least one second seal lip against the first surface and the second surface to separate a second pressure region from a third pressure region. The at least one second seal lip is configured to deform such that fluid pressures in the first, second, and third pressure regions equalize.

A sealing system includes: a first seal including at least one first seal lip sealing against a first surface and a second surface and having a first cavity filled with a first energizer forcing the at least one first seal lip against the first surface and the second surface, the first cavity facing a first pressure region; and a second seal spaced from the first seal and having at least one second seal lip sealing against the first surface and the second surface, the second seal including a second cavity filled with a second energizer forcing the at least one second seal lip against the first surface and the second surface to separate a second pressure region from a third pressure region. The at least one second seal lip is configured to deform such that fluid pressures in the first, second, and third pressure regions equalize.

A powered fastener driver includes a housing, a cylinder supported by the housing, and a moveable piston positioned within and moveable along a driving axis of the cylinder. The piston includes a circumferential groove on an outer peripheral surface thereof. A driver blade is attached to the piston and moveable therewith between a top-dead-center (TDC) position and a driven or bottom-dead-center (BDC) position. A seal assembly is received in the circumferential groove. The seal assembly is configured to create a seal between the piston and the cylinder. The seal assembly includes a biasing member and a seal member positioned radially outwardly of the biasing member relative to the driving axis.