In some aspects, the techniques described herein relate to a refrigerant compressor, including: a stator; a rotor configured to rotate with respect to the stator; and at least one step seal between the rotor and the stator, wherein the step seal includes a first tooth and a second tooth extending from the rotor toward the stator, wherein a downstream surface of the first tooth and an upstream surface of the second tooth are arranged at an angle relative to one another, wherein the angle is less than 90°.

A seal arrangement is disclosed for sealing an interior space between a bearing housing and a rotatable shaft with respect to a surrounding area. The seal arrangement includes a seal body which can be fastened to the bearing housing with a first end and a second end. The seal body is extended in an elongate manner along a main extent direction and is configured to be arranged in an annular manner around the rotatable shaft in a mounted state. The first end and the second end have a common butt joint. A projecting region is arranged at the first end of the seal body and projects tangentially with respect to the rotatable shaft in the direction of a predefined main rotational direction of the rotatable shaft. The projecting region projects beyond the seal body and overlaps the butt joint.

An apparatus for sealing such a gap may be a plunger seal which may include a flap arm comprising resilient sheets and a wall arm comprising resilient sheets. A proximal end portion of the flap arm may include a closeout seal coupled to the flap. A proximal end portion of the wall arm may include a plunger having a geometry corresponding to that of the closeout seal so the plunger may be matingly received by the closeout seal. When positioned in a gap, the plunger seal may exert a force to urge the flap arm towards the flap and to urge the wall arm and resilient sheet towards the structure to seal the gap.

Apparatuses are provided herein useful to sealing a gap between a movable flap and a stationary structure, such as a gap between a gas turbine engine nozzle flap and a corresponding sidewall. An apparatus for sealing such a gap may be a dynamic skirted leaf seal which may include a flap arm, a wall arm opposite the flap arm, and a support arm disposed between the flap and wall arms. A distal end portion of the flap arm may comprise a first skirt and a distal end portion of the support arm may comprise a second skirt that engages the first skirt. When positioned in a gap, the skirted leaf seal may exert a force to urge the first flap arm towards the flap and to urge the wall arm and the support arm towards the structure to seal the gap.

A blower unit, particularly for an apparatus for assisting respiration, comprises a housing (2), an impeller (1) accommodated in an impeller chamber (3) in the housing (2), and a motor (12), connected to the impeller (1) via a shaft (15), which is accommodated in a motor chamber (13) in the housing (2). The motor (12) is fixed between walls (14, 18) of the motor chamber (13) by means of buffers, with at least one of the buffers being a sealing ring (16) which separates the shaft (15) from a passage for cooling air (33) which, in radial section, extends annularly around the motor (12).

A seal device is configured so that seal properties can be held over a long period of time. A seal device 1 inserted into and disposed between grooves each formed at first and second components which are adjacent to each other and collectively form a housing structure includes a first seal member inserted into the groove of the first component, a second seal member inserted into the groove of the second component, and a partitioning member extending between the first and second seal members to partition a space between the grooves of the first and second components and arranged movably relative to the first and second seal members.

A sealing fin fixing apparatus can fix a sealing fin to a rotor in a shortened period of time to minimize variations of the pullout strength of the sealing fin. In the sealing fin fixing apparatus that fixes the sealing fin in a sealing groove defined in the outer circumference of the rotor of a rotary machine and includes a headstock for setting a rotor thereon, a Z-stage movable along a Z-axis, an X-stage movable along an X-axis, a tool rest supported on the X-stage, and a caulking tool mounted on the tool rest and including a shank and a pressing roller, while the pressing roller is being held against a caulking wire inserted, together with the sealing fin, in the sealing groove in the rotor that is set on the headstock, the headstock is actuated to rotate the rotor, thereby caulking the caulking wire to fix the sealing fin to the rotor.

An article comprises a first portion comprising a first alloy and a second portion comprising a second alloy that is metallurgically bonded to the first portion to form a monolithic article. The metallurgical bonding involves the application of an electrical current across the bond line and results in a retention of a metallurgical structure of the first portion and of a metallurgical structure of the second portion immediately adjacent to a bond line. The first portion has a first dominant property and the second portion has a second dominant property. The first dominant property is different from the second dominant property. The first dominant property is selected to handle operating conditions at a first position of the article where the first portion is located and the second dominant property is selected to handle operating conditions at a second position of the article where the second portion is located.

A hybrid electric propulsion system including: a gas turbine engine comprising a low speed spool and a high speed spool, the low speed spool comprising a low pressure compressor and a low pressure turbine, and the high speed spool comprising a high pressure compressor and a high pressure turbine; an electric motor configured to augment rotational power of the high speed spool or the low speed spool; at least one blade outer air seal positioned between an outer case of the high pressure turbine and a plurality of blades of the high pressure turbine; a clearance control system operably coupled to the at least one blade outer air seal, the clearance control system configured to vary a position of the at least one blade outer air seal with respect to the plurality of blades of the high pressure turbine; and a controller operably coupled to the electric motor and the clearance control system, wherein the controller is configured to operate the clearance control system based upon an operational state of the electric motor.

A seal for sealing a gap in a combustion arrangement of a gas turbine. The seal is formed by a L-shaped angle profile and a clamping profile. Both profiles have on the opposite side an engagement flank for fastening in a sealing groove and a sealing flank bearing against one another. The clamping profile further includes a holding portion, which is located opposite the associated sealing flank and also bears against the sealing flank of the angle profile, and a clamping portion connecting the sealing flank to the holding portion.