Freudenberg-Nok General Partnership

Freudenberg-Nok Gp

John C Dahlheimer

Kevin F Ice

Robert S Holt

Robert E Doucette

A radial shaft seal is provided for accommodating large radial offset of the shaft relative to a housing. The seal includes an annular retainer insert provided for engaging the seal to a fixed housing. An annular elastomeric seal body is molded to the retainer insert and includes a flexible axially extending portion extending from an inner surface of the retainer insert. A seal portion extends from a radially inward end of the flexible portion and includes first and second seal lips and an elastomeric bearing surface disposed between the first and second sealing lips. The bearing surface includes a plurality of raised pads adapted to engage the shaft. The pads each include a rounded edge on lateral sides thereof for encouraging the creation of a lubricating film between the pads and shaft. The pads are lubricated by a lubricant disposed in a lubricant chamber disposed between the first and second seal lips.

Prelubricated multi-lipped radial shaft seal with large radial offset accommodation

A radial shaft seal is provided for accommodating large radial offset of the shaft relative to a housing. The seal includes an annular retainer insert provided for engaging the seal to a fixed housing. An annular elastomeric seal body is molded to the retainer insert and includes flexible axially extending portion extending from an inner surface of the retainer insert. A seal portion extends axially from a radially inward end of the radially inwardly extending portion and includes a seal lip with a garter spring disposed radially outward of the sealing lip and an elastomeric bearing surface disposed adjacent to the sealing lip. The bearing surface includes a plurality of raised pads adapted to engage the shaft. The pads each include a rounded edge on lateral sides thereof for encouraging the creation of a lubricating film between the pads and shaft. The pads are lubricated by direct exposure to the fluid being sealed.

Radial shaft seal with large radial offset accommodation

A unitized seal assembly is provided for installation between linkages of a chain drive designed for tracked vehicles. The seal assembly facilitates field preventative maintenance on the drive chain by utilizing an integral spacer that holds the critical sealing surfaces together at all times, and has a seal head that can be easily removed from the outer link bore of a chain link. Removal of the seal head from the outer link bore causes as-installed clearance passageways between the seal head and seat portions and the spacer to forcefully close and prevent abrasive particles from getting inside the seal and reaching the interior interface junction of the dynamic sealing surfaces during seal maintenance. The seal assembly also includes additional sealing features that provide improved performance.

Unitized seal with integral spacer

A seal assembly includes a ring component for coupling a seat component to a shaft. The ring component includes a first portion having an annular shape and configured to have a sealed engagement with the shaft. The ring component also includes a second portion having a flange extending radially outwardly therefrom. The ring component is configured to receive the seat component between the flange and the first portion and thus form a seal seat assembly. The flange is configured to mechanically lock the seat component relative to the ring component when the seal seat assembly is disposed on the shaft.

Seal seat ring component with locking and venting features

A face seal is provided with a constriction ring around a rubber boot that constricts the normal outward bulging of the flex section of the rubber boot as it folds and tries to roll forward over itself during axial deflection. The constriction caused by the constriction ring provides for increased frictional hysteresis during compression and decompression of the boot flex section. This increased hysteresis increases the dampening capacity of the seal design and, therefore, reduces undesired vibrations and seal noise generation.

Face seal with constriction ring

A mechanical face seal, for sealing about a rotating shaft, includes a seal head assembly in sealing engagement with a seal seat assembly. The seal seat assembly has a washer with a portion that is sandwiched between a grommet and a seal seat. Another portion of the washer is sandwiched between a sleeve or shoulder on the shaft and an impeller. Frictional heat generated by the seal can be conducted away from the seal seat to the sleeve or shoulder on the shaft, which is particularly advantageous when the face seal is operated without water adjacent to the seal seat.

Heat conducting seal

A seal seat assembly utilizes a positive mechanical drive between a seal seat and the bore of a pump component, which in turn is mounted to and driven by the shaft by means of a positive mechanical engagement therebetween. The grommet accommodates the positive mechanical drive between the seal seat and the pump component. The seal assembly enables a robust, easily assembled three-component sub-assembly of the seal seat, grommet and pump component that can be handled as a single unit, and which easily installs onto, seals with, and becomes rotationally locked to a shaft. The positive engagement features, retaining features and static sealing features are axially aligned to provide an axially-compact seal assembly.

Seal seat assembly with specialized features

A seal assembly including a rotatable seal head subassembly also includes a fan that rotates with the seal head assembly, with the fan drawing air through a pump housing for purposes of cooling.

Fan cooled seal seat

A water pump includes a first enclosure having a center portion that is moveable from a normal condition to a deflected condition and a second enclosure adjacent to the first to form an internal cavity. An impeller is disposed within the internal cavity. A tubular shaft portion extends from the impeller through a bore in the second enclosure. The tubular shaft portion is press fit to a motor shaft which rotates the impeller within the internal cavity. As the motor shaft is inserted into the tubular portion of the impeller, a tool is used to press on and axially deflect the center portion of the first enclosure. Thus, the center portion of the first enclosure contacts the impeller and provides an opposing force on the impeller while the motor shaft is inserted into the tubular portion of the impeller. When the motor shaft is press-fit sufficiently into the tubular portion, the tool is removed. When the tool is removed, a convoluted portion around a center portion of the first enclosure biases the center portion to move axially away from the impeller and form a clearance gap between the impeller and the first enclosure. Several optional friction engagement members may be used to connect the motor shaft to the tubular shaft.

Deflectable enclosure cover

A seal head assembly includes a case. A ferrule is seated against the case. A spring is seated at one end against the ferrule. A spring seat receives a second end of the spring. The retainer ring has a band and a plurality of tabs, wherein the band engages the spring seat. A metal bellows has a first end in contact with the case and a second end having a contact surface for the tabs of the retainer ring. A seal washer has an annular groove, wherein the seal washer is received in the second end of the metal bellows. A seal is received in the annular groove of the seal washer.

Bellows face seal assembly

A water pump with a plurality of elastomeric blades on a rigid impeller is disclosed. The impeller has a tubular extension with a pair of flats on the outer diameter of the extension. The seal seat has a corresponding pair of flats on its inner diameter to engage the flats on the tubular extension for positive rotation. The impeller also has a retaining lip formed on its inner diameter and a sealing shoulder to form a retaining cavity along the tubular extension. The retaining lip receives the seal seat in the cavity by stretching the lip radially into a gap to accommodate the outer diameter of the seal seat. This stretch to fit feature eliminates the need to control the outer diameter of the seal ring to precise dimensions. The lip forms a static seal with the outer diameter of the seal seat. The elastomeric shoulder provides a static seal against the seal seat.

Elastomeric pump impeller

A mechanical face seal for use in a pump. The mechanical face seal including a seal head assembly, a seal seat assembly opposite and in contact with the seal head assembly. The seal head assembly including a gimbal ring engaging a first and second pair of gimbal pads. The first pair of gimbal pads is integral with an impeller insert and the second pair of gimbal pads is integral with a seal washer. The gimbal ring will continually adjust to misalignments of the pump and the seal components when hydraulic forces overcome the spring load of the seal head assembly and clamps the gimbal ring between the two pair of gimbal pads.

Gimballed mechanical face seal

A unitized seal impeller thrust system includes an impeller unit which includes a tubular neck portion that has flat surfaces on opposite sides of one another. The impeller unit includes a plurality of radially extending blades and a circular trough surrounding the neck portion. The system further includes a seal head assembly which is secured within the trough, and a seal seat assembly which engages the seal head assembly. The system further includes a thrust washer which engages the seal seat assembly and the retainer ring which is secured to the tubular neck portion at an end of the neck portion. The retainer ring also engages the thrust washer in a ball and socket type arrangement. The system provides a unitized seal, impeller, thrust system that is capable of preload testing and/or leak testing before assembly of the pump unit.

Unitized seal impeller thrust system

A regenerative turbine pump cover including an essentially flat bottom surface which includes a plurality of corner post projections. The post projections are located near comers of the cover. The bottom of the cover includes a central cutwater member having fillets extending from the sides and a raised circular projection radius extending from the top of the cutwater. The top of the cover includes well receptacles.

Regenerative turbine pump cover

An improved seal assembly utilizing a cup gasket having a flange portion secured or sandwiched between side surface of a mating ring and an inner surface of a radially extending side portion of an inner sleeve such that a static seal occurs in an axial direction. The seal further including a gap between an inner circumferential surface of the mating ring and the outer circumferential surface of the inner sleeve to detect any leakage past the static seal. Such a seal assures a long-term sealed mounting of the mating ring regardless of elastomer compressions set, shrinkage, or thermal contraction.

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Laconia, NH, United States of America

John C Dahlheimer