Trw Limited

United States of America As Represented by the Secretary of the Air Force

Ramsey Corporation

Jon W Martin

Thomas J Engler

Xinhua He

James M Zamel

Leslye M Fraser

Richard A Griese

Robert S Betros

The present invention resides in a boot seal for use in sealing a joint. The joint comprises first and second relatively movable parts. The boot seal is configured in the form of a sleeve to extend between and around the vehicle relatively movable parts. The sleeve has a laminate wall which comprises at least two layers of thermoplastic elastomeric material which are bonded together. At least one of the layers is a stretch-toughenable polyester thermoplastic elastomer which has been diametrically stretched in an amount effective to increase the toughness of said one layer. The laminate wall has a percent elongation to rupture of at least 100, and a flexural modulus which is less than 100,000 psi. The laminate wall preferably has a puncture resistance of at least 50 Newtons/mm wall thickness.

Method of manufacturing a boot seal

An apparatus ( ) includes a tie rod ( ) for a vehicle steering system. The tie rod ( ) has an axis ( ), a first cylindrical portion ( ) with a first outer surface ( ) of a first diameter ( ), and a second cylindrical portion ( ) coaxial with the first cylindrical portion ( ). The second cylindrical portion ( ) has a second outer surface ( ) of a second diameter ( ) smaller than the first diameter ( ). The tie rod ( ) has a ring portion ( ) projecting radially from the second outer surface ( ) of the second cylindrical portion ( ). The ring portion ( ) has a third outer surface ( ) extending axially along the second cylindrical portion ( ). A boot seal ( ) encircles the second cylindrical portion ( ). The boot seal ( ) has a sealing surface ( ) in sealing contact with the third outer surface ( ) of the ring portion ( ). The sealing surface ( ) defines a groove ( ) in the boot seal ( ). The ring portion ( ) is located in the groove ( ).

Boot for a rack and pinion steering gear assembly

A fluid power steering gear ( ) comprises a housing ( ). A power steering fluid ( ) is disposed within the housing ( ). A seal ( ) contains the power steering fluid ( ) within said housing ( ). A member ( ) extends through the housing ( ) and the seal ( ). The member ( ) is movable relative to the housing ( ) and the seal ( ) in response to a change in the fluid pressure in the housing ( ). The power steering fluid ( ) comprises a base oil and a metal-free lubricant additive. The metal-free lubricant additive is soluble in the base oil and modifies the interfacial surface tension between the base oil and the member ( ) and the base oil and the seal ( ). The weight percent of the metal-free lubricant additive is about 0.1% to about 5.0%, by weight of the power steering fluid ( ).

Power steering fluid additive

Plastic sleeve and method of manufacturing the same

An apparatus (,) includes a bearing (,) linking first and second vehicle parts (,) for movement relative to each other, and a boot seal (,) protecting the bearing (,). The boot seal (,) is a tube of heat shrinkable thermoplastic material. The tube (,) has a first end portion (,) shrunken against the first vehicle part (,), a second end portion (,) shrunken against the second vehicle part (,), and a flexible intermediate portion (,) which is deflectable between the opposite end portions (,) upon movement of the vehicle parts (,) relative to each other.

Laminated tubular structure

Heat shrinkable boot seal and method of installation

An improved seal assembly (,) is used in a power steering system (,) having an axially reciprocatable shaft (,). The seal assembly (,) has an inner side (,) which is exposed to hydraulic fluid. The seal assembly (,) includes a flexible lip (,) having a circular line (,) of minimum diameter. An annular coil spring (,) is disposed in engagement with a side of the flexible lip opposite from the line (,) of minimum diameter. The coil spring (,) has a circular central axis (,) which is axially offset from a plane containing the line (,) of minimum diameter of the flexible lip (,). The circular central axis (,) of the coil spring (,) is offset from the line (,) of minimum diameter of the flexible lip (,) in a direction toward the inner side (,) of the seal assembly (,) prior to installation of the seal assembly in the power steering system (,).

Seal assembly

A fluid power vehicle steering gear (10) comprises a tubular housing (22), a fluid (34) disposed within the tubular housing, and a member (20) movable relative to the housing in response to a change in the fluid pressure in the housing. The fluid comprises a mixture of a base oil and a grease. The weight of the grease in the mixture is about 0.1% to about 5% of the weight of the base oil in the mixture.

Power steering fluid

A lightweight housing (12) for a hydraulic power steering gear (10) includes a tubular structure (34 or 68) with a longitudinal central axis (21 or 23). The tubular structure (34 or 68) has layers extending circumferentially around the axis (21 or 23), including an inner layer (100), an outer layer (102), and an intermediate layer (104) between the inner and outer layers (100 and 102). The inner layer (100) is formed of plastic material. An inner surface (118 or 120) of the inner layer (100) defines an outer boundary of a space (36,38 or 88) containing hydraulic fluid under pressure. The outer layer (102) is formed of metal material. The intermediate layer (104) is formed of elastomeric material, and is compressively loaded radially between the inner and outer layers (100 and 102).

Lightweight hydraulic power steering gear

A seal assembly (10) includes a relatively rigid seal holder (12) and a relatively soft O-ring seal member (14). The seal member (14) is disposed in an annular groove (16) in the seal holder (12). A plurality of ribs (70) are disposed between the seal member (14) and the bottom (76) of the annular groove (16) in the seal holder (14) to retard rotation of the seal member (14) relative to the seal holder (12). In one embodiment of the invention, the ribs (70) are integrally formed as one piece with the seal holder (12) and engage an outer side surface (72) of the seal member (14). In another embodiment of the invention, the ribs (70) are integrally formed as one piece with the seal member (14a) and engage a smooth arcuate bottom of an annular groove in a seal holder. In another embodiment of the invention, both the seal holder (12) and the seal member (14a) are provided with ribs (70 and 70a).

A hydraulic power rack and pinion steering assembly (10) includes a valve core (98) and a valve sleeve (100) which are supported for relative rotation. A damping ring assembly (150) is interposed between the valve core (98) and the valve sleeve (100) to reduce vibrations and thereby to attenuate noise. The damping ring assembly (150) includes an inner ring (160) press fit on the valve core (98) and an outer ring (170) press fit in the valve sleeve (100). An elastomeric member (180) is disposed in the annulus between the inner ring (160) and the outer ring (170). The elastomeric member is bonded to the inner ring (160). Ribs (200) on the outer ring (170) are received in grooves (240) in the elastomeric member (180). A small gap (260) between the elastomeric member (180) and the outer ring (170) enables initial relative movement between the outer ring (170) and the inner ring (160) before the elastomeric member (180) engages the ribs (200).

Power steering assembly

A hydraulic power rack and pinion steering assembly (10) includes a valve core (98) and a valve sleeve (100) which are supported for relative rotation. A damping ring assembly (150) is interposed between the valve parts (98, 100) to reduce vibrations and thereby to attenuate noise. The damping ring assembly (150) includes an inner ring (160) press fit on the valve core (98) and an outer ring (170) press fit in the valve sleeve (100). An elastomeric member (180) is disposed in the annulus between the inner ring (160) and the outer ring (170). The elastomeric member (180) is bonded to the inner ring (160). Ribs (210-216) on the inner ring (170) are received in grooves (270-276) in the elastomeric member (180). The ribs (210-216) sequentially engage the elastomeric member (180) upon incremental relative rotation between the valve parts (98, 100) to provide a damping effect which changes at an increasing rate as the valve parts move from the centered condition.

Power steering assembly with damping ring

A hydraulic power steering apparatus (10) comprises a rotatable input member (31), a rotatable output member (130), and a housing supporting (11) the input member (31) and the output member (130) for rotation about an axis (45) relative to each other. A hydraulic control valve assembly (30) in the housing (11) includes a valve core (40), a valve sleeve (41) and a plurality of hydraulic seals (120-126) which block leakage of hydraulic fluid from the valve assembly (30). The hydraulic power steering apparatus (10) further includes an elastomeric damping ring (200) extending circumferentially between the valve core (40) and the valve sleeve (41). The elastomeric damping ring (200) damps vibrations of the valve core (40) relative to the valve sleeve (41), and thereby attenuates noise in the apparatus (10).

Hydraulic power steering gear with noise attenuation

A hydraulic power rack and pinion steering gear (10) includes a valve housing (32) and a hydraulic ram (20). The steering gear (10) further includes a composite plastic supporting body (12) which contains both the valve housing (32) and the hydraulic ram (20). The composite plastic supporting body (12) is formed of a high temperature thermoplastic binder material which is reinforced with glass fibers.

Hydraulic power steering gear with composite plastic supporting body

A method of manufacturing a ring-shaped hydraulic seal (10) produces a cylindrical sealing surface (12) having portions (24) formed of a plastic material and portions (26) formed of an elastomeric material. The method includes the steps of forming a plastic ring (30) and molding an elastomeric material into a cavity (50) in the plastic ring (30). The cylindrical sealing surface (12) is formed by grinding away the material of the ring (30) to expose a surface (26) of the elastomeric material which is contained in the cavity (50) in the ring (30). The plastic portions (24) of the cylindrical sealing surface (12) are defined by the ground surface (82) of the plastic ring (30). The elastomeric portions (26) of the cylindrical sealing surface (12) are defined by the exposed surfaces (26) of the elastomeric material.

Growing community of inventors

Los Alamitos, CA, United States of America

Jon W Martin