Abstract: Various embodiments of the disclosure include a system having: a computing device configured to monitor a sealing oil from a dynamoelectric machine by performing actions including: establish a baseline flow rate for the sealing oil through the dynamoelectric machine for designed operating conditions; calculate a plurality of average flow rates for the sealing oil through the dynamoelectric machine from a set of measured flow rates in each of a plurality of successive designated periods; provide an alert suggesting action in response to at least one of the average flow rates deviating from a threshold flow rate, the threshold flow rate derived from the baseline flow rate to indicate a fault in the sealing oil; and calculate an expected sealing life for the sealing oil based upon a pattern in the plurality of average flow rates for the plurality of successive designated periods.

Abstract: Devices and methods useful for non-invasively measuring and indicating a rate of fluid flow are disclosed. In one embodiment, a sensor housing adapted to received fluid flow therethrough is provided. A radio frequency tag and a masking element can be disposed in the sensor housing. The masking element and the radio frequency tag can be configured to move relative to one another. The relative positions or movement can alter the response of the radio frequency tag to a wireless signal (which can be emitted from an external reading device, for example) and thereby indicate a rate of fluid flowing through the housing. For example, in some embodiments, the masking element can selectively cover at least part of the radio frequency tag in correspondence to the flow rate, which can change a characteristic of the radio frequency tag's response to the wireless signal.

Abstract: The invention relates to a pedal travel simulator for the hydraulic connection to a pressure chamber of a master brake cylinder of a hydraulic brake system, in particular for motor vehicles, having a housing and a simulator piston that is diplaceably mounted in the housing, wherein the simulator piston delimits a first hydraulic simulator chamber together with the housing, which simulator chamber can accommodate pressurizing media. Wherein an elastic restoring means acts on the simulator piston, wherein the pedal travel simulator includes a second hydraulic simulator chamber for accommodating pressurizing media, the simulator chamber being delimited by an elastically deformable membrane. The invention further relates to an actuating unit for a hydraulic motor vehicle brake system of the brake-by-wire type, and to a hydraulic motor vehicle brake system.

Abstract: A twin power valve assembly (10) for a hydraulic braking system having a single body (16) with twin power valve arrangements, each having a spool (36, 36?) with a longitudinally extending passageway (36D, 36D?) for providing a modulation of the pressure applied to the brakes, and an integral balance piston (60, 60?) contained within the body (10) that equalizes the pressure applied to the left and right hand brakes when both brakes are applied.

Abstract: In a brake system including a master cylinder and an electrically-driven hydraulic pressure generator with front and rear pistons, when the hydraulic pressure generator cannot be operated and a failure of a first hydraulic system linked to a rear fluid chamber of the generator occurs and makes a first hydraulic system open to the atmosphere, the brake-fluid pressure of a second hydraulic system transmitted from the master cylinder to a wheel cylinder via a front fluid chamber of the generator is used to perform braking. A forward-facing third front cup seal provided at an intermediate portion of the front piston prevents the brake-fluid pressure generated by the master cylinder from leaking out from a front supply port via the rear fluid chamber. At the same time, a stopper prevents the pressure of the front fluid chamber from moving the front piston excessively backward. The braking is accordingly secured by use of the second hydraulic system linked to the front fluid chamber of the motor cylinder.

Abstract: This invention relates to a hydropneumatic piston reservoir (1) with a primary cylinder (2) in which runs a separating piston (12) with free mobility, with the separating piston (12) sealed off circumferentially, with the separating piston (12) inside the primary cylinder (2) separating two pressure chambers (16, 18) from one another. The separating piston (12) has an axial separating piston rod (20) at one end that is sealed off circumferentially from the primary cylinder (2) and is guided as a plunger (22) in a connected secondary cylinder (4) and is subjected to or can be subjected to a pressure medium. The plunger (22) at its free end away from the primary cylinder (2) has a bumper element (24) with a bumper area (28) projecting radially over the outer circumference (26) of the plunger (22).

Abstract: A brake apply master cylinder includes a body and a piston assembly. The body includes a bore. The bore has a longitudinal axis, a closed front end, a primary fluid outlet fluidly connectable to a primary brake circuit, and a secondary fluid outlet fluidly connectable to a secondary brake circuit. The piston assembly includes a single brake apply piston positioned in the bore. The piston assembly fluidly divides the bore into a primary fluid chamber in fluid communication with the primary fluid outlet and a secondary fluid chamber in fluid communication with the secondary fluid outlet. Another brake apply master cylinder includes a body, a piston assembly, and a return spring assembly. The return spring assembly is positioned in the bore of the body and extends from the closed front end of the bore to a return-spring seat of a single brake apply piston of the piston assembly.

Abstract: A passive hydraulic controller is disclosed, in which the volumes V1 and V2 at the two sides of the piston of two or more hydraulic cylinders in each case are connected to one another hydraulically, so that a displacement of the piston in one of the cylinders results in a displacement of the piston in at least one of the other cylinders (follow-up control). The sum of all the piston travels ?s=k1s1+k2s2+ . . . +knsn in hydraulic controllers of said type should ideally always be ?s=0=const, with the proportionality factors k1; k2 . . . kn representing the reciprocal of the piston surfaces of the cylinder, and their signs being dependent on whether the connecting lines between the hydraulic cylinders are crossed or not. Passive hydraulic controllers of the generic type are, however, not positionally stable over time (?s?O?const), in particular under the action of static basic loads.

Abstract: A pressure pulse generator comprising a circuit (12) filled with a pressure fluid, and at least one communication channel (15) that is connected to the circuit and via which the pressure fluid can flow into and out of the circuit. The pressure pulse generator comprises a first pair (8, 9) and a second pair (10, 11) of electrically controlled valves that are connected in series, and the first pair of valves (8,9) is arranged in said circuit (12) upstream the at least one communication channel (15), and the second pair of valves (10, 11) is arranged in said circuit (12) downstream the at least one communication channel (15).

Abstract: An improved compensation piston arrangement for use with a dual circuit master cylinder having a single service piston for simultaneously pressurizing a first fluid chamber and a second fluid chamber, wherein the compensation piston arrangement provides for pressure balancing between the first fluid chamber and the second fluid chamber to compensate for minor normal differences between the first and second fluid chamber. The compensation piston arrangement includes a movable compensation piston slidably disposed within a bore of a compensation housing, wherein the housing defines a pair of end stops positioned on opposing sides of the compensation piston. The bore is in fluid communication with the fluid chambers such that the pressure within the first fluid chamber acts on a first side of the compensation piston, and the pressure within the second fluid chamber acts on a second end of the compensation piston which is opposite the first end.

Abstract: A brake system (10) having a proportioning device (18) through which a first fluid pressure is communicated to a first brake circuit and a second fluid pressure is communicated to a second brake circuit. The proportioning device (18) has a housing (90) with a first bore (204) connected with a first passage (98) for receiving the first fluid pressure and with a second passage (100) for receiving the second fluid pressure. A first piston (210) located in the first bore (204) of the housing (90) separates the first passage (98) from the second passage (100). The first piston (210) responds to a higher fluid pressure of the first and second fluid pressures by moving in the first bore (204) to providing additional fluid pressure to a lower fluid pressure of the first and second fluid pressures to substantially equalize the first and second fluid pressures supplied to the first and second brakes circuits for effecting said brake application.

Abstract: A hydro-pneumatic pressure booster is proposed in which the reservoir chamber is limited by an elastic partition wall instead of a sliding piston.

Abstract: An actuating unit for hydraulic automotive vehicle brake systems, including a vacuum brake power booster, a master brake cylinder, and an operating element, configured to achieve a reduction of overall axial length and a simultaneous reduction of the weight and a relief of the booster housing from forces of reaction. The brake pedal (3) operating arm is interposed between the vacuum brake power booster (1) and the master brake cylinder engaging an axially extending member interconnecting a control valve piston and a master cylinder piston (2). The booster housing (10) and fluid reservoir (4) are mounted within the engine compartment while the master cylinder housing has a flange portion fixed to the splashwall and a main portion which projects out of the engine compartment through the splash wall, and into the passenger compartment. The hydraulic reaction forces are absorbed directly from the master cylinder housing into the splashwall rather than through the booster housing.

Abstract: The present invention is directed to a mechanical hydraulic pressure dampening devices for use in a steering system of an articulated self-propelled work vehicle. The dampening devices are hydraulically positioned between the steering cylinders of the work vehicle and absorb hydraulic pressure spikes in the steering system. In the preferred embodiment, the pressure dampener comprises a pressure accumulator that is fluidly coupled to the steering cylinder by a shuttle check valve. The shuttle check valve shifts in response to a pressure spike so that it can be absorbed by the pressure accumulator. In a second embodiment, the pressure dampener comprises a cylinder having two pistons that are biased into a normal position by a spring extending between the pistons. Spaces are formed on either side of the pistons and are hydraulically coupled to the steering cylinders. A central space formed between the two pistons is hydraulically coupled to a sump return line.

Abstract: A tandem master cylinder with a booster used for a hydraulic actuator such as an automotive brake system. The master cylinder has a first and a second independently movable presser piston disposed in tandem in a first housing such that the presser pistons and the first housing define a first and a second pressure chamber. The booster has a first power piston advanced by a fluid pressure in a first power chamber formed in a second housing, to advance the first presser piston. The booster has a valve operable due to a relative movement between the first power piston, and an operating member for operating said booster, whereby the fluid pressure in the first power chamber is controlled according to an operating force applied to the operating member.

Abstract: A master cylinder includes a housing movably supporting a pair of pistons and carrying a fluid reservoir assembly. The fluid reservoir assembly carries a differential area piston and a float which cooperate to activate a single reed switch, thereby generating a warning signal for a vehicle operator.

Abstract: Modular proportioners such as those of U.S. Pat. No. 4,213,655 are machined and separated into parts provided with appropriate O-ring seals so that the proportioners may be installed in an auxiliary bore of the master cylinder body. Threaded proportioner connections are eliminated. The proportioner parts are assembled by dropping them in place, in order, in the bore. They are retained in place by a retaining ring. This eliminates threaded connections and is adapted for automatic assembly.

Abstract: A master cylinder having a fluid pressure control valve mechanism which is constituted by a cylinder body, pistons slidably received in the cylinder body for defining pressure chambers in cooperation with each other and with one end wall of the cylinder body, respectively, a fluid pressure supply chamber in communication with a reservoir and isolated from the pressure chambers, a fluid pressure passage extending between one of the pressure chambers and a brake cylinder and a fluid pressure control valve mechanism having an annular space in communication with the fluid pressure supply chamber and isolated from the one pressure chamber.

Abstract: A master cylinder for a vehicular brake includes a cylinder closed at one end and open at the other end, a sleeve slidably received within the cylinder, a piston assembly including a pair of pistons integrally connected together, a stop on the cylinder for confining the piston assembly within the cylinder, and a spring disposed between the sleeve and piston assembly for normally biasing one end of the sleeve against the closed end of the cylinder and the piston assembly against the stop. One of the pistons and the closed end of the cylinder define a first pressure chamber therebetween and the pistons define a second pressure chamber therebetween. In operation, the sleeve is moved towards one of the pistons in response to a difference in the amount of remaining oil between the two pressure chambers against the force of the spring.

Abstract: The tandem master cylinder is provided with an equalizer device comprising a plunger mounted intermediate two chambers which are respectively connected to the two cavities of the master cylinder. At least one of the ducts connecting the master cylinder and the equalizer device is formed with a constriction slowing down the flow of brake fluid so as to permit a pressure buildup in one of the braking circuits, in case of failure of the other circuit, since the very start of the pedal stroke.

Abstract: A master cylinder assembly for a vehicle braking system having two pressure circuits, comprises a master cylinder having two separate pressure chambers associated with respective pistons one chamber being arranged for connection to one of the pressure circuits, generally the circuit to the front wheel brakes, and a control valve arrangement fast with the master cylinder. The control valve arrangement has an inlet for connection to the other of the chambers and an outlet for connection to the other of the pressure circuits, usually the rear wheel brake circuit, a normally-open valve for controlling communication between the inlet and the outlet, and an auxiliary piston assembly movable to open and close the valve to control the pressure applied to the rear wheel brakes as compared to full braking pressure applied to the front wheel brakes.

Abstract: A tandem master cylinder device having a cylinder body slidably receiving therein a driving piston and a floating piston so as to define a first liquid chamber and a second liquid chamber, the device housing a liquid pressure control valve by which a differential in output liquid pressure between a front brake pressure and a rear brake pressure is produced. A stepped piston is mounted on the floating piston to open and close a poppet valve.

Abstract: In a known tandem master cylinder with two regulators for use in vehicles using diagonally split brake circuits, machining and assembly of the components is time consuming which makes the device expensive to manufacture. Moreover, the arrangement is only realizable with master cylinders having a relatively large diameter. There are also functional disadvantages, particularly that in the event of failure of a brake circuit the fluid volume consumption of the other brake circuit is materially increased which further increases the brake pedal travel. To eliminate these shortcomings, the tandem master cylinder with two regulators of the present invention includes means which, in the event of failure of a brake circuit, the regulator valve of the other brake circuit is actuated mechanically by one of the pressure pistons so that the regulator valve of the intact brake circuit is kept open to enable unreduced braking pressure to be coupled to the intact brake circuit.

Abstract: A master cylinder for a hydraulic brake system of an automotive vehicle having front and rear sets of brake cylinders is disclosed, in which during the application of brake pressure above a predetermined value at which modulation and reduction of the rate at which pressure is fed to the rear brake cylinders occurs, the rate at which pressure is fed to the front brake cylinder is increased as compared with the rate before the modulation point.

Abstract: A fluid pressure generator, such as a master cylinder, includes a housing with a bore for movably supporting a pair of pistons. The pair of pistons cooperate with the housing and with each other to substantially define a pair of pressure chambers which are communicated with respective brake assemblies. A first piston of the pair of pistons is movable within the housing to pressurize a primary pressure chamber and the second piston of the pair of pistons is movable in response to pressurized fluid within the primary pressure chamber so as to pressurize a secondary pressure chamber. The second piston carries a valve assembly and includes a passage to provide fluid communication between the secondary pressure chamber and its respective brake assembly.

Abstract: A tandem master cylinder assembly for use in split-type hydraulic brake systems of an automotive vehicle, comprising a fluid reservoir, a cylinder body having a cylinder bore communicable with the fluid reservoir through two ports formed in the cylinder body, primary and secondary pistons axially slidable as a single unit in the cylinder bore, a floating piston axially movable within the secondary piston and forming, jointly with the primary and secondary pistons, primary and secondary pressure chambers which are variable in volume depending upon the axial positions of the primary and secondary pistons relative to the cylinder body and the axial position of the floating piston relative to the cylinder body and to the secondary piston, and means to limit the distance of travel of the floating piston relative to the cylinder body.

Abstract: There is disclosed a brake force regulator for a motorcycle hydraulic brake system wherein the pressure from a pedal-operated master cylinder is adapted to actuate a rear-wheel brake and a front-wheel brake, and the pressure from a hand-operated master cylinder is adapted to actuate another front-wheel brake. In this brake system, the brake force regulator provides for reduced supply of pressure to the rear-wheel brake dependent on the pressure from the hand-operated master cylinder when both master cylinders are actuated simultaneously. If only the hand-operated master cylinder is actuated, this will not have any effect on the rearwheel brake.

Abstract: A two stage master cylinder having a bore with a first diameter and a second diameter separated by a shoulder. A first piston is located in the first diameter of the bore to establish a first chamber. A second piston has a first section located in the first diameter of the bore to establish a second chamber and a second section located in the second diameter of the bore to establish an actuation chamber therein. A first passage in the second piston connects the actuation chamber with the second chamber. A second passage in the second piston connects the first passage to a reservoir in the housing. A shuttle piston located in the first passage has a first surface area exposed to the second chamber and a second smaller surface area exposed to the actuation chamber. A spring urges the shuttle piston toward the second chamber. An input force from an operator moves the second piston causing fluid to flow from the actuation chamber through the first passage to the second chamber.

Abstract: A tandem master cylinder comprises two pistons, one of which includes a cylindrical bore for receiving therein the other piston, and limiting means for limiting the axial movement of the other piston.

Abstract: A fluid motor having a housing with a stepped bore for retaining a first piston and a second piston. A sleeve is located in the stepped bore to permit the first piston and the second piston to be of substantially the same diameter. A plug attached to the housing holds the sleeve in the stepped bore. A spring attached to the sleeve holds the first piston against a stop. The spring acts on the sleeve to create a gap with a shoulder in the stepped bore. The second piston which is connected to the first piston through a linkage mechanism carries a concentric shuttle piston. The shuttle piston is subjected to a first hydraulic pressure created by the first piston and to a second hydraulic pressure created by the second piston. An indicator is connected to the shuttle piston and remains inactive when the first and second hydraulic pressures are substantially equal.

Abstract: A brake booster for use in a braking system having a control valve which is responsive to a hydraulic output force created by manually moving a piston in a bore of a master cylinder. The hydraulic output force actuates the control valve which proportionally directs a portion of the fluid output of a pump which supplies a power steering gear with hydraulic fluid, into the bore. This portion of the output of the pump acts on the piston and provides an auxiliary force for moving the piston through which the hydraulic output force is created. When the hydraulic output force of the brake booster reaches a predetermined value, the control valve engages a stop member to limit the diversion of the fluid output from the pump and thereby assure that a minimal quantity of the fluid output is continually available to operate the power steering gear.