An electric linear motion actuator includes planetary rollers mounted between the radially inner surface of an outer ring member and the radially outer surface of a rotary shaft, and a carrier rotatable about the rotary shaft and including radially movable roller shafts rotatably supporting the respective planetary rollers. Elastic rings each having circumferentially separate ends are each wrapped around the roller shafts to radially inwardly bias the roller shafts, thereby bringing the respective planetary rollers into elastic contact with the radially outer surface of the rotary shaft. Each elastic ring is prevented from rotating relative to the roller shafts, thereby preventing one of the roller shafts from being axially aligned with the gap between the circumferential separate ends, causing the elastic ring to be radially compressed and thus making it impossible for the elastic rings to radially bias the roller shafts.

Electric linear motion actuator and electric brake system

A solenoid valve for a brake system, which has a simple constitution and can be easily manufactured with reduced manufacturing costs, is disclosed. A valve core is formed in a cylindrical shape, and has a through-hole formed in a longitudinal direction of the valve core and a fluid passage formed in a radial direction of the valve core so as to communicate with the through-hole. A sleeve is coupled to an outer surface of the valve core. The sleeve has a dome-shaped shielding portion at one end, and a flange portion to be fixed to a modulator block at the other end. An armature is slidably mounted in the sleeve. An exciting coil is provided to move the armature. A valve seat is fixed in the valve core, and has a first orifice. A plunger is mounted in the valve core. The plunger moves by movement of the armature to open or close the first orifice. A restoring spring is provided to press the plunger toward the armature. A filter member is coupled to the valve core to surround an outer surface and an end portion of the valve core, which are to be received in a bore of the modulator block. The filter member includes a filtering part to filter oil, a second orifice to rectify oil flow, and a check valve to permit oil to flow back when braking operation is released.

Solenoid valve for brake system

PROBLEM TO BE SOLVED: To prevent the contact of a helical projected thread with the edge portion of a groove when the helical projected thread is engaged with circumferential or helical grooves, and further to prevent the partial contacts of the side surface of the helical projected thread, which is engaged with the grooves, with the side walls of the grooves on the base portion side or the top portion side. SOLUTION: The side wall of the helical groove 7a of a planetary roller 7 is tilted such that the width of the groove increases from the bottom side of the groove toward the edge side of the groove. Further, the side surface of the helical projected thread of an outer ring member 5 is tilted such that the width of the thread decreases from the root portion of the thread toward the top side. Further, the side surface of the tilted helical projected thread is formed so as to be a circular arc surface 5c which is convex with respect to the tilted direction. As a result, the contact of the helical projected thread with the edge portion of the groove is prevented when the helical projected thread is engaged with the helical groove 7a, and further the partial contacts of the side surface of the helical projected thread engaged with the helical groove 7a with the side wall of the helical groove 7a on the root side and the tip end side is prevented. COPYRIGHT: (C)2009,JPO&INPIT

Electric linear motion actuator and electric brake device

An electric linear motion actuator including: a locking mechanism capable of locking and unlocking the rotation of a rotor shaft (12) of an electric motor (11); wherein the locking mechanism includes: a plurality of locking holes (41) provided in the side surface of one (33) of a plurality of gears constituting a reduction gear mechanism (13) so as to be arranged in the circumferential direction of the one (33) of the plurality of gears; a locking pin (42) configured to be moved forward and backward with respect to the locking holes (41), and brought into engagement with one of the locking holes (41) to lock the gear (33) when the locking pin (42) is moved forward; and a linear solenoid (43) configured to move the locking pin (42) forward and backward. In this electric linear motion actuator, a plunger (49) provided in the linear solenoid (43) and the locking pin (42) are formed as separate parts, and disposed on the same axis such that one of the end surfaces of the linear solenoid (43), and of the locking pin (42), face each other in the axial direction. This prevents the moment load applied by the gear (33) to be locked to the locking pin (42) from acting on the plunger (49), thereby preventing a bobbin (48) slidably supporting the radially inner surface of the plunger (49) from being damaged. Further, the locking pin (42) is made of a non-magnetic material so that the magnetism of the magnetic circuit formed between a coil (47) of the linear solenoid (43) and the plunger (49) can be prevented from leaking through the locking pin (42). This allows the plunger (49) to be reliably attracted and moved by the magnetism when the coil (47) is energized, thereby improving the reliability of the locking operation.

Electric direct-acting actuator and electric disc-brake device

An exemplary control device includes an input torque detection unit that detects an input torque input to the input shaft; and a controller that: determines torque distribution of two of the friction engagement elements that form the shift speeds; and calculates a transmission torque of the two friction engagement elements based on the input torque and the torque distribution and sets the engagement pressure to obtain a torque capacity that can transmit the transmission torque, wherein the controller sets the engagement pressure such that slippage does not occur in the two friction engagement elements in a state where engagement of the two friction engagement elements forms the shift speeds and such that, even if an additional friction engagement element engages based on the line pressure while the two friction engagement elements are engaged, one of the three friction engagement elements is caused to slip.

Control device for automatic transmission

A linear solenoid valve includes a solenoid having a coil wound around a coil bobbin, a fixed core, and a movable core for being attracted to the fixed core when the coil is energized, and a valve mechanism having a valve element for selectively bringing an inlet port and an outlet port into and out of fluid communication with each other responsive to a displacement of the movable core. The movable core has a nonmagnetic layer formed on an outer surface thereof and having a predetermined thickness.

Linear solenoid valve

A normally open hydraulic control valve includes: a linear solenoid unit; a spool driven by an output force of the linear solenoid unit to move forward; a valve body in which the spool is fitted; and a return spring for biasing the spool in a retreating direction. The valve body includes: a reaction force oil chamber for introducing hydraulic pressure, which presses the spool in a direction against a biasing force of the return spring, from the output port; and a damper oil chamber which suppresses vibration of the spool. The damper oil chamber is adjacent to the reaction force oil chamber with the third land portion of the spool therebetween. A slide gap which leaks and supplies oil from the reaction force oil chamber to the damper oil chamber is provided between the third land portion and the valve body. Thus, it is possible to quickly supply the oil to the damper oil chamber at the early stage of the operation without restriction on the arrangement, and to prevent delay in operation of the damper oil chamber.

Normally open hydraulic control valve

A damper device for a hydraulic control valve includes: a valve body; a damper oil chamber to which one end surface of a spool is faced; an oil reservoir chamber which is adjacent to the damper oil chamber with a partition wall therebetween; and an orifice provided in the partition wall to allow an upper portion of the damper oil chamber to communicate with the oil reservoir chamber. The damper oil chamber and the oil reservoir chamber are disposed in the valve body. The oil reservoir chamber is constructed by closing an opening of a recessed portion formed on an undersurface of the valve body with a top surface of the support member for supporting the valve body. In order to work the orifice in the partition wall by drilling from the opening of the recessed portion, an axis of the orifice is disposed to pass through the opening of the recessed portion. Thus, it is possible to eliminate need for post-treatment after working the orifice, thereby reducing the cost.

Damper device for hydraulic control valve

PROBLEM TO BE SOLVED: To secure hydraulic supply to an actuator even in the case of any abnormal condition on side of a control valve while making it possible to axially miniaturize the control valve, in a hydraulic control device provided with a spool type control valve which is provided with between a hydraulic source and the actuator, by controlling in accordance with thrust force with which a linear solenoid displays output hydraulic pressure in the hydraulic source. SOLUTION: The device allows a valve housing 19 of the control valve 13 to shut off between the actuator and the control valve 13 in accordance with manual operation, and at the same time is arranged with a manually operated valve 50 which routes the control valve 13 and permits the hydraulic source to be in fluid communication with the actuator by including axis of actuation parallel to axis of the linear solenoid 14. COPYRIGHT: (C)2004,JPO

Hydraulic control device

PROBLEM TO BE SOLVED: To provide a oil pressure control valve which can give always a stable damping force to a spool, prevent oscillation certainly and be also able to be composed compactly SOLUTION: This oil pressure control valve is provided with a linear solenoid part S, the spool 22 being driven forward by the output of the linear solenoid part S, the valve case 20 and the return spring 23 of a spool 22, and the supply port 37, the output port 38 and the drain port 39 are provided in the valve case 20 In the oil pressure control valve so as to draw out the output oil pressure from the supply port 37 to the output port 38 according to the output of the linear solenoid part S, the end surface of the spool 22 facing the valve case 20 and the damper oil chamber 36 encasing the return spring 23 and the oil reservoir chamber 49 just adjacent to this damper oil chamber 36 are provided And an orifice 50, which communicates with the damper oil chamber 36 and the oil reservoir chamber 49, are bored and installed at the upper part of the bulkhead between the damper oil chamber 36 and the oil reservoir chamber 49

Hidetoshi Watanabe

Papers

Linear solenoid valve

Normally open hydraulic control valve

Damper device for hydraulic control valve

Hydraulic control device

Oil pressure control valve