Abstract: An eccentric oscillating speed reducer includes an input rotor, a first rotor, a second rotor, a planetary rotor, a flow passage, a contact portion and a radial relief groove. The flow passage includes an axial gap located between the planetary rotor and a contact member. The flow passage conducts a lubricant oil that is forced to flow by a centrifugal force. The contact portion is placed in a drive force transmission path from the planetary rotor to the second rotor. The contact portion includes: a planetary rotor end surface of the planetary rotor located on a side where the second rotor is placed; and a second rotor end surface of the second rotor, which is opposed to the planetary rotor end surface. The radial relief groove forms a portion of the flow passage and extends through a radial width of the planetary rotor end surface.

Abstract: An eccentric oscillating speed reducer includes an input rotor, a first rotor, a second rotor, a planetary rotor, a flow passage, a contact portion and a radial relief groove. The flow passage includes an axial gap located between the planetary rotor and a contact member. The flow passage conducts a lubricant oil that is forced to flow by a centrifugal force. The contact portion is placed in a drive force transmission path from the planetary rotor to the second rotor. The contact portion includes: a planetary rotor end surface of the planetary rotor located on a side where the second rotor is placed; and a second rotor end surface of the second rotor, which is opposed to the planetary rotor end surface. The radial relief groove forms a portion of the flow passage and extends through a radial width of the planetary rotor end surface.

Abstract: Each of an external tooth-bottom surface and an external bottom-side contact surface has a cross-sectional shape formed by a hypocycloid curved line. An external front-side contact surface has a cross-sectional shape formed by an epicycloid curved line. An external tooth-front surface is formed at a radial-inside position of a reference epicycloid curved line, that is, a position closer to a first pitch circle of an external gear. A possible contact between a tooth-front portion of the external gear and a tooth-front portion of an internal gear can be avoided. A connecting point between the external tooth-front surface and the external front-side contact surface is located at such a position that a contact surface length of an external tooth-contact surface is larger than twenty percent of a total tooth surface of the external gear.

Abstract: A second rotor and a third rotor are accommodated in a first rotor. A fitting portion of the third rotor is located in an engagement hole of the second rotor to engage the third rotor with the second rotor. The third rotor is rotational about an axis, which is eccentric to an axis of the first rotor, to vary a relative rotational phase of the first rotor to the second rotor and to accelerate and decelerate rotation of the second rotor. When friction arises between the second rotor and the fitting portion, a frictional force acts in a direction to reduce a rotational moment acting on the third rotor. A friction coefficient between the second rotor and the fitting portion is greater than a friction coefficient between ferrous objects.

Abstract: Each of an external tooth-bottom surface and an external bottom-side contact surface has a cross-sectional shape formed by a hypocycloid curved line. An external front-side contact surface has a cross-sectional shape formed by an epicycloid curved line. An external tooth-front surface is formed at a radial-inside position of a reference epicycloid curved line, that is, a position closer to a first pitch circle of an external gear. A possible contact between a tooth-front portion of the external gear and a tooth-front portion of an internal gear can be avoided. A connecting point between the external tooth-front surface and the external front-side contact surface is located at such a position that a contact surface length of an external tooth-contact surface is larger than twenty percent of a total tooth surface of the external gear.

Abstract: A second rotor and a third rotor are accommodated in a first rotor. A fitting portion of the third rotor is located in an engagement hole of the second rotor to engage the third rotor with the second rotor. The third rotor is rotational about an axis, which is eccentric to an axis of the first rotor, to vary a relative rotational phase of the first rotor to the second rotor and to accelerate and decelerate rotation of the second rotor. When friction arises between the second rotor and the fitting portion, a frictional force acts in a direction to reduce a rotational moment acting on the third rotor. A friction coefficient between the second rotor and the fitting portion is greater than a friction coefficient between ferrous objects.

Abstract: An eccentric speed variator includes a first rotor, a second rotor, a third rotor, a cylindrical pin, and a flange. The second rotor has a hole formed therein. The third rotor rotates eccentrically to change a relative rotation phase between the first and second rotors. The cylindrical pin extends through the hole of the second rotor to establish mechanical engagement between the second and third rotors. The flange is secured to or integrally formed with an end of the cylindrical pin. In operation, when the flange contacts the outside wall of the second rotor, it serves to minimize inclination of the third rotor relative to the second rotor, thereby reducing local friction between the second and third rotors to eliminate undesirable mechanical vibration or noise. This structure also enables parts of the cycloidal speed reducer to be decreased, which leads to a reduced size of the cycloidal speed reducer.

Abstract: An eccentric speed variator includes a first rotor, a second rotor, a third rotor, a cylindrical pin, and a flange. The second rotor has a hole formed therein. The third rotor rotates eccentrically to change a relative rotation phase between the first and second rotors. The cylindrical pin extends through the hole of the second rotor to establish mechanical engagement between the second and third rotors. The flange is secured to or integrally formed with an end of the cylindrical pin. In operation, when the flange contacts the outside wall of the second rotor, it serves to minimize inclination of the third rotor relative to the second rotor, thereby reducing local friction between the second and third rotors to eliminate undesirable mechanical vibration or noise. This structure also enables parts of the cycloidal speed reducer to be decreased, which leads to a reduced size of the cycloidal speed reducer.

Abstract: An upper die and a lower die are combined. A core for molding a concavity and another core are combined with the combined upper die and the lower die at respective prescribed positions. A core for through-hole molding is constructed by the junction of cores that are severally formed with the upper die and the lower die integrally on the extension line of the central axis of the core for molding a concavity. A through-hole is molded with the core for through-hole molding. A concavity in which a valve mechanism is equipped and a communicating hole through which the concavity communicates with the through-hole are molded with the core for molding a concavity. The core for through-hole molding includes an impact hole, in which a tip of the core for molding a concavity is impacted.

Abstract: A master cylinder including a cylinder body having a cylindrical bore and an opening in the circumferential wall for a relief port communicating with the interior of hydraulic reservoir. A piston is slidably inserted into the cylindrical bore to form a hydraulic pressure generating chamber in the cylindrical bore. A cup seal is provided with an inner circumferential lip portion contacting with the piston, an outer circumferential lip portion slidably contacting with the inner circumferential wall of the cylindrical bore, and a base portion connecting the lip portions, which are so arranged as to face to the hydraulic pressure generating chamber. The cup seal cuts the communication between the hydraulic pressure generating chamber and the hydraulic reservoir through the relief port when the top end of the outer circumferential lip portion passes by the relief port.

Abstract: To provides a technique capable of replenishing a working fluid smoothly while employing a method for replacing an atmospheric air with the working fluid. The reservoir apparatus (10) includes a main reservoir (20) having an inlet opening for feeding a hydraulic fluid, and an auxiliary reservoir (50) connecting thereto through a piping (30). There is a diagonally extending connecting pipe (60) at the auxiliary reservoir (50). There is a recessed portion (80) at an opening portion (64) of an inner periphery of the connecting pipe (60). This recessed portion (80), when compared with the case where there is no such a recessed portion, serves to enlarge the opening portion (64) of the connecting pipe (60) and more smoothly flow the replenishment working fluid at a nearby area of the opening portion (64).

Abstract: In a master cylinder including: a cylinder body having a cylindrical bore and an opening made in the circumferential wall, for a relief port communicating with the interior of hydraulic reservoir, a piston inserted slidably into said cylindrical bore to form a hydraulic pressure generating chamber in said cylindrical bore; and a cup seal having an inner circumferential lip portion contacting with said piston, an outer circumferential lip portion slidably contacting with the inner circumferential wall of said cylindrical bore, and a base portion connecting said lip portions which are so arranged as to face to said hydraulic pressure generating chamber, whereby said cup seal cuts the communication between said hydraulic pressure generating chamber and said hydraulic reservoir through said relief port when the top end of said outer circumferential lip portions passes by said relief port, the improvement in which means for rotating said cup seal relative to said cylindrical bore with the movement of said piston i

Abstract: To provides a technique capable of replenishing a working fluid smoothly while employing a method for replacing an atmospheric air with the working fluid. The reservoir apparatus 10 includes a main reservoir 20 having an inlet opening for feeding a hydraulic fluid, and an auxiliary reservoir 50 connecting thereto through a piping 30. There is a diagonally extending connecting pipe 60 at the auxiliary reservoir 50. There is a recessed portion 80 at an opening portion 64 of an inner periphery of the connecting pipe 60. This recessed portion 80, when compared with the case where there is no such a recessed portion, serves to enlarge the opening portion 64 of the connecting pipe 60 and more smoothly flow the replenishment working fluid at a nearby area of the opening portion 64. By doing so, the opening portion 64 of the connecting pipe 60 can be more enlarged at the time of replenishment of the working fluid and formation of a film of the working fluid can be prevented at the opening portion 64.

Abstract: An upper die and a lower die are combined. A core for molding a concavity and another core are combined with the combined upper die and the lower die at respective prescribed positions. A core for through-hole molding is constructed by the junction of cores that are severally formed with the upper die and the lower die integrally on the extension line of the central axis of the core for molding a concavity. A through-hole is molded with the core for through-hole molding. A concavity in which a valve mechanism is equipped and a communicating hole through which the concavity communicates with the through-hole are molded with the core for molding a concavity. The core for through-hole molding includes an impact hole, in which a tip of the core for molding a concavity is impacted.

Abstract: There are disclosed a process for producing the optically active cyclic amino acid ester derivative of the formula (I): by optical resolution method, a process for producing the same and a process for producing an optically active cyclic amino acid using the compound of the formula (I).

Abstract: The present invention provides a process for preparing optically active azetidine-2-carboxylic acids using readily available reagents of relatively low price in the industry. Thus, there is provided optically active azetidine-2-carboxylic acid, and a process for producing the same by subjecting optically active N-(alkylbenzyl)azetidine-2-carboxylic acid represented by the formula (1): ##STR1## to hydrogenolysis in the presence of a catalyst.

Abstract: The present invention provides a process for preparing optically active azetidine-2-carboxylic acids using readily available reagents of relatively low price in the industry. Thus, there is provided optically active azetidine-2-carboxylic acid, and a process for producing the same by subjecting optically active N-(alkylbenzyl)azetidine-2-carboxylic acid represented by the formula (1): ##STR1## to hydrogenolysis in the presence of a catalyst.

Abstract: A hindered piperidine compound represented by the formula of ##STR1## wherein R.sup.1 is a 2,2,6,6-tetramethyl-4-piperidyl group of which the N-position is substituted or not, a hydrogen atom, a C.sub.1 -C.sub.18 arylalkyl group which may contain a cyclic portion, or a C.sub.7 -C.sub.18 arylalkyl group, R.sup.2 is a hydrogen atom, a C.sub.1 -C.sub.10 alkyl group which may contain a cyclic portion, a C.sub.1 -C.sub.18 alkyloxy group which may contain a cyclic portion, or a hydroxyl group, and n is an integer of 2 to 8, effectively stabilizes organic materials having a property to deteriorate by the action of light. A method for producing the compound represented by the above formula is also disclosed.

Abstract: A hindered piperidine compound represented by the formula of ##STR1## wherein R.sup.1 is a 2,2,6,6-tetramethyl-4-piperidyl group of which the N-position is substituted or not, a hydrogen atom, a C.sub.1 -C.sub.18 alkyl group which may contain a cyclic portion, or a C.sub.7 -C.sub.18 arylalkyl group, R.sup.2 is a hydrogen atom, a C.sub.1 -C.sub.10 alkyl group which may contain a cyclic portion, a C.sub.1 -C.sub.18 alkyloxy group which may contain a cyclic portion, or a hydroxyl group, and n is an integer of 2 to 8, effectively stabilizes organic materials having a property to deteriorate by the action of light. A method for producing the compound represented by the above formula is also disclosed.

Abstract: A hindered piperidine compound represented by the formula of ##STR1## wherein R.sup.1 is a 2,2,6,6-tetramethyl-4-piperidyl group of which the N-position is substituted or not, a hydrogen atom, a C.sub.1 -C.sub.18 alkyl group which may contain a cyclic portion, or a C.sub.7 -C.sub.18 arylalkyl group, R.sup.2 is a hydrogen atom, a C.sub.1 -C.sub.10 alkyl group which may contain a cyclic portion, a C.sub.1 -C.sub.18 alkyloxy group which may contain a cyclic portion, or a hydroxyl group, and n is an integer of 2 to 8, effectively stabilizes organic materials having a property to deteriorate by the action of light. A method for producing the compound represented by the above formula is also disclosed.