Abstract: In screw rotors (21, 22) which are each provided with a screw tooth (211, 221) having a spiral addendum surface portion (211a, 221a) and a deddendum surface portion (211c, 221c), and are used as a pair of male and female, between the addendum surface portion (211a, 221a) and deddendum surface portion (211c, 221c) of the screw tooth (211, 221), there is provided the pitch circumference portion (211p, 221p) which forms a predetermined angle range of circular arc having a definite radius rp on an optional transverse cross section, and the radius of the pitch circumference portion (211p, 221p) is set such that, when the opposing rotors are meshed with each other, out of the meshing clearances between the male and female screw teeth (211, 221), the clearance g1 between the pitch circumference portions (211p, 221p) becomes smaller than the clearances g2, g3, g4 between the other portions.

Abstract: An evacuating apparatus having a high energy efficiency when the suction side pressure has reached the ultimate pressure or become a certain degree of vacuum, by decreasing the motive power owing to differential pressure. The evacuating apparatus (100) having a roughing vacuum pump (B) and a booster pump (A), each of which is constituted by a screw vacuum pump, wherein the design pumping speed of the roughing vacuum pump (B) is sufficiently smaller than the design pumping speed of the booster pump (A), but adequate to be operable as the roughing vacuum pump, and the number of turns of screw for the booster pump (A) is less than the number of turns of screw for the roughing vacuum pump (B).

Abstract: If a hydraulic motor (23) (traveling wheel (27)) is rotated (or skidding) at high rate, and a hydraulic motor (24) is hardly rotated, a detection controller (68) compares the rotational speeds of both hydraulic motors (23, 24). Then the rotation detected by the rotation detectors (66, 67) to detect the traveling wheel (27) to be skidding, and moves a piston (71) to allow a negative brake (40) to give a braking force to the hydraulic motor (23), and rotate the hydraulic motor (24). In this way, this invention can release the traveling wheel from skidding without the use of a flow dividing valve.

Abstract: A traction drive speed reducer which comprises circumscribed axes 20A and 20B, a plurality of intermediate axes 30A and 30B arranged contacting around the outer periphery of the circumscribed axes, and inscribed cylinders 40A and 40B inscribing the outer periphery of the intermediate axes, and in which a supporting member 10 to rotatably support the intermediate axes is fixed, a drive motor is connected to at least one of the plurality of intermediate axes, and an output is taken from the circumscribed axis having the larger diameter than the outer diameter of the intermediate axis.

Abstract: In a brake (53) for a hydraulic motor (10), a braking piston (66) is added that can move toward and away from fixed friction discs (54) and rotating friction discs (55). A braking passage (73) leads a high-pressure fluid into the braking piston (66) to press the braking piston (66) to the friction discs (54, 55).

Abstract: An optical stereolithographic apparatus performs optical stereolithography by preparing a mask on a light-transmissible member (31) on the basis of data for one layer with respect to optical stereolithography, exposing an unhardened resin layer (96) of photohardenable resin to light through the mask, and repeating an exposure operation. The optical stereolithographic apparatus has an optical system in which the light-transmissible member (31) and the unhardened resin layer (96) are spaced from each other at a predetermined distance, and the unhardened resin layer (96) of the photohardenable resin is subjected to a projection exposure through the mask.

Abstract: An eccentric orbiting type speed reducer for the joint of the industrial machine has a plurality of crankshafts, a rotational driving force being input into one crankshaft alone among the plurality of crankshafts, in which the bearing capacity for one crankshaft among the plurality of crankshafts is greater than the bearing capacities for other crankshafts.

Abstract: A pressure detecting apparatus includes: a housing (11) for forming fluid chambers (21A and 21B) into which external fluid pressures are imported respectively; a pressure-receiving member (31) slidably provided in the housing (11) for receiving the fluid pressures from the fluid chambers (21A and 21B); an elastic member (35) supported by the housing (11) and elastically deformed due to a slide displacement of the pressure-receiving member (31) from a predetermined position; a displacement detecting means (12) for detecting the displacement of the pressure-receiving member (31) from the predetermined position; the elastic member including a base portion supported by the housing, an engagement portion engaged with the pressure-receiving member, and a flexible arm extending from the base portion toward the engagement portion along a plane approximately perpendicular to a direction of sliding of the pressure-receiving member.

Abstract: In a relaxation-heating method and an apparatus therefor, relaxation-heating is performed by a heating apparatus which is provided between a yarn supply roller (5) and a take-up roller (7) having a speed lower than that of the supply roller (5) and which is constituted by a heating roller (6a) and an auxiliary bobbin (6b). In the relaxation-heating method and an apparatus therefor, the size is compact, the heat conductivity is high and yarn can be made to run at a high speed.

Abstract: A sealing mechanism comprises a support member forming part of the semiconductor producing apparatus which has a vacuum chamber, a rotation shaft rotatably received in the support member, and at least three seal rings axially spaced apart from each other between the support member and the rotation shaft to form a first fluid chamber close to the atmosphere and a second fluid chamber close to the vacuum chamber. The first fluid chamber is vacuumized to have a first pressure, and the second fluid chamber is also vacuumized to have a second pressure which is lower than the first pressure. The first and second fluid chambers work together to enhance the sealing performance of the sealing mechanism.

Abstract: A traction drive type driving apparatus is provided, by which any particular pressing mechanism is unnecessary, by which a big deformation can be obtained easily, in which decreasing degree of the pressing load is extremely small against small amount of abrasion, in which the test for confirming the pressing load at a desired amount can be done easily, and which has a readily constructible hollow structure. The traction drive type driving apparatus comprises an externally contacting shaft (2) located at the center, a plurality of intermediate shafts (1) equidistantly disposed around and externally contacting with the externally contacting shaft (2), and an internally contacting cylinder (3) internally contacting with the intermediate shafts (1), at least one of the intermediate shafts offset from the center is an input shaft, and the externally contacting shaft (2) is a ring-like hollow cylinder and is held by the intermediate shafts (1) to form a floating ring without disposing any particular bearing.

Abstract: In screw rotors (21, 22) which are each provided with a screw tooth (211, 221) having a spiral addendum surface portion (211a, 221a) and a deddendum surface portion (211c, 221c), and are used as a pair of male and female, between the addendum surface portion (211a, 221a) and deddendum surface portion (211c, 221c) of the screw tooth (211, 221), there is provided the pitch circumference portion (211p, 221p) which forms a predetermined angle range of circular arc having a definite radius rp on an optional transverse cross section, and the radius of the pitch circumference portion (211p, 221p) is set such that, when the opposing rotors are meshed with each other, out of the meshing clearances between the male and female screw teeth (211, 221), the clearance g1 between the pitch circumference portions (211p, 221p) becomes smaller than the clearances g2, g3, g4 between the other portions.

Abstract: A yarn feeding device including a preheater 23 for preheating a yarn bar Y, a first feed roller 27 for drawing the yarn bar Y from an original yarn package 11 is provided opposite to a temporary twisting and relaxation heat treating device including a second feed roller having a higher circumferential speed than that of the first feed roller 27, a temporary twisting tool 31 for twisting the yarn bar Y and a second heater 35 for carrying out a relaxation heat treatment on the temporary twisted yarn bar Y with a worker passage A interposed therebetween, a first heater 41 and a cooling plate which thermally fix a twist retroacting along the yarn bar Y are provided in portions positioned above from the yarn feeding device to the temporary twisting and relaxation heat treating device, and a winding device 51 including an automatic switching device is provided on an opposite worker passage A side of the temporary twisting and relaxation heat treating device.

Abstract: In a speed reducer, because the idler gears 62 that mesh with the drive gear 58 and the external gears 55 fixed to the crankshafts 45 are provided between those gears 55 and 58, the reduction of the diameters of the external gears 55 and the drive gear 58 can be easily accomplished. Consequently, the inertia moment, and hence the size of the servomotor for driving, become smaller, and vibration and the noise caused by engagement can be reduced as well. The radial distance L between the crankshaft 45 and the center axis Z of the speed reducer 64 can be easily increased to improve the rigidity of the speed reducer 64 in the circumferential direction.

Abstract: There is provided a photocurable resin composition comprising (A) an urethane acrylate having three or four acrylate groups in the molecule, (B) a radical polymerizable compound different from the above urethane acrylate; and (C) a photopolymerization initiator, the weight ratio of the urethane acrylate (A) to the radical polymerizable compound (B) being 80:20 to 10:90; and a production process thereof. The said photocurable resin composition can provide moldings and stereolithographed objects having excellent dimensional accuracy with a small volume shrinkage factor at the time of photo-curing and excellent heat resistance with a high thermal deformation temperature as well as excellent transparency and mechanical properties such as tensile strength.

Abstract: An internally meshing planetary gear device which comprises an internal gear having a circular arc tooth form and an outer gear of a planetary gear having an epitrochoid tooth form, the internal gear comprises pins, both ends of which are supported, and rolling bearings inserted onto the pins, and the rolling bearings have outer races meshing with the outer gear.

Abstract: An electromagnetic force motor comprising: a magnetic housing having a housing chamber formed therein; a stationary magnetic member received in the housing chamber in stationary relationship with respect to the magnetic housing; a movable magnetic member received in the housing chamber to be movable with respect to the stationary magnetic member, the stationary magnetic member, and the movable magnetic member forming with a magnetic flux gap to permit a magnetic flux to pass therethrough, the magnetic housing, the stationary magnetic member, and the movable magnetic member each made of a magnetic substance and collectively forming a magnetic circuit unit that is to allow a magnetic flux to pass therethrough; a permanent magnet positioned in the housing chamber and generating a magnetic flux; and an electromagnetic coil positioned in the housing chamber and generating a magnetic flux with an electric current imparted thereto, the magnetic circuit unit partly having a diminished cross-sectional area being small

Abstract: A resin composition for forming a three-dimensional object by optical stereolithography, which contains 5 to 65 vol % of aluminum oxide fine particles having an average particle diameter of 3 to 70 &mgr;m and 5 to 30 vol % of whiskers having a diameter of 0.3 to 1 &mgr;m, a length of 10 to 70 &mgr;m and an aspect ratio of 10 to 100, the total content of the aluminum oxide fine particles and the whiskers being 10 to 70 vol %. According to the resin composition for forming a three-dimensional object by optical stereolithography, a high-quality three-dimensional object by optical stereolithography that has high heat resistance with a high heat distortion temperature and high rigidity with a high flexural modulus and that is free from a dimensional change on account of a low linear thermal expansion coefficient even when temperature varies can be obtained by optical stereolithography with high dimensional accuracy.

Abstract: A resin composition for stereolithography and a process for producing a three-dimensional object using the same. The resin composition comprises (1) a liquid photohardenable resin composition containing at least one of photo-polymerizable compounds and a photosensitive polymerization initiator, and (2) at least one of radiation energy absorbers in an amount of from 0.001 to 1.0% by weight based on the total amount of the liquid photohardenable resin composition (1).

Abstract: A traction drive type driving apparatus is provided, by which any particular pressing mechanism is unnecessary, by which a big deformation can be obtained easily, in which decreasing degree of the pressing load is extremely small against small amount of abrasion, in which the test for confirming the pressing load at a desired amount can be done easily, and which has a readily constructible hollow structure. The traction drive type driving apparatus comprises an externally contacting shaft (2) located at the center, a plurality of intermediate shafts (1) equidistantly disposed around and externally contacting with the externally contacting shaft (2), and an internally contacting cylinder (3) internally contacting with the intermediate shafts (1), at least one of the intermediate shafts offset from the center is an input shaft, and the externally contacting shaft (2) is a ring-like hollow cylinder and is held by the intermediate shafts (1) to form a floating ring without disposing any particular bearing.