Abstract: There is provided a ball screw that is used to apply a preload to balls and that has a configuration of achieving a balance between the cooling efficiency and ease of assembly and disassembly. To this end, the ball screw includes a screw shaft, and a plurality of nuts movable relative to the screw shaft in an axial direction. Each of the nuts includes flow channels, which are cooling mechanisms and which respectively serve as independent channels to allow a cooling medium to pass through them. These flow channels are provided symmetrically with respect to a space between the nuts, and are configured so that the cooling medium can independently circulate in each of the nuts.

Abstract: There is provided a ball screw that is used to apply a preload to balls and that has a configuration of achieving a balance between the cooling efficiency and ease of assembly and disassembly. To this end, the ball screw includes a screw shaft, and a plurality of nuts movable relative to the screw shaft in an axial direction. Each of the nuts includes flow channels, which are cooling mechanisms and which respectively serve as independent channels to allow a cooling medium to pass through them. These flow channels are provided symmetrically with respect to a space between the nuts, and are configured so that the cooling medium can independently circulate in each of the nuts.

Abstract: To improve workability and sealing performance of a coolant when a plurality of nuts in a ball screw are brought into contact with one another, the plurality of nuts being coupled to one another, assembled to one threaded shaft and cooled by flowing the coolant through through-holes formed in the plurality of nuts in axial directions of the plurality of nuts. The ball screw includes counterbores of the through-holes formed on opposing end faces of both of adjoining nuts, and a ring-shaped sealing member inserted thereto. The counterbores are formed such that a depth of one counterbore is larger than a length of the sealing member, and the a depth of the other counterbore is smaller than the length of the sealing member, and such that circumferential positions of the counterbores of the adjoining nuts face each other when a desired preload is exerted.

Abstract: There is provided a ball screw apparatus ensuring easy and proper centering between a nut and a stationary member. Therefore, the ball screw apparatus (1) has a threaded shaft (10), a nut (20) that passes through the threaded shaft (10) and is screwed via a rolling body B into the threaded shaft (10) so as to be disposed movable in the axial direction of the threaded shaft (10), and a stationary member (40). The stationary member (40) is secured to an end surface (20a) of the nut (20), and a dustproof member (60) that prevents entry of foreign matter into the nut (20) is secured to the stationary member (40). The end surface (20a) of the nut (20) is provided with a spigot joint portion (20b) fitted to an outer circumferential surface (42a) of a flange part (42) of the stationary member (40).

Abstract: A ball screw apparatus is provided which is less likely to increase dynamic friction torque even when a nut is contracted by cooling, and in which cooling effect is made as high as possible and which does not invite excessive machining efficiency droop and increase in pressure loss. The ball screw apparatus includes a screw shaft, a nut screwed with the screw shaft via a plurality of balls, and a cooling section cooling the nut. The plurality of balls to which preload is applied in a two-point contact state, with a preload direction as a tensile direction, are disposed between a screw groove of the screw shaft and a screw groove of the nut. Or, a ratio of the axial length L of the through hole axially formed in the nut and the diameter D of the through hole axially formed in the nut is given by an equation “10?L/D?60”.

Abstract: To improve workability and sealing performance of a coolant when a plurality of nuts in a ball screw are brought into contact with one another, the plurality of nuts being coupled to one another, assembled to one threaded shaft and cooled by flowing the coolant through through-holes formed in the plurality of nuts in axial directions of the plurality of nuts. The ball screw includes counterbores of the through-holes formed on opposing end faces of both of adjoining nuts, and a ring-shaped sealing member inserted thereto. The counterbores are formed such that a depth of one counterbore is larger than a length of the sealing member, and the a depth of the other counterbore is smaller than the length of the sealing member, and such that circumferential positions of the counterbores of the adjoining nuts face each other when a desired preload is exerted.

Abstract: In a ball screw apparatus according to the present invention, a ball guide path 19 for guiding a ball 15 scooped up in a tangential direction of a ball center track circle to a ball return path 17 is formed between a ball guide face 182 of a ball circulating member 18 and a ball guide path forming face 20 that is provided at a nut 12. Accordingly, it is possible to provide a ball screw apparatus capable of scooping up a ball in a tangential direction of a ball center track circle to circulate without reducing a diameter of the ball even when a groove interval of a ball screw groove is narrow or when the ball screw groove is a multistreak screw groove.

Abstract: A ball screw apparatus is provided which is less likely to increase dynamic friction torque even when a nut is contracted by cooling, and in which cooling effect is made as high as possible and which does not invite excessive machining efficiency droop and increase in pressure loss. The ball screw apparatus includes a screw shaft, a nut screwed with the screw shaft via a plurality of balls, and a cooling section cooling the nut. The plurality of balls to which preload is applied in a two-point contact state, with a preload direction as a tensile direction, are disposed between a screw groove of the screw shaft and a screw groove of the nut. Or, a ratio of the axial length L of the through hole axially formed in the nut and the diameter D of the through hole axially formed in the nut is given by an equation “10?L/D?60”.

Abstract: To provide a ball screw device capable of improving operability and productivity. In a ball screw device 1 including a screw shaft 4 having a helical screw shaft-side ball rolling groove formed on an outer peripheral surface thereof, a nut 2 having a nut-side ball rolling groove, opposed to the screw shaft-side ball rolling groove, formed on an inner peripheral surface thereof, and a plurality of balls loaded into the load rolling path formed between both of the ball rolling grooves, and the nut 2 has an end deflector that picks up the balls moving in the load rolling path from one end of the end deflector in a tangential direction of the screw shaft and returns the picked-up balls from the other end thereof to the load rolling path, nuts 2a and 2b are connected to each other in an axial direction of a screw shaft 4 with their opposed end surfaces come into contact with each other.

Abstract: A ball screw device has a screw shaft which has a shaft rolling groove in a spiral shape formed on an outer surface of the screw shaft, a nut which has a nut rolling groove formed on an inner surface of the nut and opposed to the shaft rolling groove, wherein the screw shaft is to be screwed in the nut so that the shaft rolling groove and the nut rolling groove are faced through a plurality of rolling balls, and a lubrication ring which is made of a lubricant-including material, comes in slide contact with the screw shaft, and is arranged in an end portion of the nut, wherein a non-contact portion, which does not come in slide contact with the screw shaft, is formed on the slide contact surface of the lubrication ring.

Abstract: A rolling screw device capable of suppressing the rather early occurrence of damage such as cracking on the tongue of an end deflector, wherein the tip part (20a) of the tongue (20) hit by a ball (13) as a rolling element is chamfered in arc shape to increase the contact area of the tip part (20a) of the tongue (20) with the ball (13).

Abstract: A ball screw apparatus which can suppress retaining pieces from contacting a wall of a ball rolling path or ball circulating path, and suppress the retaining pieces between the balls from falling down, so that such a ball screw apparatus can be improved in noise reduction, operability and endurance. The retaining piece is rounded at an edge portion opposite to the ball, such that a radius of curvature of the edge portion is defined to be 0.05 mm to 1 mm, and the outer diameter of the retaining piece is in a range of 0.60 times or more to 0.85 times or less of the diameter of the ball.

Abstract: A ball screw device has a screw shaft which has a shaft rolling groove in a spiral shape formed on an outer surface of the screw shaft, a nut which has a nut rolling groove formed on an inner surface of the nut and opposed to the shaft rolling groove, wherein the screw shaft is to be screwed in the nut so that the shaft rolling groove and the nut rolling groove are faced through a plurality of rolling balls, and a lubrication ring which is made of a lubricant-including material, comes in slide contact with the screw shaft, and is arranged in an end portion of the nut, wherein a non-contact portion, which does not come in slide contact with the screw shaft, is formed on the slide contact surface of the lubrication ring.

Abstract: In a ball screw apparatus according to the present invention, a ball guide path 19 for guiding a ball 15 scooped up in a tangential direction of a ball center track circle to a ball return path 17 is formed between a ball guide face 182 of a ball circulating member 18 and a ball guide path forming face 20 that is provided at a nut 12. Accordingly, it is possible to provide a ball screw apparatus capable of scooping up a ball in a tangential direction of a ball center track circle to circulate without reducing a diameter of the ball even when a groove interval of a ball screw groove is narrow or when the ball screw groove is a multistreak screw groove.

Abstract: The contact angle ? of ball 15 with respect to ball screw grooves 13, 14 is predetermined to a range of from not smaller than 35° to not greater than 45°. In this arrangement, the contact ellipsoid 15a of ball 15 can be prevented from running onto the beveled surface 18a of land area even when a thrust load acts on screw shaft 11 or nut 12. Accordingly, it is possible to provide a ball screw device which is not subject to easy generation of exfoliation due to hydrogen embrittlement caused by metal contact accompanying sudden rise of pressure on the contact area of ball screw groove with ball.

Abstract: The invention is to offer a ball screw apparatus which can suppress retaining pieces from contacting a wall of a ball rolling path or ball circulating path, and suppress the retaining pieces between the balls from falling down, so that such a ball screw apparatus can be offered which enables to more improve low noises, operationability and endurance. The holding piece is rounded at an edge portion opposite to the ball, such that a radius of curvature of the edge portion is defined to be 1 mm or less, and the outer diameter of the retaining piece is determined to range 0.60 times or more to 0.85 times or less of the diameter of the ball.