Tapered roller screw

Abstract

The present invention discloses a tapered roller screw pair, comprising a screw shaft, a screw nut, a tapered roller, and a tapered roller deflector. Both the screw shaft and the screw nut have helical teeth, and the helical teeth of the screw shaft and the screw nut are arranged in a cross manner in the axial direction. The side surfaces of the helical teeth of the screw shaft and the screw nut are both tapered roller raceway surfaces. A tapered roller channel is formed on both sides of the helical teeth of the screw nut, respectively, allowing the ratio of the length and radial dimension of the tapered roller to be greater than 1, and there is line contact between the tapered roller and the raceway surface. The tapered roller deflectors located at both ends of the helical teeth of the screw nut form a tapered roller reverse channel at both ends of the helical teeth of the screw nut, respectively. The tapered roller channels located on both sides of the helical teeth and the tapered roller reverse channels located at both ends of the helical teeth of the screw nut jointly form a complete tapered roller circulation channel. In a tapered roller circulation channel, a plurality of tapered rollers are arranged to form a complete tapered roller circulation chain.

Description

Technical Field

[0001] The invention belongs to the technical field of mechanical transmission, and in particular relates to a tapered roller screw pair using tapered rollers as rolling bodies. Background Art

[0002] The ball screw pair of the prior art is a rolling screw pair with balls as rolling bodies. In the ball screw pair, there are multiple balls between the spiral groove of the screw shaft and the screw nut to bear and transfer the load. When the screw shaft or the screw nut rotates, the balls roll along the spiral track in the spiral groove with load. Compared with the sliding screw pair in which the screw shaft and the screw nut are in sliding contact, the ball screw pair has the characteristic of low friction, so the ball screw pair is widely used in the fields of machine tools. However, since the balls of the ball screw pair are in point contact with the spiral groove, the contact area is very small and the contact stress is large, so it cannot withstand large loads.

[0003] In order to increase the allowable load of the rolling screw pair, the following patent documents are disclosed: 1. The invention name is "Roller Screw", the application date is September 2, 2004, and the authorization announcement number is CN 100432492C. 2. "Roller Screw", the application date is March 2, 2006, and the authorization announcement number is CN 100529472C. 3. "Roller Screw", the application date is October 29, 2008, and the authorization announcement number is CN 101903686B. The above three patent documents respectively disclose the technical solution of using rollers instead of balls as the rolling elements of the screw pair. In this roller screw pair, the outer cylindrical surface of the screw shaft has a spiral groove with a V-shaped cross section, and the inner cylindrical surface of the nut also has a spiral groove with a V-shaped cross section. The V-shaped groove of the screw shaft and the V-shaped groove of the nut face each other to form a roller channel with a quadrilateral cross section. In the channel, multiple rollers are arranged in parallel or staggered to bear and transmit axial loads. Because the contact between the roller and the spiral groove is line contact, this type of roller screw pair can withstand greater loads than a ball screw pair. However, the roller screw pairs proposed in Patent Documents 1 to 3 have the following problems: (1) The outer cylindrical surface of the roller is cylindrical. According to the relationship between motion and geometry, there must be significant slip between the roller and the raceway surface. This is because the closer the point on the outer cylindrical surface of the roller is to the axis of the screw, the smaller the linear velocity. If the roller is in pure rolling on the raceway surface, the linear velocity of each point on the outer cylindrical surface of the roller is equal. Therefore, there must be relative slip between the roller and the raceway surface, and the relative slip gradually increases with the decrease of the spiral motion radius of the roller; (2) The cross-sectional shape of the roller channel severely limits the ratio of the length to the radial dimension of the roller. For example, Patent Document 1 requires that the ratio of the length to the diameter of the cylindrical roller be less than 1. This is because in a roller channel with a quadrilateral cross-section formed by the V-groove of the screw shaft and the V-groove of the nut, if it contains rollers with staggered positions, the ratio of the length to the diameter of the roller must be less than 1. Otherwise, the roller The two ends will interfere with the inner wall of the channel, and because the load-bearing capacity of the roller is related to its length, the load-bearing capacity of the roller is limited; (3) In Patent Document 2, in order to make the roller move smoothly on the spiral raceway with a lead, it is required that the extension line of the roller's rotation axis always substantially passes through the center line of the screw shaft, which greatly increases the difficulty of implementation and lacks necessity, because even if the roller's rotation axis does not pass through the center line of the screw shaft, the roller can move smoothly on the spiral raceway with a lead; (4) Although Patent Document 2 proposes the idea of ​​using tapered rollers as rolling elements of the screw pair, the roller screw technical solution mentioned in the document is difficult to implement. This is because in the document, the spiral motion channel of the roller is formed by the V-shaped spiral grooves of the screw shaft and the nut in a face-to-face manner, and it is difficult to set tapered rollers with staggered positions in one channel. At the same time, the ratio of the length of the tapered roller to the radial dimension is limited. Summary of the invention

[0004] The purpose of the present invention is to provide a tapered roller screw pair with tapered rollers as rolling bodies between the screw shaft and the screw nut. The present invention can achieve: the contact between the rolling body and the screw shaft and the screw nut is line contact, allowing the ratio of the length and radial dimension of the rolling body to be greater than 1, which can increase the allowable load of the screw; there is no significant relative slip between the rolling body and the raceway surface, which can reduce friction; the screw can transmit bidirectional axial loads in opposite directions; the rolling body return process is smooth and easy to achieve.

[0005] The technical solution of the present invention to solve the technical problem is:

[0006] A tapered roller screw pair includes a screw shaft, a screw nut, tapered rollers, and a tapered roller reverser. The screw shaft has spiral teeth on its outer cylindrical surface, and the screw nut has spiral teeth on its inner cylindrical surface. The spiral teeth of the screw shaft and the spiral teeth of the screw nut are arranged in a cross manner in the axial direction, that is, the spiral teeth of the screw shaft are located between the tooth grooves of the spiral teeth of the screw nut, and the spiral teeth of the screw nut are located between the tooth grooves of the spiral teeth of the screw shaft; a tapered roller channel 1 is formed between one side of the spiral teeth of the screw shaft and the side of the spiral teeth of the screw nut adjacent thereto, and a tapered roller channel 2 is formed between the other side of the spiral teeth of the screw shaft and the side of the spiral teeth of the screw nut adjacent thereto; a plurality of tapered rollers are located in the channel between the spiral teeth of the screw shaft and the spiral teeth of the nut; both side surfaces of the spiral teeth of the screw shaft and the spiral teeth of the screw nut are the raceway surfaces of the tapered rollers, and the contact between the tapered rollers and the raceway surfaces is It is line contact; the two ends of the spiral teeth of the screw nut are respectively provided with a tapered roller deflector, and the tapered roller deflector forms a tapered roller reverse channel at the two ends of the spiral teeth of the screw nut, respectively, which are recorded as tapered roller reverse channel three and tapered roller reverse channel four. The tapered roller is guided from any side channel of the spiral teeth of the nut to the other side channel through the tapered roller deflector, that is, from the tapered roller channel one to the tapered roller channel two, or from the tapered roller channel two to the tapered roller channel one; the tapered roller reverse channel three, the tapered roller reverse channel four, the tapered roller channel one and the tapered roller channel two together form a complete tapered roller circulation channel, in one of the tapered roller circulation channels, a plurality of tapered rollers are arranged to form a complete tapered roller circulation chain.

[0007] The contact angles of the tapered rollers in the tapered roller channel one and the tapered roller channel two are opposite in direction when transmitting axial loads; the tapered roller channel one and the tapered roller channel two can be either load-carrying channels or load-free return channels of the tapered rollers; when the tapered roller screw pair is subjected to axial loads in any direction, one channel of the tapered rollers in the tapered roller channel one and the tapered roller channel two through which the tapered rollers bear the axial load serves as the load-carrying channel of the tapered rollers, and the other channel simultaneously serves as the load-free return channel of the tapered rollers; when the axial load is reversed, the original tapered roller load-carrying channel becomes the tapered roller load-free return channel, and at the same time, the original tapered roller load-free return channel becomes the tapered roller load-carrying channel; the maximum axial clearance between the tapered rollers and the spiral raceway surface of the screw shaft or the spiral raceway surface of the screw nut can allow the tapered rollers to move smoothly along the spiral channel trajectory in the load-free return channel.

[0008] The outer edges of the spiral raceway surfaces of the tapered rollers on both sides of the spiral teeth of the screw shaft are provided with protruding ribs, and the inner side surfaces of the ribs are in contact with the large end surfaces of the tapered rollers.

[0009] The ratio of the length of the tapered roller to the large end diameter is allowed to be greater than 1; the large end face of the tapered roller is a convex spherical surface, the radius of which is smaller than the inner side face of the outer edge rib of the screw shaft and the radius of curvature in any direction; the generatrix of the outer conical surface of the tapered roller is a straight line, or a circular arc or a conical arc convex outward.

[0010] In the tapered roller channel one and the tapered roller channel two, when the tapered roller is subjected to an axial load, without considering the contact deformation between the tapered roller and the raceway surface, the movement of the tapered roller relative to the screw shaft and the spiral raceway surface of the screw nut is pure rolling, and the contact lines between the tapered roller and the two spiral raceway surfaces are both located in the normal plane of the spiral motion trajectory of the tapered roller; in the tapered roller channel one and the tapered roller channel two, the small end faces of the tapered rollers are all facing the inner side of the screw shaft; in the tapered roller channel one and the tapered roller channel two, when the tapered roller transmits an axial load, the extension line of the tapered roller's rotation axis does not necessarily intersect with the center line of the screw shaft, and only when the tapered roller's rotation axis is perpendicular to the center line of the screw shaft, the extension line of the tapered roller's rotation axis intersects with the center line of the screw shaft; in the tapered roller channel one and the tapered roller channel two, when the tapered roller When the tapered roller transmits axial load, the motion trajectory of any point on the tapered roller's rotation axis and its extension line is a spiral line. Only when the extension line of the tapered roller's rotation axis intersects with the center line of the screw shaft, the motion trajectory of the intersection is a straight line coinciding with the center line of the screw shaft; in the tapered roller channel 1 and the tapered roller channel 2, the tapered roller intersects with the extension line of the contact line of the screw shaft and the screw nut when transmitting the axial load at a point, which is recorded as point J. The intersection is located on the extension line of the tapered roller's rotation axis, but not necessarily on the center line of the screw shaft and its extension line. Only when the tapered roller's rotation axis is perpendicular to the center line of the screw shaft, and the distance between point J and any point on the tapered roller's rotation axis is equal to the distance between the arbitrary point and the center line of the screw shaft, the intersection J is located on the center line of the screw shaft, at which time the motion trajectory of the intersection J is a straight line coinciding with the center line of the screw shaft.

[0011] Both ends of the helical teeth of the lead screw nut have transition curved surfaces.

[0012] The action surface on the tapered roller reverser that causes the tapered roller to perform reverse motion is located between the tooth grooves of the helical teeth of the screw shaft and faces the two ends of the helical teeth of the screw nut; the action surface on the tapered roller reverser that causes the tapered roller to perform reverse motion and the side surface in contact with the large end surface of the tapered roller are both concave surfaces, and the shapes of these two concave surfaces can keep the movement of the tapered roller stable when entering and exiting the tapered roller reverse channel three and the tapered roller reverse channel four; when the tapered roller reverser has one tapered roller reverse action surface, it is called a single reverse surface tapered roller reverser, and when it has two tapered roller reverse action surfaces, it is called a double reverse surface tapered roller reverser.

[0013] The upper end face and the lower end face of the tapered roller deflector located in the spiral tooth groove of the screw shaft are both spiral surfaces, and there is a geometric gap between the two spiral end faces and the adjacent spiral raceway surfaces of the screw shaft, and the roots of the two spiral end faces of the tapered roller deflector are both provided with grooves, and there is a geometric gap between the inner surface of the groove and the outer edge rib of the spiral tooth of the screw shaft.

[0014] The tapered roller screw pair may not only have one complete tapered roller circulating chain, but may also have two or more complete tapered roller circulating chains. When the tapered roller screw pair has two or more complete tapered roller circulating chains, the helical teeth of the screw nut are divided into two or more discontinuous sections along the spiral direction, and both ends of the helical teeth of each section of the screw nut have transition surfaces, and there is a gap between any two adjacent end faces of the helical teeth, and there is a double reverse surface tapered roller deflector in the gap, and both sides of the double reverse surface tapered roller deflector have action surfaces that make the tapered rollers move in the opposite direction, and the tapered roller channel one and the tapered roller channel two are divided into two or more sections by the double reverse surface tapered roller deflector, and each section of the helical teeth of the screw nut is respectively connected to the tapered roller deflectors at both ends. A complete tapered roller circulation channel is formed, and multiple tapered rollers can form a tapered roller circulation chain in each tapered roller circulation channel; the working surface on the double-reverse-face tapered roller deflector that contacts the outer tapered surface of the tapered roller and the working surface that contacts the large end surface of the tapered roller are both concave surfaces; the upper end surface and the lower end surface of the double-reverse-face tapered roller deflector located in the spiral tooth groove of the screw shaft are both spiral surfaces, and there are geometric gaps between these two spiral end surfaces and the adjacent spiral raceway surfaces of the screw shaft, and there are grooves at the roots of these two spiral end surfaces, and there are also geometric gaps between the inner surface of the groove and the outer edge rib of the spiral tooth of the screw shaft.

[0015] When the generatrix of the outer conical surface of the tapered roller is an outwardly convex arc or conical arc, the contour of the spiral raceway surface of the screw shaft in the normal section of the spiral tooth of the screw shaft is a straight line, or a circular arc or conical arc bent inwardly toward the tooth, and the contour of the spiral raceway surface of the screw nut in the normal section of the spiral tooth of the screw nut is also a straight line, or a circular arc or conical arc bent inwardly toward the tooth.

[0016] In the tapered roller circulation channel of the tapered roller screw pair, any two adjacent tapered rollers may be in direct contact or a separator may be provided between them. When a separator is provided between two adjacent tapered rollers, the two tapered rollers are respectively located on both sides of the separator and transmit thrust or resistance by contacting the two side surfaces of the separator; the two side surfaces of the tapered roller separator in contact with the tapered roller are both concave conical surfaces, and the small end radius and the large end radius of the two tapered side surfaces are respectively larger than the small end radius and the large end radius of the tapered roller.

[0017] The tapered roller reverser of the tapered roller screw pair can also adopt a floating structure, that is, the reverse action surface of the tapered roller reverser can float along the spiral groove of the screw shaft under the contact load of the tapered roller, and has stiffness and damping that meet the use requirements in the floating direction; when the floating tapered roller reverser has only one floating tapered roller reverse surface, it is called a single reverse surface floating tapered roller reverser, and when it has two floating tapered roller reverse surfaces, it is called a double reverse surface floating tapered roller reverser; when the tapered roller screw pair adopts a floating tapered roller reverser, the single reverse surface tapered roller reverser and the double reverse surface tapered roller reverser respectively adopt a single reverse surface floating tapered roller reverser and a double reverse surface floating tapered roller reverser.

[0018] The single-reverse floating tapered roller reverser is mainly composed of a back plate, a floating block, an adjusting block, a fixed block, a plate spring, a wedge key and a cover plate; the inner side of the back plate is provided with a guide groove, the guide track of the guide groove is a spiral line, and its lead is the same as the lead of the spiral groove of the screw shaft, the floating block can move along the guide groove, and the adjusting block can also move along the guide groove; the fixed block is fixed on the screw nut, the wedge key is located between the fixed block and the adjusting block, and the plate spring is located between the adjusting block and the floating block. The position of the adjusting block in the guide groove of the back plate can be changed by adjusting the position of the wedge key, thereby changing the distance between the adjusting block and the floating block and the deformation of the leaf spring. After being deformed by pressure, the leaf spring applies a preload to the floating block, so that the floating block can float along the guide groove of the back plate when impacted by the tapered roller. The upper end face and lower end face of the floating block and the upper end face and lower end face of the adjusting block are all spiral surfaces, and their lead is the same as the lead of the spiral groove of the screw shaft. The cover plate contacts the large end face of the wedge key, and the position of the wedge key is adjusted through the cover plate.

[0019] The double reverse surface floating tapered roller reverser is mainly composed of a back plate, a floating block 1, a floating block 2, a wedge key, a plate spring, a pressure plate and an adjusting gasket; the inner side surface of the back plate has a guide groove, the guide trajectory of the guide groove is a spiral line, and its lead is the same as the lead of the spiral groove of the screw shaft; the floating block 1 and the floating block 2 can move along the back plate guide groove when impacted by the tapered roller; the tapered roller reverse action surfaces on the floating block 1 and the floating block 2 are respectively located on both sides of the double reverse surface floating tapered roller reverser, and are respectively facing the tapered roller channels on both sides of the double reverse surface floating tapered roller reverser; the plate spring and the wedge key are both located Between the floating block one and the floating block two, the plate spring applies a preload to the floating block after being deformed by compression, and the deformation amount of the plate spring and the size of the preload are changed by the wedge key; the middle part of the back plate is provided with a through hole, and the wedge-shaped part of the wedge key and the elastic action part of the plate spring both penetrate into the inner side of the back plate from the through hole in the middle part of the back plate; the adjusting gasket is located between the plate spring and the wedge key, and the position of the wedge key relative to the plate spring is changed by changing the thickness of the adjusting gasket, thereby adjusting the deformation amount of the variable plate spring and the size of the preload; the wedge key, the plate spring and the adjusting gasket are all fixed on the back plate of the double reverse surface floating tapered roller reverser.

[0020] The screw shaft and the tapered roller may be not only solid structures but also hollow structures.

[0021] Beneficial effects of the present invention:

[0022] 1. The present invention forms two tapered roller channels on both sides of the spiral teeth of the screw shaft and the screw nut by assembling the spiral teeth of the screw shaft and the screw nut in a cross manner in the axial direction of the tapered roller screw pair, and a plurality of tapered rollers are arranged in the two tapered roller channels to bear and transmit the load. By respectively arranging tapered roller reversers at the two end extensions of the spiral teeth of the screw nut, the tapered roller channels on both sides of the spiral teeth of the screw nut can be connected at the two ends of the spiral teeth of the screw nut, thereby forming a complete tapered roller circulation channel. In a tapered roller circulation channel, a plurality of tapered rollers are arranged to form a tapered roller circulation chain. Because the contact angles of the tapered rollers located in the channels on both sides of the screw shaft and the spiral teeth of the screw are opposite when transmitting axial loads, they can withstand axial loads in opposite directions. When the tapered roller screw pair is subjected to axial load, one of the two channels located on both sides of the screw shaft and the screw nut helical teeth serves as the tapered roller load travel channel, and the other serves as the tapered roller no-load return channel. When the axial load is reversed, the original tapered roller load travel channel becomes the tapered roller no-load return channel, and at the same time, the original tapered roller no-load return channel becomes the tapered roller load travel channel. Therefore, these two channels can be both the tapered roller load travel channel and the tapered roller no-load return channel. When any one of them serves as the tapered roller load travel channel, the other serves as the tapered roller no-load return channel at the same time, so there is no need to design a separate tapered roller return channel. The maximum axial clearance between the tapered roller and the screw shaft or nut allows the tapered roller to move smoothly in the no-load return channel, so that the tapered roller can smoothly return to the starting end of its load travel channel.

[0023] 2. The tapered roller reverse channel of the tapered roller screw pair of the present invention is located at both ends of the helical teeth of the screw nut, and the load travel channel and the no-load return channel of the tapered roller are respectively located on both sides of the helical teeth of the screw nut, so the tapered roller does not need to cross the top of the helical teeth of the screw shaft, nor does it need to leave the tooth groove of the helical teeth of the screw shaft during the reverse and return process.

[0024] 3. The outer edge of the spiral raceway surface of the screw shaft of the present invention has a rib structure, and the inner side surfaces of the two ribs are in contact with the large end surface of the tapered roller. This allows the ribs to bear part of the axial load transmitted by the tapered roller and can prevent the tapered roller from sliding toward the outside of the spiral raceway surface of the screw shaft under the action of the axial load.

[0025] 4. The ratio of the length L of the tapered roller of the tapered roller screw pair of the present invention to the large end diameter is allowed to be greater than 1, so that a single tapered roller can have a larger contact area with the spiral raceway surface of the screw shaft and the screw nut, thereby improving the load-bearing capacity of a single tapered roller; the large end surface of the tapered roller is a convex spherical surface, and the curvature radius of the convex spherical surface is smaller than the curvature radius of any direction of the inner side surface of the outer edge rib of the screw shaft, so that the contact between the large end surface of the tapered roller and the inner side surface of the outer edge rib of the spiral raceway surface of the screw shaft can be single-point contact, thereby avoiding geometric interference between the large end surface of the tapered roller and the inner side surface of the outer edge rib of the spiral raceway surface of the screw shaft. The generatrix of the outer conical surface of the tapered roller of the tapered roller screw pair can be a straight line, or a circular arc or a conical arc convex outward. When the generatrix of the outer conical surface of the tapered roller is a straight line, the contact area between a single tapered roller and the screw shaft and the screw nut raceway surface is the largest under the same size conditions, thereby increasing the load-bearing capacity of a single tapered roller; when the generatrix of the outer conical surface of the tapered roller is an outwardly convex arc or conical arc, the edge effect of the contact stress distribution between the tapered roller and the spiral raceway surface can be reduced or avoided, and at the same time it is beneficial to increase the movement flexibility of the tapered roller and reduce the friction between the tapered roller and the screw shaft and the screw nut raceway surface.

[0026] 5. When the tapered roller screw pair of the present invention is subjected to axial load, when the contact deformation between the tapered roller and the screw shaft and the spiral raceway surface of the screw nut is ignored, the movement of the tapered roller relative to the screw shaft and the spiral raceway surface of the screw nut in the load travel channel is pure rolling, thereby reducing the sliding friction between the tapered roller and the raceway surface.

[0027] 6. Both ends of the helical teeth of the lead screw nut of the present invention have transition surfaces, which can reduce the load change rate of the tapered roller when entering and exiting the tapered roller reverse channel, so that the tapered roller gradually transitions from a loaded state to a no-load state, or from a no-load state to a loaded state, thereby improving the stability of the tapered roller during the reverse movement and reducing the impact of the tapered roller caused by too rapid changes in movement direction and load.

[0028] 7. The action curved surface on the tapered roller deflector of the present invention that causes the tapered roller to reverse is located at the extension of the two ends of the screw nut helical teeth, and is located between the tooth grooves of the screw shaft helical teeth, so that the tapered roller can reverse from the load travel channel to the unloaded return channel at the two ends of the screw nut helical teeth, or reverse from the unloaded return channel to the load travel channel. The side and the side of the tapered roller deflector that contact the tapered roller are both concave curved surfaces, which function to change the movement direction of the tapered roller in the tapered roller reverse channel three and the tapered roller reverse channel four, and adjust the posture of the tapered roller during the reverse movement, so that the movement posture of the tapered roller near the ports of the tapered roller channel one and the tapered roller channel two in the reverse channel is close to the movement posture of the tapered roller near the ports in the tapered roller channel one and the tapered roller channel two, so that the tapered roller can smoothly reverse from the tapered roller channel one to the tapered roller channel two, or reverse from the tapered roller channel two to the tapered roller channel one.

[0029] 8. The upper and lower end faces of the tapered roller deflector of the present invention located in the spiral tooth grooves of the screw shaft are both spiral surfaces, and there are geometric gaps between the two spiral end faces and the adjacent spiral raceway surfaces of the screw shaft, and the roots of the two spiral end faces have a groove structure, and there are geometric gaps between the inner surface of the groove and the outer edge rib of the spiral teeth of the screw shaft, thereby avoiding geometric interference between the tapered roller deflector and the spiral teeth of the screw shaft.

[0030] 9. The tapered roller screw pair of the present invention may include two or more complete tapered roller circulation channels. When the tapered roller screw pair has two or more tapered roller circulation chains, the screw nut helical teeth are divided into two or more sections along the spiral direction, and there is a gap between any two adjacent sections of the screw nut helical teeth, and a double reverse surface tapered roller deflector is arranged in the gap. Both sides of the double reverse surface tapered roller deflector have concave curved surfaces for reversing the tapered rollers, thereby forming a tapered roller reversing channel on both sides of the double reverse surface tapered roller deflector, and at the same time, the double reverse surface tapered roller deflector divides the tapered roller channel 1 and the tapered roller channel 2 into two ends or multiple sections, thereby forming a complete tapered roller circulation channel on both sides of the double reverse surface tapered roller deflector. Because the tapered rollers in each tapered roller circulation channel form a tapered roller circulation chain, the tapered roller screw pair has two or more tapered roller circulation chains. When the tapered roller screw pair has two or more tapered roller circulating chains, the length of a single tapered roller circulating channel can be shortened, and the number of tapered rollers in a single tapered roller circulating chain can be reduced, thereby facilitating the reduction of the travel resistance of the tapered rollers in the circulating channel.

[0031] 10. When the generatrix of the outer conical surface of the tapered roller of the tapered roller screw pair of the present invention is an outwardly convex arc or conical arc, and the contour of the spiral raceway surface of the screw shaft in the normal section of the spiral teeth of the screw shaft is a circular arc or conical arc bent inwardly toward the teeth, and the contour of the spiral raceway surface of the screw nut in the normal section of the spiral teeth of the screw nut is a circular arc or conical arc bent inwardly toward the teeth, the tapered roller can have a strong flexibility of movement in the circulation channel while having a large contact area and load-bearing capacity with the screw shaft and the spiral raceway surface of the screw nut.

[0032] 11. When there is a separator between any two adjacent tapered rollers of the tapered roller screw pair of the present invention, direct contact between the tapered rollers can be avoided, which is beneficial to reducing friction; the two side surfaces of the tapered roller separator are both concave conical surfaces, and the small end radius and large end radius of the two conical side surfaces are respectively larger than the small end radius and large end radius of the tapered roller, thereby avoiding geometric interference between the tapered roller and its separator.

[0033] 12. When the tapered roller screw pair of the present invention adopts the floating tapered roller reverser, the impact and vibration of the tapered roller on the reverser during the reverse process can be reduced.

[0034] 13. The floating block of the single-reverse surface floating tapered roller deflector of the present invention can move in the guide groove on the inner side of the back plate, and there is a plate spring support between the floating block and the adjustment block, and the adjustment block is relatively fixed under normal circumstances, so the floating block can float along the direction of the guide groove when impacted by the tapered roller, thereby reducing the vibration caused by the impact; because the guide trajectory of the back plate guide groove is a spiral line, and its lead is the same as the lead of the spiral groove of the screw shaft, so the floating trajectory of the floating block is also a spiral line, and its lead is also the same as the lead of the spiral groove of the screw shaft, and because the upper end face and the lower end face of the floating block are both spiral surfaces, and the leads of these two spiral surfaces are the same as the lead of the spiral groove of the screw shaft, the floating block will not have geometric interference with the spiral tooth surface of the screw shaft during the floating process; the position of the adjustment block in the back plate guide groove can be changed by the wedge key, so that the distance between the floating block and the adjustment block and the compression deformation of the plate spring can be adjusted, so that the preload force of the floating block can be adjusted. In addition, a damping element may be arranged between the floating block and the adjusting block of the single-reverse-surface floating tapered roller deflector, so as to further reduce the vibration caused by the impact of the tapered roller.

[0035] 14. The two floating blocks of the double reverse surface floating tapered roller deflector of the present invention can move along the guide groove on the inner side of the back plate. Because there is a plate spring support between the two floating blocks, the floating blocks can float along the guide groove on the inner side of the back plate when impacted by the tapered roller, thereby reducing the vibration caused by the impact of the tapered roller; because the guide track of the guide groove is a spiral line, and its lead is the same as the lead of the spiral groove of the screw shaft, the floating track of the two floating blocks is also a spiral line, and its lead is also the same as the lead of the spiral groove of the screw shaft. Because the upper end face and the lower end face of the floating block are both spiral surfaces, and its lead is the same as the lead of the spiral groove of the screw shaft, the two floating blocks will not have geometric interference with the screw shaft during the floating process; the pre-deformation of the plate spring can be changed by the wedge key, so that the pre-tightening force of the two floating blocks can be adjusted. In addition, a damping element can be set between the two floating blocks of the double reverse surface floating tapered roller deflector, which can further reduce the vibration caused by the impact of the tapered roller.

[0036] 15. When the screw shaft and the tapered rollers of the tapered roller screw pair of the present invention are hollow structures, it is not only beneficial to reduce the weight of the tapered roller screw pair, but also beneficial to reduce the centrifugal force of the tapered rollers and the impact force of the tapered rollers on the reverser. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 It is a partial structural sectional view of the tapered roller screw pair provided by the present invention.

[0038] Figure 2 It is a schematic diagram of a single tapered roller circulating chain of the tapered roller screw pair provided by the present invention.

[0039] Figure 3 It is a structural diagram of the screw shaft of the tapered roller screw pair provided by the present invention.

[0040] Figure 4 It is a cross-sectional view of the helical teeth of the screw shaft of the tapered roller screw pair provided by the present invention.

[0041] Figure 5 It is a partial structural sectional view of the screw nut of the tapered roller screw pair provided by the present invention.

[0042] Figure 6 It is a cross-sectional view of the assembly of the screw shaft and the screw nut of the tapered roller screw pair provided by the present invention.

[0043] Figure 7a Schematic diagram of the tapered roller structure with the outer cone surface generatrix being a straight line.

[0044] Figure 7b It is a schematic diagram of the tapered roller structure in which the generatrix of the outer cone surface is a circular arc or a conical arc.

[0045] Figure 8 It is a cross-sectional view of the assembly of the screw shaft, screw nut and tapered roller of the tapered roller screw pair provided by the present invention.

[0046] Fig. 9 It is a schematic diagram of the assembly of the screw shaft and the tapered rollers of the tapered roller screw pair provided by the present invention.

[0047] Fig.10 The cross-sectional view of the screw nut of the tapered roller screw pair provided by the present invention is Figure 1 .

[0048] Fig.11 The cross-sectional view of the screw nut of the tapered roller screw pair provided by the present invention is Figure 2 .

[0049] Fig.12 The invention provides a single reverse surface tapered roller reverser structure of a tapered roller screw pair. Figure 1 .

[0050] Fig.13 The invention provides a single reverse surface tapered roller reverser structure of a tapered roller screw pair. Figure 2 .

[0051] Fig.14 The invention provides a cross-sectional view of the assembly of the screw nut of the tapered roller screw pair and two single-reverse tapered roller reversers. Figure 1 .

[0052] Fig.15 The invention provides a cross-sectional view of the assembly of the screw nut of the tapered roller screw pair and two single-reverse tapered roller reversers. Figure 2 .

[0053] Fig.16 The invention provides a cross-sectional view of the assembly of a screw nut, a plurality of tapered rollers and two single-reverse-face tapered roller reversers of a tapered roller screw pair. Figure 1 .

[0054] Fig.17 The invention provides a cross-sectional view of the assembly of a screw nut, a plurality of tapered rollers and two single-reverse-face tapered roller reversers of a tapered roller screw pair. Figure 2 .

[0055] Fig.18 It is a schematic diagram of the posture of the tapered roller of the tapered roller screw pair provided by the present invention when entering and exiting the tapered roller reverse channel.

[0056] Fig.19 It is a cross-sectional view of the positional relationship between the screw shaft of the tapered roller screw pair and the single-reverse-face tapered roller reverser provided by the present invention.

[0057] Fig. 20 It is a schematic diagram of the axial clearance between the tapered rollers of the tapered roller screw pair provided by the present invention and the spiral raceway surface of the screw shaft or the spiral raceway surface of the screw nut.

[0058] Fig.21a The motion posture of the tapered roller of the tapered roller screw pair provided by the present invention during the load movement process is shown in FIG. Figure 1 .

[0059] Figure 21b The motion posture of the tapered roller of the tapered roller screw pair provided by the present invention during the load movement process is shown in FIG. Figure 2 .

[0060] Fig. 22 It is a segmented structural diagram of the helical teeth of the screw nut of the tapered roller screw pair provided by the present invention when the screw pair has two tapered roller circulation channels.

[0061] Fig.23 The structure of the double reverse surface tapered roller reverser provided by the present invention is Figure 1 .

[0062] Fig.24 The structure of the double reverse surface tapered roller reverser provided by the present invention is Figure 2 .

[0063] Fig.25 The structure of the double reverse surface tapered roller reverser provided by the present invention is Figure 3 .

[0064] Fig.26 The invention discloses an assembly position relationship between the spiral teeth of the screw nut and the double-reverse-face tapered roller reverser when the tapered roller screw pair provided by the invention has two tapered roller circulation channels.

[0065] Fig. 27 The invention provides a cross-sectional view of the assembly of a screw nut, a plurality of tapered rollers and a tapered roller reverser when the tapered roller screw pair has two tapered roller circulating chains. Figure 1 .

[0066] Fig.28 The invention provides a cross-sectional view of the assembly of a screw nut, a plurality of tapered rollers and a tapered roller reverser when the tapered roller screw pair has two tapered roller circulating chains. Figure 2 .

[0067] Fig.29 It is a structural diagram of a double reverse surface tapered roller reverser installed on a lead screw nut provided by the present invention.

[0068] Fig.30 It is a schematic diagram of a partial cross-sectional structure of a screw shaft with a concave spiral tooth side surface structure provided by the present invention.

[0069] Fig.31 It is a schematic diagram of a partial cross-sectional structure of a lead screw nut with a concave spiral tooth side surface structure provided by the present invention.

[0070] Fig.32 It is a schematic diagram of the local matching relationship of the tapered roller screw pair provided by the present invention when using a tapered roller whose outer cone surface generatrix is ​​a circular arc or a conical arc, a screw shaft whose spiral tooth side surface is a concave spiral surface, and a screw nut.

[0071] Fig.33 It is a schematic diagram of a tapered roller circulating chain when the tapered roller screw pair provided by the present invention has a tapered roller separator.

[0072] Fig.34a The structure diagram of the tapered roller separator of the tapered roller screw pair provided by the present invention is Figure 1 ;

[0073] Fig.34b The structure diagram of the tapered roller separator of the tapered roller screw pair provided by the present invention is Figure 2 .

[0074] Fig.35 It is a schematic diagram of the positional relationship between any two adjacent tapered rollers and the separator when the tapered roller screw pair provided by the present invention has a tapered roller separator.

[0075] Fig.36 It is an assembly cross-sectional view of a single tapered roller circulating chain, a screw nut and a tapered roller reverser of a tapered roller screw pair provided by the present invention when the tapered roller screw pair has a tapered roller separator.

[0076] Fig.37 It is a schematic diagram of the inner structure of the single reverse surface floating tapered roller reverser provided by the present invention.

[0077] Fig.38 It is a schematic diagram of the inner structure of the single reverse surface floating tapered roller reverser provided by the present invention after the floating block is removed.

[0078] Fig.39 It is a schematic diagram of the back plate structure of the single reverse surface floating tapered roller reverser provided by the present invention.

[0079] Fig.40 The figure is a schematic diagram of the floating block structure of the single reverse surface floating tapered roller reverser provided by the present invention.

[0080] Fig.41a The schematic diagram of the adjustment block structure of the single reverse floating tapered roller reverser provided by the present invention is Figure 1 .

[0081] Fig.41bThe schematic diagram of the adjustment block structure of the single reverse floating tapered roller reverser provided by the present invention is Figure 2 .

[0082] Fig.41c The schematic diagram of the adjustment block structure of the single reverse floating tapered roller reverser provided by the present invention is Figure 3 .

[0083] Fig.42 The diagram is a schematic diagram of the plate spring structure of the single reverse surface floating tapered roller reverser provided by the present invention.

[0084] Fig.43 The utility model is a schematic diagram of the assembly relationship between the back plate, the wedge key and the adjustment block of the single reverse surface floating tapered roller reverser provided by the present invention.

[0085] Fig.44 The utility model is a schematic diagram of the assembly relationship between the back plate, the wedge key and the fixed block of the single reverse surface floating tapered roller reverser provided by the present invention.

[0086] Fig.45 The utility model is a schematic diagram of the assembly relationship between the back plate, the fixing block and the cover plate of the single reverse surface floating tapered roller reverser provided by the present invention.

[0087] Fig.46a The structure diagram of the double reverse surface floating tapered roller reverser provided by the present invention is shown in FIG. Figure 1 .

[0088] Fig.46b The structure diagram of the double reverse surface floating tapered roller reverser provided by the present invention is shown in FIG. Figure 2 .

[0089] Fig.47a The structure diagram of the back plate of the double reverse surface floating tapered roller reverser provided by the present invention is Figure 1 .

[0090] Figure 47b The structure diagram of the back plate of the double reverse surface floating tapered roller reverser provided by the present invention is Figure 2 .

[0091] Fig.48a The structure diagram of the floating block of the double reverse surface floating tapered roller reverser provided by the present invention is as follows Figure 1 .

[0092] Figure 48b The structure diagram of the floating block of the double reverse surface floating tapered roller reverser provided by the present invention is as follows Figure 2 .

[0093] Fig.49a The structure diagram of the floating block 2 of the double reverse surface floating tapered roller reverser provided by the present invention is Figure 1 .

[0094] Fig.49b The structure diagram of the floating block 2 of the double reverse surface floating tapered roller reverser provided by the present invention is Figure 2 .

[0095] Fig.50 It is a schematic diagram of the inner structure of the double-reverse-surface floating tapered roller reverser of the present invention after the two floating blocks are removed.

[0096] Fig.51 It is a schematic structural diagram of a leaf spring of a double-reverse-surface floating tapered roller reverser provided by the present invention.

[0097] Fig.52 It is a schematic structural diagram of the wedge key of the double reverse surface floating tapered roller reverser provided by the present invention.

[0098] Fig.53 The utility model is a cross-sectional schematic diagram of the assembly relationship between the back plate, the plate spring, the wedge key, the spring pressure plate and the adjustment gasket of the double reverse surface floating tapered roller reverser provided by the present invention.

[0099] Fig.54 The utility model relates to a hollow structure of a screw shaft of a tapered roller screw pair implemented by the present invention.

[0100] Fig.55a The invention provides a hollow structure of a tapered roller whose outer cone surface generatrix is ​​a straight line.

[0101] Fig.55b The invention provides a hollow structure of a tapered roller whose outer conical surface generatrix is ​​a circular arc or a conical arc.

[0102] In the drawings of the present invention, the drawings related to bolt connection, screw connection and locating pin positioning do not show the bolts, screws and locating pins used, but it does not mean that there are no bolts, screws and locating pins in the relevant assembly.

[0103] Description of reference numerals:

[0104] In the figure, 1. screw shaft; 1c. center line of the screw shaft; 11. spiral teeth of the screw shaft; 11a, 11b. spiral raceway surfaces of the screw shaft, i.e., tapered roller raceway surfaces on both sides of the spiral teeth of the screw shaft; 11a1. contour line of the spiral raceway surface 11a of the screw shaft in the axial section containing the center line 1c of the screw shaft; 11b1. contour line of the spiral raceway surface 11b of the screw shaft in the axial section containing the center line 1c of the screw shaft; 111. outer edge rib of the spiral raceway surface 11a of the screw shaft; 112. outer edge rib of the spiral raceway surface 11b of the screw shaft; 111a. inner side surface of the outer edge rib of the spiral raceway surface 11a of the screw shaft; 112a. inner side surface of the outer edge rib of the spiral raceway surface 11b of the screw shaft; 2. screw nut; 21 .Screw nut spiral teeth; 21a, 21b. Screw nut spiral raceway surface, i.e., the tapered roller raceway surfaces on both sides of the screw nut spiral teeth; 21a1, 21b1. The contour lines of the screw nut spiral raceway surfaces 21a and 21b in the axial section containing the center line of the screw nut; 21c, 21d. Transition surfaces at both ends of the screw nut spiral teeth; 22, 23, 24, 25. Threaded holes for mounting the tapered roller deflector 4 on the screw nut; 26, 27. Wedge-shaped positioning surfaces for mounting the tapered roller deflector 4 on the screw nut; 28, 29. Positioning holes for mounting the double-reverse-face tapered roller deflector 5 on the screw nut; 210, 211. Threaded holes for mounting the double-reverse-face tapered roller deflector 5 on the screw nut; 212. Window for mounting the double reverse-face tapered roller deflector 5 on the lever nut; 3. tapered roller; 3a. small end face of the tapered roller; 3a. large end face of the tapered roller; 3c. axis of rotation of the tapered roller; 3e. generatrix of the outer conical surface of the tapered roller; 31, 32. contact lines between the tapered roller and the spiral raceway surface of the screw shaft and the spiral raceway surface of the screw nut during load travel; 4. single reverse-face tapered roller deflector; 4a. action curved surface on the tapered roller deflector 4 that reverses the tapered roller; 4b, 4c. upper and lower spiral end faces of the tapered roller deflector 4 located in the spiral tooth groove of the screw shaft; 4d. concave curved surface on the tapered roller deflector 4 that contacts the large end face of the tapered roller; 4e. wedge of the tapered roller deflector 4 Positioning surface; 41, 42. Countersunk holes for screw connection on the tapered roller deflector 4; 43, 44. Grooves at the roots of the spiral end faces 4b and 4c on the tapered roller deflector 4; 5. Double reverse surface tapered roller deflector; 5a, 5b. Two-side action curved surfaces on the double reverse surface tapered roller deflector 5 that reverse the tapered roller; 5c, 5d. Upper and lower spiral end faces of the double reverse surface tapered roller deflector 5 located in the spiral tooth groove of the screw shaft; 5e, 5f. Two-side concave curved surfaces on the double reverse surface tapered roller deflector 5 that contact the large end faces of the tapered roller; 51, 52. Installation positioning holes for the double reverse surface tapered roller deflector 5; 53, 54. Threaded holes on the double reverse surface tapered roller deflector 5; 55, 56.The grooves at the root of the spiral end surface 5c and 5d on the double reverse surface tapered roller deflector 5; 6. Tapered roller separator; 6a, 6b. The conical surfaces on both sides of the tapered roller separator 6; 6c, 6d. The contour center lines of the conical surfaces on both sides of the tapered roller separator 6; 7. Single reverse surface floating tapered roller deflector; 71. The back plate of the single reverse surface floating tapered roller deflector 7; 711. The guide groove on the inner side of the back plate 71 of the single reverse surface floating tapered roller deflector; 712. The wedge-shaped keyway on the back plate 71 of the single reverse surface floating tapered roller deflector; 72. The floating block of the single reverse surface floating tapered roller deflector 7; 72a, 72b. The upper and lower end surfaces of the floating block 72 of the single reverse surface floating tapered roller deflector; 72c , 72d. floating guide surface of the floating block 72 of the single reverse surface floating tapered roller reverser; 72e. tapered roller reverse action surface on the floating block 72 of the single reverse surface floating tapered roller reverser; 73. adjustment block of the single reverse surface floating tapered roller reverser 7; 73a, 73b. upper and lower end surfaces of the adjustment block 73 of the single reverse surface floating tapered roller reverser; 73c, 73d. guide surface of the adjustment block 73 of the single reverse surface floating tapered roller reverser; 73e. wedge surface on the adjustment block of the single reverse surface floating tapered roller reverser; 731. spring positioning groove on the adjustment block 73 of the single reverse surface floating tapered roller reverser; 74. fixed block of the single reverse surface floating tapered roller reverser 7; 75. The plate spring of the roller reverser 7; 751. The elastic action part of the plate spring 75 of the single reverse floating tapered roller reverser; 752. The fixed end of the plate spring 75 of the single reverse floating tapered roller reverser; 76. The wedge key of the single reverse floating tapered roller reverser 7; 77. The cover plate of the single reverse floating tapered roller reverser 7; 8. The double reverse floating tapered roller reverser; 81. The back plate of the double reverse floating tapered roller reverser 8; 811. The guide groove on the inner side of the back plate 81 of the double reverse floating tapered roller reverser; 812. The through hole in the middle of the back plate 81 of the double reverse floating tapered roller reverser; 82, 83. The floating block of the double reverse floating tapered roller reverser 8; 82a, 83a are The upper end faces of the floating blocks 82 and 83, 82b and 83b are the lower end faces of the floating blocks 82 and 83; 82c, 82d, 83c and 83d are the floating guide faces on the floating blocks 82 and 83; 82e and 83e are the tapered roller reverse action faces on the floating blocks 82 and 83; 82f and 83f are the spring contact faces on the floating blocks 82 and 83; 84. The wedge key of the double reverse surface floating tapered roller reverser 8; 841. The wedge-shaped portion of the wedge key 84; 842. The fixed end of the wedge key 84; 85 and 86. The leaf spring of the double reverse surface floating tapered roller reverser 8; 851. The elastic action portion of the leaf spring 85; 852. The fixed end of the leaf spring 85; 87. The pressure plate of the leaf springs 85 and 86; 88.Adjustment gasket between the leaf spring and the wedge key in the double reverse surface floating tapered roller deflector 8; d1. Small end diameter of the tapered roller; d2. Large end diameter of the tapered roller; l. Length of the tapered roller; A, B. Axial load direction of the tapered roller screw pair; CH1, CH2. Tapered roller channels located on both sides of the spiral teeth of the screw shaft and the spiral teeth of the screw nut; CH3, CH4. Tapered roller reverse channels located at both ends of the spiral teeth of the screw nut; CH5, CH6. When the tapered roller screw pair has two or more tapered roller circulating chains, the tapered roller reverse channel formed by the double reverse surface tapered roller deflector 8 in the gap between the end faces of the spiral teeth of two adjacent sections of the nut; J. Intersection point of the extended line of the contact line between the tapered roller and the spiral raceway surface of the screw shaft and the screw nut during load movement; N. Normal plane of the spiral motion trajectory of the geometric center of the tapered roller; O. r .Any point on the geometric center line of the tapered roller; S1. Point O r : S2. The spiral motion trajectory of the intersection J; Δ. The maximum gap between the tapered roller and the spiral raceway surface of the screw shaft or the spiral raceway surface of the screw nut. DETAILED DESCRIPTION

[0105] The specific embodiments of the present invention will be described in detail below based on the accompanying drawings.

[0106] Figure 1 When the tapered roller screw pair has only one tapered roller circulating chain, the tapered roller screw pair comprises a screw shaft 1, a screw nut 2, a plurality of tapered rollers 3 and two tapered roller reversers 4, wherein the two tapered roller reversers 4 are respectively located at the two ends of the spiral teeth of the screw nut.

[0107] Figure 2 When the tapered roller screw pair bears axial load and operates normally, the tapered rollers in the tapered roller circulation chain perform circulating motion in the tapered roller circulation channel.

[0108] Figure 3 and Figure 4 The outer cylindrical surface of the screw shaft has a spiral tooth 11, and the two spiral raceway surfaces 11a and 11b of the spiral tooth 11 are both spiral raceway surfaces of the tapered roller 3. In order to prevent the tapered roller from sliding to the outside of the spiral raceway surface of the screw shaft under the action of the axial load, the outer edge of the spiral raceway surface 11a of the screw shaft has a rib 111; similarly, the outer edge of the spiral raceway surface 11b of the screw shaft also has a rib 112 structure. The material of the screw shaft can be metal and alloy such as GCr15, and the processing of the spiral tooth 11 can be achieved by turning or milling.

[0109] Figure 5The inner cylindrical surface of the lead screw nut has a helical tooth 21, and the two side surfaces 21a and 21b of the helical tooth are both raceway surfaces of the tapered roller. The lead screw nut can be made of metals and alloys such as GCr15, and the processing of the lead screw nut helical tooth 21 can be achieved by turning or milling.

[0110] Figure 6 The screw shaft helical teeth 11 and the screw nut helical teeth 21 have the same lead size, and the screw shaft helical teeth and the screw nut helical teeth 21 are arranged in a cross manner in the axial direction of the screw shaft.

[0111] Figure 7a , 7b, the large end face of the tapered roller is a convex spherical surface, and its radius is smaller than the curvature radius of the inner side faces 111a and 112a of the outer edge rib of the helical tooth of the screw shaft in any direction. The generatrix 3e of the outer conical surface of the tapered roller can be a straight line, or a circular arc or a conical arc convex outward. The material of the tapered roller can be metal and its alloy, or non-metal such as ceramics.

[0112] Figure 8 A plurality of tapered rollers 3 are arranged in the tapered roller channels CH1 and CH2 , and the helical surfaces 11a and 11b on both sides of the screw shaft helical tooth 11 and the helical surfaces 21a and 21b on both sides of the screw nut helical tooth 21 are both raceway surfaces of the tapered rollers 3 .

[0113] Fig. 9 In the tapered roller channels CH1 and CH2, the small ends of the tapered rollers are facing the inside of the screw shaft 1, and the large end faces of the tapered rollers are in contact with the inner side faces 111a and 112a of the outer edge ribs of the spiral teeth of the screw shaft to prevent the tapered rollers from sliding toward the outside of the spiral raceway surface of the screw shaft under the action of axial load.

[0114] Fig.10 and Fig.11 At both ends of the screw nut helical tooth 21, there are transition curved surfaces 21c and 21d, as well as wedge-shaped positioning surfaces 26, 27 and threaded holes 22, 23, 24, 25 for mounting the tapered roller deflector 4. The screw nut helical tooth can be machined by turning, and the wedge-shaped positioning surfaces 26, 27 can be machined by milling.

[0115] Fig.12 and Fig.13The concave curved surfaces 4a and 4d for guiding the concave roller to reverse are provided on the side of the concave roller deflector 4 facing the concave roller, wherein the concave curved surface 4a contacts the outer conical surface of the concave roller, and the curved surface 4d can contact the large end surface of the concave roller; the upper and lower end surfaces 4b and 4c of the concave roller deflector located in the spiral groove of the screw shaft are both spiral surfaces, and their lead is the same as the lead of the spiral teeth of the screw shaft 1. The roots of the two spiral end surfaces are provided with spiral grooves 43 and 44, and the lead of the two spiral grooves is also the same as the lead of the spiral teeth of the screw shaft 1. In addition, the concave roller deflector 4 is provided with a wedge-shaped positioning surface 4e and countersunk holes 41 and 42 for positioning and screw connection on the screw nut 2. The material of the concave roller deflector 4 can be metals and alloys such as CrWMn, or engineering plastics such as high-strength nylon, and its processing can be achieved by casting or powder metallurgy.

[0116] Fig.14 and Fig.15 , wherein two single-reverse-face tapered roller deflectors 4 are respectively fixed at the two ends of the extension of the helical teeth of the screw nut, and the tapered roller reverse action surfaces 4a of the two deflectors face one end surface 21c or 21d of the helical teeth of the screw nut. When the tapered roller deflector 4 is installed on the screw nut 2, it is first positioned by the wedge-shaped positioning surface 4e, and then fastened by screws.

[0117] Fig.16 and Fig.17 The two single-reverse tapered roller reversers 4 guide the tapered rollers to move in the opposite direction at the two ends of the helical teeth of the screw nut, so that the tapered rollers move from one side of the helical teeth of the screw nut to the other side of the helical teeth of the screw nut, thereby forming a complete tapered roller circulation chain.

[0118] Fig.18 The figure shows the movement posture of the tapered roller 3 of the tapered roller screw pair implemented in the present invention when entering or exiting the tapered roller reverse channel CH3 or CH4.

[0119] Fig.19 Because the tapered roller deflector 4 is fixed on the screw nut 2, and there is relative motion between the screw nut 2 and the screw shaft 1, there is also relative motion between the tapered roller deflector 4 and the screw shaft 1. In order to avoid geometric interference between the tapered roller deflector 4 and the screw shaft, there are gaps between the two spiral end faces 4b and 4c of the tapered roller deflector and the spiral teeth of the screw shaft, and there are also gaps between the two spiral grooves 43 and 44 of the tapered roller deflector and the spiral teeth of the screw shaft.

[0120] Fig. 20In the tapered roller channels CH1 and CH2, there is an axial gap Δ between the tapered roller and the spiral raceway surface of the screw shaft or the spiral raceway surface of the screw nut. The maximum value of the axial gap enables the tapered roller to move smoothly in the no-load return channel CH1 or CH2, thereby enabling the tapered roller to return to the starting end of its load travel channel.

[0121] Fig.21a , 21b, in the tapered roller channels CH1 and CH2, when the tapered roller transmits axial load, the contact lines 31 and 32 of the spiral raceway surfaces of the tapered roller, the screw shaft and the screw nut are both located in the normal plane N of the spiral motion trajectory S1 of the tapered roller, and the rotation axis 3c of the tapered roller and its extension line do not necessarily intersect with the center line 1c of the screw shaft. Only when the rotation axis of the tapered roller is perpendicular to the center line of the screw shaft, the extension line of the rotation axis of the tapered roller intersects with the center line of the screw shaft; in the tapered roller channels CH1 and CH2, the motion trajectory of any point on the rotation axis of the tapered roller and its extension line is a spiral line. Only when the tapered roller is perpendicular to the center line of the screw shaft, the extension line of the rotation axis of the tapered roller intersects with the center line of the screw shaft. When the extension line of the tapered roller's rotation axis intersects the center line of the screw shaft, the motion trajectory of the intersection is a straight line that coincides with the center line of the screw shaft; when the tapered roller transmits axial load, it intersects with the extension lines of the contact lines 31 and 32 of the screw shaft and the screw nut spiral raceway surface at a point J. The intersection J is located on the extension line of the tapered roller's rotation axis, but not necessarily on the center line of the screw shaft and its extension line. Only when the tapered roller's rotation axis is perpendicular to the center line of the screw shaft, and the distance between the intersection J and any point on the tapered roller's rotation axis is equal to the distance between the arbitrary point and the center line of the screw shaft, the intersection J is located on the center line of the screw shaft. According to the above geometric conditions, without considering the contact deformation between the tapered roller and the raceway surface, the motion of the tapered roller relative to the screw shaft and the spiral tooth surface of the screw nut can be pure rolling.

[0122] Fig. 22 The segmented structure of the screw nut helical teeth of the tapered roller screw pair implemented in the present invention when it has two tapered roller circulating chains is shown, the screw nut helical teeth 21 are divided into two sections in its spiral direction, and there is a window 212 for installing a double reverse surface tapered roller reverser 5 between the two sections of the screw nut helical teeth.

[0123] Fig.23 , Fig.24 and Fig.25The concave curved surfaces 5a and 5b on both sides of the double reverse surface tapered roller deflector are both the action surfaces that make the tapered roller do reverse motion, and the curved surfaces 5e and 5f are both the action surfaces that contact the large end surface of the tapered roller. Similar to the structure of the single reverse surface tapered roller deflector 4, the upper and lower end surfaces 5c and 5d of the double reverse surface tapered roller deflector 5 located in the spiral groove of the screw shaft are both spiral surfaces, and their leads are the same as the leads of the spiral teeth of the screw shaft, and there are spiral grooves 55 and 56 at the roots of these two spiral end surfaces, and their leads are also the same as the leads of the spiral teeth of the screw shaft. Because there is relative motion between the tapered roller deflector 5 and the spiral teeth of the screw shaft, there are geometric gaps between the two spiral end surfaces 5c and 5d of the tapered roller deflector 5 and the spiral teeth of the screw shaft, and there are also geometric gaps between the spiral grooves 55 and 56 and the outer edge ribs 111 and 112 of the spiral teeth of the screw shaft. In addition, the tapered roller deflector 5 is provided with positioning pin holes 51, 52 and countersunk holes 53, 54 for mounting the double reverse face tapered roller deflector 5 on the lead screw nut. The material of the double reverse face tapered roller deflector 5 can be metal and alloy such as CrWMn, or engineering plastics such as high-strength nylon, and its processing can be realized by casting or powder metallurgy.

[0124] Fig.26 Through the window 212 on the screw nut, the two reverse action surfaces 5a and 5b of the double reverse surface tapered roller reverser 5 are extended from the outside of the screw nut to the inside of the screw nut, and face the end faces of the helical teeth of the screw nuts on both sides respectively, thereby forming a tapered roller reverse channel CH5 and CH6 on both sides of the tapered roller reverser 5 respectively.

[0125] Fig. 27 and Fig.28 A complete tapered roller circulating chain is formed on both sides of the double reverse surface tapered roller reverser 5.

[0126] Fig.29 There are pin holes 28, 29 and threaded holes 210, 211 on the cylinder of the screw nut, wherein the pin holes 28, 29 are used to position the double reverse surface tapered roller reverser on the screw nut, and the threaded holes 210, 211 are used to fasten the double reverse surface tapered roller reverser.

[0127] Fig.30 , wherein the two contour lines 11a1 and 11b1 of the spiral raceway surface of the screw shaft are both circular arcs or conical arcs that curve inwardly toward the teeth, and the curvature radius of the circular arcs should be greater than the curvature radius of the generatrix 3e of the outer conical surface of the tapered roller.

[0128] Fig.31 , where the two contour lines 21a1 and 21b1 of the helical tooth surface of the screw nut are both arcs that curve inwardly of the teeth, and the curvature radius of the arcs should be greater than the curvature radius of the generatrix 3e of the outer conical surface of the tapered roller.

[0129] Fig.32 , and the present invention is attached Fig. 20 Similar to the fitting relationship in, in the unloaded return channel CH1 or CH2 of the tapered roller, the maximum axial clearance between the tapered roller and the helical tooth surface of the screw shaft or the helical tooth surface of the screw nut can allow the tapered roller to move smoothly.

[0130] Fig.33 , there is a separator 6 between any two adjacent tapered rollers 3. In a tapered roller circulating chain, the number of tapered rollers is determined according to the use requirements.

[0131] Fig.34a and Fig.34b The two side surfaces 6a and 6b of the tapered roller separator are both concave conical surfaces; the taper of these two conical side surfaces is the same as the taper of the tapered roller 3, and their small end radius and large end radius are respectively larger than the small end radius and large end radius of the tapered roller 3.

[0132] Fig.35 The figure shows the positional relationship between any two adjacent tapered rollers and their separators when the tapered roller screw pair implemented by the present invention has a separator in its tapered roller circulating chain.

[0133] Fig.36 The figure shows the assembly position relationship between a single tapered roller endless chain with a tapered roller separator and the helical teeth of a lead screw nut and two single-reverse-face tapered roller reversers implemented in the present invention.

[0134] Fig.37 The inner structure of the single reverse surface floating tapered roller deflector 7 implemented in the present invention is shown.

[0135] Fig.38 The inner structure of the single reverse surface floating tapered roller reverser according to the present invention is shown after the floating block 72 is removed.

[0136] Fig.39 The structure of the back plate 71 of the single-reverse floating tapered roller deflector implemented in the present invention is shown. The inner side of the back plate has a dovetail spiral guide groove 711. Because the guide surface of the guide groove 711 can withstand the overturning moment, the floating block 72 and the adjustment block 73 will not be separated from the guide groove when moving along the guide groove. The material of the back plate 71 can be engineering plastics, metals and alloys. During processing, the part blank can be first manufactured by casting or powder metallurgy, and then the guide groove 711 can be finely processed by forming milling or forming grinding.

[0137] Fig.40The structure of the floating block 72 of the single reverse surface floating tapered roller deflector implemented in the present invention is shown, and the outer side of the floating block has a dovetail guide surface for cooperating with the guide groove 711 on the inner side of the back plate 71, so that the floating block 72 can move along the guide groove of the back plate 71. The floating block 72 can be made of engineering plastics, metals and alloys. During processing, the part blank can be first manufactured by casting or powder metallurgy, and then the tapered roller reverse action surface 72e and the guide surfaces 72c and 72d can be finely processed by milling or grinding.

[0138] Fig.41a , Fig.41b and Fig.41c The structure of the adjustment block 73 of the single reverse floating tapered roller deflector of the present invention is shown, wherein the side close to the fixed block 74 has a wedge surface 73e for matching the wedge key 76, and the side close to the floating block 72 has a groove 731 for limiting the displacement of the fixed end of the leaf spring. The material of the adjustment block 73 can be engineering plastics, metals and alloys. During processing, the part blank can be first manufactured by casting or powder metallurgy, and then the guide surfaces 73c and 73d and the rectangular groove 731 can be finely processed by milling.

[0139] Fig.42 The structure of the leaf spring 75 of the single-reverse floating tapered roller deflector implemented in the present invention is shown, wherein the end 752 with the folded edge is the fixed end of the leaf spring, the other end is the free end, and the bent portion in the middle is the main elastic deformation portion of the leaf spring. The leaf spring can be made of high-strength spring steel.

[0140] Fig.43 The figure shows the assembly position relationship among the back plate, the wedge key and the adjustment block of the single reverse surface floating tapered roller reverser 7 implemented in the present invention.

[0141] Fig.44 The figure shows the assembly position relationship among the back plate, wedge key, adjustment block and fixed block of the single reverse surface floating tapered roller deflector 7 implemented in the present invention.

[0142] Fig.45 The figure shows the assembly position relationship among the back plate, the cover plate and the fixing block of the single reverse surface floating tapered roller deflector 7 implemented in the present invention.

[0143] Fig.46a and 46b The figure shows the external structure of the double reverse surface floating tapered roller reverser 8 implemented in the present invention.

[0144] Fig.47a, 47b shows the structure of the back plate 81 of the double reverse surface floating tapered roller reverser implemented in the present invention. The material of the part can be engineering plastics, metals and alloys. During processing, the blank of the part can be first manufactured by casting or powder metallurgy, and then the through hole 812 and other structures can be processed by milling, and finally the guide groove 811 can be finely processed by forming milling or forming grinding.

[0145] Fig.48a , 48b, Fig.49a , 49b shows the structure of the two floating blocks 82 and 83 of the double reverse surface floating tapered roller reverser implemented in the present invention. The materials of these two parts can be engineering plastics, metals and alloys, etc. During processing, the part blanks can be first manufactured by casting or powder metallurgy, and then the tapered roller reverse action surfaces 82e, 83e and floating guide surfaces 82c, 82d, 83c, 83d can be finely processed by milling or grinding.

[0146] Fig.50 The inner structure of the double reverse-surface floating tapered roller reverser of the present invention is shown after the two floating blocks 82 and 83 are removed, wherein the wedge-shaped portion of the wedge-shaped key 84 is located between the elastic action portions of the two leaf springs 85 and 86.

[0147] Fig.51 The structure of the leaf spring of the double reverse-surface floating tapered roller reverser implemented in the present invention is shown, wherein two through holes are provided at the fixed end 852 for fastening by screws.

[0148] Fig.52 The structure of the wedge key of the double reverse-face floating tapered roller reverser implemented in the present invention is shown, wherein the fixed end 842 has four countersunk holes for fastening by screws.

[0149] Fig.53 The figure shows the assembly position relationship between the back plate, leaf spring, wedge key, spring pressure plate and adjusting shim of the double reverse surface floating tapered roller reverser implemented by the present invention. By changing the thickness of the adjusting shim, the position of the wedge key relative to the leaf spring can be adjusted, thereby adjusting the distance between the two leaf springs and the compression deformation of the spring.

[0150] The center hole of the hollow screw shaft implemented by the present invention is not limited to Fig.54 The through hole structure shown in FIG. 55 also includes structures of other shaped center holes such as blind holes. Similarly, the center hole of the hollow tapered roller implemented in the present invention is not limited to the through hole structure shown in FIG. 55 , but also includes structures of other shaped center holes such as blind holes.

[0151] The tapered roller screw pair implemented by the present invention is not limited to a structure having only one or two tapered roller circulating chains, but also includes a structure having multiple tapered roller circulating chains. When the tapered roller screw pair has n (n>2) tapered roller circulating chains, the screw nut helical teeth 21 are divided into n discontinuous segments along the spiral direction, and there is a double reverse surface tapered roller deflector between the end faces of any two adjacent screw nut helical teeth, and there is a tapered roller deflector at the starting end of the first screw nut helical tooth and the terminal end of the last screw helical tooth, and the total number of tapered roller deflectors is n+1. In order to make the structure of the ball screw pair compact, the tapered roller deflectors can be evenly distributed in the circumferential direction of the screw nut 2. For example, when the tapered roller screw pair has two, three or four tapered roller circulating chains, the tapered roller deflectors are equally spaced at angles of 180°, 120° or 90° in the circumferential direction of the screw nut 2, respectively.

[0152] When the tapered roller screw pair implemented in the present invention is subjected to axial loads in opposite directions, axial movement will occur due to the existence of the internal axial clearance. For this purpose, the axial movement can be eliminated by using methods such as double nut adjustment pre-tightening.

[0153] A tapered roller screw pair mainly comprises a screw shaft 1, a screw nut 2, a tapered roller 3, and a tapered roller reverser 4. The screw shaft 1 has a helical tooth 11 on its outer cylindrical surface, and the screw nut 2 has a helical tooth 21 on its inner cylindrical surface. The helical teeth 11 of the screw shaft and the helical teeth 21 of the screw nut are arranged in a cross manner in the axial direction, that is, the helical teeth 11 of the screw shaft are located between the tooth grooves of the helical teeth 21 of the screw nut, and the helical teeth 21 of the screw nut are located between the tooth grooves of the helical teeth 11 of the screw shaft, so that a tapered roller is formed between one side surface 11a of the helical teeth of the screw shaft and the side surface 21a of the helical teeth of the screw nut adjacent thereto. A sub-channel, namely, a tapered roller channel CH1, is formed between another side surface 11b of the helical tooth of the screw shaft and the adjacent side surface 21b of the helical tooth of the screw nut, namely, a tapered roller channel CH2. A plurality of tapered rollers 3 are respectively arranged in the tapered roller channel CH1 and the tapered roller channel CH2. The two side surfaces 11a and 11b of the helical tooth 11 of the screw shaft and the two side surfaces 21a and 21b of the helical tooth 21 of the nut are both raceway surfaces of the tapered rollers 3. There is a tapered roller deflector 4 at both ends of the screw nut helical teeth 21, and the two tapered roller deflectors 4 form a tapered roller reverse channel at both ends of the screw nut helical teeth, namely, a tapered roller reverse channel CH3 and a tapered roller reverse channel CH4. The tapered roller deflector 4 can guide the tapered roller 3 from the tapered roller channel 1 CH1 to the tapered roller channel 2 CH2, or guide the tapered roller 3 from the tapered roller channel 2 CH2 to the tapered roller channel 1 CH1. The tapered roller reverse channel 3 CH3, the tapered roller reverse channel 4 CH4, the tapered roller channel 1 CH1 and the tapered roller channel 2 CH2 together form a complete tapered roller circulation channel. In one of the tapered roller circulation channels, multiple tapered rollers are arranged to form a complete tapered roller circulation chain.

[0154] In the tapered roller channel 1 CH1 and the tapered roller channel 2 CH2, the contact angles of the tapered rollers 3 when transmitting axial loads are in opposite directions, and thus can bear axial loads in opposite directions.

[0155] The tapered roller channel 1 CH1 and the tapered roller channel 2 CH2 are both the load travel channels and the no-load return channels of the tapered roller 3, that is, when the tapered roller screw pair is subjected to an axial load in any direction A or B, one of the tapered roller channel 1 CH1 and the tapered roller channel 2 CH2 that bears the axial load is the load travel channel of the tapered roller, and the other channel simultaneously serves as the no-load return channel of the tapered roller; when the axial load is reversed, the original tapered roller load travel channel becomes the tapered roller no-load return channel, and at the same time, the original tapered roller no-load return channel becomes the tapered roller load travel channel.

[0156] When the tapered roller screw pair is subjected to axial loads in opposite directions A and B, the maximum gap Δ between the tapered roller 3 and the spiral raceway surface of the screw shaft 1 or the spiral raceway surface of the screw nut 2 can allow the tapered roller 3 to move smoothly in its unloaded return channel, thereby enabling the tapered roller 3 to return to the starting end of its loaded travel channel.

[0157] The outer edge of the spiral raceway surface 11a of the screw shaft 1 has a rib 111, and the inner side surface 111a of the rib 111 contacts the large end surface 3b of the tapered roller 3; similarly, the outer edge of the spiral raceway surface 11b of the screw shaft 1 also has a rib 112, and the inner side surface 112a of the rib 112 contacts the large end surface 3b of the tapered roller 3.

[0158] The ratio of the length L of the tapered roller 3 to the large end diameter D is allowed to be greater than 1; the large end face 3b of the tapered roller 3 is a convex spherical surface, the radius of which is smaller than the radius of curvature of the inner side faces 111a and 112a of the outer edge rib of the screw shaft 1 in any direction; the generatrix 3e of the outer conical surface of the tapered roller 3 is a straight line or a circular arc or a conical arc convex outward.

[0159] In the tapered roller channel 1 CH1 and the tapered roller channel 2 CH2, when the tapered roller 3 is subjected to an axial load, without considering the contact deformation between the tapered roller and the raceway surface, the motion of the tapered roller relative to the screw shaft and the spiral raceway surface of the screw nut is pure rolling, and the contact lines 311 and 32 between the tapered roller and the two raceway surfaces are both located in the normal plane N of the tapered roller spiral motion trajectory S. In the tapered roller channel 1 CH1 and the tapered roller channel 2 CH2, the small end face 3a of the tapered roller 3 faces the inner side of the screw shaft 1, but the extension line of the rotation axis 3c of the tapered roller 3 does not necessarily intersect with the center line 1c of the screw shaft 1. Only when the rotation axis 3c of the tapered roller is perpendicular to the center line 1c of the screw shaft 1, the extension line of the rotation axis 3c of the tapered roller 3 intersects with the center line 1c of the screw shaft 1. In the tapered roller channel 1 CH1 and the tapered roller channel 2 CH2, when the tapered roller 3 transmits axial load, the motion trajectory of any point on the tapered roller rotation axis 3c and its extension line is a spiral line. Only when the extension line of the tapered roller rotation axis 3c intersects with the center line 1c of the screw shaft 1, the motion trajectory of the intersection is a straight line coinciding with the center line 1c of the screw shaft 1. In the tapered roller channel CH1 and the tapered roller channel CH2, when transmitting axial load, the tapered roller 3 intersects with the extension lines of the contact lines 31 and 32 of the screw shaft 1 and the screw nut 2 at a point J. The intersection J is located on the extension line of the rotation axis 3c of the tapered roller 3, but is not necessarily located on the center line 1c of the screw shaft 1 and its extension line. Only when the rotation axis 3c of the tapered roller 3 is perpendicular to the center line 1c of the screw shaft 1, and the distance between point J and any point on the tapered roller rotation axis 3c is equal to the distance between the arbitrary point and the center line 1c of the screw shaft, the intersection J is located on the center line 1c of the screw shaft 1. At this time, the motion trajectory of the intersection J is a straight line coinciding with the center line 1c of the screw shaft 1.

[0160] Both ends of the helical tooth 21 of the screw nut 2 have transition curved surfaces 21c and 21d.

[0161] The side surface 4a of the tapered roller reverser 4 that causes the tapered roller 3 to perform reverse motion is located between the tooth grooves of the helical teeth 11 of the screw shaft 1 and is located at the extension of the two ends of the helical teeth 21 of the screw nut. The side surface 4a on the tapered roller reverser 4 that reverses the tapered roller 3 and the side surface 4d that contacts the large end surface 3b of the tapered roller 3 are both concave curved surfaces. The shapes of the two concave curved surfaces can keep the movement posture of the tapered roller stable when entering and exiting the tapered roller reverse channel three CH3 and the tapered roller reverse channel four CH4, that is, the movement posture of the tapered roller in the tapered roller reverse channel three CH3 and the tapered roller reverse channel four CH4 near the port of the tapered roller channel one CH1 is close to its movement posture in the tapered roller channel one CH1, and the movement posture of the tapered roller in the tapered roller reverse channel three CH3 or the tapered roller reverse channel four CH4 near the port of the tapered roller channel two CH2 is close to its movement posture in the tapered roller channel two CH2.

[0162] The upper end face 4b and the lower end face 4c of the tapered roller deflector 4 located in the spiral tooth groove of the screw shaft are both spiral surfaces, and there are geometric gaps between the two spiral end faces and their adjacent spiral raceway surfaces of the screw shaft, and the roots of the two spiral end faces 4b and 4c of the tapered roller deflector 4 are both provided with grooves 43 and 44, and there are geometric gaps between the inner surfaces of the grooves 43 and 44 and the outer edge ribs 111 and 112 of the spiral teeth of the screw shaft 1.

[0163] The tapered roller screw pair may not only have one complete tapered roller circulating chain, but may also have two or more complete tapered roller circulating chains. When the tapered roller screw pair has two or more tapered roller circulating chains, the helical teeth 21 of the screw nut are divided into two or more discontinuous sections along the spiral direction, and both ends of each section of the screw nut helical teeth have transition surfaces, and there is a gap between any two adjacent sections of the screw nut helical teeth 21, and a double reverse surface tapered roller reverser 5 is arranged in the gap. Both sides of the double-reverse-face tapered roller reverser 5 are provided with action curved surfaces 5a and 5b for reversing the tapered roller 3. Meanwhile, the tapered roller channel 1 CH1 and the tapered roller channel 2 CH2 are divided into two or more sections by the double-reverse-face tapered roller reverser 5. Thus, each section of the spiral teeth 21 of the screw nut and the tapered roller reversers at both ends thereof form a complete tapered roller circulation channel. The multiple tapered rollers 3 form a tapered roller circulation chain in each tapered roller circulation channel, so that the tapered roller screw pair has two or more tapered roller circulation chains. The side surfaces 5a and 5b on both sides of the double-reverse-face tapered roller deflector 5 that are in contact with the outer tapered surface 3e of the tapered roller 3, and the surfaces 5e and 5f that are in contact with the large end surface of the tapered roller are all concave curved surfaces, and the upper 5c and lower end surfaces 5d of the double-reverse-face tapered roller deflector 5 located in the spiral tooth grooves of the screw shaft are both spiral surfaces, and there are geometric gaps between these two spiral end surfaces and the adjacent spiral raceway surfaces 11a or 11b of the screw shaft, and there are grooves 55 and 56 at the roots of these two spiral end surfaces, and there are geometric gaps between the inner surfaces of the grooves 55 and 56 and the outer edge ribs 111 and 112 of the spiral teeth of the screw shaft 1, thereby avoiding geometric interference between the double-reverse-face tapered roller deflector 5 and the spiral teeth 11 of the screw shaft 1.

[0164] When the generatrix 3e of the outer conical surface of the tapered roller 3 is an outwardly convex arc or conical arc, the contour lines 11a1 and 11b1 of the screw shaft spiral raceway surfaces 11a and 11b in the axial section containing the screw shaft center line 1c are straight lines, or arcs or conical arcs that bend inwardly into the teeth, and the contour lines 21a1 and 21b1 of the screw nut spiral raceway surfaces 21a and 21b in the axial section containing the screw nut center line 2c are also straight lines, or arcs or conical arcs that bend inwardly into the teeth. However, when the generatrix 3e of the outer conical surface of the tapered roller 3 is a straight line segment, in order to avoid geometric interference, the cross-sectional contour lines 11a1 and 11b1 of the screw shaft spiral raceway surface and the cross-sectional contour lines 21a1 and 21b1 of the screw nut spiral raceway surface cannot be arcs or conical arcs that bend inwardly into the teeth.

[0165] In the tapered roller circulation channel, any two adjacent tapered rollers 3 may be in direct contact, or a separator 6 may be provided between them. When a separator 6 is provided between two adjacent tapered rollers 3, the two tapered rollers 3 are respectively located on both sides of the separator 6, and transmit thrust or resistance by contacting the two side surfaces 6a and 6b of the separator; the two side surfaces 6a and 6b of the tapered roller separator are both concave conical surfaces, and the small end radius and the large end radius of the two conical side surfaces are respectively larger than the small end radius and the large end radius of the tapered roller 3.

[0166] The tapered roller reverser of the tapered roller screw pair can also adopt a floating structure, that is, under the contact load of the tapered roller 3, the reverse action surface of the tapered roller reverser can float along the spiral groove of the screw shaft, and has stiffness and damping that meet the use requirements in the floating direction. Because the single reverse surface tapered roller reverser 4 and the double reverse surface tapered roller reverser 5 do not have the floating function, when the tapered roller reverser of the tapered roller screw pair is required to float relative to the tapered roller in contact with it, it is replaced by a single reverse surface floating tapered roller reverser 7 and a double reverse surface floating tapered roller reverser 8 respectively.

[0167] The single-reverse floating tapered roller reverser is mainly composed of a back plate 71, a floating block 72, an adjustment block 73, a fixed block 74, a plate spring 75, a wedge key 76 and a cover plate 77; the inner side of the back plate 71 is provided with a guide groove 711, the guide track of the guide groove is a spiral line, and its lead is the same as the lead of the spiral groove of the screw shaft 1, the floating block 72 can move along the guide groove 711, and the adjustment block 73 can also move along the guide groove 711 of the back plate; the fixed block 74 is fixed to the screw nut of the tapered roller screw pair by screws, and a wedge key 76 is provided between the fixed plate 74 and the adjustment block 73, and a plate spring 74 is provided between the adjustment block 73 and the floating block 72, and the adjustment block 73 can be displaced along the guide groove 711 by adjusting the position of the wedge key 76, so that the distance between the adjustment block 73 and the floating block 72 and the plate spring 74 can be changed. The plate spring 74 can apply a preload to the floating block 72 after being deformed by pressure, and the floating block 72 can float along the guide groove 711 of the back plate when impacted by the tapered roller; the upper end face 72a and lower end face 72b of the floating block and the upper end face 73a and lower end face 73b of the adjusting block 73 are all helical surfaces, and their leads are the same as the leads of the helical grooves of the screw shaft 1; the plate spring 75 is located between the floating block 72 and the adjusting block 73, and its fixed end 752 is placed in the rectangular groove 731 of the adjusting block 73; the cover plate 77 is located on the outside of the large end of the wedge key 76, and is fixedly connected with the wedge key 76, the back plate 71 and the fixing block 74 by screws, and an adjusting gasket is provided between the cover plate 77, the back plate 71 and the fixing block 74, and the position of the wedge key 76 is adjusted by changing the thickness of the adjusting gasket, so that the position of the adjusting block 73 in the guide groove 711 can be changed.

[0168] The double reverse surface floating tapered roller deflector is mainly composed of a back plate 81, floating blocks 82 and 83, a wedge key 84, leaf springs 85 and 86, a pressure plate 87 and a gasket 88; the inner side of the back plate 81 is provided with a guide groove 811, the guide track of the guide groove is a spiral line, and its lead is the same as the lead of the spiral groove of the screw shaft 1; the floating block 82 can float along the back plate guide groove 811 when impacted by the tapered roller, and similarly, the floating block 83 can also float along the back plate guide groove 811 when impacted by the tapered roller; the tapered roller reverse action surfaces 82e and 83e of the two floating blocks 82 and 83 are respectively facing the tapered rollers on both sides of the double reverse surface floating tapered roller deflector; the two leaf springs 85 and 86 are placed between the two floating blocks 82 and 83 in a back-to-back or face-to-face manner, and between the two leaf springs There is a wedge key 84 between the two leaf springs, and the distance between the two leaf springs and the deformation of the leaf springs can be changed by adjusting the position of the wedge key; the leaf springs 85 and 86 can apply a preload to the floating blocks 82 and 83 after being deformed by pressure; the middle part of the back plate 81 has a through hole 812, and the wedge-shaped part of the wedge key 84 and the elastic action parts of the leaf springs 85 and 86 are all inserted into the inner side of the back plate from the back plate through hole 812; in the position adjustment direction along the wedge key 84, there is an adjustment gasket 88 between the leaf springs 85 and 86 and the wedge key 84, and the position of the wedge key 84 relative to the leaf springs 85 and 86 can be adjusted by changing the thickness of the adjustment gasket, thereby changing the distance between the two leaf springs; the wedge key 84, the two leaf springs 85 and 86 and the adjustment gasket 88 are all fixed to the back plate 81 by fastening screws.

[0169] The screw shaft 1 and the tapered roller 3 can be not only solid structures but also hollow structures. When the tapered roller screw pair eliminates the internal axial clearance and play by adjusting and pre-tightening the double screw nuts, the methods that can be used include the double nut tooth difference adjustment and pre-tightening method, the double nut thread adjustment and pre-tightening method, the double nut gasket adjustment and pre-tightening method, etc.

[0170] The tapered roller screw pair provided by the present invention is not limited to the above-mentioned embodiments, and also includes other embodiments that can realize its structure and function. In addition, a damping element can be arranged between the two floating blocks of the double reverse surface floating tapered roller reverser, so that the vibration generated by the impact of the tapered roller can be further reduced.

[0171] The embodiments described above are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements of the present invention by relevant technical personnel in the field should be extended within the scope of protection determined by the claims of the present invention.

Claims

1. A tapered roller screw pair, comprising a screw shaft, a screw nut, a tapered roller, and a tapered roller reverser, characterized in that: The screw shaft is provided with helical teeth on its outer cylindrical surface, and the screw nut is provided with helical teeth on its inner cylindrical surface. The helical teeth of the screw shaft and the helical teeth of the screw nut are arranged in a cross manner in the axial direction, that is, the helical teeth of the screw shaft are located between the tooth grooves of the helical teeth of the screw nut, and the helical teeth of the screw nut are located between the tooth grooves of the helical teeth of the screw shaft; a tapered roller channel 1 is formed between one side surface of the helical teeth of the screw shaft and the side surface of the adjacent helical teeth of the screw nut, and a tapered roller channel 2 is formed between the other side surface of the helical teeth of the screw shaft and the side surface of the adjacent helical teeth of the screw nut; a plurality of tapered rollers are located in the channel between the helical teeth of the screw shaft and the helical teeth of the screw nut, and both side surfaces of the helical teeth of the screw shaft and the screw nut are both raceway surfaces of the tapered rollers, and the contact between the tapered rollers and the raceway surfaces is Line contact; the two ends of the screw nut helical teeth are respectively provided with a tapered roller deflector, and the tapered roller deflector forms a tapered roller reverse channel at the two ends of the screw nut helical teeth, respectively, which are recorded as tapered roller reverse channel three and tapered roller reverse channel four. The tapered roller is guided from any side channel of the screw nut helical teeth to the other side channel through the tapered roller deflector, that is, from the tapered roller channel one to the tapered roller channel two, or from the tapered roller channel two to the tapered roller channel one; the tapered roller reverse channel three, the tapered roller reverse channel four, the tapered roller channel one and the tapered roller channel two together form a complete tapered roller circulation channel, in one of the tapered roller circulation channels, a plurality of tapered rollers are arranged to form a complete tapered roller circulation chain; The outer edges of the spiral raceway surfaces of the tapered rollers on both sides of the spiral teeth of the screw shaft are provided with protruding rib structures, and the inner side surfaces of the ribs are in contact with the large end surfaces of the tapered rollers; The ratio of the length L of the tapered roller to the large end diameter D is allowed to be greater than 1; The large end surface of the tapered roller is a convex spherical surface, the radius of which is smaller than the radius of curvature of the inner side surface of the outer edge rib of the screw shaft in any direction; the generatrix of the outer conical surface of the tapered roller is a straight line or an outwardly convex circular arc or conical arc; In the tapered roller channel one and the tapered roller channel two, the contact lines between the tapered roller and the spiral raceway surface of the screw shaft and the spiral raceway surface of the screw nut are all located in the normal plane N of the spiral motion trajectory S of the tapered roller; in the tapered roller channel one and the tapered roller channel two, the small end face of the tapered roller faces the inner side of the screw shaft; in the tapered roller channel one and the tapered roller channel two, when the tapered roller transmits an axial load, the extension line of the tapered roller's rotation axis does not necessarily intersect with the center line of the screw shaft. Only when the tapered roller's rotation axis is perpendicular to the center line of the screw shaft, the extension line of the tapered roller's rotation axis intersects with the center line of the screw shaft; in the tapered roller channel one and the tapered roller channel two, when the tapered roller transmits an axial load, the tapered roller The motion trajectory of any point on the tapered roller's rotation axis and its extension line is a spiral line. Only when the extension line of the tapered roller's rotation axis intersects with the center line of the screw shaft, the motion trajectory of the intersection on the extension line of the tapered roller's rotation axis is a straight line that coincides with the center line of the screw shaft. When transmitting axial load, the tapered roller intersects with the extension line of the contact line of the screw shaft and the screw nut at a point, recorded as point J. The intersection is located on the extension line of the tapered roller's rotation axis. When the tapered roller's rotation axis is perpendicular to the center line of the screw shaft, and the distance between the intersection J and any point on the tapered roller's rotation axis is equal to the distance between the arbitrary point and the center line of the screw shaft, the intersection J is located on the center line of the screw shaft, and the motion trajectory of the intersection is a straight line that coincides with the center line of the screw shaft.

2. The tapered roller screw pair according to claim 1, characterized in that: Both ends of the helical teeth of the lead screw nut are provided with transition curved surfaces.

3. The tapered roller screw pair according to claim 2, characterized in that: The action surface on the tapered roller reverser that causes the tapered roller to reverse is located between the tooth grooves of the helical teeth of the screw shaft, and is located at the extensions of the two ends of the helical teeth of the screw nut; the action surface on the tapered roller reverser that causes the tapered roller to reverse and the action surface on the tapered roller reverser that contacts the large end surface of the tapered roller are both concave surfaces, and the shape of the concave surface can keep the movement posture of the tapered roller stable when entering and exiting the tapered roller reverse channel three and the tapered roller reverse channel four.

4. The tapered roller screw pair according to claim 3, characterized in that: The upper end face and the lower end face of the tapered roller deflector located in the spiral tooth groove of the screw shaft are both spiral surfaces, and there are geometric gaps between the two spiral end faces and their adjacent spiral raceway surfaces of the screw shaft, and the roots of the two spiral end faces of the tapered roller deflector are both provided with grooves, and there is also a geometric gap between the inner surface of the groove and the outer edge rib of the spiral tooth of the screw shaft.

5. The tapered roller screw pair according to claim 4, characterized in that: The tapered roller screw pair has one complete tapered roller circulating chain, and may also have two or more complete tapered roller circulating chains; when the tapered roller screw pair has two or more complete tapered roller circulating chains, the helical teeth of the screw nut are divided into two or more discontinuous sections along the spiral direction, both ends of the helical teeth of each section of the screw nut have transition surfaces, and there is a gap between any two adjacent end faces of the helical teeth, and a double-reverse-face tapered roller deflector is arranged in the gap; both sides of the double-reverse-face tapered roller deflector have action surfaces that reverse the tapered rollers, and the tapered roller channel 1 and the tapered roller channel 2 are divided into two or more sections by the double-reverse-face tapered roller deflector, Each section of the spiral tooth of the screw nut and the tapered roller deflectors at both ends thereof form a complete tapered roller circulation channel, and a plurality of the tapered rollers can form a tapered roller circulation chain in each tapered roller circulation channel; the working surfaces on both sides of the double-reverse-face tapered roller deflector that contact the outer conical surface of the tapered roller and the working surfaces that contact the large end surface of the tapered roller are both concave surfaces; the upper end surface and the lower end surface of the double-reverse-face tapered roller deflector located in the spiral tooth groove of the screw shaft are both spiral surfaces, and there are geometric gaps between these two spiral end surfaces and the adjacent spiral raceway surfaces of the screw shaft, and there are grooves at the roots of these two spiral end surfaces, and there are also geometric gaps between the inner surfaces of the grooves and the outer edge ribs of the spiral teeth of the screw shaft.

6. The tapered roller screw pair according to claim 5, characterized in that: When the generatrix of the outer conical surface of the tapered roller is an outwardly convex arc or conical arc, the tooth surface contour line of the spiral raceway surface on the screw shaft in the normal section of the spiral teeth of the screw shaft is a straight line, or a circular arc or conical arc bent inwardly toward the teeth; the contour line of the spiral raceway surface on the screw nut in the normal section of the spiral teeth of the screw nut is a straight line, or a circular arc or conical arc bent inwardly toward the teeth.

7. The tapered roller screw pair according to claim 6, characterized in that In the tapered roller circulation channel, any two adjacent tapered rollers are in direct contact, or a separator is arranged between them; when a separator is arranged between two adjacent tapered rollers, the two tapered rollers are respectively located on both sides of the separator, and transmit thrust or resistance by contacting the two side surfaces of the separator; the two side surfaces of the tapered roller separator are both concave conical surfaces, and the small end radius and large end radius of the two conical side surfaces are respectively larger than the small end radius and large end radius of the tapered roller.

8. The tapered roller screw pair according to claim 7, characterized in that: The tapered roller reverse action surface of the tapered roller reverser of the tapered roller screw pair is a fixed or floating structure relative to the tapered roller in contact with it; when the tapered roller reverse action surface of the tapered roller reverser is floating relative to the tapered roller in contact with it, the tapered roller reverse action surface of the tapered roller reverser can float along the spiral groove of the screw shaft under the contact load of the tapered roller, and has stiffness and damping that meet the use requirements in the floating direction; when the tapered roller screw pair adopts a floating tapered roller reverser, the single reverse face tapered roller reverser and the double reverse face tapered roller reverser are replaced by a single reverse face floating tapered roller reverser and a double reverse face floating tapered roller reverser respectively.

9. The tapered roller screw pair according to claim 8, characterized in that: The single reverse surface floating tapered roller deflector comprises a back plate, a floating block, an adjusting block, a fixed block, a plate spring and a wedge key; the inner side of the back plate is provided with a guide groove, the guide track of the guide groove is a spiral line, and its lead is the same as the lead of the spiral groove of the screw shaft, the floating block can move along the back plate guide groove, and the adjusting block can also move along the back plate guide groove; the fixed block is fixed on the screw nut, the wedge key is located between the fixed block and the adjusting block, and the plate spring is located between the adjusting block and the floating block. By adjusting the position of the wedge key, the position of the adjusting block in the back plate guide groove can be changed, thereby changing the distance between the adjusting block and the floating block and the deformation of the plate spring; the plate spring applies a preload to the floating block after being deformed by compression, so that the floating block can float along the guide groove of the back plate when impacted by the tapered roller; the upper end face and lower end face of the floating block and the upper end face and lower end face of the adjusting block are all spiral surfaces, and their leads are the same as the lead of the spiral groove of the screw shaft.

10. The tapered roller screw pair according to claim 8, characterized in that: The double reverse surface floating tapered roller reverser comprises a back plate, a floating block 1, a floating block 2, a wedge key and a plate spring; the inner side of the back plate is provided with a guide groove, the guide track of the guide groove is a spiral line, and its lead is the same as the lead of the spiral groove of the screw shaft; the floating block 1 and the floating block 2 can float along the back plate guide groove when impacted by the tapered roller; the tapered roller reverse action surfaces on the floating block 1 and the floating block 2 are respectively located on both sides of the double reverse surface floating tapered roller reverser, and respectively face the tapered roller channels on both sides of the double reverse surface floating tapered roller reverser; the plate spring and the wedge key are both placed between the floating block 1 and the floating block 2, and the plate spring applies a preload to the floating block 1 and the floating block 2 after being deformed by compression, and the deformation amount of the plate spring and the size of the preload are changed by adjusting the wedge key.

11. The tapered roller screw pair according to claim 1, characterized in that: The screw shaft and the tapered roller are solid structures or hollow structures.

12. The tapered roller screw pair according to claim 8, characterized in that: The tapered roller screw pair eliminates the axial clearance by adjusting the pre-tightening mode of the double screw nuts.

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