CN-224214649-U - Roller screw bidirectional staggered pre-pressing structure with built-in spring plate

CN224214649UCN 224214649 UCN224214649 UCN 224214649UCN-224214649-U

Abstract

The utility model provides a roller screw bi-directional staggered pre-pressing structure with built-in spring plates, wherein the outer circumferential surface of the screw is provided with a threaded structure, a nut is sleeved on the screw, and the inner circumferential surface of the nut is provided with a ring-shaped groove section and two limiting grooves. The roller set is arranged between the screw and the nut and comprises a first roller and a second roller which are staggered, and the periphery of each roller is provided with annular teeth which are respectively meshed with the thread structure and the annular groove section. The two retaining and prepressing units are respectively arranged at two opposite ends of the roller group, each retaining and prepressing unit comprises a retainer and a spring plate, the two retainers are respectively provided with a plurality of retaining holes for respectively accommodating the positioning ends of the rollers, and the spring plate is provided with elastic tilting feet which are arranged in a radial dislocation way relative to the retaining holes and are respectively propped against the tips of the rollers. The axial precompression with opposite directions is applied to the first roller and the second roller respectively to form a precompression effect of bidirectional interlacing, thereby compensating the clearance, and improving the transmission precision and the motion stability.

Inventors

LIN JUNHAN
ZENG YONGZHI
HUANG SHUNYONG
CHEN BAIYUN

Assignees

富世达股份有限公司

Dates

Publication Date: 20260508
Application Date: 20250604

Claims (11)

1. The utility model provides a built-in shell fragment's two-way staggered pre-compaction structure of roller screw rod which characterized in that includes: a screw with a thread structure on its outer circumference; The nut is sleeved on the screw rod, and the inner peripheral surface of the nut is provided with at least one annular groove section and two limit grooves; The roller group is arranged between the screw and the nut and is provided with a plurality of first rollers and a plurality of second rollers which are arranged in a staggered way, a first positioning end and a first tip are respectively formed at two ends of each first roller, a second positioning end and a second tip which are opposite to the two ends of each first roller are respectively formed at two ends of each second roller, annular teeth are arranged on the periphery of each roller, and the annular teeth are respectively meshed with the thread structure and the annular groove section; The two retaining and pre-pressing units are arranged in the nut and are respectively positioned at two ends of the roller group, each retaining and pre-pressing unit comprises a retainer and a spring plate, the retainer is provided with a plurality of retaining holes, the retaining holes of the two retainers respectively accommodate the first positioning end and the second positioning end, the spring plates are arranged between the inner side of the retainer and the roller group, a plurality of elastic raising feet which tilt and raise towards the roller group are formed along the circumferential direction, the elastic raising feet are arranged in a radial dislocation mode relative to the retaining holes, and the elastic raising feet of the two spring plates respectively elastically prop against the first tip and the second tip; The fastener group is provided with two fasteners which are respectively arranged at the outer sides of the two holding pre-pressing units and are embedded in the limiting groove so as to axially limit the two holding pre-pressing units in the nut; The elastic tilting pins and the holding holes are arranged in a radial dislocation way, so that the first tip and the second tip respectively prop against the elastic tilting pins of the two elastic sheets, the elastic tilting pins are elastically deformed, a first gap and a second gap are formed between the first positioning end and the second positioning end and the bottoms of the corresponding holding holes respectively, the first tip and the second tip respectively transmit precompression in opposite directions, and axial precompression in opposite directions is applied to the first roller and the second roller, so that bidirectional staggered precompression is formed at two ends of the roller group, back clearance between the screw and the nut is reduced, and pure rolling contact of the rollers is maintained.
2. The structure of claim 1, wherein the retainer has a plurality of engaging grooves, the spring is a ring spring, and a plurality of engaging pins are provided on the outer edge of the spring, and the plurality of engaging pins are correspondingly engaged into the plurality of engaging grooves to be detachably positioned.
3. The structure of claim 1, wherein the elastic pins of the spring plate have a groove, and the first and second tips correspond to the groove, respectively.
4. The structure of claim 3, wherein the recess is a circular arc recess or a conical recess, and the first tip and the second tip are conical and form a point contact with the recess.
5. The structure of claim 1, wherein the plurality of elastic pins are arranged at radial intervals and are tilted when not being stressed.
6. The structure of claim 1, wherein a bearing is disposed between the retaining and pre-pressing unit and the fastener.
7. The structure of claim 1, wherein the retainer and the spring are integrally formed.
8. The utility model provides a built-in shell fragment's two-way staggered pre-compaction structure of roller screw rod which characterized in that includes: The outer peripheral surface of the screw rod is provided with a thread structure; The nut is sleeved outside the screw rod, and the inner peripheral surface of the nut is provided with at least one annular groove section and two limit grooves; The roller group is arranged between the screw and the nut and is provided with a plurality of first rollers and a plurality of second rollers which are arranged in a staggered way, a first positioning end and a first tip are formed at the opposite ends of each first roller, a second positioning end and a second tip which are opposite to the opposite ends of each first roller are formed at the opposite ends of each second roller, annular teeth are arranged on the periphery of each roller, and the annular teeth are respectively meshed with the thread structure and the annular groove section; The two retaining and prepressing units are respectively arranged at the two opposite ends of the roller group, each retaining and prepressing unit comprises an elastic sheet, the elastic sheet is provided with a plurality of positioning holes and a plurality of elastic tilting feet which tilt towards the roller group, the positioning holes of the two elastic sheets are respectively provided with the first positioning end and the second positioning end, the elastic tilting feet of the two elastic sheets are arranged in a radial dislocation way relative to the positioning holes and respectively elastically support against the corresponding first pointed end and second pointed end; The fastener group is provided with two fasteners which are respectively arranged at the outer sides of the two holding pre-pressing units and embedded in the limiting groove, and is used for fixing the two holding pre-pressing units and axially limiting the two holding pre-pressing units in the nut; The first tip and the second tip are respectively propped against the elastic tilting feet of the two elastic sheets by virtue of radial dislocation configuration of the elastic tilting feet and the positioning holes, and the elastic tilting feet are elastically deformed, so that a first gap and a second gap are formed between the first positioning end and the second positioning end and the corresponding positioning holes respectively, the first tip and the second tip respectively transmit precompression in opposite directions, and axial precompression in opposite directions is applied to the first roller and the second roller, so that bidirectional staggered precompression is formed at two ends of the roller group, back clearance between the screw rod and the nut is reduced, and pure rolling contact of the rollers is maintained.
9. The roller screw bi-directional staggered pre-pressing structure of the built-in spring plate as claimed in claim 8, wherein: the elastic seesaw foot is provided with a free end, the free end is provided with a groove, and the groove is in point contact with the corresponding first tip or second tip.
10. The structure of claim 9, wherein the groove is a circular arc groove or a conical groove, and the first tip and the second tip are conical and form point contact with the groove.
11. The structure of claim 8, wherein a bearing or a spacer is disposed between each spring and the fastener.

Description

Roller screw bidirectional staggered pre-pressing structure with built-in spring plate Technical Field The utility model relates to a transmission assembly, in particular to a roller screw bidirectional staggered pre-pressing structure of a built-in spring plate, which can axially pre-press rollers to improve rolling stability. Background The planetary roller screw transmission assembly (also called planetary roller screw) has high load bearing capacity, high rigidity, excellent transmission efficiency and positioning accuracy, and is widely applied to occasions requiring quick response and high dynamic performance, such as precision machine tools, servo driving systems, aerospace control devices, high-performance robots and the like. The basic structure is that a plurality of rollers are arranged between a screw and a nut and wound around the periphery of the screw, and the rollers are engaged with the screw and the nut in a rolling way so as to convert rotary motion into linear motion and further drive an external load. As shown in FIG. 1A, a typical planetary roller screw drive includes a screw 11, a nut 12, a plurality of rollers 13, and a set of holders 14. The screw 11 has an external thread structure, the nut 12 is provided with an inner hole 120 for accommodating the plurality of rollers 13, and an annular tooth structure 12t is provided on the inner periphery of the nut 12 for engaging with the outer annular teeth of the rollers 13 to form rolling contact. The retainer sets 14 are disposed at axial ends of the rollers 13, and are used for positioning the rollers 13 between the screw 11 and the nut 12 and maintaining the circumferential spacing therebetween. However, in practical operation, the conventional device still has a plurality of problems. As shown in fig. 1B and 1C, the geometric fit among the roller 13, the screw 11 and the nut 12 is very precise, however, a small gap G is generated between the roller 13 and the screw 11/nut 12 due to manufacturing tolerance and assembly error, so that the actual contact position of the roller 13 deviates from the designed pitch radius. If the complex fit gap G is not compensated effectively, the lack of sufficient friction between the roller 13 and the nut 12 will cause sliding or lost motion, making it difficult to maintain pure rolling contact with sliding friction. Thus causing the rollers 13 to experience greater wear and reducing overall structural life. Similarly, the roller 13 and the screw 11 may slide due to insufficient contact, so as to destroy the speed reduction and propulsion effects of the planetary motion, and reduce the linear propulsion efficiency and positioning accuracy. In addition, although the conventional retainer set 14 can perform end restriction and angular distribution control on the roller 13, the component only has a mechanical positioning function, and cannot provide preload compensation or the capability of guiding the movement direction of the roller, and cannot effectively solve the problem of sliding offset of the roller 13 due to the gap G. Therefore, how to effectively improve the contact stability between the roller 13 and the nut 12 and strengthen the rolling engagement between the roller 13 and the screw 11 without increasing the structural complexity and the manufacturing cost, so as to ensure that the screw 11, the roller 13 and the nut 12 maintain stable rolling motion is an important subject to be overcome in the field. Disclosure of utility model The utility model aims to provide a roller screw bidirectional staggered pre-pressing structure of a built-in spring plate, which can solve the technical problems, can effectively compensate a fit clearance caused by machining errors, and respectively apply axial pre-pressing force in opposite directions to two rollers which are staggered so as to realize a stable bidirectional rolling contact effect, further improve the overall transmission efficiency, reduce abrasion and prolong the service life. In order to achieve the above purpose, the present utility model provides a roller screw bi-directional staggered pre-pressing structure with built-in spring plates, which is characterized by comprising: a screw with a thread structure on its outer circumference; The nut is sleeved on the screw rod, and the inner peripheral surface of the nut is provided with at least one annular groove section and two limit grooves; The roller group is arranged between the screw and the nut and is provided with a plurality of first rollers and a plurality of second rollers which are arranged in a staggered way, a first positioning end and a first tip are respectively formed at two ends of each first roller, a second positioning end and a second tip which are opposite to the two ends of each first roller are respectively formed at two ends of each second roller, annular teeth are arranged on the periphery of each roller, and the annular teeth are respectively meshed with the thread structur