阅读说明：本技术 一种差动式行星滚柱丝杠副 (Differential planetary roller screw pair ) 是由 杜伟 王云菊 李保民 于 2020-11-25 设计创作，主要内容包括：本发明涉及一种差动式行星滚柱丝杠副,属于传动装置技术领域,包括丝杠、螺母以及安装在丝杠与螺母之间若干个滚柱,螺母分为三段,滚柱也分为三段,滚柱的中间段的螺纹与丝杠的螺纹相互啮合,滚柱中间段两端的部分的螺纹与螺母的内螺纹相互啮合,滚柱的数量为偶数,每种滚柱的数量为两个,偶数个滚柱在丝杠与螺母之间是间隔安装的,即相邻的两个滚柱之间都是不同的,滚柱的两端由保持架固定,保持架的外侧还安装有挡圈。本发明支撑稳定,可防止倾斜,简化了传统结构,具有更大的传动比,继承了行星滚柱丝杠副的传统优势,因结构更简单,在相同体积和重量下可以承受更高的载荷,并且具有更高的输入转速、更小的导程和更大的减速比等优点。(The invention relates to a differential planetary roller screw pair, which belongs to the technical field of transmission devices and comprises a screw, a nut and a plurality of rollers arranged between the screw and the nut, wherein the nut is divided into three sections, the rollers are also divided into three sections, threads at the middle sections of the rollers are meshed with threads of the screw, threads at the two ends of the middle sections of the rollers are meshed with internal threads of the nut, the number of the rollers is even, the number of each roller is two, the rollers with even number are arranged between the screw and the nut at intervals, namely the two adjacent rollers are different, the two ends of each roller are fixed by a retainer, and a retainer ring is arranged on the outer side of the retainer. The planetary roller screw pair has the advantages of stable support, inclination prevention, simplification of the traditional structure, higher transmission ratio, higher load bearing capacity under the same volume and weight, higher input rotating speed, smaller lead, higher reduction ratio and the like, inherits the traditional advantages of the planetary roller screw pair, and is simpler in structure.)

1. The utility model provides a differential type planet roller screw is vice, includes lead screw (1), nut (2) and installs a plurality of roller (3) between lead screw (1) and nut (2), its characterized in that: the nut (2) is divided into three sections, the inner diameter of the part of the middle section in the nut (2) is larger, no internal thread is arranged, and the inner diameters of the parts at two ends of the middle section in the nut (2) are smaller than that of the middle section and are provided with internal threads;

each roller (3) is divided into three sections, the thread parameters of the roller (3) in the middle section are different from those of the parts at the two ends of the middle section of the roller (3), but the thread lead angles of the three sections of threads of the stud (3) are all zero, the diameter of the middle section of the roller (3) is larger, the diameters of the parts at the two ends of the middle section of the roller (3) are smaller than that of the middle section, the threads of the middle section of the roller (3) are meshed with the threads of the screw rod (1), the threads of the parts at the two ends of the middle section of the roller (3) are meshed with the internal threads of the nut (2), a gap is formed between the threads of the parts at the two ends of the middle section of the roller (3) and the threads of the screw rod (1), in addition, the two ends of the roller (3) are respectively provided with an;

the number of the rollers (3) is even, the number of each roller (3) is two, the rollers (3) with the even number are installed between the screw rod (1) and the nut (2) at intervals, namely the two adjacent rollers (3) are different, two ends of each roller (3) are fixed by the retainer (4), and the outer side of each retainer (4) is further provided with the retainer ring (5).

2. The differential planetary roller screw set of claim 1, wherein: the difference between the rollers (3) is that the axial dimension between the thread bottom at the extreme end of the middle section of the roller (3) and the end surface of the roller (3) is different, namely the value of X is different.

3. A differential planetary roller screw set according to claim 1 or 2, characterized in that: the thread on the lead screw (1) is a single-head external thread with a helix angle.

Technical Field

The invention relates to a differential planetary roller screw pair, belonging to the technical field of transmission devices.

Background

The planetary roller screw pair is a mechanical transmission device capable of mutually converting rotary motion and linear motion, has the comprehensive characteristics of screw transmission and rolling screw transmission, and has the characteristics of high bearing capacity and impact resistance compared with a common transmission part, namely a ball screw pair. The existing planetary roller screw transmission mechanism mainly comprises the following components according to the difference of the structure composition and the relative motion relationship of parts: standard planetary roller screw transmission; reverse planetary roller screw transmission; circulating planetary roller screw transmission; bearing type planetary lead screw transmission and the like. The common characteristics of the planetary roller screw pair of the types include main parts such as a screw, a nut, a roller, an inner gear ring, a retainer ring and the like, wherein the screw and the nut are multi-thread threads with a helix angle; the roller is a single-head thread with a helix angle, and two ends of the roller are provided with gears meshed with the inner gear ring. The structure is complicated, the processing and the assembly are more complicated, the bearable load is smaller, and the input rotating speed is lower.

Disclosure of Invention

The invention aims to solve the defects in the prior art and provide a differential planetary roller screw pair which can bear larger load and has higher input rotating speed.

The invention is realized by the following technical scheme:

the differential planetary roller screw pair comprises a screw rod, a nut and a plurality of rollers arranged between the screw rod and the nut, wherein the nut is divided into three sections, the inner diameter of the middle section in the nut is larger, no internal thread is arranged, and the inner diameters of the two ends of the middle section in the nut are smaller than that of the middle section and are provided with internal threads;

each roller is divided into three sections, the thread parameters of the roller at the middle section are different from the thread parameters of the parts at the two ends of the middle section of the roller, but the thread lead angles of the three threads at the three sections of the stud are zero, the diameter of the middle section of the roller is larger, the diameters of the parts at the two ends of the middle section of the roller are smaller than the diameter of the middle section of the roller, the threads of the middle section of the roller are meshed with the threads of the screw rod, the threads of the parts at the two ends of the middle section of the roller are meshed with the internal threads of the nut, meanwhile, a gap exists between the threads of the parts at the two ends of the middle section of the roller and the threads of the;

the number of the rollers is even, the number of each roller is two, the even rollers are arranged between the screw rod and the nut at intervals, namely the two adjacent rollers are different, two ends of each roller are fixed by the retainer, and the retainer ring is arranged on the outer side of the retainer.

The invention can form stable support at two ends of the thread engagement, has the similar function of an angular contact ball bearing, prevents inclination, omits gears at two ends of a roller and inner gear rings positioned at two sides in a nut in the traditional planetary roller screw pair, further simplifies the traditional structure, has larger transmission ratio, is a new type in the transmission of the planetary roller screw, inherits the common advantages of strong bearing capacity, large rigidity, small abrasion and long service life of the planetary roller screw pair, can bear higher load under the same volume and weight due to simpler structure, and has the advantages of higher input rotating speed, smaller lead, larger reduction ratio and the like.

It is further preferred that the difference between the rollers is in the axial dimension between the extreme thread root in the middle section of the roller and the end surface of the roller, i.e. the value of X is different.

Further preferably, the thread on the screw rod is a single-end external thread with a lead angle, so that the processing is simpler.

Compared with the prior art, the invention has the beneficial effects that:

the invention can form stable support at two ends of the thread engagement, has the similar function of an angular contact ball bearing, prevents inclination, omits gears at two ends of a roller and inner gear rings positioned at two sides in a nut in the traditional planetary roller screw pair, further simplifies the traditional structure, has larger transmission ratio, is a new type in the transmission of the planetary roller screw, inherits the common advantages of strong bearing capacity, large rigidity, small abrasion and long service life of the planetary roller screw pair, can bear higher load under the same volume and weight due to simpler structure, and has the advantages of higher input rotating speed, smaller lead, larger reduction ratio and the like.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic view of the structure of the roller.

In the figure: 1. a lead screw; 2. a nut; 3. a roller; 4. a holder; 5. and a retainer ring.

Detailed Description

The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.

As shown in fig. 1 and 2, the differential planetary roller screw pair comprises a screw 1, a nut 2 and a plurality of rollers 3 arranged between the screw 1 and the nut 2, wherein the nut 2 is divided into three sections, the inner diameter of the middle section in the nut 2 is larger, no internal thread is arranged, and the inner diameters of the two ends of the middle section in the nut 2 are smaller than that of the middle section and are provided with internal threads;

each roller 3 is divided into three sections, the thread parameters of the roller 3 at the middle section are different from those of the parts at the two ends of the middle section of the roller 3, but the thread lead angles of the three sections of threads of the stud 3 are all zero, the diameter of the middle section of the roller 3 is larger, the diameters of the parts at the two ends of the middle section of the roller 3 are smaller than those of the middle section, the threads of the middle section of the roller 3 are meshed with the threads of the screw rod 1, the threads of the parts at the two ends of the middle section of the roller 3 are meshed with the internal threads of the nut 2, meanwhile, a gap is formed between the threads of the parts at the two ends of the middle section of the roller 3 and the threads of the screw rod 1, in addition, the;

the pitch between the nut 2, the roller 3 and the screw 1 is equal.

The number of the rollers 3 is even, the number of each roller 3 is two, the even rollers 3 are arranged between the screw rod 1 and the nut 2 at intervals, namely the two adjacent rollers 3 are different, two ends of each roller 3 are fixed by the retainer 4, and the retainer ring 5 is arranged on the outer side of the retainer 4.

The difference between the rollers 3 is that the axial dimension between the thread root at the extreme end of the middle section of the roller 3 and the end surface of the roller 3 is different, i.e. the value of X is different.

The thread on the screw rod 1 is a single-end external thread with a helix angle.

The working principle is as follows:

when the nut is assembled, the roller is placed between the screw rod and the nut, the external threads at the two ends of the roller are meshed with the two internal threads in the nut, the threads of the middle ring groove are meshed with the threads of the screw rod, and the two ends of the roller are fixed by the two retainers. Meanwhile, the screw pitches of the nut, the screw rod and the roller are equal, so that the relative displacement between the roller and the nut is zero, the end retainer is used for supporting a plurality of rollers, and generally, the screw rod of the invention performs positive transmission motion, namely, the rotary motion of the screw rod is converted into the linear motion of the nut along the axial direction.

In the description of the present invention, the terms "inside", "outside", "upper", "lower", "top", "bottom", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention but do not require that the present invention must be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.