Planetary roller screw

Abstract

The embodiment of the utility model discloses a planetary roller lead screw which comprises a lead screw body and a nut, and the nut comprises a body, planetary rollers, a planetary support and a gear ring. Wherein the screw rod and / or the nut are / is integrally made of a ceramic material; or at least one of the body, the planetary pin roller, the planetary support and the gear ring in the nut is made of ceramic materials. The utility model provides a planetary roller screw which can effectively improve the corrosion resistance and the lubrication-free capacity of the whole structure and expand the application scenes of the planetary roller screw in special environments.

Description

TECHNICAL FIELD

[0001] The utility model relates to ball screw technical field more specifically, relate to a kind of planetary roller screw. BACKGROUND

[0002] Planetary roller screw is a kind of high-performance transmission mechanism widely used in numerical control machine tool, high-precision automation equipment and aerospace fields etc..The structure is rolled transmission between nut and screw by multiple rollers, realizes high efficiency, high bearing, low friction linear motion, with the advantages of high positioning accuracy, fast response speed, strong load capacity etc..The common planetary roller screw on market mainly uses metal material to manufacture, for example, steel, stainless steel etc..Although metal material has good mechanical properties and processing performance, in some special use environment, there are still following technical problems:

[0003] 1. Poor corrosion resistance: metal material is easily affected by humidity, acid, alkali or corrosive gas, leading to surface rust, pitting, reducing the service life and stability of screw pair.

[0004] 2. High lubrication dependence: traditional metal planetary roller screw usually relies on lubricant to reduce friction and wear, if lubrication is insufficient or environment is inconvenient to supplement lubricant, it is easy to cause dry friction, heating, wear and tear, etc. SUMMARY

[0005] The utility model aims at solving one of the technical problems in the related art to some extent.For this purpose, the utility model embodiment proposes a kind of planetary roller screw, can effectively improve the corrosion resistance and lubrication-free capacity of overall structure, expand its application scene in special environment.

[0006] The technical scheme adopted by the utility model is: provide a kind of planetary roller screw, including screw rod and nut, the nut includes body, planetary roller, planet carrier and gear ring;

[0007] Wherein, the screw rod and / or the nut is ceramic material as a whole;Or, at least one of the body, planetary roller, planet carrier and gear ring in the nut is ceramic material.

[0008] With the above structure, since the ceramic material has excellent corrosion resistance, wear resistance, high hardness and low friction coefficient, the reliability and durability of the planetary roller screw in harsh environments can be significantly improved. On the one hand, the ceramic element is not easy to rust or degrade in high humidity, high salt, high temperature, strong acid and alkali working environment, thereby prolonging the service life of the screw pair. On the other hand, the ceramic material has good lubrication performance on its surface, even in the absence of lubricant or completely no lubrication working condition, it can still maintain low friction loss and reduce the wear between rolling elements. In addition, the ceramic has excellent electrical insulation and non-magnetic properties, which also makes the structure applicable to occasions with strict requirements on electromagnetic interference, such as semiconductor manufacturing equipment, medical imaging equipment, vacuum chamber system and other high-precision and special-purpose devices.

[0009] In summary, the utility model introduces ceramic material in the planetary roller screw, breaks through the bottleneck of traditional metal structure in corrosion resistance, lubrication dependence and special working conditions, has the advantages of novel structure, strong adaptability, reliable operation and the like, and has good engineering application prospect and industrialization value.

[0010] According to an embodiment of the utility model, the gear ring is provided with a stepped surface and an inner groove for mounting a snap spring, and the planetary support is movably arranged between the stepped surface and the snap spring; the snap spring is assembled in the inner groove and limits the planetary support in the axial direction to avoid axial movement or deviation during operation, ensuring uniform engagement and stable transmission of the roller between the screw rod and the nut.

[0011] According to an embodiment of the utility model, the planetary roller screw further comprises a lubricating assembly, which is arranged at the end of the body.

[0012] According to an embodiment of the utility model, the body is connected with a locking screw, and the inner end of the locking screw abuts against the lubricating assembly to limit the separation of the lubricating assembly relative to the body.

[0013] According to an embodiment of the utility model, a first through hole is arranged on the side wall of the body, and the locking screw is threadedly connected with the first through hole.

[0014] According to an embodiment of the utility model, a second through hole is arranged on the gear ring, and the locking screw is arranged in the second through hole.

[0015] According to one embodiment of the utility model, the lubricating assembly comprises a shell and an oil guide, the shell is internally provided with an oil storage cavity, one part of the oil guide is arranged in the oil storage cavity, another part penetrates out of the shell and is in contact with the outer surface of the screw rod, wherein the oil guide is a foam, felt pad or woven fiber with capillary penetration performance, one end of the oil guide is arranged in the oil storage cavity, and the other end is stretched out and adhered to the surface of the screw rod, the continuous supply of lubricant is realized by means of the shearing force and capillary guiding effect formed in the rotation process of the screw rod, the friction and wear are effectively reduced, and the service life of the screw pair is prolonged.

[0016] According to one embodiment of the utility model, the shell comprises an outer shell and an end cover, and the outer shell and the end cover are sealingly connected to form the oil storage cavity.

[0017] According to one embodiment of the utility model, the outer shell is provided with an oil injection port, and the oil injection port is provided with a plug for closing or opening.

[0018] According to one embodiment of the utility model, the gear ring is provided with a fastening hole, and the body is connected with the gear ring through a fastener. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced, and obviously, the drawings in the following description can also be used to obtain other drawings without creative labor for the ordinary skilled in the art.

[0020] Figure 1 It is a perspective view of the planetary roller screw in the embodiment of the utility model.

[0021] Figure 2 It is a perspective view of the nut and the lubricating assembly in the embodiment of the utility model.

[0022] Figure 3 It is an exploded view of the nut and the lubricating assembly in the embodiment of the utility model.

[0023] Figure 4 It is a half-section perspective view of the nut and the lubricating assembly in the embodiment of the utility model.

[0024] Figure 5 It is an exploded view of the nut in the embodiment of the utility model.

[0025] Figure 6 It is a perspective view of the gear ring in the embodiment of the utility model.

[0026] Figure 7 It is a perspective view of the gear ring and the lubricating assembly in the embodiment of the utility model.

[0027] Figure 8 Structure diagram of the planetary roller, the planetary support and the gear ring in the embodiment of the utility model.

[0028] Figure 9 Connection diagram of the planetary roller and the planetary support in the embodiment of the utility model.

[0029] Figure 10 Three-dimensional view of the planetary roller in the embodiment of the utility model.

[0030] Figure 11 Three-dimensional view of the lubricating assembly in the embodiment of the utility model.

[0031] Figure 12 Exploded view of the lubricating assembly in the embodiment of the utility model.

[0032] Mark explanation in the drawing:

[0033] 10, screw rod; 20, nut; 30, lubricating assembly;

[0034] 21, body; 22, planetary roller; 23, planetary support; 24, gear ring; 25, clamp spring; 26, locking screw; 27, fastener;

[0035] 21a, first through hole;

[0036] 22a, external thread; 22b, external tooth;

[0037] 24a, internal tooth; 24b, step surface; 24c, internal groove; 24d, second through hole; 24e, fastening hole;

[0038] 31, shell; 32, end cover; 33, oil guide; 34, plug. DETAILED DESCRIPTION

[0039] The embodiments of the utility model are described in detail below, and examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary, only for explaining the utility model, and cannot be understood as limiting the utility model. Embodiment one

[0040] As shown in the drawing, Figures 1-12 In the embodiment, a planetary roller 22 screw rod is disclosed, which comprises a screw rod 10 and a nut 20, the nut 20 comprises a body 21, a planetary roller 22, a planetary support 23 and a gear ring 24;

[0041] The screw rod 10 and / or the nut 20 are made of ceramic material as a whole.

[0042] In terms of material selection, the screw rod 10 and / or the nut 20 can be made of ceramic material as a whole, and high-performance zirconia ceramic material is particularly preferred. In the preferred embodiment of the present embodiment, the screw rod 10 and the nut 20 are both made of zirconia ceramic and are manufactured by precise ceramic forming process. Specifically, the preparation process of the zirconia ceramic part can include the following steps: first, high-purity zirconia powder is ball milled and dispersed to ensure that the powder particles are refined and uniform; then a blank is made by slurry casting, dry pressing, injection molding or isostatic pressing; then low-temperature degassing and high-temperature sintering treatment is performed, and the sintering temperature is usually controlled between 1400°C and 1600°C to realize the densification of the ceramic; finally, high-precision size and excellent surface quality of the ceramic part can be achieved through numerical control grinding, polishing and other finishing processes.

[0043] In other alternative embodiments, only the screw rod 10 can be designed as ceramic material, while the nut 20 structure of traditional metal or composite material is retained; or according to actual application requirements, one or more of the body 21, planetary roller 22, planetary carrier 23 or gear ring 24 in the nut 20 is replaced by ceramic material. The above-mentioned diversified material combination not only improves the adaptability of the planetary roller 22 screw in high load, high temperature, strong corrosion and other complex working conditions, but also makes the structure have higher engineering flexibility and practical value.

[0044] Further, as shown in Figure 10 In the present embodiment, the planetary roller 22 is provided with an external thread 22a and an external tooth 22b, and the external tooth 22b is engaged with the internal tooth 24a on the gear ring 24.

[0045] Specifically, as shown in Figure 6 In the present embodiment, the structure design of the gear ring 24 includes a stepped surface 24b for positioning and an inner groove 24c along the inner diameter of the gear ring 24 for mounting the snap spring 25. The planetary carrier 23 is rotatably arranged between the stepped surface 24b and the snap spring 25, forming a controllable clearance structure. The snap spring 25 is reliably mounted in the inner groove 24c of the gear ring 24 and exerts a limiting action on the planetary carrier 23 in the axial direction, thereby effectively preventing the planetary carrier 23 from moving, slipping or position offsetting in the axial direction after assembly or during operation.

[0046] Further, as shown in Figures 7-8As shown, the planetary roller 22 screw further comprises a lubricating assembly 30 for continuously lubricating the meshing area between the screw rod 10 and the nut 20, thereby reducing friction, prolonging service life and improving smooth operation. The lubricating assembly 30 is arranged at the end of the body 21 of the nut 20, specifically at the upper side of the snap spring 25, i.e. at the side of the snap spring 25 away from the stepped surface 24b, which ensures the lubricating function while not affecting the mobility of the planetary support 23 and the movement path of the roller.

[0047] To prevent the lubricating assembly 30 from loosening during operation due to vibration or other external forces, the body 21 is further provided with a locking screw 26 for reliable fixation of the lubricating assembly 30. Specifically, the inner end of the locking screw 26 abuts against the lubricating assembly 30, limiting the movement or disengagement of the lubricating assembly 30 relative to the body 21 by applying axial force. The locking screw 26 is installed in the first through hole 21a provided on the side wall of the body 21 by threading, forming a stable connection; at the same time, the gear ring 24 is also provided with a second through hole 24d for the locking screw 26 to pass through, thereby ensuring that the locking screw 26 can pass through the gear ring 24 structure during installation, achieving effective connection and positioning with the body 21.

[0048] Specifically, in combination with Figures 11-12 As shown, in this embodiment, the lubricating assembly 30 comprises a shell and an oil guide 33 for realizing continuous oil supply and lubrication of the surface of the screw rod 10. The shell is internally provided with an oil storage cavity for storing lubricant to ensure the continuous lubricating ability of the system during long-term operation. The main body of the oil guide 33 is embedded in the oil storage cavity, and the other part protrudes out of the outer wall of the shell and directly contacts the outer surface of the screw rod 10. The oil guide 33 is made of a material with good capillary transport performance, which can stably and slowly transport the lubricant in the oil storage cavity to the working surface of the screw rod 10 by capillary effect, realizing automatic lubrication effect and avoiding the phenomenon of increased wear or jamming due to lack of oil.

[0049] Further, the shell comprises an outer shell 31 and an end cover 32, which are sealed and formed in a sealed manner between them, forming a sealed oil storage cavity to effectively prevent leakage or evaporation of the lubricant. To facilitate the replenishment and replacement of the lubricant, an oil inlet is provided on the outer shell 31, which is provided with a detachable plug 34 for opening during oil injection and maintenance, and closing during normal use to ensure the sealing and safety of the lubricating system. The gear ring 24 is pre-provided with a plurality of fastening holes 24e, and the body 21 is firmly connected to the gear ring 24 by fastening members 27.

[0050] In the description of the utility model, need understanding is, the term "center" "longitudinal" "lateral" "length" "width" "thickness" "upper" "lower" "front" "back" "left" "right" "vertical" "horizontal" "top" "bottom" "inner" "outer" "clockwise" "counterclockwise" "axial" "radial" "circumferential" and so on the orientation or positional relationship indicated in the drawing is based on the orientation or positional relationship shown in the drawing, just is for the convenience of describing the utility model and simplifying the description, and is not the device or element indicated or implied must have a particular orientation, with a particular orientation configuration and operation, therefore can not be understood as the restriction of the utility model.

[0051] In the utility model, unless another explicit provision and limitation, the term "installation" "connection" "connect" "fix" and so on the term should do broad sense understanding, for example, can be fixed connection, also can be detachable connection, or integrated;Can be mechanical connection, also can be electric connection or each other can communicate;Can be directly connected, also can be indirectly connected through intermediate medium, can be the communication or the interaction relationship of two elements of two elements inside, unless another explicit limitation.For ordinary skilled person in the art, can understand the concrete meaning of the above-mentioned term in the utility model according to the specific circumstances.

[0052] Although the embodiments of the utility model have been shown and described above, it can be understood that the above-mentioned embodiments are exemplary, and cannot be understood as the limitation of the utility model, and ordinary skilled person in the art can change, modify, replace and change the above-mentioned embodiments within the scope of the utility model.

Claims

1. A planetary roller screw characterized by: The screw rod and the nut comprise a body, planetary rollers, a planetary support and a gear ring. The screw rod and / or the nut are made of ceramic material, or at least one of the body, the planetary rollers, the planetary support and the gear ring of the nut is made of ceramic material.

2. A planetary roller screw as claimed in claim 1, characterized in that: The gear ring is provided with a stepped surface and an inner groove for mounting a snap spring, and the planetary support is movably arranged between the stepped surface and the snap spring.

3. A planetary roller screw as claimed in claim 1, characterized in that: A lubricating assembly is further arranged at an end of the body.

4. A planetary roller screw as claimed in claim 3, characterized in that: A locking screw is connected to the body, and an inner end of the locking screw abuts against the lubricating assembly to limit the separation of the lubricating assembly from the body.

5. A planetary roller screw as claimed in claim 4, characterized in that: A first through hole is arranged on a side wall of the body, and the locking screw is threadedly connected to the first through hole.

6. A planetary roller screw as claimed in claim 5, characterized in that: A second through hole is arranged on the gear ring, and the locking screw is arranged in the second through hole.

7. A planetary roller screw as claimed in claim 3, characterized in that: The lubricating assembly comprises a shell and an oil guide, an inner part of the shell is provided with an oil storage cavity, and a part of the oil guide is arranged in the oil storage cavity and another part of the oil guide is arranged outside the shell and in contact with an outer surface of the screw rod.

8. A planetary roller screw as claimed in claim 7, characterized in that: The shell comprises an outer shell and an end cover, and the outer shell and the end cover are sealingly connected to form the oil storage cavity.

9. A planetary roller screw as claimed in claim 8, characterized in that: An oil injection port is arranged on the outer shell, and a plug is arranged on the oil injection port to close or open the oil injection port.

10. A planetary roller screw as claimed in claim 1, characterized in that: The gear ring is provided with a fastening hole, and the body and the gear ring are connected by a fastener.

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