Self-lubricating planetary roller screw rod

Abstract

The embodiment of the utility model discloses a self-lubricating planetary roller screw rod. The self-lubricating planetary roller screw rod comprises a screw rod; concave mounting grooves are formed in one end or two ends of the planetary nut assembly; the oil box is embedded in the mounting groove and fixed in the mounting groove through a locking piece, an oil storage cavity used for storing a lubricating agent is formed in the oil box, the oil box is provided with an oil guide piece in a matched mode, and the oil guide piece is used for guiding the lubricating agent in the oil storage cavity to the surface of the lead screw. According to the self-lubricating planetary roller lead screw, lubricant can be stably conveyed to the surface of the lead screw through the oil box, dynamic lubrication is formed, lubrication efficiency is improved, abrasion is reduced, meanwhile, the oil box is simple in structure, replaceable and convenient to install and maintain, and production cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of planetary ball screw pair, more particularly to a self-lubricating planetary roller screw. BACKGROUND

[0002] The planetary roller screw pair is widely used in high load and high precision mechanical transmission system due to its high load capacity and transmission efficiency. However, during its long-term operation, the relative movement between the roller and the screw thread will generate significant wear and friction heat, which requires high lubrication conditions. Usually, grease is filled in the nut to lubricate, but with the reciprocating movement of the screw pair, the grease will be gradually squeezed out or migrated, resulting in a decrease in lubrication effect, thus aggravating wear and shortening the service life. Therefore, in order to ensure the long-term stable operation of the screw pair, the grease needs to be replenished and maintained regularly.

[0003] To solve the above problems, the prior art proposes a scheme of setting a lubrication channel in the nut structure. For example, German patent DE102012212311A1 discloses a planetary screw transmission device, which is provided with a lubrication channel for injecting lubricant on the nut to supplement the lubricant during operation. However, this scheme requires additional machining of the nut, increasing the structural complexity and manufacturing cost, and there is still room for further improvement. SUMMARY

[0004] The utility model aims at solving one of the technical problems in the related art to some extent. Therefore, the utility model embodiment proposes a self-lubricating planetary roller screw, and the lubricant can be stably delivered to the surface of the screw by the oil box to form dynamic lubrication, improve the lubrication efficiency and reduce wear, and the oil box structure is simple and replaceable, facilitating installation and maintenance and reducing production cost.

[0005] The technical scheme adopted by the utility model is to provide a self-lubricating planetary roller screw, which comprises:

[0006] a screw rod;

[0007] a planetary nut assembly, one end or both ends of the planetary nut assembly being provided with a recessed mounting groove;

[0008] an oil box embedded in the mounting groove and fixed in the mounting groove by a locking member, the oil box being internally provided with an oil storage cavity for storing lubricant, and being provided with a lubricant guide member for guiding the lubricant in the oil storage cavity to the surface of the screw rod.

[0009] With the above structure, the lubricant can be continuously guided to the surface of the screw by the oil guiding piece from the oil storage cavity of the oil box, realizing dynamic lubrication of the contact part between the screw and the nut, significantly improving the lubrication efficiency and reducing the friction and wear. At the same time, since the oil box is detachably arranged in the mounting groove of the nut assembly and positioned and fixed by the locking piece, the installation and maintenance of the lubrication system are facilitated, and the nut body does not need to be complicatedly modified, thereby reducing the manufacturing cost.

[0010] In addition, the oil box structure is relatively independent, facilitating selection of oil boxes with different capacities or materials according to the use requirements, so as to realize optimization of the lubrication performance and structural adaptability. The oil guiding piece is used for delivering the lubricant to the surface of the screw for lubrication and dust removal, improving the reliability and service life of the overall system. Compared with the prior art of only providing a lubrication channel, the technical scheme has a more simple structure and more efficient lubrication, and is suitable for automatic lubrication application scenarios under long-term and high-frequency working conditions.

[0011] According to an embodiment of the present application, the planetary nut assembly comprises a nut, a gear ring, a retainer and a roller, wherein the retainer is used to keep the rollers uniformly distributed in the planetary nut, and the gear ring is engaged with the rollers to realize transmission; the planetary nut assembly and the screw are combined to form a planetary roller screw pair structure.

[0012] According to an embodiment of the present application, the roller has helical external teeth engaged with the gear ring; the roller is driven to rotate around its own axis and make planetary motion along the thread path when the screw rotates, so as to realize smooth transmission and efficient load transfer between the nut and the screw.

[0013] According to an embodiment of the present application, the retainer is of an annular structure and is provided with a plurality of matching holes, the matching holes are uniformly distributed around the center of the retainer, and the end of the roller is provided with a matching part rotatably matched with the matching hole; the matching part is used to guide and limit the roller during rotation and planetary motion, so as to ensure stable operation of the roller along the set path in the nut, effectively improving the transmission accuracy and service life.

[0014] According to an embodiment of the present application, the side wall of the mounting groove is provided with a through hole, the locking piece is threadedly connected with the through hole, and the inner end of the locking piece abuts against the oil box, so as to limit the movement of the oil box relative to the planetary nut assembly, prevent the oil box from loosening or falling out during operation, and ensure the stability and reliability of the lubrication system.

[0015] According to an embodiment of the present application, the planetary nut assembly further comprises a check ring, the check ring is installed on the gear ring, and is used to limit the movement of the retainer in the axial direction.

[0016] According to one embodiment of the present application, the installation groove is arranged on the gear ring.

[0017] According to one embodiment of the present application, a part of the oil guide extends to the inner ring area of the oil box in the radial direction, for contacting the outer surface of the screw rod.

[0018] According to one embodiment of the present application, the oil box comprises a shell and an end cover, and the shell is sealingly connected with the end cover to form an oil storage cavity for storing lubricant.

[0019] According to one embodiment of the present application, the end cover is provided with an oil filling port, and the oil filling port is provided with a detachable plug for closing or opening the oil filling port. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the drawings needed to be used in the following embodiment or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0021] Figure 1 It is a perspective view of the planetary roller screw in the embodiment of the present application.

[0022] Figure 2 It is a structural schematic view of the planetary roller screw in the embodiment of the present application.

[0023] Figure 3 It is a perspective view of the planetary nut in the embodiment of the present application.

[0024] Figure 4 It is a half-section perspective view of the planetary nut in the embodiment of the present application.

[0025] Figure 5 It is an explosion view of the planetary nut in the embodiment of the present application.

[0026] Figure 6 It is a connection schematic view of the roller and the gear ring in the embodiment of the present application.

[0027] Figure 7 It is a perspective view of the roller and the retainer in the embodiment of the present application.

[0028] Figure 8 It is a perspective view of the roller in the embodiment of the present application.

[0029] Figure 9 It is a perspective view of the oil box in the embodiment of the present application.

[0030] Figure 10 This is a schematic diagram of the oil box structure in an embodiment of this utility model.

[0031] Explanation of the labels in the diagram:

[0032] 1. Lead screw; 2. Nut; 3. Oil box; 4. Locking element; 5. Retaining ring; 6. Cage; 7. Gear ring; 8. Roller;

[0033] 21. Mounting slot; 22. Through hole;

[0034] 31. Outer casing; 32. End cap; 33. Plug; 34. Oil guide component;

[0035] 61. Mating hole;

[0036] 81. Fitting part; 82. External thread; 83. Helical external tooth. Detailed Implementation

[0037] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model. Example 1

[0038] like Figures 1-10 As shown, this embodiment discloses a self-lubricating planetary roller screw, comprising:

[0039] Lead screw 1;

[0040] A planetary nut assembly, wherein one or both ends of the planetary nut assembly are provided with recessed mounting grooves 21;

[0041] The oil box 3 is embedded in the mounting groove 21 and fixed in the mounting groove 21 by the locking member 4. The oil box 3 has an oil storage cavity for storing lubricant and is equipped with an oil guide member 34. The oil guide member 34 is used to guide the lubricant in the oil storage cavity to the surface of the lead screw 1.

[0042] Further, the screw rod 1 cooperates with the planetary nut assembly to form a complete planetary roller 8 screw rod 1 structure. In this embodiment, the planetary nut assembly extends in the axial direction of the screw rod 1 to form a recess structure, i.e., the mounting groove 21, for accommodating the oil box 3. Preferably, in this embodiment, the two ends of the planetary nut assembly are each provided with a mounting groove 21, and each is embedded with an oil box 3, so that continuous lubrication can be achieved in both directions of operation. The oil box 3 is provided with a closed oil storage cavity, which can store lubricant for a long time; the matching oil guide structure delivers the lubricant to the surface of the screw rod 1 through capillary action, so that the screw rod 1 is continuously lubricated during operation and simultaneously achieves a dustproof function.

[0043] In combination Figures 4 to 8 Further refinement is shown in the drawings: the planetary nut assembly is composed of multiple components, including the nut 2, the ring gear 7, the retainer 6, and a plurality of rollers 8. The retainer 6 is in a ring structure and is mainly used to uniformly distribute the rollers 8 in the axial direction and limit the movement range of the rollers 8, so that the rollers 8 always run stably; the ring gear 7 is engaged with the spiral external teeth 83 on the outer surface of the roller 8 to achieve transmission function. Each roller 8 is formed with a spiral tooth structure on the outer surface, which can reliably engage with the internal teeth of the ring gear 7. The retainer 6 is provided with a plurality of matching holes 61, which are uniformly arranged along the circumferential direction of the retainer 6, and are used to rotationally connect with the matching portions 81 at the ends of the rollers 8, so that the two ends of each roller 8 are matched with the hole positions on the two retainers 6.

[0044] Further, in this specific embodiment, the two annular retainers 6 are arranged in parallel along the axial direction of the screw rod 1 and are spaced apart from each other. Each retainer 6 is uniformly provided with ten matching holes 61, so that the two ends of the ten rollers 8 are rotationally matched with the corresponding hole positions on the two retainers 6, ensuring that the rollers 8 are uniformly stressed and run stably during rotation. The internal teeth of the ring gear 7 and the external spiral teeth of the roller 8 form a firm engagement relationship, wherein the spiral external teeth 83 on the surface of the roller 8 are formed by spiral machining and have excellent transmission efficiency and carrying capacity.

[0045] Further, in order to prevent the retainer 6 from moving uncontrollably in the axial direction, the planetary nut assembly is also provided with a stop ring 5 for limiting the position. The stop ring 5 is installed on the ring gear 7 and plays a role in stabilizing the position of the retainer 6 and limiting its axial sliding. At the same time, the recess structure for mounting the oil box 3 is also integrally provided on the ring gear 7 in this embodiment, which facilitates the accurate installation of the oil box 3 and the integrated design of the lubrication system.

[0046] In combination Figures 9 to 10As shown, the oil box 3 structure in the embodiment includes a shell 31 and an end cover 32, which are sealedly connected to jointly constitute a closed oil storage cavity for internally storing lubricant. Specifically, the shell 31 and the end cover 32 are precisely matched to ensure air and liquid tightness, thereby preventing lubricant leakage or external impurities from entering. The end cover 32 is provided with an oil filling port, which facilitates the addition of lubricant into the oil storage cavity during maintenance or use. To achieve sealing effect and convenient operation, the oil filling port is provided with a detachable plug 33, which can be opened or closed by the operator as needed, ensuring the efficiency of the oil filling operation and the cleanliness of the system operation.

[0047] Further explanation, in this embodiment, the shell 31 and the end cover 32 of the oil box 3 are both made of injection molding process, usually choose to have good sealing performance and chemical corrosion resistance of engineering plastics as raw material. The shell 31 and the end cover 32 are permanently connected by ultrasonic welding technology, the welding part is tight and firm, which ensures that there will be no looseness or leakage problem in the long-term operation of the oil box 3. The structure after welding is annular as a whole, which surrounds a stable and reliable oil storage cavity. The inner side wall of the shell 31 is provided with a notch for embedding the oil guide 34.

[0048] The oil guide 34 is preferably made of foam material, the main body of which is mainly placed inside the oil storage cavity to absorb the lubricant; part of which extends out through the above-mentioned notch and penetrates into the inner ring area of the oil box 3, directly contacting the outer surface of the lead screw 1. With the capillary structure characteristics of the foam, the lubricant can be slowly released to the surface of the lead screw 1 when it rotates, realizing continuous lubrication and dust prevention function.

[0049] Further combination Figure 5 As shown, the inner wall of the mounting groove 21 on the planetary nut assembly is provided with a through hole 22 structure, which provides a mounting position for the locking piece 4. The locking piece 4 is a bolt, the outer thread 82 of which is matched with the inner thread of the through hole 22. After being screwed, the inner end face of the locking piece 4 directly contacts and tightly fixes with the outer surface of the shell 31 of the oil box 3, so as to firmly limit the oil box 3 in the mounting groove 21, avoiding the loosening, displacement or even falling off of the oil box 3 due to vibration, rotation or lubricant disturbance during equipment operation. Through the structure design, not only the assembly stability between the oil box 3 and the planetary nut assembly is enhanced, but also the reliability and long-term working consistency of the whole lubricating system are significantly improved.

[0050] In the description of the utility model, need understanding is, the orientation or positional relation indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" is based on the orientation or positional relation shown in the drawings, only for the convenience of describing the utility model and simplifying the description, and is not to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore can not be understood as the limitation of the utility model.

[0051] In the utility model, unless another explicit provision and limitation, the first feature is "on" or "under" the second feature, can be the first and second features direct contact, or the first and second features indirect contact through intermediate medium.Moreover, the first feature can be "on", "above" and "on" the second feature, can be the first feature is directly above or obliquely above the second feature, or just indicate that the first feature horizontal height is higher than the second feature.The first feature can be "under", "below" and "under" the second feature, can be the first feature is directly below or obliquely below the second feature, or just indicate that the first feature horizontal height is less than the second feature.

[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 can not be understood as the limitation of the utility model, and the ordinary skilled in the art can change, modify, replace and change the above-mentioned embodiments within the scope of the utility model.

Claims

1. A self-lubricating planetary roller screw, characterized by, The utility model relates to a screw rod lubricating device, comprising: a screw rod; a planetary nut assembly provided with recessed mounting grooves at one end or both ends; an oil box embedded in the mounting grooves and fixed in the mounting grooves by locking members, the oil box is internally provided with an oil storage cavity for storing lubricant and is provided with oil guiding members for guiding the lubricant in the oil storage cavity to the surface of the screw rod.

2. The self-lubricating planetary roller screw of claim 1, wherein: The planetary nut assembly comprises a nut, a gear ring, a retainer, and rollers, wherein the retainer is used to uniformly distribute the rollers in the planetary nut, and the gear ring is engaged with the rollers.

3. The self-lubricating planetary roller screw of claim 2, wherein: The rollers have helical external teeth engaged with the gear ring.

4. The self-lubricating planetary roller screw of claim 2, wherein: The retainer has an annular structure and is provided with a plurality of matching holes uniformly distributed around the center of the retainer, and the end of the roller is provided with a matching part rotatably matched with the matching hole.

5. The self-lubricating planetary roller screw of claim 1, wherein: The side wall of the mounting groove is provided with a through hole, the locking member is threadedly connected with the through hole, and the inner end of the locking member abuts against the oil box to limit the movement of the oil box relative to the planetary nut assembly.

6. The self-lubricating planetary roller screw of claim 2, wherein: The planetary nut assembly further comprises a check ring installed on the gear ring to limit the movement of the retainer in the axial direction.

7. A self-lubricating planetary roller screw as defined in claim 6, wherein: The mounting groove is arranged on the gear ring.

8. The self-lubricating planetary roller screw of claim 1, wherein: Part of the oil guiding member extends radially to the inner ring area of the oil box to contact the outer surface of the screw rod.

9. The self-lubricating planetary roller screw of claim 1, wherein: The oil box comprises a shell and an end cover, and the shell and the end cover are sealingly connected to form an oil storage cavity for storing lubricant.

10. The self-lubricating planetary roller screw of claim 9, wherein: The end cover is provided with an oil inlet, and the oil inlet is provided with a detachable plug for closing or opening the oil inlet.

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