JP4834063B2 - Ball screw with lubrication device - Google Patents

Description

  The present invention relates to a ball screw provided with a lubrication device, and more particularly to a lubrication device filled with grease.

  In the first place, a conventional ball screw is mainly formed by tightening a screw shaft through a ball so that the nut can rotate freely, and slides relative to the nut and screw shaft using the rotatable ball. be able to. With excellent smoothness and accuracy, it is widely used on equipment that needs to move precisely, for example, in each microfabrication or semiconductor process equipment, so the lubrication of the spiral rail is extremely important is there. However, if the ball screw is not lubricated for a long time, the friction between the nut and the screw is increased and the wear of the ball screw is accelerated.

  Therefore, in order to effectively reduce wear due to friction with the ball screw, the conventional ball screw lubrication system is mainly divided into two types. One of them is that a lubricating system is applied to both ends of the nut to accumulate the lubricating oil in the lubricating system. Further, the lubricating oil is absorbed by the oil absorption material and then applied directly onto the surface of the screw to lubricate the screw on the screw. Let The other is manufactured using oil-filled material on the scraper at both ends of the nut, and the oil-filled material is used to lubricate the helical groove of the bolus screw so that it is in direct contact with the surface of the ball screw. .

  However, the conventional self-lubricating ball screw is externally mounted and attached on the nut, and the inside of the accessory is filled with felt fully absorbed by the grease, so the ball screw is rotated relative to the nut. When the felt is applied, grease is applied to the spiral groove of the ball screw to produce a lubricating effect. However, the usage conditions required in many clean rooms in the electronic semiconductor industry are that only grease can be used as a lubricant in the above-described lubrication system. However, since grease is liquid and easily generates particles, it cannot be used in an environment where cleanliness is important, such as a clean room in the electronic semiconductor industry. For this reason, it is impossible to use a conventional design in many electronic semiconductor industry manufacturing processes.

  In order to solve the above-mentioned problem, as disclosed in US Pat. No. 5,782,135, the lubrication method disclosed in FIG. 1 uses a fixed lubrication material (for example, disulfide) between the rolling bodies 31. A spacing ball 32 made of molybdenum, gold, silver, lead, PTFE, or the like will be installed. However, during the operation of the ball screw, wear between the spacing ball 32 and the rolling body 31 occurs, and the dust between the ball screw, the nut, and the rolling body 31 is supplemented with scraps from the wear. However, this technique has the following problems in the technique that achieves a lubricating effect by friction between the rolling element 31 and the spacing balls 32.

1. When the interval ball is worn away, the lubricating effect is completely lost, and when the distance ball is reduced to a certain size, the ball is caught and the normal operation of the rolling body is hindered.
2. When the interval ball is replenished as a lubricant, the replenishment efficiency is difficult to be constant, and the service life of the ball screw due to insufficient lubrication is shortened.

In addition, if grease is used instead of lubricating oil, it can be applied to usage environments that place importance on cleanliness, such as clean rooms in the electronic semiconductor industry. However, all the conventional lubrication devices provide power from the outside to push the grease to the inside of the ball screw (because the fluidity of grease is not so high, it is necessary to provide power from the outside) Basic accessories are more than all of the above-mentioned lubrication devices, and more space is required, and the cost is higher, so there is a need for further improvement.
US Patent No. 5,782,135

  Based on the above-mentioned problems of the prior art, the present inventor was able to devise an invention that can surely achieve the object of the following invention after repeated research and improvement.

  That is, the present invention mainly lubricates the ball screw with grease, and the lubrication device filled with grease achieves a lubrication effect by sufficiently transmitting the grease to the ball screw without providing power from the outside. The purpose is to be able to.

  Next, an object of the present invention is to enable the user to easily observe the decrease state of the grease, so that the addition time of the grease can be accurately grasped to prevent insufficient lubrication.

  In order to achieve the above object, a ball screw provided with a lubricating device of the present invention includes a screw shaft, a nut, a plurality of rolling elements, a reflux element, and a lubricating device.

  The screw shaft is provided with a spiral rotation groove on its outer edge and a guide groove parallel to the center line of the screw.

  The nut is provided with a perforation and a rotating tank is provided at the inner edge of the perforation so as to face the rotating groove, and the rotating groove and the rotating tank constitute a load path. A first fixed end is installed at one end of the nut, and a first sealing material is installed on the end surface of the first fixed end.

  The plurality of rolling elements are accommodated in the load path.

  The reflux element is mounted on the nut and can provide circulating reflux of the rolling element.

The lubrication apparatus includes a sleeve and a guide member, and the sleeve includes a second fixed end, a receiving hole, and a first through hole. The second fixed end is fixed together with the first fixed end (the alignment method is tight alignment, screws are installed at both ends and tightened together, fixed using pins or rivets, or bonded together To fix the sleeve to the end of the nut. The accommodation hole is provided for installation of the guide member, and the accommodation hole installs a second sealing material with respect to the guide member. The first sealing material and the second sealing material are in close contact with both end faces of the guide member, and can prevent the grease from overflowing from the lubricating device. The first through hole is for communicating with the accommodation hole and penetrating the screw shaft. Further, the guide member, the second through hole and a helical portion installed, the second through hole are provided to penetrate through the screw shaft, and for mating with each other and the guide groove in the second inner edge The fixed portion is provided, and a spiral groove is formed between the spiral portions. An oil discharge hole (it is possible to install an oil discharge hole only at one end) at both ends of the spiral groove extending in a spiral shape , and the spiral groove is closed by the accommodation hole of the sleeve. Constructs a spiral guideway. The end face of the receiving hole and the end face of the nut constrain the movement of the guide member in the axial direction by installing the guide member in the space of the receiving hole between these end faces (the guide member is connected to the nut). Axial movement in sync.)

  In addition, grease is filled in the guide way, and when the ball screw is operated (the lubricating device of the present invention is applied to a ball screw that drives a nut by a screw shaft), the sleeve is tightened to the nut. Therefore, the sleeve does not rotate but moves in the axial direction according to the nut. The guide member rotates in synchronism with the screw shaft by the fixing portion and the guide groove of the screw shaft, and rotates relative to the sleeve to move axially with the nut.

  Finally, during ball screw operation, it can be understood from the law of inertia or fluid dynamics that the guide member rotates with the screw shaft. The grease in the guide way advances along the guide way, and pressure is generated when the grease flows to the end of the guide way. Grease is transmitted to the ball screw from the oil discharge holes provided at both ends of the guideway by the pressure, and the flow rate of the grease is determined by the size of the diameter of the oil discharge hole. Thereby, the purpose of lubrication can be achieved.

  In order to clearly describe the features of the embodiments of the present invention, it will be described below that the present invention has an inventive step or practicality over the prior art.

1. According to the present invention, grease can be transmitted onto the ball screw by interlocking the guide member with the screw shaft without providing a power source outside.
2. The lubricating device of the present invention has a simple structure and can be manufactured by a mold. Can be produced in large quantities.
3. The lubrication apparatus of the present invention can cope with any environment by filling with grease, and the environmental applicability is extremely high.

  To further understand the features and technical contents of the present invention, reference can be made to the description of the implementation method according to the present invention and the drawings. However, the implementation method, drawings, and the like are merely used for explanation or reference, and do not limit the present invention.

  First, the first embodiment of the present invention relates to a ball screw provided with a lubricating device, as shown in FIGS. 1, 2, 3A, 3B, and 4. Is. The ball screw provided with the lubricating device includes a screw shaft 1, a nut 2, a plurality of rolling elements X, a reflux element, and a lubricating device 3.

  The screw shaft 1 is provided with a spiral rotation groove 11 on the outer edge thereof and a guide groove 12 parallel to the center line of the screw 1.

  The nut 2 has a perforation 21 and is provided with a rotation tank 211 facing the rotation groove 11 at the inner edge of the perforation 21, and the rotation groove 11 and the rotation tank 211 constitute a load path. A first fixed end 22 is provided at one end of the nut 2, and a first sealing member 23 is provided on the end surface of the nut on the same side of the first fixed end 22, and the first sealing member 23 is a guide member 32. Install against the end face of

  The plurality of rolling bodies X are accommodated in the load path.

  The reflux element (not shown) is mounted on the nut 2 and provides circulation reflux of the rolling element X.

  The lubricating device 3 includes a sleeve 31 and a guide member 32, and the sleeve 31 includes a second fixed end 312, a receiving hole 311, and a first through hole 314. The sleeve 31 is fixed to the end of the nut 2 by fixing the second fixed end 312 together with the first fixed end 22. The accommodation hole 311 is provided for the installation of the guide member 32, and the end surface of the accommodation hole 311 with respect to the guide member 32 is provided with a second sealing material 313, and the first sealing material 23 and the second sealing material 313 are guided. The grease is prevented from overflowing from the lubricating device 3 in close contact with both end faces of the member 32. The first through hole 314 communicates with the accommodation hole 311 to provide the insertion of the screw shaft 1. The guide member 314 is provided with a second through hole 323 and a spiral portion 321, and the second through hole 323 is provided for insertion of the screw shaft 1 and guided to the inner edge of the second through hole 323. A fixing portion 323 that fits with the groove 12 is provided, and a spiral groove 3211 is formed between the spiral portions 321. An oil discharge hole 322 (or an oil discharge hole 322 can be opened only at one end) is provided at both ends of the spiral groove 3211, and the spiral groove 3211 is a guide that is a closed spiral with the accommodation hole 311 of the sleeve 31. A way 60 is formed. The accommodation hole 311 and the end surface of the nut 2 form a space that restrains the movement of the guide member 32 in the axial direction (the guide member moves in the axial direction in synchronization with the nut).

  In the second embodiment of the present invention, as shown in FIGS. 5, 6, 7A, 7B, and 8, the nut screw provided with the lubricating device of the present invention includes a screw shaft 1, a nut 2, and a plurality of nut screws. Rolling element X, a reflux element (not shown), and a lubricating device 3A.

  The screw shaft 1 is provided with a rotating groove 11 whose outer edge is spiral and a guide groove 12 parallel to the center line.

  The nut 2 has a perforation 21, and an inner edge of the perforation 21 is provided with a rotation tank 211 corresponding to the rotation groove 11, and constitutes a load path composed of the rotation groove 11 and the rotation tank 211 and one end thereof. Is provided with a first fixed end 22.

  The plurality of rolling bodies X are accommodated in the load path.

  A reflux element is attached on the nut and circulates and refluxes the plurality of rolling elements.

The lubricating device 3A includes a sleeve 31A, a guide member 32A, and an outer cover 33A. The sleeve 31A is provided with a second fixed end 312A, a third fixed end 315A, a receiving hole 311A, and a first through hole 314A. The second fixed end 312A is fixed together with the first fixed end 22. As a result, the sleeve 31 </ b> A is fixed to the end of the nut 2. The accommodation hole 311A is for installing the guide member 32A. In addition, the end surface of the accommodation hole 311A corresponding to the guide member 32A is provided with a first sealing member 313A, and the first through hole 314A communicates with the accommodation hole 311A to insert the screw shaft 1 therein. provide. The guide member 32A is provided with a second through hole 323A and a spiral portion 321A, and the second through hole 323A is provided for insertion of the screw shaft 1. In addition, a fixing portion 3231A that fits with the guide groove 12 is provided at the inner edge of the second through hole 323A, a spiral groove 3211A is formed between the spiral portions 321A, and oil discharge holes are formed at both ends of the spiral groove 3211A. 322A is opened (or an oil outlet hole 322A can be provided only at one end), and a guideway 60 having a closed spiral is formed from the spiral groove 3211A and the accommodation hole of the sleeve 31A. A fourth fixed end 333A to be fitted with the third fixed end 315A is installed on the outer cover 33A , and the fourth fixed end 333A and the third fixed end 315A are coupled and fixed, thereby the outer cover 33A. Covers the end of the sleeve 31A and opens a third through hole 331A for inserting the screw shaft 1. Further, the outer cover 33A and the accommodation hole 311A form a space for restraining the movement of the guide member 32A in the axial direction (the movement of the guide member 32A and the nut 2 in the axial direction in synchronization), and the end face of the guide member 32A. The second sealing material 332A is provided at a position corresponding to the above, and the first sealing material 313A and the second sealing material 332A are in close contact with both end surfaces of the guide member 32A to prevent the grease from overflowing from the lubricating device. Can do.

  As described above, both embodiments of the present invention have been described. As described below, the lubricating device of the present invention is operated in combination with the ball screw so that the grease filled in the lubricating device is applied to the ball screw. Explain whether to transmit.

  First, the grease is filled in the guide way 60 through the oil supply hole 316 (316A) provided in the sleeve, and then the oil supply hole 316 (316A) is sealed with the oil plug 4. During the operation of the ball screw (the lubricating device 3 (3A) of the present invention is applied to the ball screw shaft in which the screw shaft 1 drives the nut 2), the sleeve 31 (31A) is fixed to the nut 2 so that the sleeve 31 (31 A) does not rotate, but moves in the axial direction according to the nut 2. The guide member 32 (32A) is fixed by the fixing portion 3231 (3231A) and the guide groove 12 of the screw shaft 1, and the guide member 32 (32A) rotates in synchronization with the screw shaft 1 to the sleeve 31 (31A). In addition to rotating with respect to the nut 2, an axial movement with the nut 2 is performed.

  Finally, since the guide member 32 (32A) rotates with the screw shaft 1 during ball screw operation, the grease in the guide way 60 follows the guide way as understood by the law of inertia or fluid dynamics. As grease moves forward to the end of the guideway, pressure is generated. The grease is transmitted to the ball screw from the oil discharge holes 322 (322A) provided at both ends of the guideway 60 by the pressure, and the flow rate of the grease is determined by the diameter of the oil discharge holes 322 (322A). The purpose of lubrication can be achieved.

  In conclusion, the present invention can solve the limitation of use due to the environment in the conventional lubrication system, and at the same time, the grease can flow into the ball screw without borrowing power from the outside due to the characteristic of the spiral principle. However, since the conventional technology can simplify the complicated structure of lubricating the lubricating device with grease, it is doubtful that the present invention already has “industrial applicability”. Neither is it disclosed in the publications before the filing of the technical features disclosed in this example, nor is it used for publication, and not only has the fact that the effect is enhanced, Since the enhancement of the additional effect cannot be overlooked, the present invention meets the requirements as patents for both “novelty” and “inventive step”. We expect to be permitted.

  Further, the disclosure of the above-described embodiments is for explaining the present invention, and does not limit the present invention. Any change such as a numerical change or replacement of an equivalent element is within the scope of the present invention. It belongs to.

It is a three-dimensional view of the ball screw provided with the lubricating device of the 1st Example in this invention. It is an exploded view of the lubricating device of the 1st Example in the present invention. It is a side view of the guide member of the 1st example in the present invention. It is the figure seen from the B direction of FIG. 3A. It is sectional drawing of the AA line of FIG. It is a three-dimensional view of the ball screw provided with the lubricating device of the 2nd Example in this invention. It is an exploded view of the lubricating device of the 2nd Example in the present invention. It is a side view of the guide member of the 2nd example in the present invention. It is the figure seen from the B direction of FIG. 7A. It is sectional drawing of the AA line of FIG.

Explanation of symbols

<Conventional technology>
DESCRIPTION OF SYMBOLS 1 Ball screw 11 Rotating groove 12 Guide groove 2 Nut 21 Perforation 211 Rotating tank 22 1st fixed end 23 1st sealing material 60 Guideway X Rolling body 4 Oil plug <1st Example>
DESCRIPTION OF SYMBOLS 3 Lubricating device 31 Sleeve 311 Housing hole 312 2nd fixed end 313 2nd sealing material 314 1st through-hole 316 Oil supply hole 32 Guide member 321 Spiral part 3211 Spiral groove 322 Oil discharge hole 323 2nd through-hole 3231 fixation Part <Second Example>
3A Lubricating device 31A Sleeve 311A Housing hole 312A Second fixed end 313A First sealing material 314A First through hole 315A Third fixed end 316A Oil filling hole 32A Guide member 321A Spiral part 3211A Spiral groove 322A Oil discharge hole 323A First 2 through-hole 3231A fixing portion 33A outer cover 331A third through-hole 332A second sealing material 333A fourth fixed end

Claims (5)

A screw shaft (1) having a spiral rotating groove (11) and a guide groove (12) installed on the outer edge;
Perforation (21) is opened, the nut (2) to the rotatable tub (211) is provided corresponding to the rotary groove on the inner edge of the perforations (21) (11),
A plurality of rolling elements (X) accommodated in a load path comprising the rotating groove (11) and the rotating tub (211) ;
A reflux element mounted on the nut (2) for circulating and refluxing the plurality of rolling elements (X) ;
Includes a sleeve (31) and guide member (32), the sleeve (31) is fixed to the end of the nut (2), the axial movement is accompanied with the rotation of the nut (2), the An accommodation hole (311) for installing the guide member (32) is opened in the sleeve (31) , and a second through hole (323) and a spiral portion (321) are provided in the guide member (32) . , the second hole (323) is for inserted the screw shaft (1), further, fitting together with said guide groove in the inner edge of the second hole (323) (12) fixing portion for engagement (3231) is installed, the helical portion forming a spiral groove (3211) between the (321), also on the end portion in a direction extending helically in said spiral groove (3211) opened Deyuana (322), wherein the said spiral groove (3211) sleeve (3 Ball screw with a lubricating apparatus characterized by constituting the helical guideway (60) by accommodating hole and (311) of). The end face of the accommodation hole (311) and the end face of the nut (2) are arranged in the space of the accommodation hole (311) between the end face of the accommodation hole (311) and the end face of the nut. by installing, the guide member (32) a ball screw provided with a lubricating system according to claim 1, wherein that you have adapted to restrain in order to exercise the axial direction together with the nut (2). A screw shaft (1) having a spiral rotating groove (11) and a guide groove (12) installed on the outer edge;
Perforation (21) is opened, the nut (2) to the rotatable tub (211) is provided corresponding to the rotary groove on the inner edge of the perforation (21) (11),
A plurality of rolling elements (X) accommodated in a load path comprising the rotating groove (11) and the rotating tub (211) ;
A reflux element mounted on the nut (2) for circulating and refluxing the plurality of rolling elements (X) ;
A sleeve (31A), comprising a guide member (32A), and an outer cover (33A), said sleeve (31A) is fixed to an end of the nut (2), accompanied with the rotation of the nut (2) is performed axial movement, said guide member (32A) accommodating hole for installing into said sleeve (31A) (311A) is opened, and the second through hole (323A to the guide member (32A) ) and a helical portion (321A) provided for the purpose of the second hole (323A) is inserted the screw shaft (1), further, the guide to the inner edge of the second hole (323A) A fixing portion (3231A) for fitting with the groove (12) is installed, a spiral groove (3211A) is formed between the spiral portion (321A) , and the spiral groove (3211A) extends in a spiral shape. Oil exit hole (322A) at the end in the existing direction ) Opened a constitutes a spiral guideway (60) by the said helical groove (3211A) and the accommodation hole of the sleeve (31A) (311A), also the outer cover (33A) said sleeve (31A) A ball screw provided with a lubricating device, characterized in that a third through hole (331A) for inserting the screw shaft (1 ) is opened. An end surface of said outer cover (33A) and said accommodation hole (311A), said guide member installed in the space of the accommodation hole between the outer cover and (33A) and the end face of the accommodation hole (311A) (311A) (32A) a ball screw provided with a lubricating system according to claim 3, wherein that you have adapted to restrain in order to exercise the axial direction together with the nut (2). A nut (2) provided for a screw shaft (1) including a sleeve (31, 31A ) and a guide member (32, 32A) and having an outer edge provided with a spiral rotation groove (11) and a guide groove (12) And having a rotating tub (211) corresponding to the rotating groove (11) at the inner edge of the perforation (21) and accommodated in a load path composed of the rotating groove (11) and the rotating tub (211). The sleeves (31, 31A) are provided at the ends of the nut (2) that moves in the axial direction of the screw shaft (1) while rotating around the screw shaft (1) by the plurality of rolling bodies (X) that are rotated. The sleeve (31, 31A) is fixed, and moves axially as the nut (2) rotates, so that the guide member (32, 32A) is installed on the sleeve (31, 31A). hole of the housing (311,311A) Opened, also the second hole (323,323A) and the helical portion is the guide member (32, 32A) to (321,321A) provided, the second hole (323,323A) is the screw intended to axis (1) is inserted, further, the fixing portion for mating with said guide groove (12) on the inner edge of the second hole (323,323A) to (3231,3231A) installed, the helical portion forming a spiral groove (3211,3211A) between (321,321A), also Deyu hole in the end portion in a direction extending helically in said spiral groove (3211,3211A) ( 322, 322A) , and the spiral groove (3211, 3211A) and the accommodation hole (311, 311A) of the sleeve (31, 31A) constitute a spiral guideway (60). Lubrication Location.

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