JP4303734B2 - Ball screw - Google Patents

Description

The present invention relates to a ball screw having a structure in which a nut is preloaded on a screw by using an offset preload system by providing at least one circulating device.

Conventional ball screw is mostly be used circumfluence tube (return Tube) or circumfluence cap (return cap). By using these conventional circulation devices, the ball screw can set the preload by a method such as a double nut or an offset, and can improve the rigidity of the ball screw. The ball screw with end deflector (end The deflector), (see e.g., Patent Document 1) relatively new design as under the uses end deflector placed at both ends of the nut ball screw in accordance with the times circulation hole for connecting to both end deflectors on the nut (return hole) Te, ball ball groove of the nut in the ball screw, so that can circulate movement between the end deflector and times flow holes There is something configured . However, in a ball screw using such an end deflector, all the balls are moving in the same circulation loop. Therefore, in order to improve the rigidity of the ball screw, the preload is set using the offset method. It is not appropriate to do.

Further, as shown in FIGS. 7 and 7A, a ball screw using an improved end deflector (see, for example, Patent Document 2) has an offset preload system in a single nut 7 as its design. By utilizing this, the ball groove in the ball screw is divided into three regions, the regions on both sides of the ball screw being a load region 7b of the ball, and the intermediate short region is the unloading region 7a of the ball. The groove of the ball groove of the ball no-load region 7a is enlarged, and the ball forms a region with a gap between the ball no-load regions 7a of the ball groove and uses this region with the gap to By changing the groove guideway so that the ball groove guideway is not discontinuous, and the offset value becomes larger or smaller, the balls in the ball load areas 7b on both sides receive an offset preload.

As shown in FIG. 7A, the guide way (lead) of the screw of this system is kept constant, and a guide way having a Q value is offset between the ball load areas 7b on the ball groove of the nut. By setting the preload using an offset preload system, the rigidity of the ball screw can be improved. However, the above-described ball screw offset preload system also has the following three problems. Problem one: It is necessary to divide the ball groove of the nut into three regions, and at the same time, in order to enlarge the groove of the ball groove in the ball no-load region 7a, a stepwise polishing method is used in the ball groove polishing process This is inconvenient for polishing. Problem # 2: The groove of the ball groove in the ball no-load area 7a is enlarged, and the ball in this area is pushed by the gap between the ball and the ball groove, and the balls are pushed and collide with each other. There's a problem. Problem # 3: The nut is long and all balls are in the same circulation loop, and many balls are pushed and connected simultaneously in one ball circulation loop (for example, circulation holes) Therefore, the circulating resistance force is doubled, and the number of balls in the load area 7b of both balls is greatly different.

Since it is impossible to solve the above problems at the same time, it is necessary to improve and improve the conventional ball screw .
US Pat. No. 5,492,036 JP 2002-227756 A

An object of the present invention is to provide a ball screw that can form at least two independent ball circulation loops in a nut having an end deflector and adjust the preload of the nut using an offset preload system. To do . It is another object of the present invention to provide a ball screw that can easily polish a ball groove of a nut and can avoid the problem that the number of pushed balls is reduced and the circulation resistance is doubled in each independent ball circulation loop. . It is another object of the present invention to prevent the number of balls in each ball load area (that is, each ball circulation loop area) from being greatly different.

In order to achieve the above object, the ball screw of the present invention has a nut fitted into the screw, and the ball is located between the screw and the nut so as to move relative to each other. A ball groove matching the groove of the screw is formed on the peripheral surface, a circulation hole is formed in the nut, and the ball groove and the circulation hole are connected to both end surfaces of the nut. In the ball screw provided with an end deflector constituting the ball circulation loop, the nut is formed integrally, and the nut divides the ball circulation loop at the position of the ball groove and the circulation hole. A circulating device is embedded from an outer peripheral surface of the nut, and the circulating device is divided into one side by the circulating device. One circulation channel connecting the circulation hole, and the other circulation channel connecting the ball groove and the circulation hole divided on the other side by the circulation device, the nut, The screw is preloaded by the offset preloading system that makes the distance between the ball circulation loops located on one side and the other side through the circulation device different from the distance between the ball circulation loops determined by the lead of the ball groove. the it is with the features.

  The above-described circulation device having both circulation channels has curved surfaces on both sides thereof, and if the guideway formed with the ball groove in the nut is small, the circulation device is used when the adjacent groove is not perfect due to the processing of the hole groove. It is possible to fill incomplete grooves on the nuts using the curved surfaces on both sides of the circulation device.

  The features and technical contents of the present invention can be better understood by referring to the following description of the embodiments of the present invention or the drawings. However, the implementation method and the drawings are merely used for explanation or reference, and do not limit the present invention.

FIG. 1 is an exploded perspective view of a ball screw according to the present invention. As shown in the figure, the nut 1 of the ball screw is fitted on the screw 2 and relatively moved so that the ball 3 rotates in the meantime. The inner diameter of the nut 1 is provided with a ball groove 1e to be fitted to the screw 2, and the ball 3 can rotate into the circulation channel 4a .

The ball screw of the present invention includes double flow channels 4a assembled in a radial hole groove 1c in the central portion of the nut 1 using at least one flow device 4. After the circulation device 4 is inserted into the radial hole groove 1c, the circulation channel 4a is aligned with the circulation hole 1a of the nut 1, and the screw groove 4b is aligned with the screw groove 1b of the nut 1, and the bolt ( It is possible to conveniently compose the composition by passing between them by a not shown) and fixing the circulating device 4 and the nut 1. Further, each single circumfluence path to both end surfaces of the nut 1 is an end deflector 5 having a (single circumfluence channel) is inserted, combined with two end deflector 5 to the ball groove 1e of circumfluence device 4 and the nut 1 Thus, both independent ball circulation loops are formed, and the ball 3 can move between them.

  As described above, since the balls 3 can move between the two independent ball circulation loops, it is possible to adjust the preload of the nut 1 using an offset preload system.

  2A to 2C are views of the circulating device of the present invention as seen from different angles. FIG. 2A is a front view of the current flow device element, FIG. 2B is a rear view of the current flow device, and FIG. 2C is an exploded perspective view of the current flow device.

These three figures, the outer shape of the circumfluence device 4 of the present invention has a substantially arc shape, circumfluence device 4 smooth kana curved 4c is provided on this smooth kana curved 4c is circumfluence device 4 The outer diameter of the nut 1 is adjusted so as not to protrude from the outer diameter surface of the nut 1. Further, the circulation device 4 includes two circulation channels 4a, and a thread groove 4b is provided on the circulation channel 4a. Circumfluence channel 4a of the is used to communicate the circumfluence hole 1a of the ball groove 1e and the nut 1, the thread groove 4b is used to secure the circumfluence device 4. As a fixing method, first, the circulating device 4 and the radial hole groove 1c of the nut 1 are fitted, and the circulating device 4 is tightened onto the nut 1 along the direction of the thread groove 4b with the nut 6 (see FIG. 3). To do). In this way, the balls 3 smoothly enter the circulation holes 1a of the nut 1 in FIG. 1 and complete the circulation by the guide paths 4d of the both circulation channels 4a of the circulation device 4. In FIG. 2B, the connection region between the two circulation channels 4a and the ball groove 1e is a groove connection port 4e. The design according to the present invention makes the connection ports 4e of both grooves as close as possible and avoids that many areas of the ball groove 1e are not in contact with the ball. Therefore, it is more preferable to set an offset preload. Load capacity is obtained. Further, since the connection ports 4e of both grooves are sufficiently close and the screw paths of both are not clear, they are arranged in a straight line.

  FIG. 4A is a perspective view showing a state in which a nut groove provided in the circulation device of the present invention is filled, and FIG. 4B is a perspective view showing curved surfaces of grooves on both sides of the circulation device of the present invention.

The figure shows a circulation device 4 provided with both of the circulation channels 4a, each having a curved surface ( groove curved surface ) 4e on both sides. When the guide way of the ball groove 1e of the nut 1 is small and the adjacent groove 1e is not perfect due to processing of the circulation device, the curved surface 1e of the incomplete groove of the nut 1 is obtained using the curved surfaces 4e of the grooves on both sides of the circulation device 4. Can be filled.

  FIG. 5 is a perspective view of an embodiment of the present invention. In the offset preload adjustment method, the ball groove 1e of the nut 1 is divided into at least two independent ball circulation loops, and both independent ball circulation loops can have a relative deviation. Since the ball 3 shaded on the right side of the figure and the ball not shaded on the left side belong to the independent ball circulation loops, these two things use the offset preload method, It is possible to improve the rigidity of the nut.

  FIG. 6 is a perspective view of another embodiment of the present invention. When the length of the nut 1 is longer, the purpose is that a large number (three) of ball circulation loops can be formed in the nut 1 by using the double circulation device 4.

In summary, the ball screw of the present invention can be provided in large quantities for industrial use, has high industrial value, has certain novelty, and is disclosed in any public document or exhibition. Therefore, it is fully consistent with the legal and inventive requirements of novelty and inventive step, so a patent application should be submitted by law and allowed by examination.

The exploded perspective view of the ball screw shown as one example of the present invention. The front view of the circulation device in the ball screw . The rear view of the circulation device in the ball screw . The disassembled perspective view of the circulation apparatus in the ball screw . Perspective view showing a state when attaching viewing set the swirling flow device to the nut in the same ball screw. The perspective view which shows the state which filled the nut groove | channel of the circulating device in the ball screw . The perspective view which shows the curved surface of the groove | channel of the both sides of the circulation apparatus in the ball screw . The perspective view which fractured | ruptured and showed the inside of the nut in the same ball screw . It is the ball screw shown as other Examples of this invention , Comprising: The perspective view which fractured | ruptured and showed the inside of the nut . Sectional drawing of the conventional ball screw . Sectional drawing explaining the offset preload in the conventional ball screw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Nut 1a Circulation hole 1b Screw groove 1c Radial hole groove 1e Screw groove 2 Screw 3 Ball 4 Circulation device 4a Circulation channel 4 Screw groove 4c Smooth curved surface 4d Guide path 4e Curved surface 4e Groove connection port 5 End deflector 6 Bolt 7 Single nut 7a Ball load range 7b No-load range of ball

Claims (5)

A nut is fitted on the screw, and the ball is positioned between the screw and the nut so as to rotate relative to each other .
The inner peripheral surface of the nut, the ball grooves fit groove of the screw is formed,
A circulation hole is formed in the nut ,
On both end surfaces of the nut, the ball screw having an end deflector constituting the ball circulation loop by connecting said rotary flow hole with the ball grooves,
The nut is integrally formed,
In the nut, a circulation device that divides the ball circulation loop at the positions of the ball groove and the circulation hole is embedded from the outer peripheral surface of the nut,
The circulation device includes one circulation channel that connects the ball groove divided on one side by the circulation device and the circulation hole, the ball groove divided on the other side by the circulation device, and the circulation. The other circulation channel connecting the flow hole,
The nut is preloaded on the screw by an offset preloading method that makes the distance between the ball circulation loops located on one side and the other side different from the distance between the ball circulation loops determined by the lead of the ball groove via the circulation device. ball screw characterized by Tei Rukoto. Wherein the end deflector is claim 1, wherein the ball screw characterized that you have been buried at each end face of the nut. The circumfluence device, in a state assembled to the nut, according to claim 1, wherein that you have a groove curved for movement of the ball complements the ball grooves which are missing by the Circulating device Ball screw.   The ball screw according to claim 1, wherein a fixing method of the circulating device is tightened on a nut while being along a screw groove direction with a bolt.   2. The ball screw according to claim 1, wherein the connection areas of the both circulation channels and the ball groove are groove connection ports, and the connection ports of the both grooves are linearly arranged with respect to each other.

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