JP2009281489A - Ball screw apparatus equipped with cushioning section - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve such problems that is limited to the space between screws and nuts, and conventional precision ball screws use double-nut system or the like which gives cushioning section, but if a piece of equipment relevant to screw nuts is displaced by temperature variations, the screw nuts come out of commission and the screw nuts are continued by filler piece so that screw nuts may be adversely effected in the tilting rotation and the cushioning pressure must be adjusted by the width of spacer. <P>SOLUTION: This invention sets up two screw nuts in the screw shaft to make the outer gear and inner gear mesh together for connection and keeps the space which absorbs misalignment and errors when rotating to serve as the axial and circumferential cushioning section of the screw shaft so that assembly-inherent error adjustment can be achieved and power transmission device which accepts a high-precision request is possible and power transmission device which accepts a high-precision request is possible. This apparatus has no risk of the screw nuts being declining since all the functions are integrally stored in the housing. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

The present invention relates to a ball screw device in which two ball screw nuts are installed on a ball screw shaft (or ball screw rod) and are connected via a buffer mechanism.

Ball screws are used in various automated devices such as automobiles, game machines, industrial robots, etc., but these are used for industrial machine transfer positioning, and in specialized machine tools and semiconductor manufacturing equipment, more accurate positioning Performance is required.

In conventional ball screws, for high-accuracy positioning, it is common to increase the rigidity by applying a preload to the ball screw to reduce the axial displacement of the ball screw and reduce the amount of elastic displacement with respect to the axial load. It is. An example is a double nut (with a spacer between two nuts in parallel to give a preload). (See Patent Document 1)
JP2002-276765

However, the above precision ball screw has the following problems. If the equipment connected to the ball screw nut is displaced due to temperature change, etc., the ball screw nut will not work properly. Since the ball screw nuts are connected by the spacer, the parallel ball screw nuts may have an adverse effect on the tilt rotation. The preload is only adjusted in the axial direction according to the width of the spacer, and the spacer must be between two ball screw nuts. Furthermore, when using this ball screw, the device must be installed after the housing is attached to the ball screw nut located at the rear. Increasing the preload of the bearing increases the rigidity, but on the other hand, depending on the preload application, there are problems such as a decrease in life, an increase in heat generation, and wear and seizure. Therefore, the conventional ball screw mechanism is not suitable for an efficient and ideal slide.

The present invention solves the above-described problems, and is an apparatus that can maintain a long life and high accuracy. The apparatus structure will be described below.

Install the ball screw nut A and the ball screw nut B through the ball screw shaft. The ball screw nut A is connected to the internal gear through the main body. The ball screw nut B is connected to an external gear through a spacer. By engaging and connecting the external gear and the internal gear, the ball screw nut A and the ball screw nut B are connected via the buffer portion. (See Figure 1)

As described above, the rotational movement of the ball screw shaft is changed to the linear movement by the ball screw nut, so that the apparatus can be slid while maintaining high accuracy.

In the device of 0006 (FIG. 1), a gear is used as a buffer element, but the same function can be achieved even if a pin shaft is used. The main body is installed on the ball screw nut A installed on the ball screw shaft, and the spacer is installed on the ball screw nut B. Connect the pin shaft through the body and spacer. Therefore, the ball screw nut A and the ball screw nut B are connected via the buffer portion. (See Figure 3)

In the present invention, a slide bush is installed on the main body of 0008 (FIG. 3), a fixing nut is installed on the spacer, a pin shaft attached to the fixing nut is passed through the slide bush, and the ball screw nut A and the ball screw nut B are buffered. We have also developed a device for connecting through the section. In the future, depending on the use conditions, we plan to install a slide bush on the sliding surface where the main body and the spacer come into contact. (See Figure 4)

In the above-mentioned 0006 to 0009 (FIGS. 1 to 4), the apparatus is slid by rotating the ball screw shaft, but it is also possible to rotate the apparatus and slide the ball screw rod. (Refer to the description and FIGS. 5 and 6 below.)

In the apparatus shown in FIG. 5, the input shaft is attached to the ball screw nut A, the rotational motion of a motor or the like is transmitted to the input shaft, and the ball screw nut B rotates through the ball screw nut A and the buffer portion. Therefore, the ball screw rod whose rotation is restricted slides. By providing a bearing between the input shaft and the support, rotational motion is not transmitted to the support. When the ball screw rod is fixed, the apparatus can be slid by a rotational movement from a motor or the like.

Similarly, the apparatus shown in FIG. 6 is rotated by providing an input shaft and a support, and the ball screw rod is slid. When the ball screw rod is fixed, the apparatus can be slid by a rotational movement from a motor or the like.

In the apparatus of FIG. 0006 (FIG. 1), the internal gear and the external gear are meshed and connected. This gear is finely moved and buffered by maintaining a space (gap) that absorbs deviations and errors during rotational movement. Then, the spacer slides on the main body, and becomes a buffer portion in the axial direction and circumferential direction of the ball screw shaft. Therefore, it is possible to finely adjust the position of the ball nut B to adjust and maintain assembly errors, inherent errors, and machine errors. In other words, it is a device that can smoothly transmit power that can meet high precision requirements. (See Figure 2)

Similarly, in the apparatus of FIG. 3 (FIG. 3), the spacer slides on the main body so that the contact surface between the pin shaft and the spacer serves as a buffer portion in the axial direction and the circumferential direction, and the position of the ball screw nut B is changed during the rotational movement. By making fine adjustments and absorbing and adjusting deviations and errors, it becomes a device that can smoothly transmit power that can meet high accuracy requirements.

In the apparatus of FIG. 0008 (FIG. 3), the pin shaft and the spacer, the main body and the spacer are in contact with each other, and a sliding surface is generated during operation. If used for many years, damage or failure due to wear or the like may occur. Therefore, as shown in the above-mentioned 0009 (FIG. 4), a slide bush is installed between the pin shaft and the main body, and further between the main body and the spacer, thereby minimizing wear and facilitating fine movement. In addition, the apparatus is improved in terms of accuracy.

In the conventional double nut system described in 0003 above, the ball screw nut will malfunction if the equipment connected to the ball screw nut is displaced due to temperature change or the like. Since it is absorbed by the part, it is a device that can maintain a stable slide without being affected by the displacement of the device. In addition, it is necessary to install a device after using a spacer between two ball screw nuts and attaching a housing to the ball screw nut located on the rear side. Adjust with the function in the device. The spacer installed between the ball screw nuts is adjusted in the axial direction, but this apparatus is provided with a buffer portion at a position outside the boss diameter of the ball screw nut, and is adjusted in the axial direction and the circumferential direction. There is no fear that the ball screw nut will tilt.

Since this device is equipped with a shock absorber, it is a device that can respond to screws of all precision from parallel accuracy to high accuracy, so it is a satisfactory device as a precursor that can respond to various requirements according to usage conditions. It has become.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.

FIG. 1 is an overall view of a gear system for a screw shaft according to the present invention. Install 1 through 2 and 3. 2 is connected to 4 through 7. 3 is connected to 5 through 6. By engaging 4 and 5 and connecting them, 2 and 3 are connected via a buffer.

FIG. 2 is a detailed view of the meshing locations 4 and 5. As shown in the figure, the meshed 4 and 5 are finely moved and buffered by maintaining a space (gap) for absorbing displacement and error during the rotational movement. And it becomes a buffer part of an axial direction and a circumferential direction because 6 slides on 7 side. Therefore, it is possible to finely adjust the position of 3 to adjust and maintain assembly error, inherent error, and machine error. In other words, it is a device that can smoothly transmit power that can meet high precision requirements.

FIG. 3 is an overall view of the pin shaft system for the screw shaft of the present invention. In the apparatus shown in FIG. 1, a gear is used as a buffering element. Install 7 in 2 attached to 1 and 6 in 3. Connect 8 through 6 and 7. Therefore, 2 and 3 are connected via the buffer. By sliding 6 through 7, the contact surface between 6 and 8 becomes a buffer in the axial direction and circumferential direction, and the position of 3 is finely adjusted during rotational movement to absorb and adjust deviations and errors. It will be a device that can smoothly transmit power that can meet the demands of.

FIG. 4 is an overall view of a pin system for a screw shaft using a slide bush. In the apparatus of FIG. 3, 6 and 8, 7 and 8 are in contact with each other, and a sliding surface is generated during operation. If used for many years, damage or failure due to wear or the like may occur. Therefore, a device has also been developed in which 10 is installed in 7, 9 is installed in 6, 8 attached to 9 is fixed through 10, and 2 and 3 are connected via a buffer. In the future, 10 will also be installed on the sliding surface where 6 and 7 are in contact with each other depending on the use conditions. By installing 10 between 7-8 and further between 6-7 as in the apparatus of FIG. 4, wear is minimized and it is easy to finely move. In addition, the apparatus is improved in terms of accuracy.

FIG. 5 is an overall view of the gear system for the rod of the present invention. Rotational motion from a motor or the like is transmitted to 12, and 3 rotates through 2 and a buffer portion connected to 12. Therefore, 11 whose rotation is restricted slides. By providing a bearing between 12 and 13, the rotational movement of 13 is not transmitted. If 11 is fixed, the apparatus can be slid.

FIG. 6 is an overall view of a rod pin shaft system using a slide bush. As in FIG. 5, by providing 12 and 13, this apparatus rotates and 11 is slid. If 11 is fixed, the apparatus can be slid.

Overall view of unit (for screw shaft / gear system) 1-A detailed view Overall view of unit (for screw shaft / pin shaft system) Overall view of unit (screw shaft / slide bushing pin shaft system) Overall view of unit (for rod / gear system) Overall view of the unit (for rods, slide bushed pin shaft system)

Explanation of symbols

1. Ball screw shaft Ball screw nut A
3. Ball screw nut B
4). Internal gear 5. External gear 6. Spacer 7. Main body 8. Pin shaft 9. Fixing nut 10. Slide bush 11. Ball screw rod 12. Input shaft 13. support

Claims (6)

This device, which has a connection function that connects each of the two ball screw nuts installed on the ball screw shaft with a buffering function by meshing the gears in the circumferential direction, is connected at a position outside the boss diameter of the ball screw nut. Ball screw mechanism with shock absorber sliding by. This device, which has a buffering function by passing a plurality of pin shafts through the connecting parts connected to the two ball screw nuts installed on the ball screw shaft, is connected at a position outside the boss diameter of the ball screw nut. Ball screw mechanism with shock absorber sliding by. By connecting the connecting part connected to each of the two ball screw nuts installed on the ball screw rod with a buffering function by meshing the gears in the circumferential direction, and connecting this device at a position outside the boss diameter of the ball screw nut, A ball screw mechanism with a shock absorber that slides with a ball screw rod whose rotation is restricted. Two ball screw nuts installed on the ball screw rod are connected to each other with a buffer function by passing a plurality of pins, and this device connected at a position outside the boss diameter of the ball screw nut rotates to rotate. A ball screw mechanism with a buffering part that the ball screw rod that is regulated slides. 4. The ball screw mechanism with a buffering portion according to claim 3, wherein the ball screw rod is fixed, and the device having a buffering function by meshing the gears in the circumferential direction slides. 5. The ball screw mechanism with a buffering part according to claim 4, wherein the apparatus having a buffering function by passing a plurality of pins is fixed by fixing the ball screw rod.

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