TWI513927B - Ball screw for immediate monitoring of parallelism - Google Patents

Description

Ball screw for immediate monitoring of parallelism

The invention relates to a ball screw, and more particularly to a ball screw for immediate monitoring of parallelism.

The ball screw is a commonly used component in precision positioning. The ball is used as a power transmission interface between the screw and the nut in a rolling manner to greatly reduce the frictional resistance of the nut when it is actuated. However, when the ball screw is assembled on the machine table, it is usually necessary to correct the parallelism of the screw through the relevant assembly experience. If the relevant personnel do not have enough assembly experience, it is easy to cause the parallelism of the screw to be biased. After a long period of operation, it will affect the service life of the ball screw.

The Republic of China Patent Publication No. TW 201204960 discloses a "balloon lead screw pre-pressure failure diagnosis method and device" which performs empirical mode decomposition filtering on the voiceprint signal emitted by the ball screw when rotating, and then uses the Hilbert The special yellow transform (HHT) to generate the Hilbert yellow map (HHS), followed by multi-scale entropy extraction to generate the multi-scale entropy complexity pattern of the voiceprint signal, and finally the original multi-scale entropy complexity mode With the multi-scale entropy complexity mode of the current situation, it can effectively diagnose whether the pre-pressure of the ball screw disappears, and provide the user with monitoring of the ball screw. However, the aforementioned patents have no way to directly measure the parallelism of the screw after assembly, but can only be indirectly measured by the measured pre-pressure. Therefore, the aforementioned patent does not provide the parallelism of the screw. Accurate measurement knot fruit.

The main object of the present invention is to provide a ball screw for real-time monitoring of parallelism, which can directly sense the parallelism of the screw, is less susceptible to external interference during the sensing process, and thus affects the accuracy, and thus can be instantly used by the user. Monitor the status of parallelism.

In order to achieve the foregoing object, the ball screw of the present invention comprises a screw, a second nut, a joint key, a plurality of balls, and a two parallelism sensor. The screw has an external thread; each of the nut is sleeved on the screw, and the inner ring of each nut has an inner circulation passage and an internal thread, and the internal thread of each nut is between the external thread of the screw Forming a spiral path, the spiral path is connected to the inner circulation passage of each nut, and each of the outer ring of the nut has a key groove; the connecting key is disposed in the key groove of the two nut for The two nuts are coupled together; the balls are rollably disposed in the spiral path and each of the inner circulation passages to reduce frictional resistance of each of the nuts when the screw is actuated; the two parallelism sensors are The screw is centered and oppositely disposed between the opposite end faces of the two nuts to sense whether the pre-pressure between the two nuts changes after assembly, and further whether the screw is maintained at a good level. Parallelism for immediate monitoring by the user.

10‧‧‧Rolling screw

11‧‧‧ screw

12‧‧‧ external thread

19‧‧‧Spiral path

21‧‧‧ nuts

22‧‧‧ internal thread

24‧‧‧Circular passage

26‧‧‧ keyway

31‧‧‧Links

41‧‧‧ balls

51‧‧‧parallel sensor

512‧‧‧Connection block

Fig. 1 is a perspective view showing the combination of the first embodiment of the present invention.

Fig. 2 is an exploded view of the first embodiment of the present invention.

Figure 3 is a plan view of the parallelism sensor of the present invention.

Figure 4 is an end view of the invention.

Fig. 5 is a cross-sectional view taken along line 4-4 of Fig. 3.

Figure 6 is an exploded view of a second embodiment of the present invention.

Referring to FIGS. 1 and 2, the ball screw 10 of the first embodiment of the present invention includes a screw 11, a second nut 21, a joint key 31, a plurality of balls 41, and a four parallelism sensor 51.

The outer peripheral surface of the screw 11 has an external thread 12.

The nut 21 is sleeved on the screw 11, and the inner ring of each nut 21 has an internal thread 22 and an inner circulation passage 24. A screw is formed between the internal thread 22 of each nut 21 and the external thread 12 of the screw 11. Path 19, as shown in Figures 4 and 5, the helical path 19 engages the inner circulation passage 24 of each nut 21. In addition, the outer ring of each nut 21 has a keyway 26, and the two key grooves 26 are opposite to each other and are coupled together.

The connecting key 31 is disposed in the key groove 26 of the two nuts 21 for connecting the two nuts 21 together.

The balls 41 are rollably disposed in the spiral path 19 and the inner circulation passages 24 to reduce the frictional resistance of the two nuts 21 when the screw 11 is actuated.

The parallelism sensor 51 can be any shape when implemented, but in the embodiment, the arc shape is the best choice, and the adjacent two parallelness sensors 51 are connected by the two connection blocks 512 (actually As long as at least one of them can be connected together, as shown in Figure 3. When assembled, the parallelism sensors 51 surround the screw 21 around the screw 21, and two or two Oppositely disposed between the opposite end faces of the two nuts 21, the parallelism sensors 51 can be pressed by the two nuts 31 to sense the pre-pressure between the two nuts 21, after the assembly is completed, The outer arc surface of each parallelity sensor 51 is flush with the outer annular surface of each nut 21. It should be noted that the structural aspect of the parallelism sensor 51 is merely illustrative, and is not intended to limit the scope of the patent, if the parallelism sensor 51 is non-arc shape, or the parallelism sensor When the outer surface of the outer surface of the nut 21 is not flush with the outer surface of the nut 21, it is also a variation of the scope of the patent.

The structure of this embodiment has been described above, and the mode of operation of this embodiment will be described next.

As shown in FIG. 5, when the assembly is completed, the parallelism sensors 51 simultaneously sense the pre-pressure between the two nuts 21, if the pre-pressure sensed by each parallelity sensor 51 is exactly the same. That is, the screw 21 has good parallelism after assembly is completed, and if there is one or more parallelism sensors 51, the sensing result of the pre-pressure between the two nuts 21 is compared with other parallelism. When the sensors 51 are significantly different, that is, the parallelism of the screw 11 after the assembly is completed is deviated, and the position of the screw 11 must be re-corrected.

On the other hand, in actual operation, the two nuts 21 are synchronously displaced along the axial direction of the screw 11 due to the rotation of the screw 11, and the pre-pressure between the two nuts 21 changes during the displacement. At this time, the parallelism sensors 51 are deformed due to the change of the pre-pressure, and further output the corresponding voltage value according to the magnitude of the deformation amount, and the output voltage value can be converted into the operation time. Whether the pre-pressure is normal to ensure that the two nuts 21 are displaced Maintain a good bond in the process.

Referring to FIG. 6 again, the number of the parallelism sensors 51 may vary according to actual needs, and it is not necessary to provide four between the two nuts 21 as in the above embodiment, as long as the two nuts 21 are At least two parallelism sensors 51 are disposed between the opposite end faces, and the two parallelism sensors 51 are opposed to each other with the screw 11 as the center, so that the parallelism of the screw 21 can be sensed as well.

In summary, the ball screw 10 of the present invention monitors the voltage value output by each parallelity sensor 51, in addition to the instantaneous monitoring of the parallelism of the screw 11 during assembly, while in operation It is also ensured that the normal pre-pressure is maintained between the two nuts 21, so that the overall structure has good rigidity, positioning accuracy and positioning stability, and the position of the parallelity sensors 51 is not easily affected by external interference and can be effective. The accuracy of the sensing is improved to achieve the object of the present invention.

10‧‧‧Rolling screw

11‧‧‧ screw

12‧‧‧ external thread

21‧‧‧ nuts

26‧‧‧ keyway

31‧‧‧Links

41‧‧‧ balls

51‧‧‧parallel sensor

Claims (4)

A ball screw for monitoring the parallelism in real time, comprising: a screw having an external thread; and a second nut, the screw is disposed, and the inner ring surface of the two nuts respectively has an inner circulation passage and an internal thread. A spiral path is formed between the internal thread of the two nut and the external thread of the screw, the spiral path is connected to the inner circulation passage of the two nut, and the outer surfaces of the two nuts respectively have a key groove, and the two key grooves respectively Cooperating with each other; a connecting key is disposed in the key groove of the two nuts; a plurality of balls are rollably disposed in the spiral path and each of the inner circulation channels; and at least two parallelism sensors are used The screw is centered and relatively fixed between the opposite end faces of the two nuts. The ball screw for immediate monitoring of parallelism as recited in claim 1, wherein the two parallelism sensors are arcuate. The ball screw capable of monitoring the parallelism in real time according to claim 1, wherein the number of the parallelity sensors is four, and each of the parallelism sensors is arcuate, and the parallelism sensors are The screw is centered around the screw, and two adjacent parallel sensors are physically connected together by at least one connecting block. The ball screw of claim 2 or 3, wherein the parallel arc of the parallelity sensor is substantially flush with the outer annular surface of each of the nuts.