Linear guidance to detect an abnormal circulatory condition

Abstract

Linear guide (10), which comprises: a rail (20) provided on a circumferential surface with two opposing outer rolling grooves (22) thereon; a slider (30) having a sliding groove (31), wherein the slider (30) is slidably disposed on the rail (20) through the sliding groove (31), wherein the sliding groove (31) is provided on an inner wall with two opposite inner rolling grooves (32) thereon, wherein the inner rolling grooves (32) on the slider (30) are arranged correspondingly to the outer rolling grooves (22) of the rail (20) such that the inner rolling grooves (32) of the slider (30) and the outer rolling grooves (22) of the rail (20) form two supporting passages (52), wherein the slider (30) further has two mutually opposite non-supporting passages (33), wherein each of the non-supporting passages (33) passes through two opposite end surfaces of the slider (30); two end caps (40) arranged on the two opposite end surfaces of the slider (30) and each provided with two circulating grooves (43), wherein two ends of each of the circulating grooves (43) of each end cap (40) are respectively communicated with one of the supporting passages (52) and one of the non-supporting passages (33) to form two circulating channels (54), and wherein each of the circulating channels (54) is formed by two of the circulating grooves (43), one of the supporting passages (52) and one of the non-supporting passages (33) together; a plurality of balls (50) arranged in the two circulation channels (54); and a plurality of pressure sensors (60) arranged at two ends of each of the non-supporting passages (33), wherein the pressure sensors are arranged where the circulatory grooves are connected to the non-supporting passages.

Description

BACKGROUND OF THE INVENTION 1. Technical field

[0001] The present invention relates to linear guides and, more particularly, to linear guides capable of detecting an abnormal circulatory condition. 2. Description of the state of the art

[0002] The conventional linear guide comprises a rail and a slider or carriage slidably mounted on the rail, wherein the slider is provided with an end cap at each front and rear end, so that the rail, the slider and the two end caps together form a pair of circulation channels for a plurality of balls moving therein.

[0003] To ensure smooth ball movement, various types of sensors have been used in the prior art to detect abnormal circulation. For example, in German Patent No. DE 19713688 B4, the sensor is arranged in the loading passage to detect the moving distance of the slider or bushing. In German Patent No. DE 102016205575 A1, the sensor for detecting preload is arranged at the cantilevered portion of the loading passage. However, since a preload exists between the slider and the rail, the problem of ball jamming on the loading passage is fundamentally unlikely to occur. Therefore, the abnormal circulation state is difficult to detect in real time by the sensor mounted on the loading passage, as mentioned in the two patents mentioned above.DE3725520 A1 discloses a roller shoe provided with a guideway for the rollers and a deformation sensor provided on a body of the roller shoe for measuring the load. The sensor can be a strain gauge, a piezoelectric element, a semiconductor strip, or a magnetostrictive element attached to a non-directly loaded part of the body. JP2008304244 A discloses a testing method for linear guides to check whether each rolling element is inserted into each corresponding receiving hole of a band-shaped rolling element separator. For this purpose, a sliding piece is moved at a constant speed, with a rolling element sensor located on the sliding piece. While the band-shaped rolling element separator traverses a rolling element circulation path in the sliding piece, the number of peaks or the peak interval of a rolling element detection signal output by the rolling element sensor is detected. SUMMARY OF THE INVENTION

[0004] It is a main object of the present invention to provide a linear guide in which it is possible to detect in real time whether the movement of the balls has an irregularity.

[0005] To achieve the above-mentioned main object, the linear guide of the present invention comprises a rail, a slider, two end caps, a plurality of balls, and a plurality of force or load or pressure sensors. The rail has two mutually opposite outer rolling grooves or recesses on the outer surface. The slider has a sliding groove or recess and is slidably arranged on the rail via the sliding groove. The sliding groove has two opposite inner rolling grooves on the inner wall. The inner rolling grooves of the slider correspond respectively to the outer rolling grooves of the rail, so that a load passage or passage is formed between each inner rolling groove and the correspondingly arranged outer rolling groove. In addition, the slider further has two mutually opposite non-load-bearing passages. Each of the non-load-bearing passages passes through two opposite end surfaces of the slider.The two end caps are arranged on two opposite end surfaces of the slider, and each is provided with two circulating grooves or recesses. Two ends of each circulating groove of each of the end caps communicate with one end of the load-bearing passage and one end of one of the non-load-bearing passages, respectively, to form two circulating channels. Each of the circulating channels is formed by two of the circulating grooves, one of the load-bearing passages, and one of the non-load-bearing passages together for the balls moving in the circulating channels. Pressure sensors are arranged paired at two ends of the two non-load-bearing passages to detect the force-bearing state of the two non-load-bearing passages when the two non-load-bearing passages are loaded by balls.

[0006] Since ball jamming occurs relatively frequently at the reversal points of the circulatory channels, the linear guide of the present invention is provided with at least one pressure sensor at each of the two ends of each of the non-load-bearing passages. The force or pressure signals detected by the pressure sensors at the two ends of each of the non-load-bearing passages can effectively detect in real time when an abnormal or irregular circulatory condition occurs.

[0007] On the other hand, each of the pressure sensors can be mounted at different positions according to practical requirements. For example, each of the pressure sensors can be arranged on the outer peripheral surface of a circulating tube inserted into one of the non-supporting passages, wherein one end of the circulating tube communicates with one of the circulating grooves of each of the end caps. Alternatively, each of the pressure sensors can be provided in a depression provided on the inner wall of the non-supporting passages.

[0008] Further applicability of the present invention will become apparent from the detailed description provided below. It should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given for illustrative purposes only, since various variations and modifications within the scope of the invention will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of the appearance of a linear guide of a first embodiment of the present invention. Fig. 2 is a partially exploded view of the linear guide of the first embodiment of the present invention, but does not show a rail thereof. Fig. 3 is a sectional view of the linear guide of the first embodiment of the present invention. Fig. 4 is a partially enlarged view of Fig. 3. Fig. 5 is a partially exploded view of a linear guide of a second embodiment of the present invention, but does not show a rail thereof. Fig. 6 is a partial sectional view of the linear guide of the second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] First, it should be noted that, for the purpose of accurately describing the present invention, like reference numerals used in the following embodiments and the accompanying drawings denote like or similar elements or structural features thereof throughout the description.

[0010] Referring to the Fig. 1 and Fig. 2, the linear guide 10 of the first embodiment of the present invention includes a rail 20, a slider 30, two end caps 40, and a plurality of pressure sensors 60.

[0011] The rail 20 is provided on each of the two opposite sides with two outer rolling grooves 22 which are arranged one above the other.

[0012] The slider 30 has a sliding groove 31 and is arranged on the rail 20 by the sliding groove 31 such that the slider 30 can slide along the rail 20. The sliding groove 31 of the slider 30 is provided on each of the two opposite sides of the inner wall with two inner rolling grooves 32, which are arranged one above the other. The inner rolling grooves 32 of the slider 30 are arranged corresponding to the outer rolling grooves 22 of the rail 20, so that a Fig. 3 is formed between each inner rolling groove 32 and the correspondingly arranged outer rolling groove 22. Furthermore, the slider 30 is provided on each of the two opposite outer sides of the sliding groove 31 with two non-supporting passages 33 arranged one above the other. Each of the non-supporting passages 33 passes through the front and rear end surfaces of the slider 30.

[0013] The two end caps 40 are mounted on the front and rear end surfaces of the slider 30. Since the two end caps 40 are identical, only one of them is explained below. As shown in Fig. As shown in Figure 2, the end cap 40 comprises a base 41, a circulating member 42, and a cover plate 44. The base 41 rests on the end surface of the slider 30. The circulating member 42 is enclosed in the base 41. The inner end surface of the circulating member 42 is provided on each of the two opposite sides with two circulating grooves 43 arranged one above the other. Two ends of each circulating groove 43 are respectively connected to the supporting passage 52 and the non-supporting passage 33, so that the two circulating grooves 43 arranged corresponding to each other and one in front of the other, a supporting passage 52 and a non-supporting passage 33, together form a circulating channel 54 for a plurality of balls 50 moving therein, as shown in Figure 2. Fig. 3 shown, train.

[0014] The cover plate 44 is arranged on the outer end surface of the base 41 so that the cover plate 44 is attached to the slider 30 together with the base 41 by fastening members such as screws (not shown), and the cover plate 44 covers the circuit member 42.

[0015] There are sixteen pressure sensors 60 arranged in pairs. In this embodiment, as shown in the Fig. 2-4, each of the non-bearing passages 33 is provided with a circulating tube 34 inserted therein. Each of the two ends of each circulating tube 34 is connected to one end of a circulating groove 43. Furthermore, each end of each circulating tube 34 is provided on the outer peripheral surface with a pair of pressure sensors 60. In this way, the force-bearing state of the non-bearing passages 33 can be detected in real time by the pressure sensors 60 when the non-bearing passages 33 are loaded by the balls 50.

[0016] Since the problem of ball jamming occurs relatively frequently at the reversal points of the circulation channels 54, i.e., the two ends of the non-load-bearing passages 33, the pressure sensors 60 mounted at the positions described above are relatively more suitable for detecting the abnormally increasing force absorption signals. If the force absorption signals increase abnormally, this indicates that the inner wall is being loaded by the balls 50. The force absorption signals detected by the pressure sensors 60 are then transmitted for analysis to a control module 62 arranged in the base 41, which can be used to determine when a circulation problem occurs.

[0017] In the first embodiment described above, the pressure sensor 60 is arranged indirectly at one end of the non-supporting passage 33 via the circulatory tube 34. According to the second embodiment of the present invention, however, the pressure sensor 60 is arranged directly at one end of the non-supporting passage 33. More specifically, each of the two ends of each non-supporting passage 33, as shown in the Fig.5-6, two opposing containment troughs 35 are provided on the inner wall. A pressure sensor 60 is provided in each of the containment troughs 35. Thus, the pressure sensor 60 can accurately detect the impact force exerted by the balls 50 on the non-bearing passages 33. In summary, in the linear guide 10 of the present invention, the pressure sensors 60 are directly or indirectly disposed at two ends of the non-bearing passages 33 to detect whether the alignment of the balls 50 causes an abnormal impact condition. Compared with the prior art, the present invention can more accurately determine the circulation state, thereby achieving the effect of early detection.

Claims

[1] Linear guide (10), which comprises: a rail (20) provided on a circumferential surface with two opposing outer rolling grooves (22) thereon; a slider (30) having a sliding groove (31), wherein the slider (30) is slidably disposed on the rail (20) through the sliding groove (31), wherein the sliding groove (31) is provided on an inner wall with two opposite inner rolling grooves (32) thereon, wherein the inner rolling grooves (32) on the slider (30) are arranged correspondingly to the outer rolling grooves (22) of the rail (20) such that the inner rolling grooves (32) of the slider (30) and the outer rolling grooves (22) of the rail (20) form two supporting passages (52), wherein the slider (30) further has two mutually opposite non-supporting passages (33), wherein each of the non-supporting passages (33) passes through two opposite end surfaces of the slider (30); two end caps (40) arranged on the two opposite end surfaces of the slider (30) and each provided with two circulating grooves (43), wherein two ends of each of the circulating grooves (43) of each end cap (40) are respectively communicated with one of the supporting passages (52) and one of the non-supporting passages (33) to form two circulating channels (54), and wherein each of the circulating channels (54) is formed by two of the circulating grooves (43), one of the supporting passages (52) and one of the non-supporting passages (33) together; a plurality of balls (50) arranged in the two circulation channels (54); and a plurality of pressure sensors (60) arranged at two ends of each of the non-supporting passages (33), wherein the pressure sensors are arranged where the circulatory grooves are connected to the non-supporting passages. [2] A linear guide (10) according to claim 1, wherein each of the two ends of each of the non-supporting passages (33) is provided on an inner wall with a containment trough (35) thereon; wherein each of the containment troughs (35) is provided with one of the pressure sensors (60) therein. [3] The linear guide (10) according to claim 1, wherein each of the non-supporting passages (33) is provided with a circulating tube (34) therein; wherein each of the two ends of each of the circulating tubes (34) is connected to one of the circulating grooves (43) of one of the end caps (40); wherein each of the two ends of each of the circulating tubes (34) is provided on an outer peripheral surface with one of the pressure sensors (60).

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