TWI725784B - Self-lubricating ball screw - Google Patents

Abstract

The present invention relates to a self-lubricating ball screw, which includes a screw shaft, a nut displaceably arranged on the screw shaft, a plurality of balls arranged between the screw shaft and the nut, and a screw nut arranged at one end of the nut The lubrication device, which has an oil-containing element and an oil-guiding element. The oil-guiding element contacts the oil-containing element and the screw shaft at the same time to conduct the lubricating oil provided by the oil-containing element to the surface of the screw shaft. In addition, the oil-guiding element At least one pressure sensor is arranged in the vicinity of the element. When the pressure sensor is squeezed by the oil guiding element, a corresponding sensing signal will be generated. With this sensing signal, the operator can determine the oil guiding element in real time Whether there is any abnormal situation of valgus falling off.

Description

Self-lubricating ball screw

The present invention relates to a self-lubricating ball screw, in particular to a self-lubricating ball screw that can instantly sense whether there is an abnormality in the oil guiding element.

The ball screw disclosed in the Republic of China Announcement No. I359237 patent mainly connects two wires to the nut. These two wires form a conductive loop, and the two wires generate a contact resistance through the nut, rolling element and screw. When the oil film attached to the surface of the rolling element disappears, the conductive circuit forms a path to activate a warning device to remind the operator that the lubricant needs to be filled or replaced, thereby ensuring the continuous supply and quality of the lubricant.

However, the aforementioned patent documents use the resistance to form a path to determine the condition of the oil film, and it is impossible to know whether the internal self-lubricating module is abnormal. If the self-lubricating module continues to operate under abnormal conditions, it may cause self-lubrication. Some parts of the moisturizing module (such as wool felt) fall off or are damaged, causing inconvenience in use and trouble in maintenance.

The main purpose of the present invention is to provide a self-lubricating ball screw, which can sense whether the oil guiding element is abnormal.

In order to achieve the above main purpose, the self-lubricating ball screw of the present invention includes a screw shaft, a nut, a plurality of balls, a lubricating device, and a pressure sensor. The nut is sleeved on the screw shaft and can be displaced along the axial direction of the screw shaft; the balls are arranged between the screw shaft and the nut to provide a transmission effect; the lubricating device has a fixed seat, An oil-containing element and an oil-conducting element, the fixing seat is arranged at one end of the nut, the oil-containing element is arranged in the fixing seat to provide lubricating oil, and the oil-containing element is arranged in the fixing seat and contacts the oil-containing element The element and the screw shaft are used for conducting the lubricating oil provided by the oil-containing element to the surface of the screw shaft; the pressure sensor is arranged in the fixing seat and is in contact with the oil guiding element.

From the above, it can be seen that when the pressure sensor is squeezed by the oil guiding element, a sensing signal is generated correspondingly. Using this sensing signal, the operator can instantly determine whether the oil guiding element is overturned, fallen off, or not. Abnormal conditions such as deformation.

Preferably, the fixing seat has a first housing and a second housing, the first housing is arranged at one end of the nut and has a first through hole penetrated by the screw shaft and a surrounding the The first perforated ring groove, the ring groove is provided with the oil-containing element and is enclosed by the oil guide element, and the second shell is provided in the first shell and has a second hole pierced by the screw shaft Perforated, the pressure sensor is arranged on the second housing and adjacent to the second perforated.

Preferably, the second housing has an accommodating groove adjacent to the second through hole, and the pressure sensor is arranged in the accommodating groove to improve the convenience of installation.

Preferably, the second housing has a protruding post adjacent to the second through hole, and the pressure sensor is provided on the protruding post to improve the sensing sensitivity.

Preferably, the pressure sensor has a sensing end, and the outer contour of the sensing end is tangent to the second perforation of the second housing, so that the pressure sensor can perform sensing more efficiently.

Preferably, the number of the pressure sensors can be one or more. If there are more than one, the pressure sensors are arranged at equal angular intervals with the axis of the screw shaft as the center. Have a more comprehensive grasp of whether the oil guiding element is abnormal.

The detailed structure, characteristics, assembly or use of the self-lubricating ball screw provided by the present invention will be described in the detailed description of the subsequent embodiments. However, those with ordinary knowledge in the field of the present invention should be able to understand that the detailed description and the specific embodiments listed for implementing the present invention are only used to illustrate the present invention, and are not intended to limit the scope of the patent application of the present invention.

The applicant first explains here that throughout the specification, including the embodiments described below and the claims in the scope of the patent application, the nouns related to directionality are based on the directions in the drawings. Secondly, in the following embodiments and drawings, the same element numbers represent the same or similar elements or their structural features.

1 to 3, the self-lubricating ball screw 10 of the present invention includes a screw shaft 20, a nut 30, a plurality of balls 40 (the number is not limited), a lubricating device 50, and four pressure sensors器60.

It should be noted that the number of pressure sensors 60 can achieve the effect of pressure sensing as long as there is more than one pressure sensor 60, and the number is not limited. However, the more pressure sensors 60 are provided, the chance of sensing pressure signals will increase.

The nut 30 is sleeved on the screw shaft 20. The balls 40 are arranged between the screw shaft 20 and the nut 30, and the two return elements 42 are combined with the nut 30 to achieve an infinite loop action effect, so that the nut 30 can follow the axis of the screw shaft 20 through the balls 40 Move linearly towards.

The lubricating device 50 has a fixing seat 51, an oil-containing element 54 and an oil guiding element 55.

Please refer to FIG. 3, the fixing base 51 has a first housing 52 and a second housing 53, the first housing 52 is assembled on one end of the nut 30 and has a first sleeve sleeved on the screw shaft 20 The through hole 522 and a ring groove 524 surrounding the first through hole 522. The second housing 53 covers the first housing 52 and has a second through hole 532 and four accommodating slots 534 adjacent to the second through hole 532. The second housing 53 is sleeved on the screw through the second through hole 532轴20.

Please refer to FIG. 4, the four accommodating grooves 534 are arranged at equal angular intervals relative to the second through hole 532. However, in fact, the number of accommodating grooves 534 does not have to be four, as long as the number of pressure sensors 60 It can be matched with each other.

The oil-containing element 54 is made of a polymer material. The oil-containing element 54 has a ring shape and is disposed in the ring groove 524 of the first housing 52, as shown in FIGS. 3 and 5, to provide lubricating oil.

The oil guiding element 55 is made of a material (such as wool felt) that can absorb lubricating oil. The oil guiding element 55 is ring-shaped and has a first side surface 552, a second side surface 554, and an inner ring surface 556. The second side surface 554 faces away from the first side surface 552. The inner ring surface 556 connects the first side surface 552 and the second side surface 552. Side 554.

Please refer to FIG. 5, the oil guiding element 55 contacts the oil containing element 54 with the first side surface 552 and seals the ring groove 524 of the first housing 52. In addition, the oil guiding element 55 is sleeved on the screw shaft 20 and inside The ring surface 556 contacts the outer surface of the screw shaft 20 to conduct the lubricating oil provided by the oil-containing element 54 to the outer surface of the screw shaft 20 so that the screw shaft 20 obtains a lubricating effect.

The pressure sensor 60 can be a force sensitive resistor, a strain gauge, or a load gauge, which is not limited herein. The four pressure sensors 60 are arranged in the four accommodating grooves 534 of the second housing 53 in a one-to-one manner. As shown in FIG. 4, the four pressure sensors 60 are opposite to the second housing 53. The second through holes 532 (that is, relative to the axis of the screw shaft 20) are arranged at equal angular intervals and contact the second side surface 554 of the oil guiding element 55 to sense the force exerted by the oil guiding element 55.

It is worth mentioning that, in this embodiment, each pressure sensor 60 has a sensing end 61, and the outer contour of the sensing end 61 is circular and tangent to the second perforation 532 of the second housing 53. If the oil guide element 55 starts to deform following the action of the screw shaft 20, this position can allow the pressure sensors 60 to perform sensing in the most efficient manner.

It can be seen from the above that when at least one of the pressure sensors 60 is squeezed by the oil guiding element 55, a sensing signal is generated correspondingly, and then this sensing signal is transmitted to a controller (in the figure (Not shown), the controller converts the received sensing signal into a corresponding voltage value. If the voltage value is greater, it means that the force applied by the oil guide element 55 to the pressure sensor 60 is greater, which means The greater the amount of deformation of the oil guide element 55 is.

Please refer to FIG. 7, which shows the changing process of the sensing signal of the pressure sensor 60 being converted into a voltage value when the operator squeezes the oil guide element 55 with different forces, which is used to simulate the actual operation of the oil guide element in this embodiment. For the deformation of 55, at the beginning of the test, the operator first squeezes the oil guide element 55 to a state of large deformation and then captures the voltage value, then pushes the oil guide element 55 back to the original position, and then squeezes the oil guide element 55 Element 55, and repeat the above actions until the oil guiding element 55 is pulled out of the fixing seat 51 to simulate the situation where the oil guiding element 55 is completely released.

It should be noted that in this embodiment, it is preset to be in the safe interval S1 when the voltage value is between 0.5 and 1.5V, and the oil guide element 55 is in the normally assembled and pressed state, and when the voltage value rises to 1.5 to 2.5V, it is in the safe interval S1. In warning zone S2, the oil guiding element 55 has been slightly deformed. At this time, it can be warned by lights or sending a message. When the voltage value rises to 2.5~3.3V, it is in the dangerous zone S3, indicating that the oil guiding element 55 is about to come out However, severe deformation occurs. Once the oil guiding element 55 is completely released, the voltage value will return to zero because the pressure sensor 60 cannot sense the pressure from the oil guiding element 55. In addition, in this embodiment, the voltage value ranges of the safety zone S1, the warning zone S2, and the dangerous zone S3 respectively account for approximately one-third of the distance between the high voltage value (3.3V) and the low voltage value (0.5V), but not With this limitation, the preset voltage value interval can be adjusted according to the actual use state, the specifications of each component, or the type of the pressure sensor 60. In other words, the self-lubricating ball screw 10 of the present invention utilizes the configuration of one or more pressure sensors 60 to allow the operator to instantly determine whether the oil guiding element 55 has an abnormal condition such as eversion, falling off, or deformation, so as to facilitate the self-lubricating of the present invention. The lubricating ball screw 10 can operate smoothly.

It should also be noted that in this embodiment, the four containing grooves 534 are provided in the second housing 53 to facilitate the installation of the pressure sensor 60, and it is also possible to choose not to provide the containing groove 534 to allow the pressure sensor 60 to be installed. It is directly installed in the second housing 53, as long as the pressure sensor 60 contacts the second side surface 554, the effect of detecting pressure can be generated. Even, as shown in FIG. 6, a protrusion 536 is provided on the second housing 53 to improve the sensing sensitivity of the pressure sensor 60, which is also an applicable method.

10: Self-lubricating ball screw 20: screw shaft 30: Nut 40: ball 42: return component 50: Lubrication device 51: fixed seat 52: The first shell 522: first piercing 524: ring groove 53: second shell 532: second perforation 534: Containment Slot 536: Convex Column 54: oil-containing components 55: oil guide element 552: first side 554: second side 556: Inner Ring 60: Pressure sensor 61: sensing end S1: safe zone S2: Warning zone S3: danger zone

Figure 1 is a perspective view of the self-lubricating ball screw of the present invention. Figure 2 is an exploded perspective view of the self-lubricating ball screw of the present invention. Fig. 3 is an exploded perspective view of the lubricating device provided by the self-lubricating ball screw of the present invention. 4 is an end view of the lubricating device provided by the self-lubricating ball screw of the present invention omitting some components. Figure 5 is a partial cross-sectional view of the self-lubricating ball screw of the present invention. Fig. 6 is a partial cross-sectional view of the self-lubricating ball screw of the present invention, which mainly shows that the pressure sensor is installed on the boss. FIG. 7 is a graph showing the relationship between the voltage value and time after the sensing signal of the pressure sensor is converted.

20: screw shaft

30: Nut

52: The first shell

524: ring groove

53: second shell

54: oil-containing components

55: oil guide element

552: first side

554: second side

556: Inner Ring

60: Pressure sensor

Claims (7)

A self-lubricating ball screw includes: a screw shaft; a nut arranged on the screw shaft to be displaced along the axial direction of the screw shaft; and a plurality of balls arranged between the screw shaft and the nut And two return elements are used with the nut to achieve an infinite cycle of actuation effect; a lubricating device has a fixing seat, an oil-containing element and an oil guiding element, the fixing seat is arranged at one end of the nut, and the oil-containing element is provided with In the fixed seat, the oil guide element is arranged in the fixed seat and contacts the oil-containing element and the screw shaft; and at least one pressure sensor is arranged in the fixed seat and contacts the oil guide element so that the The pressure sensor can be squeezed by the oil guiding element to generate a sensing signal. The self-lubricating ball screw according to claim 1, wherein the fixing seat has a first shell and a second shell, and the first shell is arranged on one end of the nut and has a set on the The first perforation of the screw shaft and an annular groove surrounding the first perforation, the second housing is provided in the first housing and has a second perforation set on the screw shaft; the oil-containing element is provided in the first housing In a ring groove of a housing; the oil guide element has a first side surface and a second side surface facing away from the first side surface, and the first side surface of the oil guide element closes the ring groove of the first housing and contacts the Oil-containing element; the pressure sensor is arranged on the second housing and is in contact with the second side surface of the oil guiding element. The self-lubricating ball screw according to claim 2, wherein the second housing has an accommodating groove adjacent to the second perforation, and the pressure sensor is disposed in the accommodating groove. The self-lubricating ball screw according to claim 2, wherein the second housing has a protruding post adjacent to the second through hole, and the pressure sensor is provided on the protruding post. The self-lubricating ball screw according to claim 2, wherein the pressure sensor has a sensing end, and the outer contour of the sensing end is tangent to the second perforation of the second housing. The self-lubricating ball screw according to claim 5 includes a plurality of the pressure sensors, and the pressure sensors are arranged at equal angular intervals relative to the second perforation. The self-lubricating ball screw according to claim 1, wherein the sensing signal of the pressure sensor is transmitted to a controller, and the controller converts the received sensing signal into a corresponding voltage value, When the voltage value is between 0.5~1.5V, it is in a safe zone, when the voltage value is between 1.5~2.5V, it is in a warning zone, and when the voltage value is between 2.5~3.3V, it is in a dangerous zone.

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