CN116104919A

CN116104919A - Linear transmission device

Info

Publication number: CN116104919A
Application number: CN202111324528.0A
Authority: CN
Inventors: 余思纬; 陈志祥; 林孟颖
Original assignee: Hiwin Technologies Corp
Current assignee: Hiwin Technologies Corp
Priority date: 2021-11-10
Filing date: 2021-11-10
Publication date: 2023-05-12

Abstract

The invention provides a linear transmission device, which comprises a screw rod, a moving part, a reflux element, a plurality of balls and a sensor. The moving part is sleeved on the screw rod and forms a load path with the screw rod, the backflow element is arranged on the moving part and provided with a backflow path connected with the load path, and the backflow path and the load path form a circulation path for the balls to run. In addition, the moving member has an internal thread groove having an ineffective tooth area, and one end of the moving member has a receiving groove adjacent to the ineffective tooth area, and the sensor is inserted into the receiving groove of the moving member without affecting the operation of the balls. Therefore, the linear transmission device can solve the problem that the sensor protrudes out of the moving piece, so that the arrangement of the surrounding space and the travel of the moving piece are not influenced.

Description

Linear transmission device

Technical Field

The present invention relates to linear drives, and more particularly to a linear drive that does not affect the surrounding space configuration.

Background

Generally, a sensor is disposed on a moving member (such as a nut or a slider) of a conventional linear driving device (such as a ball screw or a linear slide rail), and the sensor is used to sense the temperature, vibration or torsion of the moving member during operation, so that an operator of the machine can monitor in real time to ensure the accuracy of processing or conveying.

For the arrangement of the sensor, the TW I585342 patent applies the sensor to the nut or slider with a sensing port; the TW I683984 patent locates the sense die within an overhanging portion of the sense housing that extends into a recessed groove recessed from an axial or radial face of the nut; TW I701101 patent sets up the constant head tank in the axial or radial concave of the outer bulge loop of nut, sets up embedded device in the constant head tank, and the sensing module is located the constant head tank and reaches signal connection with embedded device. However, in the above three patent documents, the sensor protrudes out of the nut after the installation, so that the arrangement of the existing mechanism around the sensor is easily affected, and the stroke of the nut is also affected when the sensor protrudes out of the axial end face of the nut.

On the other hand, the japanese patent laid-open publication No. 58-51052 discloses that a temperature sensor is inserted into the nut from an end face of the nut to sense a temperature change of the nut during operation, but the temperature sensor is already inserted into the effective tooth area (i.e., the area through which the balls pass), so that structural rigidity of the nut is damaged, and even the operation of the balls may be affected.

BRIEF SUMMARY OF THE PRESENT DISCLOSURE

The main object of the present invention is to provide a linear actuator in such a way that the arrangement of the sensors does not affect the configuration of the surrounding space and does not affect the operation of the balls.

In order to achieve the above main object, the linear driving device of the present invention comprises a screw, a moving member, a return member, a plurality of balls, and a sensor. The outer surface of the screw is provided with an external thread groove; the moving part is provided with a screw hole, the moving part is sleeved on the screw rod in an axial displacement way by the screw hole, the hole wall of the screw hole is provided with an internal thread groove, the internal thread groove of the moving part and the external thread groove of the screw rod are correspondingly matched with each other to form a load path, the internal thread groove is provided with an invalid tooth zone, one end of the moving part is provided with an accommodating groove, and the accommodating groove is adjacent to the invalid tooth zone of the internal thread groove; the return element is arranged on the moving part and provided with a return path which is connected with the load path and forms a circulation path for the balls to run with the load path; the sensor is arranged in the accommodating groove of the moving part and senses the temperature, vibration or torsion and other values of the moving part in the running process.

Therefore, the linear transmission device of the invention embeds the sensor in the accommodating groove, so that the sensor does not protrude from the moving member, and therefore, the arrangement of the surrounding space and the travel of the moving member are not affected, and even the size of the moving member can be properly reduced to meet different use requirements. In addition, since the receiving groove is connected with the ineffective dental area and is positioned in the non-load area, the sensor does not damage the structural rigidity of the moving part after the assembly is completed and does not influence the operation of the balls.

Preferably, a connecting line between a point of the reflux element farthest from the center of the screw hole and the center of the screw hole is a signal source radius, the center of the screw hole is used as a circle center, a length difference between the signal source radius and the radius of the screw hole is used as a radius to draw a circle to define a ring-shaped signal sensitive area, the sensor is provided with a vibration sensing chip, and the vibration sensing chip is positioned in the signal sensitive area, so that the most accurate signal source can be obtained, and the most accurate monitoring is realized.

Preferably, the sensor has a temperature sensing chip, the temperature sensing chip is abutted against the moving member, and an interposer made of an electrical insulating material or a heat conducting material can be arranged between the temperature sensing chip and the moving member to prevent noise.

Preferably, the moving member may be a nut or a slide, and if the moving member is a nut, the accommodating groove may be formed by axially or radially recessing from an end surface of the nut along the screw hole, or formed by jointly recessing from an end surface of the nut along the axial direction of the screw hole and the outer periphery of the nut along the radial direction of the screw hole; in the case of a sliding seat, the accommodating groove is formed by recessing from one end surface of the sliding seat along the axial direction of the screw hole.

Preferably, the sensor is covered by a cover plate arranged in the accommodating groove, so as to prevent the sensor from being interfered by external foreign matters to influence the sensing precision.

Preferably, the sensor is connected to a signal line, and the signal line may extend out of the nut along the axial direction of the screw hole or the radial direction of the screw hole to be connected to a signal processor, and the signal processor may be further connected to a terminal processor (e.g. a computer).

Preferably, the sensor is adhesively secured to the moving member, such as with epoxy.

The detailed construction, features, assembly or manner of use of the linear actuator provided by the present invention will be described in the detailed description of the embodiments that follow. However, those of ordinary skill in the art will appreciate that the detailed description and the specific embodiments that are described in connection with the practice of the invention are presented for purposes of illustration only and are not intended to limit the scope of the invention as defined by the claims which follow.

Drawings

Fig. 1 is a perspective view of a linear actuator according to embodiment 1 of the present invention.

Fig. 2 is a partially exploded perspective view of the linear actuator of embodiment 1 of the present invention.

Fig. 3 is a cross-sectional view of fig. 1 taken along line 3-3.

Fig. 4 is a cross-sectional view of a moving member provided by the linear actuator of embodiment 1 of the present invention.

Fig. 5 is an end view of the linear actuator of embodiment 1 of the present invention.

Fig. 6 is a block diagram of a linear actuator according to embodiment 1 of the present invention.

Fig. 7 is a perspective view of the linear actuator of embodiment 2 of the present invention with the screw omitted.

Fig. 8 is a partial exploded perspective view of fig. 7.

Fig. 9 is an end view of fig. 7.

Fig. 10 is a perspective view of the linear actuator of embodiment 3 of the present invention with the screw omitted.

Fig. 11 is a partial exploded perspective view of fig. 10.

Fig. 12 is an end view of fig. 10.

Fig. 13 is a perspective view of the linear actuator of embodiment 4 of the present invention with the screw omitted.

Fig. 14 is a partial exploded perspective view of fig. 13.

Fig. 15 is an end view of fig. 13.

Fig. 16 is a perspective view of a linear actuator according to embodiment 5 of the present invention.

Fig. 17 is a partially exploded perspective view of the linear actuator of embodiment 5 of the present invention.

Fig. 18 is an end view of a moving member provided by the linear actuator of embodiment 5 of the present invention.

Description of the reference numerals

10: linear transmission device

20: screw rod

22: external thread groove

30: moving part

31: body

32: flange

33: screw hole

34: internal thread groove

35: ineffective dental area

36: accommodating groove

37: accommodating groove

40: reflow element

42: reflux path

50: ball bearing

52: load path

54: circulation path

60: sensor device

61: temperature sensing chip

62: vibration sensing chip

63: cover plate

M: signal sensitive area

R: radius of signal source

r: radius of screw hole

64: signal line

65: signal processor

66: terminal processor

67: cover plate

70: reflow element

72: reflow element

80: moving part

81: screw hole

82: accommodating groove

83: cover plate

84: reflow element

Detailed Description

Applicant hereby gives notice that throughout this specification, including the examples presented below and the claims appended hereto, directional terms are used to refer to the directions in the drawings. Next, in the embodiments to be described below and the drawings, the same element numerals denote the same or similar elements or structural features thereof.

Referring to fig. 1 to 3, a linear driving device 10 according to embodiment 1 of the present invention includes a screw 20, a moving member 30, two return members 40, a plurality of balls 50, and a sensor 60.

The outer surface of the screw 20 has an external thread groove 22 extending in the axial direction thereof.

The moving member 30 is a nut in this embodiment and has a body 31, a flange 32 connected to one end of the body 31, and a screw hole 33 penetrating the body 31 and the flange 32. The moving member 30 is sleeved on the screw 20 through a screw hole 33 and can move along the axial direction of the screw 20, the hole wall of the screw hole 33 is provided with an internal thread groove 34, and the internal thread groove 34 of the moving member 30 and the external thread groove 22 of the screw 20 are correspondingly matched with each other to form a load path 52 (shown in fig. 4). In addition, as shown in fig. 3, the internal thread groove 34 has an ineffective tooth area 35 (i.e. an area through which the ball 50 does not pass), and the moving member 30 in this embodiment has a receiving groove 36 recessed from an end surface of the flange 32 facing away from the body 31 along the axial direction of the screw hole 33, and the receiving groove 36 is adjacent to the ineffective tooth area 35 of the internal thread groove 34. It should be noted that the present invention is also applicable to the specifications of small nuts, in which the moving member 30 (nut) has no flange structure, and the receiving groove 36 is formed by axially or radially recessing from an end surface of the nut along the screw hole 33.

As shown in fig. 4, two reflow elements 40 are assembled at two ends of the moving member 30, and the two reflow elements 40 respectively have one reflow path 42, and the two reflow paths 42 respectively connect two ends of the load path 52, so that the two reflow paths 42 and the load path 52 together form a circulation path 54 for the balls 50 to travel.

The sensor 60 is disposed in the receiving groove 36 of the moving member 30 and is fixed to the moving member 30 using an adhesive (e.g., epoxy) that is electrically insulated from the moving member. The sensor 60 is covered by a cover 63 disposed in the accommodating groove 36, so as to prevent the sensor 60 from being interfered by external foreign matters (such as dust) to affect the sensing accuracy. As shown in fig. 2 and 5, the sensor 60 has a temperature sensing chip 61, the temperature sensing chip 61 is abutted against the moving member 30 to sense the temperature variation of the moving member 30 during operation, and an interposer (not shown) made of an electrically insulating material or a heat conducting material may be further disposed at a contact position between the temperature sensing chip 61 and the moving member 30 to prevent noise. As shown in fig. 2 and 5, the sensor 60 further has a vibration sensing chip 62, the vibration sensing chip 62 is located in a ring-shaped signal sensing area M for sensing vibration of the moving member 30 during operation, the signal sensing area M is defined by a circle drawn by taking a center C of the screw hole 33 as a center and a length difference between a radius R of the signal source and a radius R of the screw hole 33 as a radius, wherein the radius R of the signal source is a connection line between a point of the return element 40 farthest from the center C of the screw hole 33 and the center C of the screw hole 33, and the configuration can obtain the most accurate sensing result. As shown in fig. 1, 2 and 6, the sensor 60 is connected to a signal line 64, and the signal line 64 penetrates out of the moving member 30 along the axial direction of the screw hole 33 in the present embodiment to be connected to a signal processor 65, and the signal processor 65 is further connected to a terminal processor 66 (e.g. a computer) for analyzing and subsequently monitoring the sensing result of the sensor 60.

On the other hand, the structure of the present invention may be variously changed. Referring to fig. 7 and 8, embodiment 2 of the present invention is similar to embodiment 1 in structure, in that the receiving groove 36 is formed by recessing from an end surface of the flange 32 opposite to the main body 31 along the axial direction of the screw hole 33 and along the radial direction of the screw hole 33 from the outer periphery of the flange 32, the sensor 60 is disposed in the receiving groove 36 and covered by the cover 67, and the size of the cover 67 needs to be matched with the size of the receiving groove 36, so that the cover 67 can fix the sensor 60 in the receiving groove 36. It should be noted that the present invention is also applicable to the specifications of small nuts, in which the moving member 30 (nut) has no flange structure, and the receiving groove 36 is formed by jointly recessing from one end surface of the nut along the axial direction of the screw hole 33 and from the outer periphery of the nut along the radial direction of the screw hole 33. In addition, the signal line 64 connected to the sensor 60 is connected to the signal processor 65 along the radial direction of the screw hole 33 and extends out of the moving member 30. As shown in fig. 9, in embodiment 2 of the present invention, the temperature sensor chip 61 of the sensor 60 is also attached to the moving member 30 for sensing the temperature change of the moving member 30 during operation, and the vibration sensor chip 62 of the sensor 60 is also located in the annular signal sensitive area M for precisely sensing the vibration condition of the moving member 30 during operation.

Referring to fig. 10 and 11, embodiment 3 of the present invention is similar to embodiment 2 in structure, and the main difference is that the number of the reflow elements 70 provided in embodiment 3 of the present invention is four, and the four reflow elements 70 are embedded in the body 31 of the moving member 30 and are spirally arranged along the axial direction of the screw hole 33, so that the balls 50 form an inner circulation type operation. As shown in fig. 12, in embodiment 3 of the present invention, the vibration sensor chip 62 of the sensor 60 is also located in the annular signal sensitive area M for accurately sensing the vibration condition of the moving member 30 during operation.

Referring to fig. 13 and 14, embodiment 4 of the present invention is similar to embodiment 3 in structure, and the main difference is that the return element 72 provided in embodiment 4 of the present invention is bent and only one in number, and the return element 72 passes out of the body 31 of the moving member 30, so that the balls 50 form an external circulation type operation. As shown in fig. 15, in embodiment 4 of the present invention, the vibration sensor chip 62 of the sensor 60 is also located in the annular signal sensitive area M for accurately sensing the vibration condition of the moving member 30 during operation.

Referring to fig. 16 and 17, the moving member 80 according to embodiment 5 of the present invention is different from the moving member 30 according to each of the above embodiments. In embodiment 5 of the present invention, the moving member 80 is a sliding seat with a screw hole 81, the accommodating groove 82 is recessed from one end surface of the sliding seat along the axial direction of the screw hole 81, two end surfaces of the moving member 80 are respectively provided with a cover plate 83, wherein one cover plate 83 covers the accommodating groove 82, so that the sensor 60 is kept in the accommodating groove 82, and the number of the backflow elements 84 is one and is disposed on the bottom surface of the moving member 80. As shown in fig. 17, the signal line 64 connected to the sensor 60 is connected to the signal processor 65 by penetrating the moving member 80 upward along the radial direction of the screw hole 81. As shown in fig. 18, in embodiment 5 of the present invention, the temperature sensor chip 61 of the sensor 60 is also abutted against the moving member 80 for sensing the temperature change of the moving member 80 during operation, and the vibration sensor chip 62 of the sensor 60 is also located in the annular signal sensitive area M for precisely sensing the vibration condition of the moving member 80 during operation.

In summary, the sensor 60 is embedded in the accommodating groove 36, so that the sensor 60 does not protrude from the moving member 30, and therefore, the arrangement of the surrounding space and the travel of the moving member 30 are not affected, and even the size of the moving member 30 can be properly reduced to meet different usage requirements, and the sensor 60 can be applied to different kinds of moving members 30 (nuts) or moving members 80 (sliders). In addition, since the receiving groove 36 is connected to the inactive dental region 35 to be located in an unloaded area, the operation of the balls 50 is not affected after the sensor 60 is assembled, and the moving

members

30, 80 can be maintained with good structural rigidity.

Claims

1. A linear drive comprising:

the outer surface of the screw is provided with an external thread groove;

the moving part is provided with a screw hole, the moving part is sleeved on the screw rod in an axial displacement way by the screw hole, the hole wall of the screw hole is provided with an internal thread groove, the internal thread groove of the moving part and the external thread groove of the screw rod are correspondingly matched with each other to form a load path, the internal thread groove is provided with an invalid tooth zone, one end of the moving part is provided with a containing groove, and the containing groove is adjacent to the invalid tooth zone of the internal thread groove;

the reflow element is arranged on the moving piece and provided with a reflow path, and the reflow path is connected with the load path and forms a circulation path with the load path;

a plurality of balls provided in the circulation path; and

and the sensor is arranged in the accommodating groove of the moving part.

2. The linear actuator of claim 1, wherein the sensor has a vibration sensor chip located in a ring-shaped signal sensitive area, the signal sensitive area being defined by a circle drawn by a length difference between a radius of a signal source and a radius of the screw hole as a radius, wherein the radius of the signal source is a line between a point of the return element furthest from the center of the screw hole and the center of the screw hole.

3. The linear actuator of claim 1, wherein the sensor has a temperature sensor chip, and the temperature sensor chip is abutted against the moving member.

4. The linear actuator of claim 1, wherein the moving member is a nut, and the receiving groove is formed by axially or radially recessing an end surface of the nut along the screw hole.

5. The linear actuator of claim 1, wherein the moving member is a nut, and the receiving groove is formed by recessing from an end surface of the nut along an axial direction of the screw hole and from an outer periphery of the nut along a radial direction of the screw hole.

6. The linear actuator of claim 1, wherein the moving member is a slide, and the receiving slot is recessed from an end surface of the slide along an axial direction of the screw hole.

7. The linear actuator of claim 1, further comprising a cover plate disposed in the receiving slot and covering the sensor.

8. The linear actuator of claim 1, wherein the sensor is connected to a signal wire that extends out of the nut along an axis of the threaded bore.

9. The linear actuator of claim 1, wherein the sensor is connected to a signal wire that extends radially out of the nut along the screw hole.

10. The linear actuator of claim 1, wherein the sensor is adhesively secured to the moving member.