CN223812101U

CN223812101U - Full-closed-loop miniature linear type electric drive joint

Info

Publication number: CN223812101U
Application number: CN202520415698.7U
Authority: CN
Inventors: 严作海; 单作飞
Original assignee: Hangzhou Xinjian Electromechanical Transmission Co ltd
Current assignee: Hangzhou Xinjian Electromechanical Transmission Co ltd
Priority date: 2025-03-10
Filing date: 2025-03-10
Publication date: 2026-01-20
Anticipated expiration: 2035-03-10

Abstract

This utility model relates to the field of mechanical joint technology, specifically to a fully closed-loop miniature linear electric drive joint, comprising a housing, a motor, a ball screw, and a drive unit. Addressing the technical problems of existing linear electric drive joints, this utility model utilizes a planetary ball screw mechanism, significantly improving load-bearing capacity and extending the overall actuator lifespan; it improves the connection method between the motor and the planetary ball screw mechanism, significantly shortening the axial dimension and increasing the power-to-weight ratio; and it achieves high integration of a rotary encoder and a linear displacement sensor with the planetary ball screw mechanism, realizing fully closed-loop control and improving positioning accuracy.

Description

Full-closed-loop miniature linear type electric drive joint

Technical Field

The utility model relates to the technical field of mechanical joints, in particular to a full-closed-loop miniature linear type electric drive joint.

Background

At present, a conventional miniature linear electric drive joint generally adopts a ball screw or a sliding screw, and is basically designed to be that the output of a motor is fixedly connected with the screw, the screw rotates, and a nut moves linearly. However, the ball screw has the defects of small bearing and low output force, while the sliding screw has the defects of large friction force and low efficiency.

And, the integration level of the current miniature linear type electric drive joint is not high, for example, an output end linear type encoder is not integrated with a screw rod, a motor and the screw rod are connected in a spline or other modes, and the like, and the low integration level can limit the upper precision limit, so that the miniature linear type electric drive joint cannot be suitable for a mechanical joint with higher precision.

Disclosure of utility model

Aiming at the technical problems that the existing linear type electric drive joint has defects, the utility model provides a full-closed-loop miniature linear type electric drive joint, which utilizes a planetary roller screw mechanism to greatly improve the bearing capacity and prolong the service life of the whole actuator, improves the connection mode of a motor and the planetary roller screw mechanism, greatly shortens the axial dimension and improves the unit power ratio, and realizes the high integration degree of a rotary encoder, a linear displacement sensor and the planetary roller screw mechanism, thereby realizing the full-closed-loop control and improving the positioning precision.

The technical scheme includes that the full-closed-loop miniature linear electric drive joint comprises a shell portion, a motor portion, a roller screw portion and a driving portion, wherein the roller screw portion is located on the inner side of the shell portion and comprises a screw, rollers and nuts, a plurality of rollers encircle the outer side of the screw and are meshed with the screw, the nuts are located on the outer side of the rollers and are meshed with the rollers, the motor portion comprises a stator and a rotor, the stator is fixed on the inner side of the shell portion, the rotor is located on the inner side of the stator and is fixed on the outer side of the nuts, the driving portion is located in the shell portion, one end of the roller screw portion is sleeved with a sleeve, a magnetic head is arranged on the sleeve, the driving portion comprises a coded disc, the magnetic head and the coded disc form a rotary encoder, a linear displacement sensor is arranged between the screw and the shell portion, one end of the shell portion is fixedly provided with a ball bearing, the ball bearing is integrated with a push-pull force sensor, and the motor portion, the rotary encoder, the linear displacement sensor and the driving portion are all connected.

Optionally, the housing part comprises a first end cover, a main housing, a wiring housing and a second end cover, wherein the first end cover and the wiring housing are respectively fixed at two ends of the main housing, the second end cover is fixed at one end of the wiring housing, which is far away from the main housing, the lead screw penetrates through the first end cover, a first lead hole is formed in the first end cover, a lead of the linear displacement sensor penetrates out of the first lead hole, a second lead hole is formed in the wiring housing, and a lead of the driving part penetrates out of the second lead hole.

Optionally, the screw includes an engagement section and an actuating section, the engagement section is engaged with the roller, the actuating section is fixed to one side of the engagement section, and the linear sensor is located between the actuating section and the housing portion.

Optionally, the length of the engagement section is less than or equal to 1/5 of the length of the execution section.

Optionally, the length of the engagement section is less than or equal to 1/5 of the length of the internal thread of the nut.

Optionally, the linear displacement sensor includes magnetic grating and reading head, the reading head is fixed in on the casing portion, and with drive portion electricity is connected, the magnetic grating is followed the length direction fixed setting of execution section.

Optionally, the length of the magnetic grid is greater than or equal to 85% of the length of the execution segment.

Optionally, a sliding bearing is arranged on the shell part, at least one inner flat position is arranged on the sliding bearing, an outer flat position is correspondingly arranged on the screw rod, and the outer flat position is in butt fit with the corresponding inner flat position.

Optionally, a deep groove ball bearing is provided between the sleeve and the housing portion.

Optionally, a four-point angular contact ball bearing is arranged between one end of the screw rod, which is away from the sleeve, and the housing part.

Advantageous effects

Compared with the prior art, the technical scheme provided by the utility model has the advantages that aiming at the technical problem that the existing linear type electric drive joint has defects, the utility model utilizes the planetary roller screw mechanism, greatly improves the bearing capacity, prolongs the service life of the whole actuator, improves the connection mode of a motor and the planetary roller screw mechanism, greatly shortens the axial dimension, improves the unit power ratio, and realizes the full-closed loop control of a rotary encoder, a linear displacement sensor and the planetary roller screw mechanism and improves the positioning precision.

Drawings

Fig. 1 is a schematic structural diagram of a fully-closed-loop miniature linear electric drive joint according to an embodiment of the present utility model.

Detailed Description

For a further understanding of the present utility model, the present utility model will be described in detail with reference to the drawings and examples.

The utility model is described in further detail below with reference to the drawings and examples. It is to be understood that the specific embodiments described herein are merely illustrative of the utility model and are not limiting of the utility model. It should be noted that, for convenience of description, only the portions related to the utility model are shown in the drawings. The first, second, etc. words are provided for convenience in describing the technical scheme of the present utility model, and have no specific limitation, and are all generic terms, and do not constitute limitation to the technical scheme of the present utility model. It should be noted that, without conflict, the embodiments of the present utility model and features of the embodiments may be combined with each other. In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Unless specifically stated or limited otherwise, the terms "mounted," "connected," "coupled," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, mechanically connected, electrically connected, directly connected, or indirectly connected via an intervening medium, or may be in communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art. The technical schemes in the same embodiment and the technical schemes in different embodiments can be arranged and combined to form a new technical scheme without contradiction or conflict, which is within the scope of the utility model.

Example 1

With reference to fig. 1, this embodiment proposes a full-closed-loop miniature linear electric drive joint, which includes a housing portion, a motor portion, a roller screw portion, and a drive portion.

The roller screw part is positioned on the inner side of the shell part and comprises a screw 10, rollers 11 and a nut 12, wherein a plurality of rollers 11 encircle the outer side of the screw 10 and are meshed with the screw 10, and the nut 12 is positioned on the outer side of the rollers 11 and is meshed with the rollers 11.

The motor part includes a stator 13 and a rotor 14, the stator 13 is fixed inside the housing part, the rotor 14 is located inside the stator 13, and the rotor 14 is fixed outside the nut 12.

The driving part is positioned in the shell part, one end of the roller screw part is sleeved with a sleeve 15, the sleeve 15 is provided with a magnetic head 16, the driving part comprises a code disc 17, the magnetic head 16 and the code disc 17 form a rotary encoder, a linear displacement sensor is arranged between the screw 10 and the shell part, one end of the shell part is fixedly provided with a ball bearing 18, and the ball bearing 18 is integrated with a push-pull force sensor. The motor part, the rotary encoder, the linear displacement sensor and the push-pull force sensor are all electrically connected with the driving part.

Based on the structural characteristics, the working principle of the fully-closed-loop miniature linear electric drive joint in the embodiment is that a planetary roller screw mechanism is composed of a screw rod 10, rollers 11 and a nut 12, threads are machined on the inner side of the nut 12, threads and gears are machined on the rollers 11, and threads and gears are machined on the screw rod 10. The nut 12 is threadedly engaged with the roller 11, and the roller 11 is threadedly engaged with the screw 10 and the gear.

In the motor part, the stator 13 can drive the rotor 14 to drive the nut 12 to rotate, and based on the meshing relationship, the rotation of the nut 12 can drive the screw rod 10 to perform linear motion, and when the motor part is applied to a product such as a manipulator, the linear motion of the screw rod 10 can drive the movement of a finger joint in the manipulator.

The movement of the screw 10 is controlled by a motor section which is controlled by a drive section. In this embodiment, the driving portion is provided in the housing portion at a position near the tip end of the roller screw portion.

The driving part comprises a related hardware circuit and a motor driving and controlling circuit, and further comprises a code disc 17, wherein the tail end of the roller screw part is sleeved with a sleeve 15, namely, the sleeve 15 is fixed on the outer side of the nut 12, the sleeve 15 can rotate along with the rotation of the nut 12, a magnetic head 16 is fixedly arranged on the sleeve 15, and the magnetic head 16 faces the code disc 17, so that the magnetic head 16 rotates along with the rotation of the sleeve 15, the code disc 17 senses the rotation of the magnetic head 16, and the rotary encoder can read rotary electric signals.

And a linear displacement sensor is provided between the screw 10 and the housing portion, and can read the linear displacement of the screw 10. Furthermore, one end of the housing part is fixedly provided with a ball bearing 18 for connection to external mechanisms, such as assembly with components of the manipulator, and which counteracts most non-axial forces. The ball bearing 18 is integrated with a push-pull force sensor, and can collect push-pull force electric signals.

Based on the arrangement of the rotary encoder, the linear displacement sensor and the push-pull force sensor, the driving part can output the motor part by combining the electric signals acquired by the sensors, so that the working condition of the rotor 14 is changed, and the working condition of the screw rod 10 is changed.

In a preferred embodiment, the housing part comprises a first end cap 21, a main housing 23, a terminal housing 24 and a second end cap 22, the first end cap 21 and the terminal housing 24 being fixed to respective ends of the main housing 23, the second end cap 22 being fixed to an end of the terminal housing 24 facing away from the main housing 23. The lead screw 10 penetrates through the first end cover 21, a first lead hole is formed in the first end cover 21, a lead of the linear displacement sensor penetrates out of the first lead hole, a second lead hole is formed in the wiring shell 24, and a lead of the driving part penetrates out of the second lead hole. In this embodiment, the housing portion is formed by combining a plurality of portions with each other, and this combination contributes to improvement in convenience of assembly. And a first lead hole and a second lead hole are reserved so as to facilitate connection of the internal circuit with the outside.

In another preferred embodiment, the screw 10 comprises an engagement section 111 and an actuating section 112, the engagement section 111 being in engagement with the roller 11, the actuating section 112 being fixed to one side of the engagement section 111, the linear position being between the actuating section 112 and the housing part. Thereby, the screw 10 is divided into two parts, the engagement section 111 is for engagement with the roller 11, linear movement occurs with movement of the nut 12, and the execution section 112 mainly serves as a part connected to the outside, and does not participate in engagement. Therefore, only part of the lead screw 10 is used for meshing transmission, only part of the lead screw 10 is used for outputting outwards, the whole service life can be prolonged to a certain extent, and meanwhile, part of processing cost can be reduced.

In a further embodiment, the length of the engaging section 111 is less than or equal to 1/5 of the length of the executing section 112, so that a larger stroke of the executing section 112 can be realized through a smaller engaging area, thereby improving the overall use efficiency.

In another modification similar to the above embodiment, the length of the engagement section 111 is 1/5 or less of the length of the internal thread of the nut 12. The aim is also to reduce the engagement length of the screw 10, so that the actuating section 112 of the screw 10 has a movable stroke as large as possible, and the overall use efficiency is improved.

On the basis of the division of the threaded spindle 10 into the actuating section 112 and the engagement section 111, there is another preferred embodiment in which the linear displacement sensor comprises a magnetic grating 25 and a reading head 26, the reading head 26 being fixed to the housing part and being electrically connected to the drive part, the magnetic grating 25 being fixedly arranged along the length of the actuating section 112. Wherein the read head 26 may be secured to the housing portion near the region through which the implement segment 112 extends. In this embodiment, integration of the linear displacement sensor is further realized, and the arrangement can more accurately read the position signal of the screw 10 in the linear motion process.

In a further embodiment, the length of the magnetic grid 25 is equal to or greater than 85% of the length of the implement section 112. The set length of the magnetic grating 25 is understood to be the effective length of the output of the lead screw 10, and therefore the effective length of the output should be as long as possible, preferably 85% or more of the length of the implement segment 112.

In a preferred embodiment, a sliding bearing 27 is provided on the housing part, at least one inner flat is provided on the sliding bearing 27, an outer flat is provided on the threaded spindle 10, and the outer flat is in contact with the corresponding inner flat. In this embodiment, the screw 10 has one or four or other number of outer flats, and the sliding bearing 27 is provided with corresponding inner flats, which cooperate with the outer flats to realize an anti-rotation function. And the arrangement of the sliding bearing 27 can reduce wear between the screw 10 and the housing part.

And, in order to ensure smoothness and stability of the rotation of the nut 12, a deep groove ball bearing 28 may be provided between the sleeve 15 and the housing portion. Similarly, a four-point angular ball bearing 29 may be provided between the end of the spindle 10 facing away from the sleeve 15 and the housing part, in order to carry axial and radial loads.

In summary, aiming at the technical problem that the existing linear type electric drive joint has defects, the full-closed-loop miniature linear type electric drive joint provided by the embodiment utilizes the planetary roller screw mechanism, so that the bearing capacity can be greatly improved, the service life of the whole actuator is prolonged, the connection mode of a motor and the planetary roller screw mechanism is improved, the axial size is greatly shortened, the unit power ratio is improved, and the rotary encoder, the linear displacement sensor and the planetary roller screw mechanism are highly integrated, so that full-closed-loop control is realized, and the positioning precision is improved.

The utility model and its embodiments have been described above schematically, without limitation, and the actual construction is not limited to this, as it is shown in the drawings, which are only one of the embodiments of the utility model. Therefore, if one of ordinary skill in the art is informed by this disclosure, a structural manner and an embodiment similar to the technical scheme are not creatively devised without departing from the gist of the present utility model, and all the structural manners and the embodiments belong to the protection scope of the present utility model.

Claims

1. The full-closed-loop miniature linear electric drive joint is characterized by comprising a shell part, a motor part, a roller screw part and a drive part;

The roller screw rod part is positioned at the inner side of the shell part and comprises a screw rod (10), rollers (11) and nuts (12), wherein a plurality of rollers (11) encircle the outer side of the screw rod (10) and are meshed with the screw rod (10), and the nuts (12) are positioned at the outer side of the rollers (11) and are meshed with the rollers (11);

The motor part comprises a stator (13) and a rotor (14), the stator (13) is fixed on the inner side of the shell part, the rotor (14) is positioned on the inner side of the stator (13), and the rotor (14) is fixed on the outer side of the nut (12);

The driving part is positioned in the shell part, one end of the roller screw part is sleeved with a sleeve (15), a magnetic head (16) is arranged on the sleeve (15), the driving part comprises a code disc (17), the magnetic head (16) and the code disc (17) form a rotary encoder, a linear displacement sensor is arranged between the screw (10) and the shell part, one end of the shell part is fixedly provided with a ball bearing (18), the ball bearing (18) is integrated with a push-pull force sensor, and the motor part, the rotary encoder, the linear displacement sensor and the push-pull force sensor are all electrically connected with the driving part.

2. The fully-closed miniature linear electric drive joint according to claim 1, characterized in that the housing part comprises a first end cap (21), a main housing (23), a terminal housing (24) and a second end cap (22), the first end cap (21) and the terminal housing (24) being fixed to both ends of the main housing (23), respectively, the second end cap (22) being fixed to an end of the terminal housing (24) facing away from the main housing (23);

The lead screw (10) penetrates through the first end cover (21), a first lead hole is formed in the first end cover (21), a lead of the linear displacement sensor penetrates out of the first lead hole, a second lead hole is formed in the wiring shell (24), and a lead of the driving part penetrates out of the second lead hole.

3. The fully-closed miniature linear electric drive joint according to claim 1, wherein the screw (10) comprises an engagement section (111) and an actuating section (112), the engagement section (111) is in engagement with the roller (11), the actuating section (112) is fixed to one side of the engagement section (111), and the linear sensor is located between the actuating section (112) and the housing part.

4. A fully-closed miniature linear electric drive joint according to claim 3, characterized in that the length of the engagement section (111) is less than or equal to 1/5 of the length of the actuation section (112).

5. A fully closed miniature linear electric drive joint according to claim 3 or 4, characterized in that the length of the engagement section (111) is less than or equal to 1/5 of the internal thread length of the nut (12).

6. A fully closed-loop miniature linear electric drive joint according to claim 3, characterized in that the linear displacement sensor comprises a magnetic grating (25) and a reading head (26), the reading head (26) is fixed on the housing part and is electrically connected with the driving part, and the magnetic grating (25) is fixedly arranged along the length direction of the execution section (112).

7. The fully-closed miniature linear electric drive joint according to claim 6, wherein the length of the magnetic grating (25) is equal to or greater than 85% of the length of the actuating segment (112).

8. The fully-closed miniature linear electric drive joint according to claim 1, wherein a sliding bearing (27) is arranged on the shell part, at least one inner flat position is arranged on the sliding bearing (27), an outer flat position is correspondingly arranged on the screw rod (10), and the outer flat position is in abutting fit with the corresponding inner flat position.

9. A fully closed ring miniature linear electric drive joint according to claim 1, characterized in that a deep groove ball bearing (28) is arranged between the sleeve (15) and the housing part.

10. A fully closed ring miniature linear electric drive joint according to claim 1 or 9, characterized in that a four-point angular contact ball bearing (29) is arranged between the end of the screw (10) facing away from the sleeve (15) and the housing part.