Full-closed-loop miniature linear electric drive joint

Abstract

The utility model relates to the technical field of mechanical joints, in particular to a full-closed-loop miniature linear electric drive joint which comprises a shell part, a motor part, a roller lead screw part and a drive part. In order to solve the technical problem that an existing linear electric drive joint has defects, a planetary roller lead screw mechanism is utilized, the bearing capacity is greatly improved, and the service life of the whole actuator is prolonged; the connection mode of the motor and the planetary roller lead screw mechanism is improved, the axial size is greatly shortened, and the unit power-to-weight ratio is increased; and moreover, 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.

Description

TECHNICAL FIELD

[0001] The utility model relates to mechanical joint technical field, concretely relates to a kind of full closed loop miniature linear electric drive joints. BACKGROUND

[0002] The current conventional miniature linear electric drive joint usually adopts ball screw or sliding screw, and is basically designed as motor output and screw fixed connection, screw rotation, nut linear motion.But using ball screw, there is the defect of small bearing capacity and low output force;And using sliding screw, there is the defect of large friction and low efficiency.

[0003] And, the integration of the existing miniature linear electric drive joint is not high, for example, the output end linear encoder is not integrated with the screw, and the motor and the screw need to be connected by spline or other ways, and low integration will limit the upper limit of precision, so that it cannot be applied to high-precision mechanical joints. UTILITY MODEL CONTENTS

[0004] In view of the technical problems that the existing linear electric drive joint has defects, the utility model provides a kind of full closed loop miniature linear electric drive joint, which utilizes planetary roller screw mechanism, greatly improves bearing capacity, prolongs the service life of the whole actuator, improves the connection mode of motor and planetary roller screw mechanism, greatly shortens the axial size, and improves the unit power ratio;And the rotary encoder and linear displacement sensor are integrated with the planetary roller screw mechanism, full closed loop control is realized, and the positioning accuracy is improved.

[0005] The technical scheme provided by the utility model is as follows: a kind of full closed loop miniature linear electric drive joint, including shell part, motor part, roller screw part and drive part;The roller screw part is located in the inner side of the shell part, the roller screw part includes screw, roller and nut, a plurality of rollers are surrounded on the outer side of the screw and engaged with the screw, the nut is located on the outer side of the roller and engaged with the roller;The motor part includes stator and rotor, the stator is fixed in the inner side of the shell part, the rotor is located in the inner side of the stator, and the rotor is fixed on the outer side of the nut;The drive part is located in the shell part, one end of the roller screw part is sleeved with sleeve, magnetic head is arranged on the sleeve, the drive part includes code disc, the magnetic head and code disc constitute rotary encoder;Linear displacement sensor is arranged between the screw and the shell part;One end of the shell part is fixedly provided with ball bearing, the ball bearing is integrated with push-pull force sensor;The motor part, rotary encoder, linear displacement sensor and push-pull force sensor are electrically connected with the drive part.

[0006] Optionally, the shell part comprises a first end cover, a main shell, a wiring shell and a second end cover, the first end cover and the wiring shell are fixed at two ends of the main shell respectively, and the second end cover is fixed at one end of the wiring shell away from the main shell; the lead wire hole is arranged on the first end cover, and the lead wire of the linear displacement sensor passes out from the first lead wire hole; the second lead wire hole is arranged on the wiring shell, and the lead wire of the driving part passes out from the second lead wire hole.

[0007] Optionally, the screw rod comprises an engaging section and an execution section, the engaging section is engaged with the roller, and the execution section is fixed to one side of the engaging section; the linear displacement sensor is located between the execution section and the shell part.

[0008] Optionally, the length of the engaging section is less than or equal to 1 / 5 of the length of the execution section.

[0009] Optionally, the length of the engaging section is less than or equal to 1 / 5 of the length of the internal thread of the nut.

[0010] Optionally, the linear displacement sensor comprises a magnetic grid and a reading head, the reading head is fixed to the shell part and electrically connected with the driving part, and the magnetic grid is fixed along the length direction of the execution section.

[0011] Optionally, the length of the magnetic grid is greater than or equal to 85% of the length of the execution section.

[0012] Optionally, the shell part is provided with a sliding bearing, at least one inner flat position is arranged on the sliding bearing, and an outer flat position is correspondingly arranged on the screw rod, and the outer flat position is in abutting cooperation with the corresponding inner flat position.

[0013] Optionally, a deep groove ball bearing is arranged between the sleeve and the shell part.

[0014] Optionally, a four-point angular contact ball bearing is arranged between one end of the screw rod away from the sleeve and the shell part.

[0015] Beneficial effects

[0016] Compared with the prior art, the technical scheme has the following beneficial effects: in view of the technical problems of defects existing in the existing linear electric drive joint, the planetary roller screw mechanism is used, the bearing capacity is greatly improved, and the service life of the entire actuator is prolonged; the connection mode of the motor and the planetary roller screw mechanism is improved, the axial size is greatly shortened, and the unit power weight ratio is improved; the rotary encoder and the linear displacement sensor are highly integrated with the planetary roller screw mechanism, full closed-loop control is realized, and the positioning accuracy is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The structural schematic diagram of the full-closed loop micro linear electric driving joint is provided for the embodiments of the utility model. DETAILED DESCRIPTION

[0018] In order to further understand the content of the utility model, the utility model is described in detail in combination with the drawings and embodiments.

[0019] The application will be described in further detail below in combination with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related utility model, and not to limit the utility model. In addition, it should be noted that only the parts related to the utility model are shown in the drawings for convenience of description. The first, second and the like in the utility model are set for the convenience of describing the technical scheme of the utility model, and do not have a specific limiting effect, and are generic, and do not constitute a limiting effect on the technical scheme of the utility model. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict. In the description of the utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the utility model. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. Unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium, or it can be the communication between two elements. For ordinary skilled persons in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances. The multiple technical schemes in the same embodiment, and the multiple technical schemes of different embodiments can be arranged and combined to form new technical schemes without contradiction or conflict, which are within the scope of protection of the utility model.

[0020] Embodiment 1

[0021] In combination with the drawings, Figure 1 The embodiment provides a full-closed loop micro linear electric driving joint, which comprises a shell part, a motor part, a roller screw part and a driving part.

[0022] The roller screw part is located inside the shell part, and the roller screw part comprises a screw rod 10, a roller 11 and a nut 12, a plurality of rollers 11 are arranged around the outside of the screw rod 10 and engaged with the screw rod 10, and the nut 12 is located outside the roller 11 and engaged with the roller 11.

[0023] The motor part comprises a stator 13 and a rotor 14, the stator 13 is fixed inside the shell part, the rotor 14 is located inside the stator 13, and the rotor 14 is fixed outside the nut 12.

[0024] The driving part is located inside 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, and the magnetic head 16 and the code disc 17 constitute a rotary encoder; a linear displacement sensor is arranged between the screw rod 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 electrically connected with the driving part.

[0025] Based on the above-mentioned structural features, the working principle of the full-closed loop micro linear electric drive joint in the embodiment is that the planetary roller screw mechanism composed of the screw rod 10, the roller 11 and the nut 12 is provided with threads on the inside of the nut 12, threads and gears on the roller 11, and threads and gears on the screw rod 10. The nut 12 is engaged with the roller 11 through threads, and the roller 11 is engaged with the screw rod 10 through threads and gears.

[0026] In the motor part, the stator 13 can drive the rotor 14 to rotate the nut 12, based on the above-mentioned engagement relationship, the rotation of the nut 12 can drive the screw rod 10 to move linearly, when applied to products such as a mechanical hand, the linear motion of the screw rod 10 can drive the movement of the finger joints in the mechanical hand.

[0027] The movement of the screw rod 10 is controlled by the motor part, and the motor part is controlled through the driving part. In the embodiment, the driving part is arranged in the shell part, close to the end of the roller screw part.

[0028] The driving part comprises relevant hardware circuit and motor driving circuit, and also comprises the code disc 17, the end of the roller screw part is sleeved with the sleeve 15, that is, the sleeve 15 is fixed outside the nut 12, the sleeve 15 can rotate with the rotation of the nut 12, the 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 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 the rotary electric signal.

[0029] And, a linear displacement sensor is arranged between the lead screw 10 and the housing part, and can read the linear displacement of the lead screw 10. In addition, a ball bearing 18 is fixedly arranged at one end of the housing part, and is used to connect with external mechanisms, such as components of a robot hand, and can offset most of the non-axial force. The ball bearing 18 is integrated with a push-pull force sensor, and can collect push-pull force electrical signals.

[0030] Based on the arrangement of the rotary encoder, the linear displacement sensor and the push-pull force sensor, the driving part can change the working condition of the motor part by combining the electrical signals collected by these sensors, so as to change the working condition of the lead screw 10.

[0031] In a more preferred embodiment, the housing part includes a first end cover 21, a main housing 23, a wiring housing 24 and a second end cover 22, the first end cover 21 and the wiring housing 24 are respectively fixed to both ends of the main housing 23, and the second end cover 22 is fixed to one end of the wiring housing 24 away from the main housing 23. The lead screw 10 penetrates through the first end cover 21, and the first end cover 21 is provided with a first lead hole through which the lead wire of the linear displacement sensor penetrates; the wiring housing 24 is provided with a second lead hole through which the lead wire of the driving part penetrates. In this embodiment, the housing part is composed of multiple parts, and this combination form is helpful to improve the convenience of assembly. In addition, the first lead hole and the second lead hole are reserved to facilitate the connection between the internal circuit and the outside.

[0032] In another preferred embodiment, the lead screw 10 includes an engagement section 111 and an execution section 112, the engagement section 111 is engaged with the roller 11, and the execution section 112 is fixed to one side of the engagement section 111, and the linear displacement sensor is located between the execution section 112 and the housing part. In this way, the lead screw 10 is divided into two parts, the engagement section 111 is used for engagement with the roller 11, and the execution section 112 is mainly used as a part connected with the outside and does not participate in the engagement. In this way, only part of the lead screw 10 is used for engagement transmission, and only part of the lead screw 10 is used for external output, which can improve the overall service life to a certain extent, and also can reduce the processing cost.

[0033] In a further embodiment, the length of the engagement section 111 is less than or equal to 1 / 5 of the length of the execution section 112, so that the engagement section 111 can realize the movement of the execution section 112 with a larger stroke by a smaller engagement area, and improve the overall use efficiency.

[0034] In another improved way similar to the above embodiment, the length of the engagement section 111 is less than or equal to 1 / 5 of the length of the internal thread of the nut 12. The purpose is also to reduce the engagement length of the lead screw 10, so that the execution section 112 of the lead screw 10 has as large a movement stroke as possible, and the overall use efficiency is improved.

[0035] On the basis that the screw 10 is divided into the execution section 112 and the meshing section 111, there is another preferred embodiment: the linear displacement sensor comprises a magnetic grid 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 grid 25 is fixedly arranged along the length direction of the execution section 112. Wherein, the reading head 26 can be fixed on the housing part near the region through which the execution section 112 penetrates. In this embodiment, the integration of the linear displacement sensor is further realized, and this arrangement can more accurately read the position signal of the screw 10 in the linear motion process.

[0036] In a further embodiment, the length of the magnetic grid 25 is greater than or equal to 85% of the length of the execution section 112. The setting length of the magnetic grid 25 can be understood as the effective length of the output of the screw 10, so the effective length of the output should be as long as possible, preferably greater than or equal to 85% of the length of the execution section 112.

[0037] In addition, in a preferred embodiment, a sliding bearing 27 is arranged on the housing part, at least one inner flat position is arranged on the sliding bearing 27, and a corresponding outer flat position is arranged on the screw 10, and the outer flat position is in abutting cooperation with the corresponding inner flat position. In this embodiment, the screw 10 is provided with one or four or other number of outer flat positions, and the sliding bearing 27 is provided with corresponding inner flat positions, and the inner flat positions and the outer flat positions are in cooperation with each other to realize the anti-rotation function. And the arrangement of the sliding bearing 27 can reduce the wear between the screw 10 and the housing part.

[0038] In addition, in order to ensure the smoothness and stability of the rotation of the nut 12, a deep groove ball bearing 28 can be arranged between the sleeve 15 and the housing part. Similarly, a four-point angular contact ball bearing 29 can also be arranged between the screw 10 away from the sleeve 15 and the housing part to bear the axial and radial load.

[0039] In summary, in view of the technical problems of the existing linear electric drive joint, the full-closed-loop micro linear electric drive joint provided in the embodiment uses the planetary roller screw mechanism, which can greatly improve the carrying capacity and prolong the service life of the entire actuator; and improves the connection mode of the motor and the planetary roller screw mechanism, greatly shortens the axial size, and improves the unit power weight ratio; and the rotary encoder and the linear displacement sensor are highly integrated with the planetary roller screw mechanism, realizing full-closed-loop control and improving the positioning accuracy.

[0040] The utility model is described above and its embodiments are described schematically, which is not restrictive, and the drawings only show one of the embodiments of the utility model, and the actual structure is not limited thereto. Therefore, if a person skilled in the art is inspired by the utility model, without departing from the utility model, similar structural modes and embodiments are designed without creativity, which should belong to the protection scope of the utility model.

Claims

1. A fully closed-loop miniature linear electrically driven joint, characterized in that, It includes a housing, a motor, a ball screw, and a drive unit; The ball screw section is located inside the housing section. The ball screw section includes a screw (10), rollers (11) and a nut (12). A plurality of rollers (11) surround the outside of the screw (10) and mesh with the screw (10). The nut (12) is located outside the rollers (11) and meshes with the rollers (11). The motor unit includes a stator (13) and a rotor (14). The stator (13) is fixed inside the housing unit, the rotor (14) is located inside the stator (13), and the rotor (14) is fixed outside the nut (12). The drive unit is located inside the housing. One end of the ball screw is fitted with a sleeve (15), and a magnetic head (16) is provided on the sleeve (15). The drive unit includes a code disk (17), and the magnetic head (16) and the code disk (17) constitute a rotary encoder. A linear displacement sensor is provided between the ball screw (10) and the housing. A ball bearing (18) is fixedly provided at one end of the housing, and the ball bearing (18) integrates a push-pull force sensor. The motor, rotary encoder, linear displacement sensor, and push-pull force sensor are all electrically connected to the drive unit.

2. The fully closed-loop miniature linear electrically driven joint according to claim 1, characterized in that, The housing includes a first end cap (21), a main housing (23), a wiring housing (24), and a second end cap (22). The first end cap (21) and the wiring housing (24) are respectively fixed to both ends of the main housing (23), and the second end cap (22) is fixed to one end of the wiring housing (24) away from the main housing (23). The lead screw (10) passes through the first end cover (21), and the first end cover (21) is provided with a first lead hole, through which the lead of the linear displacement sensor passes; the wiring housing (24) is provided with a second lead hole, through which the lead of the drive unit passes.

3. The fully closed-loop miniature linear electrically driven joint according to claim 1, characterized in that, The lead screw (10) includes an engagement section (111) and an execution section (112). The engagement section (111) engages with the roller (11). The execution section (112) is fixed to one side of the engagement section (111). The linear position sensor is located between the execution section (112) and the housing.

4. The fully closed-loop miniature linear electrically driven 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 execution section (112).

5. A fully closed-loop miniature linear electrically driven 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 length of the internal thread of the nut (12).

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

7. A fully closed-loop miniature linear electrically driven joint according to claim 6, characterized in that, The length of the magnetic grating (25) is greater than or equal to 85% of the length of the execution segment (112).

8. A fully closed-loop miniature linear electrically driven joint according to claim 1, characterized in that, A sliding bearing (27) is provided on the housing part, and at least one inner flat part is provided on the sliding bearing (27). A corresponding outer flat part is provided on the lead screw (10), and the outer flat part abuts and cooperates with the corresponding inner flat part.

9. A fully closed-loop miniature linear electrically driven joint according to claim 1, characterized in that, A deep groove ball bearing (28) is provided between the sleeve (15) and the housing portion.

10. A fully closed-loop miniature linear electrically driven joint according to claim 1 or 9, characterized in that, A four-point angular contact ball bearing (29) is provided between the end of the lead screw (10) away from the sleeve (15) and the housing.

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