CN219999186U - Motor and encoder thereof - Google Patents

Abstract

The utility model relates to a motor and an encoder thereof, wherein the encoder comprises a first code disc assembly, a second code disc assembly and a photosensitive element, the first code disc assembly comprises a first shaft sleeve and a first code disc, the first shaft sleeve is sleeved on the periphery of a rotating shaft of the motor, and the first code disc is provided with a plurality of first code channels which are mutually spaced along the circumferential direction; the second code disc assembly comprises a second sleeve and a second code disc, the second sleeve is sleeved on the periphery of the rotating shaft, and the second code disc is provided with a plurality of second code channels which are spaced from each other along the circumferential direction; the encoder is provided with a first state and a second state, when the rotating speed of the motor is smaller than or equal to the preset rotating speed, the encoder is switched from the first state to the second state, and the orthographic projection of the first code channel on the photosensitive element and the orthographic projection of the second code channel on the photosensitive element are staggered. Therefore, gaps between the first code channels and the second code channels can be fully utilized, and high-precision and high-resolution operation of the encoder can be realized when the rotating speed of the motor is smaller than or equal to the preset rotating speed.

Description

Motor and encoder thereof

Technical Field

The utility model relates to the technical field of encoders, in particular to a motor and an encoder thereof.

Background

The encoder is an angle and speed measuring device integrating light, magnetism, a machine and electricity, and converts an optical signal into an electric signal through a mechanical structure and a signal processing circuit, so that direct or indirect measurement of various physical quantities such as angular displacement, position, speed and the like is realized, and the encoder is usually arranged at the rear end position of a motor.

In the prior art, the machine tool occasion requires high positioning precision and high repetition precision, particularly in a low-speed processing state, the motor is directly connected to the screw rod of the machine tool for movement, and if a speed reducer structure is not provided, the requirement on the motor is higher. It is therefore desirable to have a high resolution, high precision encoder. However, increasing the absolute precision and resolution of the encoder requires increasing the number of physical scribe lines (code tracks) of the encoder's code wheel, but the number of physical scribe lines is limited by the capability and the technological level of the prior art, and the physical precision of the code tracks is limited; in general, if the physical accuracy is improved, the outer diameter of the code wheel is increased, but from the viewpoint of generalization and cost, motors with various calibers cannot be adapted. Therefore, how to reasonably improve the precision and resolution of the encoder is a problem to be solved.

Disclosure of Invention

The utility model provides an encoder of a motor, which aims to solve the problems of low accuracy and low resolution of the encoder when the rotating speed of the motor is low.

In a first aspect, the present utility model provides an encoder for an electric machine.

In a second aspect, the utility model provides an electric machine comprising an encoder as described above.

The encoder of the motor comprises a first code wheel assembly, wherein the first code wheel assembly comprises a first shaft sleeve and a first code wheel arranged on the first shaft sleeve, the first shaft sleeve is sleeved on the periphery of a rotating shaft of the motor, and the first code wheel is provided with a plurality of first code channels which are spaced from each other along the circumferential direction; the second code wheel assembly comprises a second sleeve and a second code wheel arranged on the second sleeve, the second sleeve is sleeved on the periphery of the rotating shaft, and the second code wheel is provided with a plurality of second code channels which are spaced from each other along the circumferential direction; the photosensitive element, the first code disc and the second code disc are sequentially arranged along the axial direction of the rotating shaft; the encoder is provided with a first state and a second state, when the rotating speed of the motor is smaller than or equal to a preset rotating speed, the encoder is switched from the first state to the second state, and the orthographic projection of the first code channel on the photosensitive element and the orthographic projection of the second code channel on the photosensitive element are staggered.

According to the encoder of the motor, when the rotating speed of the motor is smaller than or equal to the preset rotating speed, the orthographic projection of the first code wheel on the photosensitive element and the orthographic projection of the second code wheel on the photosensitive element are staggered, gaps between the first code channels and the second code channels can be fully utilized, the precision of the code wheel of the encoder is improved, high-precision operation of the motor at low speed is achieved, the resolution of the encoder can be improved, and the encoder is low in cost and good in adaptability.

In some embodiments, the encoder further comprises: the first limiting piece is arranged on one side, far away from the photosensitive element, of the first shaft sleeve; the second limiting piece is arranged on one side, far away from the photosensitive element, of the second sleeve, when the rotating speed of the motor is larger than the preset rotating speed, the encoder is switched from the second state to the first state, the first limiting piece is suitable for being matched with the second limiting piece, and the orthographic projection of the first code channel on the photosensitive element coincides with the orthographic projection of the second code channel on the photosensitive element.

In some embodiments, the encoder further comprises: the first magnetic ring and the circuit board are positioned on one side, far away from the photosensitive element, of the second code wheel assembly, and the first magnetic ring is fixed on the circuit board of the encoder and is positioned on the outer peripheral side of the rotating shaft;

the second code wheel assembly is movable along the axial direction of the rotating shaft, and the second code wheel assembly further comprises: the first coil is fixed at one end, far away from the photosensitive element, of the second sleeve, and is arranged opposite to the first magnetic ring, and attractive force is arranged between the first magnetic ring and the first coil.

In some embodiments, the second codewheel assembly further includes: the second magnetic ring and the second magnetic ring are arranged at one end of the second sleeve, which faces the photosensitive element; the first code wheel assembly further includes: the third magnetic ring is fixed at one end, far away from the photosensitive element, of the first code wheel assembly, and in the axial direction of the rotating shaft, the third magnetic ring, the second magnetic ring and the second coil are sequentially arranged, and attractive force exists between the second magnetic ring and the third magnetic ring;

when the encoder is in a first state, an attractive force between the second magnetic ring and the third magnetic ring is smaller than an attractive force between the first magnetic ring and the first coil; when the encoder is in the second state, an attractive force between the second magnetic ring and the third magnetic ring is greater than an attractive force between the first magnetic ring and the first coil.

In some embodiments, a first accommodating space and a second accommodating space are configured in the second sleeve, the first accommodating space is located on one side of the second sleeve facing away from the photosensitive element, the first coil is fixed in the first accommodating space, the second accommodating space is located on one side of the second sleeve facing toward the photosensitive element, and the second coil is fixed in the second accommodating space.

In some embodiments, the first and second accommodation spaces each have an epoxy layer therein, the epoxy layer surrounding the first and second coils to seal the first and second accommodation spaces, respectively.

In some embodiments, at least one of the first magnetic ring, the second magnetic ring, and the third magnetic ring is a ferrite piece or a neodymium-iron-boron piece.

In some embodiments, the first stop comprises a first annular ramp and the second stop comprises a second annular ramp, the first annular ramp adapted to mate with the second annular ramp when the encoder is in the first state; one of the first limiting piece and the second limiting piece is provided with a first protruding portion, the other one of the first limiting piece and the second limiting piece is provided with a first accommodating groove, and the first protruding portion is suitable for being matched in the first accommodating groove.

In some embodiments, a side of the first sleeve facing the photosensitive element has a third annular chamfer and a side of the second sleeve facing the photosensitive element has a fourth annular chamfer, the third annular chamfer being adapted to mate with the fourth annular chamfer when the encoder is in the second state.

In some embodiments, the slope of the third annular chamfer relative to the axial direction of the shaft is the same as the slope of the fourth annular chamfer relative to the axial direction of the shaft; or the inclination of the third annular inclined surface relative to the axial direction of the rotating shaft is larger than the inclination of the fourth annular inclined surface relative to the axial direction of the rotating shaft.

In some embodiments, one of the third and fourth annular ramps is provided with a second boss, and the other of the third and fourth annular ramps is provided with a second receiving slot, the second boss being adapted to fit within the second receiving slot.

In some embodiments, the second sleeve is located on an outer peripheral side of the first sleeve, and the first sleeve is slidably engaged with the second sleeve by a sliding assembly.

In some embodiments, the sliding assembly comprises a sliding rail and a sliding bearing, wherein one of the first shaft sleeve and the second shaft sleeve is provided with the sliding rail, and the other of the second shaft sleeve and the first shaft sleeve is provided with the sliding bearing, and the sliding bearing is in sliding fit with the sliding rail.

In some embodiments, the outer peripheral wall of the first sleeve is formed with a mounting groove into which the sliding assembly fits.

In some embodiments, the preset rotational speed n satisfies the relationship: n is more than 0rpm and less than or equal to 200rpm.

Additional aspects and advantages of the utility model will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the utility model.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the utility model and together with the description, serve to explain the principles of the utility model.

In order to more clearly illustrate the embodiments of the utility model or the technical solutions of the prior art, the drawings which are used in the description of the embodiments or the prior art will be briefly described, and it will be obvious to a person skilled in the art that other drawings can be obtained from these drawings without inventive effort.

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which the figures of the drawings are not to be taken in a limiting sense, unless otherwise indicated.

FIG. 1 is a cross-sectional view of an encoder according to an embodiment of the present utility model, wherein the encoder is in a first state;

FIG. 2 is a cross-sectional view of an encoder according to an embodiment of the present utility model, wherein the encoder is in a second state;

FIG. 3 is a cross-sectional view of a first code wheel assembly according to an embodiment of the present utility model;

FIG. 4 is a cross-sectional view of a second code wheel assembly according to an embodiment of the present utility model;

FIG. 5 is a top view of a portion of a first code wheel according to an embodiment of the present utility model;

FIG. 6 is a top view of a portion of a second code wheel according to an embodiment of the present utility model;

FIG. 7 is a schematic diagram of an embodiment of an orthographic projection of a first code track on a photosensitive element and an orthographic projection of a second code track on the photosensitive element, wherein an encoder is in a second state;

FIG. 8 is a top view of a second coil according to an embodiment of the present utility model;

FIG. 9 is a side view of a third annular chamfer provided in an embodiment of the present utility model;

fig. 10 is a top view of a second protruding portion and a second receiving groove according to an embodiment of the present utility model.

Reference numerals illustrate:

100. an encoder; 200. a rotating shaft;

10. a first code wheel assembly; 11. a first sleeve; 111. a third annular incline; 112. a mounting groove; 113. a first annular ramp; 114. a first sleeve portion; 115. a second sleeve portion; 116. a slot; 117. a socket; 12. a first code wheel; 121. a first code channel; 13. a third magnetic ring;

20. a second code wheel assembly; 21. a second sleeve; 211. a fourth annular incline; 212. a first accommodation space; 213. a second accommodation space; 214. a second annular ramp;

22. a second code wheel; 221. a second code channel; 23. a first coil; 24. a second coil; 25. a second magnetic ring;

30. a photosensitive element; 40. a light emitting member; 50. a first magnetic ring; 60. a circuit board; 70. a sliding assembly; 71. a slide rail; 80. a second protruding portion; 90. and a second accommodation groove.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present utility model more apparent, the technical solutions of the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model, and it is apparent that the described embodiments are some embodiments of the present utility model, but not all embodiments of the present utility model. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

The following disclosure provides many different embodiments, or examples, for implementing different structures of the utility model. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the utility model. Furthermore, the present utility model may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.

For ease of description, spatially relative terms, such as "inner," "outer," "upper," "lower," and the like, may be used herein to describe one element's or feature's relative positional relationship or movement with respect to another element's or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figure experiences a position flip or a change in attitude or a change in state of motion, then the indications of these directivities correspondingly change, for example: an element described as "under" or "beneath" another element or feature would then be oriented "over" or "above" the other element or feature. Thus, the example term "below … …" may include both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used herein interpreted accordingly.

In order to solve the technical problems of low precision and low resolution of the encoder during low-speed processing in the prior art, the utility model provides the encoder 100, which can realize high-precision and high-resolution operation of the encoder 100 when the rotating speed of a motor is low.

An encoder 100 according to an embodiment of the first aspect of the present utility model is described below with reference to fig. 1 to 10, the encoder 100 comprising: the first code wheel assembly 10, the second code wheel assembly 20 and the photosensitive element 30. In the description of the present utility model, "plurality" means two or more.

Specifically, as shown in fig. 1 to 10, the first code wheel assembly 10 includes a first shaft sleeve 11 and a first code wheel 12 provided in the first shaft sleeve 11, the first shaft sleeve 11 is sleeved on the outer circumference of a rotating shaft 200 of the motor, and the first code wheel 12 has a plurality of first code channels 121 spaced from each other in the circumferential direction. For example, the plurality of first code channels 121 are provided uniformly and at intervals in the circumferential direction of the first code wheel 12. The second code wheel assembly 20 includes a second shaft sleeve 21 and a second code wheel 22 disposed on the second shaft sleeve 21, the second shaft sleeve 21 is sleeved on the outer periphery of the rotating shaft 200, the second shaft sleeve 21 may be directly sleeved on the outer periphery of the rotating shaft 200, or may be indirectly sleeved on the outer periphery of the rotating shaft 200, for example, the first shaft sleeve 11 is sleeved on the outer periphery of the rotating shaft 200, the second shaft sleeve 21 is sleeved on the outer periphery of the first shaft sleeve 11, and both the first shaft sleeve 11 and the second shaft sleeve 21 may rotate along with the rotating shaft 200. The second code wheel 22 has a plurality of second code tracks 221 spaced apart from each other in the circumferential direction. For example, a plurality of second code channels 221 are provided uniformly and at intervals in the circumferential direction of the second code wheel 22. For example, the first code track 121 and the second code track 221 are made of opaque materials, and the first code disc body and the second code disc body are made of opaque materials, but not limited thereto.

The photosensitive element 30, the first code wheel 12, and the second code wheel 22 are sequentially arranged along the axial direction of the rotation shaft 200. The encoder 100 may further include a light emitting member 40, where the light emitting member 40 is disposed on a side of the second code wheel 22 away from the photosensitive element 30.

The encoder 100 has a first state and a second state, and when the rotational speed of the motor is less than or equal to the preset rotational speed, the encoder 100 is switched from the first state to the second state, and when the encoder 100 is in the second state, the front projection of the first code track 121 on the photosensitive element 30 and the front projection of the second code track 221 on the photosensitive element 30 are offset from each other, that is, the front projection of the first code wheel 12 on the photosensitive element 30 and the front projection of the second code track 221 on the photosensitive element 30 are alternately arranged. At this time, gaps between the plurality of first tracks 121 and the plurality of second tracks 221 may be fully utilized, so that the total number of working tracks may be increased, and thus the physical accuracy of the encoder 100 may be improved.

It can be understood that the rotating shaft 200 of the motor can drive the first code wheel 12 and the second code wheel 22 to rotate, the photosensitive element 30 arranged on the circuit board can convert the light transmission amount of the code channels of the code wheels participating in the work into a changed electric signal, and the position and the speed of the rotating shaft 200 can be recorded by recording the electric signal. When the first code wheel 12 and the second code wheel 22 work, at this time, the first code wheel 12 and the second code wheel 22 rotate along with the rotating shaft 200 of the motor.

When the rotation speed of the motor is less than or equal to the preset rotation speed, the motor is in a low-speed rotation state, and the first code wheel 12 and the second code wheel 22 work, and because the front projections of the first code channels 121 of the first code wheel 12 and the second code channels 221 of the second code wheel 22 on the photosensitive element 30 are arranged in a staggered manner, the light emitted by the light emitting element 40 can penetrate through the first code channels 121 and the second code channels 221, and the actual light transmission amount is the light transmission amount of the first code channels 121 and the light transmission amount of the second code channels 221, so that the high-precision and high-resolution operation under the low-speed state of the motor can be realized.

According to the encoder 100 of the motor in the embodiment of the present utility model, when the rotation speed of the motor is less than or equal to the preset rotation speed, the front projection of the first code wheel 12 on the photosensitive element 30 and the front projection of the second code wheel 221 on the photosensitive element 30 are dislocated, so that gaps between the first code wheel 121 and the second code wheel 221 can be fully utilized, the precision of the code wheel of the encoder 100 is increased, high-precision operation of the motor at a low speed is realized, the resolution of the encoder 100 can be improved, and the encoder is low in cost and good in adaptability.

In some embodiments, the encoder 100 includes a first limiting member and a second limiting member, the first limiting member is disposed on the first shaft sleeve 11, the second limiting member is disposed on the second shaft sleeve 21, and when the rotation speed of the motor is greater than the preset rotation speed, the encoder 100 is switched from the second state to the first state, the first limiting member is adapted to cooperate with the second limiting member, and the orthographic projection of the first code channel 121 on the photosensitive element 30 coincides with the orthographic projection of the second code channel 221 on the photosensitive element 30. By providing the first and second stoppers, the synchronous rotation of the first and second code disks 12 and 22 can be ensured, so that the orthographic projections of the first and second code tracks 121 and 221 on the photosensitive element 30 are kept in a superposed state. When the rotational speed of the motor changes, the encoder 100 may switch between a first state and a second state, enabling adaptation of the encoder 100. It is understood that the second state of the encoder 100 is a high-precision state.

When the rotating speed of the motor is larger than the preset rotating speed, the motor is in a high-speed rotating state. The photosensitive element in the prior art can be limited by the linear speed of the code wheel, so that the acquisition capacity of optical data is affected. Therefore, when the motor is operated in a high-speed state, the signal frequency is too high, the photosensitive element is often required to be customized again, the customization has the defects of high price, long period and non-universal materials, physical precision cannot be ensured, and even if a code disc manufactured by a high-precision process is used, the photosensitive element can be in downtime due to the exponentially increased sampling frequency. Therefore, in the embodiment of the present utility model, in the high-speed state, the front projection of the first code track 121 on the photosensitive element 30 coincides with the front projection of the second code track 221 on the photosensitive element 30, so that the arrangement of the second code wheel 22 at this time does not increase the total number of the working code tracks, and thus the condition that the photosensitive element 30 is down can be prevented, so as to improve the service life of the photosensitive element 30.

As shown in fig. 1 and 2, the encoder 100 further includes a first magnetic ring 50 and a circuit board 60, the circuit board 60 is located at a side of the second code wheel assembly 20 away from the photosensitive element 30, and the first magnetic ring 50 is fixed to the circuit board 60 of the encoder 100 and located at an outer peripheral side of the rotating shaft 200. It is understood that the first magnetic ring 50 does not rotate with the rotation of the rotation shaft 200. The second code wheel assembly 20 is movable in an axial direction of the rotary shaft 200 (e.g., up and down as viewed in fig. 1 and 2). The second code wheel assembly 20 further includes a first coil 23, the first coil 23 is fixed to an end of the second sleeve 21 far away from the photosensitive element 30 and is disposed opposite to the first magnetic ring 50, and an attractive force is provided between the first magnetic ring 50 and the first coil 23. Therefore, under the attraction force of the first magnetic ring 50 and the first coil 23, the second code wheel assembly 20 can move towards the first magnetic ring 50, so that the first limiting piece and the second limiting piece can be mutually matched to ensure the stability of superposition of the orthographic projection of the first code channel 121 on the photosensitive element 30 and the orthographic projection of the second code channel 221 on the photosensitive element 30.

Further, referring to fig. 1 and 2, the second code wheel assembly 20 further includes a second coil 24 and a second magnetic ring 25, and the second magnetic ring 25 and the second coil 24 are disposed at an end of the second sleeve 21 facing the photosensitive element 30. The first code wheel assembly 10 further comprises a third magnetic ring 13, the third magnetic ring 13 is fixed at one end of the first code wheel assembly 10, which is far away from the photosensitive element 30, the third magnetic ring 13, the second magnetic ring 25 and the second coil 24 are sequentially arranged in the axial direction of the rotating shaft 200, and attractive force exists between the second magnetic ring 25 and the third magnetic ring 13; when the encoder 100 is in the first state, the rotation speed of the motor is greater than the preset rotation speed, the attractive force between the second magnetic ring 25 and the third magnetic ring 13 is smaller than the attractive force between the first magnetic ring 50 and the first coil 23, and the second code wheel assembly 20 can move towards the direction of the first coil 23 until the first limiting piece and the second limiting piece cooperate and limit, so that the front projection of the first code channel 121 on the photosensitive element 30 coincides with the front projection of the second code channel 221 on the photosensitive element 30.

When the encoder 100 is in the second state, the rotation speed of the motor is less than or equal to the preset rotation speed, the attractive force between the second magnetic ring 25 and the third magnetic ring 13 is greater than the attractive force between the first magnetic ring 50 and the first coil 23, that is, when the rotation speed of the motor is changed from high speed to low speed, the second code wheel assembly 20 can move towards the third magnetic ring 13 under the action of the attractive force between the second magnetic ring 25 and the third magnetic ring 13, and the front projection of the first code channel 121 on the photosensitive element 30 and the front projection of the second code channel 221 on the photosensitive element 30 are offset, so that the accuracy of the encoder 100 in low-speed operation can be improved by utilizing the gap between the code channels.

It will be appreciated that the relationship of the orthographic projections of the first track 121 and the second track 221 on the photosensitive element 30 can be switched by the driving assembly according to the actual rotational speed of the motor. In the example of fig. 1-2, the relationship of switching the orthographic projections of the first code channel 121 and the second code channel 221 on the photosensitive element 30 according to the actual rotation speed of the motor may be achieved by the cooperation of the first coil 23, the second coil 24, the first magnetic ring 50, the second magnetic ring 25, and the third magnetic ring 13 of the driving assembly. Of course, in other examples, the switching may be performed by a crank block or the like of the drive assembly.

In some embodiments, as shown in fig. 4, a first accommodating space 212 and a second accommodating space 213 are configured in the second sleeve 21, the first accommodating space 212 is located at a side of the second sleeve 21 facing away from the photosensitive element 30, the first coil 23 is fixed in the first accommodating space 212, the second accommodating space 213 is located at a side of the second sleeve 21 facing toward the photosensitive element 30, and the second coil 24 is fixed in the second accommodating space 213. The first accommodation space 212 and the second accommodation space 213 can respectively provide the first coil 23 and the second coil 24 with magnetic fields so as to cooperate with the first magnetic ring 50 and the third magnetic ring 13 to drive the second code wheel assembly 20 to move along the axial direction of the rotating shaft 200 of the motor. Meanwhile, mounting positions can be provided for the first coil 23 and the second coil 24, and the mounting stability and the working stability of the first coil 23 and the second coil 24 are ensured, so that the working stability of the encoder 100 can be ensured.

Further, the first and second accommodation spaces 212 and 213 each have an epoxy layer therein, and the epoxy layer surrounds the first and second coils 23 and 24 to seal the first and second accommodation spaces 212 and 213. The epoxy resin has good insulating property so as to ensure the stability of the magnetic field generated by the first coil 23 and the second coil 24, and has high adhesive force and good sealing effect.

For example, at least one of the first magnetic ring 50, the second magnetic ring 25, and the third magnetic ring 13 is a ferrite piece or a neodymium iron boron piece. For example, the first magnetic ring 50, the second magnetic ring 25, and the third magnetic ring 13 may each be ferrite pieces or neodymium-iron-boron pieces. The ferrite member or the neodymium-iron-boron member has good magnetism, and can further cooperate with the first magnetic ring 50 and the third magnetic ring 13 to drive the second code wheel assembly 20 to move along the axial direction of the rotating shaft 200 of the motor, so as to control the orthographic projection relationship of the first code channel 121 and the second code channel 221 on the photosensitive element 30, and improve the self-adaptability of the encoder 100. Of course, the first coil 23 and the second coil 24 may be wound in a four-in-one manner, but the material of the first magnetic ring 50, the second magnetic ring 25 and the third magnetic ring 13 may be flexibly selected according to the actual requirement, so that the encoder 100 has higher applicability.

In some embodiments, as shown in fig. 1 and 2, the first stop includes a first annular ramp 113 and the second stop includes a second annular ramp 214, the first annular ramp 113 being adapted to mate with the second annular ramp 214 when the encoder 100 is in the first state, one of the first stop and the second stop having a first projection (not shown), the other of the first stop and the second stop having a first receiving groove (not shown), the first projection being adapted to mate within the first receiving groove. Thus, after the second code wheel assembly 20 moves towards the first magnetic ring 50, the first annular inclined surface 113 and the second annular inclined surface 214 cooperate with each other to generate a tangential force, so that the first protruding portion can be matched in the first accommodating groove, and the orthographic projections of the first code channel 121 and the second code channel 221 on the photosensitive element 30 can be kept in a superposition state.

In some embodiments, as shown in fig. 3, 4 and 9, the side of the first sleeve 11 facing the photosensitive element 30 has a third annular chamfer 111, and the side of the second sleeve 21 facing the photosensitive element 30 has a fourth annular chamfer 211, the third annular chamfer 111 being adapted to cooperate with the fourth annular chamfer 211 when the encoder 100 is in said second state. It will be appreciated that the cross-sections of the third annular inclined surface 111 and the fourth annular inclined surface 211 in the radial direction of the rotation shaft 200 are annular. When the rotation shaft 200 of the motor is switched from high rotation speed to low rotation speed, the second code wheel assembly 20 is suitable for moving towards the direction of the photosensitive element 30, and when the third annular inclined surface 111 and the fourth annular inclined surface 211 are matched and stopped, tangential force can be generated, so that the second code wheel assembly 20 rotates along the circumferential direction, and the orthographic projection of the first code wheel 12 on the photosensitive element 30 and the orthographic projection of the second code channel 221 on the photosensitive element 30 are mutually staggered, so that orthographic projection as shown in fig. 7 is formed, and high-precision operation of the motor at low rotation speed is realized.

When the third annular inclined plane 111 and the fourth annular inclined plane 211 are matched with each other, the acting force between the third annular inclined plane 111 and the fourth annular inclined plane 211 provides a tangential force to drive the second code wheel assembly 20 to rotate along the circumferential direction of the rotating shaft 200, so as to ensure that the first code wheel 12 and the second code wheel 22 work, and the orthographic projection of the first code wheel 12 on the photosensitive element 30 and the orthographic projection of the second code channel 221 on the photosensitive element 30 are misplaced with each other, thereby improving the number of code channels during low-speed rotation and improving the precision of the encoder 100.

Further, one of the third annular inclined surface 111 and the fourth annular inclined surface 211 has the second protruding portion 80, and the other of the third annular inclined surface 111 and the fourth annular inclined surface 211 has the second receiving groove 90, and the second protruding portion 80 is adapted to fit in the second receiving groove 90, whereby the orthographic projection of the first code wheel 12 on the photosensitive element 30 and the orthographic projection of the second code track 221 on the photosensitive element 30 can be offset from each other. Therefore, the relative positions of the first code wheel 12 and the second code wheel 22 in the circumferential direction can be limited, so that the second protruding portion 80 is suitable for being matched in the second accommodating groove 90, the front projection of the first code wheel 12 on the photosensitive element 30 and the front projection of the second code channel 221 on the photosensitive element 30 are offset, and the working stability of the encoder 100 at the low rotation speed of the motor is improved.

In some embodiments, the slope of the third annular chamfer 111 with respect to the axial direction of the shaft 200 is the same as the slope of the fourth annular chamfer 211 with respect to the axial direction of the shaft 200; or the inclination of the third annular inclined surface 111 with respect to the axial direction of the rotation shaft 200 is greater than the inclination of the fourth annular inclined surface 211 with respect to the axial direction of the rotation shaft 200. Both cases of this arrangement can make the cooperation of third annular inclined plane 111 and fourth annular inclined plane 211 firm, mutually in order to guarantee that first code wheel subassembly 10 and second code wheel subassembly 20 can synchronous rotation to realize the high accuracy setting of the low rotational speed of motor.

In some embodiments, the second sleeve 21 is located on the outer peripheral side of the first sleeve 11, and the first sleeve 11 is slidably engaged with the second sleeve 21 by the sliding assembly 70. The sliding assembly 70 can facilitate the movement of the second code wheel assembly 20 relative to the first code wheel assembly 10, and the second code wheel assembly 20 can be driven to move without excessively high magnetic field and attractive force variation, and the movement is stable, so that the stability of the encoder 100 is improved.

In some examples, the sliding assembly 70 includes a sliding rail 71 and a sliding bearing (not shown), one of the first sleeve 11 and the second sleeve 21 is provided with the sliding rail 71, and the other of the second sleeve 21 and the first sleeve 11 is provided with the sliding bearing, which is in sliding fit with the sliding rail 71. For example, the sliding rail 71 is disposed on the first shaft sleeve 11, the sliding bearing is disposed on the second shaft sleeve 21 to enable the sliding bearing to be in sliding fit with the sliding rail 71, and the sliding assembly 70 thus disposed slides more smoothly, so that the stability of the encoder 100 can be further improved. Of course, in other embodiments, the sliding assembly 70 may also be a combination of a sliding block and a sliding rail 71, a combination of a sliding rail 71 and a pulley, etc., which is not limited herein.

In some embodiments, the outer peripheral wall of the first sleeve 11 is formed with a mounting groove 112, and the sliding assembly 70 is fitted into the mounting groove 112. Thus, on the one hand, the mounting reliability of the slider assembly 70 can be improved, and on the other hand, the occupied space can be reduced, facilitating the miniaturization design of the encoder 100. For example, the side wall of the mounting groove 112 facing the third annular inclined plane 111 is connected with the third annular inclined plane 111, so as to further improve the smoothness of sliding of the second code wheel assembly 20, facilitate the mutual matching of the third annular inclined plane 111 and the fourth annular inclined plane 211, and ensure the matching stability of the third annular inclined plane 111 and the fourth annular inclined plane 211. For example, as shown in fig. 1 and 3, the first sleeve 11 may include a first sleeve part 114 and a second sleeve part 115, the first sleeve part 114 is located at a side of the second sleeve part 115 facing the photosensitive element 30, the first sleeve part 114 is interference-fitted with the second sleeve part 115, the mounting groove 112 may be formed on the second sleeve part 115, one of the second sleeve part 115 and the first sleeve part 114 has a slot 116, the other of the second sleeve part 115 and the first sleeve part 114 has a slot 117, and the slot 117 is in plug-fit with the slot 116 to facilitate positioning, and simultaneously, the fitting of the first sleeve part 114 and the second sleeve part 115 may be improved to be more secure.

In some embodiments, the preset rotational speed n satisfies the relationship: n is more than 0rpm and less than or equal to 200rpm. For example, the preset rotational speed n may be 0rpm < n.ltoreq.100 rpm. The preset rotation speed n may be 100rpm or may be 50rpm, and when the preset rotation speed n is within the above range, the rotation speed of the motor is lower, so that the encoder 100 may have high accuracy and good applicability.

The following describes the operation principle of the encoder 100 according to an embodiment of the present utility model with reference to fig. 1 to 10:

the first code wheel assembly 10 and the second code wheel assembly 20 may operate synchronously when the motor is operated at a low speed. When the motor enters a high-speed state from a low-speed state (for example, the motor rotating speed in the high-speed state is 100rpm-8000 rpm), the second code wheel assembly 20 and the first code wheel assembly 10 initially rotate together, wherein the first coil 23 of the second code wheel assembly 20 cuts the magnetic field of the first magnetic ring 50 to generate an induced current, and further generates an induced magnetic field in the second accommodating space 213 of the second shaft sleeve 21, the magnetic field counteracts the magnetic force of the second magnetic ring 25, and simultaneously generates a downward attractive force to attract the first magnetic ring 50; at this time, the attractive force between the first magnetic ring 50 and the first coil 23 is greater than the attractive force between the third magnetic ring 13 and the second magnetic ring 25, the second code wheel assembly 20 moves downwards until the first annular inclined surface 113 and the second annular inclined surface 214 are matched, and the first protruding part and the first accommodating groove are matched with each other to limit the relative positions of the first code wheel 12 and the second code wheel 22 in the circumferential direction, at this time, the second coil 24 starts to cut the magnetic field of the third magnetic ring 13 and counteract the magnetic field of the second magnetic ring 25; the first code wheel assembly 10 and the second code wheel assembly 20 synchronously rotate along with the rotating shaft 200, and the orthographic projections of the first code channel 121 and the second code channel 221 on the photosensitive element 30 can be kept in a superposition state.

When the motor enters into low-speed operation from a high-speed state (for example, the motor rotating speed in the low-speed state is 0-100 rpm), the second coil 24 cuts the magnetic field of the third magnetic ring 13, the induced current is reduced, the induced electromotive force is reduced, and therefore the magnetic field of the second magnetic ring 25 cannot be counteracted, the second magnetic ring 25 and the third magnetic ring 13 are attracted by the magnetic field, at the moment, the attractive force between the first magnetic ring 50 and the first coil 23 is smaller than the attractive force between the third magnetic ring 13 and the second magnetic ring 25, the second code wheel assembly 20 moves upwards until the third annular inclined surface 111 of the first shaft sleeve 11 and the fourth annular inclined surface 211 of the second shaft sleeve 21 are mutually matched, and the second code wheel assembly 20 rotates relative to the first code wheel assembly 10 along the circumferential direction, until the second protruding portion 80 and the second accommodating groove 90 are mutually matched to limit the relative positions of the first code wheel assembly 10 and the second code wheel assembly 20 in the circumferential direction, so that the code channels of the first code wheel 12 and the second code wheel 22 form a staggered structure as shown in fig. 7, the gap is fully utilized, and the first code wheel assembly 20 and the second code wheel assembly 20 rotate synchronously. The photosensitive element 30 and the like form an electric signal by the combined structure of the first code wheel 12 and the second code wheel 22.

An electric machine according to an embodiment of the second aspect of the present utility model includes the encoder 100 described in the above embodiment. According to the motor of the embodiment of the utility model, when the rotating speed of the motor is smaller than or equal to the preset rotating speed, the front projection of the first code wheel 12 on the photosensitive element 30 and the front projection of the second code channel 221 on the photosensitive element 30 are staggered, so that gaps between the first code channels 121 and the second code channels 221 can be fully utilized, the precision of the code wheel of the encoder 100 is increased, the high-precision operation of the motor at a low speed is realized, the resolution of the encoder 100 can be improved, and the cost and the adaptability are low.

Other constructions and operations of the motor, such as stator core, brake, according to embodiments of the present utility model are known to those of ordinary skill in the art and will not be described in detail herein.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "includes," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless an order of performance is explicitly stated. It should also be appreciated that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

The foregoing is only a specific embodiment of the utility model to enable those skilled in the art to understand or practice the utility model. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the utility model. Thus, the present utility model is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (16)

1. An encoder of an electric machine, comprising:

the first code wheel assembly comprises a first shaft sleeve and a first code wheel arranged on the first shaft sleeve, the first shaft sleeve is sleeved on the periphery of a rotating shaft of the motor, and the first code wheel is provided with a plurality of first code channels which are spaced from each other along the circumferential direction;

the second code wheel assembly comprises a second sleeve and a second code wheel arranged on the second sleeve, the second sleeve is sleeved on the periphery of the rotating shaft, and the second code wheel is provided with a plurality of second code channels which are spaced from each other along the circumferential direction;

the photosensitive element, the first code disc and the second code disc are sequentially arranged along the axial direction of the rotating shaft;

the encoder is provided with a first state and a second state, when the rotating speed of the motor is smaller than or equal to a preset rotating speed, the encoder is switched from the first state to the second state, and the orthographic projection of the first code channel on the photosensitive element and the orthographic projection of the second code channel on the photosensitive element are staggered.

2. The encoder of an electric machine of claim 1, further comprising:

the first limiting piece is arranged on one side, far away from the photosensitive element, of the first shaft sleeve;

the second limiting piece is arranged on one side, far away from the photosensitive element, of the second sleeve, when the rotating speed of the motor is larger than the preset rotating speed, the encoder is switched from the second state to the first state, the first limiting piece is suitable for being matched with the second limiting piece, and the orthographic projection of the first code channel on the photosensitive element coincides with the orthographic projection of the second code channel on the photosensitive element.

3. The encoder of an electric machine of claim 2, wherein the encoder further comprises: the first magnetic ring and the circuit board are positioned on one side, far away from the photosensitive element, of the second code wheel assembly, and the first magnetic ring is fixed on the circuit board of the encoder and is positioned on the outer peripheral side of the rotating shaft;

the second code wheel assembly is movable along the axial direction of the rotating shaft, and the second code wheel assembly further comprises:

the first coil is fixed at one end, far away from the photosensitive element, of the second sleeve, and is arranged opposite to the first magnetic ring, and attractive force is arranged between the first magnetic ring and the first coil.

4. The encoder of the electric machine of claim 3, wherein the second code wheel assembly further comprises:

the second coil and the second magnetic ring are arranged at one end of the second sleeve, which faces the photosensitive element;

the first code wheel assembly further includes: the third magnetic ring is fixed at one end, far away from the photosensitive element, of the first code wheel assembly, and in the axial direction of the rotating shaft, the third magnetic ring, the second magnetic ring and the second coil are sequentially arranged, and attractive force exists between the second magnetic ring and the third magnetic ring;

when the encoder is in the first state, an attractive force between the second magnetic ring and the third magnetic ring is smaller than an attractive force between the first magnetic ring and the first coil; when the encoder is in the second state, an attractive force between the second magnetic ring and the third magnetic ring is greater than an attractive force between the first magnetic ring and the first coil.

5. The motor encoder of claim 4, wherein a first accommodation space and a second accommodation space are configured in the second sleeve, the first accommodation space being located on a side of the second sleeve facing away from the photosensitive element, the first coil being fixed in the first accommodation space, the second accommodation space being located on a side of the second sleeve facing toward the photosensitive element, the second coil being fixed in the second accommodation space.

6. The motor encoder of claim 5, wherein the first and second receiving spaces each have an epoxy layer therein, the epoxy layer surrounding the first and second coils to seal the first and second receiving spaces, respectively.

7. The encoder of the electric machine of claim 4, wherein at least one of the first magnetic ring, the second magnetic ring, and the third magnetic ring is a ferrite piece or a neodymium iron boron piece.

8. An encoder for an electric machine according to claim 7, characterized in that,

the first limiting piece comprises a first annular inclined surface, the second limiting piece comprises a second annular inclined surface, and when the encoder is in the first state, the first annular inclined surface is suitable for being matched with the second annular inclined surface;

one of the first limiting piece and the second limiting piece is provided with a first protruding portion, the other one of the first limiting piece and the second limiting piece is provided with a first accommodating groove, and the first protruding portion is suitable for being matched in the first accommodating groove.

9. The encoder of the motor of claim 1, wherein a side of the first sleeve facing the photosensitive element has a third annular chamfer and a side of the second sleeve facing the photosensitive element has a fourth annular chamfer, the third annular chamfer being adapted to mate with the fourth annular chamfer when the encoder is in the second state.

10. The encoder of an electric machine according to claim 9, wherein a slope of the third annular chamfer with respect to an axial direction of the shaft is the same as a slope of the fourth annular chamfer with respect to the axial direction of the shaft; or (b)

The inclination of the third annular inclined surface with respect to the axial direction of the rotating shaft is larger than the inclination of the fourth annular inclined surface with respect to the axial direction of the rotating shaft.

11. The motor encoder of claim 9, wherein one of the third and fourth annular ramps is provided with a second boss, and the other of the third and fourth annular ramps is provided with a second receiving groove, the second boss being adapted to fit within the second receiving groove.

12. The motor encoder of claim 9, wherein the second sleeve is located on an outer peripheral side of the first sleeve, the first sleeve being in sliding engagement with the second sleeve by a sliding assembly.

13. The motor encoder of claim 12, wherein the sliding assembly includes a sliding rail and a sliding bearing, wherein one of the first sleeve and the second sleeve is provided with a sliding rail, and the other of the second sleeve and the first sleeve is provided with a sliding bearing, and wherein the sliding bearing is in sliding engagement with the sliding rail.

14. The encoder of a motor of claim 12, wherein the outer peripheral wall of the first sleeve is formed with a mounting groove, the sliding assembly being fitted in the mounting groove.

15. The encoder of an electric machine according to claim 1, characterized in that the preset rotation speed n satisfies the relation: n is more than 0rpm and less than or equal to 200rpm.

16. An electric machine comprising an encoder according to any one of claims 1-15.