ROTOR MOTOR FOR LIDAR AND LIDAR

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Chinese Patent Application No. 202111447141.4, filed December 1, 2021, entitled “A DOUBLE-SIDED DYNAMIC BALANCE WEIGHTINCREASING LIDAR OUTER ROTOR MOTOR AND LIDAR,” the content of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present application relates to the technical field of lidars, and in particular to a doublesided dynamically balanced weight-increasing outer rotor motor for a lidar and a lidar having the outer rotor motor.

BACKGROUND

A lidar is a radar system which measures the features of a target, such as position, speed, etc., by transmitting a laser beam. The operating principle of the lidar is as follows: a detection signal ( a laser beam) is transmitted to a target, and then a received signal (a target echo) reflected from the target is compared with the transmitted signal and appropriately processed to obtain the relevant information of the target, such as distance, orientation, height, speed, attitude, even shape, etc., so as to detect, track and identify the target.

The lidar mainly comprises a housing, a motor, and an optical mirror. An outer rotor motor is usually adopted as the motor, which mainly comprises a motor shaft, a stator assembly fixedly mounted on the motor shaft, a rotor assembly rotatably mounted on the motor shaft, and bottom cases fixedly mounted at two ends of the motor shaft. The rotor assembly comprises bearings mounted on the shaft and a rotor housing or rotor yoke mounted outside the bearing. The optical mirror is mounted on the periphery of the rotor assembly.

The optical mirror of the lidar is typically driven by a motor to rotate, that is, the optical mirror is a part of the outer rotor of the motor. As well-known, to reduce the vibration noise of the motor and guarantee the reliability of a motor product, it is necessary to dynamically balance the rotor of the motor. At present, the conventional methods of dynamic balance include weight- increasing method and weight-decreasing method. The weight-decreasing is usually implemented by mechanical drilling or milling. The weight-increasing is usually implemented by providing a dynamically balancing aid on the motor or providing a balancing plate on the end. However, due to the compact structure of the motor for a lidar and the limit of the increased weight, the dynamic balance is hard to control by using the dynamically balancing aid or the balancing plate to increase weight.

SUMMARY

In view of the above-mentioned technical problems, an objective of the present application is to provide a double-sided dynamically balanced weight-increasing outer rotor motor for a lidar, and a lidar to reduce the difficulty in weight-increasing balance of the motor for a lidar and solve the problem in the prior art that the dynamic balance is hard to control by using the dynamically balancing aid or the balancing plate to increase weight due to the compact structure of the lidar.

The technical solutions of the present application are as follows.

One objective of the present application is to provide a double-sided dynamically balanced weight-increasing outer rotor motor for a lidar, which comprises: a motor shaft; bearings sleeved on the motor shaft; a rotor yoke arranged on the periphery of the bearings, wherein the rotor yoke has a first end and a second end which are opposite in the axial direction, the end face of the second end is provided with a plurality of second counterweight holes distributed circumferentially; a pressing plate sleeved on the periphery of the first end of the rotor yoke to press an optical mirror against the rotor yoke, where the end face of the pressing plate away from the second end of the rotor yoke is provided with a plurality of first counterweight holes distributed circumferentially, and wherein some of or all of the first counterweight holes and the second counterweight holes are internally provided with counterweights.

Optionally, some of or all of the first counterweight holes and the second counterweight holes are internally provided with counterweights.

Optionally, the counterweights are fixed in the first counterweight holes and the second counterweight holes with glue. Optionally, the first counterweight holes and the second counterweight holes are blind holes.

Optionally, the peripheral wall of the rotor yoke is provided with a first step surface and a second step surface in the direction from the first end to the second end, and the optical mirror is sleeved on the periphery of the rotor yoke and lapped on the second step surface; the axial inner end face of the pressing plate is radially provided with a third step surface and a fourth step surface from inside to outside, the third step surface faces the first step surface, and the fourth step surface presses against the optical mirror.

Optionally, a buffer is arranged between the fourth step surface and the optical mirror.

Optionally, the fourth step surface is provided with corrugations.

Optionally, the outer rotor motor further comprises a top case and a bottom case, wherein the top case is fixed to one end of the motor shaft by screws, and the bottom case is in interference fit with the other end of the motor shaft.

Another objective of the present application is to provide a lidar, comprising an optical mirror and a double-sided dynamically balanced weight-increasing outer rotor motor for a lidar according to any one of the embodiments, wherein the optical mirror is sleeved on the periphery of the rotor yoke and is pressed by the pressing plate.

Compared with the prior art, the present application has the following advantages.

According to a double-sided dynamically balanced weight-increasing outer rotor motor for a lidar of the present application, the counterweight holes are provided in both the rotor yoke and the pressing plate, that is, the counterweight holes are provided at two sides inside the motor, thus a double-sided weight-increasing dynamic balance could be realized by arranging the counterweights in the counterweight holes. The outer rotor motor has a simple structure and is easy and convenient to make an adjustment. The problem in the prior art that the dynamic balance is hard to control by using the dynamically balancing aid or the balancing plate to increase weight due to the compact structure of the lidar is solved.

BRIEF DESCRIPTION OF THE DRAWINGS

The present application will be further described below with reference to the accompanying drawings and the embodiments.

FIG. 1 is a schematic sectional view of a double-sided dynamically balanced weight- increasing outer rotor motor for a lidar according to an embodiment of the present application.

FIG. 2 is a schematic top view of the double-sided dynamically balanced weight-increasing outer rotor motor for a lidar in FIG. 1 (with the top case omitted).

FIG. 3 is a schematic bottom view of a double-sided dynamically balanced weightincreasing outer rotor motor for a lidar according to an embodiment of the present application (with the bottom case omitted).

FIG. 4 is a schematic structural view of a pressing plate of a double-sided dynamically balanced weight-increasing outer rotor motor for a lidar according to an embodiment of the present application.

FIG. 5 is a schematic structural view of a rotor yoke of a double-sided dynamically balanced weight-increasing outer rotor motor for a lidar according to an embodiment of the present application.

Reference numerals: 1, motor shaft; 2, bearing; 3, pressing plate; 31, first counterweight hole; 32, third step surface; 33, fourth step surface; 4, rotor yoke; 41, second counterweight hole; 42, first step surface; 43, second step surface; 5, top case; 6, bottom case; 7, optical mirror.

DETAILED DESCRIPTION OF EMBODIMENTS

In order to illustrate the objectives, technical solutions and advantages of the present application more clearly, the present application will be further described in detail below with reference to the embodiments and the accompanying drawings. It should be understood that the descriptions are merely exemplary instead of limiting the scope of the present invention. Moreover, in the following specification, the description of well-known structures and techniques are omitted to avoid unnecessarily confusing the concept of the present invention.

As shown in FIGS. 1 to 5, a double-sided dynamically balanced weight-increasing outer rotor motor for a lidar of the present embodiment comprises a motor shaft 1 , bearings 2, a rotor yoke 4, a pressing plate 3, a stator assembly, rotor magnet steel, a top case 5, and a bottom case 6. The bearings 2 are sleeved on the motor shaft 1, and the number of the bearings is two. The rotor yoke 4 is sleeved on the periphery of the bearings 2, and the outer wall of the rotor yoke 4 is in the form of steps. The rotor yoke 4 has a first end, namely the upper end as shown in FIG. 1, and a second end, namely the lower end as shown in FIG. 1 , which are opposite in the axial direction. The stator assembly is sleeved on the motor shaft 1 and located at the end of the motor shaft 1 close to the second end of the rotor yoke 4, and the inner wall of the second end of the rotor yoke 4 is provided with a rotor magnet steel opposite to the stator assembly. The pressing plate 3 is sleeved on the periphery of the first end of the rotor yoke 4 and presses against an optical mirror 7 fitting on the periphery of the rotor yoke 4. The top case 5 is fixed to the end of the motor shaft 1 close to the first end of the rotor yoke 4 by screws, and the bottom case 6 is fixed to the end of the motor shaft 1 close to the second end of the rotor yoke 4 by interference fit. The end face of the second end of the rotor yoke 4 is provided with a plurality of second counterweight holes 41 distributed circumferentially. The end face of the pressing plate 3 away from the second end of the rotor yoke 4, namely the upper end face of the pressing plate 3 as shown in FIG. 1 , is provided with a plurality of first counterweight holes 31 distributed circumferentially. Optionally, some of or all of the first counterweight holes 31 and the second counterweight holes 41 are internally provided with counterweights. According to the embodiment, the problem in the prior art that the dynamic balance is hard to control by using the dynamically balancing aid or the balancing plate to increase weight due to the compact structure of the lidar is solved. According to the present invention, the counterweight holes are provided in both the rotor yoke 4 and the pressing plate 3, that is, the counterweight holes are provided at two sides inside the motor, thus a double-sided weight-increasing dynamic balance could be realized by arranging counterweights in the counterweight holes. The outer rotor motor according to the embodiment has a simple structure and facilitates the control of the dynamical balance.

According to some preferred embodiments of the present application, as shown in FIGS. 1 to 3, the first counterweight holes 31 and the second counterweight holes 41 are blind holes. In an optional embodiment, the first counterweight holes 31 and the second counterweight holes 41 are threaded holes, and the counterweights are screws. Using the threaded connection to increase weight and achieve the overall balance of the motor is simple and convenient. The inner walls of the first counterweight holes 31 and the second counterweight holes 41 may also be smooth. Correspondingly, the counterweights may be cylindrical counterweight blocks, such as copper counterweight blocks. The counterweights could be fixed in the counterweight holes with glue to increase weight and achieve the overall balance of the motor. As an alternative embodiment, the first counterweight holes 31 and the second counterweight holes 41 may be through holes instead of blind holes.

The first counterweight holes 31 and the second counterweight holes 41 could be processed by laser ablation or by conventional mechanical drilling or milling. The processing methods are not specifically described and limited and may be selected by the skilled in the art according to actual needs. The aperture and quantity of the first counterweight holes 31 and the second counterweight holes 41 are not specifically limited and are determined depending on the thickness of the second end of the rotor yoke 4 and the rear end of the upper end face of the pressing plate 3. In this embodiment, the diameter of the circle enclosed by the first counterweight holes 31 in the pressing plate 3 is greater than that of the circle enclosed by the second counterweight holes 41 in the second end of the rotor yoke 4, and the quantity of the first counterweight holes 31 is larger than that of the second counterweight holes 41.

For the structure of the rotor yoke 4, as shown in FIGS. 1 and 5, the peripheral wall of the rotor yoke 4 is provided with a first step surface 42 and a second step surface 43 in the direction from the first end to the second end, namely the direction from the upper side to the lower side as shown in FIG. 1, and the optical mirror 7 is sleeved on the periphery of the rotor yoke 4 and is lapped on the second step surface 43. As shown in FIGS. 1 and 4, the axial inner end face of the pressing plate 3, namely the lower end face of the pressing plate 3 as shown in FIG. 1, is radially provided with a third step surface 32 and a fourth step surface 33 from inside to outside, the third step surface 32 faces the first step surface 42, and the fourth step surface 33 presses against the optical mirror 7. Preferably, a buffer, such as rubber and sponge, etc., is arranged between the fourth step surface 33 and the optical mirror 7. Preferably, the fourth step surface 33, particularly the surface in contact with the buffer, is provided with several circles of corrugations to increase the pressing force between the pressing plate 3 and the optical mirror 7.

An embodiment of the present application further provides a lidar, comprising an optical mirror 7 and the double-sided dynamically balanced weight-increasing outer rotor motor for a lidar of the above embodiments, wherein the optical mirror 7 fits with and is fixed to the periphery of the rotor yoke 4 by the press of the pressing plate 3. Since the outer rotor motor of the above embodiments is adopted, the lidar has at least the beneficial effects of the outer rotor motor of the above embodiments.

It should be understood that the above specific embodiments of the present application are merely used for illustration or explanation of the principle of the present application, and are not construed as limiting the present application. Therefore, any modifications, equivalent substitutions, improvements, etc., made without deviating from the spirit and scope of the present application should fall within the scope of protection of the present application. In addition, the appended claims of the present application are intended to include all the variations and modifications that fall within the scope and boundary of the appended claims or equivalents of the scope and boundary.