CN211046637U - Low axial float motor - Google Patents

Abstract

The utility model relates to a low axial float motor, including front end housing, rear end cap, stator, rotor (4) and bearing, the bearing but pretension bearing (2), rotor (4) both ends fix in the bearing chamber of front and rear end cap through a pair of pretension bearing (2), but pretension bearing (2) on be equipped with the mechanism that provides the pretightning force. Compared with the prior art, the utility model has the advantages of reduce the axial float by a wide margin, increase axial load capacity, extension motor life.

Description

Low axial float motor

Technical Field

The utility model relates to a motor especially relates to a low axial float motor.

Background

The stepping motor or the brushless motor is used as a basic power unit in the motion control field, and has great use requirements in various fields. With the development of industry, the demand of precision production is higher and higher, and the demand of high precision for position control is higher and higher, especially when a stepping motor or a brushless motor is used in combination with a screw rod and provides axial linear motion, many factors influencing the axial linear motion need to be considered.

For a conventional motor, the motor itself is often subjected to a certain axial force and then to a certain axial displacement. However, in terms of the structure of the motor, the rotor is usually fixed in the bearing chamber of the end cover by bearings at both ends, wherein no significant mechanical clearance exists. The axial displacement is mainly caused by the elastic deformation of the mechanical structure and the play in the bearing.

At present micro motor is mostly the latch segment and uses with the cooperation of deep groove ball bearing, exerts the pretightning force to the bearing through latch segment and gasket to reduce the bearing play. However, the deep groove ball bearing is not a clearance adjusting bearing, and when the pretightening force is too large, the bearing resistance is larger than the motor output torque, so that the locking is caused.

SUMMERY OF THE UTILITY MODEL

The present invention aims to overcome the above-mentioned drawbacks of the prior art and to provide a low axial play motor.

The purpose of the utility model can be realized through the following technical scheme:

a low axial float motor comprises a front end cover, a rear end cover, a stator, a rotor and bearings, wherein the bearings can be pre-tightened, two ends of the rotor are fixed in bearing chambers of the front end cover and the rear end cover through a pair of pre-tightened bearings, and a mechanism for providing pre-tightening force is arranged on the pre-tightened bearings.

Preferably, the mechanism for providing the pretightening force comprises a locking block and an elastic component, the elastic component is installed between the locking block and the bearing capable of pretightening, and the motor positioning torque is controlled by adjusting the size of the pretightening force through adjusting the locking block.

Preferably, the elastic component is a disc spring.

Preferably, the disc springs are arranged in pairs and in a face-to-face mode, and the inner diameters of the disc springs are in contact.

Preferably, the outer circle of the disc spring is respectively contacted with the bearing outer ring and the locking block which can be preloaded.

Preferably, the outer circle of the disc spring is respectively contacted with the pre-tightening bearing outer ring and the end cover bearing chamber.

Preferably, the pre-tensionable bearing is an angular contact bearing.

Compared with the prior art, the utility model has the advantages of it is following:

1) the axial play is greatly reduced.

Due to the structural problem of the deep groove ball bearing, the bearing clearance cannot be effectively eliminated, and usually, under the condition that the motor can normally work, the play amount of 0.1-0.2mm exists when 15kg of axial force is received.

After the bearing capable of being pre-tightened is used, the movement amount under the same condition is only 0.003-0.006 mm. The axial play can be greatly reduced, particularly in linear transmission, the motor can receive axial push-pull force all the time, and the use condition of high positioning precision and high precision is very significant after the play value is reduced.

2) The bearing is applied with pretightening force, and the proper pretightening force can increase the rigidity and the bearing capacity of the bearing, prolong the service life and the like.

Meanwhile, the performance of the whole machine can be optimized by adjusting the pretightening force according to different application environments and requirements. For example: the pretightening force can be properly increased for heavy load requirements; the pre-tightening force can be properly reduced for high-speed light load.

3) The axial load capacity is increased, and the service life of the motor is prolonged.

The bearing capacity of the deep groove ball bearing is mainly radial force and partial axial force. However, in the case of a linear drive, the motor body is constantly carrying alternating axial loads. Usually, for a motor, the bearing is usually damaged first.

The problem that a single angular contact bearing can only bear unidirectional force is solved by using the angular contact bearings in pairs, and the bearing capacity of the whole system to axial force is improved.

Drawings

FIG. 1 is a schematic sectional view of the present invention;

FIG. 2 is a schematic view of the overall structure of the present invention;

fig. 3 is a schematic front view of an explosive structure according to an embodiment of the present invention;

fig. 4 is a perspective view of an explosive structure according to an embodiment of the present invention;

FIG. 5 is a schematic structural view of a disc washer according to the present invention;

fig. 6 is a graph showing the positioning torque value and the axial displacement at 15kg according to the embodiment of the present invention.

Wherein 1 is a locking block, 2 is a bearing capable of being pre-tightened, 3 is an elastic component, and 4 is a rotor.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, not all, of the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts shall fall within the protection scope of the present invention.

As shown in fig. 1 and 2, a low axial float motor includes a front end cover, a rear end cover, a stator, a rotor 4 and a bearing, wherein the bearing is a pre-tightening bearing 2, two ends of the rotor 4 are fixed in bearing chambers of the front and rear end covers through a pair of pre-tightening bearings 2, and a mechanism for providing pre-tightening force is mounted on the pre-tightening bearing 2;

the pre-tightening force is adjusted according to different motor series, so that the motor positioning torque is at a set value. Preferably, the positioning torque value is controlled to be between 2% and 30% of the static torque when the motor is rated with current.

The mechanism for providing the pretightening force comprises a locking block 1 and an elastic component 3, wherein the elastic component 3 is arranged on a bearing 2 capable of being pretightened by the locking block 1. As shown in fig. 5, the elastic member 3 is a disc spring. The disc springs are arranged in pairs and in a face-to-face mode, and the inner diameters of the disc springs are in contact with each other.

The excircle of the disk spring is respectively contacted with the outer ring of the pre-tightening bearing 2 and the locking block 1. In another embodiment, the outer circle of the disc spring is respectively contacted with the outer ring of the pre-tightening bearing 2 and the end cover bearing chamber.

The pre-tightening bearing 2 is an angular contact bearing, axial play is greatly reduced after the pre-tightening bearing is used, particularly, in linear transmission, the motor can receive axial push-pull force all the time, and the reduction of the play value is very significant for the use conditions of high positioning precision and high precision.

DETAILED DESCRIPTION OF EMBODIMENT (S) OF INVENTION

As shown in fig. 3-4, taking the NEMA23 motor as an example: according to the size of the NEMA23 series motor, an angular contact bearing is selected, and the inner diameter and the outer diameter of the angular contact bearing are respectively phi 12mm and phi 28 mm. And (3) searching a disc-shaped gasket with a proper size according to the size of the conventional inner ring and the conventional outer ring of the bearing, so that the disc-shaped gasket acts on the outer ring of the bearing. The angular contact bearings are positioned at the front end and the rear end of the motor face to face, and the belleville springs are positioned in front of the angular contact bearings and the locking blocks at the front part of the motor back to back. The pre-tightening force is set to be 70-100mN · m. After the assembly is completed, the locking block is adjusted to a proper pretightening force, the bearing cannot reach an ideal pretightening state for the pretightening force smaller than the recommended value, and the motor output torque is reduced for the pretightening force larger than the recommended value, so that the motor is out of step. And finally, ensuring that the axial play value is in a control range by measuring the motor positioning torque value and the motor axial play value, as shown in fig. 6.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope of the present invention, and these modifications or replacements should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.

Claims (7)

1. A low axial float motor comprises a front end cover, a rear end cover, a stator, a rotor (4) and a bearing, and is characterized in that the bearing is a pre-tightening bearing (2), two ends of the rotor (4) are fixed in bearing chambers of the front end cover and the rear end cover through a pair of pre-tightening bearings (2), and a mechanism for providing pre-tightening force is arranged on the pre-tightening bearing (2).

2. The motor with low axial play as claimed in claim 1, wherein the mechanism for providing the pre-tightening force comprises a locking block (1) and an elastic component (3), the elastic component (3) is installed between the locking block (1) and the pre-tightening bearing (2), and the motor positioning torque is controlled by adjusting the magnitude of the pre-tightening force through adjusting the locking block (1).

3. A low axial play electric machine according to claim 2, wherein the resilient member (3) is a disc spring.

4. A low axial play electric motor as claimed in claim 3 wherein said belleville springs are arranged in pairs and face to face with their inner diameters touching.

5. A motor with low axial play as claimed in claim 3, wherein the outer circle of the belleville spring contacts the outer ring of the pre-tightened bearing (2) and the locking block (1) respectively.

6. A motor with low axial play as claimed in claim 3, wherein the outer circle of the belleville spring contacts the outer ring of the pre-tensionable bearing (2) and the end cap bearing chamber respectively.

7. A motor with low axial play according to claim 1, characterized in that the pre-loadable bearing (2) is an angular contact bearing.

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