CN118513834A - Automatic bearing preload mechanism - Google Patents

Abstract

The invention discloses an automatic bearing pre-tightening mechanism, comprising a housing, a slide assembly, a stop assembly, a differential assembly and a drive assembly, wherein the differential assembly comprises a high-speed gear and a low-speed gear, wherein the high-speed gear is driven by a locking nut, and the low-speed gear is driven by a mandrel, wherein the stop assembly comprises a torque disk, a pull rope and a weight, wherein the drive assembly drives the high-speed gear and the low-speed gear to rotate in the same direction at a differential speed, so that the locking nut is gradually tightened, and when the pre-tightening force is greater than or equal to a preset value, the outer ring of the bearing assembly begins to drive the clamping seat and the torque disk to rotate, and the weight is lifted by the pull rope, and after the weight is out of contact with the contact point, the drive assembly is powered off and stops rotating. The invention controls the friction torque of the pre-tightened bearing assembly through the stop assembly, and realizes pre-tightening by driving the locking nut and the mandrel to rotate in the same direction at a differential speed through a group of differential gears, thereby ensuring that the pre-tightening working condition is consistent with the actual working condition, and automatically stops pre-tightening when the pre-tightening force is greater than or equal to the preset value, and the pre-tightening force is precisely controlled and has a high degree of automation.

Description

Automatic bearing preload mechanism

Technical Field

The invention relates to the technical field of bearing preload, and in particular to an automatic bearing preload mechanism.

Background Art

The bearing assembly is an assembly including a bearing, a spindle, a bearing seat and a locking nut. The bearing type can be a tapered roller bearing, an angular contact bearing, a thrust bearing or other bearings with adjustable clearance. This type of bearing assembly generally uses tightening the locking nut to achieve pre-tightening.

When tightening the locking nut for pre-tightening, it is necessary to overcome the friction resistance of the thread itself and the friction between the matching surfaces of the bearing and the shaft or hole during the tightening process of the locking nut. Due to the existence of processing errors, when the same tightening torque is applied, the pre-tightening amount of the bearing varies greatly. Therefore, in order to ensure the consistency of pre-tightening, the friction torque of the bearing assembly after pre-tightening can be detected to enable the bearing to reach the specified clearance and obtain the expected stiffness.

However, in actual assembly operations, operators need to tighten the nuts multiple times and detect the bearing friction torque. Once the pre-tightening is excessive, the nuts need to be loosened and re-tightened. The operation process is relatively cumbersome, and during the pre-tightening process, the bearing rolling elements are in a stationary state, and the obtained test data is different from the actual working state.

Therefore, how to create a new automatic bearing preload mechanism is one of the important current research and development topics.

Summary of the invention

The technical problem to be solved by the present invention is to provide an automatic bearing preload mechanism, which can be used to preload the bearing when it is rotating to obtain a preload force consistent with the actual working conditions, and can automatically stop screwing the locking nut when the preload force is greater than or equal to a preset value to avoid excessive preload, thereby overcoming the shortcomings of the prior art.

In order to solve the above technical problems, the present invention provides an automatic bearing pre-tightening mechanism for pre-tightening a bearing assembly, wherein the bearing assembly comprises a spindle, a bearing, a bearing seat and a locking nut, wherein the spindle is installed in the bearing seat through a pair of bearings, the bearing seat serves as the outer ring of the bearing assembly, and the locking nut is screwed into the tail end of the spindle, and pre-tightening is achieved by tightening the locking nut;

The above-mentioned automatic bearing preload mechanism comprises a housing, a slide assembly, a stop assembly, a differential assembly and a drive assembly;

The box body is hollow, and the interior is used to provide installation space and support for the differential assembly and the drive assembly, and the slide assembly and the stop assembly are arranged outside the box body;

The slide assembly comprises a slide, a first bearing and a clamping seat, and the first bearing is horizontally mounted on the slide;

The stop assembly includes a torque disc, a pull rope and a weight, wherein the torque disc is connected to the clamp seat, the pull rope is wound around the outer circumference of the torque disc, one end of the pull rope is connected to the torque disc, and the other end is connected to the weight, a contact is arranged directly below the weight, and the weight and the contact are electrically connected to the drive assembly through cables respectively;

The differential assembly includes a high-speed gear and a low-speed gear, both of which are coaxially arranged with the bearing assembly, the high-speed gear is drivingly connected to the locking nut, the low-speed gear is drivingly connected to the spindle, and the speed of the high-speed gear is greater than that of the low-speed gear;

The bearing assembly passes through the center of the slide seat, and the clamp seat is tightly fixed on the outer ring of the bearing assembly. The driving assembly drives the high-speed gear and the low-speed gear to rotate in the same direction at a differential speed, so that the locking nut is gradually tightened. When the preload force is greater than or equal to the preset value, the outer ring of the bearing assembly begins to drive the clamp seat and the torque plate to rotate, and the weight is lifted by the pull rope. After the weight is out of contact with the contact, the driving assembly is powered off and stops.

As an improvement of the present invention, the slide assembly further includes an optical axis, a spring, a bushing and a limit spacer;

The optical axis is arranged horizontally, and a guide hole is provided on the slide seat for allowing the optical axis to pass through. The slide seat is slidably connected to the optical axis, and a baffle is provided at the end of the optical axis. A spring is mounted on the outside of the optical axis, one end of the spring is connected to the baffle, and the other end is connected to the side wall of the slide seat. The elastic force of the spring is used to push the slide seat to slide along the optical axis. A bushing is provided between the inner wall of the guide hole and the optical axis to reduce sliding friction. A limiting spacer is provided on the side wall of the slide seat facing the box body along the outer periphery of the guide hole for limiting and buffering.

Furthermore, the clamp seat is annular, with an axial length greater than the thickness of the slide seat, and an axial opening is provided at the upper end of the clamp seat extending outside the slide seat. The opening is connected by bolts, and tightening the bolts is used to make the clamp seat clamp the bearing assembly to achieve fixation.

Furthermore, the stop assembly also includes a weight support frame and a weight limit frame. The weight support frame is connected to the sliding seat by bolts and is used to place the weight and set contacts. The weight limit frame is connected to the weight support frame by bolts and is located above the weight to limit the stroke of the weight.

Furthermore, the differential assembly also includes a bearing fixing seat, a second bearing, an outer turntable, a third bearing and a core shaft sleeve. An inner bracket is arranged in the housing, the bearing fixing seat is horizontally installed on the inner bracket, the bearing fixing seat is annular, the outer turntable is rotatably connected to the outer periphery of the bearing fixing seat through the second bearing, the core shaft sleeve is rotatably connected to the inner periphery of the bearing fixing seat through two third bearings, the high-speed gear is connected and fixed to the outer turntable by bolts, and the low-speed gear is connected and fixed to the core shaft sleeve by bolts.

Furthermore, the high-speed gear and the locking nut are connected by a keyway, and the mandrel sleeve and the mandrel are connected by a keyway.

Furthermore, a horizontal mounting hole is opened on the inner bracket, and the bearing fixing seat is placed in the hole. An opening is opened axially at the upper end of the inner bracket, and the opening is connected by bolts. Tightening the bolts is used to make the inner bracket hug the bearing fixing seat to achieve installation and fixation of the bearing fixing seat.

Furthermore, the driving assembly includes a motor and a driving gear shaft, the motor is installed outside the right side wall of the box, the driving shaft of the motor extends into the box, the driving gear shaft and the output shaft of the motor are coaxially transmitted, and are horizontally installed between the left and right side walls of the box through two fourth bearings, and the driving gear shaft is provided with a first driving gear and a second driving gear, the first driving gear is meshed with the high-speed gear, and the second driving gear is meshed with the low-speed gear.

After adopting such a design, the present invention has at least the following advantages:

1. In the differential assembly, the high-speed gear is driven by the lock nut, and the low-speed gear is driven by the mandrel sleeve and the mandrel. The speed difference between the high-speed gear and the low-speed gear is used to gradually tighten the lock nut, so as to achieve pre-tightening when the bearing is rotating, thereby obtaining a pre-tightening force consistent with the actual working conditions, ensuring the assembly quality of the bearing assembly;

2. The slide assembly is guided by the optical axis and pushes the bearing assembly to the working position through the elastic force of the spring. It is not only easy to operate, but also can effectively ensure the consistency of the position of the bearing assembly and avoid axial displacement during the preload process.

3. The stop assembly provides the initial resistance torque for the bearing assembly through the torque disk, the pull rope and the weight to ensure that the outer ring of the bearing assembly is stationary during the pre-tightening process. When the pre-tightening force of the bearing assembly is greater than or equal to the preset value, the friction torque of the bearing assembly is greater than the sum of the resistance torque and the friction torque of the first bearing. At this time, the outer ring of the bearing assembly starts to rotate, and then pulls the weight, so that the weight is lifted and separated from the contact, and the motor is powered off and stopped; the torque is provided by the weight's own gravity, the structure is simple, accurate and reliable, the cost is low, and the pre-tightening process is highly automated, which effectively solves the cumbersome procedure of measuring while pre-tightening during manual pre-tightening;

4. The preload force preset value can be adjusted by adjusting the weight of the weight or adding a spring to the bottom of the weight. It can also be measured in real time by adding a torque sensor, which makes the adjustment convenient and flexible.

BRIEF DESCRIPTION OF THE DRAWINGS

The above is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention, the present invention is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

FIG. 1 is a schematic structural diagram of a bearing assembly.

FIG. 2 is a schematic diagram of the three-dimensional structure of an automatic bearing preload mechanism provided by the present invention.

FIG. 3 is a schematic diagram of the three-dimensional structure of an automatic bearing preload mechanism provided by the present invention from another angle.

FIG. 4 is a schematic diagram of a top cross-sectional structure of an automatic bearing preload mechanism provided by the present invention.

FIG. 5 is a partial enlarged schematic diagram of point A in FIG. 4 .

FIG. 6 is a side structural schematic diagram of an automatic bearing preload mechanism provided by the present invention.

Explanation of the reference numerals in the accompanying drawings: 1. bearing assembly; 11. bearing; 12. spindle; 13. locking nut; 14. bearing seat; 2. slide assembly; 21. slide; 22. clamp seat; 23. first bearing; 24. optical axis; 25. spring; 26. bushing; 27. limit ring; 3. stop assembly; 31. torque plate; 32. pull rope; 33. weight; 34. weight support frame; 35. weight limit frame; 36. cable; 4. differential assembly; 41. high-speed gear; 42. low-speed gear; 43. bearing fixing seat; 44. outer turntable; 45. second bearing; 46. spindle sleeve; 47. third bearing; 5. drive assembly; 51. motor; 52. driving gear shaft; 53. first driving gear; 54. second driving gear; 55. fourth bearing; 6. housing; 61. inner bracket.

DETAILED DESCRIPTION

Please refer to Figure 1, which shows a bearing assembly 1, which is a preloaded part in the present invention. The bearing assembly 1 includes a bearing 11, a spindle 12, a locking nut 13 and a bearing seat 14. The spindle 12 is installed in the bearing seat 14 through a pair of bearings 11. The bearing seat 14 serves as the outer ring of the bearing assembly 1. The locking nut 13 is screwed into the rear end of the spindle 12. In the initial state, the bearing assembly 1 has a large clearance. The clearance can be adjusted to a specified value by tightening the locking nut 13, thereby achieving preload. It should be noted that in Figure 1, the bearing 11 adopts a tapered roller bearing, and Figures 2 to 5 are all described by taking the bearing assembly as an example. In actual assembly, the bearing 11 in the bearing assembly 1 can also be an angular contact bearing or a thrust bearing or other types of bearings with adjustable clearance.

Please refer to Figures 2 to 5. The present invention provides an automatic bearing preload mechanism for preload a bearing assembly 1, including a slide assembly 2, a stop assembly 3, a differential assembly 4, a drive assembly 5, a stop assembly 5 and a housing 6.

The box body 6 is hollow, and the interior is used to provide installation space and support for the differential assembly 4 and the drive assembly 5. The slide assembly 2 and the stop assembly 3 are arranged outside the box body 6. In this embodiment, an inner bracket 61 is also provided inside the box body 6, and the inner bracket 61 is used to provide support for the differential assembly 4.

The slide assembly 2 includes a slide 21 , a clamping seat 22 , a first bearing 23 , an optical axis 24 , a spring 25 , a bushing 26 and a limit ring 27 .

The slide seat 21 is vertically arranged, with a bearing mounting hole in the center and guide holes in the upper and lower parts.

The clamp seat 22 is annular and is horizontally mounted on the slide seat 21 through the first bearing. The axial length of the clamp seat 22 is greater than the thickness of the slide seat 21, so a portion of the clamp seat 22 (the left end in FIG. 4 ) protrudes out of the slide seat 21 after installation, and an axial opening is formed at the upper end of the portion of the clamp seat 22 protruding out of the slide seat 21, and the opening is connected by bolts. Tightening the bolts can make the clamp seat 22 hold the outer ring of the bearing assembly 1 tightly.

The optical axis 24 is horizontally arranged and passes through the guide hole on the slide 21. The slide 21 is slidably connected between the optical axis 24. A baffle is arranged at the left end of the optical axis.

The spring 25 is sleeved on the outside of the optical axis 24 , one end of the spring 25 is connected to the baffle, and the other end of the spring 25 is connected to the side wall of the slide seat 21 .

A bushing 26 is provided between the inner wall of the guide hole and the optical axis, and the bushing 26 serves to reduce sliding friction.

A limiting spacer 27 is provided on the side wall of the sliding seat 21 facing the box body 6 along the outer periphery of the guide hole. The limiting spacer 27 can adjust the thickness according to actual conditions to play a role of limiting and buffering.

The stop assembly 3 includes a torque plate 31 , a pull rope 32 , a weight 33 , a weight support frame 34 and a weight limiting frame 35 .

The torque disc 31 is coaxially arranged with the clamp seat 22 and fixed by bolt connection. The pull rope 32 is wound around the outer periphery of the torque disc 31, one end of the pull rope 32 is connected to the torque disc 31, and the other end is connected to the weight 33. The weight support frame 34 is connected to the slide seat 21 by bolts, the weight 33 is placed on the weight support frame 34, and a contact is provided directly below the weight 33, the weight 33 is pressed on the contact by its own gravity, and the weight 33 and the contact are electrically connected to the drive assembly 5 by cables 36 respectively. In this embodiment, a weight limit frame 35 is also provided above the weight 33, and the weight limit frame 35 is connected and fixed to the weight support frame 34 by bolts, and is used to limit the stroke of the weight 33.

The differential assembly 4 includes a high-speed gear 41 , a low-speed gear 42 , a bearing fixing seat 43 , a second bearing 44 , an outer rotating plate 45 , a third bearing 46 and a core sleeve 47 .

The bearing fixing seat 43 is annular and horizontally mounted on the inner bracket 61. In this embodiment, a horizontal mounting hole is opened on the inner bracket 61, and the bearing fixing seat 43 is placed in the hole. An opening is opened in the axial direction at the upper end of the inner bracket 61, and the opening is connected by bolts. Tightening the bolts can make the inner bracket 61 hold the bearing fixing seat 43 tightly, so as to achieve the installation and fixation of the bearing fixing seat 43.

The outer turntable 45 is rotatably connected to the outer periphery of the bearing fixing seat 43 through the second bearing 44, the core shaft sleeve 47 is rotatably connected to the inner periphery of the bearing fixing seat 43 through two third bearings 46, the high-speed gear 41 is connected and fixed to the outer turntable 45 by bolts, and the low-speed gear 42 is connected and fixed to the core shaft sleeve by bolts.

The high-speed gear 41, the low-speed gear 42, the bearing fixing seat 43, the outer rotating disk 45 and the mandrel sleeve 47 are all coaxial with the bearing assembly 1. The high-speed gear 41 and the locking nut 13 are provided with keys and grooves that match each other, and the mandrel sleeve 47 and the mandrel 12 are provided with keys and grooves that match each other. When the bearing assembly 1 is in the working position, a keyway connection is formed between the high-speed gear 41 and the locking nut 13, and a keyway connection is formed between the mandrel sleeve 47 and the mandrel 12. The speed of the high-speed gear 41 is greater than that of the low-speed gear 42, so that the locking nut 13 can be gradually tightened, thereby realizing the pre-tightening of the bearing assembly 1.

The driving assembly 5 includes a motor 51 , a driving gear shaft 52 , a first driving gear 53 , a second driving gear 54 and a fourth bearing 55 .

The motor 51 is installed outside the right side wall of the box body 6, and the driving shaft of the motor 51 extends into the box body 6. The driving gear shaft 52 is coaxially driven with the output shaft of the motor 51, and is horizontally installed between the left and right side walls of the box body 6 through two fourth bearings 55. The driving gear shaft 52 is provided with a first driving gear 53 and a second driving gear 54, the first driving gear 53 is meshed with the high-speed gear 41, and the second driving gear 54 is meshed with the low-speed gear 42.

The workflow of the present invention is as follows:

First, manually push the slide 21 to the left for a distance, and pass the bearing assembly 1 through the clamp seat 22 from right to left. The right end of the outer ring of the bearing assembly 1 has a flange. Push the bearing assembly 1 until the side wall of the slide 21 is against the flange. At this time, tighten the bolts on the upper end of the clamp seat 22 so that the clamp seat 22 holds and fixes the outer ring of the bearing assembly 1, thereby completing the fixation of the bearing assembly 1.

Then manually turn the high-speed gear 41 to align the key and groove on the core shaft 12 with the core shaft sleeve 47, and at the same time align the locking nut 13 with the key and groove on the high-speed gear 41, and use the elastic force of the spring 25 to push the slide 21 to slide rightward along the optical axis 24, thereby pushing the bearing assembly 1 to the working position.

Then, the power of the motor 51 is turned on, and the motor 51 drives the first driving gear 53 and the second driving gear 54 to rotate synchronously. Since the transmission ratios of the two gear pairs are different, the rotation speed of the high-speed gear 41 is slightly greater than that of the low-speed gear 42.

At the beginning of pre-tightening, the bearing assembly 1 has a large clearance, the outer ring is in a stationary state, and the locking nut rotates at a speed slightly higher than the spindle 12, thereby gradually tightening.

During the pre-tightening process, the clearance of the bearing assembly 1 gradually decreases and the friction torque gradually increases.

When the preload force is greater than or equal to the preset value, the friction torque of the bearing assembly 1 is greater than the sum of the torque applied to the torque plate 31 by the gravity of the weight 33 and the friction torque of the first bearing 23 itself. At this time, the outer ring of the bearing assembly 1 starts to rotate, and the torque plate 31 rotates accordingly and lifts the weight 33. After the weight 33 disengages from the contact, the motor 51 is powered off and stops, completing the preload.

The present invention controls the friction torque of the preloaded bearing assembly through a stop assembly, and realizes preloading by driving the locking nut and the core shaft to rotate differentially in the same direction through a set of differential gears, thereby ensuring that the preloading condition is consistent with the actual condition, and automatically stops preloading when the preloading force is greater than or equal to a preset value. The preloading force is accurately controlled and the degree of automation is high.

The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Those skilled in the art may make some simple modifications, equivalent changes or modifications using the technical contents disclosed above, which are all within the protection scope of the present invention.

Claims (8)

1. The automatic bearing pre-tightening mechanism is used for pre-tightening a bearing assembly, the bearing assembly comprises a mandrel, a bearing seat and a locking nut, the mandrel is arranged in the bearing seat through a pair of bearings, the bearing seat is used as an outer ring of the bearing assembly, the locking nut is screwed into the tail end of the mandrel, and pre-tightening is realized by screwing the locking nut, and the automatic bearing pre-tightening mechanism is characterized by comprising a box body, a sliding seat assembly, a stop assembly, a differential assembly and a driving assembly;

the box body is hollow, the inside of the box body is used for providing installation space and support for the differential assembly and the driving assembly, and the sliding seat assembly and the stop assembly are arranged outside the box body;

The slide seat assembly comprises a slide seat, a first bearing and a clamping seat, and the clamping seat is horizontally arranged on the slide seat through the first bearing;

The stop assembly comprises a moment disc, a pull rope and a heavy hammer, wherein the moment disc is connected with the clamping seat, the pull rope is wound around the periphery of the moment disc, one end of the pull rope is connected with the moment disc, the other end of the pull rope is connected with the heavy hammer, a contact is arranged right below the heavy hammer, and the heavy hammer and the contact are respectively and electrically connected with the driving assembly through a cable;

The differential assembly comprises a high-speed gear and a low-speed gear, the high-speed gear and the low-speed gear are both coaxially arranged with the bearing assembly, the high-speed gear is in transmission connection with the lock nut, the low-speed gear is in transmission connection with the mandrel, and the rotating speed of the high-speed gear is greater than that of the low-speed gear;

the bearing assembly penetrates through the center of the sliding seat, the clamping seat is fixedly clamped outside the outer ring of the bearing assembly, the driving assembly drives the high-speed gear and the low-speed gear to rotate in the same direction in a differential mode, the locking nut is screwed gradually, when the pretightening force is larger than or equal to a preset value, the outer ring of the bearing assembly starts to drive the clamping seat and the moment disc to rotate, the heavy hammer is lifted through the pull rope, and after the heavy hammer is separated from contact with the contact, the driving assembly is powered off and stops rotating.

2. The automatic bearing pre-tightening mechanism according to claim 1, wherein the slide assembly further comprises an optical axis, a spring, a bushing, and a spacing spacer;

The optical axis level sets up, opens on the slide and has the guiding hole that allows the optical axis to pass, sliding connection between slide and the optical axis, and the tip of optical axis is provided with the baffle, and the outside cover of optical axis is equipped with the spring, and the one end and the baffle of spring are connected, and the other end and slide lateral wall are connected, the elasticity of spring is used for promoting the slide and slides along the optical axis, is equipped with the bush between guiding hole inner wall and the optical axis for reduce sliding friction, be equipped with spacing spacer along guiding hole periphery on the slide lateral wall of one side towards the box, be used for spacing and buffering.

3. The automatic bearing pre-tightening mechanism according to claim 1, wherein the clamping seat is annular, the axial length of the clamping seat is larger than the thickness of the sliding seat, an axial opening is formed in the upper end of the part, extending out of the sliding seat, of the clamping seat, the opening is connected through a bolt, and the clamping seat is tightly held by the bearing assembly through screwing the bolt so as to achieve fixation.

4. The automatic bearing pre-tightening mechanism according to claim 1, wherein the stop assembly further comprises a weight support and a weight limiting frame, the weight support is connected with the slide seat through a bolt for placing the weight and setting the contact, and the weight limiting frame is connected with the weight support through a bolt and is located above the weight for limiting the travel of the weight.

5. The automatic bearing pre-tightening mechanism according to claim 1, wherein the differential assembly further comprises a bearing fixing seat, a second bearing, an outer rotary disc, a third bearing and a mandrel sleeve, an inner support is arranged in the box body, the bearing fixing seat is horizontally arranged on the inner support, the bearing fixing seat is annular, the outer rotary disc is rotatably connected to the periphery of the bearing fixing seat through the second bearing, the mandrel sleeve is rotatably connected to the inner periphery of the bearing fixing seat through the two third bearings, the high-speed gear is fixedly connected with the outer rotary disc through bolts, and the low-speed gear is fixedly connected with the mandrel sleeve through bolts.

6. The automatic bearing pre-tightening mechanism according to claim 5, wherein the high-speed gear is in key-slot connection with the lock nut, and the core sleeve is in key-slot connection with the core shaft.

7. The automatic bearing pre-tightening mechanism according to claim 5, wherein the inner bracket is provided with a horizontal mounting hole, the bearing fixing seat is arranged in the hole, the upper end of the inner bracket is provided with an opening along the axial direction, the opening is connected through a bolt, and the bolt is screwed for enabling the inner bracket to clamp the bearing fixing seat so as to realize the mounting and fixing of the bearing fixing seat.

8. The automatic bearing pre-tightening mechanism according to claim 1, wherein the driving assembly comprises a motor and a driving gear shaft, the motor is arranged outside the right side wall of the box body, a driving shaft of the motor stretches into the box body, the driving gear shaft and an output shaft of the motor are coaxially transmitted and horizontally arranged between the left side wall and the right side wall of the box body through two fourth bearings, a first driving gear and a second driving gear are arranged on the driving gear shaft, the first driving gear is meshed with the high-speed gear, and the second driving gear is meshed with the low-speed gear.