Hollow shaft motor test loading mechanism

Abstract

The invention discloses a hollow shaft motor test loading mechanism, which comprises an extension shaft fixedly butted with the outer end of a motor shaft and a torque device for applying downward pressure to the motor shaft through the extension shaft, and is characterized in that the front end and the rear end of the extension shaft are respectively provided with a supporting stress point and a pressing stress point; the torque device provides upward supporting force F0 and downward pressing force F1 for the supporting force bearing point and the pressing force bearing point respectively, and the magnitude of the supporting force F0 and the magnitude of the pressing force F1 and the proportion of the supporting force F0 and the pressing force F1 are adjusted, so that the motor shaft bears loads exceeding the minimum load in the front end bearing and the rear end bearing in the motor. The device has the advantages that loads of the front end bearing and the rear end bearing are increased in a balanced manner, so that the rolling units can rotate along with rotation of the motor shaft, friction between the rolling units and the inner ring and the outer ring is rolling friction, sliding friction is avoided, and it is guaranteed that the front end bearing and the rear end bearing are not damaged in the test process of the hollow shaft motor; the structure is simple and reasonable, and operation is very easy.

Description

Technical Field

[0001] The invention relates to a hollow shaft motor test loading mechanism, belonging to the technical field of motor test fixtures. Background Art

[0002] The minimum bearing load is the minimum load that the bearing must bear in order to ensure the normal operation of the bearing and protect the bearing from damage. This minimum load is crucial to the normal operation of the bearing because it ensures that the rolling elements inside the bearing can obtain the necessary support and lubrication during the rotation process, so that all rolling elements can roll evenly, thereby avoiding the wear caused by long-term unlubricated friction in the local position of some rolling elements, and maintaining the performance and life of the bearing.

[0003] The mechanism of bearing damage when the bearing is below the minimum load is: due to the inherent friction resistance between the axially arranged rolling elements and the cage and between the inner and outer rings, when the force applied by the shaft to the inner ring is too small, the force applied by the inner ring to the rolling element (ball or cylinder) is also very small, and the friction resistance formed between the inner ring and the rolling element will not be enough to overcome the inherent friction resistance of the rolling element, so the rotating inner ring cannot drive the rolling element to roll together. Therefore, a high-speed relative friction motion is formed between the high-speed rotating inner ring and the contacting rolling element, which significantly increases the rapid wear of the contact part between the inner ring and the rolling element. Furthermore, since there is a set oil film gap between the inner ring and the rolling element, when the inner ring is in relative friction with the rolling element on one side, all the rolling elements on the other side do not have contact friction with the inner ring, and since the friction-affected rolling element does not roll in the groove of the outer ring, this causes the following situations: 1. Since the rolling elements that are subject to friction do not roll in the groove of the outer ring, the friction parts with the inner ring cannot obtain new lubricating oil, which not only aggravates the wear of the friction parts of the rolling elements, but also aggravates the wear of the inner ring; 2. Since the rolling element subjected to friction does not roll in the groove of the outer ring, only the fixed part of the rolling element subjected to friction is worn, its circumference is damaged, and the rolling performance is lost.

[0004] The motor shaft of a hollow shaft motor has a front end bearing and a rear end bearing inside the motor. When the manufacturer conducts an idling test, the motor shaft does not have any load. Originally, the motor shaft can basically meet the minimum load requirement by using its own weight and the weight of the assembled rotor. However, in recent years, with the promotion of lightweight requirements, the motor shaft has been hollowed, which has reduced the weight of the originally heavy motor shaft by about half. During the idling test, the load on the front end bearing and the rear end bearing of the motor shaft inside the motor begins to be lower than the minimum load. If this problem is not solved, the bearing damage as described above will inevitably occur in the idling test. Summary of the invention

[0005] The technical problem to be solved by the present invention is: how to solve the problem that the front end bearing and the rear end bearing built into the motor shaft of the hollow shaft motor cannot meet the minimum load when performing an idling test.

[0006] In view of the above problems, the technical solution proposed by the present invention is: A hollow shaft motor test loading mechanism comprises an extension shaft fixedly docked with the outer end of the motor shaft, and a torque device for applying downward pressure to the motor shaft through the extension shaft, a support force point and a downward pressure force point are respectively arranged at the front end and the rear end of the extension shaft, and the torque device provides an upward support force F0 and a downward pressure F1 to the support force point and the downward pressure point respectively, and the magnitude of the support force F0 and the downward pressure F1 and the ratio therebetween are adjusted so that the front end bearing and the rear end bearing of the motor shaft in the motor are both subjected to a load exceeding the minimum load.

[0007] A supporting bearing and a downward pressure bearing are respectively provided at the supporting force point and the downward pressure force point of the extension shaft, and the supporting force F0 and the downward pressure F1 applied by the torque device to the supporting force point and the downward pressure point act on the supporting bearing and the downward pressure bearing respectively.

[0008] The torque device is arranged below the extension shaft, and includes a support and a lever. The lever is parallel to the extension shaft. The front section of the lever is a support arm, and the rear section is a downward pressure arm. A support component capable of acting upward on the bottom of the support bearing is provided at the front end of the support arm, and a downward pressure component capable of acting downward on the top of the downward pressure bearing is provided at the rear end of the downward pressure arm. The support component can slide forward or backward on the support arm.

[0009] The support assembly and the pressing assembly both have elastic members, and the support assembly applies a supporting force F0 to the support bearing through the elastic member, and the pressing bearing applies a pressing force F1 to the pressing bearing through the elastic member.

[0010] The elastic member is a compression spring.

[0011] The support assembly also includes an upper seat body and a lower seat body, the upper seat body is used to support the bottom of the support bearing, the lower seat body is pressed on the support arm, and the compression spring is located between the upper seat body and the lower seat body; the lower seat body is provided with a downward opening slide groove, the slide groove is sleeved on the support arm and can slide back and forth on the support arm.

[0012] The pressing assembly also includes an upper seat body 2 and a pull-down member, the upper seat body 2 is pressed on the upper part of the pressing bearing, the pull-down member includes an inverted U-shaped pull-down frame opening downward and a hanging column crossing the rear end of the pressing arm, the pull-down frame includes a top plate, a pull-down plate 1 and a pull-down plate 2 suspended and fixed at both ends of the top plate, the lower ends of the pull-down plate 1 and the pull-down plate 2 are respectively provided with hanging holes, when used, the pull-down frame straddles the extension shaft, and the hanging holes at the lower ends of the pull-down plate 1 and the pull-down plate 2 are respectively sleeved on the two ends of the hanging column, the upper seat body 2 and the pressing bearing are located in the pull-down frame, and the extension spring is pressed between the top plate and the upper seat body 2.

[0013] It also includes a loading hanger and a counterweight block, wherein the loading hanger is hung at the rear end of the lower pressure arm, and the counterweight block is placed on the loading hanger.

[0014] The loading hanger has a hanging rod, the lower end of the hanging rod has a bottom supporting plate, and the counterweight block is placed on the bottom supporting plate.

[0015] The mounting position of the support bearing on the extension shaft can be shifted as the position of the support assembly on the lever changes. Beneficial Effects

[0016] 1. The loads of the front and rear bearings are evenly increased, so that the rolling unit can rotate with the rotation of the motor shaft. The friction between the rolling unit and the inner and outer rings is rolling friction, which avoids the occurrence of sliding friction and ensures that the front and rear bearings are not damaged during the hollow shaft motor test; 2. The structure is simple and reasonable, very easy to operate; 3. Suitable for testing motors of different specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a three-dimensional schematic diagram of the loading mechanism when in use; Figure 2 is a three-dimensional schematic diagram of the extension shaft; Figure 3 A three-dimensional schematic diagram of adding a loading pendant to the torque device; Figure 4 is a three-dimensional schematic diagram of the support assembly; Figure 5 is a three-dimensional schematic diagram of the pressing component; Figure 6 is a three-dimensional schematic diagram of the loading pendant; Figure 7 is a cross-sectional schematic diagram of the hollow shaft motor; Figure 8 A cross-sectional schematic diagram of the hollow shaft motor fixedly docking with the extension shaft; Fig. 9 A test diagram for obtaining the actual qualified support force F0 and down force F1; In the figure: 100, motor; 110, rotor; 1, support; 101, horizontal support shaft; 2, lever; 201, support arm; 202, lower pressure arm; 3, support assembly; 301, upper seat body 1; 3011, arc groove 1; 302, lower seat body; 3021, slide groove; 4, lower pressure assembly; 401, upper seat body 2; 4011, arc groove 2; 402, pull-down frame; 4021, top plate; 4022, Pull-down plate one; 4023, pull-down plate two; 4020, hanging hole; 5, loading hanger; 501, hanging rod; 502, bottom support plate; 6, hanging column; 7, compression spring; 8, counterweight; 9, whole shaft; 901, motor shaft; 902, extension shaft; 10, front end bearing; 11, rear end bearing; 12, support bearing; 13, downward pressure bearing; 14, support frame; 15, pressure sensor one; 16, pressure sensor two. DETAILED DESCRIPTION

[0018] like Figure 7 As shown, the motor 100 involved in the present application is generally a medium-to-large motor, and the portion of the motor shaft 901 outside the motor 100 is shorter, and the outer end portion thereof has a variety of connection structures for connecting with other machine axles such as flanges, external splines, end teeth, etc. The present application involves a motor shaft 901 whose outer end face has end teeth and an axially arranged threaded connection hole.

[0019] Figure 7 The figure shows a simplified cross-sectional view of the hollow shaft motor involved in the present application. The motor shaft 901 has a front end bearing 10 and a rear end bearing 11 in the motor 100 , and a rotor 110 mounted on the motor shaft 901 is between the front end bearing 10 and the rear end bearing 11 .

[0020] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1

[0021] like Figure 1 , 7As shown in , 8, a hollow shaft motor test loading mechanism includes an extension shaft 902 fixedly docked with the outer end of a motor shaft 901, and a torque device for applying downward pressure to the motor shaft 901 through the extension shaft 902. A support force point and a downward pressure force point are respectively set at the front end and the rear end of the extension shaft 902. The torque device provides an upward support force F0 and a downward pressure F1 to the support force point and the downward pressure point respectively. The magnitude of the support force F0 and the downward pressure F1 and the ratio between the two are adjusted so that the front end bearing 10 and the rear end bearing 11 of the motor shaft 901 in the motor 100 are subjected to a load exceeding the minimum load. Since the length of the motor shaft 901 outside the motor 100 is short, the motor shaft needs to be rigidly extended, so the extension shaft 902 is fixedly docked at the outer end of the motor shaft 901, so that the motor shaft 901 and the extension shaft 902 become a rigid whole shaft 9. It can be known from the lever principle that the present invention applies an upward supporting force F0 at the front end of the extension shaft 902, which actually makes the front end of the entire shaft 9 a fulcrum, and the entire shaft 9 becomes an arm that can rotate around the fulcrum. When we apply a downward downward pressure F1 at the rear end of the extension shaft 902, the motor shaft 901 at the rear end of the entire shaft 9 obtains a downward rotating force, so that the front end bearing 10 and the rear end bearing 11 of the motor shaft 901 in the motor 100 can obtain downward pressures F01 and F02 respectively. Obviously, whether the magnitude of the pressures F01 and F02 can meet the requirements of loading depends on the magnitude of the supporting force F0 and the downward pressure F1 and the ratio between the two. In particular, when the pressures F01 and F02 obtained by the test are equal or close, it is more necessary for the magnitude of the supporting force F0 and the downward pressure F1 to have a suitable ratio. If the supporting force F0 is too large, the load on the front end bearing 10 will be reduced, and the weight originally borne by the front end bearing 10 will be transferred to the front end and rear end bearings 11 of the extension shaft 902; if the supporting force F0 is too small, the downward pressure F1 applied to the rear end of the extension shaft 902 will cause the rear end of the motor shaft 901 to tilt up, and the load on the rear end bearing 11 will be reduced.

[0022] In order to meet the above requirements for the size of the support force F0 and the downward force F1 and the requirement of having a suitable ratio, the present application provides a simplest method, as described in the second embodiment and the attached Fig. 9 In this way, we use this mechanism to evenly increase the load of the front bearing 10 and the rear bearing 11 on the motor shaft 901 outside the motor 100 in the form of increasing torque, so that the rolling unit can rotate with the rotation of the motor shaft 901, and the friction between the rolling unit and the inner ring and the outer ring is rolling friction, avoiding the occurrence of sliding friction, ensuring that the front bearing 10 and the rear bearing 11 are not damaged during the hollow shaft motor test.

[0023] like Figure 1 , 2As shown, a support bearing 12 and a downward pressure bearing 13 are respectively provided at the support force point and the downward pressure force point of the extension shaft 902, and the support force F0 applied by the torque device to the support force point and the downward pressure F1 applied to the downward pressure force point act on the support bearing 12 and the downward pressure bearing 13. In this way, when a force is applied to the extension shaft 902, it will not affect the high-speed rotation of the extension shaft 902 following the motor shaft 901.

[0024] like Figure 1 , 3 As shown, the torque device is arranged below the extension shaft 902, and includes a support 1 and a lever 2. Preferably, a horizontal support shaft 101 is arranged on the support, and the lever 2 is mounted on the horizontal support shaft 101 and rotates with the horizontal support shaft 101 as a fulcrum. The lever 2 is parallel to the extension shaft 902, the front section of the lever 2 is a support arm 201, and the rear section is a lower pressure arm 202. A support assembly 3 capable of acting upward on the bottom of the support bearing 12 is arranged at the front end of the support arm 201, and a lower pressure assembly 4 capable of acting downward on the top of the lower pressure bearing is arranged at the rear end of the lower pressure arm 202. The support assembly 3 can slide forward or backward on the support arm 201. In this way, by applying a force to the extension shaft 902 through the lever 2 and the support assembly 3 and the downward pressure assembly 4, the support force F0 can be provided simultaneously while the downward pressure F1 is applied, and the effective length of the support arm 201 is actually changed by the support assembly 3 sliding forward or backward on the support arm 201, that is, the torque ratio of the support force F0 multiplied by the effective length of the support arm 201 to the downward pressure F1 multiplied by the length of the downward pressure arm 202 is changed, thereby making it easy to adjust the size ratio of the support force F0 and the downward pressure F1.

[0025] It should be noted that the mounting position of the support bearing 12 on the extension shaft 902 can be shifted as the position of the support assembly 3 on the lever 2 changes. Of course, the mounting position of the support bearing 12 on the extension shaft 902 is preferably the accurate mounting position obtained after a prior pre-test.

[0026] like Figure 1 , 3 As shown in Figures 4 and 5, the support component 3 and the downward pressure component 4 both have elastic parts. The support component 3 applies a supporting force F0 to the support bearing 12 through the elastic part, and the downward pressure bearing applies a downward force F1 to the downward pressure bearing through the elastic part. Since it is difficult to accurately set the height of the support 1 in the torque device, if the elastic part is not set, only one of the support component 3 and the downward pressure component 4 will contact the extension shaft 902, and the other component will not be able to contact the extension shaft 902, and thus will not be able to apply a force. Therefore, the setting of the extension component can automatically adjust the force relationship of all relevant force-bearing components including the support component 3, the downward pressure component 4, the front end bearing 10, and the rear end bearing 11.

[0027] Preferably, the elastic member is a compression spring 7 with a long compression stroke and easy to set the compression stroke, but it can also be a rubber body.

[0028] like Figure 1 , 4 The support assembly 3 further comprises an upper seat body 301 and a lower seat body 302. The upper seat body 301 is used to support the bottom of the support bearing 12. The lower seat body 302 is pressed on the support arm 201. The compression spring 7 is located between the upper seat body 301 and the lower seat body 302. The lower seat body 302 is provided with a downwardly opening slide groove 3021, which is sleeved on the support arm 201 and can slide forward and backward on the support arm 201. In order to facilitate stable contact with the support bearing 12, the upper seat body 301 is provided with an arc groove 3011 with an upward opening and a curvature consistent with the curvature of the outer ring of the support bearing 12.

[0029] like Figure 1 , 5 The pressing assembly 4 also includes an upper seat body 401 and a pull-down member, the upper seat body 401 is pressed on the upper part of the pressing bearing 13, the pull-down member includes an inverted U-shaped pull-down frame 402 with an opening downward and a hanging column 6 that crosses the rear end of the pressing arm 202, the pull-down frame 402 includes a top plate 4021, a pull-down plate 1 4022 and a pull-down plate 2 4023 suspended and fixed at both ends of the top plate 4021, the lower ends of the pull-down plate 1 4022 and the pull-down plate 2 4023 are respectively provided with hanging holes 4020, when used, the pull-down frame 402 straddles the extension shaft 902, the hanging holes 4020 at the lower ends of the pull-down plate 1 4022 and the pull-down plate 2 4023 are respectively sleeved on the two ends of the hanging column 6, the upper seat body 401 and the pressure bearing are located in the pull-down frame 402, and the extension spring 7 is pressed between the top plate 4021 and the upper seat body 2. In this way, the pressing arm 202 exerts a downward force on the pull-down frame 402, and can exert a downward force on the pressing bearing 13 through the compression spring 7 and the second upper seat body 401. In order to facilitate stable contact with the pressing bearing 13, the second upper seat body 401 is provided with an arc groove 4011 with an opening facing downward and the same arc as the outer ring of the pressing bearing 13.

[0030] like Figure 1 , 6 As shown, it also includes a loading hanger 5 and a counterweight 8, the loading hanger 5 is suspended at the rear end of the lower pressing arm 202, and the counterweight 8 is placed on the loading hanger 5. There can be multiple counterweights 8, and they also have different weights.

[0031] The loading hanger 5 has a hanging rod 501 , and a bottom supporting plate 502 is provided at the lower end of the hanging rod. The counterweight 8 is placed on the bottom supporting plate 502 . Embodiment 2

[0032] like Fig. 9As shown, a method for obtaining the size of the qualified supporting force F0 and the downward force F1 of the loading mechanism in the first embodiment and the appropriate ratio therebetween includes installation and testing.

[0033] Installation: Complete the assembly of the front-end bearing 10, the rear-end bearing 11 and the rotor 110 or substitute parts on the motor shaft 901; complete the fixed docking of the extension shaft 902 on the motor shaft 901; set up a support frame 14 capable of supporting the front-end bearing 10 and the rear-end bearing 11, so that the front-end bearing 10 and the rear-end bearing 11 assembled on the motor shaft 901 are placed on the support frame 14, and respectively set a pressure sensor 15 and a pressure sensor 2 16 between the front-end bearing 10 and the support frame 14 and between the rear-end bearing 11 and the support frame 14, at this time, the pressure sensor 1 15 and the rear pressure sensor 2 16 both have the weight values ​​of the rotor 110 and the motor shaft 901 themselves.

[0034] Test: Apply support force F0 and downward pressure F1 to the support force point and downward pressure point of the extension shaft 902 respectively, read the pressure values ​​F01 and F02 from the pressure sensor 1 15 and the pressure sensor 2 16, increase or decrease the size of the support force F0, and make F01 and F02 equal or nearly equal. At the same time, increase or decrease the support force F0 and downward pressure F1, and make F01 and F02 equal or nearly equal, so that the pressure F01 on the front bearing 10 and the pressure F02 on the rear bearing 11 are both greater than the inherent minimum load, and record the size of the support force F0 and downward pressure F1, so as to obtain the qualified size of the support force F0 and downward pressure F1 and the appropriate ratio between the two.

[0035] After using the torque device, the qualified support force F0 and the downforce F1 as well as the appropriate ratio between the two can be easily obtained by sliding the support assembly 3 and adding or removing the counterweight block 8, see Figure 1 .

[0036] The above embodiments are only used to more clearly describe the present invention and cannot be regarded as limiting the protection scope of the present invention. Any modifications in equivalent forms should be regarded as falling within the protection scope of the present invention.

Claims

1. A hollow shaft motor test loading mechanism, characterized in that: The invention comprises an extension shaft (902) fixedly docked with the outer end of a motor shaft (901), and a torque device for applying downward pressure to the motor shaft (901) through the extension shaft (902); a support force point and a downward pressure force point are respectively arranged at the front end and the rear end of the extension shaft (902); the torque device provides an upward support force F0 and a downward pressure F1 to the support force point and the downward pressure point respectively; and the magnitude of the support force F0 and the downward pressure F1 and the ratio therebetween are adjusted so that the front end bearing (10) and the rear end bearing (11) of the motor shaft (901) in the motor (100) are subjected to a load exceeding a minimum load.

2. The hollow shaft motor test loading mechanism according to claim 1, characterized in that: A support bearing (12) and a downward pressure bearing (13) are respectively provided at the support force point and the downward pressure force point of the extension shaft (902); a support force F0 applied by the torque device to the support force point and a downward pressure F1 applied to the downward pressure force point act on the support bearing (12) and the downward pressure bearing (13) respectively.

3. The hollow shaft motor test loading mechanism according to claim 2, characterized in that: The torque device is arranged below the extension shaft (902), and comprises a support (1) and a lever (2). The lever (2) is parallel to the extension shaft (902). The front section of the lever (2) is a support arm (201), and the rear section is a downward pressure arm (202). A support component (3) capable of acting upward on the bottom of a support bearing (12) is provided at the front end of the support arm (201), and a downward pressure component (4) capable of acting downward on the top of a downward pressure bearing (13) is provided at the rear end of the downward pressure arm (202). The support component (3) is capable of sliding forward or backward on the support arm (201).

4. The hollow shaft motor test loading mechanism according to claim 3, characterized in that: The support assembly (3) and the downward pressure assembly (4) both have an elastic member, the support assembly (3) applies a support force F0 to the support bearing (12) through the elastic member, and the downward pressure bearing (13) applies a downward force F1 to the downward pressure bearing (13) through the elastic member.

5. The hollow shaft motor test loading mechanism according to claim 4, characterized in that: The elastic member is a compression spring (7).

6. The hollow shaft motor test loading mechanism according to claim 5, characterized in that: The support assembly (3) further comprises an upper seat body (301) and a lower seat body (302), wherein the upper seat body (301) is used to support the bottom of the support bearing (12), and the lower seat body (302) is pressed on the support arm (201), and the compression spring (7) is located between the upper seat body (301) and the lower seat body (302); the lower seat body (302) is provided with a downwardly opening sliding groove (3021), and the sliding groove (3021) is sleeved on the support arm (201) and can slide forward and backward on the support arm (201).

7. The hollow shaft motor test loading mechanism according to claim 4, characterized in that: The pressing assembly (4) further comprises an upper seat body (401) and a pull-down member, wherein the upper seat body (401) is pressed on the upper part of the pressing bearing (13), and the pull-down member comprises an inverted U-shaped pull-down frame (402) with an opening facing downward and a hanging column (6) passing through the rear end of the pressing arm (202), wherein the pull-down frame (402) comprises a top plate (4021), a pull-down plate (4022) and a pull-down plate (4023) suspended and fixed at both ends of the top plate (4021), and the pull-down plate (4022) is fixed to the upper and lower ends of the top plate (4021). ) and the lower ends of the pull-down plate 1 (4023) are respectively provided with hanging holes (4020). When in use, the pull-down frame (402) straddles the extension shaft (902), and the hanging holes (4020) at the lower ends of the pull-down plate 1 (4022) and the pull-down plate 2 (4023) are respectively sleeved on the two ends of the hanging column (6), the upper seat body 2 (401) and the downward pressure bearing (13) are located in the pull-down frame (402), and the extension spring (7) is pressed between the top plate (4021) and the upper seat body 2 (401).

8. The hollow shaft motor test loading mechanism according to any one of claims 3 to 7, characterized in that: It also comprises a loading hanger (5) and a counterweight (8), wherein the loading hanger (5) is suspended at the rear end of the lower pressure arm (202), and the counterweight (8) is placed on the loading hanger (5).

9. The hollow shaft motor test loading mechanism according to claim 8, characterized in that: The loading hanger (5) has a hanger rod (501), the lower end of the hanger rod has a bottom support plate (502), and the counterweight block (8) is placed on the bottom support plate (502).

10. The hollow shaft motor test loading mechanism according to claim 3, characterized in that: The installation position of the support bearing (12) on the extension shaft (902) can be shifted as the position of the support assembly (3) on the lever (2) changes.

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