CN210623414U

CN210623414U - Axial force isolation device

Info

Publication number: CN210623414U
Application number: CN201920818966.4U
Authority: CN
Inventors: 冯学明
Original assignee: Branson Ultrasonics Shanghai Co Ltd
Current assignee: Branson Ultrasonics Shanghai Co Ltd
Priority date: 2019-05-31
Filing date: 2019-05-31
Publication date: 2020-05-26
Anticipated expiration: 2029-05-31

Abstract

The present disclosure provides an axial force isolation device. The axial force isolation device comprises a first shaft, a first end cover, a first bearing, an inner retainer ring, a second bearing and a radial protruding portion, wherein the first end cover, the first bearing, the inner retainer ring, the second bearing and the radial protruding portion are sequentially arranged in the direction from the first end to the second end of the first shaft, and the radial protruding portion protrudes out of the first shaft in the radial direction. The first bearing, the inner retainer ring and the second bearing are fixedly positioned between the first end cover and the radial protrusion part by a fastening element which is in threaded connection with the first end of the first shaft, so that the axial force borne by the first shaft is transmitted to the first end cover sequentially through the radial protrusion part, the second bearing, the inner retainer ring and the first bearing. The disclosed axial force isolation device further comprises an adjusting mechanism which can eliminate the axial clearance between the first bearing and the second bearing.

Description

Axial force isolation device

Technical Field

The application relates to an axial force isolation device, in particular to an axial force isolation device applied to a rotary welding machine. Further, the present application relates to an axial force isolation device applied to a spin welder capable of adjusting an axial clearance of a bearing.

Background

A spin welder is a machine used to weld plastic parts together by friction fusion. The working process of the spin welding machine comprises the steps of applying pressure on the contact surfaces of the two plastic parts, driving one of the plastic parts to rotate through the spin motor and a possibly used coaxial speed reducer, enabling the two plastic parts to rotate relatively under the applied pressure, enabling the contact surfaces of the two plastic parts to generate a large amount of heat through friction, melting the contact parts of the two plastic parts, then stopping rotating, cooling for a certain time in a pressure-maintaining state, and finally completing welding of the two plastic parts.

Therefore, the plastic parts need to rotate relatively at a high speed and maintain a high pressure, the rotation speed is usually about 3000RPM, and the pressure between the plastic parts to be welded reaches more than 3000N. However, the motor shaft of the existing rotating motor or the reducer shaft of the standard coaxial reducer, which are hereinafter referred to as the output shaft, cannot bear a large axial load, such as an axial load of 3000N, at a rated rotation speed, such as a rotation speed of 3000 RPM.

Therefore, it is necessary to provide an axial force isolation device to isolate the axial load generated by the pressure between the plastic parts from the output shaft, so that the output shaft does not bear the axial force, thereby ensuring the normal operation of the motor or the speed reducer.

There is a rotary mechanism in a dual servo rotary friction welder in the related art that employs a thrust ball bearing to isolate axial forces. However, according to the use specification of the thrust ball bearing, the thrust ball bearing cannot bear radial load, and the limit rotating speed is low. When the thrust ball bearing is operated under a high speed condition, a contact angle between the steel ball and a radial plane of the raceway is affected by a centrifugal force, thereby causing sliding of the steel ball relative to the raceway, and adhesive wear caused by such sliding may damage the thrust ball bearing. To prevent such damage, it is necessary to ensure that the thrust ball bearing is subjected to a minimum load. In the application of the rotary welding machine, the rotating speed reaches 3000RPM, the axial force reaches more than 3000N, the abrasion of the thrust ball bearing is directly caused, and the service life of the thrust ball bearing is sharply reduced.

In addition, the axial force isolation device in the related art bears high speed and large axial force for a long time, so that a bearing between the axial force isolation device and the axial force isolation device generates a large axial gap, the axial position precision of a welding machine is reduced, the welding depth of a welding product is difficult to control, and the quality of the welding product is influenced; more seriously, it is possible to directly transmit the axial force to the output shaft, resulting in damage to the motor or the reduction gear by the axial force.

It should be noted that this background section is intended to illustrate the technical background of the application and is not intended to limit the scope of the application.

SUMMERY OF THE UTILITY MODEL

The application aims at providing an axial force isolating device, which can isolate an axial load generated in the working process of a rotary welding machine and prevent the axial load from being transmitted to an output shaft of a motor or a speed reducer.

Another object of the present application is to provide an axial force isolation device that enables adjustment of the axial clearance of the bearing of the axial force isolation device, thereby ensuring the axial positioning accuracy of the welding machine.

The present application provides, in one aspect, an axial force isolation device that can satisfy a high rotational speed (3000RPM-4500RPM), high axial force (4500N-5000N) working environment, the axial force isolation device comprising:

a first shaft rotatably disposed in the axial force isolation device and subjected to axial forces during operation; and

the first shaft is arranged in the direction from the first end of the first shaft to the second end of the first shaft in sequence:

a first end cap, the first shaft rotatably passing through a central bore of the first end cap relative to the first end cap;

the first bearing is arranged on the first shaft, and an outer ring of a first end of the first bearing abuts against the first end cover;

the first end of the inner retainer ring is abutted against the second end of the inner ring of the first bearing;

the second bearing is arranged on the first shaft, and a first end of an inner ring of the second bearing is abutted against a second end of the inner check ring; and

a radial projection projecting radially from the first shaft and abutting a second end of the inner race of the second bearing;

the first bearing, the inner retainer ring and the second bearing are fixedly positioned between the first end cover and the radial protrusion part by a fastening element which is in threaded connection with the first end of the first shaft, so that the axial force borne by the first shaft is transmitted to the first end cover sequentially through the radial protrusion part, the second bearing, the inner retainer ring and the first bearing.

With the above configuration of the present disclosure, it is possible to guide the axial force borne on the first shaft to the first end cap through the order of the radial protrusion, the second bearing, the inner retainer, the first bearing, and the first end cap, and finally the axial force is exerted on the first end cap capable of bearing the axial force, and not on the output shaft of the motor or the speed reducer.

Further, the axial force isolation device of the present disclosure further comprises:

a first outer retainer ring fixed to the first end cap outside the first bearing and abutting a second end of the outer race of the first bearing;

the two ends of the second outer retainer ring are respectively abutted with the first end of the outer ring of the second bearing and the first outer retainer ring; and

and the shell is arranged on the outer sides of the first outer retainer ring and the second outer retainer ring and is fixedly connected with the first end cover.

Further, the axial force isolation device further comprises:

a second end cap disposed on a second side of the first shaft and fixedly coupled to the housing;

the first end cover, the shell and the second end cover enclose a hollow cavity, the first shaft penetrates through the hollow cavity, and the fastening element, the first bearing, the inner retainer ring, the first outer retainer ring, the second bearing and the radial protrusion are all located in the hollow cavity.

According to the axial force isolation device of the present disclosure, the first end of the first shaft is provided with a center hole and a key groove for key-connecting the output shaft of the motor or the speed reducer to the first shaft, and the first end cap can be fixedly fitted to the casing of the motor or the speed reducer, thereby isolating the axial force transmitted to the output shaft of the motor or the speed reducer by further transmitting the axial force to the casing of the motor or the speed reducer.

The axial force isolation device according to the present disclosure further includes an adjustment mechanism capable of adjusting an axial distance between the first outer retainer ring and the second outer retainer ring, thereby eliminating an axial clearance of the first bearing and the second bearing.

Wherein the adjustment mechanism comprises:

the radial groove is arranged on the end faces, opposite to each other, of at least one of the first outer retainer ring and the second outer retainer ring, and has a bottom face which becomes gradually shallow from outside to inside;

the adjusting block is arranged between the first outer retainer ring and the second outer retainer ring and is positioned in the radial groove, and the shape of the adjusting block is complementary with that of the radial groove;

the adjusting element is arranged on the radial outer side of the adjusting block and used for pushing the adjusting block to move along the radial direction, and the adjusting block pushes the first outer retainer ring and the second outer retainer ring to move in a mode of being far away from each other along the axial direction by radial movement from the outer side to the center.

Particularly, a plurality of paired radial grooves are respectively arranged on the end faces of the first outer retainer ring and the second outer retainer ring along the circumferential direction, the radial grooves on the first outer retainer ring and the second outer retainer ring are in one-to-one correspondence with each other to form a plurality of wedge-shaped hollow grooves, and the adjusting blocks are correspondingly formed into wedge-shaped adjusting blocks.

Specifically, the adjusting element is an adjusting screw which is in threaded fit with a threaded through hole provided on the housing and a tip of which abuts a radially outer side surface of the adjusting block through the housing.

Further, the threaded through hole is formed as a stepped hole, and a stepped portion of the stepped hole is used for limiting a screwing-in depth of the adjusting screw.

According to the axial force isolation device disclosed by the invention, a first sealing ring is arranged between the first end cover and the first shaft, and a second sealing ring is arranged between the second end cover and the first shaft; in particular, a second sealing ring is provided only between the second end cap and the first shaft.

In particular, the radial projection is a shoulder integrally extending in a radial direction from the first shaft; alternatively, the radial projection may be a retainer ring that mates with the first shaft.

Preferably, the first bearing and the second bearing are angular contact ball bearings or deep groove ball bearings.

Additionally, the axial length of the central bore and the axial length of the keyway are greater than the overhanging axial length of the output shaft of the motor or reducer and the axial length of the key, respectively, so that the first shaft keyed by the key is slightly movable in the axial direction relative to the output shaft, further isolating axial forces.

Furthermore, a connecting spigot structure is arranged on the first end cover so as to be axially aligned when the first end cover is matched with the shell of the motor or the speed reducer. Specifically, the connecting spigot structure is a sunken circular step portion arranged on the end face of the first end cover and used for being matched with a boss corresponding to a shell of the motor or the speed reducer.

The technical features and effects of the present disclosure will be described in detail with reference to specific embodiments.

Drawings

FIG. 1 is a perspective schematic view of a vertical rotary welding machine according to the present disclosure;

FIG. 2 is a partial perspective view of a rotary welding machine with a die assembly according to the present disclosure;

FIGS. 3a and 3b are exploded perspective views of the lifting body assembly of a rotary welding machine according to the present disclosure, viewed in two directions;

FIGS. 4a and 4b are exploded perspective views of a ram lifting assembly of a rotary welding machine according to the present disclosure, viewed in two directions;

FIG. 5 is a cross-sectional view of a rotating assembly and an axial force isolation device of a rotary welding machine according to the present disclosure;

FIGS. 6a and 6b are schematic perspective views of a first outer retainer ring of an axial force isolation device according to the present disclosure, viewed in two directions;

FIG. 7 is a schematic perspective view of a second outer retainer ring of an axial force isolation device according to the present disclosure;

FIG. 8a is a schematic perspective view of an adjustment block of an axial force isolation device according to the present disclosure;

FIGS. 8b and 8c are side schematic views of an adjustment block of an axial force isolation device according to the present disclosure;

FIG. 9 is a plan view schematic of a first end cap of an axial force isolation device according to the present disclosure.

Detailed Description

The rotary welding machine can be used for welding workpieces such as plastics or metals which can be melted under high pressure and friction and are integrally formed after being cooled; meanwhile, the welding machine can be divided into a vertical type rotary welding machine and a horizontal type rotary welding machine according to different pressing directions. One embodiment of the present application will now be described, by way of example, with reference to the accompanying drawings, figures 1-9, in which: a vertical plastic spin welder with an axial force isolation device.

Referring to fig. 1 and 2, a rotary welder 10 is shown according to a first embodiment of the present disclosure. The spin welder 10 may have a die assembly 20 mounted thereon, and the die assembly 20 may have a plastic workpiece 30 secured thereto to be welded. Wherein, this spin welding machine 10 includes: a stand 100, the stand 100 for integrally supporting the spin welder 10; a frame 200, the lower end of which frame 200 is fixedly mounted on the frame 100 and extends in a direction perpendicular to the frame 100, so that the whole of the spin welder 10 can be extended in the direction, providing a sufficient operating space for the installation of the die assembly 20; a lifting assembly 300, the lifting assembly 300 being mounted on the frame 200 such that the ram assembly 400 mounted on the lifting assembly 300 can move on the frame 200 to provide the mold assembly 20 with a suitable initial height; the ram assembly 400 is mounted on the lifting assembly 300 and enables the rotating assembly 500 mounted on the ram assembly 400 to move up and down relative to the ram assembly 400 to provide the required pressure to the plastic workpiece 30; the rotating assembly 500 is mounted on the ram assembly 400 to provide the required rotational force to the plastic workpiece 30; and an axial force isolation device 600, the axial force isolation device 600 being installed at an output end of the rotating assembly 500, for transmitting the rotating force provided by the rotating assembly 500 to the mold assembly 20 and isolating an axial force fed back from the mold assembly 20 for an output shaft of the rotating assembly 500.

Referring to fig. 2, the mold assembly includes an upper mold 21 and a lower mold 22; the plastic workpiece 30 includes an upper workpiece 31 and a lower workpiece 32. The machine base 100 is provided with a worktable 101, the worktable 101 can be provided with a lower die 22, and the lower die 22 is used for fixing the lower workpiece 32. The lower end of the axial force isolation device 600 may be mounted with an upper die 21, the upper die 21 being used to secure the upper workpiece 31.

Referring to fig. 3a and 3b, the lifting assembly 300 comprises a lifting body 301, a lifting body motor 302, a lifting body screw 303, a lifting body nut 304, a lifting body guide 305 and a lifting body slider 306. Wherein, the lifting body motor 302 is fixed on the upper end of the frame 200 and drives the lifting body screw 303 to rotate. The lifting body screw 303 and the lifting body guide 305 are fixed to the frame 200 and extend in the direction in which the frame 200 extends. The lifting body nut 304 is threadedly coupled to the lifting body screw 303 to convert rotation of the lifting body screw 303 into linear motion of the lifting body nut 304. Meanwhile, the lifting body nut 304 is fixedly connected with the lifting body 301 through a bolt, so that the lifting body nut 304 also drives the lifting body 301 to do linear motion. The lifting body block 306 is fixed to the lifting body 301 and slidably coupled to the lifting body guide 305 such that the linear motion of the lifting body 301 is supported and positioned by the lifting body guide 305. Finally, it is achieved that the lifting body 301 moves linearly up and down along the lifting body guide 305 as the lifting body motor 302 rotates to provide the desired working height of the mold assembly 20.

It is conceivable that the lifting body screw 303 and the lifting body nut 304 cooperate to perform the lifting function, and may be replaced by a combination of an air cylinder and a fixing block. Wherein, the cylinder is installed on frame 200, and the fixed block is installed on the cylinder head and with lifting body 301 fixed connection to realize lifting body 301 the ascending removal in the straight line direction.

Referring to fig. 4a and 4b, the ram assembly 400 is fixedly mounted on the lifting body 301 of the lifting assembly 300, and includes a ram lifting bracket 401, a ram lifting motor 402, a ram screw 403, a ram guide 405, and a ram slider 406. The ram lifting bracket 401 is fixed to the lifting body 301 by screws, for example. The ram lifting motor 402 is fixed to the upper end of the ram lifting bracket 401 and drives the ram screw 403 mounted on the ram lifting bracket 401 to rotate. The ram guide 405 is fixed to the ram raising and lowering frame 401 and extends in the direction in which the frame 200 extends. The feed screw nut 504 of the rotary assembly 500 is threadedly coupled to the ram screw 403 and is integrally formed with the motor mounting 507 of the rotary assembly 500. It will be appreciated by those skilled in the art that the lead screw nut 504 may also be secured to the motor mount 507. The feed screw nut 504 converts the rotation of the pressure head feed screw 403 into a linear motion of the pressure head nut 504, and the pressure head nut 504 drives the motor mounting bracket 507 to make a linear motion. The ram block 406 is secured to the motor mount 507 and is slidably coupled to the ram guide track 405 such that linear movement of the motor mount 507 is supported and positioned by the ram guide track 405. Finally, as the ram lift servo motor 402 rotates, the motor mount 507 of the rotary assembly 500 moves linearly along the ram guide track 405 to provide the pressure required for welding.

It is contemplated that the combination of ram screw 403 and screw nut 504 to achieve the lifting function may be replaced by a combination of a cylinder and a fixed block. Wherein, the cylinder is installed on pressure head lifting support 401, and the fixed block is installed on the cylinder head and with motor mounting 507 fixed connection to realize the removal of motor mounting 507 on the rectilinear direction.

It will be appreciated that in another embodiment, the lift assembly 300 may not be provided, and thus the ram assembly 400 may not be fixed to the lift assembly 300, but rather directly to the frame 200, except that in such a case the vertical position of the ram assembly cannot be adjusted.

Referring to fig. 4a and 5, the rotating assembly 500 includes a motor 501 outputting a rotational force in addition to a motor mounting bracket 507 and a ram nut 504, wherein a motor housing 502 of the motor 501 is fixed to the motor mounting bracket 507, and a motor shaft 503 of the motor 501 is disposed parallel to the frame 200. Preferably, rotating assembly 500 further includes a speed reducer coupled to motor 501 for reducing the output rotational speed of rotating assembly 500.

It will be appreciated that the ram assembly 400 may not be provided if the rotation assembly 500 is capable of providing sufficient axial pressure while providing rotational force.

An axial force isolation device 600 is mounted on the rotating assembly 500 to ensure that axial forces are not transmitted to the motor or reducer shaft 503. The axial force isolation device 600 includes a first shaft 601, the first shaft 601 is provided with an input end center hole and a key groove 601a at an upper end, and the motor shaft 503 is keyed to the first shaft 601 through the input end center hole and the key groove 601a to be rotated together. Alternatively, the rotating electrical machine 501 may be connected to a reduction gear, and then the reduction gear shaft may be connected to the first shaft 601. The lower end of the first shaft 601 is provided with an output end key slot 601b, and the upper die 21 can be fixedly connected with the first shaft 601 in the rotation direction through the output end key slot 601b, and can fix the upper workpiece 31 on the upper die 21. Finally, the rotational force output by the rotating motor 501 is transmitted to the upper workpiece 31, so that the upper workpiece 31 rotates relative to the lower workpiece 32, and the frictional force required for welding is provided. The first end cap 602 for receiving the axial force is fixedly connected to the motor housing 502, and the first end cap 602 defines a central hole for the first shaft 601 to pass through. The housing 603 is arranged substantially along the outer circumference of the first end cap 602 and is fixedly connected to the first end cap 602 by screws to form a hollow cavity. The second end cap 604 is disposed on the opposite side of the housing 603 from the first end cap 602, and is fixedly connected to the housing 603 by screws to close the hollow cavity, and the second end cap 604 is provided with a central hole for the first shaft 601 to pass through.

As such, the first shaft 601 may be disposed through the first and second end caps 602 and 604 and the hollow cavity.

In addition, the axial force isolation device 600 further includes the following components sequentially sleeved on the first shaft 601 and located inside the hollow cavity: a first bearing 605, a first end of an outer race of the first bearing 605 abutting the first end cap 602; an inner retainer 606, a first end of the inner retainer 606 abutting a second end of the inner race of the first bearing 605; in the second bearing 607, the second end of the inner retainer 606 abuts against the first end of the inner race of the second bearing 607. The first shaft 601 is further formed with a radial protrusion 608, the radial protrusion 608 protrudes radially from the first shaft 601, and the radial protrusion 608 abuts against a second end of the inner race of the second bearing 607.

More specifically, the radial projection 608 is here a shoulder extending integrally radially from the first shaft 601. The first bearing 605, the inner retainer ring 606 and the second bearing 607 are fastened on the first shaft against the radial projection 608 by a fastening element 609 screwed to one end of the first shaft 601. The fastening element 609 provides axial pretension to the inner ring of the first bearing 605 and the inner ring of the second bearing 607. It is easily conceivable that the radial protrusion 608 may be provided as a separate retainer ring or the like.

Due to the structure of the axial force isolation device 600 disclosed by the disclosure, when the rotary welding machine 10 works, the axial force applied to the first shaft 601 through the upper die 21 is transmitted to the first end cover 602 sequentially through the radial protrusion 608, the second bearing 607, the inner retainer 606 and the first bearing 605, so that the transmission of the axial force to the output shaft 503 of the motor or the speed reducer is prevented, and the technical effect of isolating the axial force is achieved.

It should be noted that, as can be seen from fig. 5, the first end cover 602 only contacts with the outer ring of the first bearing 605 but not with the inner ring thereof, so that the axial force applied to the inner rings of the first bearing 605 and the second bearing 607 is isolated by being transmitted to the outer ring thereof and finally transmitted to the first end cover 602, and thus the first bearing 605 and the second bearing 607 are subjected to a force which makes the inner ring and the outer ring thereof staggered with each other during the operation, and over time, a mutual staggered axial gap is formed between the inner ring and the outer ring of the bearing, which affects the positioning accuracy of the first shaft.

As shown in fig. 5, 6a and 6b, the axial force isolation device 600 further includes: and a first outer retainer 610, the first outer retainer 610 having an inner surface 617 engaging an outer side of the first bearing 605 and a step portion 618 abutting a second end of the first bearing 605. In particular, the first outer collar abuts the second end of the outer ring of the first bearing and is fixed to the first end cap 602, in particular here by screws fixing the first end cap 602 and the housing 603. Whereby both ends of the inner ring of the first bearing 605 are positioned by the fastening element 609 and the inner retainer ring 606, respectively; and the outer ring of the first bearing 605 is positioned by the first end cover 602 and the first outer retainer ring 610, respectively, so that the first bearing 605 is fixedly mounted on the first shaft 601.

As shown in fig. 6a and 6b, the first outer retainer ring 610 further has a skirt 610a, and the skirt 610a has a mounting hole 610b for fixing the first outer retainer ring 610 between the first end cap 602 and the housing 603, so that the first outer retainer ring 610 becomes a fixing member.

As shown in fig. 5 and 7, the axial force isolation device 600 further includes a second outer retainer ring 611, one end of the second outer retainer ring 611 abuts against a first end of the outer ring of the second bearing 607, and the other end of the second outer retainer ring 611 abuts against the first outer retainer ring 610. Similarly, the second bearing 607 is positioned by an inner retainer ring 606, a second outer retainer ring 611, a radial projection 608, and the housing 603.

To enable adjustment of the bearing play of the first bearing 605 and the second bearing 607, the axial force isolation device 600 further comprises an adjustment mechanism that is capable of adjusting the axial distance between the first outer retainer ring 610 and the second outer retainer ring 611. As shown in fig. 6a, 6b and 7, the adjustment mechanism includes: and a radial groove 612, the radial groove 612 extending in the radial direction on the contact end surface of the first outer retainer ring 610 and the second outer retainer ring 611 and preferably being provided in plurality in the circumferential direction, and the radial groove 612 having a side surface parallel to a radial straight line of the first shaft 601 and a bottom surface gradually becoming shallower from the outside to the inside.

An adjustment block 613 is fitted in the radial groove 612. As shown in fig. 8a to 8c, the adjustment block 613 has a shape complementary to the shape of the radial groove 612, and is formed in a wedge shape in one direction. Specifically, the upper and lower surfaces are formed in an inclined plane shape to fit the bottom surface of the radial groove 612, the left and right surfaces are formed in parallel side surfaces to fit the side surfaces of the radial groove 612, and the front and rear surfaces are formed in an arc-shaped surface to conform to the outer ring.

The adjustment screw 614 is abutted on the radially outer side of the adjustment block 613 through the threaded through hole of the housing 603, and the adjustment screw 614 is screwed with the threaded through hole of the housing 603. Rotating the adjusting screw 614 can move the adjusting screw in the radial direction while pushing the adjusting block 613 to move in the radial direction, and since the adjusting block 613 is formed in a wedge shape, the adjusting block 613 applies an axial force to the first outer retainer ring 610 and the second outer retainer ring 611 while moving in the radial direction, so that the first outer retainer ring 610 and the second outer retainer ring 611 are axially displaced away from each other to adjust the distance between the first outer retainer ring 610 and the second outer retainer ring 611.

According to the above design, it is possible to increase the distance between the first outer retainer ring 610 and the second outer retainer ring 611 by screwing the adjustment screw 614, and thereby increase the distance between the outer ring of the first bearing 605 and the outer ring of the second bearing 607, while the respective bearing clearances of the first bearing 605 and the second bearing 607 can be adjusted simply and efficiently in the case where the fastening member 609 has fixed the inner ring of the first bearing 605 and the inner ring of the second bearing 607.

In addition, the above design also increases a transmission path of the axial force, namely, the axial force is transmitted to the first end cover 602 from the radial protrusion 608 through the second bearing 607, the second outer retainer ring 611, the first outer retainer ring 610 and the first bearing 605. It is contemplated that the first outer retainer ring 610 and the second outer retainer ring 611 may also be present as a single unitary member if only for the purpose of transmitting axial forces.

Preferably, a first sealing ring 615 is disposed between the first shaft 601 and the first end cap 602, and a second sealing ring 616 is disposed between the first shaft 601 and the second end cap 604, so that the hollow cavity is sealed, thereby not only preventing external dust and the like from entering the hollow cavity, but also being beneficial to storing lubricating substances inside the hollow cavity, and further prolonging the service life of parts inside the hollow cavity.

Preferably, the threaded through hole of the housing 602, which is engaged with the adjustment screw 614, is formed as a stepped hole, and the stepped portion of the stepped hole is used to limit the screwing depth of the adjustment screw 614 and limit the adjustment screw 614 from being screwed too much.

Preferably, the first bearing 605 and the second bearing 607 adopt angular contact ball bearings to bear large axial force; deep groove ball bearings may also be used if the axial forces experienced on the first shaft 601 are small.

Preferably, a floating design is adopted between the first shaft 601 and the motor shaft 503 or the reducer shaft, that is, the lengths of the central hole and the key groove 601a in the axial direction are respectively greater than the lengths of the protruding axial direction of the motor shaft 503 or the reducer shaft and the length of the key, so that a certain margin is left in the axial direction, and the two can move relatively in the axial direction to prevent the motor or the reducer from being damaged due to the axial play of the first shaft 601.

It is contemplated that the first outer retainer ring 610 may also be secured to the second end cap 604 or the housing 603. Furthermore, a person skilled in the art may fix the first outer retainer ring 610, but fix the second outer retainer ring 611 on the first end cover 602 or the second end cover 604 or the housing 603, so that the first outer retainer ring 610 is fixed by the limiting action of the adjusting block 613 in the circumferential direction, so as to fix the outer ring of the first bearing 605 and the outer ring of the second bearing 607.

In the above embodiment, the adjusting block has a wedge-shaped configuration with two inclined sides. But the configuration of adjustment block 613 has more flexibility. For example, only one side surface is formed as an inclined surface, and accordingly, only one corresponding side of the first outer retainer ring 610 or the second outer retainer ring 611 is provided with a radial groove 612 which is matched with the side surface.

According to the above embodiment, the outer side of the outer ring of the first bearing 605 and the second bearing 607 may abut against the first outer retainer ring 610 or the second outer retainer ring 611 or the housing 603 according to actual conditions, so that the outer ring of the first bearing 605 and the second bearing 607 is well fixed.

Referring to fig. 9, the first end cap 602 is provided with a connection screw hole 602a and a connection spigot structure 602 b. The first end cap 602 is fixed to the motor case 502 or the reduction gear case through the coupling screw hole 602 a. The connecting spigot structure 602b is a circular step portion sunk from the end face of the first end cover 602, and is used for matching with a corresponding boss of the motor housing 502 to ensure correct axial alignment of the first end cover 602 and the motor housing 502, so that axial alignment of the first shaft 601 and the motor shaft 503 is further ensured, and axial and radial component forces on the motor shaft 503 due to axial misalignment are prevented.

Because the motor housing 502 and the first end cap 602 are fixed by the connecting seam allowance structure, the first sealing ring 615 may not be arranged between the first shaft 601 and the first end cap 602, that is, the second sealing ring 616 is only arranged between the first shaft 601 and the second end cap 604, and thus satisfactory sealing performance can be achieved.

The present application discloses an embodiment and mentions some possible alternatives, which are all within the scope of the present application. In addition, certain obvious modifications that would be recognized by one of ordinary skill in the art would also fall within the scope of the present application.

Claims

1. An axial force isolation device, comprising:

the first bearing is arranged on the first shaft, and a first end of an outer ring of the first bearing is abutted against the first end cover;

the first bearing, the inner retainer ring and the second bearing are fastened and positioned between the first end cover and the radial protrusion by a fastening element connected to the first end of the first shaft, so that the axial force borne by the first shaft is transmitted to the first end cover sequentially through the radial protrusion, the second bearing, the inner retainer ring and the first bearing.

2. The axial force isolation device of claim 1, further comprising:

a first outer retainer ring fixed to the first end cap outside the first bearing and abutting a second end of an outer race of the first bearing;

3. The axial force isolation device of claim 2, further comprising:

the first end cover, the housing and the second end cover enclose a hollow cavity, the first shaft penetrates through the hollow cavity, and the fastening element, the first bearing, the inner retainer ring, the first outer retainer ring, the second bearing and the radial protrusion are all located in the hollow cavity.

4. The axial force isolation device of claim 2 or 3, further comprising an adjustment mechanism capable of adjusting an axial distance between the first outer retainer ring and the second outer retainer ring to eliminate axial play of the first bearing and the second bearing.

5. The axial force isolation device of claim 4, wherein the adjustment mechanism comprises:

6. The axial force isolation device of any one of claims 1 to 3, wherein the first end of the first shaft is provided with a central hole and a key groove for keying an output shaft of a motor or reducer to the first shaft, and the first end cap is capable of being fixedly fitted to a housing of the motor or reducer so as to isolate an axial force transmitted to the output shaft of the motor or reducer by further transmitting the axial force to the housing of the motor or reducer.

7. The axial force isolation device of claim 5, wherein a plurality of pairs of radial grooves are circumferentially arranged on the end faces of the first outer retainer ring and the second outer retainer ring, the radial grooves on the first outer retainer ring and the second outer retainer ring are in one-to-one correspondence to form a plurality of wedge-shaped hollow grooves, and the adjusting blocks are correspondingly formed as wedge-shaped adjusting blocks.

8. The axial force isolation device of claim 5, wherein the adjustment element is an adjustment screw threadedly engaged with a threaded through-hole provided on the housing and a tip of the adjustment screw passes through the housing and abuts a radially outer side surface of the adjustment block.

9. The axial force isolation device of claim 8, wherein the threaded through bore is formed as a stepped bore, the step of the stepped bore for limiting a depth of threading of the adjustment screw.

10. The axial force isolation device of claim 3, wherein a seal ring is disposed between the second end cap and the first shaft.

11. The axial force isolation device of any one of claims 1 to 3, wherein the radial projection is a shoulder integrally extending in a radial direction from the first shaft or a retainer ring engaged with the first shaft.

12. The axial force isolation device of any one of claims 1 to 3, wherein the first bearing and the second bearing are angular contact ball bearings or deep groove ball bearings.

13. The axial force isolation device of claim 6, wherein the axial length of the central bore and the axial length of the keyway are greater than the axial length of an overhang with the output shaft of the motor or reducer and the axial length of a key, respectively, such that the first shaft keyed by the key is slightly movable in an axial direction relative to the output shaft, further isolating axial forces.

14. The axial force isolation device of claim 6, wherein the first end cap has a connection spigot structure thereon to axially align when the first end cap is mated with the motor or reducer housing.

15. The axial force isolation device of claim 14, wherein the connection spigot structure is a sunken circular step portion provided on an end face of the first end cap for mating with a boss corresponding to a housing of the motor or the reducer.