Linear drive mechanism

Abstract

The present invention provides a linear drive mechanism, comprising a housing, a front cover, a rear cover, a stator and a rotor. The linear drive mechanism further comprises a rolling lead screw sleeved in the rotor, a first bearing and a second bearing. The rolling lead screw comprises a central lead screw and a lead screw nut extending in the axial direction of the rotor, the lead screw nut being fixed in the second bearing, and the lead screw nut being sleeved on the central lead screw and being rotationally connected to the central lead screw. The rotor comprises a hollow rotor body and an annular boss protruding and extending from the end of the rotor body close to the front cover along the periphery of the rotor body, wherein the end of the rotor body away from the front cover is fixed to the first bearing, and the boss is fixed to one end of the lead screw nut. The rotor rotates to drive the lead screw nut to rotate, such that the lead screw nut rotates to drive the central lead screw to implement linear extension and retraction motion. Compared with the prior art, the linear drive mechanism of the present invention achieves a good linear drive effect, and helps to shorten the length of the lead screw nut, thus saving costs and saving installation space.

Description

Linear drive mechanism Technical Field

[0001] The present invention relates to the field of linear drive technology, and in particular to a linear drive mechanism. Background Art

[0002] The rapid development of the artificial intelligence and robotics industries is placing stricter demands on linear actuators due to space and energy efficiency requirements. These actuators are moving towards higher integration, smaller size, higher load capacity, and faster response. A linear drive mechanism is a type of linear actuator that uses a lead screw as the active element and a nut as the linear output. This means the nut does not rotate but telescopes along its axis, while the lead screw rotates. Technical issues

[0003] In the related art, standard linear screw actuators mostly use coaxial transmission mechanisms, where the motor extends the shaft through gears or couplings, rotates the shaft, and pushes the nut to move forward or backward axially. Alternatively, they use parallel transmission mechanisms, where the power source, such as an electric motor or internal combustion engine shaft, outputs torque, which is transmitted to parallel screw shafts through gears or belts. However, in standard planetary roller screws, the screw shaft is always the active element. If the motor is used as the power source, the motor rotor shaft and the planetary roller screw shaft are integrated together. The motor has a large outer diameter, and the planetary roller screw nut also has a certain size. The two are spatially arranged in a series structure along the axial direction. At the same time, for system safety, a housing must be provided to constrain the outer diameter of the motor stator and the outer part of the nut into a single integral housing, which increases the overall size of the planetary roller screw linear actuator.

[0004] Therefore, it is necessary to provide a new linear drive mechanism to solve the above technical problems. Technical Solutions

[0005] The object of the present invention is to provide a linear drive mechanism which has good linear drive effect, is convenient for shortening the length of the lead screw nut, saves costs, and saves installation space.

[0006] To achieve the above-mentioned object, the present invention provides a linear drive mechanism, comprising a housing, a front cover and a rear cover respectively fixed to opposite ends of the housing, a stator disposed within the housing, and a hollow rotor disposed within the stator and rotatably connected to the stator; the linear drive mechanism further comprises a rolling screw sleeved within the rotor, a first bearing sleeved on the rotor and fixed to one end of the rear cover, and a second bearing sleeved on the rolling screw and fixed within the housing;

[0007] The rolling screw includes a central screw provided on the inner circumference of the rotor and passing through the front cover, and a screw nut extending along the axial direction of the rotor, wherein the screw nut is fixed in the second bearing, and the screw nut is sleeved on the central screw and forms a rotational connection with the central screw;

[0008] The rotor includes a hollow rotor body and an annular boss extending from one end of the rotor body close to the front cover along the outer circumference of the rotor body. The end of the rotor body away from the front cover is fixed to the first bearing, and the boss is inserted and fixed to the end of the lead screw nut close to the rear cover. The rotation of the rotor drives the lead screw nut to rotate, so that the rotation of the lead screw nut drives the central lead screw to realize linear telescopic motion.

[0009] Preferably, the rolling screw is a planetary roller screw, and the screw nut includes a first nut body with a threaded structure, a first bearing stopper formed on the circumference of the first nut body, a first annular mounting groove and a second annular mounting groove formed by depressions at two ends of an inner wall of the first nut body, a first gear ring fixedly arranged in the first mounting groove, a second gear ring fixedly arranged in the second mounting groove, and a plurality of annular screw rod columns arranged around the central screw, the two ends of each annular screw rod column being respectively arranged on the first gear ring and the second gear ring to form a rotational connection; the first nut body is fixed in the second bearing, and the first bearing stopper abuts against a side of the second bearing close to the rear cover; the boss is fixedly arranged in the first mounting groove and abuts against the first gear ring;

[0010] The center screw includes a first center screw body arranged in the rotor and provided with a threaded structure, and a first protruding end extended from one end of the first center screw body close to the front cover; the first center screw body is respectively engaged with each of the annular screw columns, and each of the annular screw columns is engaged with the first nut body, and the first protruding end passes through the front cover.

[0011] Preferably, the rolling screw is a ball screw, and the screw nut includes a second nut body, a first ball groove in a threaded shape recessed on the inner circumference of the second nut body, a second bearing stopper formed on the outer circumference of the second nut body, a third mounting groove recessed inwardly from an end of the second nut body away from the front cover, and a plurality of balls disposed in the first ball groove; the second nut body is disposed in the second bearing, and the second bearing stopper abuts against a side of the second bearing close to the rear cover;

[0012] The center screw includes a second center screw body arranged in the rotor and a second protruding end extended from one end of the second center screw body close to the front cover; a second ball groove in the shape of a thread is formed by a depression on the outer periphery of the second center screw body, the first ball groove and the second ball groove are arranged correspondingly, and the balls are clamped between the first ball groove and the second ball groove so that the second center screw body and the second nut body form a rolling connection.

[0013] Preferably, the linear drive mechanism further comprises a stopper sleeved and fixed on the lead screw nut, wherein the stopper abuts against a side of the second bearing close to the front cover.

[0014] Preferably, the diameter of the rotor is smaller than the diameter of the screw nut.

[0015] Preferably, the rotor further comprises an iron core sleeved and fixed on the rotor body and a plurality of permanent magnets fixed on the iron core, and each of the permanent magnets is spaced apart from the stator.

[0016] Preferably, the linear drive mechanism further includes a position sensor, which includes a collecting part fixed to the rear cover and a rotating part fixed to the rotor, and the collecting part and the rotating part are arranged relative to each other and spaced apart.

[0017] Preferably, the motor formed by the stator and the rotor together adopts an 8-pole 9-slot structure, a 10-pole 12-slot structure, a 14-pole 12-slot structure, or a 16-pole 12-slot structure.

[0018] Preferably, the position sensor is a Hall position sensor, a magnetic encoding position sensor or an optical encoding position sensor.

[0019] Preferably, the linear drive mechanism further comprises a base which is sleeved and fixed on a side of the rotor close to the rear cover, and the rotating part is fixed to the base.

[0020] Preferably, the linear drive mechanism further includes a bearing chamber, the bearing chamber is sleeved and fixed to the first bearing, and the outer peripheral side of the bearing chamber is fixedly connected to the inner wall of the housing. Beneficial effects

[0021] Compared with the prior art, the linear drive mechanism of the present invention drives the rotor to rotate within the housing through the stator, a center screw is arranged within the rotor, a screw nut is arranged to extend axially along the rotor, the screw nut is fixed in the second bearing, and the screw nut is rotatably sleeved on the center screw; the rotor includes a hollow rotor body and a boss extending radially and annularly from the end of the rotor body near the front cover, and the end of the rotor body away from the front cover is fixed to the first bearing, so that the boss and the screw nut are integrated into a one-piece structure, and the rotation of the rotor drives the screw nut to rotate, so that the screw nut rotates and drives the center screw to achieve linear telescopic motion; through the installation arrangement of the first bearing and the second bearing, when the rotor rotates, the screw nut does not move axially. The rotor transmits torque to the center screw during the rotation of the screw nut, which is converted into thrust. Because the screw nut is restricted from axial movement, the center screw is pushed axially according to the interaction of forces, thereby achieving the linear drive motion function. At the same time, the rolling screw is sleeved into the inner wall of the rotor, which effectively shortens the length of the screw nut, and the screw nut can be processed independently, simplifying the process. Further save costs and save installation space. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive work, among which:

[0023] FIG1 is a schematic diagram of the three-dimensional structure of a linear drive mechanism provided in Example 1 of the present invention;

[0024] FIG2 is an exploded perspective view of the linear drive mechanism according to the first embodiment of the present invention;

[0025] FIG3 is a cross-sectional view taken along line AA of FIG1 ;

[0026] FIG4 is a schematic diagram of the three-dimensional structure of a linear drive mechanism provided in Embodiment 2 of the present invention;

[0027] FIG5 is a cross-sectional view taken along line BB in FIG4 . Modes for Carrying Out the Invention

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0029] Example 1

[0030] As shown in Figures 1 to 3, an embodiment of the present invention provides a linear drive mechanism 100, including a housing 1, a front cover 3 and a rear cover 2 respectively fixed to opposite ends of the housing 1, a stator 4 arranged in the housing 1, and a hollow rotor 5 arranged in the stator 4 and rotatingly connected to the stator 4; the linear drive mechanism 100 also includes a rolling screw 6 sleeved on the rotor 5, a first bearing 7 sleeved on the rotor 5 and fixed to the rear cover 2, and a second bearing 8 sleeved on the rolling screw 6 and fixed in the housing 1.

[0031] In this embodiment, the first bearing 7 is a deep groove ball bearing, the second bearing 8 is a four-point contact bearing or an angular contact bearing, and the rolling screw 6 can be a planetary roller screw. The first bearing 7 and the second bearing 8 provide radial and axial constraints on the rolling screw 6, facilitating its linear telescopic motion driven by the rotor 5.

[0032] The linear drive mechanism 100 further includes a bearing chamber 12 , which is sleeved and fixed to the first bearing 7 , and the outer circumference of the bearing chamber 12 is fixedly connected to the inner wall of the housing 1 , so as to facilitate the installation and fixation of the first bearing 7 .

[0033] In this embodiment, preferably, the front cover 3 and the rear cover 2 are detachably fixed to both ends of the housing 1. Optionally, the front cover 3 is snap-fitted or buckled to the housing 1, and the rear cover 2 is snap-fitted or buckled to the housing 1 for easy assembly.

[0034] Of course, the housing 1 may be fixedly connected to the front cover 3 and the rear cover 2 respectively through welding process, which has a better fixing effect.

[0035] The rolling screw 6 includes a center screw 61 arranged on the inner circumference of the rotor 5 and passing through the front cover 3, and a screw nut 62 extending along the axial direction of the rotor 5. The screw nut 62 is fixed in the second bearing 8. The screw nut 62 is rotatably sleeved on the center screw 61 and forms a rotational connection with the center screw 61.

[0036] The rotor 5 includes a hollow rotor body 51 and an annular boss 52 extending from the end of the rotor body 51 close to the front cover 3 along the outer periphery of the rotor body 51. The end of the rotor body 51 away from the front cover 3 is fixed to the first bearing 7. The boss 52 is inserted and fixed to the end of the screw nut 62 close to the rear cover 2. The rotor 5 rotates to drive the screw nut 62 to rotate, so that the screw nut 62 rotates to drive the center screw 61 to achieve linear telescopic motion. Optionally, the boss 52 and the screw nut 62 can be threadedly connected to form an integral structure, or can be pinned to form an integral structure. After connection, the rotor 5 and the screw nut 62 can rotate coaxially. The screw nut 62 rotates synchronously with the rotor 5 as the active component, and the center screw 61 performs axial telescopic operation.

[0037] Specifically, the rotor 5 is driven to rotate in the casing 1 by the stator 4, the center screw 61 is set in the rotor 5, the screw nut 62 is arranged axially along the rotor 5, the screw nut 62 is fixed in the second bearing 8, and the screw nut 62 is rotatably sleeved on the center screw 61; the rotor 5 includes a hollow rotor body 51 and a boss 52 extending radially in an annular shape from the end of the rotor body 51 close to the front cover 3, the end of the rotor body 51 away from the front cover 3 is fixed to the first bearing 7, the boss 52 and the screw nut 62 are an integrally formed structure, and the rotation of the rotor 5 drives the screw nut 62 to rotate, so that the screw nut 62 rotates to drive the center screw 61 to achieve linear telescopic motion. By installing the first bearing 7 and the second bearing 8, the screw nut 62 will not move axially when the rotor 5 rotates. The rotor 5 transmits torque to the center screw 61 during the rotation of the screw nut 62, which is converted into thrust. Because the screw nut 62 is restricted from axial movement, the center screw 61 will be pushed axially according to the interaction of forces, realizing the linear drive motion function. At the same time, fitting the rolling screw 6 into the inner wall of the rotor 5 will effectively shorten the length of the screw nut 62. The screw nut 62 can be processed independently, simplifying the process and reducing the processing difficulty. Further saving costs, the overall center screw 61 has a large bearing capacity and saves installation space.

[0038] In this embodiment, the screw nut 62 includes a first nut body 621 with a threaded structure, a first bearing stop 622 formed on the circumferential side of the first nut body 621, a first mounting groove 623 and a second mounting groove 624 formed by depressions at both ends of the inner wall of the first nut body 621, a first gear ring 625 fixedly arranged in the first mounting groove 623, a second gear ring 626 fixedly arranged in the second mounting groove 624, and a plurality of annular screw columns 627 arranged around the central screw 61, the two ends of each annular screw column 627 being respectively arranged on the first gear ring 625 and the second gear ring 626 to form a rotational connection; the first nut body 621 is fixed in the second bearing 8, and the first bearing stop 622 abuts the side of the second bearing 8 close to the rear cover 2; the boss 52 is fixed in the first mounting groove 623 and abuts the first gear ring 625.

[0039] The central screw 61 includes a first central screw body 611 disposed within the rotor 5 and having a threaded structure, and a first protruding end 612 extending from one end of the first central screw body 611 near the front cover 3. The first central screw body 61 is respectively engaged with each of the annular screw posts 627, each of which is engaged with the first nut body 621. The first protruding end 612 is disposed through the front cover 3. A plurality of annular screw posts 627 are mounted via a first gear ring 625 and a second gear ring 626, such that the first central screw body 611 is engaged with the plurality of annular screw posts 627, and the plurality of annular screw posts 627 are engaged with the first nut body 621. The rotor 5 is driven by the stator 4 to rotate the first nut body 621, which in turn drives the plurality of annular screw posts 627 to rotate, thereby driving the central screw 61 to perform linear telescopic motion.

[0040] In this embodiment, the linear drive mechanism 100 further includes a stopper 9 that is sleeved and fixed to the screw nut 62. The stopper 9 abuts the side of the second bearing 8 that is closer to the front cover 3. The stopper 9 abuts one end of the second bearing 8 and the locking bolt abuts the other end, thereby ensuring that the axial position of the screw nut 62 is restricted.

[0041] In this embodiment, the diameter of the rotor 5 is smaller than the diameter of the screw nut 62. This facilitates the installation and fixing of the end of the rotor 5 close to the front cover 3 into the end of the screw nut 62, and facilitates integrated assembly.

[0042] In this embodiment, the rotor 5 further includes an iron core 53 sleeved and fixed to the rotor body 51, and a plurality of permanent magnets 54 fixed to the iron core 53. Each permanent magnet 54 is spaced apart from the stator 4. By assembling the permanent magnets 54 on the iron core 53, or alternatively, surface-mounting the permanent magnets 54 on the outer circumference of the iron core 53, or embedding the permanent magnets 54 within the iron core 53, the permanent magnets 54 are effectively secured.

[0043] In this embodiment, the linear drive mechanism 100 further includes a position sensor 10. The position sensor 10 comprises a collecting portion 101 fixed to the rear cover 2 and a rotating portion 102 fixed to the rotor 5. The collecting portion 101 and the rotating portion 102 are spaced apart relative to each other. As the rotating portion 102 rotates with the rotor 5, the collecting portion 101 collects information such as the angle and number of revolutions of the rotating portion 102, thereby obtaining the corresponding extension and retraction distance of the center screw 61.

[0044] In this embodiment, the motor formed by the stator 4 and the rotor 5 adopts an 8-pole 9-slot structure, a 10-pole 12-slot structure, a 14-pole 12-slot structure, or a 16-pole 12-slot structure. For example, an 8-pole 9-slot structure represents 8 permanent magnet poles and 9 stator slots.

[0045] In this embodiment, the position sensor 10 is a Hall position sensor, a magnetic encoding position sensor or an optical encoding position sensor.

[0046] In this embodiment, the linear drive mechanism 100 further includes a base 11 that is sleeved and fixed to the side of the rotor 5 near the rear cover 2, and the rotating portion 102 is fixed to the base 11. The base 11 seals the end of the rotor 5 near the rear cover 2, and the rotating portion 102 is installed within the base 11, saving installation space.

[0047] In this embodiment, the lengths of the first center screw body 611 and the second center screw body 613 are both greater than or equal to the length of the rotor 5 .

[0048] In this embodiment, the linear drive mechanism 100 is applied to the limb joints of the robot to electrically drive the linear actuator, which has a high degree of integration and a simplified process.

[0049] Example 2

[0050] 1 to 5 , the second embodiment has the same basic structure as the first embodiment and produces the same technical effect, with the difference being that in this embodiment, the rolling screw 6 can be a ball screw, and the screw nut 62 includes a second nut body 628, a first threaded ball groove 629 recessed on the inner circumference of the second nut body 628, a second bearing stop 6210 formed on the outer circumference of the second nut body 628, a third mounting groove 6211 recessed inwardly from the end of the second nut body 628 away from the front cover 3, and a plurality of balls 6212 arranged in the first ball groove 629; the second nut body 628 is arranged on the second shaft In the bearing 8, the second bearing stop 6210 abuts against the side of the second bearing 8 near the rear cover 2. The center screw 61 includes a second center screw body 613 disposed in the rotor 5 and a second protruding end 615 extending from one end of the second center screw body 613 near the front cover 3. The outer periphery of the second center screw body 613 is recessed to form a second threaded ball groove 614. The first ball groove 629 and the second ball groove 614 are correspondingly disposed. The balls 6212 are both sandwiched between the first ball groove 629 and the second ball groove 614 to form a rolling connection between the second center screw body 613 and the second nut body 628. The second center screw 61 and the screw nut 62 formed with the ball groove are connected by the ball 6212. During the rotation of the rotor 5, the screw nut 62 is driven to rotate, thereby driving the second center screw 61 to rotate and realize the linear telescopic function.

[0051] In this embodiment, the linear drive mechanism 100 is applied to the limb joints of the robot to electrically drive the linear actuator, which has a high degree of integration and a simplified process.

[0052] Compared with the prior art, the linear drive mechanism of the present invention drives the rotor to rotate within the housing through the stator, a center screw is arranged within the rotor, a screw nut is arranged to extend axially along the rotor, the screw nut is fixed in the second bearing, and the screw nut is rotatably sleeved on the center screw; the rotor includes a hollow rotor body and a boss extending radially and annularly from the end of the rotor body near the front cover, and the end of the rotor body away from the front cover is fixed to the first bearing, so that the boss and the screw nut are integrated into a one-piece structure, and the rotation of the rotor drives the screw nut to rotate, so that the screw nut rotates and drives the center screw to achieve linear telescopic motion; through the installation arrangement of the first bearing and the second bearing, when the rotor rotates, the screw nut does not move axially. The rotor transmits torque to the center screw during the rotation of the screw nut, which is converted into thrust. Because the screw nut is restricted from axial movement, the center screw is pushed axially according to the interaction of forces, thereby achieving the linear drive motion function. At the same time, the rolling screw is sleeved into the inner wall of the rotor, which effectively shortens the length of the screw nut, and the screw nut can be processed independently, simplifying the process. Further save costs and save installation space.

[0053] The above description is only an embodiment of the present invention. It should be pointed out that those skilled in the art can make improvements without departing from the creative concept of the present invention, but these improvements all fall within the scope of protection of the present invention.

Claims

1. A linear drive mechanism, comprising a housing, a front cover and a rear cover respectively fixed to opposite ends of the housing, a stator disposed within the housing, and a hollow rotor disposed within the stator and rotatably connected to the stator; characterized in that, The linear drive mechanism further includes a rolling screw sleeved inside the rotor, a first bearing sleeved on the rotor and fixed to one end of the rear cover, and a second bearing sleeved on the rolling screw and fixed inside the machine housing; The rolling screw includes a central screw disposed on the inner peripheral side of the rotor and passing through the center of the front cover, and a screw nut extending along the axial direction of the rotor. The screw nut is fixed inside the second bearing, sleeved on the central screw and rotatably connected to the central screw; The rotor includes a hollow rotor body and a ring-shaped boss protruding from the outer periphery of the rotor body near the front cover end along the outer periphery of the rotor body. One end of the rotor body away from the front cover is fixed to the first bearing, and the boss is inserted and fixed to one end of the screw nut near the rear cover. The rotation of the rotor drives the screw nut to rotate, so that the screw nut rotates to drive the central screw to achieve linear telescopic movement.

2. The linear drive mechanism according to claim 1, wherein, The rolling screw is a planetary roller screw. The screw nut includes a first nut body having a threaded structure, a first bearing stop formed on the peripheral side of the first nut body, a first annular installation groove and a second annular installation groove respectively recessed from both ends of the inner wall of the first nut body, a first gear ring fixedly arranged in the first installation groove, a second gear ring fixedly arranged in the second installation groove, and a plurality of annular screw columns arranged around the central screw. Both ends of each annular screw column are respectively arranged in the first gear ring and the second gear ring and form a rotational connection; the first nut body is fixed inside the second bearing, and the first bearing stop abuts against the side of the second bearing near the rear cover; the boss is fixedly arranged in the first installation groove and abuts against the first gear ring; The central screw includes a first central screw body disposed inside the rotor and having a threaded structure, and a first extending end extending from one end of the first central screw body near the front cover; the first central screw body meshes with each of the annular screw columns respectively, and each of the annular screw columns meshes with the first nut body, and the first extending end passes through the front cover.

3. The linear drive mechanism according to claim 1, wherein The rolling screw is a ball screw. The screw nut includes a second nut body, a first ball groove in the shape of a thread recessed from the inner peripheral side of the second nut body, a second bearing stop formed on the outer peripheral side of the second nut body, a third installation groove recessed from one end of the second nut body away from the front cover into it, and a plurality of balls arranged in the first ball groove; the second nut body is arranged inside the second bearing, and the second bearing stop abuts against the side of the second bearing near the rear cover; The central lead screw includes a second central lead screw body disposed within the rotor and a second extending end formed by extending from one end of the second central lead screw body close to the front cover; a second ball groove formed in a spiral shape by recessing the outer circumference of the second central lead screw body, the first ball groove and the second ball groove are correspondingly arranged, and the balls are all clamped between the first ball groove and the second ball groove so that the second central lead screw body and the second nut body form a rolling connection.

4. The linear drive mechanism according to claim 1, wherein, The linear drive mechanism further includes a stopper sleeved and fixed on the screw nut, and the stopper abuts against one side of the second bearing close to the front cover.

5. The linear drive mechanism according to claim 1, characterized in that, The diameter of the rotor is smaller than the diameter of the screw nut.

6. The linear drive mechanism according to claim 1, characterized in that, The rotor further includes an iron core sleeved and fixed on the rotor body and a plurality of permanent magnets fixed on the iron core, and each permanent magnet is spaced from the stator.

7. The linear drive mechanism according to claim 1, wherein The linear drive mechanism further includes a position sensor, the position sensor includes a collection part fixed on the rear cover and a rotation part fixed on the rotor, and the collection part and the rotation part are relatively spaced apart.

8. The linear drive mechanism according to claim 1, wherein The motor formed by the stator and the rotor together adopts an 8-pole 9-slot, 10-pole 12-slot structure, or 14-pole 12-slot structure, or 16-pole 12-slot structure.

9. The linear drive mechanism according to claim 7, characterized in that The position sensor is a Hall position sensor, a magnetic encoding position sensor, or an optical encoding position sensor.

10. The linear drive mechanism according to claim 7, characterized in that, The linear drive mechanism further includes a base sleeved and fixed on the rotor close to the rear cover side, and the rotation part is fixed on the base.

11. The linear drive mechanism according to claim 1, characterized in that, The linear drive mechanism further includes a bearing housing, the bearing housing is sleeved and fixed on the first bearing, and the outer peripheral side of the bearing housing is fixedly connected to the inner wall of the housing.

Images