Electric cylinder for engineering machines with nut with bumper

Abstract

The application discloses a nut buffer type electric cylinder for engineering machinery, which comprises a push rod, one end of which is connected with a load and the other end of which is axially movable in a cylinder barrel, and the other end of the push rod is provided with a containing cavity; a screw rod coaxially penetrating through the containing cavity and arranged in the push rod; a nut arranged in the containing cavity and matched with the screw rod in a threaded mode; and a buffer spring set, two ends of which are respectively abutted against the nut and the side wall of the containing cavity and arranged in the containing cavity. The application has the characteristics of reducing impact and prolonging service life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric cylinders, and more particularly, to an electric cylinder with a nut buffer for engineering machinery. BACKGROUND

[0002] The electric cylinder is a new revolutionary product for realizing high-precision linear motion series by converting the rotary motion of a motor into linear motion and converting the accurate speed control, accurate number of revolutions control and accurate torque control of the motor into accurate speed control, accurate position control and accurate thrust control. At present, the traditional electric cylinder structure does not have a buffer structure. For the electric cylinder used on engineering machinery such as excavators and bulldozers, the electric cylinder often bears impact load. The impact load will cause the screw rod and the nut to bear periodic pulsating load, which will greatly reduce the service life of the electric cylinder.

[0003] Therefore, it is necessary to design an electric cylinder with a buffer structure. SUMMARY

[0004] The present application discloses an electric cylinder with a nut buffer for engineering machinery. The nut is buffered by a buffer spring set, thereby reducing the impact of external impact load on the electric cylinder and prolonging the service life.

[0005] The technical scheme provided by the present application is as follows:

[0006] An electric cylinder with a nut buffer for engineering machinery comprises:

[0007] a push rod, one end of which is connected to a load and the other end of which is axially movable in a cylinder barrel, and the other end of the push rod is provided with a containing cavity; and

[0008] a screw rod, which is coaxially arranged in the containing cavity and in the push rod;

[0009] a nut, which is arranged in the containing cavity and is threadedly matched with the screw rod;

[0010] a first buffer spring set, both ends of which are respectively abutted against the nut and the side wall of the containing cavity and arranged in the containing cavity.

[0011] Preferably, the electric cylinder further comprises:

[0012] the other end of the push rod is a compression nut, which is used to form the containing cavity;

[0013] a second buffer spring set, which is arranged between the nut and the compression nut.

[0014] Preferably, the electric cylinder further comprises:

[0015] a motor; and

[0016] a planetary reducer, an input end of which is connected with an output end of the motor;

[0017] a reduction box, an input end of which is connected with an output end of the planetary reducer;

[0018] a cylinder, which is fixed on the left side of the reduction box.

[0019] Preferably, the reduction box further comprises:

[0020] a driving wheel, which is fixed on the output end of the planetary reducer;

[0021] an idler wheel, which is in mesh with the driving wheel;

[0022] a driven wheel, which is in mesh with the idler wheel, and the driven wheel is fixed on the other end of the screw rod;

[0023] wherein the driving wheel, the idler wheel and the driven wheel are rotatably arranged in the gear box.

[0024] Preferably, the gear box further comprises:

[0025] a bearing chamber, which is a cylindrical structure with both ends open, and one end of the bearing chamber is fixed on the left side of the gear box;

[0026] a main bearing, which is arranged in the bearing chamber;

[0027] a main bearing pressing sleeve, one end of which is clamped on the left side of the gear box, and the other end of which is clamped on the outer ring on one side of the main bearing;

[0028] a bearing nut, which is detachably fixed on the screw rod, and the bearing nut is clamped on the inner ring on one side of the main bearing.

[0029] Preferably, the gear box further comprises:

[0030] a flange, which is arranged in the middle of the screw rod, and the flange is clamped on the other side of the main bearing.

[0031] Preferably, the gear box further comprises:

[0032] a front end joint, which is fixed on one end of the push rod;

[0033] a front end cover, which is fixed on one end of the cylinder;

[0034] a push rod guide bearing, which is fixed in the front end cover, and the push rod guide bearing is sleeved on the outside of the push rod;

[0035] a dustproof ring, which is fixed in the front end cover, and the dustproof ring is sleeved on the outside of the push rod;

[0036] A waterproof sealing ring is fixed in the front end cover, and the dustproof ring is sleeved outside the push rod.

[0037] Wherein, the other end of the cylinder is fixed in one end of the bearing chamber.

[0038] Preferably, further comprising:

[0039] A plurality of electric cylinder mechanical limiting blocks are respectively arranged on the opposite sides of the front end cover and the bearing chamber, and are used for blocking and limiting the accommodating cavity of the push rod.

[0040] Preferably, further comprising:

[0041] A guide groove is arranged in the cylinder along the axial direction of the cylinder;

[0042] A rotation stopping key is fixed outside the other end of the push rod, and the rotation stopping key is axially movable and engaged in the guide groove;

[0043] A groove is axially arranged inside the accommodating cavity;

[0044] An inner rotation stopping key is fixed on the nut, and the inner rotation stopping key is axially movable and engaged in the groove.

[0045] Preferably, further comprising:

[0046] A lower supporting ear is integrally formed outside the gear box cover.

[0047] The beneficial effects of the present application are:

[0048] The nut with buffer of the electric cylinder for engineering machinery provided by the present application greatly reduces the impact of external impact load on the electric cylinder, so that the electric cylinder can be buffered in time when encountering harsh working conditions in engineering operation, greatly prolonging the service life of the electric cylinder, and the electric cylinder drive adopts gear transmission, and the rigidity is better. BRIEF DESCRIPTION OF DRAWINGS

[0049] Figure 1 The structure diagram of the nut with buffer of the electric cylinder for engineering machinery is shown.

[0050] Figure 2 The cross-sectional structure diagram of the lower supporting ear is shown. DETAILED DESCRIPTION

[0051] The present application will be further described in detail below, so that those skilled in the art can implement it according to the description.

[0052] As Figure 1 shown, the present application provides a nut with buffer of the electric cylinder for engineering machinery, comprising:

[0053] Front end joint 1, power end, reduction box, bearing chamber 12, cylinder 9, push rod 2, screw rod 34, nut 28, compression nut 25 and buffer spring group.

[0054] The power end comprises a motor 22 and a planetary reducer 21, the motor 22 converts electrical energy into mechanical energy, the output end of the motor 22 is connected with the input end of the planetary reducer 21, and the planetary reducer 21 is used for reducing speed and increasing torque of the motor 22; the reduction box comprises a gear box 14, a gear box cover 16, a driving wheel 20, an idler wheel 19 and a driven wheel 18, the gear box 14 is a "N" type structure; the gear box cover 16 is fixed on the right side of the gear box 14 through detachable screws 15 and is used for sealing the gear box 14; the driving wheel 20, the idler wheel 19 and the driven wheel 18 are all gear structures, the driving wheel 20 and the idler wheel 19 are rotatably arranged in the gear box 14 through auxiliary bearings 17, the auxiliary bearings 17 are all used for positioning and supporting, the idler wheel 19 is arranged between the driving wheel 20 and the driven wheel 18 and is in mesh with the driving wheel 20 and the driven wheel 18; the planetary reducer 21 is fixed at the bottom of the gear box 14, and the driving wheel 20 is connected with the output shaft of the planetary reducer through a flat key, so as to transmit the movement and power of the planetary reducer 21 to the electric cylinder.

[0055] In the embodiment, the motor 22 can be a three-phase alternating current motor, a servo motor or a direct current motor.

[0056] The bearing chamber 12 comprises a main bearing 11, a main bearing pressing sleeve 13 and a bearing nut 24, the bearing chamber 12 is a cylindrical structure with both ends being open, one end of the bearing chamber is arranged on the left side of the gear box 14 corresponding to the position of the driven wheel 18 and is used for supporting the main bearing 11; the main bearing 11 is arranged in the bearing chamber 12 and is used for bearing external load thrust or tension; one end of the main bearing pressing sleeve 13 is clamped on the left side of the gear box 14, the other end is clamped on the outer ring of one side of the main bearing 11 and is used for positioning the outer ring of the main bearing 11; the bearing nut 24 is coaxially arranged in the inside of the main bearing pressing sleeve 13, and the bearing nut 24 is clamped on the inner ring of one side of the main bearing 11 and is used for fixing the inner ring of the main bearing 11.

[0057] In the embodiment, the bearing nut 24 is screwed on the screw rod 34 through threads.

[0058] The cylinder 9 is fixed at the other end of the bearing chamber 12, for sealing the lead screw 34 and the push rod 2, preventing external impurities from entering the electric cylinder, and preventing the rotating lead screw 34 from hurting people; the push rod 2 is a hollow steel structure, and one end of the push rod 2 is connected with the front end joint 1, the front end joint 1 is connected with the load, and the other end of the push rod 2 is coaxially arranged in the cylinder 9 and is axially movable, and the other end of the push rod 2 is provided with a containing cavity; one end of the lead screw 34 is coaxially arranged in the push rod 2 through the lead screw guide bearing 30, and the lead screw guide bearing 30 is fixed through the collar 32; the middle part of the lead screw 34 is provided with a flange structure, the flange structure is clamped on the other side of the main bearing 11, the other end of the lead screw 34 is rotatably arranged through the main bearing 11, the bearing nut 24, and then connected with the driven wheel 18 through the flat key 33, and finally rotatably arranged in the gear box 14 through the auxiliary bearing 17; the nut 28 is arranged on the lead screw 34 and is axially movable, for converting the rotary motion of the lead screw 34 into the linear motion of the nut 28, the nut 28 is arranged in the containing cavity of the push rod 2 and is axially movable, the compression nut 25 is screwed on the right end of the push rod 2 through threads, for forming a buffer spring set containing cavity; the buffer spring set includes a left buffer spring set 29 and a right buffer spring set 26, the left buffer spring set 29 and the right buffer spring set 26 are sleeved on the outside of the lead screw 34, the left buffer spring set 29 is compressed between the nut 28 and the push rod 2, and the right buffer spring set 26 is compressed between the nut 28 and the compression nut 25.

[0059] In the embodiment, the front end joint 1 is an external thread joint, and as preferred, other joints such as a pin end, a rod end joint bearing, etc. can also be used.

[0060] In the embodiment, the lead screw 34 and the gear box 14 are separated by the oil seal 23, so that the oil in the cylinder body and the oil in the gear box 14 are lubricated separately.

[0061] In the embodiment, the lead screw 34 can be a trapezoidal lead screw, a ball lead screw, a planetary roller lead screw, or a rectangular thread lead screw, and correspondingly, the nut 28 can be a trapezoidal nut, a ball nut, a planetary roller nut, or a rectangular thread nut.

[0062] The inner side of the cylinder 9 is provided with a guide groove 7 along the axial direction. An anti-rotation key 10 is fixed on the outer side of the other end of the push rod 2. The anti-rotation key 10 is axially movable and engaged in the guide groove 7, so that the anti-rotation key 10 can move along the guide groove 7 to prevent the push rod 2 from rotating, so that the push rod 2 can only move in a straight line. An oil nozzle 8 is also provided on the cylinder 9 to facilitate the maintenance and lubrication of the electric cylinder. A groove 36 is provided axially inside the receiving cavity. An inner anti-rotation key 27 is provided on the outer side of the nut 28. The inner anti-rotation key 27 is axially movable and engaged in the groove 36 to prevent the nut 28 from rotating.

[0063] A front cover 5 is connected to one end of the cylinder 9 by screws for installing a dustproof ring 3, a waterproof sealing ring 4, and a push rod guide bearing 37. An O-ring 6 is provided between the cylinder 9 and the front cover 5 to seal the entire electric cylinder and improve its protection level. The dustproof ring 3, the waterproof sealing ring 4, and the push rod guide bearing 37 are arranged sequentially from one end of the push rod to the other, spaced apart between the push rod 2 and the front cover 5. The dustproof ring 3 prevents external dust from entering the electric cylinder, keeping the inside of the electric cylinder clean. The entry of impurities may cause rapid wear of the lead screw 34 and the nut 28, leading to the failure of the electric cylinder. The waterproof sealing ring 4 prevents external moisture from entering the electric cylinder, preventing the grease inside the electric cylinder from being contaminated by water. The push rod guide bearing 37 guides the push rod 2, making its movement more stable.

[0064] The other end of the cylinder 9 is fixed to one end of the bearing chamber 12.

[0065] In this embodiment, the push rod guide bearing 37 is made of a self-lubricating material.

[0066] like Figure 2 As shown, in this embodiment, a lower support lug 35 is formed on the outer side of the gearbox cover 16 for fixing the electric cylinder to external machinery.

[0067] Two mechanical limit blocks 38 for electric cylinders are respectively provided on the opposite side of the front cover 5 and the bearing chamber 12. When the electric cylinder runs over-travel, it can block and limit the electric cylinder, thereby reducing the impact of over-travel on the electric cylinder.

[0068] In this embodiment, the material of the electric cylinder mechanical limit block 38 is polyurethane rubber.

[0069] The working process of this invention is as follows:

[0070] When the motor 22 is energized, the output shaft of the motor 22 rotates and transmits the motion to the planetary reducer 21 through a hoop or a key, the output shaft of the planetary reducer 21 starts to rotate, and then drives the driving gear 20 to rotate through the key on the output shaft. The driving gear 20 transmits the motion to the driven gear 18 through the idler gear 19, and the driven gear 18 transmits the motion to the lead screw 34 through the key 33, the lead screw 34 rotates, and the nut 28 converts the rotary motion of the lead screw 34 into linear motion, and then drives the push rod 2 to move linearly.

[0071] When the electric cylinder is subjected to tension, the push rod 2 has a tendency to move to the left, which drives the compression nut 25 to compress the right buffer spring set 26, the right buffer spring set 26 buffers the load and then transmits the load to the nut 28, the nut 28 transmits the load to the lead screw 34, and then transmits the load to the gear box 14 and the gear box cover 16 through the main bearing 11, and finally unloads the force through the lower supporting ear 35.

[0072] When the electric cylinder is subjected to tension, the push rod 2 has a tendency to move to the left, which drives the compression nut 25 to compress the right buffer spring set 26, the right buffer spring set 26 buffers the load and then transmits the load to the nut 28, the nut 28 transmits the load to the lead screw 34, and then transmits the load to the gear box 14 and the gear box cover 16 through the main bearing 11, and finally unloads the force through the lower supporting ear 35.

[0073] The nut buffer electric cylinder for engineering machinery provided by the application adopts a new type of gear electric cylinder, buffer spring sets are installed on the left and right sides of the nut, so that the electric cylinder can be buffered in time when encountering severe working conditions in engineering operation, the impact of external impact load on the electric cylinder is greatly reduced, the service life of the electric cylinder is greatly prolonged, and the electric cylinder drive adopts gear transmission, and the rigidity is better.

[0074] Although the embodiments of the application have been disclosed as above, they are not limited to the applications listed in the specification and the embodiments, and can be fully applied to various fields suitable for the application, and additional modifications can be easily realized by those skilled in the art, therefore, the application is not limited to specific details and the embodiments shown and described herein, without departing from the general concept defined by the claims and the equivalent scope.

Claims

1. An electric cylinder for construction machines with a nut buffer, characterized by, The utility model relates to a kind of electric cylinder, including: Push rod, one end can be connected with load, the other end can be moved axially in cylinder barrel, and the other end of the push rod is provided with accommodating cavity; And Lead screw, coaxially through the accommodating cavity and be provided in the push rod; Nut, it is arranged in the accommodating cavity, and with the lead screw screw thread matches; First buffer spring group, two ends respectively abut against nut and the lateral wall of accommodating cavity and is arranged in the accommodating cavity; The other end of the push rod is compression nut, for forming the accommodating cavity; Second buffer spring group, it is arranged between the nut and compression nut; Motor; Planetary reducer, input end is connected with the output end of motor; Speed reducer box, input end is connected with the output end of the planetary reducer; Cylinder barrel, it is fixed in the left side of the speed reducer box; Bearing chamber, it is the cylindrical structure of two ends opening, and one end of the bearing chamber is fixed in the left side of gear box; Front end cover, it is fixed in one end of the cylinder barrel; Multiple electric cylinder mechanical limit block, it is respectively arranged on the opposite side of the front end cover and bearing chamber, for blocking and limiting the accommodating cavity of the push rod; The material of the electric cylinder mechanical limit block is polyurethane rubber material.

2. The nut-buffered electro-hydraulic cylinder for construction machines according to claim 1, characterized by The speed reducer box further includes: Driving wheel, it is fixed in the output end of the planetary reducer; Idler, it is engaged with the driving wheel; Driven wheel, it is engaged with the idler, and the driven wheel is fixed in the other end of the lead screw; Wherein, the driving wheel, idler, driven wheel can be rotatably arranged in gear box.

3. The nut-buffered electro-hydraulic cylinder for construction machines according to claim 2, characterized by Further including: Main bearing, it is arranged in the bearing chamber; Main bearing pressing sleeve, one end is engaged in the left side of the gear box, the other end is engaged in the outer ring of one side of the main bearing; Bearing nut, it is detachably fixed on the lead screw, and the bearing nut is engaged in the inner ring of one side of the main bearing.

4. The nut-buffered electro-hydraulic cylinder for construction machines according to claim 3, characterized by Further including: Flange, it is arranged in the middle of the lead screw, and the flange is engaged in the other side of the main bearing.

5. The nut-buffered electro-hydraulic cylinder for construction machines according to claim 4, characterized by Further including: Front end connector, it is fixed in one end of the push rod; Push rod guide bearing, it is fixed in the front end cover, and the push rod guide bearing is sleeved on the outside of the push rod; Dustproof ring, it is fixed in the front end cover, and the dustproof ring is sleeved on the outside of the push rod; Waterproof sealing ring, it is fixed in the front end cover, and the dustproof ring is sleeved on the outside of the push rod; Wherein, the other end of the cylinder barrel is fixed in one end of the bearing chamber.

6. The nut-buffered electro-hydraulic cylinder for construction machines according to claim 5, wherein Further including: Guide groove, it is arranged in the cylinder barrel along the axial direction of the cylinder barrel; Anti-rotation key, it is fixed on one end of the push rod, and the anti-rotation key is axially movable and engaged in the guide groove; Groove, it is axially arranged on the inside of the accommodating cavity; Inner anti-rotation key, it is fixed on the nut, and the inner anti-rotation key is axially movable and engaged in the groove.

7. The cushioned nut electric cylinder for construction machines according to claim 6, wherein Further including: Lower supporting lug, it is integrally formed on the outside of the gear box cover; Wherein, the gear box cover is fixed on the right side of the gear box through detachable screw.

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