Compact Electric Push Rod

Abstract

The present invention relates to a compact electric push rod, in which a servo motor is connected to a cylinder assembly through a reduction gear box, and the output end of the cylinder assembly is arranged non-coaxially and parallel to the main axis of the cylinder assembly; the cylinder assembly includes a lead screw, a left bearing assembly, a nut assembly, a right bearing assembly, a cylinder, and an ear assembly; the bottom planes of the bearing seats of the left bearing assembly and the right bearing assembly are coplanar and serve as the installation plane of the whole machine; the left end face and the right end face of the cylinder are respectively connected to the right end face and the left end face of the left bearing assembly and the right bearing assembly; the optical axis parts of the left and right ends of the lead screw are respectively connected to the bearings of the left bearing assembly and the right bearing assembly, and the nut assembly is installed on the lead screw shaft to form a spiral transmission pair; the ear assembly forms a sliding pair with the cylinder groove through a guide plate, the ear assembly is fixedly connected to the nut assembly, and the bearing inner hole of the ear assembly is the output end, which runs back and forth along the groove on the cylinder body, so that the installation space and working space of the electric push rod coincide.

Description

Technical Field

[0001] The present invention relates to an electric push rod, in particular to an electric push rod which has limited installation and working space and requires a compact structure and space. Background Art

[0002] Currently, hydraulic cylinders or electric actuators are commonly used in major engineering fields for pushing, pulling, and lifting operations. Hydraulic cylinder technology is mature and reliable, offering advantages such as stable loads, reliable technology, and low costs, making it widely used. However, hydraulic cylinder technology also has certain application disadvantages, such as low control accuracy, complex components, bulky structure, high noise levels, and leakage, which limit its use in applications with demanding requirements.

[0003] In comparison, electric push rods have the advantages of high control accuracy, simple structure, low noise, and reliable operation. Therefore, they are increasingly replacing hydraulic cylinders and being used.

[0004] The existing conventional electric push rod is generally a linear coaxial push-pull structure, that is, the push rod itself and the object being pushed are coaxially "lined up" structure. Figure 1 .

[0005] Although the electric linear actuator of this structure is mature and reliable, the output end and the electric linear actuator itself are arranged in series, so it occupies a large space and will be greatly restricted in occasions where the installation size is limited. Summary of the Invention

[0006] In order to overcome the above problems, the present invention provides a compact electric push rod, the installation space and the working space of which partially overlap, which can solve the problem that the existing electric push rod requires a large space during installation and use, and has a simple structure.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a compact electric push rod, including a servo motor, a reducer, a reduction box and a cylinder assembly, the output end of the servo motor is connected to the input end of the reducer, the output end of the reducer is connected to the input end of the reduction box, the output end of the reduction box is connected to the input end of the cylinder assembly, the output end of the cylinder assembly is arranged non-coaxially and parallel to the main axis of the cylinder assembly; the cylinder assembly includes a screw, a left bearing assembly, a nut assembly, a right bearing assembly, a cylinder, an ear assembly, and the bearing seat of the left bearing assembly and the right bearing assembly The bottom planes are coplanar and serve as the installation plane of the entire machine; the left end face and the right end face of the cylinder body are respectively connected to the right end face and the left end face of the left bearing assembly and the right bearing assembly; the optical axis parts of the left end and the right end of the screw are respectively connected to the bearings of the left bearing assembly and the right bearing assembly, and the nut assembly is installed on the screw shaft to form a spiral transmission pair; the ear assembly forms a sliding pair with the cylinder body groove through the guide plate, and the ear assembly is fixedly connected to the nut assembly. The inner hole of the bearing of the ear assembly is the output end, and it runs back and forth along the groove on the cylinder body, so that the installation space and working space of the electric push rod coincide.

[0008] Furthermore, the nut assembly includes a left flange, a left wear-resistant ring, a nut, a nut sleeve, a right wear-resistant ring and a right flange. After the left end of the nut is threadedly connected to the left flange, it is inserted into the left hole of the nut sleeve and the end faces are fitted and fixed; the left wear-resistant ring and the right wear-resistant ring are respectively installed at the two ends of the outer cylindrical surface of the nut, and the outer cylindrical surfaces of the left wear-resistant ring and the right wear-resistant ring are matched with the inner hole of the cylinder body for guidance; the right flange is fixed to the right side of the nut, and together with the left flange, the right wear-resistant ring and the left wear-resistant ring are axially limited to prevent them from slipping from the mounting surface of the nut.

[0009] Furthermore, a seal is connected between the ear assembly and the cylinder body to seal and protect the inner cavity of the cylinder body assembly.

[0010] Furthermore, the left bearing assembly includes a bearing, a bearing seat, a bearing end cover, a bearing oil seal, a bearing retaining ring, a bearing retaining ring, a locking nut and a left buffer pad; the bearing, bearing retaining ring, bearing retaining ring, bearing oil seal, bearing end cover and locking nut are integrally installed in the inner hole of the bearing seat; the inner hole of the bearing is interference-connected with the screw optical axis, the bearing retaining ring and the inner hole of the bearing retaining ring are gap-connected with the screw optical axis, and the locking nut cooperates with the screw thread to lock the bearing; the outer ring of the bearing is transition-fitted with the inner hole of the bearing seat.

[0011] Furthermore, the left buffer pad is mounted and fixed on the end face of the bearing seat. When the nut assembly and the left bearing assembly are about to have a mechanical collision, the buffer pad mechanically buffers the collision.

[0012] Furthermore, the right bearing assembly includes a bearing, a bearing seat and a right buffer pad. The bearing is installed in the inner hole of the bearing seat, and the right buffer pad is installed and fixed on the end face of the bearing seat. When the nut assembly and the right bearing assembly are about to have a mechanical collision, the right buffer pad mechanically buffers the collision.

[0013] Furthermore, the ear assembly includes: an ear, a joint bearing, a guide plate and a bearing retaining ring; the ear is provided with a positioning cylindrical surface, and the positioning cylindrical surface is connected to the nut assembly; the upper and lower planes of the ear are installed to fix the guide plate, forming a sliding pair with the slide groove of the cylinder body; the joint bearing is installed in the bearing hole of the ear, and is axially installed and fixed by the bearing retaining ring.

[0014] The beneficial results of the present invention are:

[0015] The present invention partially overlaps the installation space and the working space, thereby achieving a larger stroke of work in a limited installation space.

[0016] In the present invention, the servo motor, the cylinder assembly and the output end are arranged in parallel but not in the same axis, thereby achieving a compact structural design and greatly saving the space of the push rod.

[0017] In the present invention, most of its structure is fixed, static and closed, and only the output end is partially exposed, so it is safer and more reliable. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the existing conventional electric linear actuator structure;

[0019] Figure 2 This is a schematic diagram of the compact electric push rod structure of the present invention;

[0020] Figure 3 It is a schematic diagram of the reduction gearbox of the present invention;

[0021] Figure 4 It is a schematic diagram of the cylinder assembly of the present invention;

[0022] Figure 5 It is a schematic diagram of the cylinder assembly of the present invention;

[0023] Figure 6 is a schematic diagram of the left bearing assembly of the cylinder assembly of the present invention;

[0024] Figure 7 is a schematic diagram of a nut assembly of a cylinder assembly in the present invention;

[0025] Figure 8 is a schematic diagram of the right bearing assembly of the cylinder assembly of the present invention;

[0026] Figure 9 is a schematic diagram of the lug assembly of the cylinder assembly of the present invention;

[0027] Figure 10 It is a schematic diagram of the ear assembly of the cylinder assembly in the present invention.

[0028] In the figure, servo motor 1, reducer 2, reduction gear box 3, cylinder assembly 4, box 31, cover 32, driving wheel 33, driving wheel baffle 34, driven wheel 35, driven wheel baffle 36, transmission belt 37, screw 41, left bearing assembly 42, nut assembly 43, right bearing assembly 44, cylinder 45, ear assembly 46, seal 47, bearing 421, bearing seat 422, bearing end cover 423, bearing oil seal 424, bearing retaining ring 425, bearing retaining ring 426, locking nut 427, left buffer pad 428, left flange 431, left wear-resistant ring 432, nut 433, nut sleeve 434, right wear-resistant ring 435, right flange 436, bearing 441, bearing seat 442, right buffer pad 443, ear piece 461, spherical bearing 462, guide piece 463, bearing retaining ring 464. DETAILED DESCRIPTION

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0030] like Figure 2 As shown, the compact electric push rod of the present invention includes a servo motor 1, a reducer 2, a reduction gear box 3 and a cylinder assembly 4.

[0031] The output of servo motor 1 is connected to the input of reducer 2, with the output of servo motor 1 facing the input of reducer 2. Reducer 2 is arranged in the same axial direction as servo motor 1, and the output of reducer 2 is coaxially connected to the input of reduction gearbox 3. The output of reduction gearbox 3 is coaxially connected to the input of cylinder assembly 4, and the output of cylinder assembly 4 is parallel to its main axis but not coaxially arranged.

[0032] In normal working process, the servo motor 1 outputs a certain torque and speed, which is converted into the required torque and speed through the reducer 2 and the reduction box 3 and serves as the input of the cylinder assembly 4. After receiving the torque and speed, the cylinder assembly 4 converts it into the final push-pull force and linear velocity for output.

[0033] like Figure 3 As shown, the reduction gear box 3 includes a box body 31 , a cover plate 32 , a driving wheel 33 , a driving wheel baffle 34 , a driven wheel 35 , a driven wheel baffle 36 and a transmission belt 37 .

[0034] The housing 31 and the cover plate 32 are connected to form a sealed cavity, which contains a transmission gear train (mainly composed of a driving wheel 33, a driven wheel 35 and a transmission belt 37). The driving wheel 33 is connected to the output end of the reducer 2 as the input end of the reduction housing 3, and the driving wheel baffle 34 axially fixes the connection; the driven wheel 35 is connected to the input end of the cylinder assembly 4 as the output end of the reduction housing 3, and the driven wheel baffle 36 axially fixes the connection; the transmission belt 37 is the transmission connection hub between the driving wheel 33 and the driven wheel 35.

[0035] like Figure 4 As shown in FIG5 , the cylinder assembly 4 includes a lead screw 41 , a left bearing assembly 42 , a nut assembly 43 , a right bearing assembly 44 , a cylinder 45 , an ear assembly 46 and a seal 47 .

[0036] The cylinder assembly 4 mainly converts the input torque and speed into push-pull force and linear velocity through the screw 41. However, due to the sensitivity of the screw drive to the turning torque and radial force, it must overcome the turning torque and radial force generated by the output end load on the screw drive. In this embodiment, the support guide on the nut assembly 43 (left wear-resistant ring 432, right wear-resistant ring 435, see Figure 6 ) generates an equal and opposite turning torque on the nut 433 to balance the turning torque.

[0037] When the screw of the cylinder assembly 4 is driven, the nut 433 generates a circumferential force that must be balanced to prevent the nut 433 from rotating, thereby ensuring stable output of the electric push rod. In this embodiment, the lug assembly 46 and the guide groove of the cylinder 45 generate circumferential forces of equal magnitude and opposite directions to balance the circumferential force.

[0038] The bottom surfaces of the bearing seats of the left and right bearing assemblies 42 and 44 are coplanar and serve as the mounting surface for the entire machine. The left and right end faces of the cylinder block 45 are connected to the left and right end faces of the left and right bearing assemblies 42 and 44, respectively. The lug assembly 46 forms a sliding pair with the guide plate 463 and the slideway of the cylinder block 45. Seals 47 are connected to the lug assembly 46 and cylinder block 45, respectively, to provide sealing protection for the cylinder block assembly's interior. The optical axis at the left and right ends of the lead screw 41 is connected to the bearings of the left and right bearing assemblies 42 and 44, respectively. The nut assembly 43 is mounted on the shaft of the lead screw 41, forming a helical transmission pair.

[0039] like Figure 6 As shown, the left bearing assembly 42 includes a bearing 421, a bearing seat 422, a bearing end cover 423, a bearing oil seal 424, a bearing retaining ring 425, a bearing retaining ring 426, a locking nut 427 and a left buffer pad 428.

[0040] The bearing 421, the bearing retaining ring 425, the bearing retaining ring 426, the bearing oil seal 424, the bearing end cover 423 and the locking nut 427 are integrally installed in the inner hole of the bearing seat 422; the inner hole of the bearing 421 is interference-connected with the optical axis of the screw 41, the inner holes of the bearing retaining ring 425 and the bearing retaining ring 426 are gap-connected with the optical axis of the screw 41, and the locking nut 427 cooperates with the thread of the screw 41 to lock the bearing 421; the outer ring of the bearing 421 is installed with a transition fit with the inner hole of the bearing seat 422; the left buffer pad 428 is installed and fixed on the end face of the bearing seat 422, and when the nut assembly 43 and the left bearing assembly 42 are about to have a mechanical collision, the left buffer pad 428 mechanically buffers the collision.

[0041] like Figure 7 As shown, the nut assembly 43 includes a left flange 431 , a left wear-resistant ring 432 , a nut 433 , a nut sleeve 434 , a right wear-resistant ring 435 and a right flange 436 .

[0042] After the left end of the nut 433 is threadedly connected to the left flange 431, it is inserted into the left hole of the nut sleeve 434 and the end faces are fitted and fixed; the left wear-resistant ring 432 and the right wear-resistant ring 435 are respectively installed on the two ends of the outer cylindrical surface of the nut 434, and their outer cylindrical surfaces are matched with the inner hole of the cylinder body 45 to form a guide; the right flange 436 is fixed to the right side of the nut 433, and it and the left flange 431 respectively limit the axial position of the right wear-resistant ring 435 and the left wear-resistant ring 432 to prevent them from slipping from the mounting surface of the nut 433.

[0043] like Figure 8 As shown, the right bearing assembly 44 includes a bearing 441, a bearing seat 442, and a right buffer pad 443. The bearing 441 is installed in the inner hole of the bearing seat 442, and the right buffer pad 443 is fixed to the end surface of the bearing seat 442. When the nut assembly 43 and the right bearing assembly 44 are about to mechanically collide, the right buffer pad 442 mechanically cushions the collision.

[0044] like Figure 9 As shown in FIG10 , the lug assembly 46 includes a lug 461, a spherical bearing 462, a guide piece 463, and a bearing retaining ring 464. A positioning cylindrical surface is designed at the end of the lug 461, which is engaged with the corresponding positioning cylindrical hole of the nut assembly 43; the upper and lower surfaces of the lug 461 are fixedly mounted on the guide piece 463, forming a sliding pair with the slide groove of the cylinder body 45; the spherical bearing 462 is installed in the bearing hole of the lug 461 and is axially fixed by the bearing retaining ring 464.

Claims

1. A compact electric push rod, comprising a servo motor (1), a reducer (2), a reduction gear box (3) and a cylinder assembly (4), characterized in that: The output end of the servo motor (1) is connected to the input end of the reducer (2), the output end of the reducer (2) is connected to the input end of the reduction gear box (3), the output end of the reduction gear box (3) is connected to the input end of the cylinder assembly (4), and the output end of the cylinder assembly (4) is arranged non-coaxially and parallel to the main axis of the cylinder assembly (4); the cylinder assembly (4) includes a lead screw (41), a left bearing assembly (42), a nut assembly (43), a right bearing assembly (44), a cylinder (45), and an ear assembly (46); the bottom planes of the bearing seats of the left bearing assembly (42) and the right bearing assembly (44) are coplanar and serve as the installation plane of the entire machine; the left end of the cylinder (45) is parallel to the main axis of the cylinder assembly (4). The left and right end faces of the lead screw (41) are connected to the right and left end faces of the left bearing assembly (42) and the right bearing assembly (44), respectively; the optical axis portions of the left and right ends of the lead screw (41) are connected to the bearings of the left bearing assembly (42) and the right bearing assembly (44), respectively; the nut assembly (43) is mounted on the lead screw (41) shaft to form a spiral transmission pair; the lug assembly (46) forms a sliding pair with the slide groove of the cylinder body (45) through the guide piece (463); the lug assembly (46) is fixedly connected to the nut assembly (43); the inner hole of the bearing of the lug assembly (46) is the output end, and it runs back and forth along the slide groove on the cylinder body (45), so that the installation space and the working space of the electric push rod coincide with each other; The ear assembly (46) includes: an ear (461), a joint bearing (462), a guide piece (463) and a bearing retaining ring (464); the ear (461) is provided with a positioning cylindrical surface, and the positioning cylindrical surface is connected to the nut assembly (43); the upper and lower surfaces of the ear (461) are fixedly mounted on the guide piece (463), forming a sliding pair with the slide groove of the cylinder body (45); the joint bearing (462) is mounted in the bearing hole of the ear (461) and is axially mounted and fixed by the bearing retaining ring (464); the nut assembly (43) includes a left flange (431), a left wear-resistant ring (432), a nut (433), a nut sleeve (434), a right wear-resistant ring (435) and right flange (436), after the left end of the nut (433) is threadedly connected to the left flange (431), it is inserted into the left hole of the nut sleeve (434) and the end faces are fixed; the left wear-resistant ring (432) and the right wear-resistant ring (435) are respectively installed on the two ends of the outer cylindrical surface of the nut sleeve (434), and the outer cylindrical surfaces of the left wear-resistant ring (432) and the right wear-resistant ring (435) are matched with the inner hole of the cylinder body (45) for guidance; the right flange (436) is fixed to the right side of the nut (433), and together with the left flange (431), the right wear-resistant ring (435) and the left wear-resistant ring (432) are axially limited to prevent them from sliding off the mounting surface of the nut (433).

2. The compact electric linear actuator according to claim 1, characterized in that: A sealing member (47) is also connected between the ear assembly (46) and the cylinder body (45) to seal and protect the inner cavity of the cylinder body assembly.

3. The compact electric linear actuator according to claim 1, characterized in that: The left bearing assembly (42) includes a bearing (421), a bearing seat (422), a bearing end cover (423), a bearing oil seal (424), a first bearing retaining ring (425), a second bearing retaining ring (426), a locking nut (427) and a left buffer pad (428); the bearing (421), the first bearing retaining ring (425), the second bearing retaining ring (426), the bearing oil seal (424), the bearing end cover (423) and the locking nut (427) are integrally installed in the inner hole of the bearing seat (422); the inner hole of the bearing (421) is interference-connected with the optical axis of the screw (41), the inner holes of the first bearing retaining ring (425) and the second bearing retaining ring (426) are gap-connected with the optical axis of the screw (41), and the locking nut (427) cooperates with the thread of the screw (41) to lock the bearing (421); the outer ring of the bearing (421) is transition-fitted with the inner hole of the bearing seat (422).

4. The compact electric linear actuator according to claim 3, characterized in that: The left buffer pad (428) is mounted and fixed on the end surface of the bearing seat (422). When the nut assembly (43) and the left bearing assembly (42) are about to mechanically collide, the buffer pad (428) mechanically buffers the collision.

5. The compact electric linear actuator according to claim 1, characterized in that: The right bearing assembly (44) includes a second bearing (441), a second bearing seat (442) and a right buffer pad (443), wherein the second bearing (441) is installed in the inner hole of the second bearing seat (442), and the right buffer pad (443) is installed and fixed on the end surface of the second bearing seat (442). When the nut assembly (43) and the right bearing assembly (44) are about to mechanically collide, the right buffer pad (443) mechanically buffers the collision.

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