Screw rod drive is oil jack in pit
阅读说明：本技术 一种螺杆驱动井下抽油装置 (Screw rod drive is oil jack in pit ) 是由 林海瑞 付建红 苏昱 *** 吴鹏程 于 2019-10-28 设计创作，主要内容包括：本发明涉及一种螺杆驱动井下抽油装置,包括下端盖、换向组件、连接筒Ⅰ、连接筒Ⅱ、连接套筒、滚动螺旋副、上端盖、往复杆、上接头套管、螺母接头、接杆、拉杆；所述拉杆一端与滚动螺旋副连接,另一端分别与下压环、上回程环连接,所述输出轴通过连接套筒与滚动螺旋副连接,所述往复杆位于滚动螺旋副内,另一端位于上接头套管内并通过螺母接头与接杆连接；所述下端盖、连接筒Ⅰ、连接筒Ⅱ、滚动螺旋副、上端盖、上接头套管依次连接。本发明由旋转动力输入,螺杆输出往复运动带动抽油泵采油；相较于其它结构形式的采油机,螺杆驱动采油占有空间相对较小,而且滚珠螺杆或者静压螺杆的传动效率相对较高。(The invention relates to a screw-driven underground oil pumping device which comprises a lower end cover, a reversing assembly, a connecting cylinder I, a connecting cylinder II, a connecting sleeve, a rolling screw pair, an upper end cover, a reciprocating rod, an upper joint sleeve, a nut joint, a connecting rod and a pull rod, wherein the lower end cover is connected with the reversing assembly; one end of the pull rod is connected with the rolling screw pair, the other end of the pull rod is respectively connected with the lower compression ring and the upper return ring, the output shaft is connected with the rolling screw pair through a connecting sleeve, the reciprocating rod is positioned in the rolling screw pair, and the other end of the reciprocating rod is positioned in the upper joint sleeve and is connected with the connecting rod through a nut joint; the lower end cover, the connecting cylinder I, the connecting cylinder II, the rolling spiral pair, the upper end cover and the upper joint sleeve are sequentially connected. The invention inputs rotary power, the screw outputs reciprocating motion to drive the oil pump to extract oil; compared with oil extraction machines with other structural forms, the screw-driven oil extraction machine has the advantages that the occupied space for oil extraction is relatively small, and the transmission efficiency of the ball screw or the static pressure screw is relatively high.)
1. A screw rod driving downhole oil pumping device is characterized by comprising a lower end cover (55), a reversing assembly, a connecting cylinder I (21), a connecting cylinder II (24), a connecting sleeve (19), a rolling screw pair, an upper end cover (58), a reciprocating rod (59), an upper joint sleeve (60), a nut joint (61), a connecting rod (62), a pull rod (22) and a pressure rod (56);
the reversing assembly comprises a reversing shaft shell (16), a top tail (54), an upper limiting assembly, a stop block (6), a rotary steering assembly, a lower limiting assembly, a top head (36), an input shaft (1) and an output shaft (8) which are sequentially and axially mounted in the reversing shaft shell (16), wherein the top tail (54), the upper limiting assembly and the stop block (6) are sequentially arranged on the input shaft (1), and the lower limiting assembly and the top head (36) are sequentially arranged on the output shaft (8); tapered roller bearings (3) are arranged in the jacking tail (54) and the jacking head (36);
the lower limit component comprises a lower pressing ring, a lower pressing rod (51), a top cylinder, a lower cylindrical bolt spring (52), a lower fixed cylinder ring and a lower return ring (50), wherein the top cylinder, the lower cylindrical bolt spring, the lower fixed cylinder ring and the lower return ring are sleeved on the input shaft (1); the top cylinder, the lower cylindrical bolt spring (52) and the lower return ring (50) are all positioned in the lower fixed cylinder ring; one end of the lower cylindrical bolt spring (52) is propped against the top cylinder, and the other end of the lower cylindrical bolt spring is pressed against the end surface of the top tail (54); the lower return ring (50) is positioned between the top cylinder and the stop block (6); a lower spring and a lower limiting clamp for pressing the lower spring are arranged in the radial groove; one end of the lower pressure rod (51) props against the lower pressure ring, and the other end of the lower pressure rod compresses the lower limit clamp;
the rotary steering assembly comprises a sleeve (44), a transmission cylinder (7), a middle supporting shaft (9), a middle transmission cylinder (10), a radial sliding bearing (47), a lower sliding bearing (49), a lower bevel gear installed in the lower sliding bearing (49), a small bevel gear (46) and an upper bevel gear (45) installed in the upper sliding bearing; the transmission cylinder (7) is sleeved at the end part of the input shaft (1) and is positioned in the lower bevel gear; the end part of the output shaft (8) is sequentially provided with a lower thrust bearing, a lower pressing block, a lower friction plate and a lower transmission plate which are positioned in the lower bevel gear; the middle transmission cylinder (10) is sleeved on the output shaft (8), and an upper friction plate (11), an upper transmission plate (12), an upper pressing block (13) and an upper thrust bearing (14) are sequentially arranged at the position, close to the middle transmission cylinder (10), of the output shaft (8); the middle transmission cylinder (10), the upper friction plate (11), the upper transmission plate (12), the upper pressing block (13) and the upper thrust bearing (14) are all positioned in the upper bevel gear (45); the lower bevel gear, the small bevel gear (46) and the upper bevel gear (45) are sequentially in meshing transmission;
the upper limiting assembly comprises an upper pressing ring (37), an upper pressing rod (39), a pressing cylinder (42) sleeved on the output shaft (8), an upper cylindrical bolt spring, an upper fixing cylinder ring (38) with a radial groove and an upper return ring; the pressing cylinder (42), the upper cylindrical bolt spring and the upper return ring are all positioned in the upper fixed cylinder ring (38); one end of the pressing cylinder (42) presses the upper push bearing (14); one end of the upper cylindrical bolt spring is pressed on the ejector (42), and the other end of the upper cylindrical bolt spring is propped against the bottom end face of the ejector head (36); the upper return ring is positioned between the pressing cylinder (42) and the sleeve (44); an upper spring and an upper limit clamp for pressing the upper spring are arranged in the radial groove; one end of the upper pressure rod (39) props against the upper pressure ring (37), and the other end of the upper pressure rod compresses the upper limit clamp;
the output shaft (8) is connected with the rolling screw pair through a connecting sleeve (19), the reciprocating rod (59) is positioned in the rolling screw pair, and the other end of the reciprocating rod is positioned in an upper joint sleeve (60) and is connected with a connecting rod (62) through a nut joint (61);
one end of the pull rod (22) is connected with the upper part of the rolling screw pair, and the other end of the pull rod is respectively connected with the lower compression ring and the upper return ring; one end of the pressure lever (56) is propped against the lower part of the rolling screw pair, and the other end of the pressure lever is pressed on the lower return ring (50); the upper pressing ring (37) is connected to the middle part of the pressing rod (56); the lower end cover (55), the connecting cylinder I (21), the connecting cylinder II (24), the rolling screw pair, the upper end cover (58) and the upper joint sleeve (60) are sequentially connected.
2. The screw-driven downhole oil pumping device according to claim 1, wherein the lower fixed cylinder ring is internally provided with a lower centering cylinder (53) and a lower centering ring (5).
3. A screw driven downhole oil well pumping apparatus according to claim 2, wherein the upper stationary barrel ring (38) is provided with an upper centering barrel and an upper centering ring (41).
4. The screw-driven downhole pumping unit according to claim 1, wherein the rolling screw pair comprises a housing (30), a rolling screw pair screw (27), a rolling screw pair nut (28), a pressing ring (29) and a pulling ring (57), the pulling ring (57) is connected with the pulling rod (22), and the pressing rod (56) abuts against the pressing ring (29); a tapered roller bearing II (23) is arranged in the connecting cylinder II (24), the rolling screw pair screw (27) penetrates through the tapered roller bearing II (23) and is connected with the output shaft (8) through a connecting sleeve (19), the rolling screw pair nut (28) is connected to the rolling screw pair screw (27), and a steel ball (26) and a ball stopper (25) are arranged on the rolling screw pair screw (27); clamping ring (29), pull ring (57) are installed respectively at the inner chamber both ends of shell (30), reciprocating lever (59) one end with rolling screw pair nut (28) contact, connecting cylinder II (24), shell (30), upper end cover (58) connect gradually.
5. The screw-driven downhole oil well pumping device according to claim 4, wherein the lower end cap (55), the connecting cylinder I (21), the connecting cylinder II (24), the outer casing (30), the upper end cap (58) and the upper joint casing (60) are connected by bolts (31).
6. The screw-driven downhole oil pumping device according to claim 5, wherein a seal ring (17) is arranged between the lower end cover (55), the connecting cylinder I (21), the connecting cylinder II (24), the outer shell (30), the upper end cover (58) and the upper joint sleeve (60).
7. The screw-driven downhole oil pumping device according to claim 1, wherein an O-shaped sealing ring I (2), an O-shaped sealing ring II (4) and an O-shaped sealing ring III (15) are respectively arranged between the lower end cover (55), the top tail (54), the top head (36) and the input shaft (1).
8. The screw-driven downhole oil pumping device according to claim 1, wherein the output shaft (8) is provided with a tightening ring I (34), a washer (18) and a tightening nut (33), and the tightening ring I tightens the tapered roller bearing (3) in the plug (36).
9. The screw-driven downhole oil pumping device according to claim 8, wherein a tightening ring II (35) for tightening the plug (36) is provided between the connecting cylinder I (21) and the plug (36).
Technical Field
The invention relates to an oil pumping unit for an oil field, in particular to a screw rod driven underground oil pumping device.
Background
Along with the development of oil reservoir, the high-quality oil reservoir of land has been developed almost totally, the well drilling degree of depth is constantly increaseed simultaneously, the bottom environment is complicated more originally, the requirement to drilling and production machinery is higher and higher, sucker rod oil recovery system in the past receives certain restriction when the application, and a lot of problems appear, along with the increase of oil recovery degree of depth, the efficiency of having pole oil recovery equipment is more and more low, equipment accident rate is higher and more, though there is certain alleviating measure, the eccentric wear problem of oil pole can not improve to the fundamental, just because the emergence of these new operating modes, the development of rodless oil pumping equipment has been promoted, and obtain the rapid development in recent years. Firstly, a series of oil extraction equipment products are researched from the improvement direction of reducing the accidents of the oil pumping rod and the reduction of the pump discharge capacity, the working mode of the oil extraction equipment is thoroughly changed, and a plurality of land application equipment are improved and applied to the underground. The underground oil pumping equipment is characterized in that: the oil extraction part is put underground from the land without the sucker rod, and some power equipment is put underground, so that the volume change of the power equipment is large, and the power equipment directly drives the oil pump to work underground and directly conveys oil to the ground. The rodless oil extraction method cancels the sucker rod, reduces additional load, greatly increases efficiency, and simultaneously, no matter the piston rod or the sucker rod can not generate eccentric wear. The oil extraction device directly solves two most important problems of the current development of the oil extraction technology on the oil pumping equipment, firstly, the efficiency of the oil extraction equipment is increased, the utilization rate of power is improved, and secondly, the adaptability of the pump under different oil reservoir conditions is enlarged. At present, the rodless oil pumping equipment which has mature technology and gradually widely applied comprises a hydraulic piston pump, a hydraulic jet pump, an electric submersible centrifugal pump, a screw pump and the like.
Wherein screw rod drive oil jack is a neotype oil recovery mode in the pit, adopt motor drive, drive screw rod rotary motion through transmission, thereby output straight reciprocating motion realizes oil recovery, screw rod drive oil recovery has the advantage of pumping in the pit, saved sucker rod and a lot of problems related to it, the advantage of hydraulic piston pump piston has been inherited in addition, electric drive is more convenient in the pit, also not have the loaded down with trivial details of the multistage pressure boost of centrifugal pump, insensitive to oil gas, the adaptation is strong, and screw drive is efficient moreover. But the screw-driven oil pumping unit has the characteristics of high energy consumption of a motor, low efficiency and the like.
Disclosure of Invention
Aiming at the problems, the invention mainly overcomes the defects in the prior art and provides a screw rod driving downhole oil pumping device.
The technical scheme provided by the invention for solving the technical problems is as follows: a screw rod driving underground oil pumping device comprises a lower end cover, a reversing assembly, a connecting cylinder I, a connecting cylinder II, a connecting sleeve, a rolling screw pair, an upper end cover, a reciprocating rod, an upper joint sleeve, a nut joint, a connecting rod and a pull rod;
the reversing assembly comprises a reversing shaft shell, a jacking tail, an upper limiting assembly, a stop block, a rotary steering assembly, a lower limiting assembly, a jacking head, an input shaft and an output shaft which are sequentially and axially arranged in the reversing shaft shell, wherein the jacking tail, the upper limiting assembly and the stop block are sequentially arranged on the input shaft, and the lower limiting assembly and the jacking head are sequentially arranged on the output shaft; tapered roller bearings are arranged in the jacking tail and the jacking head;
the lower limit component comprises a lower compression ring, a lower compression rod, a top cylinder, a lower cylindrical bolt spring, a lower fixed cylinder ring and a lower return ring, wherein the top cylinder is sleeved on the input shaft; the top cylinder, the lower cylindrical bolt spring and the lower return ring are all positioned in the lower fixed cylinder ring; one end of the lower cylindrical bolt spring is propped against the top cylinder, and the other end of the lower cylindrical bolt spring is pressed against the tail end face of the top cylinder; the lower return ring is positioned between the top cylinder and the stop block; a lower spring and a lower limiting clamp for pressing the lower spring are arranged in the radial groove; one end of the lower pressing rod props against the lower pressing ring, and the other end of the lower pressing rod presses the lower limiting clamp;
the rotary steering assembly comprises a sleeve, a transmission cylinder, a middle supporting shaft, a middle transmission cylinder, a radial sliding bearing, a lower bevel gear installed in the lower sliding bearing, a small bevel gear and an upper bevel gear installed in the upper sliding bearing; the transmission cylinder is sleeved at the end part of the input shaft and is positioned in the lower bevel gear; the end part of the output shaft is sequentially provided with a lower thrust bearing, a lower pressing block, a lower friction plate and a lower transmission plate which are positioned in the lower bevel gear; the middle transmission cylinder is sleeved on the output shaft, and an upper friction plate, an upper transmission plate, an upper pressing block and an upper thrust bearing are sequentially arranged at the position of the output shaft close to the middle transmission cylinder; the middle transmission cylinder, the upper friction plate, the upper transmission plate, the upper pressing block and the upper thrust bearing are all positioned in the upper bevel gear; the lower bevel gear, the small bevel gear and the upper bevel gear are sequentially in meshing transmission;
the upper limit position assembly comprises an upper return ring, an upper pressure rod, a pressure cylinder sleeved on the output shaft, an upper cylindrical bolt spring, an upper fixed cylinder ring with a radial groove and an upper return ring; the pressing cylinder, the upper cylindrical bolt spring and the upper return ring are all positioned in the upper fixed cylinder ring; one end of the pressing cylinder presses the upper push bearing; one end of the upper cylindrical bolt spring is pressed upwards, and the other end of the upper cylindrical bolt spring is propped against the bottom end face of the top head; the upper return ring is positioned between the pressing cylinder and the sleeve; an upper spring and an upper limit clamp for pressing the upper spring are arranged in the radial groove; one end of the upper pressure lever props against the upper return stroke ring, and the other end of the upper pressure lever compresses the upper limit clamp;
one end of the pull rod is connected with the upper part of the rolling screw pair, and the other end of the pull rod is respectively connected with the lower compression ring and the upper return ring; one end of the pressure lever is propped against the lower part of the rolling screw pair, and the other end of the pressure lever is pressed on the lower return ring; the upper compression ring is connected to the middle of the compression rod, the output shaft is connected with the rolling screw pair through a connecting sleeve, the reciprocating rod is positioned in the rolling screw pair, and the other end of the reciprocating rod is positioned in the upper joint sleeve and is connected with the connecting rod through a nut joint;
the lower end cover, the connecting cylinder I, the connecting cylinder II, the rolling spiral pair, the upper end cover and the upper joint sleeve are sequentially connected.
The further technical proposal is that a lower righting cylinder and a lower righting ring are arranged in the lower fixed cylinder ring.
The further technical proposal is that an upper righting cylinder and an upper righting ring are arranged in the upper fixed cylinder ring.
The rolling screw pair comprises a shell, a rolling screw pair screw rod, a rolling screw pair nut, a pressure ring and a pull ring; the pull ring is connected with the pull rod, and the compression bar props against the compression ring; a tapered roller bearing II is arranged in the connecting cylinder II, the rolling screw pair screw penetrates through the tapered roller bearing II and is connected with the output shaft through a connecting sleeve, the rolling screw pair nut is connected to the rolling screw pair screw, and a steel ball and a ball stopper are arranged on the rolling screw pair screw; the compression ring and the pull ring are respectively installed at two ends of the inner cavity of the shell, and the connecting cylinder II, the shell and the upper end cover are sequentially connected.
The further technical scheme is that the lower end cover, the connecting cylinder I, the connecting cylinder II, the shell, the upper end cover and the upper joint sleeve are connected through bolts.
The further technical scheme is that sealing rings are arranged among the lower end cover, the connecting cylinder I, the connecting cylinder II, the shell, the upper end cover and the upper joint sleeve.
The technical scheme is that an O-shaped sealing ring I, an O-shaped sealing ring II and an O-shaped sealing ring III are respectively arranged between the lower end cover, the top tail, the top head and the input shaft.
The technical scheme is that a jacking ring I, a washer and a jacking nut are arranged on the output shaft, and the jacking ring I jacks up the tapered roller bearing in the jacking head.
The further technical scheme is that a jacking ring II for jacking the jacking head is arranged between the connecting cylinder I and the jacking head.
The invention has the following beneficial effects: the invention inputs rotary power, the screw outputs reciprocating motion to drive the oil pump to extract oil; compared with oil extraction machines with other structural forms, the screw-driven oil extraction machine has the advantages that the occupied space for oil extraction is relatively small, and the transmission efficiency of the ball screw or the static pressure screw is relatively high.
Drawings
FIG. 1 is a schematic structural view of an upper portion of the present invention;
FIG. 2 is a schematic view of the structure of the interior of the present invention;
FIG. 3 is a schematic view of the structure of the lower part of the present invention;
FIG. 4 is a cross-sectional view of N-N in the drawing;
FIG. 5 is a cross-sectional view of J-J in the drawing;
FIG. 6 is a sectional view taken along line I-I;
FIG. 7 is a sectional view taken along line H-H in the drawing;
FIG. 8 is a sectional view taken along line G-G in the drawing;
FIG. 9 is a cross-sectional view F-F in the drawing;
FIG. 10 is a cross-sectional view of E-E in the drawing;
FIG. 11 is a cross-sectional view taken along line D-D in the drawing;
FIG. 12 is a cross-sectional view of C-D in the drawing.
Detailed Description
The present invention will be further described with reference to the following examples and the accompanying drawings.
As shown in fig. 1-12, the screw rod driven downhole oil pumping device of the present invention comprises a lower end cap 55, a reversing component, a connecting cylinder i 21, a connecting cylinder ii 24, a connecting sleeve 19, a rolling screw pair, an upper end cap 58, a reciprocating
the reversing assembly comprises a reversing shaft shell 16, a top tail 54, an upper limiting assembly, a stop block 6, a rotary steering assembly, a lower limiting assembly, a top head 36, an input shaft 1 and an output shaft 8 which are sequentially and axially arranged in the reversing shaft shell 16, wherein the top tail 54, the upper limiting assembly and the stop block 6 are sequentially arranged on the input shaft 1, and the lower limiting assembly and the top head 36 are sequentially arranged on the output shaft 8; the tapered roller bearings 3 are arranged in the jacking tail 54 and the jacking head 36;
the lower limit component comprises a lower pressure ring, a lower pressure rod 51, a top cylinder sleeved on the input shaft 1, a lower cylindrical bolt spring 52, a lower fixed cylinder ring with a radial groove and a lower return ring 50; the top cylinder, the lower cylindrical bolt spring 52 and the lower return ring 50 are all positioned in the lower fixed cylinder ring; one end of the lower cylindrical bolt spring 52 is pressed against the top cylinder, and the other end of the lower cylindrical bolt spring is pressed against the end surface of the top tail 54; the lower return ring 50 is positioned between the top cylinder and the stop block 6; a lower spring and a lower limiting clamp for pressing the lower spring are arranged in the radial groove; one end of the lower pressure rod 51 props against the lower pressure ring, and the other end of the lower pressure rod compresses the lower limit card;
the rotary steering component comprises a sleeve 44, a transmission cylinder 7, a middle supporting shaft 9, a middle transmission cylinder 10, a radial sliding bearing 47, a lower sliding bearing 49, a lower bevel gear arranged in the lower sliding bearing 49, a small bevel gear 46 and an upper bevel gear 45 arranged in the upper sliding bearing; the transmission cylinder 7 is sleeved at the end part of the input shaft 1 and is positioned in the lower bevel gear; the end part of the output shaft 8 is sequentially provided with a lower thrust bearing, a lower pressing block, a lower friction plate and a lower transmission plate which are positioned in the lower bevel gear; the middle transmission cylinder 10 is sleeved on the output shaft 8, and an upper friction plate 11, an upper transmission plate 12, an upper pressing block 13 and an upper thrust bearing 14 are sequentially arranged at the position, close to the middle transmission cylinder 10, of the output shaft 8; the middle transmission cylinder 10, the upper friction plate 11, the upper transmission plate 12, the upper pressing block 13 and the upper thrust bearing 14 are all positioned in the upper bevel gear 45; the lower bevel gear, the small bevel gear 46 and the upper bevel gear 45 are sequentially in meshing transmission;
the upper limit position assembly comprises an upper pressing ring 37, an upper pressing rod 39, a pressing cylinder 42, an upper cylindrical bolt spring, an upper fixing cylinder ring 38 and an upper return ring, wherein the pressing cylinder 42 is sleeved on the output shaft 8; the pressing cylinder 42, the upper cylindrical bolt spring and the upper return ring are all positioned in the upper fixed cylinder ring 38; one end of the pressing cylinder 42 presses the upper push bearing 14; one end of the upper cylindrical bolt spring is pressed on the pin 42, and the other end of the upper cylindrical bolt spring is propped against the bottom end face of the top head 36; the upper return ring is positioned between the pressing cylinder 42 and the sleeve 44; an upper spring and an upper limit clamp for pressing the upper spring are arranged in the radial groove; one end of the upper pressure rod 39 props against the upper pressure ring 37, and the other end of the upper pressure rod compresses the upper limit card;
in this embodiment, the rolling screw pair includes a housing 30, a rolling screw pair screw 27, a rolling screw pair nut 28, a press ring 29, and a
one end of the
The reversing working process of the invention is as follows: the motor drives the input shaft 1 to rotate, the input shaft 1 drives the transmission cylinder 7 to rotate, the transmission cylinder 7 drives the lower bevel gear to rotate, the lower bevel gear drives the small bevel gear 46 to rotate, the small bevel gear 46 drives the upper bevel gear 45, meanwhile, the gear is in external transmission, so that the rotating directions of the upper bevel gear and the lower bevel gear are opposite, and the coaxial rotation in two rotating directions is realized. The bevel gears drive the respective driven splines, which are constant motion. The transmission of the power of the input shaft 1 to the output shaft 8 requires the alternate cooperation of the top cylinder and the pressure cylinder 42, and the power of the spline is transmitted to the output shaft 8 through the action of the top cylinder and the pressure cylinder 42 on the friction plate. When the top cylinder props against the transmission cylinder 7, the transmission cylinder 7 compresses the lower friction plate and the lower transmission plate to drive the output shaft 8, at the moment, the pressing cylinder is in a separation state, when the pressing cylinder 42 presses the upper friction plate 11 and the upper transmission plate 12, the top cylinder is separated, and the power of the upper bevel gear is transmitted to the output shaft 8. This is two states of shaft power switching.
As shown in FIG. 1, the present invention is in a state where the pressure cylinder 42 acts on the clutch and the upper bevel gear cylinder outputs power. The
When the rolling screw pair nut 28 runs to the upper limit position, the
When the rolling screw pair nut 28 runs to the lower limit position, the pressing ring 29 presses the
The upward limit of the rolling screw pair nut 28 is provided with a
In this embodiment, in order to ensure the centering, it is preferable that a lower centering cylinder 53 and a lower centering ring 5 are provided in the lower fixed cylinder ring, and an upper centering cylinder and an upper centering ring 41 are provided in the upper fixed cylinder ring 38.
In this embodiment, for the convenience of disassembly, it is preferable that the lower end cover 55, the connecting cylinder i 21, the connecting cylinder ii 24, the outer shell 30, the upper end cover 58, and the upper
In order to improve the sealing effect, in a preferred embodiment, the sealing rings 17 are respectively arranged between the lower end cover 55, the connecting cylinder i 21, the connecting cylinder ii 24, the outer shell 30, the upper end cover 58 and the upper
In the preferred embodiment of the present invention, the output shaft 8 is provided with a tightening ring i 34, a washer 18, and a tightening nut 33, the tightening ring i tightens the tapered roller bearing 3 in the plug 36, and a tightening ring ii 35 for tightening the plug 36 is provided between the connecting cylinder i 21 and the plug 36.
Although the present invention has been described with reference to the above embodiments, it should be understood that the present invention is not limited to the above embodiments, and those skilled in the art can make various changes and modifications without departing from the scope of the present invention.