Universal shaft

Abstract

The invention relates to the technical field of well drilling, and provides a universal shaft which comprises a first buffer unit, a connecting unit and a second buffer unit which are sequentially connected, the first buffer unit comprises a first ball seat part and a first buffer part arranged in a first fixing cavity, one end of the first buffer part is connected with one end of the connecting unit, and the other end of the connecting unit is connected with the second buffer unit. The first buffering unit comprises a first ball seat part and a second buffering part arranged in a second fixing cavity, the first ball seat part makes contact with one end face of the connecting unit, the second buffering unit comprises a second ball seat part and a second buffering part arranged in the second fixing cavity, one end of the second buffering part is connected with the other end of the connecting unit, and the second ball seat part makes contact with the other end face of the connecting unit. The axial impact force among the first ball seat part, the second ball seat part and the connecting unit is reduced through the two buffering parts, namely, the impact force on the whole shaft is reduced, and the bearing capacity of the whole shaft is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of drilling, and in particular relates to a universal shaft. Background Art

[0002] Currently, commonly used universal joints are divided into ball-jointed universal joints, flexure-axis universal joints, and petal universal joints. Among them, flexure-axis universal joints have high material requirements and are relatively long. They have a short service life when subjected to alternating stress and large torque. The service life of ball-jointed universal joints is significantly improved in the above working conditions. However, as the current drilling temperature is getting higher and higher, the temperature resistance of ordinary ball-jointed universal joint rubber sleeves limits their scope of use. Petal-type universal joints have relatively low material costs and strong temperature resistance, but due to their petal torque transmission structure, they are mostly line contacts or point contacts when transmitting torque, which can easily cause the petal joints to break. In addition, since the universal shaft also bears radial force, it is easy to cause the ball seat to be shattered. Therefore, the temperature resistance and force-bearing capacity of the prior art universal shafts are relatively poor, especially the problem of the universal shaft bearing poor axial force needs to be solved urgently. Summary of the invention

[0003] In view of the above problems, the present invention proposes a universal joint, comprising: a first buffer unit, a connecting unit and a second buffer unit connected in sequence, the first buffer unit comprising a first ball seat portion and a first buffer portion arranged in a first fixed cavity, one end of the first buffer portion is connected to one end of the connecting unit, and the first ball seat portion is in contact with one end surface of the connecting unit, the second buffer unit comprises a second ball seat portion and a second buffer portion arranged in a second fixed cavity, one end of the second buffer portion is connected to the other end of the connecting unit, and the second ball seat portion is in contact with the other end surface of the connecting unit.

[0004] Optionally, the first buffer portion includes a first connecting head, a first elastic member, and a second connecting head which are connected in sequence, the second connecting head is connected to the connecting unit, and the first elastic member is wound around the first ball seat portion.

[0005] Optionally, the first ball seat portion includes a first outer ball seat and a first inner ball seat that are slidably connected, an end surface of the first inner ball seat is in contact with an end surface of the connecting unit, and the first elastic member is wound around the first inner ball seat.

[0006] Optionally, the first outer ball seat includes a first body and a contact surface connected to each other, and the contact surface is slidably connected to the first inner ball seat.

[0007] Optionally, the first inner ball seat includes an end head, a second body and a contact end face which are connected in sequence, the first outer ball seat is slidably connected to the end head, and the contact end face is in contact with an end face of the connecting unit.

[0008] Optionally, the first buffer portion and the second buffer portion have the same structure.

[0009] Optionally, the first ball seat portion and the second ball seat portion have the same structure.

[0010] Optionally, the connecting unit includes a first connecting end, a connecting shaft, and a second connecting end connected in sequence, the first buffer portion is connected to the first connecting end, the first ball seat portion is in cross-sectional contact with the first connecting end, the second connecting end is connected to the second buffer portion, and the second ball seat portion is in cross-sectional contact with the second connecting end.

[0011] Optionally, the first elastic member is a rectangular spring or a circular spring.

[0012] Optionally, the end head extends into a groove of the first outer ball seat and is able to slide in the groove.

[0013] The universal shaft of the present invention is connected to the first buffer part and the second buffer part respectively through the two ends of the connection unit, thereby reducing the torque and axial impact force on the entire shaft. The first ball seat part contacts with one end surface of the connection unit, which can alleviate the axial impact force on the connection unit through the first buffer part. The second ball seat part contacts with the other end surface of the connection unit, thereby reducing the axial impact force between the connection unit and the second ball seat part through the second buffer part, that is, reducing the impact force on the entire shaft and improving the bearing capacity of the entire shaft.

[0014] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 A schematic diagram of a universal joint shaft in an embodiment of the present invention is shown;

[0017] Figure 2 A schematic diagram of a first buffer portion of a universal joint shaft in an embodiment of the present invention is shown;

[0018] Figure 3 A schematic diagram of assembling the first buffer portion and the first ball seat portion of the universal joint shaft in an embodiment of the present invention is shown;

[0019] Figure 4 It shows another structural assembly schematic diagram of the first buffer portion and the first ball seat portion of the universal shaft in an embodiment of the present invention;

[0020] Figure 5 A schematic diagram of a second buffer portion of a universal joint shaft in an embodiment of the present invention is shown;

[0021] Figure 6 A schematic diagram of a first outer ball seat of a universal joint shaft in an embodiment of the present invention is shown;

[0022] Figure 7 A schematic diagram of a first inner ball seat of a universal joint shaft in an embodiment of the present invention is shown;

[0023] Figure 8 A schematic diagram of a connection unit of a universal joint shaft in an embodiment of the present invention is shown.

[0024] In the figure, 1, the first buffer unit; 2, the connecting unit; 3, the second buffer unit; 12, the first ball seat portion; 11, the first buffer portion; 32, the second ball seat portion; 31, the second buffer portion; 111, the first connecting head; 112, the first elastic member; 113, the second connecting head; 121, the first outer ball seat; 122, the first inner ball seat; 1211, the first body; 1212, the contact surface; 1221, the end head; 1222, the second body; 1223, the contact end surface; 21, the first connecting end; 22, the connecting shaft; 23, the second connecting end. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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 creative work are within the scope of protection of the present invention.

[0026] like Figure 1As shown, the present invention provides a universal shaft, comprising: a first buffer unit 1, a connection unit 2 and a second buffer unit 3 connected in sequence, the first buffer unit 1 comprising a first ball seat portion 12, and a first buffer portion 11 arranged in a first fixed cavity, one end of the first buffer portion 11 is connected to one end of the connection unit 2, and the first ball seat portion 12 is in contact with one end surface of the connection unit 2, the second buffer unit 3 comprises a second ball seat portion 32, and a second buffer portion 31 arranged in a second fixed cavity, one end of the second buffer portion 31 is connected to the other end of the connection unit 2, and the second ball seat portion 32 is in contact with the other end surface of the connection unit 2. It should be noted that the first buffer portion 11 and the second buffer portion 31 are elastic, and are connected to the first buffer portion 11 and the second buffer portion 31 respectively through the two ends of the connection unit 2. Since the first buffer portion 11 and the second buffer portion 31 can buffer the connection unit 2, the torque and axial impact force on the entire shaft are reduced. The contact between the first ball seat portion 12 and one end surface of the connecting unit 2 can alleviate the axial impact force between the connecting unit 2 and the first ball seat portion through the first buffer portion 11. The second ball seat portion 32 is in contact with the other end surface of the connecting unit 2, thereby reducing the axial impact force between the connecting unit 2 and the second ball seat portion 32 through the second buffer portion 31, that is, reducing the impact force on the entire shaft.

[0027] like Figure 2 As shown, in one embodiment, the first buffer portion 11 includes a first connector 111, a first elastic member 112, and a second connector 113 connected in sequence, the second connector 113 is connected to the connection unit 2, and the first elastic member 112 is wound around the first ball seat portion 12. It should be noted that the first connector 111 can be connected to a drive or power system to drive the entire structure to move. The first elastic member 112 is located in the middle of the first buffer portion 11. During operation, when the first elastic member 112 is compressed, the first elastic member 112 can withstand part of the torque and axial impact force transmitted, so that the torque and axial impact force transmitted to the connection unit 2 are reduced.

[0028] like Figure 3 As shown, in one embodiment, the first ball seat portion 12 includes a first outer ball seat 121 and a first inner ball seat 122 that are slidably connected, the end face of the first inner ball seat 122 is in contact with an end face of the connecting unit 2, and the first elastic member 112 is wound around the first inner ball seat 122. It should be noted that when the first elastic member 112 is compressed, the axial impact force of the first inner ball seat 122 is fully buffered due to the sliding connection between the first outer ball seat 121 and the first inner ball seat 122, and the axial impact force borne by the first inner ball seat 122 when it contacts the connecting unit 2 again is also reduced, that is, the axial impact force acting on the connecting unit 2 is reduced.

[0029] like Figure 6As shown, in one embodiment, the first outer ball seat 121 includes a first body 1211 and a contact surface 1212 connected to each other, and the contact surface 1212 is slidably connected to the first inner ball seat 122. Optionally, the contact surface 1212 is polished into a smooth arc, and the arc surface is sprayed with a diamond-like coating (DLC coating for short) by a plasma-assisted chemical vapor deposition process or treated by a salt bath nitriding and salt bath oxidation process, and a self-lubricating coating is sprayed on the surface after the surface treatment, and the material of the first body 1211 and the contact surface 1212 can be selected from alloy steel such as 4330V, 40Cr, 40CrNi, 40CrNiMo, 35CrMo, 42CrMo, 42CrMoS, 12CrNi3, 20CrMnTi, and the material hardness is adjusted by heat treatment of the material. It should be noted that when the first elastic member 112 is compressed, the first inner ball seat 122 can move with it and slide on the contact surface 1212, thereby achieving axial buffering of the first inner ball seat 122.

[0030] like Figure 7 As shown, in one embodiment, the first inner ball seat 122 includes a terminal 1221, a second body 1222 and a contact end face 1223 connected in sequence, the first outer ball seat 121 and the terminal 1221 are slidably connected, and the contact end face 1223 contacts the end face of the connection unit 2. It should be noted that the terminal 1221, the second body 1222 and the contact end face 1223 are all required to be processed by quenching + tempering process, the terminal 1221 needs to be polished into a smooth arc, and the surface of the terminal 1221 is sprayed with DLC coating by plasma-assisted chemical vapor deposition process or salt bath nitriding and salt bath oxidation process to improve wear resistance, and then sprayed with self-lubricating coating to improve lubrication performance. The end face is a flat end face, which is in close contact or fit with the connection unit 2 during assembly. The material of the first inner ball seat 122 can be selected from alloy steel such as 4330V, 40Cr, 40CrNi, 40CrNiMo, 35CrMo, 42CrMo, 42CrMoS, 12CrNi3, 20CrMnTi. During operation, the inner ball seat mainly connects the connection unit 2 and the outer ball seat 300, and plays a role in transmitting the axial force generated during the movement. Since the inner ball seat is in contact or close to the connection unit 2, the axial force can be transmitted in time, which has a protective effect on the connection unit 2. Moreover, the first outer ball seat 121 and the end 1221 are slidably connected, and the compression of the first elastic member 112 can further buffer the axial force of the first inner ball seat 122.

[0031] like Figure 3 and Figure 5As shown, in one embodiment, the first buffer portion 11 and the second buffer portion 31 have the same structure. Optionally, the second buffer portion 31 structure includes a third connector, a second elastic member and a fourth connector connected in sequence, the third connector is connected to the connection unit 2, and the second elastic member is wound around the second ball seat portion 32. Since the first buffer portion 11 and the second buffer portion 31 have the same structure, the two are the same in function and effect, and the function and effect of the second buffer portion 31 are not described here.

[0032] In one embodiment, the first ball seat portion 12 and the second ball seat portion 32 have the same structure. Optionally, the second ball seat portion 32 includes a second outer ball seat and a second inner ball seat that are slidably connected, the end face of the second inner ball seat is in contact with the other end face of the connecting unit 2, and the second elastic member is wound around the second inner ball seat. It should be noted that when the second elastic member is compressed, the axial impact force of the second inner ball seat is fully buffered due to the sliding connection between the second outer ball seat and the second inner ball seat, and the axial impact force that the second inner ball seat bears when it contacts the connecting unit 2 again is also reduced, that is, the axial impact force acting on the connecting unit 2 is reduced.

[0033] like Figure 8 As shown, in one embodiment, the connection unit 2 includes a first connection end 21, a connection shaft 22, and a second connection end 23 which are connected in sequence, the first buffer portion 11 is connected to the first connection end 21, the first ball seat portion 12 is in cross-section contact with the first connection end 21, the second connection end 23 is connected to the second buffer portion 31, and the second ball seat portion 32 is in cross-section contact with the second connection end 23. Optionally, the material of the first connection end 21, the connection shaft 22, and the second connection end 23 can be made of alloy steel such as 4330V, 40Cr, 40CrNi, 40CrNiMo, 35CrMo, 42CrMo, 42CrMoS, 12CrNi3, 20CrMnTi, and the material is tempered as a whole. During the operation of the entire shaft, the connection unit 2 needs to transmit the axial force generated during the drilling process to the second buffer portion 31, and the axial force is further buffered on the second buffer portion 31.

[0034] like Figure 3 and Figure 4 As shown, in one embodiment, the first elastic member 112 is a rectangular spring or a circular spring. Optionally, the material of the first elastic member 112 can be selected from alloy steel such as 4330V, 40Cr, 40CrNi, 40CrNiMo, 35CrMo, 42CrMo, 42CrMoS, 12CrNi3, 20CrMnTi, and the matrix can be carburized and quenched to adjust the material hardness as needed. By selecting a rectangular spring or a circular spring, different axial impact forces can be adapted.

[0035] In one embodiment, the end head 1221 extends into the groove of the first outer ball seat 121 and can slide in the groove. When subjected to axial impact force, the end head 1221 can slide in the groove and under the action of the first elastic member 112, axial buffering is achieved.

[0036] In actual work, the first connector 111 connects to the screw motor rotor, receives and transmits the screw motor rotation torque, transmits it to the first elastic member 112 and the second connector 113, and transmits the rotation torque to the connection unit 2, transmits the torque to the second buffer unit 3 through the connection unit 2, and the second elastic member and the fourth connector on the second buffer unit 3 transmit the torque to the lower transmission system connected to the fourth connector. During the torque transmission process, the first elastic member 112 and the second elastic member are compressed to achieve torque buffering. At the same time, the entire shaft also bears axial force. The first connector 111 transmits the axial force it bears to the first outer ball seat 121, which is then transmitted to the first inner ball seat 122 through the first outer ball seat 121, and then transmitted to the connection unit 2 through the first inner ball seat 122. Then, the second inner ball seat promptly transmits the axial force on the connection unit 2 to the second outer ball seat. During the axial force transmission process, the compression of the first elastic member 112 and the second elastic member reduces the axial impact on each outer ball seat, thereby completing the smooth transmission of power. Thereby improving the axial bearing capacity of the entire shaft, it is less likely to cause damage or even breakage of components due to poor bearing capacity.

[0037] Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent substitutions for some of the technical features therein; and these modifications or substitutions do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A universal shaft, characterized in that: include: A first buffer unit (1), a connecting unit (2) and a second buffer unit (3) are connected in sequence, wherein the first buffer unit (1) comprises a first ball seat portion (12) and a first buffer portion (11) arranged in a first fixed cavity, one end of the first buffer portion (11) is connected to one end of the connecting unit (2), and the first ball seat portion (12) contacts one end surface of the connecting unit (2); the second buffer unit (3) comprises a second ball seat portion (32) and a second buffer portion (31) arranged in a second fixed cavity, one end of the second buffer portion (31) is connected to the other end of the connecting unit (2), and the second ball seat portion (32) contacts the other end surface of the connecting unit (2).

2. The universal joint shaft according to claim 1, characterized in that: The first buffer portion (11) comprises a first connecting head (111), a first elastic member (112) and a second connecting head (113) which are connected in sequence, the second connecting head (113) is connected to the connecting unit (2), and the first elastic member (112) is wound around the first ball seat portion (12).

3. The universal joint shaft according to claim 2, characterized in that: The first ball seat portion (12) comprises a first outer ball seat (121) and a first inner ball seat (122) which are slidably connected, the end face of the first inner ball seat (122) contacts an end face of the connecting unit (2), and the first elastic member (112) is wound around the first inner ball seat (122).

4. The universal joint shaft according to claim 3, characterized in that: The first outer ball seat (121) comprises a first body (1211) and a contact surface (1212) which are connected to each other, and the contact surface (1212) is slidably connected to the first inner ball seat (122).

5. The universal joint shaft according to claim 3, characterized in that: The first inner ball seat (122) comprises an end head (1221), a second body (1222) and a contact end face (1223) which are connected in sequence; the first outer ball seat (121) and the end head (1221) are slidably connected; and the contact end face (1223) contacts the end face of the connection unit (2).

6. The universal joint shaft according to claim 1, characterized in that: The first buffer portion (11) and the second buffer portion (31) have the same structure.

7. The universal joint shaft according to claim 1, characterized in that: The first ball seat portion (12) and the second ball seat portion (32) have the same structure.

8. The universal joint shaft according to claim 1, characterized in that: The connection unit (2) comprises a first connection end (21), a connection shaft (22) and a second connection end (23) which are connected in sequence; the first buffer portion (11) is connected to the first connection end (21); the first ball seat portion (12) is in cross-sectional contact with the first connection end (21); the second connection end (23) is connected to the second buffer portion (31); and the second ball seat portion (32) is in cross-sectional contact with the second connection end (23).

9. The universal joint shaft according to claim 2, characterized in that: The first elastic member (112) is a rectangular spring or a circular spring.

10. The universal joint shaft according to claim 5, characterized in that: The end head (1221) extends into a groove provided in the first outer ball seat (121) and is able to slide in the groove.

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