Locking device and corresponding method

Abstract

The present invention relates to a locking device, comprising: - a first connecting member having a threaded section and a first set of n1 teeth; and - a second connecting member having a threaded section and a second set of n2 teeth, wherein, after factorization of n1 and n2, n1 and n2 have a non-common factor greater than 1, wherein the locking device further comprises a single locking ring of fixed diameter, wherein the locking ring comprises a third set of teeth and a fourth set of teeth, the third set of teeth and the fourth set of teeth being configured to engage with the first set of teeth and the second set of teeth, respectively, and wherein the locking ring is movable along the axial direction of the connecting member between a release position and a locking position, wherein in the release position the second set of teeth disengages from the fourth set of teeth, and in the locking position the first set of teeth and the second set of teeth engage with the third set of teeth and the fourth set of teeth, respectively.

Description

Technical Field

[0001] The present invention relates to a locking device for locking the rotational position of a first connecting member relative to a second connecting member, for example, such a locking device is typically required during drilling operations as part of onshore or offshore wellbore-related activities. Background Technology

[0002] Drilling equipment typically includes a top drive unit and a rotating rod. The top drive unit includes one or more top drive motors, such as electric top drive motors, and the rotating rod extends along the workline and is driven by the one or more motors to transmit rotational motion to the drill string when connected to the top drive. The connection between the top drive motor and the rotating rod and / or between the rotating rod and the drill string can benefit from locking devices, particularly when using a first connecting member and a second connecting member, wherein the first connecting member has one of an internal thread segment and an external thread segment, and the second connecting member has the other of an internal thread segment and an external thread segment to mate with the thread segment of the first connecting member.

[0003] In particular, when the applied torque is in the loosening direction of the threaded section used to connect the first and second connecting members, the locking device prevents the connection from loosening accidentally.

[0004] EP1664477A1 discloses a prior art locking device comprising two separate locking rings that engage with each other by corresponding teeth and grooves on their first sides. Each of the two locking rings has a different number of teeth and grooves on its second side. The two second sides facing the connecting member are formed to engage with corresponding numbers of grooves and teeth formed on the shoulders of opposite sides of the connecting member after the locking rings are separated in the axial direction, while maintaining the engagement between the first and second locking rings.

[0005] While the locking device of EP1664477A1 has the advantage that the locking rings do not need to extend radially relative to the connecting member, its disadvantage is the use of two locking rings and the resulting three connections: the connection between each locking ring and its corresponding connecting member, and the connection between the two locking rings. This not only presents a design challenge in providing sufficiently strong connections between all components, but also in keeping the two locking rings separate to maintain locking engagement. Summary of the Invention

[0006] Therefore, the object of the present invention is to provide a locking device that is easy to design and use.

[0007] According to the present invention, a locking device is provided, comprising:

[0008] - A first connecting member having one of an internal thread segment and an external thread segment, and including a first set of teeth having a complete gear tooth number n1; and

[0009] - A second connecting member having either an internal thread segment or an external thread segment to mate with the thread segment of the first connecting member for connecting the first connecting member to the second connecting member, and the second connecting member including a second set of teeth having a full gear tooth number n2.

[0010] After factorization of n1 and n2, n1 and n2 have non-common factors greater than 1.

[0011] The locking device further includes a single locking ring of fixed diameter.

[0012] The locking ring includes a third set of teeth and a fourth set of teeth. The third set of teeth is configured to engage with the first set of teeth, and the fourth set of teeth is configured to engage with the second set of teeth.

[0013] Furthermore, at least when the first connecting member is connected to the second connecting member, the locking ring is movable in the axial direction of the first and second connecting members between a release position and a locking position. In the release position, the second set of teeth disengages from the fourth set of teeth to allow the first connecting member to rotate relative to the second connecting member. In the locking position, the first set of teeth engages with the third set of teeth, and the second set of teeth engages with the fourth set of teeth to lock the rotational position of the first connecting member relative to the second connecting member.

[0014] It's important to note that any one of the first to fourth groups of teeth can be formed from one or more gear segments, thus not forming a complete gear. To avoid distinguishing between a group of teeth forming a complete gear and a group of teeth formed from one or more gear segments, the concept of the complete gear teeth number is introduced. This refers to the number of teeth in a complete gear defined by a group of teeth. When a group of teeth has formed a complete gear, the complete gear teeth number is equal to the actual number of teeth in that group. When a group of teeth forms part of a complete gear, the complete gear teeth number will be higher than the actual number of teeth in that group.

[0015] Preferably, the first and second sets of teeth form a complete gear. This can be advantageous because it makes it easier to determine which tooth in the first set is substantially aligned with another tooth in the second set, which can be useful for correctly orienting the locking ring to move it toward the locking position, as will be explained in more detail below.

[0016] The advantage of the locking device according to the invention is that it uses only a single locking ring of a fixed diameter, resulting in only two connections: the connection between the locking ring and the first and second connecting members, and locking only requires movement of the locking ring relative to the connecting members. This leads to fewer design challenges and makes the locking device easier to use.

[0017] The advantage of using the full gear tooth counts n1 and n2 is that the number of lockable orientations of the first connecting member relative to the second connecting member increases and exceeds the maximum value of n1 and n2, where n1 and n2 have non-common factors greater than 1 after factorization. Table 1 below provides some examples of suitable combinations of n1 and n2.

[0018] Table 1: Examples of suitable combinations of complete gear tooth count n1 and complete gear tooth count n2

[0019]

[0020] In the example above, n1 is always greater than n2, but this is not always the case. For example, when n1 and n2 are swapped, the same applies to n2 being greater than n1. It is explicitly stated here that the fact that the quantities n1 and n2 are different is insufficient to result in a larger number of lockable orientations. For instance, when one quantity is a multiple of the other, such as n1 being 6 and n2 being 3 (i.e., n1 = 2 * n2), the resulting number of lockable orientations is equal to the maximum of n1 and n2, which is 6 (n1) in this example.

[0021] As can be seen from the examples in Table 1, after factoring n1 and n2, it is preferable to choose complete gear tooth numbers n1 and n2 that have no common factors other than 1. This is correct, for example, when one of n1 and n2 is a prime number and the other is not a multiple of that prime number. Thus, the number of lockable orientations is n1*n2. The more lockable orientations there are, the fewer adjustments are needed to the mutual rotational orientation between the first and second connecting members, thereby allowing the locking ring to lock the rotational position of the first connecting member relative to the second connecting member, i.e., to lock the mutual rotational orientation.

[0022] In one implementation, one of the complete gear teeth numbers n1 and n2 is 56, and the other of the complete gear teeth numbers n1 and n2 is 55.

[0023] In one embodiment, the first set of teeth disengages from the third set of teeth in the release position. The advantage is that the locking ring can rotate relative to the first and second connecting members, thereby allowing the orientation of the locking ring to be adjusted to the mutual orientation between the first and second connecting members, and thus allowing the locking ring to lock in the rotational position, preferably without needing to adjust the mutual orientation between the first and second connecting members.

[0024] In one implementation, the third set of teeth has the full number of gear teeth n3, which is equal to the full number of gear teeth n1.

[0025] In one implementation, the fourth set of teeth has the full number of gear teeth n4, which is equal to the full number of gear teeth n2.

[0026] In one embodiment, the tooth extends axially parallel to the longitudinal axis on the outside of the corresponding connecting member and extends radially outward from the tooth root to the tooth tip from the corresponding connecting member.

[0027] In one embodiment, the locking device includes a retaining member to hold the locking ring in a released or locked position. Preferably, the retaining member engages with a first set of teeth and / or a second set of teeth to hold the locking ring in position.

[0028] In one embodiment, the locking ring includes, for example, a first seat and a second seat in the form of a hole, the first seat and the second seat being configured to receive a retaining member, wherein the locking ring is held in a released position when the retaining member is received in the first seat, and wherein the locking ring is held in a locked position when the retaining member is received in the second seat.

[0029] In one implementation, the third set of teeth cannot pass through the second set of teeth, such that the engagement of the third set of teeth with the second set of teeth can additionally or alternatively retain the locking ring in the locked position.

[0030] In one embodiment, the first seat is arranged between the third and fourth sets of teeth, and the second seat is arranged on the opposite side of the fourth set of teeth.

[0031] In one embodiment, the locking ring is provided with a visual indication of the relative rotational orientation of the third and fourth sets of teeth, for example, a line indicating the alignment position of the third set of teeth with the fourth set of teeth.

[0032] As an illustration, the engagement of one set of teeth with another set of teeth and the locking of the rotational positions of the first and second connecting members can allow some movement between the corresponding components due to tooth backlash, which is common for tooth engagement. Alternatively, the tooth backlash can be limited to a maximum of 0.1 times the circumferential tooth pitch of the corresponding set of teeth, preferably a maximum of 0.05 times the circumferential tooth pitch, more preferably a maximum of 0.02 times the circumferential tooth pitch, and most preferably a maximum of 0.01 times the circumferential tooth pitch.

[0033] The present invention also relates to a method for connecting and locking a first connecting member and a second connecting member of a locking device according to the present invention, wherein the method comprises the following steps:

[0034] a) Connecting the first connecting member to the second connecting member by engaging the corresponding threaded segments; and

[0035] b) Move the locking ring from the released position to the locked position.

[0036] In one embodiment, the locking ring is rotated to a lockable orientation before the lock is moved to the locking position. Preferably, the locking ring is provided with visual indications of the relative rotational orientation of the third and fourth sets of teeth, for example, lines indicating the alignment of the third and fourth sets of teeth, wherein the method includes, for example, aligning the visual indications on the locking ring with the first and second sets of teeth by aligning the lines on the locking ring with the teeth of the first set of teeth that are aligned with the teeth of the second set of teeth.

[0037] In one embodiment, a retaining member is provided to hold the locking ring in the released position, wherein the method includes the step of removing the retaining member before moving the locking ring to the locked position. Preferably, the retaining member is removed from the first seat.

[0038] In one embodiment, the method includes the step of setting a retaining member to maintain the locked state in the locked position after the locking ring has been moved to the locked position. Preferably, the retaining member is disposed in the second seat. Attached Figure Description

[0039] The invention will now be described in a non-limiting manner with reference to the accompanying drawings, wherein like parts are designated by like reference numerals, wherein:

[0040] Figure 1 A locking device according to an embodiment of the present invention is schematically depicted, wherein the first and second connecting members are in an open state and are spaced apart from each other;

[0041] Figure 2 schematically depicted Figure 1 A locking device in which a first connecting member is inserted into a second connecting member;

[0042] Figure 3 schematically depicted Figure 2 The locking device, wherein the threaded section of the first connecting member engages with the threaded section of the second connecting member;

[0043] Figure 4 schematically depicted Figure 3 A locking device wherein the first and second connecting members are fastened together;

[0044] Figure 5 The diagram schematically depicts the alignment of the locking ring with the teeth on the first and second connecting members. Figure 4 Locking device;

[0045] Figure 6The illustration schematically depicts the scene after the locking ring retaining bolt has been removed. Figure 5 Locking device;

[0046] Figure 7 The diagram schematically depicts the process after the locking ring has been moved from the released position to the locked position. Figure 6 Locking device;

[0047] Figure 8 The schematic depiction shows the situation before the locking ring retains the bolt. Figure 7 Locking device;

[0048] Figure 9 The diagram schematically depicts the situation after the locking ring retains the bolt in place. Figure 8 The locking device; and

[0049] Figure 10 A cross-sectional view of the locking device is schematically depicted, where the right side of the figure corresponds to... Figures 7 to 9 The locking position of the locking ring is shown, and the left side of the figure corresponds to the position shown. Figure 5 and Figure 6 The lock ring is shown in its release position. Detailed Implementation

[0050] Figures 1 to 10 A locking device LA according to an embodiment of the invention is schematically depicted, wherein the various figures indicate different steps for connecting and locking the first connecting member CM1 and the second connecting member CM2 to each other, or, if viewed in reverse order, different steps for releasing and disconnecting the first and second connecting members CM1, CM2.

[0051] The first connecting member CM1 includes an external thread section MTS, and the second connecting member CM2 includes an internal thread section FTS to mate with the external thread section MTS, as will be referred to below. Figures 1 to 4 Explanation. For example... Figure 1 As shown, the external thread segment MTS and / or the internal thread segment FTS are preferably tapered. This has the advantage of making it easier to align the first and second connecting members CM1 and CM2.

[0052] exist Figure 1 In this configuration, the first connecting member CM1 and the second connecting member CM2 are arranged at a certain distance from each other. The longitudinal axis LA1 of the first connecting member CM1 is substantially aligned with the longitudinal axis LA2 of the second connecting member CM2. This allows the external thread segment MTS to be inserted into the internal thread segment FTS when the first and second connecting members CM1 and CM2 move relative to each other in directions parallel to their longitudinal axes LA1 and LA2. Preferably, the longitudinal axes LA1 and LA2 coincide.

[0053] exist Figure 2 In the above-mentioned relative movement of inserting the external thread segment MTS into the internal thread segment FTS, the external thread segment MTS and the internal thread segment FTS are in contact with each other or almost in contact but not mating with each other. This means that in this position, the external thread segment MTS can still retract from the internal thread segment. If in Figure 1 If there is an initial misalignment, then contact (not mating) can align the first and second connecting members CM1 and CM2 with each other.

[0054] exist Figure 3 In the middle, the first connecting member CM1 has rotated relative to the second connecting member CM2 around the longitudinal axis LA1 as shown by arrow A1, so that the external thread segment MST and the internal thread segment FST are engaged. This means that without first rotating in the opposite direction to arrow A1, the external thread segment MST will no longer be able to retract. Figure 2 and Figure 3 The rotation that causes the threaded segments to engage can be alternatively described as screwing the external threaded segment into the internal threaded segment or screwing the internal threaded segment into the external threaded segment. It is explicitly stated here that, due to the threaded connection of the threaded segments, they also approach each other in the axial direction.

[0055] Figure 3 The first connecting member CM1 is depicted as being able to rotate further in direction A1 or in the opposite direction. Figure 4 It depicts the situation where the first connecting member CM1 has been rotated further along direction A1 until it can no longer be rotated. Figure 3 This situation can be considered as the connection state of the first and second connecting members, while Figure 4 The situation can be considered as the connection and fastening of the first and second connecting members.

[0056] The connection between the first and second connecting members can be used in many different applications, such as transmitting rotary motion from the rotating rod of a top drive motor of a drilling rig to the drill pipe. When the transmitted rotary motion is in the direction of arrow A1, the tightness of the threaded connection ensures that the rotary motion is easily transmitted. However, when the transmitted rotary motion is in the opposite direction to arrow A1, the threaded connection between the first and second connecting members may unexpectedly loosen and become as follows: Figure 3 even Figure 2 The state is shown. To prevent this situation, the locking device LA includes measures to lock the rotational position of the first and second connecting members independently of the connection provided by the external threaded section and the internal threaded section, as will be explained in more detail below.

[0057] The first connecting member CM1 includes a first set of S1 teeth T1 having the full number of gear teeth n1. The reference numeral T1 is used to indicate only a few teeth T1 to keep the drawing clear. The second connecting member CM2 includes a second set of S2 teeth T2 having the full number of gear teeth n2. Similarly, the reference numeral T2 is used to indicate only a few teeth T2 to keep the drawing clear.

[0058] Tooth T1 and tooth T2 each extend axially parallel to the longitudinal axes LA1 and LA2 on the outside of the corresponding connecting members CM1 and CM2. Tooth T1 and tooth T2 extend radially outward from the tooth root to the tooth tip from the corresponding connecting members CM1 and CM2.

[0059] The first group S1 and the second group S2 teeth T1 and T2 are positioned as follows: [The first and second connecting members CM1 and CM2 are in a position such that...] Figure 4 When connected and fastened as shown, complete gears are formed by arranging them adjacent to each other. Providing complete gears means that no teeth are omitted, and therefore the actual number of teeth T1 and T2 is equal to the number of teeth n1 and n2 of the complete gear, respectively. However, the first group S1 and the second group S2 can also be formed by one or more gear segments, not forming complete gears, but arranged in a manner similar to complete gears, and therefore the number of teeth of the complete gear refers to the number of teeth that would appear if the missing teeth between one or more gear segments were filled to complete the gear.

[0060] The locking device LA further includes a single locking ring LR of fixed diameter. For example... Figure 10 As shown, the locking ring LR is provided with a third group of S3 teeth T3 and a fourth group of S4 teeth T4. The third group of S3 teeth T3 is configured to cooperate with the first group of S1 teeth T1, and the fourth group of S4 teeth T4 is configured to cooperate with the second group of S2 teeth T2.

[0061] In this embodiment, the third group S3 and the fourth group S4 teeth T3 and T4 form complete gears arranged adjacent to each other, having complete gear teeth n3 and n4 respectively, wherein preferably n1 = n3 and n2 = n4. Similarly, as described above with respect to the first group S1 and the second group S2, it is envisioned that the third group S3 and the fourth group S4 are formed by one or more gear segments.

[0062] When the third set of S3 teeth T3 engages with the first set of S1 teeth T1, and simultaneously the fourth set of S4 teeth T4 engages with the second set of S2 teeth T2, the rotational position of the first connecting member CM1 relative to the second connecting member CM2 is locked. This rotational position can be alternatively referred to as lockable orientation.

[0063] After factorization of n1 and n2, the complete gear teeth n1 and n2 have non-common factors greater than 1, which increases the number of lockable orientations of the first connecting member CM1 relative to the second connecting member and is higher than the maximum value of n1 and n2.

[0064] The locking ring LR is further movable axially (i.e., parallel to the longitudinal axes LA1, LA2 of the first and second connecting members CM1, CM2) along the first and second connecting members CM1, CM2 between a release position and a locking position. In the release position, the teeth T3, T4 of the locking ring LR are disengaged from the teeth T1, T2 on the first and second connecting members CM1, CM2. In the locking position, the teeth T3, T4 are respectively engaged with the teeth T1, T2. Although only the tooth T4 needs to be disengaged from the tooth T2 from the locked state to the released state, the advantage of disengaging the tooth T3 from the tooth T1 is that the locking ring LR can rotate freely relative to the first and second connecting members CM1, CM2.

[0065] The locking ring LR is further provided with an upper hole UH and a lower hole LH extending perpendicular to the longitudinal axis LA1 of the first connecting member CM1. The upper hole UH extends between the third set S3 of teeth T3 and the fourth set S4 of teeth T4, and the lower hole LH extends on the opposite side of the fourth set S4 of teeth T4. The upper hole UH and the lower hole LH are configured to accommodate a retaining member RM, in this case in the form of a bolt.

[0066] When the retaining member RM is accommodated in the upper hole UH, the locking ring LR cannot pass through the first set S1 of teeth T1 on the first connecting member CM1 and thus remains in the release position. This is shown in Figures 1 to 5 and Figure 10 the left side as shown.

[0067] When the retaining member RM is accommodated in the lower hole LH, the locking ring LR cannot pass through the second set S2 of teeth T2 on the second connecting member CM2 and thus remains in the locking position. This is shown in Figure 9 and Figure 10 the right side as shown.

[0068] It can be clearly seen from Figure 10 that different sets of teeth are arranged at different distances from the longitudinal axes LA1, LA2. The first set S1 is arranged at a distance D1, the second set S2 is arranged at a distance D2, the third set S3 is arranged at a distance D3, and the fourth set S4 is arranged at a distance D4. In order for the third set S3 to cooperate with the first set S1, D1 needs to be greater than D3. In order for the fourth set S4 to cooperate with the second set S2, D2 needs to be greater than D4. In order for the fourth set S4 to disengage from the second set S2 without engaging with the first set S1, D4 needs to be greater than D1. Therefore, the following can apply: D3 < D1 < D4 < D2. As a result, the third set S3 cannot pass through the second set S2 on the second connecting member CM2, which will also cause the locking ring LR to remain in the locking position.

[0069] The third group S3 and the fourth group S4 have a fixed mutual rotational orientation. This fixed mutual rotational orientation can be indicated on the outside of the locking ring LR, in this example as line LI, which can, for example, indicate the alignment position of tooth T3 and tooth T4. (As used in the illustrated embodiment) Figure 5 As shown, this allows the locking ring LR to rotate relative to the first and second connecting members CM1, CM2 to match the mutual rotational orientation of the first and second sets of S1, S2, for example, by finding a tooth T1 aligned with tooth T2 and positioning line L1 at these teeth. Due to the matched rotational orientation, the third set of S3 can engage with the first set of S1, while the fourth set of S4 can engage with the second set of S2.

[0070] However, before engagement, such as Figure 6 As shown, the retaining member RM needs to be removed from the upper hole UH. This allows the locking ring LR to be removed from... Figure 6 The release position in the middle is moved to, for example Figure 7 The locking position is shown in the diagram. Then, as... Figure 8 As shown, the retaining member RM moves toward and is received in the lower hole LH, thereby holding the locking ring LR in place as shown. Figure 9 The locking position is shown in the figure.

Claims

1. A locking device, comprising: • A first connecting member having one of an internal thread segment and an external thread segment, and including a first set of teeth having a complete gear tooth number n1; as well as A second connecting member, having either an internal thread segment or an external thread segment, mates with the thread segment of the first connecting member for connecting the first connecting member to the second connecting member, and the second connecting member includes a second set of teeth having a full gear tooth count n2. After factorization of n1 and n2, n1 and n2 have non-common factors greater than 1. The locking device further includes a single locking ring of fixed diameter. The locking ring includes a third set of teeth and a fourth set of teeth. The third set of teeth is configured to engage with the first set of teeth, and the fourth set of teeth is configured to engage with the second set of teeth. Furthermore, at least when the first connecting member is connected to the second connecting member via the engagement of an external thread segment and an internal thread segment, the locking ring moves axially between a released position and a locked position. In the released position, the first set of teeth disengages from the third set of teeth, and the second set of teeth disengages from the fourth set of teeth, allowing the locking ring to rotate freely relative to the connected first and second connecting members. This allows the locking ring to be rotated to a lockable orientation before axially moving it to the locked position. In the locked position, the first set of teeth engages with the third set of teeth, and the second set of teeth engages with the fourth set of teeth to lock the rotational position of the first connecting member relative to the second connecting member.

2. The locking device according to claim 1, further comprising a retaining member to hold the locking ring in a released position or a locked position.

3. The locking device according to claim 2, wherein, The retaining member engages with the first set of teeth and / or the second set of teeth to maintain the position of the locking ring.

4. The locking device according to claim 2 or 3, wherein, The locking ring includes a first seat and a second seat, which are configured to accommodate the retaining member. When the retaining member is accommodated in the first seat, the locking ring is held in a released position, and when the retaining member is accommodated in the second seat, the locking ring is held in a locked position.

5. The locking device according to claim 4, wherein, The first seat is disposed between the third set of teeth and the fourth set of teeth, and the second seat is disposed on the opposite side of the fourth set of teeth.

6. The locking device according to claim 5, wherein, The locking ring is provided with an upper hole and a lower hole extending perpendicular to the longitudinal axis of the first connecting member, wherein the upper hole extends between the third set of teeth and the fourth set of teeth, and the lower hole extends on the opposite side of the fourth set of teeth, and the upper hole and the lower hole are configured to accommodate a retaining member in the form of a bolt.

7. The locking device according to claim 1, wherein, After factorization of n1 and n2, the complete gear teeth number n1 and n2 have no common factors other than 1.

8. The locking device according to claim 7, wherein, n1 or n2 is a prime number, while the other is not a multiple of the prime number.

9. The locking device according to claim 1, wherein, The third set of teeth has a complete gear tooth count n3, which is equal to the complete gear tooth count n1.

10. The locking device according to claim 1, wherein, The fourth set of teeth has a complete gear tooth count n4, which is equal to the complete gear tooth count n2.

11. The locking device according to claim 1, wherein, One of the complete gear teeth n1 and n2 is 56, and the other of the complete gear teeth n1 and n2 is 55.

12. The locking device according to claim 1, wherein, The locking ring is provided with a visual indication of the mutual rotational orientation of the third set of teeth and the fourth set of teeth.

13. The locking device according to claim 12, wherein, The visual indicator is a line that indicates the alignment position of the teeth of the third group of teeth with the teeth of the fourth group of teeth.

14. The locking device according to claim 1, in, Each set of teeth is arranged at different distances from the longitudinal axis of the first connecting member and the second connecting member, wherein: - The first set of teeth is positioned at a distance of D1. - The second set of teeth is positioned at a distance of D2. - The third set of teeth is located at a distance of D3. - The fourth set of teeth is located at a distance of D4. And among them, D3 <D1<D4<D2。 15. The locking device according to claim 2, wherein, The retaining member is in the form of a bolt.

16. A method for connecting and locking a first connecting member and a second connecting member of a locking device according to claim 1, wherein, Before the locking ring is axially moved to the locking position, the locking ring rotates to the lockable orientation in the release position.

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