Single-hand focusing handheld thermal imager

Abstract

The utility model discloses a single hand focusing hand-held thermal imager, relates to the imaging equipment technology field, a machine body assembly is provided with a focusing mechanism and a control mechanism, the focusing mechanism comprises a focusing knob, the focusing knob is arranged at one end close to an eyepiece assembly, the part of the focusing knob is exposed at the upper part of the machine body assembly, and the focusing knob is arranged in the forefinger controllable range. The forefinger of the holding hand is used for stirring and rotating so as to drive a machine core mechanism in the machine body assembly to translate along an optical axis to realize focusing, the focusing process is realized by driving of the fingers of the holding hand, the participation of the other hand is not needed, and single-hand focusing is realized; the control mechanism is provided with a plurality of keys, and the keys are arranged on the upper portion of the middle area in the optical axis direction of the machine body assembly, located within the control range of the index finger, the middle finger, the ring finger and the little finger of the holding hand and used for being pressed by the fingers of the holding hand, and single-hand key control can be achieved; the focusing operation and the key operation can be completed by a single hand of a holding hand without the participation of the other hand.

Description

TECHNICAL FIELD

[0001] The utility model relates to imaging equipment technical field, further relates to a single hand focusing hand -held thermal imager. BACKGROUND

[0002] Hand -held observation sighting equipment is usually composed of three main components of front end lens, middle body and rear end ocular lens and is equipped with lens cover, photoelectric sensing assembly, power supply assembly, eyeshade etc.

[0003] The focusing mechanism of the lens is usually arranged near the lens optical mechanism, and the ocular lens diopter adjustment knob is usually arranged near the ocular lens optical mechanism. When the user needs to observe targets at different distances, the lens focal length needs to be adjusted frequently, at this time, one hand holds the equipment, and the other hand operates the lens focusing mechanism and the keys, both hands need to be occupied, which is very inconvenient.

[0004] For those skilled in the art, how to complete the focusing operation and the key operation with one hand is a technical problem to be solved at present. INVENTION CONTENTS

[0005] The core of the utility model is to provide a single hand focusing hand -held thermal imager, which can realize focusing and key operation by fingers of the holding hand, improve use convenience, and the specific scheme is as follows:

[0006] A single hand focusing hand -held thermal imager, comprising an objective lens assembly, a body assembly and an ocular lens assembly, the body assembly is provided with a focusing mechanism and a control mechanism, the focusing mechanism comprises a focusing knob, the focusing knob is located at one end close to the ocular lens assembly, and the focusing knob is partially exposed on the upper part of the body assembly and is used for rotating and driving the core mechanism in the body assembly to translate along the optical axis direction for focusing.

[0007] The control mechanism comprises a circuit board and keys, a plurality of keys are arranged on the circuit board, the keys are arranged on the upper part of the middle region of the body assembly in the optical axis direction and are used for being pressed by fingers of the holding hand.

[0008] Optionally, at least one row of keys is arranged along the optical axis direction, and at least one key is arranged in each row.

[0009] Optionally, at least four keys are arranged at four vertex positions of a rhombus.

[0010] Optionally, the control mechanism comprises a circuit board, and the keys are arranged on the circuit board; the circuit board is fixed in the shell.

[0011] Optionally, the focusing mechanism further comprises a transmission shaft, a focusing seat and a transmission bar, the focusing knob and the transmission shaft are fixed relative to the circumference, the transmission shaft is rotated to drive the focusing seat to translate relative to the main support, and the focusing seat drives the core mechanism to translate through the transmission bar.

[0012] Optionally, the side wall of the transmission shaft is provided with a spiral groove, and a guide pin is arranged on the focusing seat and is slidably inserted into the spiral groove and spirally moves relative to the spiral groove.

[0013] Optionally, the spiral groove is a non-closed groove with a first end not connected to a second end.

[0014] Alternatively, the spiral groove is a closed groove with a first end connected to a second end.

[0015] Optionally, a support seat is arranged on the main support, and a guide groove is arranged on the side wall of the support seat.

[0016] An avoiding channel is arranged on the transmission bar, and at least part of the edge of the avoiding channel is used to be slidably inserted into the guide groove.

[0017] Optionally, the core support of the core mechanism and the objective support of the objective assembly are rectangular frames, and a side pad is arranged between the side wall of the core support and the side wall of the objective support.

[0018] A first sliding pad is arranged between the top surface of the core support and the top surface of the objective support, and a second sliding pad is arranged between the top surface of the objective support and the transmission bar.

[0019] The core support, the first sliding pad, the second sliding pad and the transmission bar are fixed through bolts.

[0020] Optionally, the top surface of the core support is provided with a mounting boss protruding outward, which is used for screwing to fix the first sliding pad, the second sliding pad and the transmission bar.

[0021] The top surface of the objective support is provided with an avoiding notch for avoiding the mounting boss.

[0022] Optionally, the upper part of the main support is provided with a support column protruding upward for supporting the circuit board, and the transmission bar is provided with a leaving hole for avoiding the support column.

[0023] Optionally, a limiting plate is arranged on the main support, and the limiting plate is used for clamping the ring groove arranged on the transmission shaft.

[0024] This utility model relates to a handheld thermal imager with single-handed focusing. The body assembly includes a focusing mechanism and a control mechanism. The focusing mechanism includes a focusing knob located near the eyepiece assembly, with a portion of the knob exposed on the upper part of the body assembly, within the reach of the index finger. The knob is rotated by the index finger of the holding hand, thereby driving the internal mechanism of the body assembly to translate along the optical axis to achieve focusing. The focusing process is driven by the fingers of the holding hand, eliminating the need for the other hand, thus achieving single-handed focusing. The control mechanism includes several buttons located in the upper middle area of ​​the body assembly along the optical axis, within the reach of the index, middle, ring, and little fingers of the holding hand. These buttons are pressed by the fingers of the holding hand, enabling single-handed button operation. Both focusing and button operation can be completed with a single hand, without the need for the other hand. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is an isometric view of the appearance of the single-handed focusing handheld thermal imager of this utility model;

[0027] Figure 2 This is a cross-sectional view of the single-handed focusing handheld thermal imager of this utility model;

[0028] Figure 3 Exploded view of the relevant structures of the fuselage components;

[0029] Figure 4 This is a front view of the first embodiment of the drive shaft;

[0030] Figure 5 This is a front view of a second embodiment of the drive shaft.

[0031] The image includes:

[0032] Objective lens assembly 1, objective lens holder 11, escape gap 111, body assembly 2, focusing mechanism 21, focusing knob 211, transmission shaft 212, spiral groove 2121, ring groove 2122, rolling bearing 2123, sealing ring 2124, focusing seat 213, guide nail 2131, limiting plate 2132, transmission bar 214, escape channel 2141, escape hole 2142, control mechanism 22, circuit board 221, button 222, button cover 223, core mechanism 23, core holder 231, side pad 2311, first sliding pad 2312, second sliding pad 2313, mounting boss 2314, main holder 24, support seat 241, guide groove 2411, support column 242, shell 25, eyepiece assembly 3, eyepiece holder 31, eyeshade 32, diopter adjustment knob 33, battery 4. DETAILED DESCRIPTION

[0033] In order to make the technical personnel in the art better understand the technical scheme of the utility model, the single-hand focusing handheld thermal imager of the utility model will be introduced and explained in detail below in combination with the drawings and specific embodiments.

[0034] The utility model provides a single-hand focusing handheld thermal imager, the single-hand focusing handheld thermal imager can be held by one hand, and focusing operation and button operation are realized by the fingers of the holding hand. Figure 1 、 Figure 2 、 Figure 3 As shown in the drawings, the single-hand focusing handheld thermal imager comprises objective lens assembly 1, body assembly 2, eyepiece assembly 3, battery 4 and the like structure, battery 4 is the power supply of the whole thermal imager, battery 4 is arranged inside body assembly 2; objective lens assembly 1 and eyepiece assembly 3 are arranged at both ends of body assembly 2 respectively, objective lens assembly 1 is the end close to the observed object, eyepiece assembly 3 is the end close to the user, the image signal of the observed object enters from objective lens assembly 1, and can be observed by the user from eyepiece assembly 3 after a series of processing. Eyepiece assembly 3 comprises eyepiece holder 31, eyeshade 32, diopter adjustment knob 33 and the like structure, and diopter adjustment knob 33 is used to adjust eyepiece holder 31 to adapt to different eyesight conditions.

[0035] Body assembly 2 is provided with focusing mechanism 21 and control mechanism 22, focusing mechanism 21 is used for focal length adjustment, and control mechanism 22 is used for button triggering. Focusing mechanism 21 comprises focusing knob 211, focusing knob 211 can rotate around the rotation shaft parallel to the optical axis, and the optical axis refers to the center line of the light beam. When focusing knob 211 is driven to rotate, power is transmitted through the transmission structure, the core mechanism 23 in the inside of body assembly 2 is translated along the optical axis direction, and the focusing action is realized.

[0036] The focusing knob 211 is located near one end of the objective lens assembly 3, and a part of the focusing knob 211 is exposed to the upper part of the shell 25 of the body assembly 2, and the exposed part of the focusing knob 211 can be operated by fingers; when holding the single-hand focusing handheld thermal imager with the holding hand, the focusing knob 211 is within the control range of the index finger of the holding hand, and the focusing knob 211 is used for rotating by the index finger of the holding hand, and the focusing knob 211 can be rotated forward and backward, and the core mechanism 23 inside the shell 25 of the body assembly 2 is driven to translate along the optical axis direction to focus, and the user can adjust the focus by operating the focusing knob 211 with the index finger, so as to observe different distance targets.

[0037] The control mechanism 22 includes a plurality of keys 222, and a key cover 223 is arranged on the shell 25 of the body assembly 2, the key cover 223 is made of elastic material, the key cover 223 covers the keys 222 to prevent water and dust, and the outer surface of the key cover 223 is provided with a concave-convex pattern for providing tactile feedback. The fingers contact the key cover 223 and press the keys 222 downward, and the keys 222 trigger the preset functions when being pressed. The keys 222 are arranged on the upper part of the middle region of the body assembly 2 in the optical axis direction, within the activity range of the index finger, middle finger, ring finger and little finger of the holding hand, and are used for being pressed by the fingers of the holding hand. The keys 222 are arranged on the side of the focusing knob 211 close to the objective lens, and when in use, the index finger of the holding hand can be used to control the focusing knob 211, the thumb is wrapped around the lower part of the single-hand focusing handheld thermal imager to form support, and the other three fingers are used to press the keys 222. The index finger is the most flexible finger, and the focusing knob 211 can be rotated by the index finger to achieve flexible control to the greatest extent. Moreover, the focusing knob 211 and the keys 222 are located above the entire single-hand focusing handheld thermal imager, and can be slightly deviated to one side, so that the fingertips of the index finger can be pressed on the focusing knob 211, the middle finger, ring finger and little finger can be pressed on the keys, and the normal palm holding posture is matched. Not only can the single-hand holding be realized, but also the focusing rotation and key control can be realized by the holding hand, and the focusing operation and key operation can be completed by the holding hand, without the participation of the other hand, which is convenient for the user to use.

[0038] The keys 222 are arranged in at least one row along the optical axis direction, and each row is provided with at least one key 222. The keys 222 are arranged in one row, two rows, three rows or four rows along the optical axis direction, and each row is provided with one or two keys 222. Figure 1 As shown in the figure, four rows of keys 222 are arranged, three rows of which are provided with one key 222 respectively, and one row is provided with two keys 222. Except for the power key, the other four keys 222 form a diamond arrangement, and the total length of the keys arranged along the optical axis direction is shorter, which is more convenient for finger operation. Figure 1In the structure shown, four keys 222 are arranged at the four vertex positions of the rhombus, which can reduce the length along the optical axis direction and make the layout more compact relative to the linear arrangement.

[0039] In combination Figure 3 As shown, the control mechanism of the utility model includes a circuit board 221, the keys 222 are arranged on the circuit board 221, and the circuit board 221 is provided with a printed circuit for transmitting the pressing signals. The circuit board 221 is fixed inside the shell 25, and in combination Figure 2 As shown, the circuit board 221 is located above the focusing mechanism 21 and does not affect the adjustment of the various structures of the focusing mechanism 21.

[0040] In combination Figure 2 , Figure 3 As shown, the focusing mechanism 21 further includes a transmission shaft 212, a focusing seat 213, a transmission bar 214, etc., the focusing knob 211 is fixed relative to the circumference of the transmission shaft 212, the focusing knob 211 and the transmission shaft 212 keep synchronous circumferential rotation, and the rotation shaft is parallel to the optical axis. The focusing seat 213 is slidingly assembled to the main support 24, the focusing seat 213 can move along the optical axis direction, the transmission shaft 212 is rotated to drive the focusing seat 213 to translate relative to the main support 24, the transmission bar 214 is fixedly connected to the focusing seat 213 and the core mechanism 23 respectively, the focusing seat 213 drives the core mechanism 23 to translate through the transmission bar 214, the focusing seat 213, the transmission bar 214 and the core mechanism 23 keep synchronous translational motion, so as to change the distance between the core and the objective lens and realize the focal length adjustment.

[0041] Specifically, in combination Figure 3 As shown, the side wall of the transmission shaft 212 is provided with a spiral groove 2121, the spiral groove 2121 is a spiral groove around the side wall of the transmission shaft 212; the focusing seat 213 is provided with a guide pin 2131, the guide pin 2131 is fixed on the focusing seat 213, the guide pin 2131 keeps synchronous displacement with the focusing seat 213, that is, the guide pin 2131 translates along the optical axis direction with the focusing seat 213; the guide pin 2131 is slidingly inserted into the spiral groove 2121, the guide pin 2131 can spiral move relative to the spiral groove 2121, when the transmission shaft 212 rotates, the guide pin 2131 is pushed by the spiral groove 2121 and can drive the focusing seat 213 to do linear displacement. According to the different rotation directions of the transmission shaft 212, the focusing seat 213 can move along two directions of the straight line, so that the core is close to or away from the objective lens.

[0042] In combination Figure 4 , Figure 5 As shown, the utility model provides two specific setting forms of the transmission shaft 212, the spiral groove 2121 is a non-closed groove with the first end not connected to the second end, or the spiral groove 2121 is a closed groove with the first end connected to the second end. Figure 4The helical groove 2121 shown is a non-closed groove with disconnected ends, the two ends of the helical groove 2121 do not coincide, which is equivalent to a helical line, when the guide pin 2131 reaches the end of the helical groove 2121, it cannot continue to move, but can only reverse the transmission shaft 212 to move the focusing seat 52 in the opposite direction. Figure 5 The helical groove 2121 shown is a closed groove with connected ends, which is equivalent to two helical lines spliced to form, the whole groove is a cycle, which can rotate in one direction all the time, and one rotation is two focusing strokes; the whole helical groove 2121 is axisymmetric, the symmetry plane coincides with the axis line of the transmission shaft 212, and the symmetry plane is Figure 5 The paper surface in the middle, the rear shielding part and the front visible part are axisymmetric. When the guide pin 2131 starts from the farthest point from the objective lens, the transmission shaft 212 rotates forward or reversely by 180° to reach the nearest point; the guide pin 2131 starts from the nearest point from the objective lens, and the transmission shaft 212 rotates forward or reversely by 180° to reach the farthest point. In Figure 5 In the closed groove structure with connected ends shown, the transmission shaft 212 rotates in the same direction, which can continuously adjust the near focus distance → the far focus distance → the near focus distance → the far focus distance ……, forms a cycle, and when focusing, the transmission shaft 212 can be rotated forward and reversely, or continuously rotated in one direction, thereby providing more choices for users.

[0043] As shown in the combination Figure 3 As shown in the combination, the transmission strip 214 is a flat sheet-shaped long strip structure, the avoiding channel 2141 is arranged on the transmission strip 214, at least part of the edge of the avoiding channel 2141 is used for being slidably inserted into the guide groove 2411; one end of the avoiding channel 2141 has a large width, and the rest positions have small widths, which are smaller than the width of the supporting seat 241. The supporting seat 241 is arranged on the main support 24, the side wall of the supporting seat 241 is provided with the guide groove 2411, the vertical height of the guide groove 2411 is slightly greater than the thickness of the transmission strip 214, the edge of the guide groove 2411 can be clamped in, the transmission strip 214 can slide along the guide groove 2411, the guide groove 2411 limits the transmission strip 214 from being twisted, so that the transmission strip 214 moves in a straight line, and the guide groove 2411 serves as a track for the straight-line translation of the transmission strip 214.

[0044] As shown in the combination Figure 3 As shown in the combination, the core support 231 of the core mechanism 23 and the objective lens support 11 of the objective lens assembly 1 are rectangular frames, respectively having left and right two side walls, a top surface and a bottom surface, and since the rectangular frame structure is adopted, the core support 231 and the objective lens support 11 can only move in the optical axis direction and cannot be relatively twisted.

[0045] The side walls of the core support 231 and the side walls of the objective lens support 11 are provided with side pads 2311, which can be made of nylon. The side pads 2311 form a gap between the two side walls of the core support 231 and the two side walls of the objective lens support 11, and play a lubricating role, which can avoid direct contact between the side walls of the core support 231 and the side walls of the objective lens support 11 to cause abrasion.

[0046] The top surface of the core support 231 and the top surface of the objective lens support 11 are provided with a first sliding pad 2312, and the top surface of the objective lens support 11 and the transmission bar 214 are provided with a second sliding pad 2313. The first sliding pad 2312 and the second sliding pad 2313 can be made of nylon. The first sliding pad 2312 plays a spacing role between the top surface of the core support 231 and the top surface of the objective lens support 11, avoids direct contact between the two, and plays a lubricating role. The second sliding pad 2313 forms a gap between the top surface of the objective lens support 11 and the transmission bar 214, and plays a lubricating role. Through the left and right two side pads 2311 and the first sliding pad 2312 and the second sliding pad 2313, the spacing and lubricating roles are played, so that the core support 231 smoothly and smoothly moves along the optical axis direction.

[0047] As shown in the combination Figure 3 The core support 231, the first sliding pad 2312, the second sliding pad 2313, and the transmission bar 214 are fixed by bolts, and the above four are relatively assembled as a whole. The top surface of the objective lens support 11 is clamped between the first sliding pad 2312 and the second sliding pad 2313.

[0048] As shown in the combination Figure 3 The top surface of the core support 231 is provided with a mounting boss 2314, which is a columnar structure. The mounting boss 2314 is used for screwing to fix the first sliding pad 2312, the second sliding pad 2313, and the transmission bar 214. The mounting boss 2314 passes through the first sliding pad 2312 and the second sliding pad 2313, respectively. The top end of the mounting boss 2314 supports the transmission bar 214. The bolt passes through the through hole on the transmission bar 214 and is screwed into the mounting boss 2314 to realize fixed assembly.

[0049] The top surface of the objective lens support 11 is provided with an avoiding gap 111 for avoiding the mounting boss 2314, as shown in Figure 3 There are two mounting bosses 2314, and each mounting boss 2314 is provided with an avoiding gap 111. The width of the avoiding gap 111 is greater than the width of the mounting boss 2314. The mounting boss 2314 moves in the avoiding gap 111 to avoid interference with the movement of the core support 231.

[0050] The upper part of the main support 24 is provided with a support column 242 for supporting the circuit board 221, the support column 242 is provided upwardly protruding and contacts the lower surface of the circuit board 221. The edge of the transmission bar 214 can contact the support column 242 and guide the translation of the transmission bar 214. The transmission bar 214 is provided with a clearance hole 2142 for avoiding the support column 242, at least one support column 242 can pass through the clearance hole 2142, the length of the clearance hole 2142 is greater than the length of the support column 242 along the optical axis direction, and the two cooperate to form a certain guiding effect.

[0051] In combination Figure 3 As shown in the drawings, the main support 24 is provided with a limiting plate 2132, the bottom of the limiting plate 2132 is fixed on the main support 24, the upper part of the limiting plate 2132 is provided with a circular arc notch, the limiting plate 2132 is used for clamping the ring groove 2122 of the transmission shaft 212, the width of the ring groove 2122 is slightly greater than the thickness of the limiting plate 2132, so as to limit the transmission shaft 212 from moving axially and only can rotate. The transmission shaft 212 and the main support 24 can be provided with a rolling bearing 2123 and a sealing ring 2124, the rolling bearing 2123 improves the smoothness of operation, and the sealing ring 2124 can improve the dustproof and waterproof performance.

[0052] The above description of disclosed embodiments enables those skilled in the art to carry out or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A single-handed focus handheld thermal imager, characterized in that, The application relates to a microscope, which comprises an objective assembly (1), a body assembly (2) and an eyepiece assembly (3), wherein the body assembly (2) is provided with a focusing mechanism (21) and a control mechanism (22), the focusing mechanism (21) comprises a focusing knob (211), the focusing knob (211) is located at one end close to the eyepiece assembly (3), and the focusing knob (211) is partially exposed on the upper portion of the shell (25) of the body assembly (2) and used for being rotated by a hand to drive the core mechanism (23) in the shell (25) to translate along the optical axis direction and focus; the control mechanism (22) comprises a button (222), the button (222) is arranged on the upper portion of the middle region of the shell (25) along the optical axis direction and used for being pressed by fingers of the hand.

2. The single-handed focusing handheld thermal imager according to claim 1, characterized in that, At least one row of the buttons (222) is arranged along the optical axis direction.

3. The single-handed focusing handheld thermal imager according to claim 2, characterized in that, At least four buttons (222) are arranged at four vertex positions of a rhombus.

4. The single-handed focusing handheld thermal imager of claim 1, wherein, The control mechanism comprises a circuit board (221), the buttons (222) are arranged on the circuit board (221), and the circuit board (221) is fixed in the shell (25).

5. The single-handed focusing handheld thermal imager according to claim 4, characterized in that, The focusing mechanism (21) further comprises a transmission shaft (212), a focusing seat (213) and a transmission bar (214), the focusing knob (211) and the transmission shaft (212) are fixed in the circumferential direction, the transmission shaft (212) is rotated to drive the focusing seat (213) to translate relative to a main support (24), and the focusing seat (213) drives the core mechanism (23) to translate through the transmission bar (214).

6. The single-handed focusing handheld thermal imager according to claim 5, characterized in that, A spiral groove (2121) is arranged on the side wall of the transmission shaft (212), a guide pin (2131) is arranged on the focusing seat (213), the guide pin (2131) is slidingly inserted into the spiral groove (2121) and spirally moves relative to the spiral groove (2121).

7. The single-handed focusing handheld thermal imager according to claim 6, characterized in that, The spiral groove (2121) is a non-closed groove with disconnected heads. Alternatively, the spiral groove (2121) is a closed groove with connected heads.

8. The single-handed focusing handheld thermal imager according to claim 7, characterized in that, A support seat (241) is arranged on the main support (24), a guide groove (2411) is arranged on the side wall of the support seat (241); An avoiding channel (2141) is arranged on the transmission bar (214), and at least part of the edge of the avoiding channel (2141) is used for slidingly inserting into the guide groove (2411).

9. The single-handed focusing handheld thermal imager according to claim 7, characterized in that, The core support (231) of the core mechanism (23) and the objective support (11) of the objective assembly (1) are rectangular frames, side pads (2311) are arranged between the side walls of the core support (231) and the objective support (11); first sliding pads (2312) are arranged between the top surfaces of the core support (231) and the objective support (11), and second sliding pads (2313) are arranged between the top surface of the objective support (11) and the transmission bar (214); The movement support (231), the first sliding pad (2312), the second sliding pad (2313) and the transmission bar (214) are fixed by bolts.

10. The single-handed focusing handheld thermal imager according to claim 9, characterized in that, The top surface of the movement support (231) is provided with a mounting boss (2314) for screwing to fix the first sliding pad (2312), the second sliding pad (2313) and the transmission bar (214). The top surface of the objective support (11) is provided with an avoiding notch (111) for avoiding the mounting boss (2314).

11. The single-handed focusing handheld thermal imager according to claim 5, characterized in that, The upper part of the main support (24) is provided with a support column (242) for supporting the circuit board (221); the transmission bar (214) is provided with a letting hole (2142) for avoiding the support column (242).

12. The single-handed focusing handheld thermal imager according to claim 5, characterized in that, The main support (24) is provided with a limiting plate (2132), and the limiting plate (2132) is used for clamping the ring groove (2122) of the transmission shaft (212).

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