Coupling structure

Abstract

The present application can easily manage the fastening strength of two cover members. The coupling structure is provided with: a pair of clamping bodies (2a, 3a) respectively arranged on two shafts (2, 3) whose shaft end portions face each other; a ring-shaped rotation transmission body (10) engaged with the teeth of the pair of clamping bodies (2a, 3a); a plurality of cover members (20A, 20B) covering the entire engagement portions of the clamping bodies (2a, 3a) and the rotation transmission body (10); a spacing member (40) arranged between the facing surfaces (24, 24) of the cover members (20A, 20B) facing each other; and a bolt (30) fastening the cover members (20A, 20B) to each other, wherein the coupling structure is provided with a spacing maintaining portion which, when fastened by the bolt (30), limits the distance between the facing surfaces (24, 24) which are prevented from contacting the spacing member (40) to be below a predetermined value.

Description

Technical Field

[0001] This invention relates to coupling construction. Background Technology

[0002] Couplings are used to connect the ends of a pair of shafts to each other. A chain coupling is a type of coupling that consists of locking bodies such as sprockets fixed to each shaft and having teeth arranged circumferentially, and an annular chain having two rows of engaging portions corresponding to the teeth of the sprockets on the two shafts.

[0003] The chain is rotated from the drive side axis to the drive side shaft via two sprockets. At this time, due to the gap between the chain and the sprocket meshing part, rotation is transmitted while allowing the offset of the two shaft axes, buckling of the shaft axes relative to each other, deflection, etc. (for example, see Patent Document 1).

[0004] In the aforementioned coupling, a cover is provided that covers the entire meshing portion of the chain and sprocket. The cover is composed of two cover components. Each cover component includes a semi-cylindrical cylindrical portion and end wall portions that protrude inwards from both ends of the cylindrical portion in the axial direction. Furthermore, flat abutment surfaces are provided at the portions of the two cover components facing each other in the cylindrical portion and the end wall portions.

[0005] Two opposing housing components, separated by a shaft, cover the engagement portion of the coupling from its outer periphery and retain lubricant such as grease within a sealed space inside the housing components. The end wall portion has an arc-shaped sealing portion along the outer periphery of one shaft and an arc-shaped sealing portion along the outer periphery of the other shaft on its inner diameter side edge. The two sealing portions are respectively configured such that the portion of the end wall portion along the outer periphery of the shaft has a groove facing the inner diameter side, and an annular sealing ring fitted into the outer periphery of the shaft is received within this groove. The sealing ring is, for example, an O-ring or a ring-shaped component made of an elastic material such as rubber.

[0006] Furthermore, the opposing cover components are fastened together by bolts to ensure a tight fit. A plate-shaped spacer made of an elastic material such as cork or resin is sandwiched between the abutting surfaces. This spacer prevents the cover components from directly contacting each other and also functions as a seal to prevent internal lubricant from leaking to the outside.

[0007] Patent Document 1: Japanese Patent No. 5728121

[0008] In this type of coupling construction, the degree of tightening strength becomes a problem when the opposing cover components are fastened together. In existing chain coupling constructions, when the cover components are fastened together with bolts, the contact surfaces compress the spacer component while approaching its compression limit. If the contact surfaces are too close together, the spacer component may over-contract and fail to perform its intended cushioning function. Conversely, if the tightening is too weak, the contact between the spacer component and the contact surfaces may be weak, failing to achieve the intended sealing function of the seal. Summary of the Invention

[0009] Therefore, the objective of this invention is to easily manage the fastening strength of the two cover components separated by the spacer.

[0010] To solve the aforementioned problems, the present invention employs a coupling structure (structure 1) comprising: two shafts with their ends facing each other; a pair of locking bodies, each disposed on one of the two shafts, having a plurality of teeth arranged along the axis; an annular rotary transmission body having two rows of engaging portions that mesh with the teeth of the pair of locking bodies; a plurality of cover members covering the entire engaging portion of the locking bodies and the rotary transmission body; a spacer member disposed between the opposing abutment surfaces of the cover members; and bolts for fastening the cover members together with the spacer members spaced between the abutment surfaces. The coupling structure includes a spacer retaining portion, which, when fastened with the bolts, restricts the distance between the abutment surfaces that contact the spacer members to prevent the distance from falling below a predetermined value.

[0011] The present invention employs a coupling structure (structure 2) in which the aforementioned spacing retaining portion consists of a protrusion provided on one side of the opposing abutment surfaces and a recess provided on the other side for the protrusion to enter, wherein the top of the protrusion abuts against the bottom of the recess.

[0012] The present invention employs a coupling structure (structure 3) in which the aforementioned gap holding portion consists of a protrusion provided on one side of the opposing abutment surfaces and a recess provided on the other side for the protrusion to enter, and an outer surface cone formed on the edge of the protrusion abuts against an inner surface cone formed on the edge of the recess.

[0013] Based on any of the structures 1 to 3, the following structure (structure 4) can be adopted, in which the above-mentioned spacer is arranged around the axis of the above-mentioned bolt in the entire circumferential direction.

[0014] Based on any of the structures 1 to 3, the following structure (structure 5) can be adopted, in which the above-mentioned spacing retaining part is provided between one of the above-mentioned bolts and the other above-mentioned bolt.

[0015] The present invention can easily manage the fastening strength of two cover components separated by a spacer. Attached Figure Description

[0016] Figure 1 This is a longitudinal sectional view showing the fixing structure of a coupling cover according to one embodiment of the present invention.

[0017] Figure 2 yes Figure 1 Sectional view II-II.

[0018] Figure 3 yes Figure 1 Sectional view III-III.

[0019] Figure 4 This is a side view showing the cover used for the chain coupling.

[0020] Figure 5 yes Figure 4 VV sectional view.

[0021] Figure 6 yes Figure 4 Sectional view VI-VI.

[0022] Figure 7 This is a top view showing the chain used in the chain coupling.

[0023] Figure 8 yes Figure 7 The main view.

[0024] Figure 9 This is a front view showing the state in which the two cover components constituting the coupling cover are positioned opposite each other with a spacer component between them.

[0025] Figure 10 yes Figure 9 Top view.

[0026] Figure 11 yes Figure 9 The left-side view.

[0027] Figure 12 yes Figure 9 The exploded diagram.

[0028] Figure 13 This is a top view of the spacer component.

[0029] Figure 14 This is an exploded perspective view of the coupling cover.

[0030] Figure 15 This is an enlarged sectional view showing the main parts of the modified example.

[0031] Figure 16 This is an enlarged sectional view showing the main parts of the modified example.

[0032] Figure 17 This is an enlarged sectional view of the main parts, representing a further variation.

[0033] Explanation of reference numerals in the attached figures

[0034] 1...Chain coupling; 2, 3...Shaft; 2a, 3a...Sprocket (locking body); 4...O-ring (sealing ring); 10...Chain (rotary transmission body); 20...Chain and sprocket cover; 20A, 20B...Cover component; 21...Protrusion; 22...Recess; 24...Abutment surface; 30...Bolt; 31...Cylindrical part; 32...End wall part; 40...Spacer component. Detailed Implementation

[0035] Hereinafter, embodiments of the present invention will be described based on the accompanying drawings. The coupling structure of this embodiment is a chain coupling for connecting the ends of two shafts 2 and 3 whose shaft ends are opposite to each other, and includes: a pair of sprockets (locking bodies) 2a and 3a fixed to each shaft 2 and 3, having a plurality of teeth arranged along the axis; and an annular chain (rotational transmission body) 10 having two rows of engaging portions corresponding to the teeth of the sprockets 2a and 3a of the two shafts 2 and 3.

[0036] The chain 10 is connected by two rows of engaging parts that form a single unit, and transmits rotation from the drive-side shaft 2 to the driven-side shaft 3 via two sprockets 2a and 3a. At this time, due to the gap between the engaging parts of the sprockets 2a and 3a and the chain 10, rotation is transmitted while allowing the offset of the axes of the two shafts 2 and 3, the buckling of the axes relative to each other, and the flexing.

[0037] exist Figure 1 In the illustration, sprockets 2a and 3a are shown as a single unit with shafts 2 and 3, but the main bodies of sprockets 2a and 3a and shafts 2 and 3 are usually composed of separate parts. For example, as in Patent Document 1, a structure can be adopted in which shafts 2 and 3 are inserted into a protrusion located at the center of sprockets 2a and 3a, and the main bodies of sprockets 2a and 3a are fixed by screws or the like. Shaft 2 and sprocket 2a, and shaft 3 and sprocket 3a are respectively fixed so that they cannot move relative to each other in the axial direction or around the axis. This pair of sprockets 2a and 3a have the same shape, the same size, and the same circumferential pitch.

[0038] like Figure 1 , Figure 7 as well as Figure 8As shown, chain 10 is a two-row metal roller chain. In this chain 10, two outer plates 11, 11 and one intermediate plate 13 are fitted relative to one pin 14. Additionally, inner plates 12, 12 are fitted around the outer periphery of the pin 14 via bushings 17. Two inner plates 12 are respectively arranged between one outer plate 11 and the intermediate plate 13, and between the other outer plate 11 and the intermediate plate 13. Furthermore, freely rotating rollers 15 are inserted around the outer periphery of the bushings 17.

[0039] An outer plate 11 and an inner plate 12 along the outer plate 11 are arranged alternately (inside and out) along the length of the chain 10. Another outer plate 11 and an inner plate 12 along the outer plate 11 are also arranged alternately (inside and out) along the length of the chain 10. On both sides of the back of the middle plate 13, the inner plates 12 are arranged alternately (inside and out) along the length. The inner plates 12 on both sides of the back of the middle plate 13 are positioned at the same location along the length of the chain 10. Therefore, considering a single pin 14, the arrangement is as follows: one outer plate 11, inner plate 12, roller 15, inner plate 12, middle plate 13, inner plate 12, roller 15, inner plate 12, and another outer plate 11. That is, the chain 10 is a double chain with two rollers 15 arranged in the width direction.

[0040] The two rows of rollers 15 mesh with the teeth of each sprocket 2a, 3a. That is, the engaging part formed by the space between the adjacent pins 14, 14 of the chain 10 and between the inner plates 12, 12 meshes with the teeth of each sprocket 2a, 3a, thereby transmitting rotational torque from the shaft 2 on the driving side to the shaft 3 on the driven side.

[0041] In addition, the coupling structure includes a chain and sprocket cover 20 (hereinafter referred to as cover 20) which uses two cover parts 20A and 20B that cover the entire meshing part of the sprockets 2a and 3a and the chain 10.

[0042] like Figure 1 and Figure 2 As shown, the cover components 20A and 20B each have a semi-cylindrical cylindrical portion 31 and end wall portions 32 protruding inward from both ends of the cylindrical portion 31 in the axial direction. The portions of the cover components 20A and 20B in the cylindrical portion 31 and end wall portions 32 that face each other have flat contact surfaces 24. The internal space enclosed by the cylindrical portion 31 and end wall portions 32 becomes the space that accommodates the entire meshing portion of the sprockets 2a and 3a and the chain 10. In other words, the two-part cover components 20A and 20B cover the entire meshing portion of the sprockets 2a and 3a and the chain 10.

[0043] like Figure 4As shown, the contact surface 24 includes: a parallel portion 24a extending parallel to and of equal width along the end edge of the cylindrical portion 31 and parallel to the shafts 2 and 3; an upright portion 24b rising in the inward diameter direction along the end wall portion 32; and a corner portion 24c between the parallel portion 24a and the upright portion 24b. Bolt holes 26 and 27 are provided in the corner portion 24c for the insertion of bolts 30.

[0044] The end wall portion 32 has an annular sealing ring 4 along the outer periphery of shafts 2 and 3 on its inner diameter side edge (see reference). Figure 1 The groove 28 is used for receiving the material. The groove 28 extends all around the circumference and has a V-shaped cross-section, with its shape gradually becoming shallower from the bottom in the center of its width direction toward both ends. Regarding the raised portion 24b of the abutment surface 24, its inner diameter side end edge faces the groove 28, and the shape of its inner diameter side end edge is the same V-shaped cross-section as the groove 28. Furthermore, in addition to the V-shaped cross-section of the embodiment, the shape of the groove 28 can also be an arc-shaped cross-section or a cross-section resembling the Japanese character "コ".

[0045] like Figure 2 and Figure 3 As shown, the opposing abutment surfaces 24 are fixed to each other in a state of close contact with each other through a plate-shaped spacer 40. At this time, the cover components 20A and 20B, which are separated by shafts 2 and 3, are fixed to each other by bolts 30 inserted into bolt holes 26 and 27 that are open at the corners 24c, in the direction in which the abutment surfaces 24 are close to each other.

[0046] In a cover component 20A, in Figure 4 Separated by shafts 2 and 3, two threaded holes 26, consisting of through holes without threaded grooves, are provided on the upper side, and two bolt holes 27 with internal threads are provided on the lower side. Similarly, in another cover component 20B, as in cover component 20A, two bolt holes 26 (through holes without threaded grooves) and two bolt holes 27 (with internal threads) are provided.

[0047] like Figures 9-12 As shown, one cover component 20A and another cover component 20B are common components. They are arranged in an upside-down configuration so that bolt hole 27 is opposite bolt hole 26. Thus, the threaded portion 30b of bolt 30 passes through bolt hole 26 and is screwed into bolt hole 27. The head 30a of bolt 30 is received in a concave recess 23 provided in the cylindrical portion 31, so as not to protrude outward from the circular outline of cover 20 (see reference). Figure 2 In addition, a concave operating part 30c with a non-circular cross-section (hexagonal cross-section in the embodiment) is provided at the head 30a of the bolt 30. Therefore, if a tool is inserted into the operating part 30c, the bolt 30 can be tightened and loosened.

[0048] One cover component 20A and another cover component 20B are fastened together, with the opposing abutting surfaces 24, 24 of cover components 20A and 20B separated by a spacer component (seal / washer) 40, ensuring a liquid-tight state of the contact area. That is, with the abutting surfaces 24, 24 separated by the spacer component 40, cover components 20A and 20B are fastened together by bolts 30. At the same time, the sealing ring (O-ring) 4 in the groove 28 provides a seal to prevent lubricating oil from leaking out from the sealing portion between the outer periphery of the shafts 2 and 3 and the inner diameter side edge of the end wall portion 32.

[0049] The sealing ring 4 is a ring-shaped component made of rubber, but its material is not limited to rubber; it can also be made of resin.

[0050] The spacer component 40 is made of cork, a material with high heat resistance. The spacer component 40 has a similar material to... Figure 4 The outer edges of the abutment surfaces 24 shown are substantially completely overlapping, forming a plate-like component of the same shape. That is, as... Figure 13 As shown, the structure includes a parallel portion 40a extending parallel to and of equal width along the end edge of the cylindrical portion 31 and parallel to shafts 2 and 3, an upright portion 40b rising in the inner diameter direction along the end wall portion 32, and a corner portion 40c located at the connection between the parallel portion 40a and the upright portion 40b. A bolt-fitting hole 40d is provided in the corner portion 40c. In addition, the shape of the end edge on the inner diameter side of the upright portion 40b is a V-shape, the same shape as the groove 28. Figure 14 This is an exploded perspective view showing the positional relationship between the two spacer members 40 and the cover members 20A and 20B on both sides, which is helpful for understanding the relationship between them.

[0051] As the material for the spacer component 40, various materials that are elastic and can maintain the sealing of the joint can be used. Typically, as in this embodiment, cork material with heat resistance of 200°C or higher is used. However, depending on the operating conditions of the coupling, other materials such as paper, non-woven fabric, or others can also be used.

[0052] In the coupling structure of the present invention, a gap retaining part is provided. When the cover 20 is fastened with bolt 30, the gap retaining part is restricted to prevent the distance between the contact surfaces 24, 24 that contact the gap member 40 from falling below a predetermined value.

[0053] The spacing retaining portion of the embodiment is composed of a protrusion 21 provided on one of the opposing abutment surfaces 24, 24 and a recess 22 provided on the other side and into which the protrusion 21 enters. For example... Figure 5As shown, the height L2 of the protrusion 21 protruding from the abutment surface 24 is greater than the depth L1 of the recess 22 from the abutment surface 24. Therefore, when the opposing cover members 20A and 20B are fastened together, the spacer member 40 and the abutment surface 24 will not be excessively pressed together, and appropriate pressure will be maintained, so that the cushioning function and sealing function will not be impaired due to the spacer member 40.

[0054] Furthermore, in the embodiment, the top (top surface) 21a of the protruding side of the protruding portion 21 and the bottom (bottom surface) 22a of the recess 22 are both composed of flat surfaces, and are configured such that their entire surfaces are in surface contact with each other. Assuming that at least one of the top 21a of the protruding side of the protruding portion 21 and the bottom 22a of the recess 22 is not a flat surface, the protrusion height L2 of the protruding portion 21 and the depth L1 of the recess 22 referred to here are the height L2 of the protruding portion 21 protruding from the contact surface 24 and the depth L1 of the recess 22 from the contact surface 24 at the initial contact position between the top 21a of the protruding side of the protruding portion 21 and the bottom 22a of the recess 22 when the opposing cover members 20A and 20B are brought close to each other and the protruding portion 21 enters the recess 22.

[0055] Here, if the thickness of the spacer 40 before fastening (before use) is set as t0, and the thickness under appropriate pressure is set as t1, then it is preferable to...

[0056] L2-L1=t1 … (Equation 1).

[0057] If the allowable error is α, then it is

[0058] t1+α>L2-L1>t1-α... (Formula 2).

[0059] In addition, requirements

[0060] t0>L2-L1 … (Equation 3).

[0061] In this way, the spacer retaining part is provided in the cover 20, thereby eliminating excessive tightening and insufficient tightening, and thus the tightening strength of the two cover parts 20A and 20B separated by the spacer member 40 can be easily managed.

[0062] In this embodiment, the spacer retainer is arranged around the axis of the bolt 30 throughout the entire circumference. Specifically, the protrusion 21 and recess 22 constituting the spacer retainer are respectively provided around the bolt holes 26 and 27 of the cover members 20A and 20B. Therefore, it is easy to ensure proper pressing pressure on the spacer member 40 around the bolt 30, which is prone to over-tightening. In particular, in this embodiment, the protrusion 21 and recess 22 have circular cross-sections, and the centers of the circular cross-section protrusion 21 and recess 22 are located on the axis of the bolt 30 (the axis of the bolt holes 26 and 27), thus further reliably ensuring proper pressing pressure around the bolt 30.

[0063] In one embodiment, the spacer retainer is arranged around the axis of the bolt 30 in the entire circumferential direction, but the position of the spacer retainer is not limited to this embodiment. For example, the spacer retainer may also be arranged away from the bolt 30. That is, it is also possible to arrange the spacer retainer away from the bolt holes 26, 27, for example, between one bolt 30 (one bolt hole 26) and another bolt 30 (another bolt hole 26) or between one bolt 30 (one bolt hole 27) and another bolt 30 (another bolt hole 27).

[0064] Figure 15 and Figure 16 This illustrates a modified example of the spacer retaining portion. In this modified example, the spacer retaining portion is configured such that the top 21a of the protrusion 21 does not abut against the bottom 22a of the recess 22, but instead, the outer surface cone 21b formed on the edge of the protrusion 21 abuts against the inner surface cone 22b formed on the edge of the recess 22. In this embodiment, the outer surface cone 21b is provided around the entire circumference of the edge of the protrusion 21, and the inner surface cone 22b is provided around the entire circumference of the edge of the recess 22, but it may also be provided on a portion of each edge.

[0065] The outer surface cone 21b and the inner surface cone 22b make surface contact, thereby facilitating the alignment of the opposing cover components 20A and 20B. The effects of preventing over-tightening, preventing under-tightening, and facilitating the management of tightening strength provided by the spacer are the same as those in the embodiment described above.

[0066] Here, in Figure 15 and Figure 16 In the modified example shown, when the outer surface cone 21b and the inner surface cone 22b are in surface contact and cannot be further tightened, the top 21a of the protrusion 21 and the bottom 22a of the recess 22 do not abut. In this configuration, the height L2 of the protrusion 21 protruding from the abutment surface 24 and the depth L1 of the recess 22 from the abutment surface 24 can be freely set.

[0067] In addition, Figure 17 In a further variation shown, the outer surface tapered portion 21b formed on the edge of the protrusion 21 abuts against the inner surface tapered portion 22b formed on the edge of the recess 22, and when a predetermined tightness is achieved, the top 21a of the protrusion 21 abuts against the bottom 22a of the recess 22. In this case, if the thickness of the spacer member 40 under appropriate pressure is set to t1, and an error α is allowed, then the requirement is...

[0068] t1+α>L2-L1>t1-α... (Formula 2).

[0069] exist Figure 17In the modified example shown, the shapes of the outer surface cone 21b and the inner surface cone 22b are also similar to... Figure 15 and Figure 16 The variations shown are the same.

[0070] In the above embodiments, the cover components 20A and 20B are composed of components of the same shape and size, but it is not excluded that the two may have different shapes and sizes. The cover 20 is composed of two cover components 20A and 20B, but it may also be composed of three or more cover components 20A, 20B, 20C, etc.

[0071] In existing coupling designs, situations may arise where the spacer member 40 excessively shrinks due to over-tightening of the opposing cover members 20A and 20B, or conversely, insufficient tightening prevents it from fulfilling its intended sealing function. However, according to the present invention, a spacer retaining portion is provided to limit the distance between the contact surfaces 24, 24 that contact the spacer member 40 to a predetermined value, thus making it easy to manage the tightening strength. That is, the thickness and tightness of the tightened spacer member (seal / gasket) 40 are easily managed.

[0072] Furthermore, in existing coupling designs, there is a problem that alignment is difficult when fastening opposing cover components 20A and 20B together. Conventionally, alignment is performed by feeling with the fingertips and visual inspection, using the clearance between the outer circumference of the fastening bolt and the inner surface of the mounting hole as a reference. However, according to the present invention, alignment is easily achieved by fitting the protrusions 21 of the opposing cover components 20A and 20B into the recesses 22, thus reducing the time and effort required for the operation and improving the precision of the finishing process.

Claims

1. A coupling structure, characterized in that, have: Two shafts (2, 3), with their ends facing each other; A pair of locking bodies (2a, 3a) are respectively disposed on the two shafts (2, 3) and have multiple teeth arranged along the axis direction; The annular rotary transmission body (10) has two rows of engaging portions that mesh with the teeth of the paired locking bodies (2a, 3a); Multiple cover components (20A, 20B) cover the entire engagement portion of the locking body (2a, 3a) and the rotary transmission body (10); Spacer members (40) are disposed between the opposing abutment surfaces (24) of the cover members (20A, 20B); and Bolts (30) are used to fasten the cover components (20A, 20B) together with the spacer member (40) between the abutting surfaces (24, 24). The coupling is configured with a spacing retaining part, which restricts the distance between the contact surfaces (24, 24) that contact the spacing member (40) to a predetermined value when the coupling is tightened using the bolt (30).

2. The coupling structure according to claim 1, characterized in that, The spacer is a protrusion (21) provided on one side of the opposing abutment surfaces (24, 24) and a recess (22) provided on the other side for the protrusion (21) to enter, wherein the top (21a) of the protrusion (21) abuts against the bottom (22a) of the recess (22).

3. The coupling structure according to claim 1, characterized in that, The spacer is a protrusion (21) provided on one side of the opposing abutment surfaces (24, 24) and a recess (22) provided on the other side for the protrusion (21) to enter. The outer surface cone (21b) formed on the edge of the protrusion (21) abuts against the inner surface cone (22b) formed on the edge of the recess (22).

4. The coupling structure according to any one of claims 1 to 3, characterized in that, The spacer is positioned around the axis of the bolt (30) in the entire circumferential direction.

5. The coupling structure according to any one of claims 1 to 3, characterized in that, The spacer is positioned between one of the bolts (30) and the other bolt (30).

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