CN105299159A - Feeding screw tensioning device - Google Patents

Abstract

The present invention relates to a feeding screw tensioning device with high universality and simple structure with no need for arranging an oil supply channel at the side of a drive belt box. The feeding screw tensioning device is configured to push and press an annular driving belt (12) capable of transmitting power through the advance of a push and press body and give tension to the annular driving belt (12). In the feeding screw tensioning device, guidance grooves (24, 25) are installed in the cylindrical wall of the housing of a tensioner of the drive belt box (3c) and are arranged at the outer peripheral face and the inner peripheral face of the at least upper half portion of the feeding screw tensioning device.

Description

Feed screw formula tension device

Technical field

The present invention relates to feed screw formula tension device.

Background technique

Feed screw formula tension device is following tension device: rotary shaft body is rotatably supported on the shaft in stretcher shell, pushing body and rotary shaft body screw thread screw up, and are energized by torsion spring, and rotary shaft body rotates and advances, pushing annular driving band, gives tension force to annular driving band time normal.

The bearing portion that the rotatable earth's axis of rotary shaft body in the stretcher shell of tension device as described above is propped up, is generally and prevents wearing and tearing, needs to supply lubricant oil.

So, have and form the example (with reference to patent documentation 1) that lubricant oil is imported bearing portion by oil duct in the wall of stretcher shell.

[patent documentation 1] Japan Patent No. 4245237 publication

Disclosed in patent documentation 1, feed screw formula tension device ties up to the camshaft drive chain tensioning device in overhead-cam internal-combustion engine, camshaft chain being given to tension force, forms oily passage lubricant oil being imported bearing portion in the wall of stretcher shell.

Also need in the chain tank wall of internal-combustion engine cabinet to be provided with the oil supply gallery be connected with the oil duct of stretcher shell.

Feed screw formula tension device for internal-combustion engine is the common components for multiple pattern internal-combustion engine, but because internal-combustion engine pattern is different, sometimes arrange oil supply gallery spatially to have difficulties, or the reconstruction scope becomes large, result causes adoptable internal-combustion engine pattern limited, there is the problem that versatility is low, cost is high.

Summary of the invention

The present invention puts forward in view of the above problems, its object is to, and provides a kind of and does not need that arrange oil supply gallery, that versatility is high simply constructed feed screw formula tension device in driving belt case side.

For achieving the above object, the invention described in technological scheme 1 is feed screw formula tension device, and it comprises:

Stretcher shell (21), bottomed cylindrical is formed by diapire (22) and cylindrical wall (23), the central shaft (X) of above-mentioned cylindrical wall (23) roughly points to level, is arranged on driving belt case (3c);

Rotary shaft body (30), makes one end rotatably be supported on the shaft on to be formed at the bearing recess (22d) of the bottom surface central authorities of above-mentioned diapire (22);

Pushing body (31), screw up with above-mentioned rotary shaft body (30) screw thread, limited by the guide element (35) being arranged at above-mentioned cylindrical wall (23) opening portion and rotate, simultaneously, axle props up and moves freely into the central shaft (X) in above-mentioned cylindrical wall (23) is upper, by the rotation of above-mentioned rotary shaft body (30), above-mentioned pushing body (31) is in axial advance and retreat; And

Torsion spring (45), to above-mentioned rotary shaft body (30), energizes towards a sense of rotation;

By the annular driving band (12) of the advance pushing transferring power of above-mentioned pushing body (31), time normal to above-mentioned annular driving band (12), give tension force;

In above-mentioned feed screw formula tension device, it is characterized in that:

Among the above-mentioned cylindrical wall (23) of above-mentioned stretcher shell (21) being installed on above-mentioned driving belt case (3c), at outer circumferential face and the inner peripheral surface of at least first half, formed and roughly point to axial oil guide slot (24,25).

The invention that technological scheme 2 is recorded is in the feed screw formula tension device of technological scheme 1 record, it is characterized in that:

Above-mentioned oil guide slot (24, the 25) circumference in above-mentioned cylindrical wall (23), assortment be many adjacent, form continuous print waveform.

The invention that technological scheme 3 is recorded is in the feed screw formula tension device of technological scheme 2 record, it is characterized in that:

The waveform that above-mentioned oil guide slot (24,25) is formed, goes through the all-round formation of cylindrical wall (23).

The invention that technological scheme 4 is recorded is in the feed screw formula tension device recorded in technological scheme 2 or technological scheme 3, it is characterized in that:

The above-mentioned oil guide slot (25) of the inner peripheral surface of above-mentioned cylindrical wall (23), extends until the bottom surface of above-mentioned diapire (22).

The invention that technological scheme 5 is recorded is in the feed screw formula tension device recorded in any one of technological scheme 1 to technological scheme 4, it is characterized in that:

In the bottom surface of above-mentioned diapire (22), form the groove (26) that radiation direction is pointed at Duo Tiaocongzhou center.

The invention that technological scheme 6 is recorded is in the feed screw formula tension device recorded in any one of technological scheme 1 to technological scheme 5, it is characterized in that:

Among above-mentioned cylindrical wall (23), at least first half, from front opening edge to the above-mentioned bearing recess (22d) of above-mentioned diapire (22), form the slit groove (27) towards axially incision.

The invention that technological scheme 7 is recorded is in the feed screw formula tension device recorded in any one of technological scheme 1 to technological scheme 6, it is characterized in that:

The outer circumferential face of above-mentioned cylindrical wall (23) forms conical surface, and make front opening edge from above-mentioned diapire (22) side direction, external diameter diminishes;

The inner peripheral surface of above-mentioned cylindrical wall (23) forms conical surface, makes front opening edge from above-mentioned diapire (22) side direction, and internal diameter becomes large.

The invention that technological scheme 8 is recorded is in the feed screw formula tension device of technological scheme 7 record, it is characterized in that:

Above-mentioned stretcher shell (21) is divided into the mould-forming of two by the axis of the central shaft (X) in above-mentioned cylindrical wall (23).

The invention that technological scheme 9 is recorded is in the feed screw formula tension device recorded in any one of technological scheme 1 to technological scheme 8, it is characterized in that:

By being fitted to the bowl-shape bearing part (40) of the above-mentioned bearing recess (22d) of above-mentioned diapire (22), the rotatable earth's axis in one end of above-mentioned rotary shaft body (30) is propped up;

In the opening end edge of above-mentioned bowl-shape bearing part (40), form multiple otch (41) in circumference.

The invention that technological scheme 10 is recorded is in the feed screw formula tension device of technological scheme 9 record, it is characterized in that:

Rotatably the axial end (30f) that with the bottom surface subtend of above-mentioned bowl-shape bearing part (40) connect of thrust bearing in the shaft end (30d) of the above-mentioned rotary shaft body (30) of above-mentioned bowl-shape bearing part (40), is processed to form as required surface roughness.

The invention that technological scheme 11 is recorded is in the feed screw formula tension device of technological scheme 10 record, it is characterized in that:

The above-mentioned axial end (30f) of above-mentioned rotary shaft body (30) be processed to form for maximum height roughness Rz be more than 7, less than 26 such surface roughnesses.

The invention that technological scheme 12 is recorded is in the feed screw formula tension device recorded in technological scheme 9 or technological scheme 10, it is characterized in that:

In the rotatably axial end (30f) that with the bottom surface subtend of above-mentioned bowl-shape bearing part (40) connect of thrust bearing in the shaft end (30d) of the above-mentioned rotary shaft body (30) of above-mentioned bowl-shape bearing part (40), in the inner side of the edge, periphery (30fe) of this axial end (30f), form oil groove (30v) along this edge, periphery (30fe).

The invention that technological scheme 13 is recorded is in the feed screw formula tension device of technological scheme 12 record, it is characterized in that:

Above-mentioned oil groove (30v) is made up of many arc-shaped oil grooves (30v) split in circumference.

The invention that technological scheme 14 is recorded is in the feed screw formula tension device of technological scheme 13 record, it is characterized in that:

At the shaft end (30d) of above-mentioned rotary shaft body (30), from above-mentioned axial end (30f) along axle center, incision forms the slit locking hole (30e) of locking above-mentioned torsion spring (45) one end;

Above-mentioned arc-shaped oil groove (30v) leaves above-mentioned slit locking hole (30e) formed.

Below, effect of the present invention is described:

According to the feed screw formula tension device that technological scheme 1 is recorded, among the cylindrical wall (23) being installed on the stretcher shell (21) of driving belt case (3c), at outer circumferential face and the inner peripheral surface of at least first half, formed and roughly point to axial oil guide slot (24, 25), therefore, the oil that the inner face being attached to driving belt case (3c) is wandered, run down into the upside outer circumferential face of the cylindrical wall (23) of central shaft (X) the approximate horizontal sensing of stretcher shell (21), simultaneously, the oil dispersed to the upside outer circumferential face of cylindrical wall (23) directly adheres to, arrive the oil of the upside outer circumferential face of cylindrical wall (23), enter the oil guide slot (24) being formed at outer circumferential face, the opening end flowing to cylindrical wall (23) is guided through oil guide slot (24), through this opening end around entering, enter the inner side of cylindrical wall (23), oil guide slot (25) through inner peripheral surface side guides, diapire (22) is arrived along inner peripheral surface, oil supply is supplied well to bearing recess (22d) efficiency being formed at diapire (22), the bearing portion that the rotatable earth's axis in one end of lubricating rotary axis body (30) is propped up, abrasion can be prevented.

Do not need to form oil duct in the wall of stretcher shell (21), simple structure, driving belt case (3c) side does not need to design oil supply gallery yet, so, also restriction can not be produced because type of internal combustion engine is different when being namely used in internal-combustion engine, very high versatility can be maintained, can reduce costs.

According to the feed screw formula tension device that technological scheme 2 is recorded, oil guide slot (24,25) in the circumference of cylindrical wall (23), assortment be many adjacent, form continuous print waveform, therefore, the oil arriving the upside outer circumferential face of cylindrical wall (23) is nearly all directed into many oil guide slot (24,25), can more efficiently to the bearing portion fuel feeding of rotary shaft body (30).

According to the feed screw formula tension device that technological scheme 3 is recorded, by oil guide slot (24,25) waveform formed goes through the all-round formation of cylindrical wall (23), therefore, when making the central shaft of cylindrical wall (23) (X) substantially horizontally be installed on driving belt case (3c) on stretcher shell (21), can no matter cylindrical wall (23) setting angle how, always make oil guide slot (24,25) outer circumferential face and the inner peripheral surface of upside is positioned at, therefore, the installation degrees of freedom of stretcher shell (21) is high, and versatility is improved.

According to the feed screw formula tension device that technological scheme 4 is recorded, the oil guide slot (25) of the inner peripheral surface of cylindrical wall (23), extend until the bottom surface of diapire (22), therefore, through cylindrical wall (23) opening end around the oil entering to enter cylindrical wall (23) inner side, oil guide slot (25) by inner peripheral surface guides, really the bearing recess (22d) being formed at diapire (22) bottom surface is supplied to, can the bearing portion of sufficient lubrication rotary shaft body (30).

According to the feed screw formula tension device that technological scheme 5 is recorded, in the bottom surface of the diapire (22) of stretcher shell (21), form the groove (26) that radiation direction is pointed at Duo Tiaocongzhou center, therefore, if around to the oil of cylindrical wall (23) inner peripheral surface, oil guide slot (25) through inner peripheral surface guides and arrives diapire (22), then guided by the groove (26) being formed at diapire bottom surface radially, concentrate on the bearing recess (22d) of central authorities, the bearing portion efficiency that can concentrate on rotary shaft body (30) supplies oil supply well.

According to the feed screw formula tension device that technological scheme 6 is recorded, among cylindrical wall (23), at at least first half, from front opening edge to the bearing recess (22d) of diapire (22), form the slit groove (27) towards axially incision, therefore, the part arriving the oil of the upside outer circumferential face of cylindrical wall (23) enters slit groove, flow out to the inner peripheral surface of cylindrical wall (23), directly oil can be supplied to the bearing recess (22d) that slit groove (27) is cut, the fuel delivery of the bearing portion to rotary shaft body (30) can be increased.

According to the feed screw formula tension device that technological scheme 7 is recorded, the outer circumferential face of cylindrical wall (23) forms conical surface, make front opening edge from diapire (22) side direction, external diameter diminishes, therefore, promote that the oil of the upside outer circumferential face arriving cylindrical wall (23) flows along conical surface to the opening end of cylindrical wall (23), promote through this opening end around the oil entering to enter cylindrical wall (23) inner side, along the inner peripheral surface diapire side direction front opening edge from cylindrical wall (23), internal diameter becomes the conical surface that the earth is formed, flow to diapire (22), the fuel delivery of the bearing portion to rotary shaft body (30) can be improved.

According to the feed screw formula tension device that technological scheme 8 is recorded, stretcher shell (21) is divided into the mould-forming of two by the axis of the central shaft (X) in cylindrical wall (23), therefore, be shaped by this mould simultaneously and roughly point to axial oil guide slot (24,25), meanwhile, because forming outer circumferential face and the inner peripheral surface of conical surface, axially making to form thin cylindrical wall (23) demoulding of head, be easily shaped.

According to the feed screw formula tension device that technological scheme 9 is recorded, by being fitted to the bowl-shape bearing part (40) of the bearing recess (22d) of the bottom surface central authorities being formed in diapire (22), the rotatable earth's axis in one end of rotary shaft body (30) is propped up, the bearing recess (22d) that stretcher shell (21) is formed directly axle props up rotary shaft body (30), avoid abrasion, make smooth rotation simultaneously, by the opening end edge at bowl-shape bearing part (40), multiple otch (41) is formed in circumference, the bearing portion that oil is supplied to the rotary shaft body (30) as bowl-shape bearing part (40) inner side by otch (41) swimmingly can be passed through.

According to the feed screw formula tension device that technological scheme 10 is recorded, the rotatably axial end (30f) that with the bottom surface subtend of bowl-shape bearing part (40) connect of thrust bearing in the shaft end (30d) of the rotary shaft body (30) of bowl-shape bearing part (40), be processed to form as required surface roughness, therefore, the axial end (30f) with required surface roughness of rotary shaft body (30) is under the state of convex-concave surface oil being remained on this surface roughness, connect with the bottom surface of bowl-shape bearing part (40), carry out thrust bearing.

Therefore, increase due to the surface roughness of the axial end (30f) of rotary shaft body (30) because rotary shaft body (30) rotates produced rotational resistance relative to bowl-shape bearing part (40) relative, because of the lubrication of oil kept at the convex-concave surface of axial end (30f), suppress the increase of above-mentioned rotational resistance, the above-mentioned rotational resistance be inhibited can be maintained, carry out thrust bearing, feed screw mechanism action can be made more reliably, also can suppress the abrasion in thrust-bearing.

According to the feed screw formula tension device that technological scheme 11 is recorded, the axial end (30f) of rotary shaft body (30) be processed to form for maximum height roughness Rz be more than 7, less than 26 such surface roughnesses, therefore, rotary shaft body (30) the maximum height roughness Rz of axial end (30f) be more than 7, the convex-concave surface appropriateness of less than 26 such surface roughnesses keep oil state under, connect with the bottom surface of bowl-shape bearing part (40), carry out thrust bearing.

Therefore, increase due to the surface roughness of the axial end (30f) of rotary shaft body (30) because rotary shaft body (30) rotates produced rotational resistance relative to bowl-shape bearing part (40) relative, because of be more than 7 at the maximum height roughness Rz of axial end (30f), the lubrication of oil that keeps of the convex-concave surface of less than 26 such surface roughnesses, suppress the increase of above-mentioned rotational resistance, the rotational resistance of appropriateness can be maintained, carry out thrust bearing, feed screw mechanism action can be made more reliably, also can suppress the abrasion in thrust-bearing.

When rotary shaft body 30 axial end 30f only machined surface roughness time, when its maximum height roughness Rz is less than 7 or when being greater than 26, because of the relation between surface roughness and oily confining force, be difficult to the rotational resistance obtaining the appropriateness of rotary shaft body 30 in bowl-shape packing ring 40 rotates relatively.

Maximum height roughness Rz is by JISB601:2001 defined.

According to the feed screw formula tension device that technological scheme 12 is recorded, in the rotatably axial end (30f) that with the bottom surface subtend of bowl-shape bearing part (40) connect of thrust bearing in the shaft end (30d) of the rotary shaft body (30) of bowl-shape bearing part (40), in the inner side of the edge, periphery (30fe) of this axial end (30f), oil groove (30v) is formed along this edge, periphery (30fe), therefore, oil groove (30v) leaves edge, periphery (30fe) and is independently formed at axial end (30f), therefore, oil groove (30v) is easy to accumulate oil, the axial end (30f) of rotary shaft body (30) is under the state being made oily appropriateness remain on surface by oil groove (30v), connect with the bottom surface of bowl-shape bearing part (40), carry out thrust bearing.

Therefore, in rotary shaft body (30) in bowl-shape bearing part (40) relative rotates, by keeping oil in axial end (30f) appropriateness, the rotational resistance of appropriateness can be maintained, carry out thrust bearing, feed screw mechanism action can be made more reliably, meanwhile, also can suppress the abrasion of thrust-bearing.

According to the feed screw formula tension device that technological scheme 13 is recorded, above-mentioned oil groove (30v) is made up of many arc-shaped oil grooves split in circumference, therefore, whole surface balance can be gone through in the axial end (30f) of rotary shaft body (30) disperse well and keep oil, in the relative rotation of rotary shaft body (30) relative to bowl-shape bearing part (40), effectively can maintain the rotational resistance of appropriateness, carry out thrust bearing.

According to the feed screw formula tension device that technological scheme 14 is recorded, even if at the shaft end (30d) of rotary shaft body (30), from axial end (30f) along axle center, incision forms slit locking hole (30e) occasion of locking torsion spring (45) one end, arc-shaped oil groove (30v) leaves slit locking hole (30e) and is formed, therefore, arc-shaped oil groove (30v) leaves slit locking hole (30e) and is independently formed at axial end (30f), therefore, arc-shaped oil groove (30v) is easy to long-pending oil, the axial end (30f) of rotary shaft body (30) is passing through oil groove (30v) under surface appropriateness keeps oily state, connect with the bottom surface of bowl-shape bearing part (40), carry out thrust bearing.

Therefore, in the relative rotation of rotary shaft body (30) relative to bowl-shape bearing part (40), the oil of axial end (30f) is remained on by appropriateness, the rotational resistance of appropriateness can be maintained, carry out thrust bearing, feed screw mechanism action can be made more reliably, meanwhile, also can suppress the abrasion of thrust-bearing.

Accompanying drawing explanation

Fig. 1 is the figure of the valve actuation system representing the internal-combustion engine being suitable for the feed screw formula tension device that an example of the present invention relates to.

Fig. 2 represents that this feed screw formula tension device is arranged on the sectional view of the state of drive chain case.

Fig. 3 is the rear view of this feed screw formula tension device.

Fig. 4 is the front elevation of this feed screw formula tension device.

Fig. 5 is the decomposition section of this feed screw formula tension device.

Fig. 6 is the VI-VI direction view of Fig. 5.

Fig. 7 is the VII-VII line sectional view of Fig. 6.

Fig. 8 is the front elevation of cylindrical shell.

Fig. 9 is the front elevation of guide element.

Figure 10 is the amplification stereogram of the rotary shaft body that the 1st variation relates to.

Figure 11 is the amplification stereogram of the rotary shaft body that the 2nd variation relates to.

Figure 12 is the partial enlarged drawing of this rotary shaft body.

Figure 13 is the amplification stereogram of the rotary shaft body that the 3rd variation relates to.

In figure, symbolic significance is as follows:

1-internal-combustion engine

2-crankcase

3-cylinder block

3c-drive chain case

4-cylinder head

5-cowl hood

6-bent axle

10-valve mechanism

11-camshaft

12-camshaft chain (camchain)

13-guide chain part

14-tension slide

15-fulcrum

16-camshaft chain room

20-feed screw formula tension device

21-stretcher shell

22-diapire

22d-bearing recess

23-cylindrical wall

23k-engaging recessed part

24,25,26-oil guide slot

27-slit groove

30-rotary shaft body

30a-outer screw section

30b-screw thread base end part

30c-extension part

30d-fulcrum portion (shaft end)

30e-slit locking hole

30f-axial end

30g-chamfered section

30v-(arc-shaped) oil groove

31-pushes body

32-cylindrical shell

33-covers

34,35-guide element

35a-inserts through hole

35k-engagement pawl

The bowl-shape packing ring of 40-(bowl-shape bearing part)

41-otch

45-disc spring (torsion spring)

46-back-up ring

47-packing ring

48-cylindrical sleeve parts

50-sealing screw

51-O type circle

60-braking clamp stator

Embodiment

Below, the example that the present invention relates to is described based on Fig. 1 to Fig. 9.

The feed screw formula tension device 20 that this example relates to uses as camshaft chain stretcher, the bent axle 6 of SOHC type 4 stroke IC engine 1 that power erects from cylinder by camshaft chain 12 is passed to the camshaft 11 of top, gives tension force when above-mentioned camshaft chain stretcher is normal to camshaft chain 12.

This internal-combustion engine 1 is equipped in vehicle, in this manual, all around towards being set to according to the usual benchmark of vehicle, namely to carry the direction of advance of the vehicle of internal-combustion engine 1 for front.

Fig. 1 is the longitdinal cross-section diagram of the major component of this internal-combustion engine 1.

Prop up on the crankcase 2 of bent axle 6 at axle, overlapping cylinder block 3, cylinder head 4 combine successively, coated cowl hood 5 on cylinder head 4.

The cylinder of cylinder block 3 erects posture in what lean forward a little.

Cylinder head 4 is arranged at by the valve mechanism 10 of the rotary actuation of camshaft 11.

The camshaft 11 being rotatably supported on the shaft on cylinder head 4 and bent axle 6 are disposed in the top of bent axle 6 abreast, driving sprocket wheel 6s is embedded at the left end of bent axle 6, in contrast, be embedded by movable sprocket 11s at the left end of camshaft 11, the camshaft chain 12 as endless belt is erected at driving sprocket wheel 6s and by movable sprocket 11s.

Be set up in driving sprocket wheel 6s and divided by the front side long portion that the long portion of up and down long the front and back extended of the camshaft chain 12 on movable sprocket 11s is divided and led by micro-curved and guide chain part 13 extended in long way, the rear side long portion of the opposing party divides the tension slide 14 of archwise by bending to push from rear.

The lower end of tension slide 14 is supported on the shaft on fulcrum 15 near bent axle 6, the part that extends upward arrange for swing freely.

The camshaft chain room 16 of camshaft chain 12 and guide chain part 13, the through cylinder block 3 of tension slide 14, driving belt case is in the rectangular drum like forming this camshaft chain room 16, at the rear wall 3cr of the drive chain case 3c as above-mentioned driving belt case, this feed screw formula tension device 20 is installed.

The stretcher shell 21 of feed screw formula tension device 20 forms bottomed cylindrical by diapire 22 and cylindrical wall 23, diapire 22 is that Flange-shaped Parts extends from cylindrical wall 23 to peripheral direction, especially, a pair symmetric part extends further, form the flange part 22f of rhombus, screw mounting hole 22fh is formed, 22fh (with reference to Fig. 3, Fig. 4) in the symmetrical extension of flange part 22f.

At the rear wall 3cr of the drive chain case 3c of cylinder block 3, form the circular hole 3ch roughly equal with the external diameter of the cylindrical wall 23 of stretcher shell 21, in order to feed screw formula tension device 20 is installed on drive chain case 3c, outside the rear wall 3cr of drive chain case 3c, the cylindrical wall 23 of stretcher shell 21 is inserted into the circular hole 3ch of rear wall 3cr, by sealed member 71, flange part 22f and rear wall 3cr is abutted against, make screw 70,70 by screw mounting hole 22fh, 22fh is screwed in the rear wall 3cr of drive chain case 3c, is installed into screw type tension device 20.

As shown in Figure 1, the central shaft X of the cylindrical wall 23 of the stretcher shell 21 of feed screw formula tension device 20 is some inclinations, but roughly points to substantially horizontal, is installed on the rear wall 3cr of drive chain case 3c.

Be installed on the feed screw formula tension device 20 of the rear wall 3cr of drive chain case 3c, pushing body 31 is forwards given prominence on central shaft X from the cylindrical wall 23 of stretcher shell 21, and pushing tension slide 14, gives tension force to camshaft chain 12.

Below describe the structure of this feed screw formula tension device 20 in detail.

As front above-mentioned, stretcher shell 21 is made up of the diapire 22 and cylindrical wall 23 possessing flange part 22f, screw 22a is worn in the central authorities of diapire 22, in the open rearward end edge of screw 22a, along the circumferential direction equally spaced carve the locking groove 22k establishing 6 radiation direction, and then, form annular recess 22r in its periphery (with reference to Fig. 3, Fig. 5, Fig. 7).

At annular recess 22r mounting O-shaped rings 51, flanged (FLGD) sealing screw 50 is screwed in screw 22a and carries out closing (with reference to Fig. 2, Fig. 5).

In the front opening edge of the screw 22a of diapire 22 central authorities, form circular recessed bearing recess 22d.

At this bearing recess 22d, embed the bowl-shape packing ring 40 as bearing part.

Bowl-shape packing ring 40 is for having the diapire of hollow, the bowl-shape thrust bearing part in flattened cylinder shape, external diameter is equal with the internal diameter of bearing recess 22d, axial width is identical with the degree of depth of bearing recess 22d, (with reference to Fig. 2 in bowl-shape packing ring 40 embed wholly bearing recess 22d, Fig. 5, Fig. 7).

In order to prevent the bearing recess 22d of the stretcher shell 21 of aluminum from causing abrasion because of direct rotatably thrust bearing rotary shaft body 30 described later, being situated between to have and bowl-shape packing ring 40 made of iron is installed.

The roughly the same diameter of screw 22a of the circular hole 40a of the diapire central authorities of bowl-shape packing ring 40 and diapire 22 central authorities of stretcher shell 21.

In the opening end edge of this bowl-shape packing ring 40, circumferentially form multiple otch 41 (with reference to Fig. 5, Fig. 6).

The cylindrical wall 23 of stretcher shell 21 is forwards given prominence to from diapire 22, and this cylindrical wall 23 is along with the base end part from diapire 22 is to front opening edge, and wall thickness is thinning, forms the sectional shape that front end is thin.

That is, the outer circumferential face of cylindrical wall 23 forms conical surface, and make front opening edge from diapire 22 side direction, external diameter diminishes, and the inner peripheral surface of cylindrical wall 23 forms conical surface, front opening edge from diapire 22 side direction, and internal diameter becomes large.

At outer circumferential face and the inner peripheral surface of the conical surface of this cylindrical wall 23 of formation, circumferentially form multiple oil guide slot 24,25 roughly pointing to the axis (some inclinations) of central shaft X.

Oil guide slot 24,25 in the circumference of cylindrical wall 23, and many adjacent assortments are formed and go through all-round continuous print waveform.

The oil guide slot 25 of the inner peripheral surface of cylindrical wall 23 extends until the bottom surface (with reference to Fig. 5, Fig. 7) of diapire 22.

In the inner side of the cylindrical wall 23 of diapire 22, the ring-type bottom surface in the outside of bearing recess 22d, form many oil guide slot 26 (with reference to Fig. 6) from central shaft X towards radiation direction.

The oil guide slot 26 of this bottom surface is communicated with the oil guide slot 25 of the inner peripheral surface of cylindrical wall 23, and meanwhile, the otch 41 also formed with the bowl-shape packing ring 40 opening end edge place embedding bearing recess 22d is communicated with (with reference to Fig. 2).

In addition, the oil guide slot 26 of bottom surface is formed as the oil guide slot 24 than cylindrical wall 23, and 25 is dark.

In the front opening edge of cylindrical wall 23, the engaging recessed part 23k (with reference to Fig. 5, Fig. 6) that circumferentially equally spaced formation 4 is wide.

Further, at cylindrical wall 23, slit groove 27 to the bearing recess 22d of diapire 22 axially incision, is respectively formed at adjacent engaging recessed part 23k from front opening edge, between 23k (with reference to Fig. 5, Fig. 7).

Slit groove 27 is cut into more than the bottom surface of the bearing recess 22d of diapire 22 (with reference to Fig. 7) deeply.

In the local perforations of the diapire 22 along cylindrical wall 23, form locking hole 23e.

At locking hole 23e, the outboard end 45a of locking aftermentioned disc spring 45.

In addition, at the outer circumferential face of the front opening end of cylindrical wall 23, position set by the axial front of the bottom surface of engaging recessed part 23k, along the circumferential direction all-round formation circumferential groove 23c.

At circumferential groove 23c, be fitted together to back-up ring 46 described later from outside.

In the inside of the cylindrical wall 23 of such stretcher shell 21, at the central shaft X of cylindrical wall 23, arrange rotary shaft body 30 and pushing body 31, above-mentioned rotary shaft body 30 one end is rotatably supported on the shaft on the bearing recess 22d of the bottom surface central authorities being formed in diapire 22, above-mentioned pushing body 31 screws up with this rotary shaft body 30 screw thread, by relative rotation, the central shaft X of cylindrical wall 23 retreats, by the pushing camshaft chain 12 that advances.

With reference to Fig. 5, rotary shaft body 30 is cylindric, and from tip side (forward end), order is coaxial forms outer screw section 30a, screw thread base end part 30b, extension part 30c, fulcrum portion 30d continuously.

Outer screw section 30a is formed as the longest, extension part 30c forms cylindric more some greatly than outer screw section 30a of external diameter, fulcrum portion 30d forms the flattened cylindrical shape that external diameter is larger than extension part 30c, axial width is narrow, in the flattened cylindrical shape of a circle less of the bearing recess 22d of the diapire 22 of stretcher shell 21.

Fulcrum portion 30d in rotary shaft body 30 and extension part 30c, comprise the plane of central shaft until extension part 30c from the rear end axial end 30f edge of the circle forming fulcrum portion 30d, incision forms slit locking hole 30e dearly.

As shown in Figure 2, around the extension part 30c of rotary shaft body 30, arrange the disc spring 45 being wound into scroll, at the slit locking hole 30e of extension part 30c, the inner end 45b of locking disc spring 45.

In addition, the outboard end 45a of disc spring 45, as front above-mentioned, engaging in the locking hole 23e (with reference to Fig. 2) of the cylindrical wall 23 of stretcher shell 21.

Pushing body 31 forms by cylindrical shell 32 with the lid 33 that its front end is riveted.

With reference to Fig. 5 and Fig. 8, the inner peripheral surface of cylindrical shell 32 is carved and is established the female thread 32a screwed up with the outer screw section 30a of rotary shaft body 30, and the outer circumferential face of cylindrical shell 32, by the face truncation of the correspondence of circumferential surface, forms pair of parallel tabular surface 32b, 32b, and its cross section is in the oval shape of distortion.

In addition, the rear end of cylindrical shell 32 retains the circumferential surface 32c of non-truncation.

Guide element 35 limits and rotates, and supports that this cylindrical shell 32 moves axially freely.

With reference to Fig. 5 and Fig. 9, guide element 35 is in plate-like, and central authorities have the insertion through hole 35a of the distortion oval shape identical with the sectional shape of above-mentioned cylindrical shell 32, at peripheral portion, at cross radiation direction outstanding engagement pawl 35k respectively.

4 engagement pawl 35k of guide element 35 engage with 4 engaging recessed part 23k of front opening edge of the cylindrical wall 23 being formed in stretcher shell 21, by the back-up ring 46 of C shape being embedded the circumferential groove 23c of cylindrical wall 23, the movement in the axial direction of restriction guide element 35, prevents come off (with reference to Fig. 2).

As shown in Figure 2, under rotary shaft body 30 and cylindrical shell 32 screw thread of pushing body 31 screw up state, the rear end of the rotary shaft body 30 of one side is rotatably supported on the shaft on the bearing recess 22d of the diapire 22 of stretcher shell 21 by bowl-shape packing ring 40, the insertion through hole 35a of the through guide element 35 of cylindrical shell 32 of the opposing party, limited swivel, moves axially and supports freely.

In addition, the discoideus packing ring 47 of hollow is in the position of the screw thread base end part 30b of rotary shaft body 30, and the side from front with extension part 30c connects, and is situated between to have to install cylindrical sleeve parts 48, the axial position of positioning guide members 35 between this packing ring 47 and guide element 35.

Below, the assembling sequence of the feed screw formula tension device 20 constructed like this based on Fig. 5 simple declaration.

First, bowl-shape packing ring 40 is embedded into stretcher shell 21 diapire 22 bearing recess 22d state under, disc spring 45 is inserted in the cylindrical wall 23 of stretcher shell 21.

The disc spring 45 of scroll makes outermost surface portion connect with the inner peripheral surface close to cylindrical wall 23 bottom surface, makes the outboard end 45a that extends laterally from outermost surface portion engaging in the locking hole 23e of cylindrical wall 23.

In this case, the overwhelming majority of disc spring 45 is from inside winding in outermost surface portion, and central part is hollow, hereinto empty portion, and inner end 45b extends to central authorities.

Rotary shaft body 30 is inserted in cylindrical wall 23, the extension part 30c of rotary shaft body 30 and fulcrum portion 30d is inserted into the hollow portion of disc spring 45, now, the inner end 45b of disc spring 45 is inserted the slit locking hole 30e being formed in extension part 30c and fulcrum portion 30d to carry out locking, and then, bowl-shape packing ring 40 axle that fulcrum portion 30d inserts bearing recess 22d is propped up.

At this, the rotary shaft body 30 being supported on the shaft on bowl-shape packing ring 40 is rotated, winding disc spring 45, during abundant winding, from outside, the braking clamp stator 60 (representing with double dot dash line in figure 3) be made up of one leg and two-arm in T-shaped is inserted the screw 22a of diapire 22, by the front end of one leg engaging in slit locking hole 30e, simultaneously by two-arm engaging in the locking groove 22k being in symmetrical position of outer openings edge being formed in screw 22a, 22k, is set to and forbids by disc spring 45 state that rotary shaft body 30 rotates.

In this case, make packing ring 47 and the through rotary shaft body 30 of cylindrical sleeve parts 48, insert in cylindrical wall 23, then, the cylindrical shell 32 of pushing body 31 is screwed up with the outer screw section 30a screw thread of rotary shaft body 30.

The amount of screwing up is set to initial setting amount in advance.

Then, make the insertion through hole 35a of the oval shape of distortion of the through guide element of cylindrical shell 32 35,4 engagement pawl 35k are made to be sticked in 4 engaging recessed part 23k of the front opening edge of the cylindrical wall 23 being formed in stretcher shell 21, C shape back-up ring 46 is embedded the circumferential groove 23c of cylindrical wall 23, moving axially of restriction guide element 35, installs.

Lid 33 riveted joint is combined in the front end of cylindrical shell 32, makes pushing body 31 integration.

Fulcrum portion, the rear end 30d of rotary shaft body 30 is rotatably supported on the shaft on the bowl-shape packing ring 40 of the bearing recess 22d of diapire 22, and pushing body 31 is forwards given prominence to from the insertion through hole 35a of guide element 35, is axially movably supported in guide element 35.

As above the feed screw formula tension device 20 assembled is under the state being provided with braking clamp stator 60, at the rear wall 3cr of the drive chain case 3c of cylinder block 3, cylindrical wall 23 is inserted circular hole 3ch, by sealed member 71, flange part 22f and rear wall 3cr is abutted against, make screw 70,70 by screw mounting hole 22fh, 22fh, screw up and install (with reference to Fig. 1, Fig. 2) on the rear wall 3cr of drive chain case 3c.

The screw thread amount of screwing up of pushing body 31 relative rotation axi body 30 is set as optimum, and the lid 33 of pushing body 31 is in the state connected with the tension slide 14 being positioned at initial, set position.

At this, if unload braking clamp stator 60, then the spring force of the disc spring 45 reeled just is applied to rotary shaft body 30, rotary shaft body 30 is caused to rotate, the pushing body 31 screwed up with rotary shaft body 30 screw thread advances, and pushes camshaft chain 12 by tension slide 14, gives tension force to camshaft chain 12.

Flanged (FLGD) sealing screw 50 screw thread screws up closed by O type circle 51 by screw 22a in advance that unload the diapire 22 of braking clamp stator 60.

The feed screw formula tension device 20 of such installation, pushing body 31 is screwed up with rotary shaft body 30 screw thread of being energized by disc spring 45, therefore, can not retreat, if produce lax at camshaft chain 12, then because the spring force of disc spring 45 makes rotary shaft body 30 rotate, pushing body 31 is advanced, time normal, gives tension force to camshaft chain 12.

Fig. 2 represents that feed screw formula tension device 20 is installed on the sectional view of the state of the rear wall 3cr of the drive chain case 3c of cylinder block 3.

The oil dispersed because of the rotation of camshaft chain 12, be attached to the internal face of the drive chain case 3c of cylinder head 4 and cylinder block 3, as shown in Figure 2, the oil that the inner face being attached to the rear wall 3cr of drive chain case 3c flows down, runs down into the upside outer circumferential face of the cylindrical wall 23 of the stretcher shell 21 of the feed screw formula tension device 20 given prominence to the inside from rear wall 3cr.

The outer circumferential face of cylindrical wall 23 forms conical surface, it front opening edge from diapire 22 side direction, external diameter diminishes, and upper portion tilts towards front end step-down, simultaneously, oil guide slot 24 is in the adjacent assortment of circumference many of cylindrical wall 23, form continuous print waveform, therefore, the oil running underneath to the upside outer circumferential face of the cylindrical wall 23 of stretcher shell 21 guides through oil guide slot 24, around the engaging recessed part 23k or the front opening edge that enter cylindrical wall 23, enter the inner peripheral surface side of cylindrical wall 23.

In addition, as shown in Figure 2, guide element 35 is located by cylindrical sleeve parts 48, between the bottom surface of engaging recessed part 23k and the engagement pawl 35k of guide element 35, have space, and oil is around to the inner peripheral surface side of cylindrical wall 23.

The inner peripheral surface of cylindrical wall 23 forms conical surface, make to become large from diapire side 22 towards front opening edge internal diameter, upper portion tilts towards diapire 22 side step-down, simultaneously, oil guide slot 25 is in the adjacent assortment of circumference many of cylindrical wall 23, formed until the continuous print waveform of diapire 22 bottom surface, therefore, enter the oil of cylindrical wall 23 inner peripheral surface side towards diapire 22, diapire 22 is flow to along oil guide slot 25, oil is guided to the oil guide slot 26 pointing to radiation direction from axle center that diapire 22 bottom surface is formed, concentrate on the bowl-shape packing ring 40 of the bearing recess 22d of central authorities.

In the opening end edge of bowl-shape packing ring 40, form multiple otch 41 in circumference, therefore, oil can be supplied to the bearing portion of the rotary shaft body 30 inside bowl-shape packing ring 40 by oil swimmingly that concentrate on bowl-shape packing ring 40 by otch 41.

Against the bearing of the rotary shaft body 30 of bowl-shape packing ring 40, supporting radial load and axial load two side, especially, the axial load effect being subject to the axis of the rotary shaft body 30 of the tension force of camshaft chain 12 is very large, therefore, the fuel feeding to the thrust-bearing position connected with the axial end 30f of rotary shaft body 30 and the bottom surface of bowl-shape packing ring 40 is very important.

The oil guide slot 26 of diapire 22 bottom surface is formed as darker than the oil guide slot 24,25 of cylindrical wall 23, therefore, oil can be made in advance to lodge in diapire 22 bottom surface, therefore, stably oil can be supplied to the thrust-bearing position of rotary shaft body 30.

Like this, the oil that the internal face being attached to drive chain case 3c flows down by this feed screw formula tension device 20 imports in the cylindrical wall 23 of stretcher shell 21 efficiently, fully can be supplied to the bearing portion of rotary shaft body 30, prevents abrasion.

Do not need in stretcher shell 21 wall to form oil duct, simple structure, driving belt case 3c side does not need to design oil supply gallery yet, so, also can not produce restriction because type of internal combustion engine is different when being namely used in internal-combustion engine, very high versatility can be maintained, can reduce costs.

With reference to Fig. 6, the feed screw formula tension device 20 of this example is installed on driving belt case 3c, to make in 4 the engaging recessed part 23k formed in the front opening edge of the cylindrical wall 23 of stretcher shell 21 directly over 1 engaging recessed part 23k becomes, therefore, run underneath to the oil of the upside outer circumferential face of the cylindrical wall 23 of stretcher shell 21, from directly over, the directed inflow oil guide slot 24 of oil in the circumferential width of engaging recessed part 23k, flow through the bottom surface of engaging recessed part 23k, around the inner peripheral surface side entering cylindrical wall 23, exceed the directed inflow oil guide slot 24 of oil of the circumferential width left-right parts of engaging recessed part 23k, flow through the front opening end face of cylindrical wall 23, around the inner peripheral surface side entering cylindrical wall 23.

In addition, also can form at the front opening end face of the bottom surface of engaging recessed part 23k and cylindrical wall 23 groove pointing to radiation direction from axle center in advance, by this groove, oil can more swimmingly around the inner peripheral surface side entering cylindrical wall 23.

At cylindrical wall 23, at engaging recessed part 23k, slit groove 27 is had between 23k, therefore, at the first half of cylindrical wall 23,, from front opening edge to the bearing recess 22d of diapire 22, there is the slit groove 27 (with reference to Fig. 6) cut vertically in the left and right sides of the engaging recessed part 23k directly over becoming.

As above above-mentioned, should around the oil of directed inflow oil guide slot 24 entering engaging recessed part 23k or front opening edge, left and right is overflowed, or run underneath to the oil of position of slit groove 27, enter slit groove 27, flow out to the inner peripheral surface of cylindrical wall 23 from slit groove 27, directly oil can be supplied to the bearing recess 22d of incision slit groove 27, the fuel delivery of the bearing portion of the bowl-shape packing ring 40 to supporting rotating shaft body 30 can be increased.

By oil guide slot 24,25 waveforms formed go through the all-round formation of cylindrical wall 23, therefore, when being made by stretcher shell 21 the central shaft X of cylindrical wall 23 substantially horizontally be installed on driving belt case 3c, can no matter cylindrical wall 23 setting angle how, always make oil guide slot 24,25 be positioned at upside outer circumferential face and inner peripheral surface, therefore, the installation degrees of freedom of stretcher shell 21 is high, and versatility is improved.

Stretcher shell 21 is divided into the mould-forming of two by the axis of the central shaft X at cylindrical wall 23, can be shaped by this mould simultaneously and roughly point to axial oil guide slot 24,25, simultaneously, because forming outer circumferential face and the inner peripheral surface of conical surface, axially making to form thin cylindrical wall 23 demoulding of head, be easily shaped.

The present invention is not limited to the example illustrated herein, and such as, oil guide slot 24,25 also can be made up of single groove.

Secondly, as other example, one end is supported on the shaft on the variation of the rotary shaft body 30 of the bowl-shape packing ring 40 of the bearing recess 22d embedding stretcher shell 21, represents at Figure 10 to Figure 13, be described.

Other part except rotary shaft body is identical with the part of the feed screw formula tension device 20 of above-mentioned example, and also shape is identical except axial end for rotary shaft body, therefore, for the part/parts comprising rotary shaft body, adopts same symbol to be illustrated.

Figure 10 represents the 1st variation of rotary shaft body 30.

Fulcrum portion 30d as the shaft end of this rotary shaft body 30 inserts bowl-shape packing ring 40, as radial bearing, simultaneously as thrust-bearing.

The axial load being subject to the axis of the rotary shaft body 30 of the tension force of camshaft chain 12 is large, and therefore, this bowl-shape packing ring 40 is especially large as the effect of thrust-bearing.

The axial end 30f contacted with the bottom surface subtend of the bowl-shape packing ring 40 of the fulcrum portion 30d of rotary shaft body 30 forms circular flat, to peripheral portion chamfering, forms the chamfered section 30g of taper.

At the shaft end 30d of rotary shaft body 30, the slit locking hole 30e of the inner end 45b of locking disc spring 45 cuts formation from axial end 30f along axle center, and thus, the circular flat of axial end 30f is divided into 2 semicircles by slit locking hole 30e.

The axial end 30f of the fulcrum portion 30d of this rotary shaft body 30 is processed to form that the maximum height roughness Rz specified for JISB601:2001 is more than 7, less than 26 such surface roughnesses.

As front above-mentioned, the oil that the inner face being attached to the rear wall 3cr of drive chain case 3c flows down from the outer circumferential face of the cylindrical wall 23 of stretcher shell 21 around entering inner peripheral surface, concentrate on the bowl-shape packing ring 40 of the bearing recess 22d of central authorities, penetrate into the bearing portion of the rotary shaft body 30 inside bowl-shape packing ring 40, lubricating bearings position.

First the oil concentrating on bowl-shape packing ring 40 infiltrate the shaft bearing position of the periphery of the fulcrum portion 30d of rotary shaft body 30, the thrust-bearing position that the axial end 30f then arriving rotary shaft body 30 connects with bowl-shape packing ring 40 bottom surface.

The oil importing to thrust-bearing position is fully held in, and maximum height roughness Rz is more than 7, the convex-concave surface of this surface roughness of the axial end 30f of less than 26 such surface roughnesses.

Like this, under the state that the axial end 30f of rotary shaft body 30 fully keeps oil, connect with the bottom surface of bowl-shape packing ring 40, carry out thrust bearing, therefore, be more than 7 at the maximum height roughness Rz of axial end 30f, the convex-concave surface of less than 26 such surface roughnesses fully can keep oil, because of the lubrication of this oil, suppress to increase due to the surface roughness of the axial end 30f of rotary shaft body 30 because rotary shaft body 30 rotates produced rotational resistance relative to bowl-shape packing ring 40 relative, maintain the rotational resistance of appropriateness, carry out thrust bearing, feed screw mechanism action can be made more reliably.

In addition, the oil by fully keeping also can suppress the abrasion of thrust-bearing.

The maximum height roughness Rz of the axial end 30f of rotary shaft body 30 is than 7 little occasions, and the resistance of rotary shaft body 30 in bowl-shape packing ring 40 relative rotates is natively very little, is difficult to the rotational resistance being obtained appropriateness by oil, and meanwhile, the retentivity of oil also can reduce.

Again, maximum height roughness Rz is large occasion than 26, and the resistance of rotary shaft body 30 in bowl-shape packing ring 40 relative rotates is natively excessive, even if fully keep oil to be also difficult to obtain the rotational resistance of appropriateness.

Secondly, about the 2nd variation of rotary shaft body 30, represent at Figure 11 and Figure 12, be described.

The axial end 30f connected with the bowl-shape packing ring 40 bottom surface subtend of the fulcrum portion 30d of this rotary shaft body 30, identical with the 1st variation, its circular flat is divided into 2 semicircles by slit locking hole 30e, carries out chamfering to peripheral portion, forms the chamfered section 30g of taper.

At the axial end 30f of the fulcrum portion 30d of this rotary shaft body 30, in the inner side of edge, the periphery 30fe of this axial end 30f, form oil groove 30v along this edge, periphery 30fe.

The oil groove 30v of axial end 30f is split by slit locking hole 30e, circumferentially splits further meanwhile, result is divided into 4, the oil groove 30v of segmentation forms mutually same arc-shaped, as the arc-shaped oil groove 30v of 4 same shapes, in circumference to be formed roughly at equal intervals.

In the inner side of edge, the periphery 30fe of the axial end 30f of rotary shaft body 30, circumferentially edge 30fe forms each arc-shaped oil groove 30v, and the end of the slit locking hole 30e side of arc-shaped oil groove 30v is left slit locking hole 30e and is formed, therefore, arc-shaped oil groove 30v and chamfered section 30g departs from, also depart from slit locking hole 30e, be independently formed at axial end 30f.

Therefore, be easy to accumulate oil at each arc-shaped oil groove 30v.

At the axial end 30f of rotary shaft body 30, circumference arrange equably 4 this be easy to accumulate oil arc-shaped oil groove 30v, therefore, on whole of the axial end 30f of rotary shaft body 30, can balance well dispersed oil, keep oil.

Therefore, the axial end 30f of rotary shaft body 30 by 4 arc-shaped oil groove 30v, is contacted with the bottom surface of bowl-shape packing ring 40, forms thrust-bearing under the surface balance state that appropriateness keeps oil well.

That is, in the relative rotation of rotary shaft body 30 relative to bowl-shape packing ring 40, by axial end 30f balance well appropriateness keep oil, the rotational resistance of appropriateness can be maintained, form thrust-bearing, feed screw mechanism action can be made more reliably, meanwhile, the abrasion of thrust-bearing can also be suppressed.

Like this, the rotary shaft body 30 of the 2nd variation forms 4 articles of arc-shaped oil groove 30v at axial end 30f, but the present invention is not limited thereto, such as, 3rd variation is such as shown in fig. 13 that, and the arc-shaped oil groove 30v formed at the axial end 30f of a side split by the slit locking hole 30e of rotary shaft body 30 makes the arc-shaped oil groove 30v of the segmentation in the 2nd variation be communicated with, is set to one article of arc-shaped oil groove 30v.

Therefore, the rotary shaft body 30 of the 3rd variation forms 3 articles of arc-shaped oil groove 30v at axial end 30f, can play same effect with the 2nd variation.

Further, the axial end 30f of rotary shaft body 30 is processed into required surface roughness, meanwhile, also oil groove can be formed at the axial end 30f being processed as required surface roughness.

Above-mentioned above, describe the feed screw formula tension device that the present invention relates to, but form of the present invention has more than and is limited to above-mentioned example, comprises implement with variform in main idea scope of the present invention.

Claims (14)

1. a feed screw formula tension device, comprising:

Stretcher shell (21), bottomed cylindrical is formed by diapire (22) and cylindrical wall (23), the central shaft (X) of above-mentioned cylindrical wall (23) roughly points to level, is arranged on driving belt case (3c);

Rotary shaft body (30), makes one end rotatably be supported on the shaft on to be formed at the bearing recess (22d) of the bottom surface central authorities of above-mentioned diapire (22);

Pushing body (31), screw up with above-mentioned rotary shaft body (30) screw thread, limited by the guide element (35) being arranged at above-mentioned cylindrical wall (23) opening portion and rotate, simultaneously, axle props up and moves freely into the central shaft (X) in above-mentioned cylindrical wall (23) is upper, by the rotation of above-mentioned rotary shaft body (30), above-mentioned pushing body (31) is in axial advance and retreat; And

Torsion spring (45), to above-mentioned rotary shaft body (30), energizes towards a sense of rotation;

By the annular driving band (12) of the advance pushing transferring power of above-mentioned pushing body (31), time normal to above-mentioned annular driving band (12), give tension force;

In above-mentioned feed screw formula tension device, it is characterized in that:

Among the above-mentioned cylindrical wall (23) of above-mentioned stretcher shell (21) being installed on above-mentioned driving belt case (3c), at outer circumferential face and the inner peripheral surface of at least first half, formed and roughly point to axial oil guide slot (24,25).

2., according in the feed screw formula tension device recorded in claim 1, it is characterized in that:

Above-mentioned oil guide slot (24, the 25) circumference in above-mentioned cylindrical wall (23), assortment be many adjacent, form continuous print waveform.

3., according in the feed screw formula tension device recorded in claim 2, it is characterized in that:

The waveform that above-mentioned oil guide slot (24,25) is formed, goes through the all-round formation of cylindrical wall (23).

4., according in the feed screw formula tension device recorded in Claims 2 or 3, it is characterized in that:

The above-mentioned oil guide slot (25) of the inner peripheral surface of above-mentioned cylindrical wall (23), extends until the bottom surface of above-mentioned diapire (22).

5., according in the feed screw formula tension device that in Claims 1 to 4, any one is recorded, it is characterized in that:

In the bottom surface of above-mentioned diapire (22), form the groove (26) that radiation direction is pointed at Duo Tiaocongzhou center.

6., according in the feed screw formula tension device that in Claims 1 to 5, any one is recorded, it is characterized in that:

Among above-mentioned cylindrical wall (23), at least first half, from front opening edge to the above-mentioned bearing recess (22d) of above-mentioned diapire (22), form the slit groove (27) towards axially incision.

7., according in the feed screw formula tension device that in claim 1 ~ 6, any one is recorded, it is characterized in that:

The outer circumferential face of above-mentioned cylindrical wall (23) forms conical surface, and make front opening edge from above-mentioned diapire (22) side direction, external diameter diminishes;

The inner peripheral surface of above-mentioned cylindrical wall (23) forms conical surface, makes front opening edge from above-mentioned diapire (22) side direction, and internal diameter becomes large.

8., according in the feed screw formula tension device recorded in claim 7, it is characterized in that:

Above-mentioned stretcher shell (21) is divided into the mould-forming of two by the axis of the central shaft (X) in above-mentioned cylindrical wall (23).

9., according in the feed screw formula tension device that in claim 1 ~ 8, any one is recorded, it is characterized in that:

By being fitted to the bowl-shape bearing part (40) of the above-mentioned bearing recess (22d) of above-mentioned diapire (22), the rotatable earth's axis in one end of above-mentioned rotary shaft body (30) is propped up;

In the opening end edge of above-mentioned bowl-shape bearing part (40), form multiple otch (41) in circumference.

10., according in the feed screw formula tension device recorded in claim 9, it is characterized in that:

Rotatably the axial end (30f) that with the bottom surface subtend of above-mentioned bowl-shape bearing part (40) connect of thrust bearing in the shaft end (30d) of the above-mentioned rotary shaft body (30) of above-mentioned bowl-shape bearing part (40), is processed to form as required surface roughness.

11., according in the feed screw formula tension device recorded in claim 10, is characterized in that:

The above-mentioned axial end (30f) of above-mentioned rotary shaft body (30) be processed to form for maximum height roughness Rz be more than 7, less than 26 such surface roughnesses.

12., according in the feed screw formula tension device recorded in claim 9 or 10, is characterized in that:

In the rotatably axial end (30f) that with the bottom surface subtend of above-mentioned bowl-shape bearing part (40) connect of thrust bearing in the shaft end (30d) of the above-mentioned rotary shaft body (30) of above-mentioned bowl-shape bearing part (40), in the inner side of the edge, periphery (30fe) of this axial end (30f), form oil groove (30v) along this edge, periphery (30fe).

13., according in the feed screw formula tension device recorded in claim 12, is characterized in that:

Above-mentioned oil groove (30v) is made up of many arc-shaped oil grooves (30v) split in circumference.

14., according in the feed screw formula tension device recorded in claim 13, is characterized in that:

At the shaft end (30d) of above-mentioned rotary shaft body (30), from above-mentioned axial end (30f) along axle center, incision forms the slit locking hole (30e) of locking above-mentioned torsion spring (45) one end;

Above-mentioned arc-shaped oil groove (30v) leaves above-mentioned slit locking hole (30e) formed.