CN105299159B - Feed screw formula tensioning apparatus - Google Patents

Abstract

The present invention relates to feed screw formula tensioning apparatus.Its problem is, there is provided the feed screw formula tensioning apparatus of simple structure that set oil supply gallery, that versatility is high is not required in transmission belt case side.Advance of the screw tensioning apparatus by pushing body (31) pushes the annular driving band (12) of passing power, tension force is given during to annular driving band (12) often, in the feed screw formula tensioning apparatus, it is installed among the cylindrical wall (23) of the stretcher shell (21) of transmission belt case (3c), in the outer peripheral face and inner peripheral surface of at least first half, formation is pointed generally in axial oil guide groove (24,25).

Description

Feed screw formula tensioning apparatus

Technical field

The present invention relates to feed screw formula tensioning apparatus.

Background technology

Feed screw formula tensioning apparatus is following tensioning apparatus：Rotary shaft body is rotatably supported on the shaft on stretcher shell It is interior, push body and screwed up with rotary shaft body screw thread, energized by torsion spring, rotary shaft body rotates and advanced, and pushes annular driving band, often When give tension force to annular driving band.

Rotary shaft body in the stretcher shell of tensioning apparatus as described above rotates freely the bearing portion of earth's axis branch, Usually prevent abrasion, it is necessary to supply lubricating oil.

Then, have and example (the reference patent that oil duct imports lubricating oil bearing portion is formed in the wall of stretcher shell Document 1).

【Patent document 1】No. 4245237 publications of Japanese Patent No.

Feed screw formula tensioning apparatus is tied up in overhead-cam internal combustion engine to camshaft chain disclosed in patent document 1 The camshaft drive chain tension means of tension force are given, the oil that lubricating oil is imported to bearing portion is formed in the wall of stretcher shell Passage.

It is also required to be provided with the oil supply gallery being connected with the oil duct of stretcher shell in the chain tank wall of internal combustion engine cabinet.

Feed screw formula tensioning apparatus for internal combustion engine is the common components for a variety of pattern internal combustion engines, but because of internal combustion Type formula is different, sets oil supply gallery spatially to have difficulties sometimes, or the reconstruction scope becomes big, as a result causes in adoptable Combustion engine pattern is limited, and the problem that versatility is low, cost is high be present.

The content of the invention

The present invention puts forward in view of the above problems, its object is to, there is provided one kind is not required to set in transmission belt case side The feed screw formula tensioning apparatus of simple structure that put oil supply gallery, that versatility is high.

To reach above-mentioned purpose, the invention described in technical scheme 1 is feed screw formula tensioning apparatus, and it includes：

Stretcher shell 21, bottomed cylindrical is formed by bottom wall 22 and cylindrical wall 23, the central shaft X of above-mentioned cylindrical wall 23 is big Cause to point to level, installed in transmission belt case 3c；

Rotary shaft body 30 so that one end is rotatably supported on the shaft on the bearing in the bottom surface center for being formed at above-mentioned bottom wall 22 Recess 22d；

Body 31 is pushed, is screwed up with the above-mentioned screw thread of rotary shaft body 30, by the guide portion for being arranged at the above-mentioned opening portion of cylindrical wall 23 The limitation rotation of part 35, meanwhile, axle branch is that movement freely, passes through above-mentioned rotary shaft body 30 on the central shaft X of above-mentioned cylindrical wall 23 Rotation, above-mentioned pushing body 31 is in axial advance and retreat；And

Torsion spring 45, to above-mentioned rotary shaft body 30, energized towards a direction of rotation；

The annular driving band 12 of passing power is pushed by the advance of above-mentioned pushing body 31, it is normal to above-mentioned annular driving band 12 When give tension force；

In above-mentioned feed screw formula tensioning apparatus, it is characterised in that：

It is installed among the above-mentioned cylindrical wall 23 of above-mentioned transmission belt case 3c above-mentioned stretcher shell 21, at least upper half The outer peripheral face and inner peripheral surface in portion, formation are pointed generally in axial oil guide groove 24,25.

The invention that technical scheme 2 is recorded is that its feature exists in the feed screw formula tensioning apparatus that technical scheme 1 is recorded In：

Above-mentioned oil guide groove 24,25 above-mentioned cylindrical wall 23 circumference, it is a plurality of adjacent with being classified as, form continuous waveform.

The invention that technical scheme 3 is recorded is that its feature exists in the feed screw formula tensioning apparatus that technical scheme 2 is recorded In：

The waveform that above-mentioned oil guide groove 24,25 is formed, the all-round formation after cylindrical wall 23.

The invention that technical scheme 4 is recorded is the feed screw formula tensioning apparatus in technical scheme 2 or the record of technical scheme 3 In, it is characterised in that：

The above-mentioned oil guide groove 25 of the inner peripheral surface of above-mentioned cylindrical wall 23, extend up to the bottom surface of above-mentioned bottom wall 22.

The invention that technical scheme 5 is recorded is the feed screw formula in any one record of technical scheme 1 to technical scheme 4 In tight device, it is characterised in that：

In the bottom surface of above-mentioned bottom wall 22, a plurality of groove 26 that radiation direction is pointed to from axis center is formed.

The invention that technical scheme 6 is recorded is the feed screw formula in any one record of technical scheme 1 to technical scheme 5 In tight device, it is characterised in that：

It is recessed at least first half, the above-mentioned bearing from front opening edge to above-mentioned bottom wall 22 among above-mentioned cylindrical wall 23 Portion 22d, formed towards the slit groove 27 axially cut.

The invention that technical scheme 7 is recorded is the feed screw formula in any one record of technical scheme 1 to technical scheme 6 In tight device, it is characterised in that：

The outer peripheral face of above-mentioned cylindrical wall 23 forms circular conical surface so that from above-mentioned bottom wall 22 it is lateral front opening edge, outside Footpath diminishes；

The inner peripheral surface of above-mentioned cylindrical wall 23 forms circular conical surface so that from above-mentioned bottom wall 22 it is lateral front opening edge, it is interior Footpath becomes big.

The invention that technical scheme 8 is recorded is that its feature exists in the feed screw formula tensioning apparatus that technical scheme 7 is recorded In：

Above-mentioned stretcher shell 21 by be divided into the axial direction of the central shaft (X) of above-mentioned cylindrical wall 23 two mould molding.

The invention that technical scheme 9 is recorded is the feed screw formula in any one record of technical scheme 1 to technical scheme 8 In tight device, it is characterised in that：

Pass through the bowl-shape parts of bearings 40 for the above-mentioned bearing recess 22d for being fitted to above-mentioned bottom wall 22, above-mentioned rotary shaft body 30 One end rotate freely the earth's axis and prop up；

In the opening end edge portion of above-mentioned bowl-shape parts of bearings 40, multiple otch 41 are circumferentially being formed.

The invention that technical scheme 10 is recorded is that its feature exists in the feed screw formula tensioning apparatus that technical scheme 9 is recorded In：

Rotatably thrust bearing is in the shaft end 30d of the above-mentioned rotary shaft body 30 of above-mentioned bowl-shape parts of bearings 40 With the bottom surface of above-mentioned bowl-shape parts of bearings 40 to being formed as required surface roughness to the axial end 30f to connect, processing.

The invention that technical scheme 11 is recorded is that its feature exists in the feed screw formula tensioning apparatus that technical scheme 10 is recorded In：

The above-mentioned axial end 30f processing of above-mentioned rotary shaft body 30 is formed as maximum height roughness Rz as more than 7, less than 26 Such surface roughness.

The invention that technical scheme 12 is recorded is the feed screw formula tensioning apparatus in technical scheme 9 or the record of technical scheme 10 In, it is characterised in that：

In shaft end 30d of the rotatably thrust bearing in the above-mentioned rotary shaft body 30 of above-mentioned bowl-shape parts of bearings 40 With the bottom surface of above-mentioned bowl-shape parts of bearings 40 to the axial end 30f to connect, in axial end 30f periphery edge 30fe Inner side, oil groove 30v is formed along periphery edge 30fe.

The invention that technical scheme 13 is recorded is that its feature exists in the feed screw formula tensioning apparatus that technical scheme 12 is recorded In：

Above-mentioned oil groove 30v in a plurality of arc-shaped oil groove 30v circumferentially split by forming.

The invention that technical scheme 14 is recorded is that its feature exists in the feed screw formula tensioning apparatus that technical scheme 13 is recorded In：

In the shaft end 30d of above-mentioned rotary shaft body 30, locking above-mentioned torsion is cut into from above-mentioned axial end 30f along axis center The slit locking hole 30e of the one end of spring 45；

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

Below, the effect of the present invention is illustrated：

The feed screw formula tensioning apparatus recorded according to technical scheme 1, it is installed on transmission belt case 3c stretcher shell 21 Cylindrical wall 23 among, in the outer peripheral face and inner peripheral surface of at least first half, formation is pointed generally in axial oil guide groove 24,25, because This, is attached to the oil that transmission belt case 3c inner face is wandered, and runs down into central shaft (X) approximate horizontal sensing of stretcher shell 21 Cylindrical wall 23 upside outer peripheral face, meanwhile, disperse to cylindrical wall 23 upside outer peripheral face oil directly attachment etc., reach cylinder The oil of the upside outer peripheral face of wall 23, into the oil guide groove 24 for being formed at outer peripheral face, cylindrical wall 23 is flowed to through the guiding of oil guide groove 24 Openend, through the openend around entering, into the inner side of cylindrical wall 23, the oil guide groove 25 through inner peripheral surface side is guided, arrived along inner peripheral surface Up to bottom wall 22, oil, one end rotation of lubricating rotary axis body 30 are supplied well to the bearing recess 22d efficiency for being formed at bottom wall 22 The bearing portion of earth's axis branch freely, can prevent from wearing away.

It is not required to form oil duct, simple structure in the wall of stretcher shell 21, transmission belt case 3c sides are also not required to design fuel feeding Passage, so, that is, also will not be different because of type of internal combustion engine when being used in internal combustion engine and produce limitation, can remain very high general Property, cost can be reduced.

The feed screw formula tensioning apparatus recorded according to technical scheme 2, oil guide groove 24,25 are matched somebody with somebody in the circumference of cylindrical wall 23 It is classified as a plurality of adjacent, forms continuous waveform, therefore, the oil for reaching the upside outer peripheral face of cylindrical wall 23 is nearly all directed into A plurality of oil guide groove 24,25, can be more efficiently to the bearing portion fuel feeding of rotary shaft body 30.

The feed screw formula tensioning apparatus recorded according to technical scheme 3, the waveform formed by oil guide groove 24,25 is after cylinder The all-round formation of wall 23, therefore, when by stretcher shell (21) cause cylindrical wall 23 central shaft X be mounted substantially horizontally on biography During dynamic band case 3c, can regardless of the setting angle of cylindrical wall 23, total outer peripheral face for causing oil guide groove 24,25 to be located at upside and Inner peripheral surface, therefore, the installation free degree of stretcher shell 21 is high, and versatility is improved.

The feed screw formula tensioning apparatus recorded according to technical scheme 4, the oil guide groove 25 of the inner peripheral surface of cylindrical wall 23, extension Until the bottom surface of bottom wall 22, therefore, through the openend of cylindrical wall 23 around the oil entered on the inside of cylindrical wall 23 is entered, by the Oil Guide of inner peripheral surface Groove 25 guides, and supply really, can be with the bearing of sufficient lubrication rotary shaft body 30 to the bearing recess 22d for being formed at the bottom surface of bottom wall 22 Position.

The feed screw formula tensioning apparatus recorded according to technical scheme 5, in the bottom surface of the bottom wall 22 of stretcher shell 21, shape Into it is a plurality of from axis center point to radiation direction groove 26, therefore, if around to the oil of the inner peripheral surface of cylindrical wall 23, leading through inner peripheral surface Oil groove 25 is directed to up to bottom wall 22, then is guided by the groove 26 for being radially formed at bottom wall bottom surface, and the bearing for concentrating on center is recessed Portion 22d, the bearing portion efficiency that can concentrate on rotary shaft body 30 supply oil well.

The feed screw formula tensioning apparatus recorded according to technical scheme 6, among cylindrical wall 23, at least first half, in the past End opening edge forms towards the slit groove 27 axially cut to the bearing recess 22d of bottom wall 22, therefore, reaches cylindrical wall 23 Oil, directly can be supplied to narrow by the oily inner peripheral surface for being partly into slit groove, flowing out to cylindrical wall 23 of upside outer peripheral face The bearing recess 22d that slot 27 is cut, the fuel delivery of the bearing portion to rotary shaft body 30 can be increased.

The feed screw formula tensioning apparatus recorded according to technical scheme 7, the outer peripheral face of cylindrical wall 23 form circular conical surface so that From bottom wall 22 it is lateral front opening edge, external diameter diminish, therefore, promote to reach the oil of the upside outer peripheral face of cylindrical wall 23 along Circular cone flows towards the openend of cylindrical wall 23, promotes through the openend around entering to enter the oil of the inner side of cylindrical wall 23, along from circle The lateral front opening edge of inner peripheral surface bottom wall of barrel 23, internal diameter become the circular conical surface that the earth is formed, and are flowed to bottom wall 22, Ke Yiti The fuel delivery of the high bearing portion to rotary shaft body 30.

The feed screw formula tensioning apparatus recorded according to technical scheme 8, stretcher shell 21 is by the center of cylindrical wall 23 Axle X axial direction is divided into two mould molding, and axial oil guide groove 24 is pointed generally in accordingly, it is capable to be shaped by the mould simultaneously, 25, meanwhile, because forming the outer peripheral face and inner peripheral surface of circular conical surface, it can axially make it that forming the thin cylindrical wall 23 of head is stripped, easily Shaping.

The feed screw formula tensioning apparatus recorded according to technical scheme 9, to be formed in the bottom surface of bottom wall 22 by being fitted to The bearing recess 22d of centre bowl-shape parts of bearings 40, one end of rotary shaft body 30 rotate freely the earth's axis and propped up, stretcher shell The 21 direct axle branch rotary shaft bodies 30 of bearing recess 22d formed, avoid wearing away, while make smooth rotation, by bowl-shape bearing The opening end edge portion of part 40, multiple otch 41 are circumferentially being formed, can be smoothly supplied to oil by otch 41 be used as bowl The bearing portion of the rotary shaft body 30 of the inner side of shape parts of bearings 40.

The feed screw formula tensioning apparatus recorded according to technical scheme 10, rotatably thrust bearing is in bowl-shape bearing portion In the shaft end 30d of the rotary shaft body 30 of part 40 with the bottom surface of bowl-shape parts of bearings 40 to the axial end 30f to connect, processing Be formed as required surface roughness, therefore, the axial end 30f with required surface roughness of rotary shaft body 30 is being incited somebody to action Oil is maintained in the state of the convex-concave surface of the surface roughness, is connected with the bottom surface of bowl-shape parts of bearings 40, carries out thrust branch Hold.

Therefore, because of rotary shaft body 30 relative to rotational resistance caused by the rotating against of bowl-shape parts of bearings 40 due to rotation The axial end 30f of axis body 30 surface roughness and increase, because axial end 30f convex-concave surface holding oily lubrication, suppression The increase of above-mentioned rotational resistance is made, the above-mentioned rotational resistance being inhibited can be maintained, thrust bearing is carried out, can more reliably cause Feed screw mechanism action, it can also suppress the abrasion in thrust bearing.

The feed screw formula tensioning apparatus recorded according to technical scheme 11, the axial end 30f of rotary shaft body 30 process to be formed It is more than 7, less than 26 such surface roughnesses for maximum height roughness Rz, therefore, rotary shaft body 30 is axial end 30f's In the state of maximum height roughness Rz moderately keeps oil for the convex-concave surface of more than 7, less than 26 such surface roughnesses, with The bottom surface of bowl-shape parts of bearings 40 connects, and carries out thrust bearing.

Therefore, because of rotary shaft body 30 relative to rotational resistance caused by the rotating against of bowl-shape parts of bearings 40 due to rotation The axial end 30f of axis body 30 surface roughness and increase, because axial end 30f maximum height roughness Rz be more than 7,26 The oily lubrication that the convex-concave surface of such surface roughness is kept below, suppresses the increase of above-mentioned rotational resistance, can remain suitable The rotational resistance of degree, thrust bearing is carried out, can more reliably cause feed screw mechanism action, can also suppress in thrust bearing Abrasion.

When the axial end 30f only machined surface roughnesses of rotary shaft body 30, when its maximum height roughness Rz is less than 7 Or during more than 26, because of the relation between surface roughness and oily confining force, it is difficult to obtain the relatively bowl-shape packing ring 40 of rotary shaft body 30 Appropriate rotational resistance in rotating against.

Rz is by JISB601 for maximum height roughness：2001 defineds.

The feed screw formula tensioning apparatus recorded according to technical scheme 12, in rotatably thrust bearing in bowl-shape bearing In the shaft end 30d of the rotary shaft body 30 of part 40 with the bottom surface of bowl-shape parts of bearings 40 to the axial end 30f to connect, Axial end 30f periphery edge 30fe inner side, oil groove 30v is formed along periphery edge 30fe, therefore, oil groove 30v leaves Periphery edge 30fe is individually formed in axial end 30f, and therefore, oil groove 30v is easy to accumulate oil, the axial end 30f of rotary shaft body 30 In the state of surface is maintained at by oil groove 30v oil appropriateness, connects with the bottom surface of bowl-shape parts of bearings 40, pushed away Power supports.

Therefore, in the rotating against of the relatively bowl-shape parts of bearings 40 of rotary shaft body 30, by moderately being protected in axial end 30f Oil is held, appropriate rotational resistance can be maintained, carries out thrust bearing, can more reliably cause feed screw mechanism action, meanwhile, Also the abrasion of thrust bearing can be suppressed.

The feed screw formula tensioning apparatus recorded according to technical scheme 13, above-mentioned oil groove 30v is by a plurality of what is circumferentially split Arc-shaped oil groove is formed, and therefore, can be balanced in the axial end 30f of rotary shaft body 30 after whole surface and be disperseed well and protect Oil is held, in rotary shaft body 30 is relative to the rotating against of bowl-shape parts of bearings 40, can effectively maintain appropriate rotational resistance, Carry out thrust bearing.

The feed screw formula tensioning apparatus recorded according to technical scheme 14, even in the shaft end 30d of rotary shaft body 30, Be cut into the slit locking hole 30e occasions of locking one end of torsion spring 45 from axial end 30f along axis center, arc-shaped oil groove 30v from Slotted locking hole 30e is formed, and therefore, arc-shaped oil groove 30v leaves slit locking hole 30e and is individually formed in axial end 30f, because This, arc-shaped oil groove 30v is easy to long-pending oil, and the axial end 30f of rotary shaft body 30 is moderately keeping oil by oil groove 30v on surface Under state, connect with the bottom surface of bowl-shape parts of bearings 40, carry out thrust bearing.

Therefore, in rotary shaft body 30 is relative to the rotating against of bowl-shape parts of bearings 40, shaft end is maintained at by appropriateness Face 30f oil, the rotational resistance of appropriateness can be maintained, carry out thrust bearing, can more reliably cause feed screw mechanism action, together When, it can also suppress the abrasion of thrust bearing.

Brief description of the drawings

Fig. 1 is the valve for the internal combustion engine for representing the feed screw formula tensioning apparatus that the embodiment for being applicable the present invention is related to The figure of drive system.

Fig. 2 is to represent that this feed screw formula tensioning apparatus is arranged on the sectional view of the state of drive chain case.

Fig. 3 is the rearview of this feed screw formula tensioning apparatus.

Fig. 4 is the front view of this feed screw formula tensioning apparatus.

Fig. 5 is the decomposition section of this feed screw formula tensioning apparatus.

Fig. 6 is Fig. 5 VI-VI direction views.

Fig. 7 is Fig. 6 VII-VII line sectional views.

Fig. 8 is the front view of cylinder.

Fig. 9 is the front view of guide member.

Figure 10 is the amplification stereogram for the rotary shaft body that the 1st variation is related to.

Figure 11 is the amplification stereogram for the rotary shaft body that the 2nd variation is related to.

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

Figure 13 is the amplification stereogram for the rotary shaft body that the 3rd variation is related to.

Symbolic significance is as follows in figure：

1- internal combustion engines

2- crankcases

3- cylinder block

3c- drive chain cases

4- cylinder heads

5- cowl hoods

6- bent axles

10- valve mechanisms

11- camshafts

12- camshaft chains (cam chain)

13- guide chain parts

14- tension slides

15- fulcrums

16- camshaft chains room

20- feed screw formula tensioning apparatus

21- stretcher shells

22- bottom walls

22d- bearing recess

23- cylindrical walls

23k- engaging recessed parts

24th, 25,26- oil guide grooves

27- slit grooves

30- rotary shaft bodies

30a- outer screw sections

30b- screw thread base end parts

30c- extensions

30d- branch axle portion (shaft end)

30e- slit locking hole

30f- axial ends

30g- chamfered sections

30v- (arc-shaped) oil groove

31- pushes body

32- cylinders

33- is covered

34th, 35- guide members

35a- inserts through hole

35k- engagement pawls

The bowl-shape packing rings of 40- (bowl-shape parts of bearings)

41- otch

45- disc springs (torsion spring)

46- back-up rings

47- packing rings

48- cylindrical sleeve parts

50- sealing screws

51-O type circles

60- brakes locking piece

Embodiment

Below, an embodiment of the present invention is illustrated based on Fig. 1 to Fig. 9.

The feed screw formula tensioning apparatus 20 that this embodiment is related to uses as camshaft chain stretcher, camshaft The bent axle 6 for the stroke IC engine 1 of SOHC types 4 that driving-chain 12 erects power from cylinder is transferred to the camshaft 11 of top, above-mentioned When camshaft chain stretcher is normal tension force is given to camshaft chain 12.

The internal combustion engine 1 is equipped in vehicle, and in this manual, all around direction is set to according to the usual benchmark of vehicle, I.e. using carry internal combustion engine 1 vehicle direction of advance as front.

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

On the crankcase 2 of axle branch bent axle 6, overlapping cylinder block 3, cylinder head 4 are combined successively, and gas is coated on cylinder head 4 Cowl hood 5.

The cylinder of cylinder block 3 erects posture in what is somewhat leaned forward.

Cylinder head 4 is arranged at by the valve mechanism 10 of the rotation driving of camshaft 11.

Rotatably it is supported on the shaft on the camshaft 11 of cylinder head 4 and bent axle 6 is abreast disposed in the top of bent axle 6, in song The left end of axle 6 is embedded drive sprocket 6s, in contrast, is embedded in the left end of camshaft 11 by movable sprocket 11s, as endless drive The camshaft chain 12 of band is erected at drive sprocket 6s and by movable sprocket 11s.

Be set up in drive sprocket 6s and by the camshaft chain 12 on movable sprocket 11s it is up and down long extend it is front and rear The front side length part of long part is oriented to by guide chain part 13 that is micro-bend and extending in long way, the rear side of the opposing party length part by bending into The tension slide 14 of arch pushes from rear.

The lower end of tension slide 14 is supported on the shaft on fulcrum 15 near bent axle 6, and the part extended upward is with before and after being set to Swing freely.

Camshaft chain 12 and guide chain part 13, tension slide 14 penetrate the camshaft chain room 16 of cylinder block 3, transmission It is in form the rectangular drum like of the camshaft chain room 16 with case, in the rear wall 3cr of the drive chain case 3c as above-mentioned transmission belt case, This feed screw formula tensioning apparatus 20 is installed.

The stretcher shell 21 of feed screw formula tensioning apparatus 20 forms bottomed cylindrical, bottom by bottom wall 22 and cylindrical wall 23 Wall 22 extends from cylindrical wall 23 to peripheral direction in Flange-shaped Parts, and especially, a pair of symmetric parts further extend, and form the method for rhombus Blue portion 22f, screw mounting hole 22fh, 22fh (reference picture 3, Fig. 4) are formed in the flange portion 22f part that is symmetrically extended.

In the drive chain case 3c of cylinder block 3 rear wall 3cr, formed with the external diameter of the cylindrical wall 23 of stretcher shell 21 substantially Equal circular hole 3ch, in order to which feed screw formula tensioning apparatus 20 is installed on drive chain case 3c, from drive chain case 3c rear wall 3cr The cylindrical wall 23 of stretcher shell 21 is inserted into rear wall 3cr circular hole 3ch by outside, makes flange portion by seal member 71 22f and rear wall 3cr is abutted against, and makes screw 70,70 by screw mounting hole 22fh, and 22fh is screwed in drive chain case 3c rear wall 3cr, peace Put into screw tensioning apparatus 20.

If as shown in figure 1, the central shaft X of the cylindrical wall 23 of the stretcher shell 21 of feed screw formula tensioning apparatus 20 is in It is dry to tilt, but horizontal direction is pointed generally in, it is installed on drive chain case 3c rear wall 3cr.

Drive chain case 3c rear wall 3cr feed screw formula tensioning apparatus 20 is installed on, pushes body 31 from stretcher shell 21 Cylindrical wall 23 protruded forwards on central shaft X, push tension slide 14, give tension force to camshaft chain 12.

The construction of this feed screw formula tensioning apparatus 20 described further below.

As previously noted, stretcher shell 21 is formed by possessing flange portion 22f bottom wall 22 and cylindrical wall 23, in bottom wall 22 Center wear screw 22a, in screw 22a open rearward end edge, along the circumferential direction equally spaced carve and set 6 radiation direction Locking groove 22k, and then, form annular recess 22r (reference picture 3, Fig. 5, Fig. 7) in its periphery.

In annular recess 22r mounting O-shaped rings 51, flanged (FLGD) sealing screw 50 is screwed in screw 22a and is closed (ginseng According to Fig. 2, Fig. 5).

In the screw 22a in the center of bottom wall 22 front opening edge, circular recessed bearing recess 22d is formed.

In this bearing recess 22d, the embedded bowl-shape packing ring 40 as parts of bearings.

Bowl-shape packing ring 40 be with hollow bottom wall, in the bowl-shape thrust bearing part of flattened cylinder shape, external diameter with Bearing recess 22d internal diameter is equal, and axial width is identical with bearing recess 22d depth, the bowl-shape overall embedded bearing of packing ring 40 In recess 22d (reference picture 2, Fig. 5, Fig. 7).

In order to prevent the bearing recess 22d of the stretcher shell 21 of aluminum because directly rotatably thrust bearing is described later Rotary shaft body 30 causes abrasion, and Jie has installation bowl-shape packing ring 40 made of iron.

The circular hole 40a in the bottom wall center of bowl-shape packing ring 40 and the screw 22a in the center of bottom wall 22 of stretcher shell 21 are substantially Same diameter.

The opening end edge portion of bowl-shape packing ring 40 herein, circumferentially form multiple otch 41 (reference picture 5, Fig. 6).

The cylindrical wall 23 of stretcher shell 21 protrudes forwards from bottom wall 22, and the cylindrical wall 23 is with the cardinal extremity from bottom wall 22 Portion to front opening edge, wall thickness is thinning, forms the thin cross sectional shape in front end.

That is, the outer peripheral face of cylindrical wall 23 forms circular conical surface so that from bottom wall 22 it is lateral front opening edge, external diameter become Small, the inner peripheral surface of cylindrical wall 23 forms circular conical surface, from bottom wall 22 it is lateral front opening edge, internal diameter become big.

In the outer peripheral face and inner peripheral surface of the circular conical surface for forming this cylindrical wall 23, circumferentially formed and multiple be pointed generally in central shaft The oil guide groove 24,25 of X axial direction (some inclinations).

Oil guide groove 24,25 a plurality of adjacent assortment, is formed after all-round continuous waveform in the circumference of cylindrical wall 23.

The oil guide groove 25 of the inner peripheral surface of cylindrical wall 23 extends up to the bottom surface (reference picture 5, Fig. 7) of bottom wall 22.

In the inner side of the cylindrical wall 23 of bottom wall 22, the ring-type bottom surface in bearing recess 22d outside, from central shaft X towards putting Penetrate direction and form a plurality of oil guide groove 26 (reference picture 6).

The oil guide groove 26 of this bottom surface connects with the oil guide groove 25 of the inner peripheral surface of cylindrical wall 23, meanwhile, it is also recessed with embedded bearing The otch 41 formed at the portion 22d opening end edge portion of bowl-shape packing ring 40 connects (reference picture 2).

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

In the front opening edge of cylindrical wall 23,4 wide engaging recessed part 23k (reference pictures are circumferentially, equally spaced formed 5, Fig. 6).

Also, in cylindrical wall 23, bearing recess 22d of the slit groove 27 from front opening edge to bottom wall 22 is axially cut, It is respectively formed between adjacent engaging recessed part 23k, 23k (reference picture 5, Fig. 7).

Slit groove 27 is deeply cut into more than the bearing recess 22d of bottom wall 22 bottom surface (reference picture 7).

In the local perforations of the bottom wall 22 along cylindrical wall 23, locking hole 23e is formed.

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

In addition, the outer peripheral face in the front opening end of cylindrical wall 23, the axially front in engaging recessed part 23k bottom surface Set position, it is along the circumferential direction all-round to form circumferential groove 23c.

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

In the inside of the cylindrical wall 23 of such stretcher shell 21, in the central shaft X of cylindrical wall 23, rotary shaft is arranged Body 30 and pushing body 31, above-mentioned one end of rotary shaft body 30 are rotatably supported on the shaft on the axle to be formed in the bottom surface of bottom wall 22 center Concave portion 22d, above-mentioned pushing body 31 screws up with the screw thread of rotary shaft body 30, by rotating against, in the central shaft X of cylindrical wall 23 Upper advance and retreat, camshaft chain 12 is pushed by advancing.

Reference picture 5, rotary shaft body 30 are cylindric, and order is coaxially formed continuously pin thread since tip side (front) Portion 30a, screw thread base end part 30b, extension 30c, branch axle portion 30d.

Outer screw section 30a is formed as most long, and extension 30c forms external diameter some cylindric, branch bigger than outer screw section 30a Axle portion 30d forms the flattened cylindrical shape that external diameter is bigger than extension 30c, axial width is narrow, in the bottom wall 22 than stretcher shell 21 Bearing recess 22d it is small one circle flattened cylindrical shape.

Branch axle portion 30d and extension 30c in rotary shaft body 30, from the circular rear end shaft end for forming branch axle portion 30d Face 30f, until extension 30c, is cut into slit locking hole 30e dearly along the plane comprising central shaft.

As shown in Fig. 2 arranging the disc spring 45 for being wound into scroll around the extension 30c of rotary shaft body 30, prolonging Extending portion 30c slit locking hole 30e, the medial end 45b of locking disc spring 45.

In addition, the outboard end 45a of disc spring 45, as previously noted, engaging in stretcher shell 21 cylindrical wall 23 it is locking Hole 23e (reference picture 2).

Body 31 is pushed to form by cylinder 32 and with the lid 33 of its front end riveting.

Reference picture 5 and Fig. 8, the inner peripheral surface of cylinder 32 carve the negative thread for setting and being screwed up with the outer screw section 30a of rotary shaft body 30 The corresponding face truncation of periphery is formed a pair of parallel tabular surface 32b, 32b, its section is in by 32a, the outer peripheral face of cylinder 32 Deform long round shape.

In addition, the rear end of cylinder 32 retains the periphery 32c of non-truncation.

The limitation rotation of guide member 35, supports the cylinder 32 to move axially freely.

Reference picture 5 and Fig. 9, guide member 35 is disc-shaped, and center has to be become with the cross sectional shape identical of above-mentioned cylinder 32 The insertion through hole 35a of the long round shape of shape, in peripheral part, engagement pawl 35k is protruded respectively in cross radiation direction.

4 engagement pawl 35k of guide member 35 are with forming in the front opening edge of the cylindrical wall 23 of stretcher shell 21 4 engaging recessed part 23k engagings, by the way that the back-up ring 46 of C-shaped to be embedded in the circumferential groove 23c of cylindrical wall 23, limit guide member 35 Movement in the axial direction, prevent come off (reference picture 2).

As shown in Fig. 2 in the case where the screw thread of cylinder 32 of rotary shaft body 30 and pushing body 31 screws up state, the rotary shaft body of a side 30 rear end is rotatably supported on the shaft on the bearing recess 22d of the bottom wall 22 of stretcher shell 21 by bowl-shape packing ring 40, another The cylinder 32 of side penetrates the insertion through hole 35a of guide member 35, and limited swivel, axial movement support freely.

In addition, hollow discoideus packing ring 47 is in the screw thread base end part 30b of rotary shaft body 30 position, from front and extension Portion 30c side connects, and being situated between this packing ring 47 and guide member 35 has installation cylindrical sleeve part 48, positioning guide members 35 Axial location.

Hereinafter, the assembling sequence of the feed screw formula tensioning apparatus 20 so constructed based on Fig. 5 simple declarations.

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

The disc spring 45 of scroll causes outermost layer portion to connect with the inner peripheral surface close to the bottom surface of cylindrical wall 23 so that from outermost layer Locking hole 23es of the outboard end 45a that portion extends laterally engaging in cylindrical wall 23.

In this case, the overwhelming majority of disc spring 45 from inside winding in outermost layer portion, central portion be it is hollow, it is hollow herein Portion, medial end 45b extend to center.

Rotary shaft body 30 is inserted in cylindrical wall 23, the extension 30c of rotary shaft body 30 and branch axle portion 30d are inserted into disk The hollow bulb of spring 45, now, the medial end 45b of disc spring 45 is inserted to the slit card to be formed in extension 30c and branch axle portion 30d It is locking to determine hole 30e progress, and then, by the branch axle portion 30d insertion bearing recess 22d axle branch of bowl-shape packing ring 40.

Herein so that the rotary shaft body 30 for being supported on the shaft on bowl-shape packing ring 40 rotates, and winds disc spring 45, when fully winding, from outer Side will be made up of one leg and two-arm and insert bottom wall 22 in the braking locking piece 60 (being represented in figure 3 with double dot dash line) of T-shaped Screw 22a, by the front end of one leg engaging in slit locking hole 30e, while by two-arm engaging in being formed in the outer of screw 22a Locking groove 22k, the 22k in symmetric position of side opening edge, it is set to the state for forbidding rotary shaft body 30 to rotate by disc spring 45.

In this case, packing ring 47 and cylindrical sleeve part 48 is penetrated rotary shaft body 30, insert in cylindrical wall 23, then, The cylinder 32 of body 31 is will push against to screw up with the outer screw section 30a screw threads of rotary shaft body 30.

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

Then so that cylinder 32 penetrates the insertion through hole 35a of the long round shape of deformation of guide member 35 so that 4 engagement pawls 35k is sticked in the 4 engaging recessed part 23k to be formed in the front opening edge of the cylindrical wall 23 of stretcher shell 21, by C-shaped back-up ring The circumferential groove 23c of 46 insertion cylindrical walls 23, limits the axial movement of guide member 35, is installed.

Lid 33 is riveted to the front end for being incorporated in cylinder 32, makes the integration of pushing body 31.

The rear end branch axle portion 30d of rotary shaft body 30 is rotatably supported on the shaft on the bearing recess 22d of bottom wall 22 bowl-shape pad Circle 40, push body 31 and protruded forwards from the insertion through hole 35a of guide member 35, axially movably supported in guide member 35。

Feed screw formula tensioning apparatus 20 as assembled above is in the state of braking locking piece 60 is provided with, in cylinder block 3 Drive chain case 3c rear wall 3cr, cylindrical wall 23 is inserted into circular hole 3ch, flange portion 22f and rear wall 3cr are made by seal member 71 Abut against so that screw 70,70 screws up the installation (reference on drive chain case 3c rear wall 3cr by screw mounting hole 22fh, 22fh Fig. 1, Fig. 2).

Push body 31 rotate against axis body 30 the screw thread amount of screwing up be set as it is optimal, push body 31 lid 33 be in positioned at The state that the tension slide 14 of initial, set position connects.

If here, unloading braking locking piece 60, the spring force of the disc spring 45 wound just applies to rotary shaft body 30, caused Rotary shaft body 30 rotates, and the pushing body 31 screwed up with the screw thread of rotary shaft body 30 advances, and pushing camshaft by tension slide 14 passes Dynamic chain 12, tension force is given to camshaft chain 12.

The screw 22a of the bottom wall 22 of braking locking piece 60 is unloaded beforehand through O-ring 51 by flanged (FLGD) sealing screw 50 Screw thread screws up closing.

The feed screw formula tensioning apparatus 20 so installed, push body 31 and the spiral shell of rotary shaft body 30 energized by disc spring 45 Line screws up, and therefore, will not retreat, if relaxation is produced in camshaft chain 12, because the spring force of disc spring 45 makes rotary shaft body 30 rotations, make pushing body 31 advance, tension force are given to camshaft chain 12 when normal.

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

The oil to be dispersed by the rotation of camshaft chain 12, it is attached to cylinder head 4 and the drive chain case 3c of cylinder block 3 Internal face, as shown in Fig. 2 the oil that the inner face for being attached to drive chain case 3c rear wall 3cr flows down, runs down into from rear wall 3cr to inner side The upside outer peripheral face of the cylindrical wall 23 of the stretcher shell 21 of prominent feed screw formula tensioning apparatus 20.

The outer peripheral face of cylindrical wall 23 forms circular conical surface, its from bottom wall 22 it is lateral front opening edge, external diameter diminish, upside It is partially toward front end and becomes low land and tilts, meanwhile, oil guide groove 24 is formed continuous in a plurality of adjacent assortment of circumference of cylindrical wall 23 Waveform, therefore, the oil for running underneath to the upside outer peripheral face of the cylindrical wall 23 of stretcher shell 21 guide through oil guide groove 24, around entering cylinder The engaging recessed part 23k of wall 23 or front opening edge, into the inner peripheral surface side of cylindrical wall 23.

In addition, as shown in Fig. 2 guide member 35 is positioned by cylindrical sleeve part 48, in engaging recessed part 23k bottom surface and draw Leading between the engagement pawl 35k of part 35 has space, inner peripheral surface side of the oil around to cylindrical wall 23.

The inner peripheral surface of cylindrical wall 23 forms circular conical surface so that become big from bottom wall side 22 towards front opening edge internal diameter, on Side, which is partially toward the side of bottom wall 22 and becomes low land, to be tilted, meanwhile, oil guide groove 25 is formed straight in a plurality of adjacent assortment of circumference of cylindrical wall 23 To the continuous waveform of the bottom surface of bottom wall 22, therefore, promote the oil into the inner peripheral surface side of cylindrical wall 23 towards bottom wall 22, along oil guide groove 25 flow to bottom wall 22, the oil guide groove 26 from axis center sensing radiation direction that will be formed in oil guiding to the bottom surface of bottom wall 22, concentrate In the bearing recess 22d in center bowl-shape packing ring 40.

In the opening end edge portion of bowl-shape packing ring 40, multiple otch 41 are circumferentially being formed, therefore, are concentrating on bowl-shape packing ring 40 Oil can swimmingly be supplied to the bearing portion of the rotary shaft body 30 of the bowl-shape inner side of packing ring 40 by oil by otch 41.

Against the bearing of the rotary shaft body 30 of bowl-shape packing ring 40, radial load and the side of axial load two are supported, especially, by The axial axial load effect of the rotary shaft body 30 of the tension force of camshaft chain 12 is very big, therefore, to rotary shaft body 30 Axial end 30f and bowl-shape packing ring 40 the fuel feeding at thrust bearing position that connects of bottom surface it is critically important.

The oil guide groove 26 of the bottom surface of bottom wall 22 is formed as deeper than the oil guide groove 24,25 of cylindrical wall 23, accordingly, it is capable to cause oil in advance The bottom surface of bottom wall 22 is lodged in, therefore, oil can be stably supplied to the thrust bearing position of rotary shaft body 30.

So, this feed screw formula tensioning apparatus 20 will attach to the oil that drive chain case 3c internal face flows down and efficiently import In the cylindrical wall 23 of stretcher shell 21, the bearing portion of rotary shaft body 30 can be sufficiently fed, prevents from wearing away.

It is not required to form oil duct, simple structure in the wall of stretcher shell 21, transmission belt case 3c sides are also not required to design oil supply gallery, So when being used in internal combustion engine also limitation will not be produced because type of internal combustion engine is different, very high versatility can be maintained, can be dropped Low cost.

Reference picture 6, the feed screw formula tensioning apparatus 20 of this embodiment are installed on transmission belt case 3c so that in stretcher 1 engaging recessed part 23k turns on just in 4 engaging recessed part 23k that the front opening edge of the cylindrical wall 23 of shell 21 is formed Side, therefore, runs underneath to the oil of the upside outer peripheral face of the cylindrical wall 23 of stretcher shell 21, from surface, engaging recessed part 23k week Oil into width is induced to flow into oil guide groove 24, flows through engaging recessed part 23k bottom surface, around the inner peripheral surface side for entering cylindrical wall 23, Oil beyond engaging recessed part 23k circumferential width left-right parts is induced to flow into oil guide groove 24, and the front end for flowing through cylindrical wall 23 is opened Mouth end face, around the inner peripheral surface side for entering cylindrical wall 23.

Alternatively, it is also possible to be formed in advance in engaging recessed part 23k bottom surface and the front opening end face of cylindrical wall 23 from axle The heart points to the groove of radiation direction, and by the groove, oil can be more swimmingly around the inner peripheral surface side for entering cylindrical wall 23.

In cylindrical wall 23, there is slit groove 27 between engaging recessed part 23k, 23k, therefore, in the first half of cylindrical wall 23, As the engaging recessed part 23k of the surface left and right sides, from front opening edge to bottom wall untill 22 bearing recess 22d, deposit In the slit groove 27 (reference picture 6) cut vertically.

It is as described above, should be left around the oil for being induced to flow into oil guide groove 24 for entering engaging recessed part 23k or front opening edge Right spilling, or run underneath to the oil of the position of slit groove 27, into slit groove 27, the inner circumferential of cylindrical wall 23 is flowed out to from slit groove 27 Face, oil can be directly supplied to the bearing recess 22d of incision slit groove 27, by increasing capacitance it is possible to increase to the bowl of supporting rotating shaft body 30 The fuel delivery of the bearing portion of shape packing ring 40.

All-round formation of the waveform formed by oil guide groove 24,25 after cylindrical wall 23, therefore, makes when by stretcher shell 21 The central shaft X of cylindrical wall 23 when being mounted substantially horizontally on transmission belt case 3c, can regardless of cylindrical wall 23 setting angle such as What, the total outer peripheral face and inner peripheral surface that cause oil guide groove 24,25 to be located at upside, therefore, the installation free degree of stretcher shell 21 are high, Versatility is improved.

Stretcher shell 21 by be divided into the central shaft X of cylindrical wall 23 axial direction two mould molding, pass through the mould It can simultaneously shape and be pointed generally in axial oil guide groove 24,25, meanwhile, because forming the outer peripheral face and inner peripheral surface of circular conical surface, in axial direction It can make it that forming the thin cylindrical wall 23 of head is stripped, and is easily formed.

The present invention is not limited to embodiment described herein, for example, oil guide groove 24,25 also can be by single groove structure Into.

Secondly, as other embodiments, one end is supported on the shaft on to the bearing recess 22d of embedded stretcher shell 21 bowl The variation of the rotary shaft body 30 of shape packing ring 40, represent, in Figure 10 to Figure 13, to illustrate.

The part phase of other parts and the feed screw formula tensioning apparatus 20 of above-mentioned embodiment in addition to rotary shaft body Together, also shape is identical in addition to axial end for rotary shaft body, therefore, for part/part including rotary shaft body, using same Symbol is illustrated.

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

Branch axle portion 30d as the shaft end of this rotary shaft body 30 inserts bowl-shape packing ring 40, as journal bearing, makees simultaneously For thrust bearing.

Axial axial load by the rotary shaft body 30 of the tension force of camshaft chain 12 is big, therefore, this bowl-shape pad Circle 40 is especially big as the effect of thrust bearing.

Bottom surface with the branch axle portion 30d of rotary shaft body 30 bowl-shape packing ring 40 to the axial end 30f of contact to forming circle Plane, to peripheral part chamfering, form the chamfered section 30g of taper.

Rotary shaft body 30 shaft end 30d, the medial end 45b of locking disc spring 45 slit locking hole 30e from shaft end Face 30f is cut into along axis center, and thus, axial end 30f circular flat is divided into 2 semicircles by slit locking hole 30e.

The branch axle portion 30d of this rotary shaft body 30 axial end 30f processing is formed as JISB601：It is maximum high as defined in 2001 It is more than 7, less than 26 such surface roughnesses to spend roughness Rz.

As previously noted, it is attached to the oily cylindrical wall from stretcher shell 21 that drive chain case 3c rear wall 3cr inner face flows down 23 outer peripheral face concentrates on the bearing recess 22d in center bowl-shape packing ring 40 around inner peripheral surface is entered, and penetrates into the bowl-shape inner side of packing ring 40 Rotary shaft body 30 bearing portion, lubricate bearing portion.

Concentrate on the journal bearing portion of the oil branch axle portion 30d of infiltration rotary shaft body 30 periphery first of bowl-shape packing ring 40 Position, then reach the thrust bearing position that the axial end 30f of rotary shaft body 30 connects with the bowl-shape bottom surface of packing ring 40.

The oily maximum height roughness Rz that is fully held in for importeding into thrust bearing position is more than 7, less than 26 such Surface roughness axial end 30f the surface roughness convex-concave surface.

So, in the state of the axial end 30f of rotary shaft body 30 fully keeps oil, the bottom surface phase with bowl-shape packing ring 40 Connect, carry out thrust bearing, it is therefore, thick for more than 7, less than 26 such surfaces in axial end 30f maximum height roughness Rz The convex-concave surface of rugosity can fully keep oil, because of the oily lubrication, suppress relative because of the relatively bowl-shape packing ring 40 of rotary shaft body 30 Rotational resistance caused by rotation increases due to the axial end 30f of rotary shaft body 30 surface roughness, maintains appropriate rotation Turn resistance, carry out thrust bearing, can more reliably cause feed screw mechanism action.

In addition, the abrasion of thrust bearing can also be suppressed by the oil fully kept.

The axial end 30f of rotary shaft body 30 maximum height roughness Rz occasions smaller than 7, the relatively bowl-shape pad of rotary shaft body 30 Resistance in 40 rotate against of circle natively very little, it is difficult to appropriate rotational resistance is obtained by oil, meanwhile, oily retentivity Also can reduce.

Also, maximum height roughness Rz occasions bigger than 26, in the rotating against of the relatively bowl-shape packing ring 40 of rotary shaft body 30 Resistance is natively excessive, keeps oil to be also difficult to obtain appropriate rotational resistance even if abundant.

Secondly, on the 2nd variation of rotary shaft body 30, represent, in Figure 11 and Figure 12, to illustrate.

The bottom surface of bowl-shape packing ring 40 with the branch axle portion 30d of the rotary shaft body 30 with the 1st to the axial end 30f to connect, becoming Shape example is identical, and its circular flat is divided into 2 semicircles by slit locking hole 30e, carries out chamfering to peripheral part, forms taper Chamfered section 30g.

In the branch axle portion 30d of the rotary shaft body 30 axial end 30f, in axial end 30f periphery edge 30fe Side, oil groove 30v is formed along periphery edge 30fe.

Axial end 30f oil groove 30v is split by slit locking hole 30e, meanwhile, further circumferentially split, as a result split For 4, the oil groove 30v of segmentation forms mutually same arc-shaped, as the arc-shaped oil groove 30v of 4 same shapes, circumference with Substantially formed at equal intervals.

In the axial end 30f of rotary shaft body 30 periphery edge 30fe inner side, circumferentially edge 30fe forms each circular arc Shape oil groove 30v, and the end of arc-shaped oil groove 30v slit locking hole 30e sides is left slit locking hole 30e and formed, therefore, circle Arcuation oil groove 30v and chamfered section 30g departs from, and also departs from slit locking hole 30e, is individually formed in axial end 30f.

Therefore, it is easy to accumulate oil in each arc-shaped oil groove 30v.

In the axial end 30f of rotary shaft body 30, the arc-shaped oil groove that this is easy to accumulate oil in circumferential equably arranging 4 30v, therefore, in the axial end 30f entire surfaces of rotary shaft body 30, dispersed oil, holding oil well can be balanced.

Therefore, the axial end 30f of rotary shaft body 30 is moderately protected well by 4 arc-shaped oil groove 30v in surface balance In the state of holding oil, contacted with the bottom surface of bowl-shape packing ring 40, form thrust bearing.

That is, it is good by being balanced in axial end 30f in rotary shaft body 30 is relative to the rotating against of bowl-shape packing ring 40 Ground moderately keeps oil, can maintain appropriate rotational resistance, forms thrust bearing, more reliably feed screw mechanism can be moved Make, it is also possible to suppress the abrasion of thrust bearing.

So, the rotary shaft body 30 of the 2nd variation forms 4 articles of arc-shaped oil groove 30v in axial end 30f, but the present invention is simultaneously Be not limited to this, for example, the 3rd variation is such as shown in fig. 13 that, by the slit locking hole 30e of rotary shaft body 30 split The arc-shaped oil groove 30v that the axial end 30f of one side is formed be so that the segmentation in the 2nd variation arc-shaped oil groove 30v connections, It is set to an arc-shaped oil groove 30v.

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

Further, the axial end 30f of rotary shaft body 30 is processed into required surface roughness, it is also possible to add Work forms oil groove for the axial end 30f of required surface roughness.

It is above-mentioned above, feed screw formula tensioning apparatus of the present invention is illustrated, but the form of the present invention not only limits In above-mentioned embodiment, include in idea of the invention scope and implemented with variform.

Claims (14)

1. a kind of feed screw formula tensioning apparatus, including：

Stretcher shell (21), bottomed cylindrical, the center of above-mentioned cylindrical wall (23) are formed by bottom wall (22) and cylindrical wall (23) Axle (X) is pointed generally in level, installed in transmission belt case (3c)；

Rotary shaft body (30) so that the bearing that one end is rotatably supported on the shaft on the bottom surface center for being formed at above-mentioned bottom wall (22) is recessed Portion (22d)；

Body (31) is pushed, is screwed up with above-mentioned rotary shaft body (30) screw thread, by the guiding for being arranged at above-mentioned cylindrical wall (23) opening portion Part (35) limitation rotation, meanwhile, axle branch is that movement freely, passes through above-mentioned rotation on the central shaft (X) of above-mentioned cylindrical wall (23) The rotation of 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), energized towards a direction of rotation；

The annular driving band (12) of passing power is pushed by the advance of above-mentioned pushing body (31), to above-mentioned annular driving band (12) Tension force is given when often；

In above-mentioned feed screw formula tensioning apparatus, it is characterised in that：

It is installed among the above-mentioned cylindrical wall (23) of above-mentioned stretcher shell (21) of above-mentioned transmission belt case (3c), at least upper half The outer peripheral face and inner peripheral surface in portion, formation are pointed generally in axial oil guide groove (24,25).

2. the feed screw formula tensioning apparatus according to described in claim 1, it is characterised in that：

Circumference of the above-mentioned oil guide groove (24,25) in above-mentioned cylindrical wall (23), it is a plurality of adjacent with being classified as, form continuous waveform.

3. the feed screw formula tensioning apparatus according to described in claim 2, it is characterised in that：

The waveform that above-mentioned oil guide groove (24,25) is formed, the all-round formation after cylindrical wall (23).

4. the feed screw formula tensioning apparatus according to described in Claims 2 or 3, it is characterised in that：

The above-mentioned oil guide groove (25) of the inner peripheral surface of above-mentioned cylindrical wall (23), extend up to the bottom surface of above-mentioned bottom wall (22).

5. the feed screw formula tensioning apparatus recorded according to any of claims 1 to 3, it is characterised in that：

In the bottom surface of above-mentioned bottom wall (22), a plurality of groove (26) that radiation direction is pointed to from axis center is formed.

6. the feed screw formula tensioning apparatus recorded according to any of claims 1 to 3, it is characterised in that：

It is recessed at least first half, the above-mentioned bearing from front opening edge to above-mentioned bottom wall (22) among above-mentioned cylindrical wall (23) Portion (22d), formed towards the slit groove (27) axially cut.

7. the feed screw formula tensioning apparatus recorded according to any of claims 1 to 3, it is characterised in that：

The outer peripheral face of above-mentioned cylindrical wall (23) forms circular conical surface so that from above-mentioned bottom wall (22) it is lateral front opening edge, outside Footpath diminishes；

The inner peripheral surface of above-mentioned cylindrical wall (23) forms circular conical surface so that from above-mentioned bottom wall (22) it is lateral front opening edge, it is interior Footpath becomes big.

8. the feed screw formula tensioning apparatus according to described in claim 7, it is characterised in that：

Above-mentioned stretcher shell (21) by be divided into the axial direction of the central shaft (X) of above-mentioned cylindrical wall (23) two mould molding.

9. the feed screw formula tensioning apparatus according to described in claim 1, it is characterised in that：

Pass through the bowl-shape parts of bearings (40) for the above-mentioned bearing recess (22d) for being fitted to above-mentioned bottom wall (22), above-mentioned rotary shaft body (30) one end rotates freely the earth's axis and propped up；

In the opening end edge portion of above-mentioned bowl-shape parts of bearings (40), multiple otch (41) are circumferentially being formed.

10. the feed screw formula tensioning apparatus according to described in claim 9, it is characterised in that：

Rotatably thrust bearing is in the shaft end (30d) of the above-mentioned rotary shaft body (30) of above-mentioned bowl-shape parts of bearings (40) With the bottom surface of above-mentioned bowl-shape parts of bearings (40) to the axial end (30f) to connect, the surface required for processing is formed as is thick Rugosity.

11. the feed screw formula tensioning apparatus according to described in claim 10, it is characterised in that：

Above-mentioned axial end (30f) processing of above-mentioned rotary shaft body (30) is formed as maximum height roughness Rz as more than 7, less than 26 Such surface roughness.

12. the feed screw formula tensioning apparatus according to described in claim 9 or 10, it is characterised in that：

Rotatably thrust bearing the above-mentioned rotary shaft body (30) of above-mentioned bowl-shape parts of bearings (40) shaft end (30d) In with the bottom surface of above-mentioned bowl-shape parts of bearings (40) to the axial end (30f) to connect, in the outer peripheral edge of the axial end (30f) The inner side in portion (30fe), oil groove (30v) is formed along the periphery edge (30fe).

13. the feed screw formula tensioning apparatus according to described in claim 12, it is characterised in that：

Above-mentioned oil groove (30v) in a plurality of arc-shaped oil groove (30v) circumferentially split by forming.

14. the feed screw formula tensioning apparatus according to described in claim 13, it is characterised in that：

Shaft end (30d) in above-mentioned rotary shaft body (30), is cut into locking above-mentioned from above-mentioned axial end (30f) along axis center The slit locking hole (30e) of torsion spring (45) one end；

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