阅读说明：本技术 无级变速器 (Continuously variable transmission ) 是由 小林和好 有松正夫 古屋雅之 山本健一 藤井省吾 田村将和 沼田和也 汤川洋久 于 2018-12-06 设计创作，主要内容包括：本发明的无级变速器(1)具备：在一对带轮(5、6)上卷挂有带(V)的变速机构(4)、以及形成用于变速机构(4)的收纳室(80)的壳体(8)。带轮(5、6)具有：固定带轮(51、61)以及可动带轮(55、65)。带(V)具有：层叠并配置成环状的元件(41)、以及将层叠的元件(41)捆束的环(45)。在壳体(8)的周壁部(82),设置有可观察元件(41)的侧面(420、420)的观察孔(87a)。(A continuously variable transmission (1) is provided with: a transmission mechanism (4) having a belt (V) wound around a pair of pulleys (5, 6), and a case (8) forming a housing chamber (80) for the transmission mechanism (4). The pulleys (5, 6) have: fixed pulleys (51, 61) and movable pulleys (55, 65). The belt (V) has: the device comprises elements (41) which are stacked and arranged in a ring shape, and rings (45) which bind the stacked elements (41). An observation hole (87a) through which the side surfaces (420 ) of the element (41) can be observed is provided in the peripheral wall (82) of the housing (8).)

1. A belt type continuously variable transmission is provided with:

a speed change mechanism configured by winding a belt around a pair of pulleys;

a transmission case having a housing chamber of the transmission mechanism,

a desired transmission gear ratio is realized by changing the belt winding radius of each of the pair of pulleys,

the housing chamber has a peripheral wall portion surrounding an outer periphery of the transmission mechanism,

the pair of pulleys are provided inside the peripheral wall portion so as to be rotatable about a pair of rotation shafts set in parallel with each other at intervals,

the pulley has: a fixed pulley and a movable pulley displaceable in the rotation axis direction, and configured to change a winding radius of the belt of the pulley by displacement of the movable pulley in the rotation axis direction,

the belt has: elements stacked and arranged in a ring shape, and rings binding the stacked elements,

the element has side surfaces gripped by the fixed pulley and the movable pulley on both sides in the width direction,

the peripheral wall portion is provided with an observation hole through which the side surface can be observed.

2. The belt type continuously variable transmission according to claim 1,

the side surfaces of the element are regions gripped by the fixed pulley and the movable pulley,

the side surface is formed with ridges that contact the fixed pulley and the movable pulley via an oil film, and grooves that discharge the lubricating oil in the direction in which the elements are stacked, the ridges being alternately arranged in the thickness direction of the belt.

3. The belt type continuously variable transmission according to claim 2,

a winding position of the belt with respect to one of the pair of pulleys and a winding position with respect to the other pulley are displaced in the direction of the rotation shaft in accordance with the transmission gear ratio,

in the peripheral wall portion, the observation hole is provided at a position where a region where displacement in the rotation axis direction of the belt is minimum can be observed.

4. The belt-type continuously variable transmission according to claim 3,

the region of the belt where the displacement in the rotation axis direction is smallest is located in a region of the belt that is not wound around the pulley.

5. The belt-type continuously variable transmission according to claim 3,

the outer periphery of the region of the belt where the displacement in the rotation axis direction is smallest is located on an extension line of the observation hole,

the observation hole is formed so that the distal end side of the inspection tool inserted from the observation hole can be disposed to the depth of one side and the other side in the width direction of the belt.

6. The belt type continuously variable transmission according to claim 5,

a positioning groove of the inspection tool is provided in the observation hole at least at an end portion opened to an inner side of the transmission case,

the positioning grooves are provided in a pair in a symmetrical positional relationship on a diameter line in the width direction of the belt as viewed from the penetrating direction of the observation hole.

7. The belt type continuously variable transmission according to any one of claims 1 to 6,

in the transmission case, the observation hole is opened at a position above an oil level of the lubricating oil in the transmission case in a vertical line direction with reference to an installation state of the continuously variable transmission.

Technical Field

The present invention relates to a belt type continuously variable transmission.

Background

The speed change mechanism unit (speed change mechanism) of the belt type continuously variable transmission includes: a pair of pulleys (a primary pulley, a secondary pulley), and a belt wound around the pair of pulleys.

Patent documents 1 and 2 disclose belts for continuously variable transmissions, in which plate-shaped elements having slit portions on both sides are stacked and arranged in a ring shape, and the elements are bundled by inserting the rings of the slit portions.

The element has side surfaces that contact the sheave surfaces of the pulleys on both sides in the width direction.

In the transmission mechanism portion, a rotational driving force (torque) is transmitted between the pair of pulleys via a belt wound around the pair of pulleys.

Among the respective elements, a side surface (a flat surface) in contact with a pulley surface of the pulley participates in transmission of the rotational driving force.

Patent document 1 discloses that ridges that contact the sheave surface via an oil film and grooves that discharge lubricating oil in the circumferential direction of the pulley are formed on the side surfaces of the elements, alternately arranged in the radial direction of the pulley.

An oil film (reaction film) formed of a lubricating oil is formed at the contact interface between the side surface and the sheave surface.

The groove portion of the side surface has an oil groove depth necessary for promoting the generation of the reaction film so that no metal contact is generated between the pulley surface and the side surface of the belt side.

The side surface ridge portion has an initial wear height at which a reaction film formed between the pulley surface and the belt is not worn.

Some slip occurs between the belt and the pulleys during torque transmission between the pair of pulleys, and the slip causes the belt and the pulleys to generate heat.

Here, if the nipping pressure of the belt with respect to the pair of pulleys is increased to suppress the slip, the contact surface pressure between the side surface of the element and the pulley surface increases, and heat generation due to friction also increases.

When heat generation by friction becomes large, abnormal abrasion and sintering are likely to occur on the side surfaces of the element.

This is because, since the element and the pulley are made of the same metal, if heat generation becomes large, coagulation and damage are easily generated.

Therefore, it is necessary to periodically check for damage on the side of the tape.

In the case of a conventional continuously variable transmission, an oil pan at the lower part of a transmission case is removed, and an inspection tool is inserted from an opening on the oil pan side of the transmission case to confirm that there is no damage.

However, if the oil pan is removed every time of inspection, the lubricating oil in the transmission case also needs to be discharged temporarily, which makes the inspection work troublesome.

Thus, it is required to confirm the presence or absence of damage more easily.

Disclosure of Invention

The belt type continuously variable transmission of the present invention comprises: a speed change mechanism configured by winding a belt around a pair of pulleys; a transmission case having a housing chamber of the transmission mechanism, the housing chamber having a peripheral wall portion surrounding an outer periphery of the transmission mechanism, and a pair of pulleys rotatably provided inside the peripheral wall portion around a pair of rotation shafts set in parallel with each other at intervals, the pulleys having: a fixed pulley and a movable pulley that is displaceable in the rotation axis direction, and is configured to change a winding radius of the belt of the pulley by displacement of the movable pulley in the rotation axis direction, the belt including: and a ring for binding the laminated elements, wherein the elements have side surfaces gripped by the fixed pulley and the movable pulley on both sides in the width direction, and the peripheral wall portion is provided with an observation hole through which the side surfaces can be observed.

According to the present invention, it is possible to easily confirm whether or not the side surface of the element is damaged.

Drawings

Fig. 1 is a diagram illustrating a continuously variable transmission.

Fig. 2 is a diagram illustrating a belt of the continuously variable transmission.

Fig. 3 is a diagram illustrating a casing of the continuously variable transmission.

Fig. 4 is a view illustrating a viewing hole provided in the housing.

Fig. 5 is a view illustrating a viewing hole provided in the housing.

Fig. 6 is a view explaining a positional relationship between the observation hole and the belt.

Detailed Description

Hereinafter, embodiments of the present invention will be described.

As shown in fig. 1, in a belt type continuously variable transmission 1, a rotational driving force of an engine (not shown) is input to a transmission mechanism 4 via a torque converter TC and a forward/reverse switching mechanism 3.

The transmission mechanism 4 includes a pair of pulleys (a primary pulley 5 and a secondary pulley 6), and a belt V wound around the pair of pulleys.

The primary pulley 5 and the secondary pulley 6 are provided rotatably about rotation axes X1, X2 that are parallel to each other.

The primary pulley 5 has: a fixed pulley 51, and a movable pulley 55 displaceable in the direction of the rotation axis X1.

The fixed pulley 51 and the movable pulley 55 have sheave portions 52 and 56 extending in the radial direction of the rotation axis X1, and the facing surfaces between these sheave portions 52 and 56 form sheave surfaces 52a and 56a inclined with respect to the rotation axis X1.

Between these pulley surfaces 52a, 56a, a V-shaped groove for winding the belt V is formed in the primary pulley 5.

In the primary pulley 5, the groove width of the V-shaped groove is changed by displacement of the movable pulley 55 in the direction of the rotation axis X1, thereby changing the winding radius of the belt V in the primary pulley 5.

The secondary pulley 6 also has: a fixed pulley 61, and a movable pulley 65 displaceable in the direction of the rotation axis X2.

The fixed pulley 61 and the movable pulley 65 have sheave portions 62 and 66 extending in the radial direction of the rotation axis X2, and the facing surfaces between these sheave portions 62 and 66 form sheave surfaces 62a and 66a inclined with respect to the rotation axis X2.

In the secondary pulley 6, a V-shaped groove for winding the hanging belt V is formed between these pulley surfaces 62a, 66 a.

In the secondary pulley 6, the groove width of the V-shaped groove is changed by displacement of the movable pulley 65 in the direction of the rotation axis X2, thereby changing the winding radius of the belt V of the secondary pulley 6.

Fig. 2 is a diagram illustrating the structure of the belt V. Fig. 2 (a) is a diagram illustrating the element 41 and the ring 45 constituting the belt V. Fig. 2(b) is a plan view of the element 41, and fig. 2 (c) is a side view of the element 41.

As shown in fig. 2 (a), the belt V has: a plurality of elements 41 stacked and arranged in a ring shape, and a ring 45 binding the stacked elements 41.

The ring 45 is formed by stacking a plurality of thin plates 45a made of high-strength steel plates in a layer shape.

As shown in fig. 2(b) and (c), the element 41 includes: a wedge 42, a head 43, and a connecting portion 44 connecting the wedge 42 and the head 43.

In the element 41, the upper surface of the wedge portion 42 on the head portion 43 side becomes a saddle surface 42a on which the ring 45 slides, and the ring 45 is inserted between the saddle surface 42a and the head portion 43 on both sides of the connecting portion 44.

In the belt V, the element 41 is constrained by a pair of rings 45, 45 located on either side of the connection 44.

Both edges in the width direction of the wedge 42 are side surfaces 420, 420 inclined at a predetermined angle with respect to the center line Lm of the element 41.

The wedge 42 is formed in a shape in which the width in the direction perpendicular to the center line Lm is narrowed as the side surfaces 420 and 420 are separated from the head 43.

In the region where the belt V is wound around the primary pulley 5, the side surfaces 420 and 420 of the element 41 are gripped by the sheave surface 52a of the fixed sheave 51 and the sheave surface 56a of the movable sheave 55 (see the imaginary line in fig. 2 b).

Similarly, in the region where the belt V is wound around the secondary pulley 6, the side surfaces 420 and 420 of the element 41 are gripped by the sheave surface 62a of the fixed sheave 61 and the sheave surface 66a of the movable sheave 65.

The side surfaces 420 and 420 have a plurality of peak portions 420a and groove portions 420b alternately arranged in the vertical direction along the center line Lm.

As shown in fig. 2 (c), the ridge portion 420a and the groove portion 420b extend in the longitudinal direction of the belt V in a side view and are arranged in parallel to each other.

In the transmission mechanism 4, when torque is transmitted via the belt V, gripping forces from the pulley portions 52, 56 are applied to the region where the belt V is wound around the primary pulley 5, and gripping forces from the pulley portions 62, 66 are applied to the region where the belt V is wound around the secondary pulley 6.

The gripping force acts in a direction to displace the element 41 of the belt V radially outward of the rotation axes X1 and X2.

In the belt V, the elements 41 are restricted from radially outward displacement by rings 45, 45 inserted between the saddle surface 42a and the head 43.

Therefore, in the region where the belt V is wound around the primary pulley 5 and the secondary pulley 6, the side surfaces 420, 420 of the element 41 and the pulley surfaces 52a, 56a, 62a, 66a are brought into contact by a frictional force corresponding to the gripping force.

Thereby, torque transmission between the belt V and the primary pulley 5 and the secondary pulley 6 is performed.

During this torque transmission, the mountain portion 420a of the side surface 420 comes into contact with the pulley surfaces 52a, 56a, 62a, and 66a via an oil film in the region where the belt V is wound around the primary pulley 5 and the secondary pulley 6.

The groove 420b of the side surface 420 functions as a discharge path for discharging the lubricating oil in the longitudinal direction of the belt V.

As shown in fig. 2 (c), the head 43 of the element 41 is formed with a convex-shaped projection 431 on one surface. On the other surface, a concave hole 432 is formed which fits the projection 431 of the adjacent other element 41.

Referring to fig. 1, in the transmission mechanism 4, the rotational driving force input to the primary pulley 5 is changed in speed at a desired speed ratio by changing the winding radii of the belt V on the primary pulley 5 and the secondary pulley 6, and is transmitted to the secondary pulley 6.

The rotational driving force transmitted to the secondary pulley 6 is transmitted to the reduction gear RG. Reduction gear RG is provided rotatably about a rotation axis X3 parallel to rotation axis X2, and final gear FG of differential DEF meshes with reduction gear RG in a rotation-transmittable manner.

Therefore, the rotational driving force transmitted from the secondary pulley 6 to the reduction gear RG is transmitted to the differential DEF via the final gear FG. The drive shaft SH coupled to the differential DEF rotates about a rotation axis X4 parallel to the rotation axis X3, and a drive wheel (not shown) coupled to the drive shaft SH rotates by the transmitted rotational drive force.

The transmission case 7 of the continuously variable transmission 1 has: a case 8 having a housing chamber 80 of the transmission mechanism 4, a side cover 9 assembled to the case 8 to close an opening of the housing chamber 80, and a housing 10 for housing the torque converter TC.

Fig. 3 is a diagram illustrating the housing 8 of the continuously variable transmission 1. Fig. 3 (a) is a view of the case 8 viewed from the side cover 9 side. Fig. 3(b) is a view of the housing 8 as viewed from the upper side in the vertical direction with reference to the installation state of the continuously variable transmission 1.

As shown in fig. 3 (a), when the case 8 is viewed from the side cover 9 side, a cylindrical peripheral wall portion 82 surrounding the outer periphery of the transmission mechanism 4 is provided in the case 8.

The primary pulley 5 and the secondary pulley 6 are provided inside the peripheral wall portion 82 so as to be rotatable about the rotation axes X1, X2. Here, the rotation axes X1 and X2 are set parallel to each other with a gap inside the peripheral wall 82.

The peripheral wall 82 is provided with a plurality of bolt bosses 85 at intervals in the circumferential direction.

The inside of the peripheral wall portion 82 forms a housing chamber 80 of the transmission mechanism 4, and an opening of the housing chamber 80 is closed by a side cover 9 (see fig. 1).

The side cover 9 has a bolt boss 95 (see fig. 1) at a peripheral edge portion joined to an end surface of the side wall portion 81 (fig. 3 b) on the lower side of the paper surface. These bolt bosses 95 are provided at positions corresponding to the bolt bosses 85 on the case 8 side.

The side cover 9 is attached to the housing 8 by a bolt B (see fig. 1) in a state where a peripheral edge portion of the side cover 9 is joined to the peripheral wall portion 82 of the housing 8.

As shown in fig. 3(b), when the case 8 is viewed from the upper side in the vertical direction with respect to the installation state of the continuously variable transmission 1, the side cover 9 is fixed to the case 8 from the lower side in fig. 3 (b). Further, the housing 10 (see fig. 1) is fixed to the case 8 from the upper side of fig. 3 b.

The case 8 is also provided with a peripheral wall portion 83 surrounding the opening portion on the case 10 side, and the peripheral wall portion 83 is also provided with a plurality of bolt bosses 86 at intervals in the circumferential direction.

A boss portion 87 having a viewing hole 87a is provided in an area between the rotation axis X1 of the primary pulley 5 and the rotation axis X2 of the secondary pulley 6 in the upper side wall portion 81 of the housing 8 (fig. 3 (b)).

Fig. 4 is a view illustrating the observation hole 87a provided in the housing 8.

Fig. 4 (a) is a sectional view of the housing 8 taken along the line a-a in fig. 3 (b). Fig. 4 (b) is a perspective view of the case 8 viewed from below the oil pan side, and is an enlarged view of the area around the observation hole 87a of the case 8.

In fig. 4 (b), the rod-shaped inspection tool T inserted through the observation hole 87a is shown by a phantom line.

Fig. 5 is a view illustrating positioning grooves 871(871a, 871b), 872(872a, 872b) provided in the observation hole 87 a.

Fig. 5(a) is a sectional view of the case 8 taken along the line a-a in fig. 3(b), and shows the side of the tip Ta of the inspection tool T and the element 41 in phantom lines. Fig. 5 (b) is a sectional view taken along line a-a in fig. 5(a), and illustrates positioning of the inspection tool T by the positioning grooves 871 and 872. Fig. 5 (c) is a sectional view taken along line B-B in fig. 5(a), and illustrates positioning of the inspection tool T by the positioning grooves 871 and 872.

As shown in fig. 4 (a), the observation hole 87a is provided to penetrate the side wall portion 81 on the upper side of the housing 8 in the thickness direction.

On the outer surface of the housing 8, a boss portion 87 surrounding the observation hole 87a projects in a direction away from the side wall portion 81.

In the present embodiment, the peripheral wall portion 82 is located on the left side in fig. 4 a, the outer peripheral edge of the side cover 9 (see fig. 1) is attached to the peripheral wall portion 82, and the housing chamber 80 of the transmission mechanism 4 is formed between the case 8 and the side cover 9.

The observation hole 87a is formed with an opening D1 (see fig. 5) through which the inspection tool T can be inserted. The observation hole 87a is a through hole that communicates the housing chamber 80 in the housing 8 with the outside of the housing 8, and is provided substantially linearly inside the boss portion 87.

In the present embodiment, positioning grooves 871a, 871b, 872a, 872b are provided at one end and the other end of the observation hole 87 a.

In the observation hole 87a, positioning grooves 871a, 871b are provided at the ends inside the housing 8. In the observation hole 87a, positioning grooves 872a, 872b are provided at the end portions outside the housing 8.

The opening of the observation hole 87a is closed by the shaft portion of the bolt Ba (see fig. 4) screwed into the positioning grooves 872a, 872b of the observation hole 87 a.

As shown in fig. 5 (b), the observation hole 87a has a circular cross section, and the positioning grooves 871a and 871b are provided in a symmetrical positional relationship with the observation hole 87a interposed therebetween.

These positioning grooves 871a, 871b are located on a diametrical line L passing through the center of the observation hole 87 a. In the present embodiment, the diameter line L is set in such a direction as to cross the tape V in the width direction, and the diameter line L crosses the observation hole 87a in the width direction of the stacked elements 41.

The positioning grooves 871a and 871b are formed in the direction Ln (the longitudinal direction of the belt V) perpendicular to the diametrical line L with a predetermined width W1, and the width W1 is set to a width capable of engaging the inspection tool T.

As shown in fig. 5 (c), the positioning grooves 872a, 872b located on the outer side of the housing are also located on a diametrical line L passing through the center of the observation hole 87 a.

The positioning grooves 872a and 872b are also formed with a predetermined width W1 in a direction Ln perpendicular to the diameter line L, and the width W1 is set to a width capable of engaging the inspection tool T.

As shown in fig. 5a, the positions and ranges of the length L1 and the positioning grooves 871a, 871b, 872a, and 872b in the penetrating direction (vertical direction in fig. 5 a) of the observation hole 87a are set so as to satisfy the following conditions.

(a) The inspection tool T inserted through the observation hole 87a can be engaged with the positioning groove 871a and the other positioning groove 872b while being kept in a straight line.

Here, the "straight state" also means that the inspection tool T is not bent.

(b) The inspection tool T inserted through the observation hole 87a can be engaged with the positioning groove 871b and the other positioning groove 872a while being kept in a straight line.

(c) When the inspection tool T is engaged with the positioning groove 871a and the other positioning groove 872b, the distal end Ta of the inspection tool T is disposed at a position facing the one side surface 420 in the width direction of the component 41.

(d) When the inspection tool T is engaged with the positioning groove 871b and the other positioning groove 872a, the distal end Ta of the inspection tool T is disposed at a position facing the other side surface 420 in the width direction of the element 41.

In one embodiment, as shown in fig. 5(a), the positioning grooves 871a, 871b, 872a, 872b are respectively triangular.

Therefore, when the inspection tool T inserted through the observation hole 87a is positioned by the positioning grooves 871a, 871b, 872a, 872b, the distal end portion Ta of the inspection tool T can be quickly arranged at a position facing the side surface 420.

Fig. 6 is a diagram illustrating a positional relationship between the observation hole 87a and the belt V. Fig. 6 is a view showing the belt V disposed inside the side wall portion 81 in a state where the case 8 is viewed from above.

In the continuously variable transmission 1, the transmission ratio of the rotational driving force input to the variator 4 is changed by changing the winding radius of the belt V of a pair of pulleys (the primary pulley 5 and the secondary pulley 6) constituting the variator 4.

In the primary pulley 5, the winding radius of the belt V is changed by displacement of the movable pulley 55 in the direction of the rotation axis X1.

In the secondary pulley 6, the winding radius of the belt V is changed by displacement of the movable pulley 65 in the direction of the rotation axis X2.

Therefore, in the transmission mechanism 4, the winding position of the belt V of the primary pulley 5 and the winding position of the belt of the secondary pulley 6 are displaced in the directions of the rotation axes X1 and X2 according to the transmission gear ratio, respectively.

Here, the belt V wound around the pair of pulleys (the primary pulley 5 and the secondary pulley 6) has the largest displacement amount on the rotation axis X1 side of the primary pulley 5 and the rotation axis X2 side of the secondary pulley 6 (refer to fig. 6 and belt vibration).

The substantially intermediate position between the rotary shaft X1 and the rotary shaft X2 arranged in parallel to each other is the substantially intermediate position, and the displacement amount (core shift) is the smallest in the range of the speed ratio achievable by the continuously variable transmission 1.

The region of the belt V located at this intermediate position is not wound around the pair of pulleys (primary pulley 5, secondary pulley 6). In the region of the belt V located at the intermediate position, the side surfaces 420 of the element 41 are exposed on both sides in the width direction of the belt V.

As described above, in the present embodiment, in the side wall portion 81 on the upper side of the housing 8, the observation hole 87a is provided in the area between the rotation axis X1 of the primary pulley 5 and the rotation axis X2 of the secondary pulley 6.

The outer periphery of the region where the amount of displacement in the direction of the rotation axes X1 and X2 of the belt V is the smallest (the region of the belt V located at the intermediate position) is located on the extension line in the penetrating direction of the observation hole 87 a.

As described above, the observation hole 87a is formed to a depth such that the tip Ta side of the inspection tool T inserted from the observation hole 87a can be disposed to one side and the other side in the width direction of the belt V.

Further, in the observation hole 87a, positioning grooves 871a, 871b, 872a, 872b are provided at the inner end and the outer end of the case 8.

Further, when the inspection tool T is engaged with the positioning groove 871a and the positioning groove 872b, or the positioning groove 871b and the positioning groove 872a, the distal end portion Ta of the inspection tool T can be set to a position facing the one side surface 420 or the other side surface 420 of the component 41.

Here, the inspection tool T includes a fiberscope and a CCD camera. In the present embodiment, a rod-shaped inspection tool T having a camera provided at the distal end portion Ta is used.

Therefore, the positioning grooves 871 and 872 allow the distal end portion Ta of the inspection tool T to be quickly disposed at a position facing the side surface 420.

Further, in the case 8, the observation hole 87a is opened at a position above the oil surface of the lubricating oil in the transmission case 7 along a vertical line direction with respect to the installation state of the continuously variable transmission 1.

Therefore, even if the bolt Ba that closes the observation hole 87a is removed in order to insert the inspection tool T into the case 8 at the time of inspecting the belt V, the lubricating oil in the transmission case 7 does not leak to the outside.

As described above, the continuously variable transmission 1 of the present embodiment has the following configuration.

(1) The belt type continuously variable transmission 1 includes: a transmission mechanism 4 configured by winding a belt V around a pair of pulleys (a primary pulley 5 and a secondary pulley 6), and a transmission case 7 (a case 8, a side cover 9, and an outer case 10) having a housing chamber 80 of the transmission mechanism 4.

In the continuously variable transmission 1, a desired speed ratio is realized by changing the winding radius of the belt V of each of the pair of pulleys (the primary pulley 5 and the secondary pulley 6).

The housing chamber 80 has a peripheral wall portion (a side wall portion 81, a peripheral wall portion 82) surrounding the outer periphery of the transmission mechanism 4.

The pair of pulleys (primary pulley 5, secondary pulley 6) are rotatably provided inside the peripheral wall portion 82 around a pair of rotation shafts X1, X2 set in parallel with each other at intervals.

The pulleys (primary pulley 5, secondary pulley 6) have: fixed pulleys 51, 61, and movable pulleys 55, 65 displaceable in the directions of rotation axes X1, X2.

The winding radius of the belt V on the pulleys (primary pulley 5, secondary pulley 6) is changed by displacement of the movable pulleys 55, 65 in the directions of the rotation axes X1, X2.

The belt V has: the element 41 is stacked and arranged in a ring shape, and the ring 45 bundles the stacked elements 41.

Element 41 has side surfaces 420, 420 gripped by fixed pulleys 51, 61 and movable pulleys 55, 65, respectively, on both sides in the width direction.

The peripheral wall 82 is provided with an observation hole 87a through which the side surfaces 420 and 420 can be observed.

With the above configuration, the side surfaces 420 and 420 of the element 41 constituting the band V can be observed, and it can be appropriately confirmed that there is no damage to the side surfaces 420 and 420.

The continuously variable transmission 1 of the present embodiment has the following configuration.

(2) The side surfaces 420 and 420 of the element 41 are regions gripped by the sheave surfaces 52a and 62a of the fixed sheaves 51 and 61 and the sheave surfaces 56a and 66a of the movable sheaves 55 and 65, respectively.

The side surfaces 420 and 420 are provided with a peak portion 420a that contacts the sheave surfaces 52a and 62a of the fixed pulleys 51 and 61 or the sheave surfaces 56a and 66a of the movable pulleys 55 and 65 via an oil film, and a groove portion 420b that discharges the lubricating oil OL in the element stacking direction.

The ridge portions 420a and the groove portions 420b are formed to be alternately arranged in the thickness direction of the belt X (the radial direction of the rotation axes X1, X2).

With the above configuration, the wear of the peak portions 420a and the groove portions 420b provided in the side surfaces 420 and 420 can be appropriately checked.

The continuously variable transmission 1 of the present embodiment has the following configuration.

(3) The winding position of the belt V with respect to the primary pulley 5 and the winding position of the belt V with respect to the secondary pulley 6 are displaced in the directions of the rotation axes X1 and X2 in accordance with the gear ratio of the continuously variable transmission 1.

The observation hole 87a is provided in the peripheral wall 82 at a position where a region where displacement in the direction of the rotation axes X1, X2 of the tape V is smallest can be observed.

When the observable region of the belt V is a region that is greatly displaced in the direction of the rotation axes X1, X2 in accordance with the gear ratio, the observation hole needs to be formed to be enlarged in the displacement direction of the belt V in order to appropriately observe the belt V.

If the observation hole is enlarged, the rigidity of the case 8 is lowered, and the processing cost is increased.

If the observation hole 87a is provided at a position where a region where displacement in the direction of the rotation axes X1, X2 of the tape V is smallest can be observed, the size of the observation hole 87a can be suppressed. This makes it possible to appropriately confirm whether or not the band is intact while suppressing the size of the observation hole. It is possible to appropriately prevent a decrease in the rigidity strength of the case 8 and an increase in the processing cost.

The continuously variable transmission 1 of the present embodiment has the following configuration.

(4) The region where the displacement of the belt V in the directions of the rotation axes X1 and X2 is the smallest is a region where the belt V is not wound around the pulleys (the primary pulley 5 and the secondary pulley 6).

In the areas of the belt V not wound around the pulleys (primary pulley 5, secondary pulley 6), the side surfaces 420, 420 of the element 41 are exposed.

Therefore, the wear of the mountain portion 420a and the groove portion 420b provided in the side surface 420 can be appropriately confirmed.

The continuously variable transmission 1 of the present embodiment has the following configuration.

(5) The outer peripheries of the regions where the displacements in the directions of the rotation axes X1 and X2 of the belt V are smallest are located on the extension line of the observation hole 87 a.

The observation hole 87a is formed so that the distal end portion Ta of the inspection tool T inserted from the observation hole 87a can be disposed at a depth L1 between one side and the other side in the width direction of the belt V.

When it is confirmed that the tape V is not damaged, an inspection tool (a fiberscope, a CCD camera, etc.) is inserted through the observation hole 87 a.

At this time, if the inserted inspection tool T is held in a position in contact with the opening end of the inner periphery of the case 8 opened to the observation hole 87a and the opening end of the outer periphery of the case 8, the tip end Ta side of the inspection tool T can be arranged in a position facing one side surface 420 in the width direction of each element 41 or in a position facing the other side surface 420.

Thus, by providing a camera for observation or the like on the side of the distal end portion Ta of the inspection tool T, it is possible to appropriately confirm whether or not the one side surface 420 and the other side surface 420 in the width direction of each element 41 are worn.

The continuously variable transmission 1 of the present embodiment has the following configuration.

(6) In the observation hole 87a, positioning grooves 871a and 872b of the inspection tool T are provided at least at the end portions opened on the inner side of the housing 8.

The positioning grooves 871a, 871b are provided in a pair in a symmetrical positional relationship on a diametrical line L in the width direction of the belt V as viewed in the penetrating direction of the observation hole 87 a.

According to the above configuration, when the inspection tool T is positioned in the positioning groove 871a, the tip Ta side of the inspection tool T inserted from the observation hole 87a can be disposed on one side in the width direction of the belt V. Further, when the inspection tool T is positioned in the other positioning groove 871b, the tip Ta side of the inspection tool T inserted from the observation hole 87a can be disposed on the other side in the width direction of the belt V.

This enables the inspection tool T to be quickly arranged at a position suitable for observing one side surface 420 and at a position suitable for observing the other side surface 420 of each element 41 in the width direction.

The continuously variable transmission 1 of the present embodiment has the following configuration.

(7) In the case 8 of the transmission case 7, the observation hole 87a is opened at a position above the oil surface of the lubricating oil OL in the transmission case 7 in the vertical line direction with respect to the installation state of the continuously variable transmission 1.

According to the above configuration, even if the bolt Ba (cap) that closes the opening of the observation hole 87a is removed in order to insert the inspection tool T into the observation hole 87a, the lubricant OL in the transmission case 7 does not leak from the observation hole 87 a.

Thus, the presence or absence of the damage of the belt V can be confirmed more easily because the lubricant OL in the transmission case 7 does not need to be drained every time the presence or absence of the damage of the belt V is confirmed.

The embodiments of the present invention have been described above, but the present invention is not limited to the above embodiments. Appropriate changes can be made in the technical idea of the invention of the present application.