JP2012077866A - Transmission belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transmission belt that can suppress or prevent a drag loss by reducing inflow or retention of oil in a clearance between a ring and an element.SOLUTION: The transmission belt 6 in which a plurality of elements 8 annularly arranged in a lined-up attitude is bound with a ring 7, each element 8 being formed with a saddle surface 9b contacted with an inner peripheral surface of the endless ring 7 and a hook part 13 arranged on an outer peripheral side of the ring 7 by facing a part of the saddle surface 9b, which forms a slit with a width wider than the thickness of the ring 7 and depth shallower than the width of the ring 7, has a configuration to remove oil in the clearance between an outer peripheral surface 7b of the ring 7 and the hook part 13.

Description

  The present invention relates to a transmission belt that is composed of a ring and a plurality of elements bound by the ring and is wound around a pair of pulleys to transmit power, and in particular, friction between the ring and element or friction between elements or element. The present invention relates to a transmission belt using oil that reduces friction between the pulley and the pulley.

  Conventionally, a transmission belt composed of a ring and an element fitted to the ring is known. A transmission belt used in an automobile or a machine that requires high output torque has a large tensile load on the ring and the element. Since a compressive load acts, any member uses a metal material having high tensile and compressive strength. In addition, since the ring member is bent at the place where it is wound around the pulley and is pulled between the pulleys, it is used by laminating a plurality of thin rings to adapt to bending and pulling deformation. Has been.

  Therefore, since each member is made of a metal material, the tensile and compressive strength of each member increases, but when transmitting power, the members of the metal material inevitably come into contact with each other. There is a possibility that frictional heat is generated by the contact, or wear is caused and durability is lowered.

  Therefore, in the invention described in Patent Document 1, in order to improve durability and power transmission efficiency of a transmission belt composed of a stacked ring and a plurality of elements bound by the ring, the pitching of elements ( The element is configured to prevent contact between the element and the ring due to the element rotating and tilting about an axis along the longitudinal direction of the ring. In other words, by forming a large gap between the outer peripheral surface of the stacked ring and the element, when the element is tilted due to pitching or the like, the elements are connected to each other before the outer peripheral surface of the ring contacts the element. For this purpose, the convex portion and the concave portion that are formed are in contact with each other.

  Moreover, in the invention described in Patent Document 2, a PTFE (polytetrafluoroethylene resin) coating is applied to the surface of the ring in order to reduce contact friction between the element and the ring.

JP 2001-200894 A JP 2000-193042 A

  According to the invention described in Patent Document 1 described above, by increasing the gap between the element and the ring, even when the element is tilted by pitching or the like, the convex portion and the concave portion formed and coupled to each element are combined. Since the contact between the element and the ring can be prevented, the durability of the ring can be improved. However, since the pulley that contacts the element or ring or the element and transmits power is made of a metal material, even if the contact between the outer peripheral surface of the ring and the element is prevented, contact with other parts or the pulley Lubrication is required at the contact area. Therefore, the lubricating oil is supplied by immersing a part of the transmission belt in the oil or dropping the oil on the transmission belt. As a result, when slipping occurs between the outer peripheral surface of the ring and the element in a state where the lubricating oil stays in the clearance between the outer peripheral surface of the ring and the element, the viscous resistance of the oil remaining in the clearance As a result, the transmission efficiency may be reduced.

  Moreover, according to the invention described in Patent Document 2, the contact resistance between the surface of the ring on which the coating is applied and the element can be reduced by applying PTFE coating on the entire surface of the ring. In addition, since the coated surface has oil repellency and can suppress the adhesion of oil, the viscosity resistance of the oil can be reduced. However, since oil may stay in the gap between the ring and the element, there is a possibility that a considerable oil drag loss occurs.

  The present invention pays attention to the above-described technical problem, and can reduce or prevent drag loss by reducing or preventing oil from flowing into or remaining in the gap between the ring and the element. Is intended to provide.

  In order to achieve the above object, according to the first aspect of the present invention, a plurality of elements arranged in an annular shape with the same posture are bound by a ring, and each element is in contact with an inner peripheral surface of an endless ring. A saddle surface and a hook portion which is provided on the outer peripheral side of the ring so as to face a part of the saddle surface and form a slit wider than the thickness of the ring and shallower than the width of the ring are formed. In the transmission belt, the oil in the gap between the outer peripheral surface of the ring and the hook portion is removed from the gap.

  According to a second aspect of the present invention, in the configuration of the first aspect, the oil repellency of a portion of the outer peripheral surface of the ring that is inserted into the hook portion and faces the hook portion is the outer peripheral surface of the ring. It is a transmission belt characterized by being formed higher than the oil repellency of the part which protrudes from the hook part.

  According to a third aspect of the present invention, in the configuration of the first or second aspect, an oil repellent treatment is applied to a portion of the outer peripheral surface of the ring that is inserted into the hook portion and faces the hook portion, and the ring The transmission belt is characterized in that the oil-repellent treatment is not applied to a portion protruding from the hook portion of the outer peripheral surface of the belt.

  According to a fourth aspect of the invention, there is provided the transmission belt according to the third aspect, wherein the oil-repellent treatment includes any one of a surface treatment with a fluorine-based surface treatment agent and a formation of a coating layer with a fluorine-based resin. is there.

  According to the first aspect of the present invention, the oil staying in the gap between the outer peripheral surface of the ring and the hook portions of the plurality of elements bound by the ring is configured to be removed from the gap. Oil does not stay in the gap between the outer peripheral surface and the hook portion of the element, and as a result, viscous resistance or drag loss due to the sliding speed between the ring and the element can be suppressed or prevented. Reduction in transmission performance can be suppressed or prevented.

  Further, according to the inventions of claims 2 to 4, a surface treatment with a fluorine-based surface treatment agent and a coating with a fluorine-based resin are applied to a portion of the outer peripheral surface of the ring which is inserted into the hook portion and faces the hook portion. Any oil repellency treatment of the layer is applied, and the part protruding from the hook portion on the outer peripheral surface of the ring is not subjected to oil repellency treatment, so it stays in the gap between the outer peripheral surface of the ring and the hook portion The oil that has been or has flowed in can be removed to the outer peripheral surface side of the ring protruding from the hook portion due to the difference in oil repellency. Therefore, similarly to the effect of the invention of claim 1, it is possible to suppress or prevent the viscous resistance or drag loss caused by the sliding speed between the ring and the element, thereby suppressing or preventing the reduction of the transmission performance of the transmission belt. be able to.

It is a front view which shows an example of the power transmission belt which concerns on this invention. It is the schematic which shows an example of the belt-type continuously variable transmission which can utilize the power transmission belt which concerns on this invention. It is a perspective view which shows an example of the power transmission belt which concerns on this invention. It is a graph which shows the difference in the loss of power transmission by the difference in the temperature of oil. It is a graph which shows the relationship between a gear ratio and a sliding speed. It is the schematic which shows a part of element shown in FIG. 1, and the outer peripheral surface of a lamination | stacking ring. It is the schematic for demonstrating the flow of the oil of the outer peripheral surface of a lamination | stacking ring.

  Next, in order to describe the transmission belt according to the present invention, the configuration of a belt-type continuously variable transmission that can use the transmission belt will be briefly described with reference to FIG. The basic configuration of the belt-type continuously variable transmission 1 shown in FIG. 2 is conventionally known, and includes a primary pulley 3 connected to the input shaft 2 and an output shaft 4 arranged in parallel with the input shaft 2. And a belt 6 wound around the pulleys 3 and 5. The pulleys 3 and 5 are arranged so as to face the fixed sheaves 3a and 5a formed integrally with the input shaft 2 or the output shaft 4 and the fixed sheaves 3a and 5a. The movable sheaves 3b and 5b are movable along the axis. Therefore, by moving the movable sheave 3b (5b) of one pulley 3 (5), the groove width of the pulley 3 (5) is changed, the winding radius of the belt 6 is changed, and the other pulley 5 (3) ), The belt 6 can be tensioned by applying a load to the fixed sheave 5a (3a) side by the movable sheave 5b (3b).

  On the other hand, as shown in FIG. 3, the belt 6 has a laminated ring 7 formed by laminating metal rings 7a in the thickness direction, and is arranged in an annular shape so as to be aligned in the longitudinal direction of the laminated ring 7. 7 and a plurality of metal elements 8 and 8 bound together. The element 8 is sandwiched between the pulleys 3 and 5 so that power is transmitted by the frictional force between the pulleys 3 and 5 and the element 8. Accordingly, the side wall surface of the element 8 (hereinafter referred to as the flank surface 9a) is formed at the same angle as the angle of the pulley surface where the sheaves 3a and 3b (5a and 5b) face each other.

  Therefore, when the primary pulley 3 rotates, the torque of the primary pulley 3 is transmitted to the element 8, and the power is transmitted when the element 8 contacts or pushes the other element 8 or compresses, and Torque is transmitted from the element 8 to the secondary pulley 5.

  Further, the laminated ring 7 has a tension at the entrance of the primary pulley 3, that is, a portion where the primary pulley 3 starts to be wound, and a tension at the exit of the primary pulley 3, that is, a portion where the state of being wound around the primary pulley 3 ends. The power is transmitted by the tension difference between the two.

  Here, an example of the configuration of the transmission belt according to the present invention will be specifically described with reference to FIG. The element 8 shown in the figure has a main body part 9 (lower part shown in the figure) provided with a flank surface 9a to which power is transmitted in contact with the pulleys 3 and 5, and from the center in the width direction of the main body part 9 upward The neck portion 10 is formed and a substantially triangular head portion 11 formed above the neck portion 10. Further, the width of the head 11 is formed to be narrower than the width of the main body 9. In other words, in a state where the element 8 is sandwiched between the pulleys 3 and 5, the pulleys 3 and 5 are configured not to come into contact with any part other than the flank surface 9 a of the main body 9. Furthermore, the plate | board thickness of the lower part in the main-body part 9 is formed thinner than the plate | board thickness of an upper part. This is to allow the element 8 to pitch when the element 8 receives power from the pulleys 3 and 5 or when the element 8 is wound around the pulleys 3 and 5. That is, if the pitching of the element 8 is not allowed, the frictional resistance between the element 8 and the laminated ring 7 is increased, and the durability of the element 8 and the laminated ring 7 is reduced. And it is comprised so that motive power may be transmitted when the rocking edge 12 which is a boundary line of the upper part of the main-body part 9 and a lower part contacts and pushes the element 8 located ahead of the element 8. .

  Moreover, the convex part 11a which protruded in the thickness direction in the center in the width direction of the head 11 and the recessed part depressed in the thickness direction on the opposite surface in the thickness direction of the position where the convex part 11a is formed 11b. The convex portion 11a and the concave portion 11b are configured to be fitted in order to restrain the elements 8, 8 from each other, or to suppress or restrict the movement of the element 8. That is, the inner diameter of the concave portion 11b is slightly larger than the outer shape of the convex portion 11a.

  The upper surface (hereinafter referred to as saddle surface 9b) of the main body 9 of the element 8 configured as described above and the laminated ring 7 have a large contact area in order to improve power transmission performance and durability. As shown in the figure, the laminated ring 7 is disposed in contact with the entire saddle surface 9b. Further, the hook portion 13 protruding from the neck portion 10 in the width direction of the head 11 is provided to prevent the laminated ring 7 from coming off or falling off from the element 8, and is larger than the width of the laminated ring 7. The gap between the saddle surface 9 b and the hook portion 13 is formed to be narrower than the thickness of the laminated ring 7.

  Since the element 8 is positioned in the radial direction of the pulleys 3 and 5 based on the groove width of the pulleys 3 and 5, and the tension is applied to the laminated ring 7, the element 8 is connected to the belt-type continuously variable transmission 1. When power is transmitted, the inner peripheral surface of the laminated ring 7 is in contact with the saddle surface 9b. Further, in order to prevent an increase in frictional resistance due to contact between the laminated ring 7 and the hook portion 13, a predetermined gap is formed between the outer peripheral surface 7 b of the laminated ring 7 and the hook portion 13. The predetermined gap is a gap that does not contact the hook portion 13 of the element 8 and the outer peripheral surface 7b of the laminated ring 7 even when the element 8 is pitched.

  On the other hand, the belt-type continuously variable transmission 1 configured as described above is supplied with lubricating oil in order to reduce the frictional resistance between the elements 8 and 8 and between the element 8 and the pulleys 3 and 5. Accordingly, the lubricating oil flows into the gap between the hook portion 13 of the element 8 and the outer peripheral surface 7 b of the laminated ring 7. As a result, at a portion where the metal belt 6 is wound around the pulleys 3 and 5, oil drag loss is caused by a speed difference (sliding speed V) between the hook portion 13 of the element 8 and the outer peripheral surface 7b of the laminated ring 7. Arise.

The sliding speed V between the hook portion 13 of the element 8 and the outer peripheral surface 7b of the laminated ring 7 can be obtained by the following equation 1.
(Formula 1)
V = 2πω · h · | (1 / i) −1 | · (1/60)
In Equation 1, ω is the rotational speed, h is the gap between the hook portion 13 and the outer peripheral surface 7b of the laminated ring 7, and i is the gear ratio.

Further, the oil drag loss τ (or the shearing force of the oil) can be obtained by the following equation 2.
(Formula 2)
τ = μ · (V / h)
Note that μ in Equation 2 is the viscosity coefficient of oil. Therefore, since the drag loss τ of oil is proportional to the viscosity coefficient of the oil, the transmission performance of the belt 6 is particularly reduced when the oil is at a low temperature. FIG. 4 shows the difference in drag loss between the case where the oil temperature is room temperature and the case where the oil temperature is about 80 ° C. In addition, the case where the oil temperature is the same as the room temperature is shown by a rhombus, and the case where the oil temperature is 80 ° C. is shown by a triangle.

  As can be seen from the equations 1 and 2, the slip velocity V increases in proportion to the rotational speed of the pulleys 3 and 5, and the drag loss τ of oil increases in proportion to the slip velocity V. In addition, the graph which shows the relationship between the gear ratio i and the sliding speed V is shown in FIG.

  Since the oil flows into and stays in the gap between the hook portion 13 and the outer peripheral surface 7b of the laminated ring 7 as described above, the transmission performance of the belt 6 is deteriorated. As shown in FIG. 6, the outer peripheral surface 7b of the laminated ring 7 is made of a fluorine-based material such as fluoroalkylsilane having high oil repellency or a polytetrafluoroethylene which is a fluorine-based resin. Oil-repellent treatment is applied by surface treatment. That is, the surface 7b that is inserted into the hook portion 13 of the outer peripheral surface of the laminated ring 7 and faces the hook portion 13 is subjected to oil repellent treatment, and the outer peripheral surface 7c of the laminated ring 7 protruding from the hook portion 13 is applied. Is configured not to be subjected to oil repellent treatment.

  As described above, the oil repellent treatment is performed on the outer peripheral surface 7 b of the laminated ring 7, whereby drag loss of oil flowing into the gap between the outer peripheral surface 7 b of the laminated ring 7 and the hook portion 13 can be suppressed or prevented. Further, by not subjecting the outer peripheral surface 7c of the laminated ring 7 not inserted into the hook portion 13 to the oil repellent treatment, as shown in FIG. 7, the outer peripheral surface 7b of the laminated ring 7 and the hook portion 13 of the element 8 The oil that has flowed into the gap is removed by suction or flow out to the outer peripheral surface 7c on the side not subjected to the oil repellent treatment due to the difference in oil repellency. Accordingly, the oil that has flowed into the gap can be forcibly drawn out or removed to the outer peripheral surface 7c that has not been subjected to the oil-repellent treatment. Can be suppressed or prevented.

  As described above, the oil repellent treatment is applied to the surface 7 b that is inserted into the hook portion 13 on the outer peripheral surface of the laminated ring 7 and faces the hook portion 13, and the oil repellent treatment is applied to the outer peripheral surface 7 c protruding from the hook portion 13. The oil drag loss due to the oil staying in the gap between the laminated ring 7 and the hook portion 13 can be efficiently reduced.

  The present invention is not limited to the above-described configuration. For example, even when the configuration of the element 8 is different, the oil is dragged by the oil remaining in the gap between the element 8 and the laminated ring 7. It can be applied to places where loss occurs. In addition, the surface of the hook portion 13 of the element 8 facing the laminated ring 7 may be subjected to oil repellency treatment.

  6 ... belt, 7 ... laminated ring, 7b, 7c ... outer peripheral surface of laminated ring, 8 ... element, 13 ... hook part.

Claims (4)

A plurality of elements arranged in an annular shape with the same posture are bundled by a ring, and each element has a saddle surface that contacts an inner peripheral surface of an endless ring, and a portion of the saddle surface facing the saddle surface. In the transmission belt formed on the outer peripheral side of the ring and formed with a hook portion that forms a slit wider than the thickness of the ring and shallower than the width of the ring,
A power transmission belt comprising a configuration for removing oil in a gap between an outer peripheral surface of the ring and the hook portion from the gap.   The oil repellency of the portion of the outer peripheral surface of the ring that is inserted into the hook portion and faces the hook portion is higher than the oil repellency of the portion of the outer peripheral surface of the ring protruding from the hook portion. The transmission belt according to claim 1, wherein the transmission belt is provided.   An oil repellent treatment is applied to a portion of the outer peripheral surface of the ring that is inserted into the hook portion and faces the hook portion, and a portion protruding from the hook portion of the outer peripheral surface of the ring The transmission belt according to claim 1 or 2, wherein an oil repellent treatment is not performed.   The transmission belt according to claim 3, wherein the oil repellent treatment includes any one of a surface treatment with a fluorine-based surface treatment agent and a formation of a coating layer with a fluorine-based resin.

Images