JP2018184982A - Oil temperature raising device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oil temperature raising device capable of enhancing temperature raising of an oil.SOLUTION: A temperature raising device 1 includes a driven gear 5 housed in a case 9 and disposed on a rotary shaft 6, a frictional material 11 disposed on an outer race 7a of a bearing 7, a disc spring 10 disposed on a side portion of the driven gear 5, and kept into contact with the frictional material 11 when a space between the side portion and the frictional material 11 is a prescribed space or less, and a shape memory alloy 12 expanded at least in an axial direction of the rotary shaft 6 at a prescribed temperature or more. The driven gear 5 is a helical gear, thrust force of the driven gear 5 is generated in a direction of a bearing 7 side in coast traveling of an electric automobile, the case 9 has a coefficient of linear expansion larger than that of the rotary shaft 6, the case 9 is expanded more than the rotary shaft 6 in the axial direction of the rotary shaft 6 in accompany with temperature raising, and the space between the side portion of the driven gear 5 and the frictional material 11 becomes larger than the prescribed space by the shape memory alloy 12 at the prescribed temperature or more.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an oil temperature raising device used in a vehicle or the like.

  For example, in a vehicle, power is transmitted through various gears. Patent Document 1 includes a reduction gear including a driving helical gear splined to the rotor shaft of an electric motor and a driven helical gear meshed with the helical gear. An electric vehicle is disclosed that transmits power generated by an electric motor to drive wheels. Lubrication of a vehicle speed reducer or the like is performed, for example, by immersing a gear constituting the speed reducer or the like in oil (lubricating oil) and scooping up and scattering the oil by rotation of the gear.

Japanese Patent Laid-Open No. 2004-50886

  By the way, when the vehicle is cold, the oil temperature is low and the oil viscosity is high. When high-viscosity oil is used for lubrication, friction loss increases (for example, the stirring resistance when the gear scoops up the oil increases), and the fuel consumption of the vehicle decreases. Therefore, it is necessary to raise the temperature of the oil. In particular, in the case of an electric vehicle as disclosed in Patent Document 1, it is not possible to raise the temperature of the oil using the heat generated in the engine, so that it takes time to raise the oil as compared to a vehicle equipped with the engine. Therefore, it is desired to promote the temperature rise of the oil.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an oil temperature raising device capable of promoting the temperature rise of oil.

  An oil temperature increasing device according to the present invention is housed in a case and provided on a rotary shaft supported by a bearing attached to the case, and at least one side in the axial direction of the rotary shaft of the gear. A contact member that is in contact with the non-rotating part when the distance between the one side of the gear and the non-rotating part in the case is equal to or less than a predetermined distance, and the gear is in a state where torque is applied. The thrust force of the gear is generated in the direction of the non-rotating part when torque is applied to the gear in one direction, and the case has a linear expansion larger than that of the rotating shaft. It has a coefficient and is characterized in that it expands more than the rotating shaft at least in the axial direction of the rotating shaft as the temperature rises.

  In the oil temperature raising apparatus according to the present invention, a thrust force is generated in the direction of the non-rotating portion while the rotating shaft (gear) is rotating in one direction. Pressed against the rotating part, and the pressed contact member comes into contact with the non-rotating part. As a result, differential rotation occurs between the contact member that rotates together with the gear and the non-rotating portion, and frictional heat is generated. This generated heat raises the temperature of the oil. Thereby, the viscosity of oil becomes low, for example, the stirring resistance at the time of a gear scooping up oil can be reduced. Further, when the case, the rotating shaft, etc. are heated by the generated heat, the case having a large linear expansion coefficient expands in the axial direction relative to the rotating shaft. When this expansion difference becomes large, the distance between the one side of the gear and the non-rotating part in the case becomes larger than a predetermined distance, and the contact member does not contact the non-rotating part. Thus, according to the oil temperature raising apparatus according to the present invention, it is possible to promote the temperature rise of the oil when the temperature is low.

  In the oil temperature increasing device according to the present invention, the oil temperature increasing device is provided between the one side portion of the gear and the rotating portion that rotates along with the rotating shaft, and increases at least in the axial direction of the rotating shaft when the temperature exceeds a predetermined temperature. A temperature-sensitive deformation member is provided, and when the temperature-sensitive deformation member becomes larger in the axial direction of the rotating shaft, the temperature-sensitive deformation member causes the gap between the one side of the gear and the non-rotating portion in the case to be a predetermined distance. It is preferable that it becomes larger. With this configuration, when the temperature of the temperature-sensitive deformation member becomes equal to or higher than a predetermined temperature due to the frictional heat described above, the temperature-sensitive deformation member becomes larger in the axial direction of the rotating shaft, so that one side of the gear Since the interval between the portion and the non-rotating portion in the case becomes larger than the predetermined interval, the contact member does not reliably contact the non-rotating portion.

  An oil temperature increasing device according to the present invention is housed in a case and provided on a rotary shaft supported by a bearing attached to the case, and at least one side in the axial direction of the rotary shaft of the gear. A contact member that comes into contact with the non-rotating part when the distance between the one side part of the gear and the non-rotating part in the case is equal to or less than a predetermined distance, and the one side part of the gear and the rotating shaft. And a temperature-sensitive deformable member that increases at least in the axial direction of the rotating shaft when the temperature exceeds a predetermined temperature, and the gear is thrust when torque is applied. The gear's thrust force is generated in the direction of the non-rotating part when torque is applied to the gear in one direction, and the temperature-sensitive deformation member increases in the axial direction of the rotating shaft. If temperature-sensitive deformation Distance between the non-rotating portion of the one side of the side and the case of the gear is equal to or larger than a predetermined interval by wood.

  In the oil temperature raising apparatus according to the present invention, a thrust force is generated in the direction of the non-rotating portion while the rotating shaft (gear) is rotating in one direction. The frictional heat is generated by the differential rotation between the pressed contact member and the non-rotating part. This generated heat raises the temperature of the oil. Further, when the temperature of the temperature-sensitive deformation member becomes equal to or higher than a predetermined temperature due to the generated heat, the temperature-sensitive deformation member becomes larger in the axial direction. When the increased temperature-sensitive deformation member causes the gap between the one side portion of the gear and the non-rotating portion in the case to be larger than a predetermined interval, the contact member does not contact the non-rotating portion. Thus, according to the oil temperature raising apparatus according to the present invention, it is possible to promote the temperature rise of the oil when the temperature is low.

  In the oil temperature raising apparatus according to the present invention, the contact member is preferably an elastic member. In particular, the contact member is preferably a disc spring. By using a contact member that is elastically deformed with respect to the load (thrust force of the gear), the contact member is pressed against the non-rotating portion by the thrust force, and the pressed contact member comes into contact with the non-rotating portion while being elastically deformed. be able to. In particular, by using a disc spring, it is elastically deformed non-linearly with respect to the load. Therefore, it is possible to easily adjust the axial length of the contact member that changes from the contact state to the non-contact state with respect to the non-rotating portion. .

  The oil temperature raising apparatus according to the present invention is preferably provided in a vehicle, and the thrust force of the gear is preferably generated in the direction toward the non-rotating portion when the vehicle is coasting. With this configuration, it is possible to reduce the friction by promoting the temperature rise of the oil when the vehicle is coasting. During drive driving of the vehicle, the thrust force of the gear is generated in the direction opposite to the non-rotating part, so that the contact member does not contact the non-rotating part and the driving torque is not lost.

  In the oil temperature raising apparatus according to the present invention, the vehicle is preferably an electric vehicle. With this configuration, it is possible to promote the temperature rise of oil in an electric vehicle that does not include an engine.

  In the oil temperature raising apparatus according to the present invention, it is preferable that the non-rotating portion is provided with a friction material, and the contact member is in contact with the friction material provided in the non-rotating portion. By comprising in this way, when a contact member contacts a friction material, heat can be efficiently generated by friction and the temperature rise of oil can be promoted.

  In the oil temperature raising apparatus according to the present invention, the non-rotating portion is preferably an outer race of the bearing. In this way, a non-rotating portion can be configured using a part of the bearing, and differential rotation can be generated between the contact member that rotates together with the gear and the outer race that does not rotate.

  In the oil temperature raising apparatus according to the present invention, the rotating part is preferably an inner race of the bearing. In this way, a rotating part can be configured by using a part of the bearing, and no differential rotation occurs between the inner race that rotates together with the rotating shaft and the one side part of the gear, and the temperature-sensitive deformation member in the meantime. Can be arranged.

  In the oil temperature raising apparatus according to the present invention, the temperature-sensitive deformation member is preferably a shape memory alloy. By using the shape memory alloy, the contact member does not come into contact with the non-rotating portion because the shape memory alloy returns to the original shape (becomes larger) when the temperature exceeds a predetermined temperature.

  According to the present invention, it is possible to promote the temperature rise of oil.

It is sectional drawing of the temperature rising apparatus of the oil which concerns on 1st Embodiment. It is a perspective view of the disc spring of the oil temperature rising apparatus which concerns on 1st Embodiment. It is a graph which shows the elastic deformation characteristic of the disc spring of the oil temperature rising apparatus which concerns on 1st Embodiment. It is a figure which shows typically the state in temperature rising by the oil temperature rising apparatus which concerns on 1st Embodiment. It is a figure which shows typically the state after the temperature rising by the oil temperature rising apparatus which concerns on 1st Embodiment. It is sectional drawing of the temperature rising apparatus of the oil which concerns on 2nd Embodiment. It is a perspective view of the contact member of the oil temperature rising apparatus which concerns on 2nd Embodiment. It is sectional drawing which shows an example of the other form of the temperature rising apparatus of oil.

  DESCRIPTION OF EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same reference numerals are used for the same or corresponding parts. Moreover, in each figure, the same code | symbol is attached | subjected to the same element and the overlapping description is abbreviate | omitted.

  With reference to FIGS. 1-3, the oil temperature rising apparatus 1 (henceforth "temperature raising apparatus 1") which concerns on 1st Embodiment is demonstrated. FIG. 1 is a cross-sectional view of a temperature raising device 1 according to the first embodiment. FIG. 2 is a perspective view of the disc spring 10 of the temperature raising device 1 according to the first embodiment. FIG. 3 is a graph showing the elastic deformation characteristics of the disc spring 10 of the temperature raising device 1 according to the first embodiment.

  The temperature raising device 1 raises the temperature of lubricating oil for a portion to be lubricated such as a gear constituting a speed reducer provided in the electric vehicle. The electric vehicle includes an electric motor (not shown) as a drive source. The electric motor functions as an electric motor and a generator. The electric motor is, for example, a three-phase AC type motor generator. The power generated by the electric motor is transmitted to drive wheels (not shown) via the speed reducer 3.

  The reduction gear 3 includes a drive gear 4 and a driven gear 5 that meshes with the drive gear 4. The drive gear 4 is attached to the output shaft of an electric motor, for example. The driven gear 5 is attached to a rotating shaft 6 (for example, a propeller shaft) by spline fitting. The driven gear 5 is slidable in the axial direction of the rotary shaft 6 and is not rotatable relative to the rotary shaft 6. The driven gear 5 is coupled to the drive wheels via, for example, a propeller shaft, a differential gear, a drive shaft, and the like.

  The gears 4 and 5 of the speed reducer 3 are helical gears, and a thrust force is generated when torque is applied. The drive gear 4 generates a thrust force (gear reaction force) in the first direction D1 when the electric motor of the electric vehicle drives the drive wheels (hereinafter referred to as “driving”), and the electric motor is driven by the inertial force. Is driven in reverse (when coasting (hereinafter referred to as “coast running”)), a thrust force is generated in the second direction D2. On the other hand, the driven gear 5 generates a thrust force in the second direction D2 during driving of the electric vehicle, and generates a thrust force in the first direction D1 during coasting.

  One end of the rotary shaft 6 in the axial direction is supported by a bearing 7. The outer race 7a of the bearing 7 is attached to a case 9 that houses the speed reducer 3 and the like. An inner race 7 b of the bearing 7 is attached to the rotating shaft 6. In the bearing 7, an outer race 7 a (corresponding to a non-rotating portion described in the claims) is fixed to the case 9, and an inner race 7 b (corresponding to the rotating portion described in the claims) is a rotating shaft 6. Rotate with. In addition, the edge part of the other side of the axial direction of the rotating shaft 6 is supported by the bearing 8 (refer FIG. 4).

  To-be-lubricated parts such as the speed reducer 3 (the gears 4 and 5) and the bearing 7 accommodated in the case 9 are lubricated by oil. This lubrication is performed, for example, when the driven gear 5 of the speed reducer 3 is immersed in oil, and the oil is picked up and scattered by the rotation of the driven gear 5.

  The temperature raising device 1 is configured between the driven gear 5 and the bearing 7 of the speed reducer 3 and uses the rotation of the driven gear 5. The temperature raising device 1 raises the temperature of the oil by frictional heat by bringing the contact member attached to the driven gear 5 and the non-rotating member into contact with each other when the temperature is low. Do not touch. The temperature raising device 1 includes a disc spring 10 (corresponding to a contact member described in claims), a friction material 11, a shape memory alloy 12 (corresponding to a temperature-sensitive deformation member described in claims), It has.

  The disc spring 10 is a member that is brought into contact with the friction material 11. As shown in FIG. 3, the disc spring 10 is an elastic member that elastically deforms nonlinearly with respect to a load. In FIG. 3, the horizontal axis is the crushing allowance (the amount of deformation in the axial direction of the rotating shaft 6) of the disc spring 10, and the vertical axis is the load received by the disc spring 10.

  The disc spring 10 has a shape in which an annular plate having a hole in the center is formed in a substantially truncated cone shape. The diameter (the diameter on the bearing 7 side) of the minimum portion of the hole 10a at the center of the disc spring 10 is substantially the same as the inner diameter of the outer race 7a of the bearing 7, for example. The substantially frustoconical upper portion 10 b of the disc spring 10 is a portion that contacts the friction material 11. A substantially truncated cone-shaped bottom portion 10c of the disc spring 10 is located on the outer side of the driven gear 5 in the radial direction from the outer race 7a of the bearing 7 on the side portion (one side portion in the axial direction of the rotating shaft 6). To be attached to 5a. Accordingly, the disc spring 10 rotates together with the driven gear 5 (rotating shaft 6). The disc spring 10 is disposed such that the upper portion 10b faces the friction material 11 (the side surface 7c of the outer race 7a of the bearing 7).

  The axial length (the height of the disc spring 10) of the rotating shaft 6 of the disc spring 10 in a state where the disc spring 10 is not elastically deformed is a predetermined portion 5a on the side portion of the driven gear 5 and the bearing 7 when the electric vehicle is cold. This is slightly longer than the distance from the friction material 11 attached to the outer race 7a (the distance in the axial direction of the rotating shaft 6). Therefore, during the cold state, the disc spring 10 is elastically deformed, and the upper portion 10b contacts the friction material 11.

  The friction material 11 is a member that contacts the disc spring 10. The friction material 11 is formed of, for example, the same material as the friction material used in a clutch provided in an automobile. The friction material 11 is attached to the side surface 7 c of the outer race 7 a of the bearing 7 fixed to the case 9.

  The friction material 11 has an annular shape having a predetermined thickness. The inner diameter of the friction material 11 is substantially the same as the inner diameter of the outer race 7a of the bearing 7, for example. The outer diameter of the friction material 11 is substantially the same as the outer diameter of the outer race 7a, for example.

  The shape memory alloy 12 is a member that widens the space between the driven gear 5 and the bearing 7 when the temperature rises. When the shape memory alloy 12 reaches a predetermined temperature or higher, the shape memory alloy 12 returns to its original shape and increases at least in the axial direction of the rotary shaft 6. As the shape memory alloy 12, an alloy having a predetermined temperature (transformation temperature) at which the viscosity of the lubricating oil becomes sufficiently low (for example, 60 to 80 ° C.) is used.

  The shape memory alloy 12 has, for example, a cylindrical shape with a hole in the center. The inner diameter of the shape memory alloy 12 (the diameter of the hole in the central portion) is, for example, substantially the same as the inner diameter of the inner race 7b of the bearing 7. The outer diameter of the shape memory alloy 12 is, for example, substantially the same as the outer diameter of the inner race 7b. One end portion of the shape memory alloy 12 in the axial direction is attached to a predetermined portion (a portion facing the inner race 7 b of the bearing 7) 5 b on the side portion of the driven gear 5. As a result, the shape memory alloy 12 rotates with the rotating shaft 6 (no differential rotation occurs) between the driven gear 5 and the inner race 7b of the bearing 7 so that the other end faces the side surface 7d of the inner race 7b. Placed in. The predetermined part 5b is a part on the inner peripheral side with respect to the part 5a to which the disc spring 10 is attached.

  The axial length of the rotating shaft 6 of the shape memory alloy 12 in a deformed state (before recovery to the original shape) is determined by the predetermined location 5b on the side of the driven gear 5 and the bearing when the electric vehicle is cold. 7 is shorter than the distance from the side surface 7d of the inner race 7b. Therefore, the shape memory alloy 12 does not come into contact with the inner race 7b in the cold state. On the other hand, the axial length of the rotating shaft 6 of the shape memory alloy 120 restored to its original shape is larger than the distance between the predetermined portion 5b on the side of the driven gear 5 and the inner race 7b when the electric vehicle is cold. become longer. Therefore, when the temperature of the shape memory alloy 12 becomes equal to or higher than a predetermined temperature, the shape memory alloy 12 expands the space between the driven gear 5 and the bearing 7 by the restoring force.

In particular, in the temperature raising device 1, the driven gear 5 and the bearing 7 are used by utilizing an expansion difference accompanying a temperature increase according to a difference between the linear expansion coefficient (linear expansion coefficient) of the case 9 and the linear expansion coefficient of the rotating shaft 6. Widen the gap. For example, when the rotating shaft 6 is made of iron and the case 9 is made of aluminum, the linear expansion coefficient of the rotating shaft 6 is 12.1 (10 ⁻⁶ / K), and the linear expansion coefficient of the case 9 is 23 (10 ^{− 6} / K).

  That is, since the linear expansion coefficient of the case 9 is larger than the linear expansion coefficient of the rotating shaft 6, when the temperature rises due to warming up, the case 9 expands more than the rotating shaft 6 according to the difference in linear expansion coefficient, and the rotating shaft 6 The case 9 extends beyond the rotary shaft 6 in the axial direction. Since the bearing 7 is attached to the case 9 and the driven gear 5 is attached to the rotating shaft 6, when the case 9 extends beyond the rotating shaft 6, the bearing 7 moves along the case 9 in the axial direction with respect to the driven gear 5. The space between the bearing 7 and the driven gear 5 is widened.

  With reference to FIG. 4 and FIG. 5, the operation of the temperature raising device 1 will be described. FIG. 4 is a diagram schematically illustrating a state during temperature rising by the temperature increasing device 1 according to the first embodiment. FIG. 5 is a diagram schematically showing a state after the temperature rise by the temperature raising device 1 according to the first embodiment.

  First, with reference to FIG. 4, the operation during the temperature rise (warming up) by the temperature raising device 1 will be described. For example, since the temperature is low when the electric vehicle is cold, the shape memory alloy 12 is in a deformed state (a contracted state) and is not in contact with the inner race 7 b of the bearing 7. Therefore, the space between the bearing 7 and the driven gear 5 is not widened by the shape memory alloy 12. Further, since the temperature is low, the difference in expansion between the case 9 and the rotating shaft 6 corresponding to the difference in linear expansion coefficient between the case 9 and the rotating shaft 6 is small. Therefore, the disc spring 10 attached to the driven gear 5 is in contact with the friction material 11 attached to the outer race 7 a of the bearing 7.

  In particular, during coasting of an electric vehicle, a unidirectional torque is applied to the driven gear 5, and a thrust force is generated in the driven gear 5 in the direction D1 on the bearing 7 side. Therefore, the disc spring 10 in contact with the friction material 11 receives a load due to a thrust force. Thereby, the disc spring 10 is pressed against the friction material 11 by this load and deforms. When the electric vehicle is driven, torque is applied to the driven gear 5 in the other direction, and a thrust force is generated in the driven gear 5 in the direction D2 on the bearing 8 side. As a result, the driven gear 5 slides toward the bearing 8, and the disc spring 10 does not contact the friction material 11. Therefore, the drive torque generated by the electric motor is not lost.

  The disc spring 10 rotates with the rotation of the driven gear 5 (rotating shaft 6). On the other hand, since the friction material 11 is provided in the outer race 7a attached to the case 9, it does not rotate. Therefore, differential rotation occurs between the disc spring 10 and the friction material 11 that are in contact with each other, and frictional heat is generated. The generated heat raises the temperature of the lubricating oil. Thereby, the viscosity of oil becomes low, for example, the stirring resistance at the time of the driven gear 5 scooping up oil reduces.

  Next, with reference to FIG. 5, the operation at the end of the temperature increase by the temperature increasing device 1 (at the end of warm-up) will be described. When each temperature of the case 9 and the rotating shaft 6 rises due to the heat generated by the friction described above, the case 9 having a larger linear expansion coefficient expands more than the rotating shaft 6. As the temperature rises, the difference in expansion between the case 9 and the rotating shaft 6 (difference in the axial direction of the rotating shaft 6) increases. Since the bearing 7 is attached to the case 9 and the driven gear 5 is attached to the rotating shaft 6, the space between the bearing 7 and the driven gear 5 is expanded according to the difference in expansion between the case 9 and the rotating shaft 6.

  Further, the temperature of the shape memory alloy 12 rises due to the heat generated by the friction described above. When the temperature of the shape memory alloy 12 becomes equal to or higher than a predetermined temperature (transformation temperature), the shape memory alloy 12 returns (expands) to its original shape. As a result, the axial length of the rotational axis 6 of the shape memory alloy 12 is increased, and the shape memory alloy 12 comes into contact with the side surface 7d of the inner race 7b of the bearing 7 so that the gap between the driven gear 5 and the bearing 7 is increased. spread. At this time, the restoring force of the shape memory alloy 12 exceeds the thrust force of the driven gear 5, and the driven gear 5 is slid to the bearing 8 side. In addition to the action due to the difference in expansion between the case 9 and the rotating shaft 6 described above, the action of the shape memory alloy 12 ensures a widening between the bearing 7 and the driven gear 5.

  Since the space between the bearing 7 and the driven gear 5 is widened, the distance between the predetermined portion 5a on the side of the driven gear 5 and the friction material 11 (the outer race 7a of the bearing 7) is increased. When this interval becomes larger than the axial length of the rotating shaft 6 of the disc spring 10 (the height of the disc spring 10), the disc spring 10 does not contact the friction material 11. Thereby, the temperature increase of the oil by the temperature increasing device 1 is completed.

  During coasting of the electric vehicle, when the temperature of the oil is raised by the temperature raising device 1, the kinetic energy due to the power from the drive wheels is converted into the heat energy due to the friction between the disc spring 10 and the friction material 11, and the oil Used for heating.

An example of the expansion difference accompanying the temperature rise of case 9 and rotating shaft 6 mentioned above is shown. The elongation of the object (axial extension of the rotating shaft 6) is ΔL (mm), the linear expansion coefficient is α (10 ⁻⁶ / K), the length of the object is L (mm), and the temperature rise is ΔT In the case of (K), ΔL = α × L × ΔT. In the example shown here, the temperature rise ΔT by the temperature raising device 1 is 50 (K), the length L1 (see FIG. 4) of the rotating shaft 6 in the cold state is 250 mm, and the length L2 of the case 9 (FIG. 4) is 300 mm. In this case, after the temperature rises, the elongation ΔL of the rotating shaft 6 is about 0.15 (mm). On the other hand, the elongation ΔL of the case 9 is about 0.34 (mm). Accordingly, the difference in expansion (expansion difference) between the case 9 and the rotating shaft 6 is about 0.19 (mm).

  In the case of this example, the axial length of the rotating shaft 6 of the disc spring 10 that is not elastically deformed is, for example, the distance between the predetermined portion 5a on the side of the driven gear 5 and the friction material 11 in the cold state. More than a predetermined length (any length between 0.05 (mm) and 0.19 (mm)). By setting in this way, the disc spring 10 can be brought into contact with the friction material 11 in an elastically deformed state in the cold state, and when the difference in expansion between the case 9 and the rotary shaft 6 increases due to a rise in temperature, the disc spring 10 Can be shifted to a state where the friction material 11 is not brought into contact with the friction material 11.

  According to the temperature raising device 1 according to the first embodiment, the temperature rise of the oil that lubricates the lubricated part can be promoted by bringing the disc spring 10 into contact with the friction material 11 when the temperature is low and coasting. . Thereby, in an electric vehicle, the temperature rise of oil is accelerated, and friction loss due to high viscosity oil can be reduced quickly.

  According to the temperature raising device 1 according to the first embodiment, the expansion of the case 9 and the rotating shaft 6 due to the temperature rise according to the elastic characteristics of the disc spring 10 and the difference in linear expansion coefficient between the case 9 and the rotating shaft 6. By utilizing the difference, the disc spring 10 can be brought into contact with the friction material 11 when the temperature is low, and the disc spring 10 can be prevented from coming into contact with the friction material 11 when the temperature is high. In particular, the axial direction of the contact member (disc spring 10) that is brought into a non-contact state with respect to the friction material 11 by using a disc spring 10 that elastically deforms nonlinearly with respect to a load (thrust force) as a contact member. Length adjustment (clearance adjustment between the friction material 11 and the contact member) can be easily performed.

  According to the temperature raising device 1 according to the first embodiment, by providing the shape memory alloy 12 between the driven gear 5 that rotates together with the rotating shaft 6 and the inner race 7b of the bearing 7, the shape memory is obtained when the temperature exceeds a predetermined temperature. By returning the alloy 12 to its original shape, the disc spring 10 can be reliably prevented from coming into contact with the friction material 11.

  According to the temperature raising device 1 according to the first embodiment, by providing the friction material 11 at a position where the disc spring 10 is brought into contact, heat can be efficiently generated by friction between the disc spring 10 and the friction material 11. The temperature rise of the oil can be promoted.

  According to the temperature raising device 1 according to the first embodiment, when coasting in an electric vehicle, if the temperature is low, the kinetic energy used for normal regeneration can be utilized to promote the temperature rise of the oil. Thus, kinetic energy can be recovered as electric energy. Note that when the electric vehicle is driven, the temperature raising device 1 is configured such that the disc spring 10 is not brought into contact with the friction material 11, so that the driving torque generated by the electric motor is not lost.

  As described above, the temperature raising device 1 uses the elastic characteristic of the disc spring 10 and the difference in expansion between the case 9 and the rotating shaft 6 according to the difference in linear expansion coefficient between the case 9 and the rotating shaft 6. Thus, since the disc spring 10 can be brought into a non-contact state from being in contact with the friction material 11, the shape memory alloy 12 may not be provided.

  With reference to FIG. 6 and FIG. 7, the temperature rising apparatus 2 which concerns on 2nd Embodiment is demonstrated. FIG. 6 is a cross-sectional view of the temperature raising device 2 according to the second embodiment. FIG. 7 is a perspective view of the contact member 20 of the temperature raising device 2 according to the second embodiment.

  The temperature raising device 2 is different from the temperature raising device 1 according to the first embodiment in that a contact member 20 is used instead of the disc spring 10. The temperature raising device 2 includes a contact member 20, a friction material 11, and a shape memory alloy 12.

  The contact member 20 is a member that is brought into contact with the friction material 11. The contact member 20 is made of a metal such as iron, for example. The contact member 20 has, for example, a cylindrical shape with a hole in the center. The inner diameter of the contact member 20 (the diameter of the central hole 20a) is, for example, substantially the same as the inner diameter of the outer race 7a of the bearing 7. The outer diameter of the contact member 20 is, for example, substantially the same as the outer diameter of the outer race 7a. One end of the contact member 20 is attached to a predetermined portion (a portion facing the outer race 7 a of the bearing 7) 5 c on the side portion of the driven gear 5.

  The axial length (the height of the contact member 20) of the rotating shaft 6 of the contact member 20 is attached to a predetermined portion 5c on the side of the driven gear 5 and the outer race 7a of the bearing 7 when the electric vehicle is cold. The distance to the friction material 11 (the distance in the axial direction of the rotating shaft 6) is substantially the same as or slightly shorter.

  Next, the operation of the temperature raising device 2 will be described. Here, differences from the description of the operation of the temperature raising device 1 according to the first embodiment will be described. For example, since the temperature is low when the electric vehicle is cold, the shape memory alloy 12 is in a deformed state and is not in contact with the inner race 7 b of the bearing 7. Therefore, the space between the bearing 7 and the driven gear 5 is not widened by the shape memory alloy 12. In particular, during coasting of the electric vehicle, a thrust force is generated in the driven gear 5 in the direction D1 on the bearing 7 side. Therefore, in the temperature raising device 2, the contact member 20 is pressed against the friction material 11 by the thrust force. A differential rotation occurs between the contact member 20 and the friction material 11 in contact with each other, and frictional heat is generated. The generated heat raises the temperature of the lubricating oil. At this time, the contact member 20 does not elastically deform according to the thrust force like the disc spring 10 according to the first embodiment.

  When the temperature rises, in the temperature raising device 2, the shape memory alloy 12 having a predetermined temperature or higher returns to its original shape and expands. The expanded shape memory alloy 12 expands the space between the bearing 7 and the driven gear 5, and the contact member 20 does not contact the friction material 11. In addition, since the contact member 20 does not elastically deform according to the thrust force unlike the disc spring 10 according to the first embodiment, the axial length of the contact member 20 that changes from the contact state to the non-contact state with respect to the friction material 11. Adjustment (clearance adjustment between the friction material 11 and the contact member 20) cannot be easily performed. Therefore, in the temperature raising device 2, the shape memory alloy 12 is used without using the difference in expansion between the case 9 and the rotating shaft 6 according to the difference in linear expansion coefficient between the case 9 and the rotating shaft 6 as in the first embodiment. This is a configuration in which the disc spring 10 and the friction material 11 are shifted from the contact state to the non-contact state only by the action of.

  As described above, since the temperature raising device 2 does not use the difference in expansion between the case 9 and the rotating shaft 6, the linear expansion coefficient of the case 9 is not larger than the linear expansion coefficient of the rotating shaft 6 in the electric vehicle according to the second embodiment. For example, the rotating shaft 6 and the case 9 may be formed of the same material (a material having the same linear expansion coefficient).

  According to the temperature raising device 2 according to the second embodiment, the temperature rise of the oil that lubricates the lubricated part can be promoted by bringing the contact member 20 into contact with the friction material 11 when the temperature is low and coasting. . In particular, according to the temperature raising device 2 according to the second embodiment, when the shape memory alloy 12 is also provided between the driven gear 5 that rotates together with the rotating shaft 6 and the inner race 7b of the bearing 7, the temperature rises to a predetermined temperature or more. By returning the shape memory alloy 12 to its original shape, the contact member 20 can be prevented from contacting the friction material 11.

  Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and various modifications can be made. For example, although the temperature raising devices 1 and 2 are applied to an electric vehicle in the above embodiment, the present invention can also be applied to a vehicle including an engine as a drive source. Moreover, if it requires the temperature rise of oil, it can also apply other than a motor vehicle.

  In the above embodiment, the temperature raising devices 1 and 2 are provided on the driven gear 5 side of the speed reducer 3. However, the temperature raising devices 1 and 2 may be provided on the drive gear 4 side. It is good. Moreover, it is good also as a structure provided in gears other than a reduction gear.

  In the above embodiment, the present invention is applied to the helical gear (driven gear 5). However, any gear other than the helical gear can be used as long as it generates a thrust force in the axial direction.

  Although the example which made the shape memory alloy 12 cylindrical shape was shown in the said embodiment, it is good also as another shape. For example, in the case of a coil spring shape, one coil spring-shaped shape memory alloy having a diameter larger than that of the rotating shaft 6 is arranged at the same position as the shape memory alloy 12, or a plurality of coils having a small diameter Spring-like shape memory alloys are arranged at predetermined intervals in the circumferential direction.

  In the above embodiment, the friction material 11 is provided on the outer race 7a (non-rotating portion) of the bearing 7 and the contact members 10 and 20 are brought into contact with the friction material 11 to generate frictional heat. It is good also as a structure which provides the other member consisting of resin etc., or is good also as a structure which makes the contact members 10 and 20 contact the outer race 7a directly, without providing a friction material. Moreover, it is good also as a structure which makes the contact members 10 and 20 contact the predetermined location (non-rotating part) of the case 9 directly.

  In the above embodiment, the shape memory alloy 12 is disposed between the side portion of the driven gear 5 and the side surface 7d of the inner race 7b (rotating portion) of the bearing 7, and the shape memory alloy 12 that has returned to its original shape is disposed on the inner race 7b. Although it was set as the structure made to contact 7 d of side surfaces, you may arrange | position the shape memory alloy 12 between other rotating parts, for example, form a convex part (rotating part) along the circumferential direction in the rotating shaft 6, It is good also as a structure which arrange | positions the shape memory alloy 12 between the side part of the driven gear 5, and its convex part, and makes the shape memory alloy 12 which returned to the original shape contact a convex part.

  In the above embodiment, the present invention is applied to the case where the temperature of the lubricating oil is raised by the temperature raising devices 1 and 2, but the present invention can also be applied to the case of raising the temperature of other oils used for hydraulic control or the like.

  In the above embodiment, the contact member (the disc spring 10 and the contact member 20) is provided on one side of the driven gear 5 in the axial direction of the rotating shaft 6. However, the driven gear 5 has a thrust force in the direction D1 on the bearing 7 side. As long as this occurs, the contact member may be provided on the other side portion of the driven gear 5 in the axial direction of the rotating shaft 6 as long as it contacts the non-rotating portion in the case 9.

  In the first embodiment, the disc spring 10 is used as the contact member (elastic member), but other elastic members may be used. For example, when a coil spring is used as the elastic member, a plurality of coil springs are arranged at predetermined intervals in the circumferential direction.

  In the second embodiment, the contact member 20 is a separate member from the driven gear 5, but a convex portion corresponding to the contact member 20 may be integrally formed on the side portion of the driven gear 5.

  Moreover, as shown in FIG. 8, it is good also as the oil temperature rising apparatus 3 which is not provided with a shape memory alloy and a friction material. In the case of this oil temperature raising device 3, by using the difference in expansion between the case 9 and the rotating shaft 6 due to the temperature rise corresponding to the difference in linear expansion coefficient between the case 9 and the rotating shaft 6, the dish is used when the temperature is low. The spring 10 can be brought into contact with the outer race 7a of the bearing 7, and when the temperature becomes high, the disc spring 10 can be prevented from coming into contact with the outer race 7a. Further, heat can be generated by the disc spring 10 rotating together with the driven gear 5 coming into contact with the outer race 7a.

1, 2, 3 Temperature raising device 3 Reducer 5 Driven gear 6 Rotating shaft 7, 8 Bearing 7a Outer race 7b Inner race 9 Case 10 Belleville spring 11 Friction material 12 Shape memory alloy 20 Contact member

Claims (11)

A gear provided in a rotating shaft that is housed in a case and supported by a bearing attached to the case;
Provided on at least one side of the rotating shaft in the axial direction of the gear, and when the distance between the one side of the gear and the non-rotating part in the case is equal to or less than a predetermined distance A contact member that contacts the rotating part;
With
The gear is a gear that generates a thrust force when torque is applied,
The thrust force of the gear is generated in the direction of the non-rotating part when torque is applied to the gear in one direction,
The oil temperature increasing device, wherein the case has a linear expansion coefficient larger than that of the rotating shaft, and expands more than the rotating shaft at least in the axial direction of the rotating shaft as the temperature rises. A temperature-sensitive deformation member that is provided between the one side portion of the gear and a rotating portion that rotates along with the rotating shaft, and that increases at least in the axial direction of the rotating shaft when the temperature exceeds a predetermined temperature;
When the temperature sensitive deformation member becomes larger in the axial direction of the rotating shaft, the temperature sensitive deformation member causes the gap between the one side portion of the gear and the non-rotating portion in the case to be the predetermined distance. The oil temperature raising device according to claim 1, wherein the oil temperature raising device is larger. A gear provided in a rotating shaft that is housed in a case and supported by a bearing attached to the case;
Provided on at least one side of the rotating shaft in the axial direction of the gear, and when the distance between the one side of the gear and the non-rotating part in the case is equal to or less than a predetermined distance A contact member that contacts the rotating part;
A temperature-sensitive deformation member that is provided between the one side of the gear and a rotating portion that rotates with the rotating shaft, and that becomes larger at least in the axial direction of the rotating shaft when the temperature exceeds a predetermined temperature;
With
The gear is a gear that generates a thrust force when torque is applied,
The thrust force of the gear is generated in the direction of the non-rotating part when torque is applied to the gear in one direction,
When the temperature sensitive deformation member becomes larger in the axial direction of the rotating shaft, the temperature sensitive deformation member causes the gap between the one side portion of the gear and the non-rotating portion in the case to be the predetermined distance. Oil temperature increasing device characterized by being larger than the above.   4. The oil temperature raising apparatus according to claim 1, wherein the contact member is an elastic member. 5.   The oil heating device according to claim 4, wherein the contact member is a disc spring. The oil temperature raising device is provided in a vehicle,
The oil temperature raising device according to any one of claims 1 to 5, wherein the thrust force of the gear is generated in a direction toward the non-rotating portion during coasting of the vehicle. The oil temperature rising device according to claim 6, wherein the vehicle is an electric vehicle.
The non-rotating part is provided with a friction material,
The oil temperature rising device according to any one of claims 1 to 7, wherein the contact member is in contact with the friction material provided in the non-rotating portion.   The oil non-rotating device according to any one of claims 1 to 8, wherein the non-rotating portion is an outer race of the bearing.   The oil temperature rising device according to any one of claims 2 to 9, wherein the rotating portion is an inner race of the bearing.   The oil temperature raising device according to any one of claims 2 to 10, wherein the temperature-sensitive deformation member is a shape memory alloy.

Images