JP2015100270A - Oscillatory wave motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an oscillatory wave motor which is adaptive to environment in which heat countermeasures are taken for use of the oscillatory wave motor, and can suppress differences in temperature distribution among components constituting the oscillatory wave motor.SOLUTION: There is provided the oscillatory wave motor including an oscillator having an elastic body to which an electromechanical conversion element is joined and a moving body coming into contact with the oscillator. The oscillator and moving body are pressed by a pressing member to form a plurality of contact surfaces, the moving body is frictionally driven by movements generated on the plurality of contact surfaces by application of an electric signal to the electromechanical energy conversion element, and a common output shaft outputs a plurality of driving powers generated by the plurality of contact surfaces. The oscillatory wave motor is configured to adjust heating value generated by the frictional drive differently among the plurality of contact surfaces.

Description

  The present invention relates to a so-called vibration wave motor that frictionally drives a moving body in contact with a vibrator, and relates to a heat countermeasure technique for the vibration wave motor.

  The vibration wave motor has been put into practical use as an autofocus driving motor in, for example, a photographing lens of a single-lens reflex camera because of its features such as low speed and large torque. However, in recent years, higher output has been demanded.

  In response to such a problem, Patent Document 1 and Patent Document 2 propose a vibration wave motor that obtains a large output by combining a plurality of vibrators and a plurality of moving bodies.

JP 2001-016875 A JP 2003-047263 A

  However, in the above-described conventional technology, depending on the environment in which heat countermeasures are performed when using the vibration wave motor, the temperature distribution difference between the components of the vibration wave motor becomes large, leading to a decrease in durability of the vibration wave motor. There was a thing.

  These will be described by taking, as an example, a vibration wave motor that includes two vibrators and two moving bodies, and in which the vibrator and the moving bodies form two contact surfaces, as in Patent Document 1 and Patent Document 2.

  In such a vibration wave motor, the environment where the two contact surfaces are placed is not necessarily the same.

  It may be difficult to apply a cooling fan, or heat may be trapped, resulting in local deterioration of heat dissipation.

  In such a case, the temperature of the component near the contact surface placed on the disadvantageous side of heat dissipation is abnormally high enough to degrade its function. This abnormal temperature increase affects the performance of the vibration wave motor and causes a decrease in durability.

  In view of the above problems, the present invention can suppress a difference in temperature distribution between components of a vibration wave motor in response to an environment in which heat countermeasures are performed when the vibration wave motor is used. An object of the present invention is to provide a vibration wave motor capable of suppressing a decrease in durability.

The vibration wave motor of the present invention includes a vibrator having an elastic body to which an electro-mechanical energy conversion element is joined, and a moving body in contact with the vibrator, and the vibrator and the moving body are provided by a pressure member. Pressurized to form multiple contact surfaces,
Vibration that frictionally drives the movable body by motion generated on the plurality of contact surfaces by applying an electric signal to the electro-mechanical energy conversion element, and outputs a plurality of driving forces by the plurality of contact surfaces by a common output shaft. A wave motor,
The heat generation amount generated by the friction drive is configured to be adjustable so as to be different between the plurality of contact surfaces.

  According to the present invention, it is possible to suppress the temperature distribution difference among the components of the vibration wave motor in response to the environment in which heat countermeasures are performed when using the vibration wave motor, and to reduce durability due to local abnormal temperature rise Therefore, it is possible to realize a vibration wave motor capable of suppressing the above.

Sectional drawing explaining the structure of the vibration wave motor in Example 1 of this invention. Sectional drawing explaining the structure of the vibration wave motor in the modification 1 of Example 1 of this invention. Sectional drawing explaining the structure of the vibration wave motor in the modification 2 of Example 1 of this invention. Sectional drawing explaining the structure of the vibration wave motor in the modification 3 of Example 1 of this invention. Sectional drawing explaining the structure of the vibration wave motor in the modification 4 of Example 1 of this invention. Sectional drawing explaining the structure of the vibration wave motor in the modification 5 of Example 1 of this invention. Sectional drawing explaining the structure of the vibration wave motor in Example 2 of this invention. Sectional drawing explaining the structure of the vibration wave motor in the modification 4 of Example 2 of this invention. Sectional drawing explaining the structure of the vibration wave motor in the modification 5 of Example 2 of this invention.

  The mode for carrying out the present invention will be described with reference to the following examples.

[Example 1]
As a first embodiment, a configuration example of a vibration wave motor to which the present invention is applied will be described. A vibrator having an elastic body to which the electro-mechanical energy conversion element of this embodiment is joined, and a moving body that contacts the vibrator, and the vibrator and the moving body are pressurized by a pressure member. A plurality of contact surfaces are formed.

  Then, the movable body is frictionally driven by the plurality of contact surfaces by the elliptical motion generated on the plurality of contact surfaces by applying an electric signal to the electro-mechanical energy conversion element, and a plurality of driving forces by the plurality of contact surfaces are shared. Output by the output shaft.

  Specifically, as shown in FIG. 1, the vibration wave motor of the present embodiment includes a first component group 100a and a second component group 100b, a vibrator fixing member 109, and an output shaft 201. ing.

  The first and second parts groups 100a and 100b include vibrators 101a and 101b, moving bodies 104a and 104b, pressure members 107a and 107b, pressure spring fixing members 108a and 108b, cases 110a and 110b, bearings 111a, 111b.

  The first component group 100a and the second component group 100b have a symmetrical relationship with the vibrator fixing member 109 interposed therebetween.

  First, the first component group 100a will be described.

  The vibrator 101a is formed in an annular shape by an elastic body 102a made of metal to which a piezoelectric element 103a is bonded. The piezoelectric element 103a is an electro-mechanical energy conversion element that converts an electrical quantity into a mechanical quantity. The vibrator 101 a is fixed to the vibrator fixing member 109.

  A case 110 a including a bearing 111 a is attached to the vibrator fixing member 109.

  The vibrator fixing member 109 and the case 110a surround the vibrator 101a, the moving body 104a, the pressing member 107a, and the pressing spring fixing member 108a. The case 110a is provided with a vent (not shown) for improving heat dissipation.

  The moving body 104a is formed in an annular shape by a vibration damping member 105a and a friction member 106a each made of metal.

  The friction member 106a has an L-shaped cross section. The tip of the friction member 106a of the moving body 104a is in contact with the vibrator 101a and forms a first contact surface.

  The first contact surface is pressurized by a pressure member 107a that is a leaf spring.

  The pressure member 107a is fixed to the pressure spring fixing member 108a. The pressure spring fixing member 108 a is fixed to the output shaft 201.

  Next, the second component group will be described.

  The second component group 100b is symmetric with respect to the first component group 100a and the vibrator fixing member 109. The second component group includes the vibrator 101b, the moving body 104b, the pressure member 107b, the pressure spring fixing member 108b, the case 110b, and the bearing 111b, and has the same shape as the first component group 100a.

  The second component group 100b is fixed to the vibrator fixing member 109 and the output shaft 201 that are common to the first component group 100a. The case 110b is provided with a vent (not shown) for improving heat dissipation.

  Here, a method for adjusting the pressurization of the two contact surfaces of the vibration wave motor will be described.

  The output shaft 201 of the vibration wave motor is located where the applied pressures of the pressure members 107a and 107b are balanced when no external force is applied.

  The vibrator fixing member 109 is supported there, and an external force in the direction of the arrow shown in FIG. 1 is applied to the output shaft 201 to displace the output shaft 201 from the second case 110b side to the first case 110a side.

  Then, the bending of the second pressure member 107b increases and the bending of the first pressure member 107a decreases.

  In this state, the output shaft 201 and the first bearing 111a are fixed by the pressure adjusting member 202 outside the first case 110a. The pressure adjusting member 202 may be an E-ring.

  Thereby, the pressing force of the first contact surface in the first component group 100a is smaller than the pressing force of the second contact surface in the second component group 100b, and is different between these contact surfaces. Can do.

  The amount of deviation of the output shaft 201 up to the fixed position, that is, the position where the pressure adjusting member 202 is attached to the output shaft 201 is determined by the difference between the applied pressures of the first and second contact surfaces to be set, the pressure member 107a, It is determined from the spring rigidity of 107b.

  The driving principle of such a vibration wave motor will be described.

  By applying an AC signal to the piezoelectric elements 103a and 103b of the vibrators 101a and 101b, elliptical motion is generated on the contact surfaces of the vibrators 101a and 101b with the moving bodies 104a and 104b, and the moving bodies 104a and 104b are driven by friction. Configured to do.

  The moving bodies 104a and 104b rotate in the same direction, and the rotation output is transmitted to the common output shaft 201 via the pressure members 107a and 107b and the pressure spring fixing members 108a and 108b.

  The effect of the present embodiment described above will be described.

  When the vibration wave motor is driven by friction, the frictional force on the first contact surface is smaller than that on the second contact surface due to the difference in the applied pressure between the two contact surfaces. Get smaller.

  Thereby, compared with the 2nd components group 100b, the temperature rise by the self-heating of the 1st components group 100a becomes small.

  When the vibration wave motor having such a form is attached to the apparatus housing 203 as shown in FIG. 1, it is difficult to implement a heat countermeasure such as a cooling fan on the side surrounded by the apparatus housing 203.

  Therefore, by disposing the first component group 100a having a small temperature rise due to self-heating at a disadvantageous position for heat dissipation, and disposing the second component group 100b having a large temperature rise due to self-heating at a position advantageous for heat dissipation, A difference in temperature distribution of the entire vibration wave motor can be suppressed.

  As described above, by configuring the heat generation amount generated by the friction drive so as to be different between the plurality of contact surfaces, the durability deterioration due to the local abnormal temperature rise of the components of the vibration wave motor is improved. A vibration wave motor can be realized.

  A modification of the present embodiment shown in FIG. 1 will be described.

  Modification 1 will be described.

  While the vibration wave motor of this embodiment is being driven, it is possible to respond to changes in the surrounding environment at any time by actively changing the applied pressures of the two contact surfaces as needed. Specifically, as shown in FIG. 2, by using an output shaft 201 provided with a pressure adjusting piezoelectric element (pressure adjusting member) 205 and energizing the piezoelectric element 205, the axial position of the output shaft 201 is set. A method of changing the pressure applied to the two contact surfaces at the same time is conceivable.

  More specifically, a temperature detection sensor that detects the temperature of the motor during friction driving and / or the temperature of the surrounding environment is configured.

  A configuration in which the pressure adjusting piezoelectric element 205 is operated based on the detection result of the temperature detection sensor to displace the output shaft 201 in the axial direction can be employed. In this modification, a piezoelectric element is used as the axial displacement means for the output shaft, but the present invention is not limited to this. As other means, a magnetostrictive element, a pneumatic actuator, etc. can be considered.

  Modification 2 will be described.

  In the present embodiment, the method using the pressure adjusting member 202 has been described as the method for fixing the output shaft 201 of the vibration wave motor.

  As a modification, as shown in FIG. 3, after the vibration wave motor is attached to the apparatus housing 203, when the driven body 204 and the output shaft 201 are connected, the position of the output shaft 201 is changed to the first and second positions. A method of fixing by shifting from a position where the applied pressure of the contact surface becomes equal can be considered.

  Modification 3 will be described.

  In the present embodiment, the example in which the pressurizing forces of the two contact surfaces are simultaneously adjusted by the fixed position of the output shaft 201 has been described. As a modification, as shown in FIG. 4, the output shaft 201 is restrained in the axial direction between the first and second component groups 100a and 100b, and the pressure applied to the first and second contact surfaces is independently adjusted. A vibration wave motor can be considered.

  Modification 4 will be described. In the present embodiment, the example of the vibration wave motor including the two vibrators 101a and 101b and the two moving bodies 104a and 104b has been described. However, the present invention is not limited to this configuration. Any configuration may be used as long as the vibration wave motors face each other.

  For example, as a modification, a vibration wave motor including one vibrator 101 as shown in FIG. 5 and two moving bodies 104a and 104b, two vibrators 101a and 101b as shown in FIG. A vibration wave motor including the moving body 104 can be given. In the vibration wave motor shown in FIG. 6, the pressure members 107a and 107b are integrated with the elastic bodies 102a and 102b.

  Modification 5 will be described.

  In this embodiment, an example of a rotary vibration wave motor has been described. However, the present invention is not limited to this configuration, and a linear motion type motor may be used as long as the vibration wave motor has a plurality of contact surfaces and a plurality of pressurizing directions are opposed to each other. A vibration wave motor may be used.

  Modification 6 will be described.

  In the present embodiment, the example of the vibration wave motor that drives the moving body by the elliptical movement of the contact surface of the vibrator has been described, but the configuration is not limited thereto. For example, a vibration wave motor that drives the moving body by reciprocating the contact surface of the vibrator and pushing the moving body (for example, a motion that pushes the moving body multiple times in one direction by an expansion / contraction motion) may be used.

  Modification 7 will be described.

  In the present embodiment, the method of adjusting the applied pressure has been described as a method of adjusting the heat generation amount of the plurality of contact surfaces during friction driving, but is not limited to this method. For example, the amount of heat generated by the plurality of contact surfaces can be adjusted by making the amount of sliding and the sliding speed of the contact surfaces different during friction driving differ between the plurality of contact surfaces.

[Example 2]
As a second embodiment, a configuration example of a vibration wave motor having a different form from the first embodiment will be described. In the first embodiment, the vibration wave motor in which the directions of pressurization on the plurality of contact surfaces face each other, including the modification, has been described. In Example 2, a case where the directions of pressurization on the plurality of contact surfaces are the same will be described.

  As shown in FIG. 7, the vibration wave motor according to the present embodiment is formed by overlapping a first component group and a second component group in parallel.

  The vibration wave motor forms two contact surfaces, and the pressing directions of the contact surfaces by the pressure members 107a and 107b are the same.

  A method for adjusting the pressure applied to the two contact surfaces of the vibration wave motor will be described.

  In the vibration wave motor of this embodiment, as a method of making the applied pressures of the two contact surfaces different, as in the first embodiment, an external force is applied to the output shaft 201 to displace it, and the position of the output shaft 201 is simply fixed. It is insufficient.

  Furthermore, it is necessary to use the first and second pressure members 107a and 107b having different spring rigidity.

  Thereby, an external force is given to the output shaft 201, and the applied pressure on the first and second contact surfaces can be made different by displacing in the axial direction.

  A case where the pressure applied to the first and second contact surfaces is equal in a state where no external force is applied to the output shaft 201 will be described.

  In order to adjust the pressurization of the two contact surfaces of the vibration wave motor, an external force is applied to the output shaft 201 to displace it from the second case 110b side to the first case 110a side.

  Then, the amount of bending of both the first and second pressure members 107a and 107b increases, but a difference occurs in the applied pressure between the two contact surfaces due to the difference in spring rigidity.

  The pressure applied to the contact surface pressed by the pressure member having a large spring rigidity is increased.

  At this position, the pressure adjusting member 202 is fixed to the outside of the first case 110a of the output shaft 201. The pressure adjusting member 202 may be an E-ring.

  The fixed position of the output shaft 201, that is, the position where the pressure adjusting member 202 is attached depends on the difference between the applied pressures of the first and second contact surfaces to be set and the spring rigidity of the first and second pressure springs. Determined.

  The effects of the present embodiment will be described.

  A case where the spring rigidity of the first pressure member 107a is smaller than the spring rigidity of the second pressure member 107b will be described.

  The pressure applied to the first contact surface is smaller than the pressure applied to the second contact surface. When the vibration wave motor is driven by friction, the frictional force on the first contact surface having a lower pressure is smaller than that of the second contact surface, and the amount of generated heat is reduced. That is, the temperature rise of the first component group 100a is smaller than that of the second component group 100b.

  When the vibration wave motor having such a form is attached to the apparatus housing 203 as shown in FIG. 1, it is difficult to implement a heat countermeasure such as a cooling fan on the side surrounded by the apparatus housing 203.

  Therefore, by disposing the first component group 100a having a small temperature rise due to self-heating at a disadvantageous position for heat dissipation, and disposing the second component group 100b having a large temperature rise due to self-heating at a position advantageous for heat dissipation, A difference in temperature distribution of the entire vibration wave motor can be suppressed.

  Thereby, the vibration wave motor which improved the durability fall by the local abnormal temperature rise of the structural member of a vibration wave motor is realizable.

  A modification of this embodiment shown in FIG. 7 will be described.

  Modification 1 will be described.

  By actively changing the pressure on the contact surface as needed during the driving of the vibration wave motor of this embodiment, the surrounding environment can cope with the change during the driving of the vibration wave motor.

  Specifically, the pressure adjusting piezoelectric element 205 is sandwiched between the output shaft 201 and the driven body 204, and the piezoelectric element 205 is energized to change the axial position of the output shaft 201, thereby two contact surfaces. It is conceivable to change the pressure of the two at the same time.

  More specifically, a temperature detection sensor that detects the temperature due to heat generated on the plurality of contact surfaces by friction driving and / or the temperature of the surrounding environment is configured.

  A configuration in which the pressure adjusting piezoelectric element 205 is operated based on the detection result of the temperature detection sensor to displace the output shaft 201 in the axial direction can be employed. In this modification, a piezoelectric element is used as the axial displacement means for the output shaft, but the present invention is not limited to this. As other means, a magnetostrictive element, a pneumatic actuator, etc. can be considered.

  Modification 2 will be described.

  In the present embodiment, the method using the pressure adjusting member 202 has been described as the method for fixing the output shaft 201 of the vibration wave motor.

  As a modification, when the driven body 204 and the output shaft 201 are fixed after the vibration wave motor is attached to the apparatus housing 203, the position of the output shaft 201 is determined by the applied pressure on the first and second contact surfaces. There is a method of fixing by shifting from an equal position.

  Modification 3 will be described.

  In the present embodiment, a method has been described in which the two pressing members 107a and 107b having different spring stiffnesses are used, and the position of the output shaft is displaced by an external force so that the applied pressures of the two contact surfaces are different.

  As a modification, two pressure members 107a and 107b having the same spring rigidity are used, and a method in which the bending amounts of the two pressure members 107a and 107b are made different in advance can be considered.

  Modification 4 will be described.

  In the present embodiment, the vibration wave motor including the two vibrators 101a and 101b and the two moving bodies 104a and 104b has been described. However, the present invention is not limited to this configuration, and a plurality of vibration wave motors having the same direction of pressurization are used. Any configuration is possible.

  As a modification, as shown in FIG. 8, there is a configuration in which two vibrators 104a and 104b are provided for one vibrator 101, and the trajectories of the two mobile bodies 104a and 104b are concentric.

  Modification 5 will be described.

  As shown in FIG. 9, in Modification 4 of this embodiment, a component group having two moving bodies 104a and 104b concentrically arranged with respect to one transducer 101 is defined as a first component group, and the transducer is fixed. A configuration in which the members are folded back symmetrically about the member is also conceivable.

In this case, one vibrator and four moving bodies 104a, 104b, 104c, and 104d are included, and the four contact surfaces are pressed in the same direction as the facing direction.
Even in this case, the effect of the present invention can be obtained by not making the pressures of the four contact surfaces all the same.

  Modification 6 will be described.

  In the present embodiment, an example of a rotary vibration wave motor has been described. However, the present invention is not limited to this configuration, and a direct acting type is possible as long as the vibration wave motor has a plurality of contact surfaces and a plurality of pressurization directions are the same. The vibration wave motor may be used.

  Modification 7 will be described.

  In this embodiment, the example of the vibration wave motor that drives the moving body by the elliptical movement of the contact surface of the vibrator has been described. However, the present invention is not limited to this configuration, and the contact surface of the vibrator reciprocates and sticks the moving body. Thus, a vibration wave motor that drives the moving body may be used.

  Modification 8 will be described.

  In the present embodiment, the method of adjusting the applied pressure has been described as the method of adjusting the heat generation amount of the plurality of contact surfaces during friction driving, but is not limited to this method. For example, the amount of heat generated by the plurality of contact surfaces can be adjusted by making the amount of sliding and the sliding speed of the contact surfaces different during friction driving differ between the plurality of contact surfaces.

100a, 100b Parts group 101, 101a, 101b Vibrator 102, 102a, 102b Elastic body 103, 103a, 103b Piezoelectric element 104, 104a, 104b, 104c, 104d Moving body 105, 105a Vibration damping member 106, 106a Friction member 107, 107a, 107b Pressure member 108, 108a, 108b Pressure spring fixing member 109 Vibrator fixing member 110, 110a, 110b Case 111, 111a, 111b Bearing 201 Output shaft 202 Pressure adjusting member 203 Device housing

One aspect of the present invention includes a vibrator having an elastic body to which an electromechanical energy conversion element is bonded, a moving body that contacts the vibrator, a pressurizing member that pressurizes the vibrator and the moving body,
And a pressure adjustment member adjustably configure the pressing force of the pressing member, the movable member and the vibrator is pressurized with a plurality of contact surfaces by the pressure member,
The present invention relates to a vibration wave motor configured to frictionally drive the movable body by movement generated on the plurality of contact surfaces by applying an electric signal to the electro-mechanical energy conversion element.

Claims (6)

A vibrator having an elastic body to which an electro-mechanical energy conversion element is bonded; and a moving body that contacts the vibrator, wherein the vibrator and the moving body are pressurized by a pressure member to form a plurality of contact surfaces. Comprising
Vibration that frictionally drives the movable body by motion generated on the plurality of contact surfaces by applying an electric signal to the electro-mechanical energy conversion element, and outputs a plurality of driving forces by the plurality of contact surfaces by a common output shaft. A wave motor,
A vibration wave motor configured to be capable of adjusting a heat generation amount generated by the friction drive so as to be different between the plurality of contact surfaces. A pressure adjusting member for adjusting the pressure applied by the pressure member;
2. The vibration wave motor according to claim 1, wherein the pressure adjusting member is configured to be able to adjust the heat generation amount by adjusting a pressing force between the plurality of contact surfaces. One vibrator and two movable bodies or two vibrators and one movable body, and two pressure members that pressurize each of the vibrator and two movable bodies,
The two pressure members are connected to the common output shaft, and the pressurizing force of the two pressure members can be adjusted simultaneously by displacement of the output shaft in the axial direction. The vibration wave motor according to claim 1 or 2. A temperature detection sensor for detecting the temperature of the motor during the friction drive and / or the temperature of the surrounding environment, and a pressure adjustment for displacing the output shaft in the axial direction by the temperature detected based on the detection result of the temperature detection sensor Members,
The vibration wave motor according to claim 3, further comprising:   5. The vibration wave according to claim 3, wherein the two pressure members are provided so that pressure directions on a contact surface between the vibrator and the moving body are opposed to each other. motor.   5. The vibration according to claim 3, wherein the two pressurizing members are provided such that the directions of pressurization on the contact surface between the vibrator and the moving body are the same. Wave motor.

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