TWM673978U - Harmonic speed reduction transmission device equipped with strain gauge - Google Patents

Abstract

A harmonic speed reduction transmission device equipped with a strain gauge includes a motor, a harmonic speed reducer, and a rigid gear arranged within a housing. The motor drives the harmonic speed reducer to output a reduced rotational torque. The rigid gear is used to guide the harmonic speed reducer. The rigid gear is formed with at least one truss that is deformable to generate a bending moment and is used to fix the rigid gear within the housing. The strain gauge is attached to the truss to sense the reduced rotational torque output by the harmonic speed reducer, and the structural configuration is refined accordingly.

Description

Harmonic speed reduction transmission device equipped with strain gauge

This novel invention relates to torque sensing of a harmonic speed reduction transmission device, and in particular to a harmonic speed reduction transmission device equipped with a strain gauge.

A strain gauge is made of flexible copper foil. It deforms in response to external forces, generating an electrical signal. Strain gauges are commonly used in conventional deceleration transmissions as torque sensors to detect the torque output.

Harmonic deceleration transmissions are a relatively advanced type of deceleration transmission, commonly used in industrial robots, humanoid robots, or the elbow joints of assistive devices for human limbs to precisely control the degrees of freedom and force output of artificial joints.

A harmonic reduction transmission typically consists of a motor powered by a harmonic reducer. The harmonic reducer utilizes the elastic deformation of metal to output reduced rotational torque. Specifically, the harmonic reducer typically comprises a rigid gear, a flexible gear, and a waveform generator within a housing. The waveform generator consists of an elliptical disc and a flexible bearing tightly bonded to the disc's periphery. The motor can drive the elliptical disc to rotate, and the elliptical disc can sequentially force the flexible bearing and a thin wall portion of the flexible gear to deform into a consistent elliptical shape, thereby driving the flexible gear to rotate in the opposite direction around the rigid gear; during this period, since the number of teeth of the outer teeth of the flexible gear is slightly less than that of the inner teeth of the rigid gear, and the thin wall portion of the flexible gear has been deformed into an elliptical shape, the flexible gear actually has only the outer teeth at the two opposite ends of the elliptical long axis direction that can rotate with the rigid gear. The inner teeth of the rigid gear interlock and rotate slowly on the inner teeth of the rigid gear's circumference. This means that for every 360-degree rotation of the elliptical disc, the flexible gear can only rotate a small arc of the 360-degree rotation in the opposite direction (depending on the number of teeth reduced on the flexible gear's outer teeth). This makes the flexible gear rotate much slower than the elliptical disc, achieving a reduction effect. The rotational torque of a predetermined reduction ratio is then output through a thick wall portion of the flexible gear.

The existing patent TWI640756B has representatively disclosed a technique for installing a strain gauge within a planetary gear-type reduction transmission device to detect its output torque. However, the strain gauge in this patent is mounted on a torque sensing disk. The torque output by the rigid gear (or ring gear) must be transmitted to the torque sensing disk before it can be sensed by the strain gauge. This can easily reduce the accuracy of the strain gauge's sensed output torque.

Furthermore, existing patents JP-5659446B2 and CN109895122B have representatively disclosed the aforementioned harmonic reducer application technology. JP6496937B2, CN109895112B, CN103610568B, and US9855654 also teach directly mounting various torque sensing elements (or sensors) on the movable element that transmits the decelerated rotational torque output. However, the techniques taught in these patents can easily limit the accuracy of the torque sensing element's torque sensing. Furthermore, the wires connected to the torque sensing element can easily rotate with the movable element, causing the wires to become tangled or damaged.

In light of the technical shortcomings of prior art, this novel design specifically improves the structure of the reduction gear mechanism, eliminating the need for the torque sensor to be mounted on the movable element and enabling it to directly sense the torque output from the rigid gear. This improves the accuracy of the reduction gear mechanism's output torque sensing and overcomes the problem of the torque sensor's wires easily becoming tangled.

To this end, a preferred embodiment of the present invention utilizes a strain gauge as the torque sensing element, thereby providing a strain gauge-equipped harmonic speed reduction transmission device. The primary technical approach involves arranging a motor, a harmonic speed reducer, and a rigid gear coaxially within a metal housing. The motor comprises a stator fixed within the housing and a rotor pivotally mounted within the stator. The harmonic speed reducer is coupled to the rotor and outputs a reduced rotational torque. The rigid gear, fixed within the housing, guides the harmonic speed reducer and thereby withstands the torque of the harmonic speed reducer. Furthermore, the rigid gear is formed with an annular end surface of constant circumferential radius. This annular end surface extends along the axis to form at least one truss capable of generating a bending moment. The rigid gear is secured within the housing via the truss, and the strain gauge is attached to the truss to sense the decelerated rotational torque output by the harmonic reducer.

Based on the aforementioned technical approach, the present invention differs from prior art in that neither the housing nor the rigid gears affixed therein are movable elements used to transmit the decelerated rotational torque output, thereby avoiding the problem of strain gauge wires causing entanglement. Furthermore, the present invention utilizes the rigid gears to simultaneously withstand the torque applied to the decelerated rotational torque output by the harmonic reducer. This causes the truss to deform in response to the applied torque, generating a corresponding bending moment due to the mechanical properties of its metal material. This, in turn, causes the strain gauge to follow the truss deformation and generate an electrical potential signal, which is used to determine the decelerated rotational torque output by the harmonic reducer. The deformation generated by the truss and the strain gauge is proportional to the output torque. Furthermore, the present invention can improve the accuracy of the harmonic reduction transmission device in sensing the output torque, at least based on the structural configuration characteristics of the truss.

In further embodiments, the cross-section of the truss may be rectangular, strip-shaped, or M-shaped, and the trusses may be formed in pairs on the annular end surface. When the cross-section of the truss is rectangular, the two long sides of the rectangle are perpendicular to the tangent of the annular end surface, and the two short sides of the rectangle are parallel or collinear with the tangent of the annular end surface. The strain gauge is attached to a radial end surface formed by extending from any of the long sides. Alternatively, when the truss is strip-shaped, the radial end surface to which the strain gauge is attached may be formed by extending from at least one long side of the strip. Furthermore, when the truss is M-shaped and has two symmetrical strips, each strip having two symmetrical long sides, the radial end surface to which the strain gauge is attached may be formed by extending from any of the long sides.

In one alternative embodiment, the annular end surface is formed with a pair of engaging grooves, and the bottom portion of the truss is formed with an engaging portion that can be fixed to the engaging grooves. The truss is formed on the annular end surface via the engaging portions. Furthermore, the annular end surface may extend along the axis to form a convex platform, with the engaging grooves formed between the convex platform and the annular end surface.

A further embodiment includes: the housing is formed of a base and a cover pivotally connected to each other. The rigid gear is fixed to the base of the housing via the truss and extends into the cover to guide the harmonic reducer. The base provides a fixed position for the stator and the rigid gear, while the cover accommodates and provides a transmission connection for the harmonic reducer, serving as a power output terminal of the harmonic reduction transmission device.

The harmonic reducer includes a waveform generating group and a flexible gear. The waveform generating group includes an elliptical disc drivingly connected to the rotor and a flexible bearing coupled between the elliptical disc and the flexible gear. The harmonic reducer is guided by the rigid gear via the flexible gear. The rigid gear comprises a plurality of annularly distributed inner teeth, while the flexible gear comprises a thin-walled portion capable of deformation and a thick-walled portion capable of maintaining rigidity. The thin-walled portion has a smooth inner wall and a plurality of annularly distributed outer teeth surrounding the thin-walled portion. The flexible gear engages the flexible bearing via the inner wall, and the outer teeth engage a portion of the inner teeth of the rigid gear. Furthermore, the housing secures the stator and the rigid gear. The flexible gear is connected to the housing via the thick-walled portion, driving the housing to serve as a power output port for the harmonic reduction transmission.

Furthermore, the rotor is formed with a central hub, and the housing is formed with a central seat portion that can extend into the central hub. The rotor is pivoted between the central seat portion and the stator via the central hub. The central seat portion is formed with a seat hole, and a central post is formed in the housing. The housing is pivotally connected to the housing via the central post.

Compared to existing technologies, this new technology not only effectively improves the accuracy of output torque sensing and prevents the strain gauge's wiring from snagging, but also enhances the strain gauge's configuration stability and durability. Furthermore, it also allows for a more compact and compact structure and internal space within the harmonic reduction transmission.

The implementation details and technical effects disclosed above will be more specifically illustrated in the following figures and implementation methods.

10: Shell

11: Shell

111: Center seat

112: Seat hole

12: Shell

121: Center Column

20: Motor

21: Stator

22: Rotor

221: Center hub

31: Harmonic reducer

310: Waveform Generation Group

311: Flexible gear

312: Thin-walled section

312a: Inner wall

312b: External teeth

313: Thick wall section

314:Oval Plate

315: Flexible bearing

40: Rigid gear

41: Inner teeth

42: Ring end face

421: Embedded Groove

43,44: Truss

430,440: Radial end face

431: Joint

432,442: Embedding part

433,443: Long side

434,444: Short side

441: Strips

50: Strain gauge

61: First bearing

62: Second bearing

63: Third bearing

64: Fourth bearing

Figure 1 is a schematic 3D exploded diagram of the novel harmonic speed reduction transmission device.

Figure 2 is a cross-sectional view of Figure 1.

Figure 3a is a partial cross-sectional view of Figure 2, revealing the configuration of the truss on the rigid gear and the strain gauge attached to the truss.

Figure 3b is an explanatory diagram of the motion of Figure 3a, illustrating how the strain gauge senses torque as the truss deforms.

Figure 3c is a cross-sectional view of the truss shown in Figure 3a.

Figure 3d is a schematic three-dimensional diagram of the truss and rigid gear shown in Figure 3a implemented as a separate structure.

Figure 4a is a schematic exploded perspective view of another embodiment of forming a truss on the rigid gear shown in Figure 2.

Figure 4b is a schematic perspective view of another embodiment of a truss formed on the rigid gear shown in Figure 2, illustrating a detachable assembly configuration between the truss and the annular end surface.

First, please refer to Figures 1 and 2 together, which illustrate the configuration of the first embodiment of the present invention. The harmonic reduction transmission device comprises a housing 10 made of metal. Within the housing 10, a motor 20, a harmonic reducer 31, a rigid gear 40, and a strain gauge 50 can be arranged along a common axial trajectory. The axial trajectory is indicated by the centerline in Figure 2.

The motor 20 can be a brushless DC motor or a permanent magnet AC synchronous motor, and includes a stator 21 fixed within the housing 10 and a rotor 22 pivotally disposed within the stator 21. The rotor 22 is formed with a central pivot hole 221.

The harmonic speed reducer 31 is used to drive the rotor 22 and convert the rotational torque provided by the rotor 22 into a reduced rotational torque, which is then output to the device on which the harmonic speed reduction transmission device is installed.

The harmonic reducer 31 includes a waveform generating assembly 310 and a flexible gear 311. The waveform generating assembly 310 comprises an elliptical disc 314 drivingly connected to the rotor 22 and a flexible bearing 315 coupled between the elliptical disc 314 and the flexible gear 311. The flexible gear 311 comprises a thin-walled portion 312 capable of deformation and a thick-walled portion 313 capable of maintaining rigidity. The thin-walled portion 312 has a smooth inner surface 312a and a plurality of outer teeth 312b annularly distributed around the thin-walled portion 312. The flexible gear 311 couples to the flexible bearing 315 via the inner surface 312a.

The rigid gear 40 is also made of a rigid metal material and has multiple inner gears 41 distributed in a ring shape. The rigid gear 40 is also fixed within the housing 10 along the axis. Consequently, the multiple outer gears 312b of the flexible gear 311 can contact some of the inner gears 41 of the rigid gear 40, allowing the rigid gear 40 to provide guidance for the flexible gear 311 of the harmonic reducer 31.

Furthermore, the rigid gear 40 is formed with an annular end surface 42 of uniform circumferential radius. Extending along the axis, the annular end surface 42 is formed with a pair of flexible trusses 43, enabling the rigid gear 40 to be secured within the housing 10 via the trusses 43. The trusses 43 do not necessarily need to be in pairs; in practice, forming a single or multiple trusses 43 on the annular end surface 42 is within the scope of the present invention's adaptable applications and is described herein. Furthermore, referring to Figure 3a, the truss 43 is integrally formed on the annular end surface 42 and is arranged in an upright position. An anchor portion 431 is formed at one end of the truss 43. The truss 43 can be secured to a top wall of the housing 10 by means of a screw threaded through the anchor portion 431.

As shown in Figures 1 and 2 , the strain gauge 50 can be attached to the truss 43. Specifically, the strain gauge 50 is made of a flexible copper foil sheet. When subjected to tension, compression, or torsion by an external force, it deforms and generates an electrical potential signal. The amount of deformation generated by the strain gauge 50 under the external force is proportional to the output torque. In other words, the greater the external force, the greater the deformation of the strain gauge 50, and the greater the output torque indicated by the electrical potential signal, and vice versa. Furthermore, the truss 43 is formed with at least one radial end surface 430 . The radial end surface 430 is a plane located radially of the rigid gear 40 . The strain gauge 50 is attached to the radial end surface 430 of the truss 43 , thereby becoming integral with the truss 43 .

Based on the configuration technology disclosed in the first embodiment, the present invention can utilize the potential signal generated by the strain gauge 50 to read and determine the deceleration torque output by the harmonic reducer 31 using a conventional logic controller.

Specifically, as shown in FIG2 , when the stator 21 of the motor 20 drives the rotor 22 to rotate, the elliptical disc 314 is driven to rotate accordingly, and the flexible bearing 315 and the thin wall portion 312 of the flexible gear 311 are forced to deform into a consistent elliptical shape, thereby driving the flexible gear 311 to rotate in the opposite direction around the rigid gear 40. At this time, due to the outer teeth 31 of the flexible gear 311 The number of teeth on the flexible gear 311 is less than the number of inner teeth 41 of the rigid gear 40 (typically two fewer), and the thin-walled portion 312 of the flexible gear 311 has been deformed into an elliptical shape. This allows only the outer teeth 312b at the two opposite ends of the ellipse's major axis to intersect with a portion of the inner teeth 41 of the rigid gear 40, allowing the flexible gear 311 to rotate slowly on the inner teeth 41 of the rigid gear 40.

In other words, the rotor 22 drives the elliptical disc 314 to rotate one revolution (360 degrees), causing the flexible gear 311 to rotate in the opposite direction by a small arc (depending on the number of teeth reduced on the flexible gear's outer gear). This means that the rotational speed of the flexible gear 311 is relatively slower than the rotational speed generated by the rotor 22, thereby achieving a harmonic reduction effect. This allows the harmonic reducer 31 to output a reduced rotational torque with a predetermined reduction ratio through the flexible gear 311. During this reduction transmission process, the rigid gear 40 not only guides the flexible gear 311 but also absorbs the torque transmitted by the flexible gear 311.

3a and 3b, FIG3a shows that when the rigid gear 40 is not subjected to torsion, the truss 43 and the strain gauge 50 are not deformed, so that the strain gauge 50 does not generate the potential signal. Figure 3b reveals that when the rigid gear 40 is subjected to the torque M transmitted by the flexible gear 311, it causes the truss 43 to experience a bending moment, generating a deformation δ. At this point, the strain gauge 50, fixed to the radial end surface 430 of the truss 43, deforms along with the truss 43. The greater the torque M transmitted by the flexible gear 311 on the rigid gear 40, the greater the deformation δ of the truss 43 and the strain gauge 50, resulting in a larger potential signal generated by the strain gauge 50, and vice versa. Thus, the present invention can read and determine the deceleration torque value based on the strength of the potential signal.

Please refer to Figure 3c, which reveals that the cross-section of the middle section of the truss 43 shown in Figure 1 is a rectangle formed by two long sides 433 and two short sides 434. The two long sides 433 are respectively perpendicular to the tangent L of the annular end surface 42, and the two short sides 434 are respectively parallel to or collinear with the tangent L of the annular end surface 42. Therefore, the truss 43 with a rectangular cross-section can generate the deformation of the bending moment by virtue of the relative thinness constructed by the two short sides 434. The radial end surface 430 can be formed by extending from either of the two long sides 433, or by symmetrically extending from both long sides 433. Furthermore, the long sides 433 form the radial end surface 430 along the radial direction of the rigid gear 40 and the axis of the axis. Furthermore, the strain gauge 50 can be fixed to the truss individually or in pairs as shown in Figure 3a. It is understood that the more strain gauges 50 are attached, the more accurately the deceleration torque output by the harmonic reducer 31 can be detected.

Furthermore, the truss 43 shown in Figures 1 and 3c can also be defined as a strip, similarly having two long sides 433 and two short sides 434. Similarly, the radial end face 430 shown in Figures 2, 3a, and 3b can be formed by extending from either or both of the long sides 433, thereby providing a suitable location for the strain gauge 50 to be attached.

Referring further to Figure 3d, it is revealed that the truss 43 shown in Figure 1 can be removably fixed to the annular end surface 42. Specifically, the annular end surface 42 is formed with a pair of retaining grooves 421. The bottom of the truss 43 is formed with a retaining portion 432 that can be engaged and fixed to the retaining grooves 421. This allows the truss 43 to be mounted within the retaining grooves 421 of the annular end surface 42 via the retaining portions 432, thereby being formed on the annular end surface 42. This simplifies the manufacturing process of the rigid gear 40.

FIG4a also shows another embodiment of a truss 44 positioned between the annular end surface 42 and the housing 10. Specifically, the truss 44 can be formed into a flexible M-shape, with two symmetrical strips 441. Each strip 441 has two symmetrical long sides 443 and two symmetrical short sides 444 (see FIG3c ). This allows the truss 44 to generate the bending moment deformation through the relative thinness of the two short sides 444. The radial end surface 440 can be formed by extending from either or both of the two long sides 443 shown in FIG4a , allowing the strain gauge 50 to be attached to at least one of the radial end surfaces 440 formed by extending from either or both of the long sides.

As shown in Figure 4b, the truss 44 shown in Figure 4a can be removably fixed to the annular end surface 42. Specifically, the annular end surface 42 is formed with a pair of retaining grooves 421. The bottom of the truss 44 is formed with a retaining portion 442 that can be fixed to the retaining grooves 421. This allows the truss 44 to be mounted within the retaining grooves 421 of the annular end surface 42 via the retaining portions 442, thereby being formed on the annular end surface 42. This also simplifies the manufacturing process of the rigid gear 40.

The first embodiment further discloses that the housing 10 can be annular and comprised of an annular housing 11 and an annular housing cover 12 pivotally connected to each other. Furthermore, as shown in Figures 1 and 2 , the housing 11 can be considered the fixed end of the transmission device, for being locked onto the end of a device that requires the reduced rotational torque. The center of the housing 11 forms a central seat 111 with a seat hole 112 defined therein. The housing cover 12 also has a central post 121 formed in the center that extends into the seat hole 112. A first bearing 61 is mounted between the seat hole 112 and the post 121. Furthermore, a second bearing 62 and a third bearing 63 are mounted between the periphery of the housing 11 and the housing cover 12, enabling the housing cover 12 to be pivotally connected to the housing 11 via the post 121, the first bearing 61, the second bearing 62, and the third bearing 63.

Furthermore, the housing 10 secures the stator 21 and the rigid gear 40 via the housing 11. The rotor 22 is pivoted between the outer wall of the central seat 111 and the stator 21 via at least one fourth bearing 64 disposed within the central pivot hole 221. The housing cover 12 secures the thick-walled portion 313 of the flexible gear 311, allowing the decelerated rotational torque output by the flexible gear 311 to be provided to the device through the housing cover 12 as a power output terminal.

In the above description, the central seat portion 111 and seat hole 112 of the housing 11 may alternatively be formed within the housing cover 12. In this way, the central column 121 of the housing cover 12 is also formed within the housing 11. In other words, as long as the housing 11 and the housing cover 12 can be pivotally connected and have interconnected internal accommodating chambers, they are all within the scope of application of this novel convertible implementation.

As demonstrated by the aforementioned embodiments, the present invention effectively improves the accuracy of output torque sensing in a harmonic reduction transmission and overcomes the problem of tangling of the torque sensing element's wires. Furthermore, the aforementioned embodiments merely illustrate preferred implementations of the present invention and should not be construed as limiting the scope of the patent application. Therefore, the present invention shall be governed by the claims defined in the patent application.

10: Shell

11: Shell

111: Center seat

112: Seat hole

12: Shell

121: Center Column

20: Motor

21: Stator

22: Rotor

221: Center hub

31: Harmonic reducer

310: Waveform Generation Group

311: Flexible gear

312: Thin-walled section

312a: Inner wall

312b: External teeth

313: Thick wall section

314:Oval Plate

315: Flexible bearing

40: Rigid gear

41: Inner teeth

42: Ring end face

43: Truss

431: Joint

50: Strain gauge

Claims (13)

A strain gauge-equipped harmonic speed reduction transmission device is configured in a housing along a coaxial track and includes: a motor comprising a stator fixed in the housing and a rotor pivotally mounted in the stator; a harmonic speed reducer drivingly connected to the rotor and outputting a reduced rotational torque; a rigid gear fixed in the housing to guide the harmonic speed reducer and thereby withstand the harmonic The torque action of the harmonic reducer is generated by the rigid gear, wherein the rigid gear is formed with an annular end surface with a constant circumferential radius, and the annular end surface extends along the axial track to form at least one truss that can generate a deformation that generates a bending moment. The rigid gear is fixed in the housing via the truss, and the strain gauge is attached to the truss to sense the deceleration rotational torque output by the harmonic reducer. A harmonic deceleration transmission device equipped with a strain gauge as described in claim 1, wherein the cross-section of the truss is rectangular, the two long sides of the rectangle are respectively perpendicular to the tangent of the annular end face, the two short sides of the rectangle are respectively parallel to or collinear with the tangent of the annular end face, and the strain gauge is attached to a radial end face formed by extending from any of the long sides. A harmonic deceleration transmission device equipped with a strain gauge as described in claim 1, wherein the truss is in the form of a strip located between the annular end surface and the housing, at least one long side of the strip extends to form a radial end surface, and the strain gauge is attached to the radial end surface. A harmonic deceleration transmission device equipped with a strain gauge as described in claim 1, wherein the truss is M-shaped and located between the annular end surface and the device housing, the M-shape has two symmetrical strips, each of the strips has two symmetrical long sides, and the strain gauge is attached to a radial end surface formed by extending from any of the long sides. The harmonic deceleration transmission device equipped with a strain gauge as described in claim 1, wherein the trusses are formed in pairs on the annular end surface. A harmonic deceleration transmission device equipped with a strain gauge as described in any one of claims 1 to 5, wherein the annular end surface is formed with a pair of embedding grooves corresponding to the trusses, and the bottom of the trusses is respectively formed with an embedding portion that can be fixed to the embedding grooves, and the trusses are formed on the annular end surface via the embedding portions. The harmonic speed reduction transmission device equipped with a strain gauge as described in claim 6, wherein the annular end surface extends along the axial track to form a convex platform, and the embedding grooves are respectively formed between the convex platform and the annular end surface. A strain gauge-equipped harmonic speed reducer transmission device as described in any one of claims 1 to 5, wherein the housing is composed of a housing seat and a housing cover pivotally connected to each other, the rigid gear is fixed in the housing seat of the housing via the truss and extends into the housing cover to guide the harmonic speed reducer. A strain gauge-equipped harmonic speed reducer transmission device as described in any one of claims 1 to 5, wherein the device housing is composed of a housing and a housing cover pivotally connected to each other, the housing providing fixation for the stator and the rigid gear, and the housing cover accommodating and providing a transmission connection for the harmonic speed reducer, serving as a power output terminal of the harmonic speed reducer transmission device. A harmonic speed reduction transmission device equipped with a strain gauge as described in claim 1, wherein the harmonic speed reducer includes a waveform generating group and a flexible gear, the waveform generating group includes an elliptical disk drivingly connected to the rotor and a flexible bearing coupled between the elliptical disk and the flexible gear, and the harmonic speed reducer is guided by the rigid gear by means of the flexible gear. A harmonic speed reduction transmission device equipped with a strain gauge as described in claim 10, wherein the rigid gear is formed with a plurality of inner teeth distributed in an annular manner, the flexible gear is formed with a thin-walled portion capable of generating deformation and a thick-walled portion capable of maintaining rigid strength, the thin-walled portion has a smooth inner wall surface and a plurality of outer teeth distributed in an annular manner on the periphery of the thin-walled portion, the flexible gear is coupled to the flexible bearing via the inner wall surface and the outer teeth contact part of the inner teeth of the rigid gear. A harmonic speed reduction transmission device equipped with a strain gauge as described in claim 11, wherein the device housing is composed of a housing and a housing cover pivotally connected to each other, the housing provides fixation for the stator and the rigid gear, and the flexible gear is connected to the housing cover through the thick wall portion, driving the housing cover to become a power output end of the harmonic speed reduction transmission device. A harmonic deceleration transmission device equipped with a strain gauge as described in claim 1, wherein the rotor is formed with a central hub, the device housing is formed by a housing and a housing cover pivotally connected to each other, the housing is formed with a central seat portion that can extend into the central hub, the rotor is pivoted between the central seat portion and the stator via the central hub, the central seat portion is formed with a seat hole, a central column is extended into the housing cover, and the housing cover is pivotally connected to the housing via the central column.