Series of gear motors

Abstract

Provided is a series of gear motors comprising a first gear motor and a second gear motor. The first gear motor 100 includes a first motor 102 and a first speed reducer 104. The second gear motor includes a second motor common to the first motor and a second speed reducer. The first speed reducer 104 includes a first input shaft 122 and a first speed reduction mechanism 124. The second speed reducer includes a second input shaft and a second speed reduction mechanism different from the first speed reduction mechanism. The first input shaft 122 is connected to a motor shaft of the first motor 102 so as to be integrally rotatable by float connection. The second input shaft is connected to a motor shaft of the second motor so as to be integrally rotatable by float connection.

Description

Series of gear motors

[0001] This disclosure relates to a series of gear motors.

[0002] Patent Document 1 discloses a series of gear motors. This series of gear motors includes, for example, a first gear motor and a second gear motor. The first gear motor includes a first motor and a first speed reducer (e.g., a parallel shaft gear speed reducer). The second gear motor includes a second motor common to the first motor and a second speed reducer (e.g., a planetary gear speed reducer). The first speed reducer includes a first input shaft composed of a pinion gear, and the second speed reducer includes a second input shaft composed of a pinion gear.

[0003] Japanese Patent Application Laid-Open No. 2021-078296

[0004] In the disclosed technology of Patent Document 1, each of the first and second input shafts is integrally rotatably connected to the motor shafts of the first and second motors by press-fitting. Therefore, when assembling each of the first and second gear motors, it is necessary to connect each of the first and second input shafts to the motor shaft by press-fitting, and there is a problem in workability.

[0005] One of the objects of this disclosure is to provide a technique for improving the workability during the assembly work of each of the first and second gear motors.

[0006] One aspect of this disclosure is a series of gear motors including a first gear motor and a second gear motor, wherein the first gear motor includes a first motor and a first speed reducer, the second gear motor includes a second motor common to the first motor and a second speed reducer, the first speed reducer includes a first input shaft and a first speed reduction mechanism, the second speed reducer includes a second input shaft and a second speed reduction mechanism different from the first speed reduction mechanism, the first input shaft is integrally rotatably connected to the motor shaft of the first motor by a floating connection, and the second input shaft is integrally rotatably connected to the motor shaft of the second motor by a floating connection.

[0007] According to this disclosure, the workability during the assembly work of each of the first and second gear motors is improved.

[0008] This is a side cross-sectional view showing the first gear motor of the first embodiment. This is a view of a part of the first motor of the first embodiment from the axial non-load side. This is an enlarged view of a part of Figure 1. This is a side cross-sectional view showing the second gear motor of the first embodiment. This is an enlarged view of a part of the fourth. This is a schematic diagram showing the case where the fastening point of the adapter to the load-side motor cover is moved away from the reduction gear casing to the non-load side. This is an explanatory diagram of the radial clearance. This is an explanatory diagram of the sub-series of the gear motor of the second embodiment.

[0009] Embodiments for carrying out the series of gear motors of this disclosure are described below. The same or equivalent elements are denoted by the same reference numerals, and redundant descriptions are omitted. In each drawing, components are omitted, enlarged, or reduced as appropriate for ease of explanation. The drawings should be viewed in accordance with the orientation of the reference numerals.

[0010] This section describes a series of gear motors. The gear motor series described below can also be understood as a series of manufacturing methods and design methods for the gear motors themselves.

[0011] Refer to Figures 1 and 4. The gear motor series comprises a first gear motor 100 and a second gear motor 200. The first gear motor 100 comprises a first motor 102 and a first reduction gear 104. The second gear motor 200 comprises a second motor 202 and a second reduction gear 204.

[0012] The first and second gear motors 100 and 200 share many common components. To distinguish these common components, the components of the first gear motor 100 are prefixed with "1st," and the components of the second gear motor 200 are prefixed with "2nd." Furthermore, the symbols for these common components have the same last two digits, and are distinguished by the hundreds digit. The components of the first gear motor 100 are prefixed with numbers in the 100s, and the components of the second gear motor 200 are prefixed with numbers in the 200s. When describing these common components, the prefixes "1st" and "2nd" are omitted.

[0013] The first gear motor 100 will be explained first. Refer to Figures 1 and 2. In Figure 1, the first motor 102 and the first adapter 132 are shown in cross-section along the line I-I in Figure 2. Similarly, the parts of the first reduction gear 104 other than the first adapter 132 are shown in cross-section along the line I-I' in Figure 2. The same applies to the second motor 202 and the second reduction gear 204 in Figure 4. In Figure 2, only the outer surfaces of the motor casings 112 and 212 are shown, and the internal structure is omitted. Also, in Figure 2, for the sake of explanation, the reference numerals for the components of both the first and second motors 102 and 202 are shown.

[0014] In describing the gear motors 100 and 200, the direction along the rotational centerline of the motor shafts 106 and 206 is simply referred to as the axial direction, and the radial and circumferential directions relative to that rotational centerline are simply referred to as the radial and circumferential directions. Furthermore, in the axial direction, the side of the motor 102 and 202 with the reduction gear (left side of Figure 1) is referred to as the load side, and the opposite side in the axial direction (right side of Figure 1) is referred to as the non-load side.

[0015] The motors 102 and 202 each include motor shafts 106 and 206, stators 108 and 208 and rotors 110 and 210, motor casings 112 and 212 that house the motor shafts 106 and 206, stators 108 and 208, rotors 110 and 210, etc., and at least two motor shaft bearings 114 and 214 that rotatably support the motor shafts 106 and 206. The two motor shaft bearings 114 and 214 include load-side motor shaft bearings 114A and 214A located on the load side and non-load-side motor shaft bearings 114B and 214B located on the non-load side.

[0016] The stators 108 and 208 are fixed to the motor casings 112 and 212 by interlocking or other means, and are capable of generating a rotating magnetic field. The rotors 110 and 210 can rotate together with the motor shafts 106 and 206 due to the rotating magnetic field generated by the stators 108 and 208. The types of stators 108 and 208 and rotors 110 and 210 are not particularly limited, and various types of stators and rotors can be used.

[0017] The motor casings 112 and 212 include cylindrical motor frames 116 and 216, load-side motor covers 118 and 218 provided on the load side relative to the motor frames 116 and 216, and non-load-side motor covers 120 and 220 provided on the non-load side relative to the motor frames 116 and 216.

[0018] The load-side motor covers 118 and 218 cover the rotors 110 and 210 and the stators 108 and 208 from the load side. The load-side motor covers 118 and 218 support the motor shafts 106 and 206 via the load-side motor shaft bearings 114A and 214A. The outer rings of the load-side motor shaft bearings 114A and 214A are fitted into the load-side motor covers 118 and 218 by interference fit or the like. The non-load-side motor covers 120 and 220 support the motor shafts 106 and 206 via the non-load-side motor shaft bearings 114B and 214B.

[0019] At least two motor shaft bearings 114, 214 can withstand the moment load acting on the motor shafts 106, 206. To achieve this, the load-side motor shaft bearings 114A, 214A and the non-load-side motor shaft bearings 114B, 214B are positioned at axial intervals. The motor shafts 106, 206 can similarly withstand the radial load acting on them. In this specification, a moment load refers to a load that tilts the rotational centerline of the rotational shafts (in this case, the motor shafts 106, 206).

[0020] Each reduction gear 104, 204 comprises input shafts 122, 222 to which rotation is input from motor shafts 106, 206; reduction mechanisms 124, 224 to which the rotation of the input shafts 122, 222 is reduced; output members 126, 226 to which the rotation reduced by the reduction mechanisms 124, 224 is output to the driven element; reduction gear casings 130, 230 provided with reduction gear internal spaces 128, 228 that house at least a part of the reduction mechanisms 124, 224; adapters 132, 232 connecting the reduction gear casings 130, 230 to the motor casings 112, 212; and at least two input shaft bearings 134, 234 that rotatably support the input shafts 122, 222. The input shaft bearings 134 and 234 include load-side input shaft bearings 134A and 234A, which are located on the load side, and non-load-side input shaft bearings 134B and 234B, which are located on the non-load side.

[0021] The input shafts 122 and 222 are rotatably supported by the reduction gear casings 130 and 230 or the adapters 132 and 232 via at least one bearing. In the first gear motor 100, the first input shaft 122 is rotatably supported by bearings in the first reduction gear casing 130 and the first adapter 132, respectively. Specifically, the first input shaft 122 is supported by the first adapter 132 via a first non-load side input shaft bearing 134B. The first input shaft 122 is also supported by the first reduction gear casing 130 via a first load side input shaft bearing 134A and two main bearings 136 positioned between the first reduction gear casing 130 and the first output member 126.

[0022] The first reduction mechanism 124 in this embodiment includes a center crank type eccentric oscillating reduction mechanism. The first reduction gear 104 using this includes a crankshaft 138 having an eccentric portion 138a, an external gear 140 that oscillates due to the eccentric portion 138a, and an internal gear 142 that meshes with the external gear 140. The eccentric portion 138a of the crankshaft 138 is provided separately from and integrally rotatable with the shaft portion 138b, which is provided radially inward of the crankshaft 138 relative to the eccentric portion 138a. Alternatively, the shaft portion 138b and the eccentric portion 138a may be integrally provided from the same member. The first input shaft 122 in this embodiment is composed of the shaft portion 138b of the crankshaft 138.

[0023] The external gear 140 and the internal gear 142 constitute the first reduction mechanism 124. In the first gear motor 100 of this embodiment, a part of the internal gear 142 is also the first reduction gear casing 130, and its internal teeth are made up of pins and rollers supported by the first reduction gear casing 130. The first output member 126 can be synchronized with the rotation component of the external gear 140 by a pin 144 that protrudes from the first output member 126 and penetrates the external gear 140. When the crankshaft 138, which is the first input shaft 122, rotates, the external gear 140 oscillates due to the eccentric portion 138a of the crankshaft 138, causing it to rotate, and this rotation component is transmitted to the first output member 126 by the pin 144. In this process, the first reduction mechanism 124 transmits a rotation reduced from the rotation of the first input shaft 122 to the first output member 126. The first output member 126 outputs the reduced rotation transmitted from the first reduction mechanism 124 to the driven machine (not shown).

[0024] In this embodiment, the output members 126 and 226 are provided separately from the gearbox casings 130 and 230. In addition, depending on the type of gearbox 104 and 204, the output members 126 and 226 may also be provided by the gearbox casings 130 and 230.

[0025] The internal spaces 128 and 228 of the reduction gear house various components of the reduction gears 124 and 224, depending on the type of reduction gear 124 and 224. For example, the internal space 128 of the first reduction gear houses the external gear 140, as well as the pins and rollers that constitute the internal teeth of the internal gear 142.

[0026] The internal spaces 128 and 228 of the gearbox are sealed by a plurality of gearbox sealing members 146 and 246. The number and position of the gearbox sealing members 146 and 246 vary depending on the type of gearbox 104 and 204. For example, in the first gear motor 100, one first gearbox sealing member 146 is positioned between the first adapter 132 and the first input shaft 122. In addition, other first gearbox sealing members 146 are positioned between the first gearbox casing 130 and the first output member 126. At least a lubricant (not shown) for lubricating the reduction mechanisms 124 and 224 is sealed in the internal spaces 128 and 228 of the gearbox.

[0027] The gearbox casings 130 and 230 are provided with mounting portions 130a for attachment to the mounting portion of the driven machine. The first mounting portion 130a of the first gearbox casing 130 is composed of legs. The specific example of the mounting portion 130a is not particularly limited and may be composed of a flange portion or the like.

[0028] The adapters 132 and 232 are connected to the gearbox casings 130 and 230 by bolts B1, etc., and are also connected to the load-side motor covers 118 and 218 by adapter bolts B2, etc. The adapters 132 and 232 cover the internal spaces 128 and 228 of the gearbox from the non-load side. The adapters 132 and 232 support the input shafts 122 and 222 via the non-load-side input shaft bearings 134B and 234B. A gearbox sealing member 146 or 246 is positioned between the adapters 132 and 232 and the input shafts 122 and 222.

[0029] The load-side motor covers 118 and 218 are provided with cover-side fitting surfaces 118a and 218a that engage with the adapters 132 and 232 in a spigot-like manner. The adapters 132 and 232 are provided with adapter-side fitting surfaces 132a and 232a that engage with the cover-side fitting surfaces 118a and 218a of the load-side motor covers 118 and 218 in a spigot-like manner. The cover-side fitting surfaces 118a and 218a and the adapter-side fitting surfaces 132a and 232a are composed of a combination of radially opposing inner and outer circumferential surfaces. In this embodiment, the cover-side fitting surfaces 118a and 218a are inner circumferential surfaces and the adapter-side fitting surfaces 132a and 232a are outer circumferential surfaces, but the reverse may also be true. These spigot fittings allow for easy positioning of the relative positions of the motors 102, 202 and the reducers 104, 204 in the radial direction when connecting the motor shafts 106, 206 and the input shafts 122, 222.

[0030] At least two input shaft bearings 134 and 234 are capable of receiving moment loads acting on the input shafts 122 and 222. To achieve this, the load-side input shaft bearings 134A and 234A and the non-load-side input shaft bearings 134B and 234B are positioned at axial intervals. The input shafts 122 and 222 are also capable of receiving radial loads acting on them. The two input shaft bearings 134 and 234 are positioned according to the type of reduction gear 104 and 204. For example, the first load-side input shaft bearing 134A is positioned between the first output member 126 and the first input shaft 122. The first non-load-side input shaft bearing 134B is positioned between the first adapter 132 and the first input shaft 122.

[0031] Refer to Figure 3. The motor shafts 106, 206 and the input shafts 122, 222 are separate components. One of the motor shafts 106, 206 and the input shafts 122, 222, namely one shaft 148, 248, has hollow sections 148a, 248a, and the other shaft 150, 250, namely the other shaft 150, 250, is inserted into the hollow sections 148a, 248a. In this embodiment, the motor shafts 106, 206 become the one shafts 148, 248, and the input shafts 122, 222 become the other shafts 150, 250. Alternatively, the input shafts 122, 222 may be the one shafts 148, 248 with hollow sections 148a, 248a, and the motor shafts 106, 206 may be the other shafts 150, 250, inserted into the hollow sections 148a, 248a.

[0032] The motor shafts 106 and 206 are provided with motor shaft side connection portions 106a and 206a that are connected to the input shafts 122 and 222 so as to be rotatable together. The input shafts 122 and 222 are provided with input shaft side connection portions 122a and 222a that are connected to the motor shafts 106 and 206 so as to be rotatable together. In this embodiment, each connection portion 106a, 206a, 122a, and 222a is provided within the hollow portions 148a and 248a of the single shaft 148 and 248.

[0033] In this embodiment, the motor shaft side connection parts 106a, 206a and the input shaft side connection parts 122a, 222a are connected so as to be able to rotate as a whole by a spline structure. Alternatively, the motor shaft side connection parts 106a, 206a and the input shaft side connection parts 122a, 222a may also be connected so as to be able to rotate as a whole by a key structure or the like. When a spline structure is used, one of the motor shaft side connection parts 106a, 206a and the input shaft side connection parts 122a, 222a is provided with a male spline portion, and the other is provided with a female spline portion that meshes with the male spline portion. In this embodiment, the motor shaft side connection parts 106a, 206a are provided with female spline portions, and the input shaft side connection parts 122a, 222a are provided with male spline portions.

[0034] The motor shaft side connection portions 106a, 206a of the motor shafts 106, 206 and the input shaft side connection portions 122a, 222a of the input shafts 122, 222 are connected by a float connection so that they can rotate as a single unit. Here, a float connection means a connection that allows torque to be transmitted between the motor shafts 106, 206 and the input shafts 122, 222, and also allows relative movement in a direction parallel to the plane perpendicular to the axial direction (hereinafter referred to as the orthoaxial direction). This relative movement between the motor shafts 106, 206 and the input shafts 122, 222 is permitted when at least the centerlines of both are aligned. To realize the float connection, radial gaps 152, 252 are provided between the motor shafts 106, 206 and the input shafts 122, 222. The radial gaps 152, 252 are provided between the radially opposing portions of the motor shafts 106, 206 and the input shafts 122, 222. The radial gaps 152 and 252 allow for radial relative movement of the input shafts 122 and 222 relative to the motor shafts 106 and 206 when the centerlines of the motor shafts 106 and 206 and the input shafts 122 and 222 coincide, assuming that all members other than the input shafts 122 and 222 are omitted from the reduction gears 104 and 204. The radial gaps 152 and 252 are provided throughout the entire axial range where the motor shafts 106 and 206 and the input shafts 122 and 222 overlap radially. For example, the radial gaps 152 and 252 are provided between the motor shaft side connection parts 106a and 206a and the input shaft side connection parts 122a and 222a.

[0035] Shaft sealing members 154 and 254 are positioned between the motor shafts 106 and 206 and the input shafts 122 and 222. The shaft sealing members 154 and 254 seal the space within the hollow portions 148a and 248a of one of the shafts 148 and 248. In this embodiment, the shaft sealing members 154 and 254 are O-rings. This specific example is not particularly limited, and other types such as V-rings and rubber packings may also be used.

[0036] The motor shafts 106 and 206 have motor shaft side sealing surfaces 106b and 206b that contact the shaft sealing members 154 and 254. The motor shaft side sealing surfaces 106b and 206b are located on the inlet side of the hollow sections 148a and 248a, rather than on the motor shaft side connection portions 106a and 206a. The input shafts 122 and 222 have input shaft side sealing surfaces 122b and 222b that contact the shaft sealing members 154 and 254. The input shaft side sealing surfaces 122b and 222b are located on the inlet side of the hollow sections 148a and 248a, rather than on the input shaft side connection portions 122a and 222a. The shaft sealing members 154 and 254 are positioned between the motor shaft side sealing surfaces 106b and 206b and the input shaft side sealing surfaces 122b and 222b. The shaft sealing members 154 and 254 are mounted in mounting grooves 156 and 256 provided on either the motor shaft side sealing surface 106b and 206b or the input shaft side sealing surface 122b and 222b. In this embodiment, the mounting grooves 156 and 256 are provided on the input shaft side sealing surface 122b and 222b.

[0037] The motor casings 112, 212 and the gearbox casings 130, 230 are detachably connected. In this embodiment, the motor casings 112, 212 and the gearbox casings 130, 230 are connected via adapters 132, 232, but they may also be connected without adapters 132, 232. In this embodiment, the motor casings 112, 212 and the gearbox casings 130, 230 are detachably connected by fastening the load-side motor covers 118, 218 of the motor casings 112, 212 and the adapters 132, 232 with adapter bolts B2. When the motor casings 112, 212 and the gearbox casings 130, 230 are connected, the motor shafts 106, 206 and the input shafts 122, 222 are connected so as to be able to rotate together by the float connection described above. When the motor casings 112, 212 and the gearbox casings 130, 230 are separated, the internal spaces 128, 228 of the gearbox remain sealed by the gearbox sealing members 146, 246.

[0038] An example of the assembly process for gear motors 100 and 200 is described below. When assembling gear motors 100 and 200, the motors 102 and 202 and the reduction gears 104 and 204 are pre-assembled as semi-finished products. At this time, the sealing process of filling the internal spaces 128 and 228 of the reduction gears with lubricant is also completed in advance. This sealing process is carried out by supplying lubricant to the internal spaces 128 and 228 of the reduction gears through lubrication holes (not shown) provided in the reduction gear casings 130 and 230, and then closing the lubrication holes with plugs (not shown).

[0039] Next, the final step is performed to obtain gear motors 100 and 200 by combining motors 102 and 202 with reduction gears 104 and 204. At this time, motors 102 and 202 and reduction gears 104 and 204 are moved relative to each other, and the other shafts 150 and 250 are inserted into the hollow portions 148a and 248a of the aforementioned one shaft 148 and 248, thereby connecting motor shafts 106 and 206 with input shafts 122 and 222. At this time, motors 102 and 202 and reduction gears 104 and 204 are moved relative to each other until the parts of motor shafts 106 and 206 and reduction gears 104 and 204 that face each other in the axial direction, other than the parts of motor shafts 106 and 206 and input shafts 122 and 222, are brought into contact, thereby completing the connection between motor shafts 106 and 206 and input shafts 122 and 222. In this embodiment, the axially opposed points of the motors 102, 202 and the gearboxes 104, 204 are the motor casings 112, 212 of the motors 102, 202 and the adapters 132, 232 of the gearboxes 104, 204. During the process of moving the motors 102, 202 and the gearboxes 104, 204 relative to each other, the cover-side fitting surfaces 118a, 218a of the load-side motor covers 118, 218 and the adapter-side fitting surfaces 132a, 232a of the adapters 132, 232 are fitted together in a spigot configuration to position them radially. After this, in this embodiment, the final step of obtaining the gear motors 100, 200 is completed by fastening the adapters 132, 232 and the load-side motor covers 118, 218 with adapter bolts B2.

[0040] Refer to Figure 4. Next, the second gear motor 200 will be described. In describing the second gear motor 200, many of the components of the second gear motor 200 that are common with the first gear motor 100 will only be given the same last two digits as their corresponding symbols, and their detailed explanations will be omitted.

[0041] The second motor 202 includes a second motor shaft 206, a second stator 208, a second rotor 210, a second motor casing 212, and a second motor shaft bearing 214, similar to the components of the first motor 102. The second motor 202 is common with the first motor 102. In this specification, "common" for the two motors (here the first and second motors 102 and 202) means that although they are separate objects, the shapes, dimensions, materials, and numbers of the various components of the two motors are the same. Here, the same shapes, dimensions, and materials mean that they are the same in design, and slight differences due to errors such as manufacturing errors are of course allowed. For example, the first motor shaft 106 and the second motor shaft 206 will have the same shape, dimensions, and materials.

[0042] The second speed reducer 204 includes a second input shaft 222, a second speed reduction mechanism 224, a second output member 226, a second speed reducer casing 230, a second adapter 232, a second input shaft bearing 234, etc., similar to the components of the first speed reducer 104.

[0043] The second input shaft 222 is rotatably supported via bearings with respect to the second speed reducer casing 230 and the second adapter 232, similar to the first input shaft 122. Specifically, the second input shaft 222 is supported with respect to the second adapter 232 via a second anti-load-side input shaft bearing 234B. Also, the second input shaft 222 is supported with respect to the second speed reducer casing 230 via a second load-side input shaft bearing 234A.

[0044] The second speed reducer 204 includes a second speed reduction mechanism 224 that is different from the first speed reduction mechanism 124. Here, "different" means either (1) the types of the speed reduction mechanisms are different between the first speed reduction mechanism 124 and the second speed reduction mechanism 224, or (2) the load capacities (maximum allowable torques) are different between the first speed reduction mechanism 124 and the second speed reduction mechanism 224. Here, an example of (1) will be described.

[0045] The first reduction mechanism 124 of this embodiment is equipped with a center crank type eccentric oscillating reduction mechanism. In contrast, the second reduction mechanism 224 of this embodiment is equipped with a bevel gear mechanism 224a and a parallel shaft gear mechanism 224b. The bevel gear mechanism 224a is equipped with a bevel pinion 224c provided on the second input shaft 222 and a bevel gear 224d provided on the intermediate shaft 236 that meshes with the bevel pinion 224c. The parallel shaft gear mechanism 224b is equipped with an intermediate pinion 224e provided on the intermediate shaft 236 and an output gear 224f provided on the second output member 226 that meshes with the intermediate pinion 224e. The intermediate shaft 236 is rotatably supported in the second reduction gear casing 230 via a bearing (not shown). The rotation of the second input shaft 222 is transmitted to the second output member 226 via the second reduction mechanism 224. In this process, the second reduction mechanism 224 transmits a rotation reduced from that of the second input shaft 222 to the second output member 226. The second output member 226 outputs the reduced rotation transmitted from the second reduction mechanism 224 to the driven machine. The second output member 226 is rotatably supported in the second reduction gear casing 230 via bearings (not shown).

[0046] Unlike the internal space 128 of the first reducer, the internal space 228 of the second reducer houses the components of the bevel gear mechanism 224a and the parallel shaft gear mechanism 224b. One second reducer seal member 246 is positioned between the second adapter 232 and the second input shaft 222, similar to the first reducer seal member 146. Another second reducer seal member 246, unlike the other first reducer seal member 146, is positioned between the second reducer casing 230 and the second output member 226, although it is not shown. The second mounting portion (not shown) of the second reducer casing 230 is provided on the side surface of the second output member 226 facing the axial direction (perpendicular to the plane of the paper in Figure 4), unlike the first mounting portion 130a of the first reducer casing 130.

[0047] Unlike the first load-side input shaft bearing 134A, the second load-side input shaft bearing 234A is positioned between the second reduction gear casing 230 and the second input shaft 222. The second non-load-side input shaft bearing 234B is positioned between the second adapter 232 and the second input shaft 222, similar to the first non-load-side input shaft bearing 134B.

[0048] Refer to FIG. 5. The second motor shaft side connection portion 206a of the second motor shaft 206 and the second input shaft side connection portion 222a of the second input shaft 222 are connected so as to be integrally rotatable by a floating connection, similar to the first gear motor 100. The second motor shaft side connection portion 206a and the second input shaft side connection portion 222a of this embodiment are also connected so as to be integrally rotatable by a spline structure, similar to the first gear motor 100.

[0049] Next, the main features common to the first reduction gear 104 and the second reduction gear 204 will be described.

[0050] The shapes of the input shaft side connection portions 122a and 222a of the first and second input shafts 122 and 222 are the same. Here, the fact that the shapes of the input shaft side connection portions 122a and 222a are the same means that the shapes of the portions contributing to the integrally rotatable connection of the first and second input shafts 122 and 222 to the motor shafts 106 and 206, including their dimensions, are the same. Therefore, in each of the first and second input shafts 122 and 222, the shapes of the portions other than the input shaft side connection portions 122a and 222a (for example, the portions closer to the base end than the input shaft side connection portions 122a and 222a) do not have to be the same. In this embodiment, it means that the shapes of the male spline portions provided in the input shaft side connection portions 122a and 222a of the first and second input shafts 122 and 222 are the same.

[0051] The shapes of the adapter side fitting surfaces 132a and 232a of the first and second adapters 132 and 232 are the same. Here, the fact that the shapes of the adapter side fitting surfaces 132a and 232a are the same means that the shapes of the portions contributing to the inro fitting of the first and second adapters 132 and 232 to the load side motor covers 118 and 218, including their dimensions, are the same. Therefore, in each of the adapters 132 and 232, the shapes of the portions other than the adapter side fitting surfaces 132a and 232a do not have to be the same. In this embodiment, it means that the shapes of the outer peripheral surfaces constituting the adapter side fitting surfaces 132a and 232a of the first and second adapters 132 and 232 are the same.

[0052] The effects regarding the series of the gear motors 100 and 200 described above will be explained.

[0053] The first and second input shafts 122 and 222 are connected to the first and second motor shafts 106 and 206, respectively, by float connections, allowing them to rotate as a single unit. Therefore, it is easier to connect the first and second input shafts 122 and 222 to the first and second motor shafts 106 and 206, respectively, compared to the case where the input shafts 122 and 222 are connected to the motor shafts 106 and 206 by press-fitting. This is because when the two are connected by inserting the other shaft 150 and 250 into the hollow portions 148a and 248a of one shaft 148 and 248, the insertion resistance is smaller compared to the case where the input shafts 122 and 222 are connected to the motor shafts 106 and 206 by press-fitting. Consequently, the workability during the assembly of the first and second gear motors 100 and 200 is improved.

[0054] Furthermore, compared to the case where the input shafts 122 and 222 are connected to the motor shafts 106 and 206 by press-fitting as described above, it becomes easier to disconnect the first and second input shafts 122 and 222 from the first and second motor shafts 106 and 206, respectively. This is because when disconnecting the two by pulling out the other shaft 150 and 250 from the hollow portions 148a and 248a of one shaft 148 and 248, the pulling resistance is smaller compared to the case where the input shafts 122 and 222 are connected to the motor shafts 106 and 206 by press-fitting. Therefore, the workability during the disassembly of the first and second gear motors 100 and 200 is also improved.

[0055] Furthermore, the float connection allows for radial misalignment between the motor shafts 106, 206 and the input shafts 122, 222. Therefore, compared to the case where the motor shafts 106, 206 and the input shafts 122, 222 are connected by press-fitting, it becomes easier to reduce the radial load transmitted from the input shafts 122, 222 to the motor shafts 106, 206 due to the reduction mechanisms 124, 224, which is advantageous in reducing the load-bearing capacity required of the motors 102, 202. In particular, when motors 102, 202 are common to multiple types of reduction gears 104, 204, it becomes possible to design the motors 102, 202 while suppressing the influence of radial loads caused by various reduction mechanisms 124, 242, which is advantageous in expanding the types of motors 102, 202 that can be applied.

[0056] Furthermore, the first motor 102 and the second motor 202 are common to the first and second gear motors 100 and 200 belonging to the series. Therefore, compared to designing separate motors for the first and second gear motors 100 and 200, the number of parts that need to be managed across the entire series can be reduced, which is advantageous in reducing overall manufacturing and management costs for the series.

[0057] The first and second reduction gears 104 and 204 are equipped with at least two first and second input shaft bearings 134 and 234 that receive the moment load acting on the first and second input shafts 122 and 222. Therefore, by having the two first and second input shaft bearings 134 and 234 receive the moment load and radial load transmitted to the first and second input shafts 122 and 222 due to the first and second reduction gears 124 and 224, the various loads (radial load, moment load) transmitted from the first and second input shafts 122 and 222 to the first and second motor shafts 106 and 206 can be greatly reduced. As a result, the load-bearing capacity required of the first and second motors 102 and 202 can be reduced, which is advantageous for reducing the cost of the first and second motors 102 and 202.

[0058] The shapes of the input shaft side connection parts 122a and 222a of the first and second input shafts 122 and 222 are the same. Therefore, compared to designing input shaft side connection parts 122a and 222a with dedicated shapes for the first and second input shafts 122 and 222 respectively, the effort required for their design can be reduced.

[0059] If the load-side motor covers 118 and 218 are omitted and the load-side motor shaft bearings 114A and 214A are used instead, the load-side motor shaft bearings 114A and 214A will be incorporated into the reduction gears 104 and 204. In this case, the assembly of the load-side motor shaft bearings 114A and 214A to the motor shafts 106 and 206 will be required extra work when connecting the motor shafts 106 and 206 to the input shafts 122 and 222. In this configuration, the common first and second motors 102 and 202 are equipped with load-side motor covers 118 and 218. Therefore, in the semi-finished first and second motors 102 and 202, the motor shafts 106 and 206 can be supported by the load-side motor covers 118 and 218 via the load-side motor shaft bearings 114A and 214A. This eliminates the need to assemble the load-side motor shaft bearings 114A and 214A onto the motor shafts 106 and 206 when connecting the motor shafts 106 and 206 to the input shafts 122 and 222.

[0060] Furthermore, if the adapters 132 and 232 are omitted and the non-load side input shaft bearings 134B and 234B are used, the non-load side input shaft bearings 134B and 234B will be incorporated into the motors 102 and 202. In this case, when connecting the motor shafts 106 and 206 to the input shafts 122 and 222, the assembly work of the non-load side input shaft bearings 134B and 234B to the input shafts 122 and 222 will be required as an extra step. In this regard, the first and second reduction gears 104 and 204 of this embodiment are each equipped with first and second adapters 132 and 232, which are connected to the first and second reduction gear casings 130 and 230, respectively, and to the load side motor covers 118 and 218. Therefore, in the first and second reduction gears 104 and 204 as semi-finished products, the input shafts 122 and 222 can be supported by the first and second adapters 132 and 232, respectively, via the non-load side input shaft bearings 134B and 234B. This eliminates the need to assemble the non-load side input shaft bearings 134B and 234B to the input shafts 122 and 222 when connecting the motor shafts 106 and 206 to the input shafts 122 and 222.

[0061] As a result, in the final process of obtaining gear motors 100 and 200 by combining the semi-finished motors 102 and 202 and the reduction gears 104 and 204, respectively, it is possible to reduce as much extra work as possible other than the connection work between the motor shafts 106 and 206 and the input shafts 122 and 222. Consequently, the workload in the final process of obtaining gear motors 100 and 200 can be reduced.

[0062] Furthermore, in the semi-finished first and second reduction gears 104 and 204, reduction gear sealing members 146 and 246 can be placed between the first and second adapters 132 and 232, respectively, and the first and second input shafts 122 and 222, respectively. This allows the sealing work of sealing lubricant into the internal spaces 128 and 228 of each reduction gear 104 and 204 to be completed before the final step of obtaining the gear motors 100 and 200. Therefore, the workload in the final step of obtaining the gear motors 100 and 200 can be further reduced.

[0063] The shapes of the adapter-side mating surfaces 132a and 232a of the first and second adapters 132 and 232 are the same. Therefore, compared to designing adapter-side mating surfaces 132a and 232a with shapes specific to each of the first and second adapters 132 and 232, the effort required for their design can be reduced.

[0064] Next, we will describe other features of the gear motor series 100 and 200. Here, we will describe the features of adapters 132 and 232. Below, we will describe the features common to the first and second gear motors 100 and 200. Here, we will describe the features common to these with reference to Figures 1 and 2.

[0065] The motor frames 116 and 216 each have four side portions 116a and 216a facing each of the four sides, a plurality of fin portions 116b and 216b protruding from each of the four side portions 116a and 216a, and frame-side protrusions 116c and 216c that protrude radially outward from the outer circumference of the motor frames 116 and 216.

[0066] The motor frames 116, 216 and the load-side motor covers 118, 218 are fastened together by a plurality of motor bolts B3. The plurality of motor bolts B3 are arranged on a reference pitch circle PCa when viewed from the axial direction. In this embodiment, the plurality of motor bolts B3 are arranged at equal angular intervals in the circumferential direction on this reference pitch circle PCa when viewed from the axial direction. This pitch circle is the circle formed by connecting the centers of the bolt holes 158, 258 through which the plurality of motor bolts B3 are inserted when viewed from the axial direction. The motor bolts B3 are located at circumferential positions between adjacent side portions 116a, 216a when viewed from the axial direction. It can also be said that the motor bolts B3 are located at circumferential positions between fin portions 116b, 216b belonging to adjacent side portions 116a, 216a. The plurality of motor bolts B3 may be arranged on different pitch circles. In this case, the pitch circle that is radially outermost is defined as the reference pitch circle PCa.

[0067] The shaft portion of the motor bolt B3 is inserted from the non-load side into bolt holes 158 and 258 provided in the motor frames 116 and 216 and the load-side motor covers 118 and 218, respectively. In this embodiment, the bolt holes 158 and 258 of the load-side motor covers 118 and 218 are provided with female threads, and the male thread portion of the motor bolt B3 is screwed into these female threads to fasten the motor frames 116 and 216 to the load-side motor covers 118 and 218. In this embodiment, the bolt holes 158 and 258 of the motor frames 116 and 216 are provided in the frame-side protrusions 116c and 216c.

[0068] The adapters 132 and 232 and the load-side motor covers 118 and 218 are fastened to the load-side motor covers 118 and 218 from the non-load side using adapter bolts B2. This means that when fastening using the adapter bolts B2, working spaces 160 and 260 for handling the adapter bolts B2 are provided on the non-load side relative to the load-side motor covers 118 and 218. In this way, the adapters 132 and 232 and the load-side motor covers 118 and 218 are connected. Figure 1 shows a portion of the working spaces 160 and 260.

[0069] The shaft of the adapter bolt B2 is inserted from the non-load side into bolt holes 162 and 262 provided in the adapters 132 and 232 and the load-side motor covers 118 and 218, respectively. The bolt holes 162 and 262 of the load-side motor covers 118 and 218 are provided in flange portions 162a and 262a that protrude radially outward on the outer circumference of the load-side motor covers 118 and 218. In this embodiment, female threads are provided in the bolt holes 162 and 262 of the adapters 132 and 232, and the male threads of the adapter bolt B2 are screwed into these female threads to fasten the adapters 132 and 232 to the load-side motor covers 118 and 218. Alternatively, nuts may be placed on the load side of the adapters 132 and 232, and the male threads of the adapter bolt B2 may be screwed into these nuts to fasten the adapters 132 and 232 to the load-side motor covers 118 and 218. The number and position of adapter bolts B2 used to fasten the first and second adapters 132 and 232 to the first and second load-side motor covers 118 and 218 are the same.

[0070] The adapter bolts B2 are positioned radially outward from the aforementioned reference pitch circle PCa when viewed from the axial direction. In this embodiment, multiple adapter bolts B2 are arranged with spacing in the circumferential direction. Multiple adapter bolts B2 in this embodiment are arranged on a pitch circle PCb with a larger diameter than the reference pitch circle PCa. This pitch circle is the circle formed by connecting the centers of the bolt holes 162 and 262 through which the multiple adapter bolts B2 are inserted when viewed from the axial direction. The adapter bolts B2 may be provided in a position that overlaps radially outward with respect to the motor bolts B3 when viewed from the axial direction. At least a portion of the adapter bolts B2 may be provided in the same axial position as at least a portion of the motor bolts B3. At least a portion of the adapter bolts B2 may be provided in the same axial position as at least a portion of the bolt holes 132b and 232b through which the bolts B1 are inserted in the adapters 132 and 232. At least a portion of the adapter bolt B2 may be located in the same axial position as at least a portion of the bolt holes 158 and 258 of the load-side motor covers 118 and 218 through which the motor bolt B3 is inserted.

[0071] The effects of the above features will now be explained. Let's consider the case where the first and second adapters 132 and 232, respectively, are fastened to the load-side motor covers 118 and 218 from the load side using adapter bolts B2. In this case, it is necessary to secure working space on the load side relative to each adapter 132 and 232. However, in this case, depending on the structure of the reducer casings 130 and 230, the mounting portion 130a for attaching to the mounting part of the driven machine may be on the load side relative to each adapter 132 and 232, making it difficult to secure working space. Also, in order to avoid interference with the mounting portion 130a of the reducer casings 130 and 230, as shown in Figure 6, it is possible to move the fastening points of each adapter 132 and 232 with adapter bolts B2 away from the reducer casings 130 and 230 to the non-load side, thereby securing working space S on the load side relative to the fastening points. However, this would lead to an increase in the axial dimensions of each gear motor 100, 200.

[0072] (A) In this respect, according to this embodiment, the adapters 132 and 232 and the load-side motor covers 118 and 218 are fastened together from the non-load side using adapter bolts B2. Therefore, working spaces 160 and 260 can be secured regardless of the structure of the gearbox casings 130 and 230 on the load side of the adapters 132 and 232, and these working spaces 160 and 260 can be used to fasten the adapters 132 and 232 and the load-side motor covers 118 and 218. This is advantageous in terms of expanding the types of first and second gearboxes 104 and 204 that can be selected when standardizing the motors 102 and 202 between the first and second gearboxes 104 and 204. In addition, since the fastening points using adapter bolts B2 do not need to be moved far away from the gearbox casings 130 and 230 on the non-load side, it is advantageous in terms of miniaturizing the axial dimensions of the gear motors 100 and 200. In relation to the effects described here, it is sufficient that the first adapter 132 and the first load-side motor cover 118 are fastened together from the non-load side using adapter bolts B2.

[0073] The motor frames 116 and 216 typically have fin sections 116b and 216b located on or radially inward from the reference pitch circle PCa, making it difficult to secure working space 160 and 260 for the adapter bolts B2. As a countermeasure, it is conceivable to provide relief sections in the load-side motor covers 118 and 218 to avoid interference with the adapter bolts B2. However, in this case, it is necessary to increase the axial dimensions of the load-side motor covers 118 and 218, which in turn leads to an increase in the axial dimensions of the gear motors 100 and 200.

[0074] In this respect, according to this embodiment, the adapter bolts B2 that fasten the first and second adapters 132 and 232 to the first and second load-side motor covers 118 and 218 are arranged radially outward from the reference pitch circle PCa. Therefore, it becomes easier to secure working spaces 160 and 260 for the adapter bolts B2 in a position that does not interfere with a part of the motor frame 116 and 216. This is advantageous in expanding the types of motors 102 and 202 that can be used when motors 102 and 202 are common to multiple types of reduction gears 104 and 204. In addition, since it is not necessary to provide relief parts in the load-side motor covers 118 and 218 to avoid interference with the adapter bolts B2, it is advantageous in reducing the axial dimensions of the gear motors 100 and 200. In relation to the effects described here, it is sufficient that at least the adapter bolts B2 that fasten the first adapter 132 to the first load-side motor cover 118 are arranged radially outward from the reference pitch circle PCa.

[0075] Next, other features of the gear motors 100 and 200 will be described. Refer to Figures 3 and 5. We will consider the clearance amount Rm of the radial gaps 152 and 252 mentioned above. This clearance amount Rm of the radial gaps 152 and 252 refers to the maximum radial movement of the input shafts 122 and 222 relative to the motor shafts 106 and 206 from a reference position where the central axes of the input shafts 122 and 222 and the motor shafts 106 and 206 are aligned. Figures 3, 5, and 7 show the state where the input shafts 122 and 222 and the motor shafts 106 and 206 are in the reference position. If the relative position of the input shafts 122 and 222 and the motor shafts 106 and 206 in the circumferential direction can be adjusted, this maximum movement amount will be the maximum movement amount when the relative position in the circumferential direction is at which the radial movement amount is greatest. We will consider the case where the motor shafts 106 and 206 and the input shafts 122 and 222 are connected by a spline structure as in this embodiment. In this case, the relative position in the circumferential direction where the amount of radial movement is greatest may be the position where the circumferential center position P1 of the tooth root of the female spline portion and the circumferential position P2 of the tooth tip of the male spline portion coincide (see Figure 7). Figure 7 schematically shows the female spline portions of the motor shaft side connection portions 106a and 206a of the motor shafts 106 and 206, and the male spline portions of the input shaft side connection portions 122a and 222a of the input shafts 122 and 222.

[0076] Refer to Figures 1 and 4. In Figures 1 and 4, arrows are used to indicate parts of the load transmission paths Pa and Pb, which will be described later. We will examine the total amount Ra of radial internal clearance of the bearings on the load transmission path Pa between the adapters 132 and 232 and the input shafts 122 and 222, passing through the non-load side input shaft bearings 134B and 234B. In this embodiment, only the non-load side input shaft bearings 134B and 234B exist on this load transmission path Pa for both the first and second gear motors 100 and 200. Therefore, the total amount Ra of radial internal clearance for the first and second gear motors 100 and 200 refers only to the radial internal clearance of the non-load side input shaft bearings 134B and 234B. This radial internal clearance refers to the maximum amount of movement when one of the outer or inner rings of the bearing is fixed and the other is moved radially.

[0077] We will examine the total amount Rb of radial internal clearance of bearings on the load transmission path Pb between the reduction gear casings 130, 230 and the input shafts 122, 222, via the load-side input shaft bearings 134A, 234A. In this embodiment, the first gear motor 100 has two load transmission paths Pb: load transmission path Pb-1 via the first load-side input shaft bearing 134A and the non-load-side main bearing 136, and load transmission path Pb-2 via the first load-side input shaft bearing 134A and the load-side main bearing 136. The total amount Rb-1 of radial internal clearance of bearings on this load transmission path Pb-1 is the sum of the radial internal clearances of the first load-side input shaft bearing 134A and the non-load-side main bearing 136. Furthermore, the total radial internal clearance Rb-2 of the bearings on the load transmission path Pb-2 is the sum of the radial internal clearances of the first load-side input shaft bearing 134A and the load-side main bearing 136. In the second gear motor 200, only the second load-side input shaft bearing 234A is present on this load transmission path Pb. Therefore, the total radial internal clearance Rb of the second gear motor 200 refers only to the radial internal clearance of the second load-side input shaft bearing 234A.

[0078] In this case, the total amount Ra, Rb of the radial internal gaps of the bearings on at least one load transmission path Pa, Pb between the reduction gear casing 130, 230 or adapter 132, 232 and the input shafts 122, 222 may be smaller than the gap amount Rm of the radial gaps 152, 252. For example, in the case of the first gear motor 100, the total amount Ra of the radial internal gaps on the load transmission path Pa via the first non-load side input shaft bearing 134B may be smaller than the gap amount Rm of the first radial gap 152. Also, the total amount Rb of the radial internal gaps on the load transmission paths Pb-1, Pb-2 via the first load side input shaft bearing 134A may be smaller than the gap amount Rm of the first radial gap 152. Furthermore, in the case of the second gear motor 200, the total amount Ra of radial internal gaps on the load transmission path Pa via the second non-load side input shaft bearing 234B may be smaller than the gap amount Rm of the second radial gap 252. Also, the total amount Rb of radial internal gaps on the load transmission path Pb via the second load side input shaft bearing 234A may be smaller than the gap amount Rm of the second radial gap 252.

[0079] This means that even if the input shafts 122 and 222 are radially misaligned from their reference positions within the range of the radial internal clearance of the bearings on each load transmission path Pa and Pb, a radial clearance of 152 and 252 can be maintained between the motor shafts 106 and 206 and the input shafts 122 and 222, thereby preventing the transmission of load from the input shafts 122 and 222 to the motor shafts 106 and 206. Therefore, the radial load transmitted from the input shafts 122 and 222 to the motor shafts 106 and 206 due to the reduction mechanism 124 and 224 can be greatly reduced, which is even more advantageous in reducing the load-bearing capacity required of the motors 102 and 202. In this embodiment, the same effect can be obtained in each of the first and second gear motors 100 and 200.

[0080] From this perspective, it is sufficient that the total amount Ra, Rb of the radial internal clearances of the bearings on at least one load transmission path Pa, Pb between the reduction gear casings 130, 230 or adapters 132, 232 and the input shafts 122, 222 is smaller than the clearance amount Rm of the radial clearances 152, 252. Furthermore, it is sufficient that the conditions described here are met in at least the first gear motor 100, and it is not essential that they are met in both the first and second gear motors 100 and 200.

[0081] The motors 102 and 202 are equipped with motor shaft restricting structures 164 and 264 that restrict the axial movement of the motor shafts 106 and 206 toward the load side relative to the motor casings 112 and 212. The motor shaft restricting structures 164 and 264 in this embodiment include outer motor shaft restricting parts 164a and 264a provided on the motor casings 112 and 212, and inner motor shaft restricting parts 164b and 264b provided on the motor shafts 106 and 206.

[0082] The outer motor shaft restrictors 164a and 264a restrict the axial movement of the load-side motor shaft bearings 114A and 214A toward the load side by directly or indirectly contacting them from the non-load side. The outer motor shaft restrictors 164a and 264a are formed by stepped portions provided on the motor casings 112 and 212, but may also be formed by retaining rings or the like provided on the motor casings 112 and 212. "Indirect contact" here means that one of the two objects being referred to (in this case, the outer motor shaft restrictors 164a and 264a) is contacted by the other object (in this case, the load-side motor shaft bearings 114A and 214A) via another component. In other words, there may be other components between the outer motor shaft restrictors 164a and 264a and the load-side motor shaft bearings 114A and 214A.

[0083] The inner motor shaft restricting portions 164b and 264b restrict the axial movement of the motor shafts 106 and 206 toward the load side by directly or indirectly contacting the load-side motor shaft bearings 114A and 214A from the non-load side. The inner motor shaft restricting portions 164b and 264b are formed by stepped portions provided on the motor shafts 106 and 206, but may also be formed by retaining rings or the like provided on the motor shafts 106 and 206.

[0084] The motor shaft restricting structures 164 and 264 restrict the axial movement of the motor shafts 106 and 206 toward the load side relative to the motor casings 112 and 212 via the load-side motor shaft bearings 114A and 214A, through the outer motor shaft restricting sections 164a and 264a and the inner motor shaft restricting sections 164b and 264b.

[0085] We examine the motor shaft restriction position Pc, where the movement of the motor shafts 106 and 206 toward the load side is restricted by the motor shaft restriction structures 164 and 264. When the motor shafts 106 and 206 are in the motor shaft restriction position Pc, the axial gap between multiple members between the motor casings 112 and 212 and the motor shafts 106 and 206, via the motor shaft restriction structures 164 and 264, becomes zero. This "axial gap between multiple members" includes (1) the axial internal gap of the bearings such as the load-side motor shaft bearing 114, which is passed through the motor shaft restriction structures 164 and 264, and (2) the axial gap between the outer motor shaft restriction parts 164a and 264a and the inner motor shaft restriction parts 164b and 264b, respectively, and the load-side motor shaft bearings 114A and 214A. The axial internal gap is the internal gap of the bearing that allows relative axial movement of the outer and inner rings of the bearing. (2) If there are multiple members between each motor shaft restricting part and the load-side motor shaft bearings 114A, 214A, the axial gap between those multiple members is also included. (2) If each motor shaft restricting part is made of a separate member such as a retaining ring, separate from the motor casings 112, 212 and motor shafts 106, 206, the axial gap between that separate member and the motor casings 112, 212 or motor shafts 106, 206 is also included.

[0086] The reducers 104 and 204 are equipped with input shaft restricting structures 166 and 266 that restrict the axial movement of the input shafts 122 and 222 toward the non-load side relative to the adapters 132 and 232. The input shaft restricting structures 166 and 266 in this embodiment include outer input shaft restricting parts 166a and 266a provided on the adapters 132 and 232, and inner input shaft restricting parts 166b and 266b provided on the input shafts 122 and 222.

[0087] The outer input shaft restricting portions 166a and 266a restrict the axial movement of the non-load side input shaft bearings 134B and 234B toward the non-load side by directly or indirectly contacting them from the load side. The outer input shaft restricting portions 166a and 266a are formed by stepped portions provided on the adapters 132 and 232, but may also be formed by retaining rings or the like provided on the adapters 132 and 232. In this embodiment, in both the first and second gear motors 100 and 200, there are no other members between the outer input shaft restricting portions 166a and 266a and the non-load side input shaft bearings 134B and 234B, but other members may be present.

[0088] The inner input shaft restrictors 166b and 266b restrict the axial movement of the input shafts 122 and 222 toward the non-load side by directly or indirectly contacting the non-load side input shaft bearings 134B and 234B from the load side. In the first gear motor 100, the inner input shaft restrictors 166b and 266b are composed of other members such as retaining rings provided on the input shafts 122 and 222, but may also be composed of stepped portions provided on the input shafts 122 and 222. In this embodiment, in the first gear motor 100, a spacer 168, an eccentric portion 138a, and a load side input shaft bearing 134A are present between the inner input shaft restrictors 166b and 266b and the non-load side input shaft bearings 134B and 234B. In the second gear motor 200, the inner input shaft restrictors 166b and 266b are composed of stepped portions provided on the input shafts 122 and 222. In the second gear motor 200, there are no other components between the inner input shaft restricting portions 166b and 266b and the non-load side input shaft bearings 134B and 234B.

[0089] The input shaft restricting structures 166 and 266 restrict the axial movement of the input shafts 122 and 222 toward the non-load side relative to the adapters 132 and 232 via the non-load side input shaft bearings 134B and 234B, through the outer input shaft restricting parts 166a and 266a and the inner input shaft restricting parts 166b and 266b.

[0090] The input shaft restricting structures 166 and 266 may be used instead of the adapters 132 and 232 to restrict the axial movement of the input shafts 122 and 222 toward the non-load side relative to the reduction gear casings 130 and 230. In this case, instead of the adapters 132 and 232, the reduction gear casings 130 and 230 may be provided with outer input shaft restricting sections 166a and 266a that restrict the axial movement of the non-load side input shaft bearings 134B and 234B toward the non-load side.

[0091] We examine the input shaft restriction position Pd, where the movement of the input shafts 122 and 222 toward the non-load side is restricted by the input shaft restriction structures 166 and 266. When the input shafts 122 and 222 are in the input shaft restriction position Pd, the axial gap between the multiple members between the input shafts 122 and 222 and the reduction gear casings 130 and 230 or the adapters 132 and 232 via the input shaft restriction structures 166 and 266 becomes zero. This "axial gap between multiple members" includes (1) the axial internal gap of the bearings such as the input shaft bearings 134 and 234 that pass through the input shaft restriction structures 166 and 266, and (2) the axial gap between the outer input shaft restriction parts 166a and 266a and the inner input shaft restriction parts 166b and 266b, respectively, and the non-load side input shaft bearings 134B and 234B. (2) If there are multiple members between each input shaft restricting section and the non-load side input shaft bearings 134B, 234B, the axial gap between those multiple members is also included. (2) If each input shaft restricting section is made of a separate member from the reducer casings 130, 230, adapters 132, 232, input shafts 122, 222, such as a retaining ring, the axial gap between that separate member and the reducer casings 130, 230, adapters 132, 232 or input shafts 122, 222 is also included.

[0092] The input shafts 122 and 222 are movable in the axial direction due to the axial gaps between multiple members constituting the reduction gears 104 and 204. The multiple members referred to here are, for example, the multiple members constituting the input shaft restricting structures 166 and 266 described above. In addition, in the case of the first gear motor 100, this also includes the axial gap between the first load-side input shaft bearing 134A and the first output member 126.

[0093] Axial gaps 170 and 270 are provided between the motor shafts 106 and 206 and the input shafts 122 and 222 (see Figures 3 and 5). In Figures 3 and 5, parts of the axial gaps 170 and 270 are enclosed by dashed lines. The axial gaps 170 and 270 allow relative movement of the input shafts 122 and 222 toward the non-load side with respect to the motor shafts 106 and 206, assuming that all members other than the input shafts 122 and 222 are omitted from the reduction gears 104 and 204.

[0094] The axial gaps 170 and 270 exist in a range greater than zero when the motor shafts 106 and 206 are at the motor shaft restriction position Pc, where movement toward the load side is restricted, and the input shafts 122 and 222 are at the input shaft restriction position Pd, where movement toward the opposite load side is restricted. The axial gaps 170 and 270 always exist when the input shafts 122 and 222 are within the range of axial movement due to the axial gaps between the multiple members constituting the reduction gears 104 and 204. As a result, even if the input shafts 122 and 222 are misaligned in the axial direction within the range of axial movement due to the axial gaps, the load is not transmitted from the input shafts 122 and 222 to the motor shafts 106 and 206. Consequently, the axial load transmitted from the input shafts 122 and 222 to the motor shafts 106 and 206 due to the reduction gears 124 and 224 can be greatly reduced, which is advantageous in reducing the load-bearing capacity required of the motors 102 and 202.

[0095] In this embodiment, the same effect can be obtained in both the first and second gear motors 100 and 200. This makes it possible to design the motors 102 and 202 without being affected by the axial loads caused by each reduction mechanism 124 and 224 when using motors 102 and 202 in common with multiple types of reduction gears 104 and 204, which is advantageous in expanding the types of motors 102 and 202 that can be applied. The conditions described here only need to be met in the first gear motor 100, and it is not necessary to meet them in both the first and second gear motors 100 and 200.

[0096] (Second Embodiment) Refer to Figure 8. Figure 8 schematically shows various gear motors 1000 to 4000. Next, the series of gear motors of the second embodiment will be described. The series of gear motors comprises a first subseries S1 of gear motors and a second subseries S2 of gear motors. The first subseries S1 comprises a first type gear motor 1000 and a second type gear motor 2000. The first type gear motor 1000 comprises a first type motor 1002 and a first type reducer 1004. The second type gear motor 2000 comprises a second type motor 2002 and a second type reducer 2004. The second subseries S2 comprises a third type gear motor 3000 and a fourth type gear motor 4000. The third type gear motor 3000 comprises a third type motor 3002 and a third type reducer 3004. The fourth-type gear motor 4000 comprises a fourth-type motor 4002 and a fourth-type reducer 4004. Here, "first-type" to "fourth-type" are terms used to distinguish multiple components, similar to "first-type" and "second-type."

[0097] The Type 1 to Type 4 gear motors 1000 to 4000 share many components with the aforementioned Type 1 gear motor 100. The components shared with the Type 1 gear motor 100 are designated with the same last two digits and distinguished by the thousands digit. The Type 1 gear motor 1000 is designated with a number in the 1000s, the Type 2 gear motor 2000 with a number in the 2000s, the Type 3 gear motor 3000 with a number in the 3000s, and the Type 4 gear motor 4000 with a number in the 4000s.

[0098] Type 1 motor 1002 and Type 2 motor 2002 are common to each other. Type 3 motor 3002 and Type 4 motor 4002 are common to each other. The definitions of "Type 1 motor 1002 and Type 2 motor 2002 are common to each other" and "Type 3 motor 3002 and Type 4 motor 4002" are as described above.

[0099] The various motors 1002, 2002, 3002, and 4002 are equipped with motor casings 1012, 2012, 3012, and 4012, which include load-side motor covers 1018, 2018, 3018, and 4018. The motor casings 1012 and 2012 of the first and second type motors 1002 and 2002 are larger than the motor casings 3012 and 4012 of the third and fourth type motors 3002 and 4002. Here, the size of the motor casings 1012 and 2012 refers to the size of the axial or radial dimensions of the motor casings 1012 and 2012. The first and second type motors 1002 and 2002 may have a larger capacity (rated output) than the third and fourth type motors 3002 and 4002.

[0100] Each of the gear reducers 1004, 2004, 3004, and 4004 comprises a gear reducer casing 1030, 2030, 3030, and 4030, and adapters 1032, 2032, 3032, and 4032. Each of the first and second type gear reducers 1004 and 2004 may be equipped with the same type of reduction mechanism (not shown). In this case, the reduction mechanisms of the first and second type gear reducers 1004 and 2004 may have the same reduction ratio. To satisfy this condition, for example, the following first condition may be satisfied, or both of the following first and second conditions may be satisfied. The first condition is that the number of teeth on the external gear and internal gear of the Type 2 reducer 2004 is the same as the number of teeth on the external gear and internal gear of the Type 1 reducer 1004, and at least one of the axial and radial dimensions of the external gear of the Type 2 reducer 2004 is larger than that of the external gear of the Type 1 reducer 1004. The second condition is that the Type 1 reducer 1004 is equipped with a first input shaft 122 and a first reduction mechanism 124 common to the Type 1 reducer 104. Furthermore, the Type 2 reducer 2004 may have a greater transmitted torque than the Type 1 reducer 1004. Also, the Type 3 and Type 4 reducers 3004 and 4004 may each be equipped with the same type of reduction mechanism. In this case, the reduction mechanisms of the Type 3 and Type 4 reducers 3003 and 4004 may each have the same reduction ratio. The reduction mechanism of the third-type reducer 3004 may be the same type as the reduction mechanism of the first-type reducer 1004, and may have a higher reduction ratio. In addition, the reduction mechanism of the third-type reducer 3004 may be the same type as the reduction mechanism of the first-type reducer 1004 and have the same reduction ratio. Here, "same type" means that the type of reduction mechanism (for example, eccentric oscillation type reduction mechanism, deflection mesh type reduction mechanism) is the same.

[0101] The gearbox casing 1030 of the first-class gearbox 1004 is smaller than the gearbox casing 2030 of the second-class gearbox 2004. Similarly, the gearbox casing 3030 of the third-class gearbox 3004 is smaller than the gearbox casing 4030 of the fourth-class gearbox 4004. Here, the size of the gearbox casings refers to the size of the mounting dimensions of the gearbox casing to the driven machine. Here, the mounting dimensions refer to the dimensions of the mounting portion of the gearbox casing to the driven machine.

[0102] The various gear motors 1000, 2000, 3000, and 4000, although not shown in the illustration, have components in common with the first gear motor 100 described above. For example, the various motors 1002, 2002, 3002, and 4004, in addition to the motor casings 1012, 2012, 3012, and 4012 shown in the illustration, have a motor shaft, a stator and rotor, and at least two motor shaft bearings. Similarly, the various reduction gears 1004, 2004, 3004, and 4004, in addition to the reduction gear casings 1030, 2030, 3030, and 4030 shown in the illustration, have an input shaft, a reduction mechanism, an output member, and at least two input shaft bearings. Furthermore, the various gear motors 1000, 2000, 3000, and 4000 are connected in the same way as the first gear motor 100, with the motor shaft and input shaft connected via a float connection so that they can rotate as a single unit.

[0103] The first type gear motor 1000 is constructed from the first gear motor 100 described above, except for the dimensions of the reduction gear casing 1030. In other words, the adapter 1032 of the first type gear motor 1000 is fastened to the load-side motor cover 1018 from the non-load side by adapter bolts B2, similar to the first gear motor 100. This is advantageous in expanding the types of first type reduction gear 1004 that can be selected when standardizing motors 1002, 2002 with the first and second type reduction gears 1004, 2004 belonging to the first subseries S1, similar to (A) described above. Furthermore, the adapter bolts B2 of the first type gear motor 1000 are positioned radially outward from the reference pitch circle (not shown) where the motor bolts B3 that fasten the load-side motor cover 1018 and the motor frame of the first type motor 1002 are located, similar to the first gear motor 100. Furthermore, the aforementioned second gear motor 200 does not necessarily have to be part of the remaining second to fourth type gear motors 2000 to 4000.

[0104] The adapter 2032 of the Type 2 gear motor 2000 is also fastened to the load-side motor cover 2018 from the non-load side using adapter bolts B2. This is advantageous in expanding the types of Type 2 reducers 2004 that can be selected, when standardizing motors 1002, 2002 with Type 1, Type 2 reducers 1004, 2004 belonging to the first subseries S1, as described in (A) above. In addition, the adapter bolts B2 of the Type 2 gear motor 2000 are also positioned radially outward from the reference pitch circle (not shown) where the motor bolts B3 that fasten the load-side motor cover 2018 to the motor frame are located. Furthermore, the number and position of adapter bolts B2 used to fasten the adapters 1032, 2032 to the load-side motor covers 1018, 2018 are the same for all Type 1, Type 2 gear motors 1000, 2000.

[0105] The matters described here regarding the relationship between the Type 1 gear motor 1000 and the Type 2 gear motor 2000 also apply to the relationship between the Type 3 gear motor 3000 and the Type 4 gear motor 4000. For example, the adapters 3032 and 4032 of any of the Type 3, Type 4 gear motors 3000 and 4000 are fastened to the load-side motor cover 3018 and 4018 from the non-load side using adapter bolts B2. Furthermore, the number and position of the adapter bolts B2 used to fasten the adapters 3032 and 4032 to the load-side motor cover 3018 and 4018 are the same for all of the Type 3, Type 4 gear motors 3000 and 4000.

[0106] In the first to fourth type gear motors 4000, the features described for the first gear motor 100 may also be applied to matters other than those described herein. Furthermore, the features described in relation to the first and second gear motors 100 and 200 may also be applied to the first and second type gear motors 1000 and 2000, or to the third and fourth type gear motors 3000 and 4000. For example, similar to the first and second reduction gears 104 and 204, the shape of the input shaft side connection part of the input shafts of the first and second type reduction gears 1004 and 2004 may be the same. In addition, the shape of the input shaft side connection part of the input shafts of the third and fourth type reduction gears 3004 and 4004 may also be the same. Furthermore, similar to the first and second gearboxes 104 and 204, the shapes of the adapter mating surfaces of the adapters 1032 and 2032 of the first and second gearboxes 1004 and 2004, respectively, may be the same. In addition, the shapes of the adapter mating surfaces of the adapters 3032 and 4032 of the third and fourth gearboxes 3004 and 4004, respectively, may be the same.

[0107] Next, we will describe the transformation forms of each component described so far.

[0108] The specific examples of the reduction mechanisms 124 and 224 of each reduction gear 104 and 204 are not particularly limited. If the reduction mechanisms 124 and 224 are gear mechanisms, the gear mechanisms may include, for example, hypoid gear mechanisms, simple planetary gear mechanisms, orthogonal axis gear mechanisms, parallel axis gear mechanisms, etc., in addition to eccentric oscillating reduction mechanisms and flexible meshing reduction mechanisms. The specific types of flexible meshing reduction mechanisms are not particularly limited and may include cylindrical, top hat, cup, etc. The specific types of eccentric oscillating reduction mechanisms are not particularly limited and may include, for example, the center crank type described above, as well as a distribution type in which multiple crankshafts 138 are arranged at positions offset with respect to the rotation centerlines of the output members 126 and 226. The reduction mechanisms 124 and 224 are not limited to gear mechanisms and may include friction transmission mechanisms, etc. The same applies to the various reduction gears 1004, 2004, 3004, and 4004.

[0109] The number of motor shaft bearings 114 and input shaft bearings 134 is not particularly limited and may be one, two, or three or more. The shapes of the input shaft side connection portions 122a and 222a of the first and second input shafts 122 and 222 do not have to be the same.

[0110] The load-side motor covers 118 and 218 may be omitted, and the load-side motor shaft bearings 114A and 214A may be supported by the adapters 132 and 232, respectively. Alternatively, the adapters 132 and 232 may be omitted, and the non-load-side input shaft bearings 134B and 234B may be supported by the load-side motor covers 118 and 218.

[0111] The shapes of the adapter-side mating surfaces 132a and 232a of the first and second adapters 132 and 232 do not have to be the same. One or both of the first and second adapters 132 and 232 may be fastened to the load-side motor covers 118 and 218 from the load side using adapter bolts B2. The adapter bolts B2 may be positioned on the reference pitch circle PCa, or radially inward from the reference pitch circle PCa.

[0112] The relationship between the total radial internal clearances Ra and Rb of the bearings in the load transmission path between the gearbox casings 130, 230 or adapters 132, 232 and the input shafts 122, 222, and the clearance Rm of the radial clearances 152, 252, is not particularly limited. For example, Ra ≥ Rm and Rb ≥ Rm may be the case.

[0113] The axial gaps 170 and 270 may be zero when the motor shafts 106 and 206 are in the motor shaft restricting position Pc, or when the input shafts 122 and 222 are in either the input shaft restricting position Pd.

[0114] The contents of each component described in the embodiments above are illustrative. The abstract technical ideas derived from these should not be interpreted restrictively to the contents of this specification. Many design changes, such as modifications, additions, and deletions, are possible for the contents of each component described in the embodiments. Such modifications are emphasized by the notation "this form" and "embodiment." However, design changes are also permitted for contents without such notation. Any combination of the above components is also valid. For example, any explanatory items from other embodiments may be combined with an embodiment, and any explanatory items from an embodiment and other modified forms may be combined with a modified form. The hatching applied to the cross-section in the drawings does not limit the material of the object to which the hatching is applied. The structures and numerical values ​​mentioned in the embodiments and modified forms naturally include those that can be considered identical when considering manufacturing tolerances, etc. Components composed of a single member in the description in this specification may be composed of multiple members. Similarly, components composed of multiple members may be composed of a single member.

[0115] This disclosure relates to a series of gear motors.

[0116] 100...First gear motor, 102...First motor, 104...First reduction gear, 106...First motor shaft, 112...First motor casing, 116...First motor frame, 118...First load-side motor cover, 122...First input shaft, 122a...First input shaft side connection, 124...First reduction mechanism, 130...First reduction gear casing, 132...First adapter, 132a...First adapter side mating surface, 134...First input shaft bearing, 148...First one shaft, 150...First other shaft, 152...First radial clearance, 164...First motor shaft restricting structure, 166...First input shaft restricting structure, 170...First axial clearance. 200...Second gear motor, 202...Second motor, 204...Second reduction gear, 206...Second motor shaft, 212...Second motor casing, 216...Second motor frame, 218...Second load-side motor cover, 222...Second input shaft, 122a...Second input shaft side connection part, 224...Second reduction mechanism, 230...Second reduction gear casing, 232...Second adapter, 232a...Second adapter side mating surface, 234...Second input shaft bearing, 248...Second one shaft, 250...Second other shaft, 252...Second radial clearance, 264...Second motor shaft restricting structure, 266...Second input shaft restricting structure, 270...Second axial clearance. 1000...Type 1 gear motor, 1002...Type 1 motor, 1004...Type 1 reducer, 1012...Motor casing, 1018...Load-side motor cover, 1030...Reducer casing, 1032...Adapter. 2000...Type 2 gear motor, 2002...Type 2 motor, 2004...Type 2 reducer, 2012...Motor casing, 2018...Load-side motor cover, 2030...Reducer casing, 2032...Adapter.

Claims

1. A series of gear motors comprising a first gear motor and a second gear motor, wherein the first gear motor comprises a first motor and a first reduction gear, the second gear motor comprises a second motor common to the first motor and a second reduction gear, the first reduction gear comprises a first input shaft and a first reduction mechanism, the second reduction gear comprises a second input shaft and a second reduction mechanism different from the first reduction mechanism, the first input shaft is connected to the motor shaft of the first motor so as to be integrally rotatable by a float connection, and the second input shaft is connected to the motor shaft of the second motor so as to be integrally rotatable by a float connection.

2. The series of gear motors according to claim 1, wherein the first reduction gear comprises at least two first input shaft bearings capable of receiving a moment load acting on the first input shaft, and the second reduction gear comprises at least two second input shaft bearings capable of receiving a moment load acting on the second input shaft.

3. The series of gear motors according to claim 1 or 2, wherein each of the first input shaft and the second input shaft is provided with an input shaft side connection portion that is connected integrally with the motor shaft of the first motor and the second motor, respectively, and the shape of the input shaft side connection portion of the first input shaft and the second input shaft is the same.

4. The gear motor series according to claim 2, wherein each of the first motor and the second motor is provided with a load-side motor cover, the first reduction gear is provided with a first adapter connected to the first reduction gear casing and connected to the load-side motor cover of the first motor, and the second reduction gear is provided with a second adapter connected to the second reduction gear casing and connected to the load-side motor cover of the second motor.

5. The gear motor series according to claim 4, wherein each of the first adapter and the second adapter has an adapter-side fitting surface that engages with the load-side motor cover of the first motor and the second motor respectively, and the shape of the adapter-side fitting surface of each of the first adapter and the second adapter is the same.

6. The gear motor series according to claim 4 or 5, wherein the first adapter and the load-side motor cover of the first motor are fastened to the load-side motor cover from the non-load side by adapter bolts.

7. The gear motor series according to claim 6, wherein the second adapter and the load-side motor cover of the second motor are fastened to the load-side motor cover from the non-load side by adapter bolts.

8. The gear motor series according to claim 6 or 7, wherein each of the first motor and the second motor comprises a motor frame connected to the load-side motor cover, the motor frame and the load-side motor cover are fastened together by a plurality of motor bolts arranged on a reference pitch circle, and the adapter bolts fastening the first adapter and the load-side motor cover of the first motor are arranged radially outward from the reference pitch circle when viewed from the axial direction.

9. The series of gear motors according to claim 8, wherein the adapter bolts that fasten the second adapter and the load-side motor cover of the second motor are arranged radially outward from the reference pitch circle when viewed from the axial direction.

10. A series of gear motors according to any one of claims 1 to 9, wherein the first reduction gear comprises a first reduction gear casing, the first input shaft is rotatably supported by at least one bearing with respect to the first reduction gear casing or a first adapter connected to the first reduction gear casing, a first radial clearance is provided between the motor shaft and the first input shaft, and the total amount of radial internal clearance of the bearings in at least one load transmission path between the first reduction gear casing or the first adapter and the first input shaft is less than the amount of clearance of the first radial clearance.

11. A series of gear motors according to any one of claims 1 to 10, wherein each of the first motor and the second motor comprises a motor casing and a motor shaft restricting structure that restricts the axial movement of the motor shaft toward the load side relative to the motor casing, and the first reduction gear comprises a first reduction gear casing and a first input shaft restricting structure that restricts the movement of the first input shaft toward the non-load side relative to the first reduction gear casing or a first adapter connected to the first reduction gear casing, and a first axial gap is provided between the motor shaft and the first input shaft that allows relative movement of the first input shaft toward the non-load side relative to the motor shaft, and the first axial gap exists in a range greater than zero when the motor shaft is in a motor shaft restricting position where its movement toward the load side is restricted by the motor shaft restricting structure, and the first input shaft is in an input shaft restricting position where its movement toward the non-load side is restricted by the first input shaft restricting structure.

12. A series of gear motors according to any one of claims 6 to 9, comprising a subseries of gear motors having a first-type gear motor and a second-type gear motor, wherein the first-type gear motor comprises a first-type motor and a first-type reduction gear, the second-type gear motor comprises a second-type motor common to the first-type motor and a second-type reduction gear, the reduction gear casing of the first-type reduction gear is smaller than the reduction gear casing of the second-type reduction gear, and the first-type gear motor is composed of the first gear motor.

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